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Rename struct lib_ring_buffer_ctx to struct lttng_kernel_ring_buffer_ctx
[lttng-modules.git] / src / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
2 *
3 * lttng-events.c
4 *
5 * Holds LTTng per-session event registry.
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10 /*
11 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
12 * overrides a function with a define.
13 */
14 #include "wrapper/page_alloc.h"
15
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/jiffies.h>
21 #include <linux/utsname.h>
22 #include <linux/err.h>
23 #include <linux/seq_file.h>
24 #include <linux/file.h>
25 #include <linux/anon_inodes.h>
26 #include <wrapper/file.h>
27 #include <linux/uaccess.h>
28 #include <linux/vmalloc.h>
29 #include <linux/dmi.h>
30
31 #include <wrapper/uuid.h>
32 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
33 #include <wrapper/random.h>
34 #include <wrapper/tracepoint.h>
35 #include <wrapper/list.h>
36 #include <wrapper/types.h>
37 #include <lttng/kernel-version.h>
38 #include <lttng/events.h>
39 #include <lttng/events-internal.h>
40 #include <lttng/lttng-bytecode.h>
41 #include <lttng/tracer.h>
42 #include <lttng/event-notifier-notification.h>
43 #include <lttng/abi-old.h>
44 #include <lttng/endian.h>
45 #include <lttng/string-utils.h>
46 #include <lttng/utils.h>
47 #include <ringbuffer/backend.h>
48 #include <ringbuffer/frontend.h>
49 #include <wrapper/time.h>
50
51 #define METADATA_CACHE_DEFAULT_SIZE 4096
52
53 static LIST_HEAD(sessions);
54 static LIST_HEAD(event_notifier_groups);
55 static LIST_HEAD(lttng_transport_list);
56 static LIST_HEAD(lttng_counter_transport_list);
57 /*
58 * Protect the sessions and metadata caches.
59 */
60 static DEFINE_MUTEX(sessions_mutex);
61 static struct kmem_cache *event_recorder_cache;
62 static struct kmem_cache *event_recorder_private_cache;
63 static struct kmem_cache *event_notifier_cache;
64 static struct kmem_cache *event_notifier_private_cache;
65
66 static void lttng_session_lazy_sync_event_enablers(struct lttng_session *session);
67 static void lttng_session_sync_event_enablers(struct lttng_session *session);
68 static void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler);
69 static void lttng_event_notifier_enabler_destroy(struct lttng_event_notifier_enabler *event_notifier_enabler);
70 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
71
72 static void _lttng_event_destroy(struct lttng_kernel_event_common *event);
73 static void _lttng_channel_destroy(struct lttng_channel *chan);
74 static int _lttng_event_unregister(struct lttng_kernel_event_recorder *event);
75 static int _lttng_event_notifier_unregister(struct lttng_kernel_event_notifier *event_notifier);
76 static
77 int _lttng_event_metadata_statedump(struct lttng_session *session,
78 struct lttng_channel *chan,
79 struct lttng_kernel_event_recorder *event);
80 static
81 int _lttng_session_metadata_statedump(struct lttng_session *session);
82 static
83 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
84 static
85 int _lttng_type_statedump(struct lttng_session *session,
86 const struct lttng_kernel_type_common *type,
87 enum lttng_kernel_string_encoding parent_encoding,
88 size_t nesting);
89 static
90 int _lttng_field_statedump(struct lttng_session *session,
91 const struct lttng_kernel_event_field *field,
92 size_t nesting, const char **prev_field_name_p);
93
94 void synchronize_trace(void)
95 {
96 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0))
97 synchronize_rcu();
98 #else
99 synchronize_sched();
100 #endif
101
102 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
103 #ifdef CONFIG_PREEMPT_RT_FULL
104 synchronize_rcu();
105 #endif
106 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
107 #ifdef CONFIG_PREEMPT_RT
108 synchronize_rcu();
109 #endif
110 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
111 }
112
113 void lttng_lock_sessions(void)
114 {
115 mutex_lock(&sessions_mutex);
116 }
117
118 void lttng_unlock_sessions(void)
119 {
120 mutex_unlock(&sessions_mutex);
121 }
122
123 static struct lttng_transport *lttng_transport_find(const char *name)
124 {
125 struct lttng_transport *transport;
126
127 list_for_each_entry(transport, &lttng_transport_list, node) {
128 if (!strcmp(transport->name, name))
129 return transport;
130 }
131 return NULL;
132 }
133
134 /*
135 * Called with sessions lock held.
136 */
137 int lttng_session_active(void)
138 {
139 struct lttng_session *iter;
140
141 list_for_each_entry(iter, &sessions, list) {
142 if (iter->active)
143 return 1;
144 }
145 return 0;
146 }
147
148 struct lttng_session *lttng_session_create(void)
149 {
150 struct lttng_session *session;
151 struct lttng_metadata_cache *metadata_cache;
152 int i;
153
154 mutex_lock(&sessions_mutex);
155 session = lttng_kvzalloc(sizeof(struct lttng_session), GFP_KERNEL);
156 if (!session)
157 goto err;
158 INIT_LIST_HEAD(&session->chan);
159 INIT_LIST_HEAD(&session->events);
160 lttng_guid_gen(&session->uuid);
161
162 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
163 GFP_KERNEL);
164 if (!metadata_cache)
165 goto err_free_session;
166 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
167 if (!metadata_cache->data)
168 goto err_free_cache;
169 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
170 kref_init(&metadata_cache->refcount);
171 mutex_init(&metadata_cache->lock);
172 session->metadata_cache = metadata_cache;
173 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
174 memcpy(&metadata_cache->uuid, &session->uuid,
175 sizeof(metadata_cache->uuid));
176 INIT_LIST_HEAD(&session->enablers_head);
177 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
178 INIT_HLIST_HEAD(&session->events_ht.table[i]);
179 list_add(&session->list, &sessions);
180 session->pid_tracker.session = session;
181 session->pid_tracker.tracker_type = TRACKER_PID;
182 session->vpid_tracker.session = session;
183 session->vpid_tracker.tracker_type = TRACKER_VPID;
184 session->uid_tracker.session = session;
185 session->uid_tracker.tracker_type = TRACKER_UID;
186 session->vuid_tracker.session = session;
187 session->vuid_tracker.tracker_type = TRACKER_VUID;
188 session->gid_tracker.session = session;
189 session->gid_tracker.tracker_type = TRACKER_GID;
190 session->vgid_tracker.session = session;
191 session->vgid_tracker.tracker_type = TRACKER_VGID;
192 mutex_unlock(&sessions_mutex);
193 return session;
194
195 err_free_cache:
196 kfree(metadata_cache);
197 err_free_session:
198 lttng_kvfree(session);
199 err:
200 mutex_unlock(&sessions_mutex);
201 return NULL;
202 }
203
204 static
205 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
206 {
207 struct lttng_counter_transport *transport;
208
209 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
210 if (!strcmp(transport->name, name))
211 return transport;
212 }
213 return NULL;
214 }
215
216 struct lttng_counter *lttng_kernel_counter_create(
217 const char *counter_transport_name,
218 size_t number_dimensions, const size_t *dimensions_sizes)
219 {
220 struct lttng_counter *counter = NULL;
221 struct lttng_counter_transport *counter_transport = NULL;
222
223 counter_transport = lttng_counter_transport_find(counter_transport_name);
224 if (!counter_transport) {
225 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
226 counter_transport_name);
227 goto notransport;
228 }
229 if (!try_module_get(counter_transport->owner)) {
230 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
231 goto notransport;
232 }
233
234 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
235 if (!counter)
236 goto nomem;
237
238 /* Create event notifier error counter. */
239 counter->ops = &counter_transport->ops;
240 counter->transport = counter_transport;
241
242 counter->counter = counter->ops->counter_create(
243 number_dimensions, dimensions_sizes, 0);
244 if (!counter->counter) {
245 goto create_error;
246 }
247
248 return counter;
249
250 create_error:
251 lttng_kvfree(counter);
252 nomem:
253 if (counter_transport)
254 module_put(counter_transport->owner);
255 notransport:
256 return NULL;
257 }
258
259 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
260 {
261 struct lttng_transport *transport = NULL;
262 struct lttng_event_notifier_group *event_notifier_group;
263 const char *transport_name = "relay-event-notifier";
264 size_t subbuf_size = 4096; //TODO
265 size_t num_subbuf = 16; //TODO
266 unsigned int switch_timer_interval = 0;
267 unsigned int read_timer_interval = 0;
268 int i;
269
270 mutex_lock(&sessions_mutex);
271
272 transport = lttng_transport_find(transport_name);
273 if (!transport) {
274 printk(KERN_WARNING "LTTng: transport %s not found\n",
275 transport_name);
276 goto notransport;
277 }
278 if (!try_module_get(transport->owner)) {
279 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
280 transport_name);
281 goto notransport;
282 }
283
284 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
285 GFP_KERNEL);
286 if (!event_notifier_group)
287 goto nomem;
288
289 /*
290 * Initialize the ring buffer used to store event notifier
291 * notifications.
292 */
293 event_notifier_group->ops = &transport->ops;
294 event_notifier_group->chan = transport->ops.priv->channel_create(
295 transport_name, event_notifier_group, NULL,
296 subbuf_size, num_subbuf, switch_timer_interval,
297 read_timer_interval);
298 if (!event_notifier_group->chan)
299 goto create_error;
300
301 event_notifier_group->transport = transport;
302
303 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
304 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
305 for (i = 0; i < LTTNG_EVENT_NOTIFIER_HT_SIZE; i++)
306 INIT_HLIST_HEAD(&event_notifier_group->event_notifiers_ht.table[i]);
307
308 list_add(&event_notifier_group->node, &event_notifier_groups);
309
310 mutex_unlock(&sessions_mutex);
311
312 return event_notifier_group;
313
314 create_error:
315 lttng_kvfree(event_notifier_group);
316 nomem:
317 if (transport)
318 module_put(transport->owner);
319 notransport:
320 mutex_unlock(&sessions_mutex);
321 return NULL;
322 }
323
324 void metadata_cache_destroy(struct kref *kref)
325 {
326 struct lttng_metadata_cache *cache =
327 container_of(kref, struct lttng_metadata_cache, refcount);
328 vfree(cache->data);
329 kfree(cache);
330 }
331
332 void lttng_session_destroy(struct lttng_session *session)
333 {
334 struct lttng_channel *chan, *tmpchan;
335 struct lttng_kernel_event_recorder_private *event_recorder_priv, *tmpevent_recorder_priv;
336 struct lttng_metadata_stream *metadata_stream;
337 struct lttng_event_enabler *event_enabler, *tmp_event_enabler;
338 int ret;
339
340 mutex_lock(&sessions_mutex);
341 WRITE_ONCE(session->active, 0);
342 list_for_each_entry(chan, &session->chan, list) {
343 ret = lttng_syscalls_unregister_channel(chan);
344 WARN_ON(ret);
345 }
346 list_for_each_entry(event_recorder_priv, &session->events, node) {
347 ret = _lttng_event_unregister(event_recorder_priv->pub);
348 WARN_ON(ret);
349 }
350 synchronize_trace(); /* Wait for in-flight events to complete */
351 list_for_each_entry(chan, &session->chan, list) {
352 ret = lttng_syscalls_destroy_event(chan);
353 WARN_ON(ret);
354 }
355 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
356 &session->enablers_head, node)
357 lttng_event_enabler_destroy(event_enabler);
358 list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv, &session->events, node)
359 _lttng_event_destroy(&event_recorder_priv->pub->parent);
360 list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
361 BUG_ON(chan->channel_type == METADATA_CHANNEL);
362 _lttng_channel_destroy(chan);
363 }
364 mutex_lock(&session->metadata_cache->lock);
365 list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
366 _lttng_metadata_channel_hangup(metadata_stream);
367 mutex_unlock(&session->metadata_cache->lock);
368 lttng_id_tracker_destroy(&session->pid_tracker, false);
369 lttng_id_tracker_destroy(&session->vpid_tracker, false);
370 lttng_id_tracker_destroy(&session->uid_tracker, false);
371 lttng_id_tracker_destroy(&session->vuid_tracker, false);
372 lttng_id_tracker_destroy(&session->gid_tracker, false);
373 lttng_id_tracker_destroy(&session->vgid_tracker, false);
374 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
375 list_del(&session->list);
376 mutex_unlock(&sessions_mutex);
377 lttng_kvfree(session);
378 }
379
380 void lttng_event_notifier_group_destroy(
381 struct lttng_event_notifier_group *event_notifier_group)
382 {
383 struct lttng_event_notifier_enabler *event_notifier_enabler, *tmp_event_notifier_enabler;
384 struct lttng_kernel_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
385 int ret;
386
387 if (!event_notifier_group)
388 return;
389
390 mutex_lock(&sessions_mutex);
391
392 ret = lttng_syscalls_unregister_event_notifier_group(event_notifier_group);
393 WARN_ON(ret);
394
395 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
396 &event_notifier_group->event_notifiers_head, node) {
397 ret = _lttng_event_notifier_unregister(event_notifier_priv->pub);
398 WARN_ON(ret);
399 }
400
401 /* Wait for in-flight event notifier to complete */
402 synchronize_trace();
403
404 irq_work_sync(&event_notifier_group->wakeup_pending);
405
406 kfree(event_notifier_group->sc_filter);
407
408 list_for_each_entry_safe(event_notifier_enabler, tmp_event_notifier_enabler,
409 &event_notifier_group->enablers_head, node)
410 lttng_event_notifier_enabler_destroy(event_notifier_enabler);
411
412 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
413 &event_notifier_group->event_notifiers_head, node)
414 _lttng_event_destroy(&event_notifier_priv->pub->parent);
415
416 if (event_notifier_group->error_counter) {
417 struct lttng_counter *error_counter = event_notifier_group->error_counter;
418
419 error_counter->ops->counter_destroy(error_counter->counter);
420 module_put(error_counter->transport->owner);
421 lttng_kvfree(error_counter);
422 event_notifier_group->error_counter = NULL;
423 }
424
425 event_notifier_group->ops->priv->channel_destroy(event_notifier_group->chan);
426 module_put(event_notifier_group->transport->owner);
427 list_del(&event_notifier_group->node);
428
429 mutex_unlock(&sessions_mutex);
430 lttng_kvfree(event_notifier_group);
431 }
432
433 int lttng_session_statedump(struct lttng_session *session)
434 {
435 int ret;
436
437 mutex_lock(&sessions_mutex);
438 ret = lttng_statedump_start(session);
439 mutex_unlock(&sessions_mutex);
440 return ret;
441 }
442
443 int lttng_session_enable(struct lttng_session *session)
444 {
445 int ret = 0;
446 struct lttng_channel *chan;
447
448 mutex_lock(&sessions_mutex);
449 if (session->active) {
450 ret = -EBUSY;
451 goto end;
452 }
453
454 /* Set transient enabler state to "enabled" */
455 session->tstate = 1;
456
457 /* We need to sync enablers with session before activation. */
458 lttng_session_sync_event_enablers(session);
459
460 /*
461 * Snapshot the number of events per channel to know the type of header
462 * we need to use.
463 */
464 list_for_each_entry(chan, &session->chan, list) {
465 if (chan->header_type)
466 continue; /* don't change it if session stop/restart */
467 if (chan->free_event_id < 31)
468 chan->header_type = 1; /* compact */
469 else
470 chan->header_type = 2; /* large */
471 }
472
473 /* Clear each stream's quiescent state. */
474 list_for_each_entry(chan, &session->chan, list) {
475 if (chan->channel_type != METADATA_CHANNEL)
476 lib_ring_buffer_clear_quiescent_channel(chan->chan);
477 }
478
479 WRITE_ONCE(session->active, 1);
480 WRITE_ONCE(session->been_active, 1);
481 ret = _lttng_session_metadata_statedump(session);
482 if (ret) {
483 WRITE_ONCE(session->active, 0);
484 goto end;
485 }
486 ret = lttng_statedump_start(session);
487 if (ret)
488 WRITE_ONCE(session->active, 0);
489 end:
490 mutex_unlock(&sessions_mutex);
491 return ret;
492 }
493
494 int lttng_session_disable(struct lttng_session *session)
495 {
496 int ret = 0;
497 struct lttng_channel *chan;
498
499 mutex_lock(&sessions_mutex);
500 if (!session->active) {
501 ret = -EBUSY;
502 goto end;
503 }
504 WRITE_ONCE(session->active, 0);
505
506 /* Set transient enabler state to "disabled" */
507 session->tstate = 0;
508 lttng_session_sync_event_enablers(session);
509
510 /* Set each stream's quiescent state. */
511 list_for_each_entry(chan, &session->chan, list) {
512 if (chan->channel_type != METADATA_CHANNEL)
513 lib_ring_buffer_set_quiescent_channel(chan->chan);
514 }
515 end:
516 mutex_unlock(&sessions_mutex);
517 return ret;
518 }
519
520 int lttng_session_metadata_regenerate(struct lttng_session *session)
521 {
522 int ret = 0;
523 struct lttng_channel *chan;
524 struct lttng_kernel_event_recorder_private *event_recorder_priv;
525 struct lttng_metadata_cache *cache = session->metadata_cache;
526 struct lttng_metadata_stream *stream;
527
528 mutex_lock(&sessions_mutex);
529 if (!session->active) {
530 ret = -EBUSY;
531 goto end;
532 }
533
534 mutex_lock(&cache->lock);
535 memset(cache->data, 0, cache->cache_alloc);
536 cache->metadata_written = 0;
537 cache->version++;
538 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list) {
539 stream->metadata_out = 0;
540 stream->metadata_in = 0;
541 }
542 mutex_unlock(&cache->lock);
543
544 session->metadata_dumped = 0;
545 list_for_each_entry(chan, &session->chan, list) {
546 chan->metadata_dumped = 0;
547 }
548
549 list_for_each_entry(event_recorder_priv, &session->events, node) {
550 event_recorder_priv->metadata_dumped = 0;
551 }
552
553 ret = _lttng_session_metadata_statedump(session);
554
555 end:
556 mutex_unlock(&sessions_mutex);
557 return ret;
558 }
559
560 int lttng_channel_enable(struct lttng_channel *channel)
561 {
562 int ret = 0;
563
564 mutex_lock(&sessions_mutex);
565 if (channel->channel_type == METADATA_CHANNEL) {
566 ret = -EPERM;
567 goto end;
568 }
569 if (channel->enabled) {
570 ret = -EEXIST;
571 goto end;
572 }
573 /* Set transient enabler state to "enabled" */
574 channel->tstate = 1;
575 lttng_session_sync_event_enablers(channel->session);
576 /* Set atomically the state to "enabled" */
577 WRITE_ONCE(channel->enabled, 1);
578 end:
579 mutex_unlock(&sessions_mutex);
580 return ret;
581 }
582
583 int lttng_channel_disable(struct lttng_channel *channel)
584 {
585 int ret = 0;
586
587 mutex_lock(&sessions_mutex);
588 if (channel->channel_type == METADATA_CHANNEL) {
589 ret = -EPERM;
590 goto end;
591 }
592 if (!channel->enabled) {
593 ret = -EEXIST;
594 goto end;
595 }
596 /* Set atomically the state to "disabled" */
597 WRITE_ONCE(channel->enabled, 0);
598 /* Set transient enabler state to "enabled" */
599 channel->tstate = 0;
600 lttng_session_sync_event_enablers(channel->session);
601 end:
602 mutex_unlock(&sessions_mutex);
603 return ret;
604 }
605
606 int lttng_event_enable(struct lttng_kernel_event_common *event)
607 {
608 int ret = 0;
609
610 mutex_lock(&sessions_mutex);
611 switch (event->type) {
612 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
613 {
614 struct lttng_kernel_event_recorder *event_recorder =
615 container_of(event, struct lttng_kernel_event_recorder, parent);
616
617 if (event_recorder->chan->channel_type == METADATA_CHANNEL) {
618 ret = -EPERM;
619 goto end;
620 }
621 break;
622 }
623 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
624 switch (event->priv->instrumentation) {
625 case LTTNG_KERNEL_ABI_KRETPROBE:
626 ret = -EINVAL;
627 goto end;
628 default:
629 break;
630 }
631 break;
632 default:
633 break;
634 }
635
636 if (event->enabled) {
637 ret = -EEXIST;
638 goto end;
639 }
640 switch (event->priv->instrumentation) {
641 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
642 case LTTNG_KERNEL_ABI_SYSCALL:
643 ret = -EINVAL;
644 break;
645
646 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
647 case LTTNG_KERNEL_ABI_UPROBE:
648 WRITE_ONCE(event->enabled, 1);
649 break;
650
651 case LTTNG_KERNEL_ABI_KRETPROBE:
652 ret = lttng_kretprobes_event_enable_state(event, 1);
653 break;
654
655 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
656 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
657 default:
658 WARN_ON_ONCE(1);
659 ret = -EINVAL;
660 }
661 end:
662 mutex_unlock(&sessions_mutex);
663 return ret;
664 }
665
666 int lttng_event_disable(struct lttng_kernel_event_common *event)
667 {
668 int ret = 0;
669
670 mutex_lock(&sessions_mutex);
671 switch (event->type) {
672 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
673 {
674 struct lttng_kernel_event_recorder *event_recorder =
675 container_of(event, struct lttng_kernel_event_recorder, parent);
676
677 if (event_recorder->chan->channel_type == METADATA_CHANNEL) {
678 ret = -EPERM;
679 goto end;
680 }
681 break;
682 }
683 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
684 switch (event->priv->instrumentation) {
685 case LTTNG_KERNEL_ABI_KRETPROBE:
686 ret = -EINVAL;
687 goto end;
688 default:
689 break;
690 }
691 break;
692 default:
693 break;
694 }
695
696 if (!event->enabled) {
697 ret = -EEXIST;
698 goto end;
699 }
700 switch (event->priv->instrumentation) {
701 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
702 case LTTNG_KERNEL_ABI_SYSCALL:
703 ret = -EINVAL;
704 break;
705
706 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
707 case LTTNG_KERNEL_ABI_UPROBE:
708 WRITE_ONCE(event->enabled, 0);
709 break;
710
711 case LTTNG_KERNEL_ABI_KRETPROBE:
712 ret = lttng_kretprobes_event_enable_state(event, 0);
713 break;
714
715 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
716 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
717 default:
718 WARN_ON_ONCE(1);
719 ret = -EINVAL;
720 }
721 end:
722 mutex_unlock(&sessions_mutex);
723 return ret;
724 }
725
726 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
727 const char *transport_name,
728 void *buf_addr,
729 size_t subbuf_size, size_t num_subbuf,
730 unsigned int switch_timer_interval,
731 unsigned int read_timer_interval,
732 enum channel_type channel_type)
733 {
734 struct lttng_channel *chan;
735 struct lttng_transport *transport = NULL;
736
737 mutex_lock(&sessions_mutex);
738 if (session->been_active && channel_type != METADATA_CHANNEL)
739 goto active; /* Refuse to add channel to active session */
740 transport = lttng_transport_find(transport_name);
741 if (!transport) {
742 printk(KERN_WARNING "LTTng: transport %s not found\n",
743 transport_name);
744 goto notransport;
745 }
746 if (!try_module_get(transport->owner)) {
747 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
748 goto notransport;
749 }
750 chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL);
751 if (!chan)
752 goto nomem;
753 chan->session = session;
754 chan->id = session->free_chan_id++;
755 chan->ops = &transport->ops;
756 /*
757 * Note: the channel creation op already writes into the packet
758 * headers. Therefore the "chan" information used as input
759 * should be already accessible.
760 */
761 chan->chan = transport->ops.priv->channel_create(transport_name,
762 chan, buf_addr, subbuf_size, num_subbuf,
763 switch_timer_interval, read_timer_interval);
764 if (!chan->chan)
765 goto create_error;
766 chan->tstate = 1;
767 chan->enabled = 1;
768 chan->transport = transport;
769 chan->channel_type = channel_type;
770 list_add(&chan->list, &session->chan);
771 mutex_unlock(&sessions_mutex);
772 return chan;
773
774 create_error:
775 kfree(chan);
776 nomem:
777 if (transport)
778 module_put(transport->owner);
779 notransport:
780 active:
781 mutex_unlock(&sessions_mutex);
782 return NULL;
783 }
784
785 /*
786 * Only used internally at session destruction for per-cpu channels, and
787 * when metadata channel is released.
788 * Needs to be called with sessions mutex held.
789 */
790 static
791 void _lttng_channel_destroy(struct lttng_channel *chan)
792 {
793 chan->ops->priv->channel_destroy(chan->chan);
794 module_put(chan->transport->owner);
795 list_del(&chan->list);
796 lttng_kernel_destroy_context(chan->ctx);
797 kfree(chan);
798 }
799
800 void lttng_metadata_channel_destroy(struct lttng_channel *chan)
801 {
802 BUG_ON(chan->channel_type != METADATA_CHANNEL);
803
804 /* Protect the metadata cache with the sessions_mutex. */
805 mutex_lock(&sessions_mutex);
806 _lttng_channel_destroy(chan);
807 mutex_unlock(&sessions_mutex);
808 }
809 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
810
811 static
812 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
813 {
814 stream->finalized = 1;
815 wake_up_interruptible(&stream->read_wait);
816 }
817
818
819 /*
820 * Supports event creation while tracing session is active.
821 * Needs to be called with sessions mutex held.
822 */
823 struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_channel *chan,
824 struct lttng_kernel_abi_event *event_param,
825 const struct lttng_kernel_event_desc *event_desc,
826 enum lttng_kernel_abi_instrumentation itype)
827 {
828 struct lttng_session *session = chan->session;
829 struct lttng_kernel_event_recorder *event_recorder;
830 struct lttng_kernel_event_recorder_private *event_recorder_priv;
831 const char *event_name;
832 struct hlist_head *head;
833 int ret;
834
835 if (chan->free_event_id == -1U) {
836 ret = -EMFILE;
837 goto full;
838 }
839
840 switch (itype) {
841 case LTTNG_KERNEL_ABI_TRACEPOINT:
842 event_name = event_desc->event_name;
843 break;
844
845 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
846 case LTTNG_KERNEL_ABI_UPROBE: /* Fall-through */
847 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
848 case LTTNG_KERNEL_ABI_SYSCALL:
849 event_name = event_param->name;
850 break;
851
852 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
853 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
854 default:
855 WARN_ON_ONCE(1);
856 ret = -EINVAL;
857 goto type_error;
858 }
859
860 head = utils_borrow_hash_table_bucket(session->events_ht.table,
861 LTTNG_EVENT_HT_SIZE, event_name);
862 lttng_hlist_for_each_entry(event_recorder_priv, head, hlist) {
863 WARN_ON_ONCE(!event_recorder_priv->parent.desc);
864 if (!strncmp(event_recorder_priv->parent.desc->event_name, event_name,
865 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
866 && chan == event_recorder_priv->pub->chan) {
867 ret = -EEXIST;
868 goto exist;
869 }
870 }
871
872 event_recorder = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
873 if (!event_recorder) {
874 ret = -ENOMEM;
875 goto cache_error;
876 }
877 event_recorder_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
878 if (!event_recorder_priv) {
879 ret = -ENOMEM;
880 goto cache_private_error;
881 }
882 event_recorder_priv->pub = event_recorder;
883 event_recorder_priv->parent.pub = &event_recorder->parent;
884 event_recorder->priv = event_recorder_priv;
885 event_recorder->parent.priv = &event_recorder_priv->parent;
886 event_recorder->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
887
888 event_recorder->parent.run_filter = lttng_kernel_interpret_event_filter;
889 event_recorder->chan = chan;
890 event_recorder->priv->id = chan->free_event_id++;
891 event_recorder->priv->parent.instrumentation = itype;
892 INIT_LIST_HEAD(&event_recorder->priv->parent.filter_bytecode_runtime_head);
893 INIT_LIST_HEAD(&event_recorder->priv->parent.enablers_ref_head);
894
895 switch (itype) {
896 case LTTNG_KERNEL_ABI_TRACEPOINT:
897 /* Event will be enabled by enabler sync. */
898 event_recorder->parent.enabled = 0;
899 event_recorder->priv->parent.registered = 0;
900 event_recorder->priv->parent.desc = lttng_event_desc_get(event_name);
901 if (!event_recorder->priv->parent.desc) {
902 ret = -ENOENT;
903 goto register_error;
904 }
905 /* Populate lttng_event structure before event registration. */
906 smp_wmb();
907 break;
908
909 case LTTNG_KERNEL_ABI_KPROBE:
910 /*
911 * Needs to be explicitly enabled after creation, since
912 * we may want to apply filters.
913 */
914 event_recorder->parent.enabled = 0;
915 event_recorder->priv->parent.registered = 1;
916 /*
917 * Populate lttng_event structure before event
918 * registration.
919 */
920 smp_wmb();
921 ret = lttng_kprobes_register_event(event_name,
922 event_param->u.kprobe.symbol_name,
923 event_param->u.kprobe.offset,
924 event_param->u.kprobe.addr,
925 event_recorder);
926 if (ret) {
927 ret = -EINVAL;
928 goto register_error;
929 }
930 ret = try_module_get(event_recorder->priv->parent.desc->owner);
931 WARN_ON_ONCE(!ret);
932 break;
933
934 case LTTNG_KERNEL_ABI_KRETPROBE:
935 {
936 struct lttng_kernel_event_recorder *event_recorder_return;
937 struct lttng_kernel_event_recorder_private *event_recorder_return_priv;
938
939 /* kretprobe defines 2 events */
940 /*
941 * Needs to be explicitly enabled after creation, since
942 * we may want to apply filters.
943 */
944 event_recorder->parent.enabled = 0;
945 event_recorder->priv->parent.registered = 1;
946
947 event_recorder_return = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
948 if (!event_recorder_return) {
949 ret = -ENOMEM;
950 goto register_error;
951 }
952 event_recorder_return_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
953 if (!event_recorder_return_priv) {
954 kmem_cache_free(event_recorder_cache, event_recorder_return);
955 ret = -ENOMEM;
956 goto register_error;
957 }
958 event_recorder_return_priv->pub = event_recorder_return;
959 event_recorder_return_priv->parent.pub = &event_recorder_return->parent;
960 event_recorder_return->priv = event_recorder_return_priv;
961 event_recorder_return->parent.priv = &event_recorder_return_priv->parent;
962 event_recorder_return->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
963
964 event_recorder_return->parent.run_filter = lttng_kernel_interpret_event_filter;
965 event_recorder_return->chan = chan;
966 event_recorder_return->priv->id = chan->free_event_id++;
967 event_recorder_return->priv->parent.instrumentation = itype;
968 event_recorder_return->parent.enabled = 0;
969 event_recorder_return->priv->parent.registered = 1;
970 INIT_LIST_HEAD(&event_recorder_return->priv->parent.filter_bytecode_runtime_head);
971 INIT_LIST_HEAD(&event_recorder_return->priv->parent.enablers_ref_head);
972 /*
973 * Populate lttng_event structure before kretprobe registration.
974 */
975 smp_wmb();
976 ret = lttng_kretprobes_register(event_name,
977 event_param->u.kretprobe.symbol_name,
978 event_param->u.kretprobe.offset,
979 event_param->u.kretprobe.addr,
980 event_recorder, event_recorder_return);
981 if (ret) {
982 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
983 kmem_cache_free(event_recorder_cache, event_recorder_return);
984 ret = -EINVAL;
985 goto register_error;
986 }
987 /* Take 2 refs on the module: one per event. */
988 ret = try_module_get(event_recorder->priv->parent.desc->owner);
989 WARN_ON_ONCE(!ret);
990 ret = try_module_get(event_recorder_return->priv->parent.desc->owner);
991 WARN_ON_ONCE(!ret);
992 ret = _lttng_event_metadata_statedump(chan->session, chan,
993 event_recorder_return);
994 WARN_ON_ONCE(ret > 0);
995 if (ret) {
996 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
997 kmem_cache_free(event_recorder_cache, event_recorder_return);
998 module_put(event_recorder_return->priv->parent.desc->owner);
999 module_put(event_recorder->priv->parent.desc->owner);
1000 goto statedump_error;
1001 }
1002 list_add(&event_recorder_return->priv->node, &chan->session->events);
1003 break;
1004 }
1005
1006 case LTTNG_KERNEL_ABI_SYSCALL:
1007 /*
1008 * Needs to be explicitly enabled after creation, since
1009 * we may want to apply filters.
1010 */
1011 event_recorder->parent.enabled = 0;
1012 event_recorder->priv->parent.registered = 0;
1013 event_recorder->priv->parent.desc = event_desc;
1014 switch (event_param->u.syscall.entryexit) {
1015 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1016 ret = -EINVAL;
1017 goto register_error;
1018 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1019 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1020 break;
1021 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1022 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1023 break;
1024 }
1025 switch (event_param->u.syscall.abi) {
1026 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1027 ret = -EINVAL;
1028 goto register_error;
1029 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1030 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1031 break;
1032 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1033 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1034 break;
1035 }
1036 if (!event_recorder->priv->parent.desc) {
1037 ret = -EINVAL;
1038 goto register_error;
1039 }
1040 break;
1041
1042 case LTTNG_KERNEL_ABI_UPROBE:
1043 /*
1044 * Needs to be explicitly enabled after creation, since
1045 * we may want to apply filters.
1046 */
1047 event_recorder->parent.enabled = 0;
1048 event_recorder->priv->parent.registered = 1;
1049
1050 /*
1051 * Populate lttng_event structure before event
1052 * registration.
1053 */
1054 smp_wmb();
1055
1056 ret = lttng_uprobes_register_event(event_param->name,
1057 event_param->u.uprobe.fd,
1058 event_recorder);
1059 if (ret)
1060 goto register_error;
1061 ret = try_module_get(event_recorder->priv->parent.desc->owner);
1062 WARN_ON_ONCE(!ret);
1063 break;
1064
1065 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1066 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1067 default:
1068 WARN_ON_ONCE(1);
1069 ret = -EINVAL;
1070 goto register_error;
1071 }
1072 ret = _lttng_event_metadata_statedump(chan->session, chan, event_recorder);
1073 WARN_ON_ONCE(ret > 0);
1074 if (ret) {
1075 goto statedump_error;
1076 }
1077 hlist_add_head(&event_recorder->priv->hlist, head);
1078 list_add(&event_recorder->priv->node, &chan->session->events);
1079 return event_recorder;
1080
1081 statedump_error:
1082 /* If a statedump error occurs, events will not be readable. */
1083 register_error:
1084 kmem_cache_free(event_recorder_private_cache, event_recorder_priv);
1085 cache_private_error:
1086 kmem_cache_free(event_recorder_cache, event_recorder);
1087 cache_error:
1088 exist:
1089 type_error:
1090 full:
1091 return ERR_PTR(ret);
1092 }
1093
1094 struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
1095 const struct lttng_kernel_event_desc *event_desc,
1096 uint64_t token, uint64_t error_counter_index,
1097 struct lttng_event_notifier_group *event_notifier_group,
1098 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1099 enum lttng_kernel_abi_instrumentation itype)
1100 {
1101 struct lttng_kernel_event_notifier *event_notifier;
1102 struct lttng_kernel_event_notifier_private *event_notifier_priv;
1103 struct lttng_counter *error_counter;
1104 const char *event_name;
1105 struct hlist_head *head;
1106 int ret;
1107
1108 switch (itype) {
1109 case LTTNG_KERNEL_ABI_TRACEPOINT:
1110 event_name = event_desc->event_name;
1111 break;
1112
1113 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
1114 case LTTNG_KERNEL_ABI_UPROBE: /* Fall-through */
1115 case LTTNG_KERNEL_ABI_SYSCALL:
1116 event_name = event_notifier_param->event.name;
1117 break;
1118
1119 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1120 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1121 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1122 default:
1123 WARN_ON_ONCE(1);
1124 ret = -EINVAL;
1125 goto type_error;
1126 }
1127
1128 head = utils_borrow_hash_table_bucket(event_notifier_group->event_notifiers_ht.table,
1129 LTTNG_EVENT_NOTIFIER_HT_SIZE, event_name);
1130 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
1131 WARN_ON_ONCE(!event_notifier_priv->parent.desc);
1132 if (!strncmp(event_notifier_priv->parent.desc->event_name, event_name,
1133 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
1134 && event_notifier_group == event_notifier_priv->group
1135 && token == event_notifier_priv->parent.user_token) {
1136 ret = -EEXIST;
1137 goto exist;
1138 }
1139 }
1140
1141 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
1142 if (!event_notifier) {
1143 ret = -ENOMEM;
1144 goto cache_error;
1145 }
1146 event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
1147 if (!event_notifier_priv) {
1148 ret = -ENOMEM;
1149 goto cache_private_error;
1150 }
1151 event_notifier_priv->pub = event_notifier;
1152 event_notifier_priv->parent.pub = &event_notifier->parent;
1153 event_notifier->priv = event_notifier_priv;
1154 event_notifier->parent.priv = &event_notifier_priv->parent;
1155 event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
1156
1157 event_notifier->priv->group = event_notifier_group;
1158 event_notifier->priv->parent.user_token = token;
1159 event_notifier->priv->error_counter_index = error_counter_index;
1160 event_notifier->priv->num_captures = 0;
1161 event_notifier->priv->parent.instrumentation = itype;
1162 event_notifier->notification_send = lttng_event_notifier_notification_send;
1163 INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
1164 INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
1165 INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
1166 event_notifier->parent.run_filter = lttng_kernel_interpret_event_filter;
1167
1168 switch (itype) {
1169 case LTTNG_KERNEL_ABI_TRACEPOINT:
1170 /* Event will be enabled by enabler sync. */
1171 event_notifier->parent.enabled = 0;
1172 event_notifier->priv->parent.registered = 0;
1173 event_notifier->priv->parent.desc = lttng_event_desc_get(event_name);
1174 if (!event_notifier->priv->parent.desc) {
1175 ret = -ENOENT;
1176 goto register_error;
1177 }
1178 /* Populate lttng_event_notifier structure before event registration. */
1179 smp_wmb();
1180 break;
1181
1182 case LTTNG_KERNEL_ABI_KPROBE:
1183 /*
1184 * Needs to be explicitly enabled after creation, since
1185 * we may want to apply filters.
1186 */
1187 event_notifier->parent.enabled = 0;
1188 event_notifier->priv->parent.registered = 1;
1189 /*
1190 * Populate lttng_event_notifier structure before event
1191 * registration.
1192 */
1193 smp_wmb();
1194 ret = lttng_kprobes_register_event_notifier(
1195 event_notifier_param->event.u.kprobe.symbol_name,
1196 event_notifier_param->event.u.kprobe.offset,
1197 event_notifier_param->event.u.kprobe.addr,
1198 event_notifier);
1199 if (ret) {
1200 ret = -EINVAL;
1201 goto register_error;
1202 }
1203 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1204 WARN_ON_ONCE(!ret);
1205 break;
1206
1207 case LTTNG_KERNEL_ABI_SYSCALL:
1208 /*
1209 * Needs to be explicitly enabled after creation, since
1210 * we may want to apply filters.
1211 */
1212 event_notifier->parent.enabled = 0;
1213 event_notifier->priv->parent.registered = 0;
1214 event_notifier->priv->parent.desc = event_desc;
1215 switch (event_notifier_param->event.u.syscall.entryexit) {
1216 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1217 ret = -EINVAL;
1218 goto register_error;
1219 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1220 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1221 break;
1222 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1223 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1224 break;
1225 }
1226 switch (event_notifier_param->event.u.syscall.abi) {
1227 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1228 ret = -EINVAL;
1229 goto register_error;
1230 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1231 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1232 break;
1233 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1234 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1235 break;
1236 }
1237
1238 if (!event_notifier->priv->parent.desc) {
1239 ret = -EINVAL;
1240 goto register_error;
1241 }
1242 break;
1243
1244 case LTTNG_KERNEL_ABI_UPROBE:
1245 /*
1246 * Needs to be explicitly enabled after creation, since
1247 * we may want to apply filters.
1248 */
1249 event_notifier->parent.enabled = 0;
1250 event_notifier->priv->parent.registered = 1;
1251
1252 /*
1253 * Populate lttng_event_notifier structure before
1254 * event_notifier registration.
1255 */
1256 smp_wmb();
1257
1258 ret = lttng_uprobes_register_event_notifier(
1259 event_notifier_param->event.name,
1260 event_notifier_param->event.u.uprobe.fd,
1261 event_notifier);
1262 if (ret)
1263 goto register_error;
1264 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1265 WARN_ON_ONCE(!ret);
1266 break;
1267
1268 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1269 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1270 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1271 default:
1272 WARN_ON_ONCE(1);
1273 ret = -EINVAL;
1274 goto register_error;
1275 }
1276
1277 list_add(&event_notifier->priv->node, &event_notifier_group->event_notifiers_head);
1278 hlist_add_head(&event_notifier->priv->hlist, head);
1279
1280 /*
1281 * Clear the error counter bucket. The sessiond keeps track of which
1282 * bucket is currently in use. We trust it. The session lock
1283 * synchronizes against concurrent creation of the error
1284 * counter.
1285 */
1286 error_counter = event_notifier_group->error_counter;
1287 if (error_counter) {
1288 size_t dimension_index[1];
1289
1290 /*
1291 * Check that the index is within the boundary of the counter.
1292 */
1293 if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
1294 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1295 event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
1296 ret = -EINVAL;
1297 goto register_error;
1298 }
1299
1300 dimension_index[0] = event_notifier->priv->error_counter_index;
1301 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1302 if (ret) {
1303 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1304 event_notifier->priv->error_counter_index);
1305 goto register_error;
1306 }
1307 }
1308
1309 return event_notifier;
1310
1311 register_error:
1312 kmem_cache_free(event_notifier_private_cache, event_notifier_priv);
1313 cache_private_error:
1314 kmem_cache_free(event_notifier_cache, event_notifier);
1315 cache_error:
1316 exist:
1317 type_error:
1318 return ERR_PTR(ret);
1319 }
1320
1321 int lttng_kernel_counter_read(struct lttng_counter *counter,
1322 const size_t *dim_indexes, int32_t cpu,
1323 int64_t *val, bool *overflow, bool *underflow)
1324 {
1325 return counter->ops->counter_read(counter->counter, dim_indexes,
1326 cpu, val, overflow, underflow);
1327 }
1328
1329 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1330 const size_t *dim_indexes, int64_t *val,
1331 bool *overflow, bool *underflow)
1332 {
1333 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1334 val, overflow, underflow);
1335 }
1336
1337 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1338 const size_t *dim_indexes)
1339 {
1340 return counter->ops->counter_clear(counter->counter, dim_indexes);
1341 }
1342
1343 struct lttng_kernel_event_recorder *lttng_kernel_event_recorder_create(struct lttng_channel *chan,
1344 struct lttng_kernel_abi_event *event_param,
1345 const struct lttng_kernel_event_desc *event_desc,
1346 enum lttng_kernel_abi_instrumentation itype)
1347 {
1348 struct lttng_kernel_event_recorder *event;
1349
1350 mutex_lock(&sessions_mutex);
1351 event = _lttng_kernel_event_recorder_create(chan, event_param, event_desc, itype);
1352 mutex_unlock(&sessions_mutex);
1353 return event;
1354 }
1355
1356 struct lttng_kernel_event_notifier *lttng_event_notifier_create(
1357 const struct lttng_kernel_event_desc *event_desc,
1358 uint64_t id, uint64_t error_counter_index,
1359 struct lttng_event_notifier_group *event_notifier_group,
1360 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1361 enum lttng_kernel_abi_instrumentation itype)
1362 {
1363 struct lttng_kernel_event_notifier *event_notifier;
1364
1365 mutex_lock(&sessions_mutex);
1366 event_notifier = _lttng_event_notifier_create(event_desc, id,
1367 error_counter_index, event_notifier_group,
1368 event_notifier_param, itype);
1369 mutex_unlock(&sessions_mutex);
1370 return event_notifier;
1371 }
1372
1373 /* Only used for tracepoints for now. */
1374 static
1375 void register_event(struct lttng_kernel_event_recorder *event_recorder)
1376 {
1377 const struct lttng_kernel_event_desc *desc;
1378 int ret = -EINVAL;
1379
1380 if (event_recorder->priv->parent.registered)
1381 return;
1382
1383 desc = event_recorder->priv->parent.desc;
1384 switch (event_recorder->priv->parent.instrumentation) {
1385 case LTTNG_KERNEL_ABI_TRACEPOINT:
1386 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1387 desc->probe_callback,
1388 event_recorder);
1389 break;
1390
1391 case LTTNG_KERNEL_ABI_SYSCALL:
1392 ret = lttng_syscall_filter_enable_event(event_recorder->chan, event_recorder);
1393 break;
1394
1395 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
1396 case LTTNG_KERNEL_ABI_UPROBE: /* Fall-through */
1397 case LTTNG_KERNEL_ABI_KRETPROBE:
1398 ret = 0;
1399 break;
1400
1401 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1402 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1403 default:
1404 WARN_ON_ONCE(1);
1405 }
1406 if (!ret)
1407 event_recorder->priv->parent.registered = 1;
1408 }
1409
1410 /*
1411 * Only used internally at session destruction.
1412 */
1413 int _lttng_event_unregister(struct lttng_kernel_event_recorder *event_recorder)
1414 {
1415 struct lttng_kernel_event_common_private *event_priv = &event_recorder->priv->parent;
1416 const struct lttng_kernel_event_desc *desc;
1417 int ret = -EINVAL;
1418
1419 if (!event_priv->registered)
1420 return 0;
1421
1422 desc = event_priv->desc;
1423 switch (event_priv->instrumentation) {
1424 case LTTNG_KERNEL_ABI_TRACEPOINT:
1425 ret = lttng_wrapper_tracepoint_probe_unregister(event_priv->desc->event_kname,
1426 event_priv->desc->probe_callback,
1427 event_recorder);
1428 break;
1429
1430 case LTTNG_KERNEL_ABI_KPROBE:
1431 lttng_kprobes_unregister_event(event_recorder);
1432 ret = 0;
1433 break;
1434
1435 case LTTNG_KERNEL_ABI_KRETPROBE:
1436 lttng_kretprobes_unregister(event_recorder);
1437 ret = 0;
1438 break;
1439
1440 case LTTNG_KERNEL_ABI_SYSCALL:
1441 ret = lttng_syscall_filter_disable_event(event_recorder->chan, event_recorder);
1442 break;
1443
1444 case LTTNG_KERNEL_ABI_NOOP:
1445 ret = 0;
1446 break;
1447
1448 case LTTNG_KERNEL_ABI_UPROBE:
1449 lttng_uprobes_unregister_event(event_recorder);
1450 ret = 0;
1451 break;
1452
1453 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1454 default:
1455 WARN_ON_ONCE(1);
1456 }
1457 if (!ret)
1458 event_priv->registered = 0;
1459 return ret;
1460 }
1461
1462 /* Only used for tracepoints for now. */
1463 static
1464 void register_event_notifier(struct lttng_kernel_event_notifier *event_notifier)
1465 {
1466 const struct lttng_kernel_event_desc *desc;
1467 int ret = -EINVAL;
1468
1469 if (event_notifier->priv->parent.registered)
1470 return;
1471
1472 desc = event_notifier->priv->parent.desc;
1473 switch (event_notifier->priv->parent.instrumentation) {
1474 case LTTNG_KERNEL_ABI_TRACEPOINT:
1475 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1476 desc->probe_callback,
1477 event_notifier);
1478 break;
1479
1480 case LTTNG_KERNEL_ABI_SYSCALL:
1481 ret = lttng_syscall_filter_enable_event_notifier(event_notifier);
1482 break;
1483
1484 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
1485 case LTTNG_KERNEL_ABI_UPROBE:
1486 ret = 0;
1487 break;
1488
1489 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1490 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1491 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1492 default:
1493 WARN_ON_ONCE(1);
1494 }
1495 if (!ret)
1496 event_notifier->priv->parent.registered = 1;
1497 }
1498
1499 static
1500 int _lttng_event_notifier_unregister(
1501 struct lttng_kernel_event_notifier *event_notifier)
1502 {
1503 const struct lttng_kernel_event_desc *desc;
1504 int ret = -EINVAL;
1505
1506 if (!event_notifier->priv->parent.registered)
1507 return 0;
1508
1509 desc = event_notifier->priv->parent.desc;
1510 switch (event_notifier->priv->parent.instrumentation) {
1511 case LTTNG_KERNEL_ABI_TRACEPOINT:
1512 ret = lttng_wrapper_tracepoint_probe_unregister(event_notifier->priv->parent.desc->event_kname,
1513 event_notifier->priv->parent.desc->probe_callback,
1514 event_notifier);
1515 break;
1516
1517 case LTTNG_KERNEL_ABI_KPROBE:
1518 lttng_kprobes_unregister_event_notifier(event_notifier);
1519 ret = 0;
1520 break;
1521
1522 case LTTNG_KERNEL_ABI_UPROBE:
1523 lttng_uprobes_unregister_event_notifier(event_notifier);
1524 ret = 0;
1525 break;
1526
1527 case LTTNG_KERNEL_ABI_SYSCALL:
1528 ret = lttng_syscall_filter_disable_event_notifier(event_notifier);
1529 break;
1530
1531 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1532 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1533 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1534 default:
1535 WARN_ON_ONCE(1);
1536 }
1537 if (!ret)
1538 event_notifier->priv->parent.registered = 0;
1539 return ret;
1540 }
1541
1542 /*
1543 * Only used internally at session destruction.
1544 */
1545 static
1546 void _lttng_event_destroy(struct lttng_kernel_event_common *event)
1547 {
1548 struct lttng_kernel_event_common_private *event_priv = event->priv;
1549 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1550
1551 lttng_free_event_filter_runtime(event);
1552 /* Free event enabler refs */
1553 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1554 &event_priv->enablers_ref_head, node)
1555 kfree(enabler_ref);
1556
1557 switch (event->type) {
1558 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1559 {
1560 struct lttng_kernel_event_recorder *event_recorder =
1561 container_of(event, struct lttng_kernel_event_recorder, parent);
1562
1563 switch (event_priv->instrumentation) {
1564 case LTTNG_KERNEL_ABI_TRACEPOINT:
1565 lttng_event_desc_put(event_priv->desc);
1566 break;
1567
1568 case LTTNG_KERNEL_ABI_KPROBE:
1569 module_put(event_priv->desc->owner);
1570 lttng_kprobes_destroy_event_private(event_recorder);
1571 break;
1572
1573 case LTTNG_KERNEL_ABI_KRETPROBE:
1574 module_put(event_priv->desc->owner);
1575 lttng_kretprobes_destroy_private(event_recorder);
1576 break;
1577
1578 case LTTNG_KERNEL_ABI_SYSCALL:
1579 break;
1580
1581 case LTTNG_KERNEL_ABI_UPROBE:
1582 module_put(event_priv->desc->owner);
1583 lttng_uprobes_destroy_event_private(event_recorder);
1584 break;
1585
1586 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1587 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1588 default:
1589 WARN_ON_ONCE(1);
1590 }
1591 list_del(&event_recorder->priv->node);
1592 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
1593 kmem_cache_free(event_recorder_cache, event_recorder);
1594 break;
1595 }
1596 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1597 {
1598 struct lttng_kernel_event_notifier *event_notifier =
1599 container_of(event, struct lttng_kernel_event_notifier, parent);
1600
1601 switch (event_notifier->priv->parent.instrumentation) {
1602 case LTTNG_KERNEL_ABI_TRACEPOINT:
1603 lttng_event_desc_put(event_notifier->priv->parent.desc);
1604 break;
1605
1606 case LTTNG_KERNEL_ABI_KPROBE:
1607 module_put(event_notifier->priv->parent.desc->owner);
1608 lttng_kprobes_destroy_event_notifier_private(event_notifier);
1609 break;
1610
1611 case LTTNG_KERNEL_ABI_SYSCALL:
1612 break;
1613
1614 case LTTNG_KERNEL_ABI_UPROBE:
1615 module_put(event_notifier->priv->parent.desc->owner);
1616 lttng_uprobes_destroy_event_notifier_private(event_notifier);
1617 break;
1618
1619 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1620 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1621 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1622 default:
1623 WARN_ON_ONCE(1);
1624 }
1625 list_del(&event_notifier->priv->node);
1626 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1627 kmem_cache_free(event_notifier_cache, event_notifier);
1628 break;
1629 }
1630 default:
1631 WARN_ON_ONCE(1);
1632 }
1633 }
1634
1635 struct lttng_id_tracker *get_tracker(struct lttng_session *session,
1636 enum tracker_type tracker_type)
1637 {
1638 switch (tracker_type) {
1639 case TRACKER_PID:
1640 return &session->pid_tracker;
1641 case TRACKER_VPID:
1642 return &session->vpid_tracker;
1643 case TRACKER_UID:
1644 return &session->uid_tracker;
1645 case TRACKER_VUID:
1646 return &session->vuid_tracker;
1647 case TRACKER_GID:
1648 return &session->gid_tracker;
1649 case TRACKER_VGID:
1650 return &session->vgid_tracker;
1651 default:
1652 WARN_ON_ONCE(1);
1653 return NULL;
1654 }
1655 }
1656
1657 int lttng_session_track_id(struct lttng_session *session,
1658 enum tracker_type tracker_type, int id)
1659 {
1660 struct lttng_id_tracker *tracker;
1661 int ret;
1662
1663 tracker = get_tracker(session, tracker_type);
1664 if (!tracker)
1665 return -EINVAL;
1666 if (id < -1)
1667 return -EINVAL;
1668 mutex_lock(&sessions_mutex);
1669 if (id == -1) {
1670 /* track all ids: destroy tracker. */
1671 lttng_id_tracker_destroy(tracker, true);
1672 ret = 0;
1673 } else {
1674 ret = lttng_id_tracker_add(tracker, id);
1675 }
1676 mutex_unlock(&sessions_mutex);
1677 return ret;
1678 }
1679
1680 int lttng_session_untrack_id(struct lttng_session *session,
1681 enum tracker_type tracker_type, int id)
1682 {
1683 struct lttng_id_tracker *tracker;
1684 int ret;
1685
1686 tracker = get_tracker(session, tracker_type);
1687 if (!tracker)
1688 return -EINVAL;
1689 if (id < -1)
1690 return -EINVAL;
1691 mutex_lock(&sessions_mutex);
1692 if (id == -1) {
1693 /* untrack all ids: replace by empty tracker. */
1694 ret = lttng_id_tracker_empty_set(tracker);
1695 } else {
1696 ret = lttng_id_tracker_del(tracker, id);
1697 }
1698 mutex_unlock(&sessions_mutex);
1699 return ret;
1700 }
1701
1702 static
1703 void *id_list_start(struct seq_file *m, loff_t *pos)
1704 {
1705 struct lttng_id_tracker *id_tracker = m->private;
1706 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1707 struct lttng_id_hash_node *e;
1708 int iter = 0, i;
1709
1710 mutex_lock(&sessions_mutex);
1711 if (id_tracker_p) {
1712 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1713 struct hlist_head *head = &id_tracker_p->id_hash[i];
1714
1715 lttng_hlist_for_each_entry(e, head, hlist) {
1716 if (iter++ >= *pos)
1717 return e;
1718 }
1719 }
1720 } else {
1721 /* ID tracker disabled. */
1722 if (iter >= *pos && iter == 0) {
1723 return id_tracker_p; /* empty tracker */
1724 }
1725 iter++;
1726 }
1727 /* End of list */
1728 return NULL;
1729 }
1730
1731 /* Called with sessions_mutex held. */
1732 static
1733 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1734 {
1735 struct lttng_id_tracker *id_tracker = m->private;
1736 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1737 struct lttng_id_hash_node *e;
1738 int iter = 0, i;
1739
1740 (*ppos)++;
1741 if (id_tracker_p) {
1742 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1743 struct hlist_head *head = &id_tracker_p->id_hash[i];
1744
1745 lttng_hlist_for_each_entry(e, head, hlist) {
1746 if (iter++ >= *ppos)
1747 return e;
1748 }
1749 }
1750 } else {
1751 /* ID tracker disabled. */
1752 if (iter >= *ppos && iter == 0)
1753 return p; /* empty tracker */
1754 iter++;
1755 }
1756
1757 /* End of list */
1758 return NULL;
1759 }
1760
1761 static
1762 void id_list_stop(struct seq_file *m, void *p)
1763 {
1764 mutex_unlock(&sessions_mutex);
1765 }
1766
1767 static
1768 int id_list_show(struct seq_file *m, void *p)
1769 {
1770 struct lttng_id_tracker *id_tracker = m->private;
1771 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1772 int id;
1773
1774 if (p == id_tracker_p) {
1775 /* Tracker disabled. */
1776 id = -1;
1777 } else {
1778 const struct lttng_id_hash_node *e = p;
1779
1780 id = lttng_id_tracker_get_node_id(e);
1781 }
1782 switch (id_tracker->tracker_type) {
1783 case TRACKER_PID:
1784 seq_printf(m, "process { pid = %d; };\n", id);
1785 break;
1786 case TRACKER_VPID:
1787 seq_printf(m, "process { vpid = %d; };\n", id);
1788 break;
1789 case TRACKER_UID:
1790 seq_printf(m, "user { uid = %d; };\n", id);
1791 break;
1792 case TRACKER_VUID:
1793 seq_printf(m, "user { vuid = %d; };\n", id);
1794 break;
1795 case TRACKER_GID:
1796 seq_printf(m, "group { gid = %d; };\n", id);
1797 break;
1798 case TRACKER_VGID:
1799 seq_printf(m, "group { vgid = %d; };\n", id);
1800 break;
1801 default:
1802 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1803 }
1804 return 0;
1805 }
1806
1807 static
1808 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1809 .start = id_list_start,
1810 .next = id_list_next,
1811 .stop = id_list_stop,
1812 .show = id_list_show,
1813 };
1814
1815 static
1816 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1817 {
1818 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1819 }
1820
1821 static
1822 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1823 {
1824 struct seq_file *m = file->private_data;
1825 struct lttng_id_tracker *id_tracker = m->private;
1826 int ret;
1827
1828 WARN_ON_ONCE(!id_tracker);
1829 ret = seq_release(inode, file);
1830 if (!ret)
1831 fput(id_tracker->session->file);
1832 return ret;
1833 }
1834
1835 const struct file_operations lttng_tracker_ids_list_fops = {
1836 .owner = THIS_MODULE,
1837 .open = lttng_tracker_ids_list_open,
1838 .read = seq_read,
1839 .llseek = seq_lseek,
1840 .release = lttng_tracker_ids_list_release,
1841 };
1842
1843 int lttng_session_list_tracker_ids(struct lttng_session *session,
1844 enum tracker_type tracker_type)
1845 {
1846 struct file *tracker_ids_list_file;
1847 struct seq_file *m;
1848 int file_fd, ret;
1849
1850 file_fd = lttng_get_unused_fd();
1851 if (file_fd < 0) {
1852 ret = file_fd;
1853 goto fd_error;
1854 }
1855
1856 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1857 &lttng_tracker_ids_list_fops,
1858 NULL, O_RDWR);
1859 if (IS_ERR(tracker_ids_list_file)) {
1860 ret = PTR_ERR(tracker_ids_list_file);
1861 goto file_error;
1862 }
1863 if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
1864 ret = -EOVERFLOW;
1865 goto refcount_error;
1866 }
1867 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1868 if (ret < 0)
1869 goto open_error;
1870 m = tracker_ids_list_file->private_data;
1871
1872 m->private = get_tracker(session, tracker_type);
1873 BUG_ON(!m->private);
1874 fd_install(file_fd, tracker_ids_list_file);
1875
1876 return file_fd;
1877
1878 open_error:
1879 atomic_long_dec(&session->file->f_count);
1880 refcount_error:
1881 fput(tracker_ids_list_file);
1882 file_error:
1883 put_unused_fd(file_fd);
1884 fd_error:
1885 return ret;
1886 }
1887
1888 /*
1889 * Enabler management.
1890 */
1891 static
1892 int lttng_match_enabler_star_glob(const char *desc_name,
1893 const char *pattern)
1894 {
1895 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1896 desc_name, LTTNG_SIZE_MAX))
1897 return 0;
1898 return 1;
1899 }
1900
1901 static
1902 int lttng_match_enabler_name(const char *desc_name,
1903 const char *name)
1904 {
1905 if (strcmp(desc_name, name))
1906 return 0;
1907 return 1;
1908 }
1909
1910 int lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
1911 struct lttng_enabler *enabler)
1912 {
1913 const char *desc_name, *enabler_name;
1914 bool compat = false, entry = false;
1915
1916 enabler_name = enabler->event_param.name;
1917 switch (enabler->event_param.instrumentation) {
1918 case LTTNG_KERNEL_ABI_TRACEPOINT:
1919 desc_name = desc->event_name;
1920 switch (enabler->format_type) {
1921 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1922 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1923 case LTTNG_ENABLER_FORMAT_NAME:
1924 return lttng_match_enabler_name(desc_name, enabler_name);
1925 default:
1926 return -EINVAL;
1927 }
1928 break;
1929
1930 case LTTNG_KERNEL_ABI_SYSCALL:
1931 desc_name = desc->event_name;
1932 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1933 desc_name += strlen("compat_");
1934 compat = true;
1935 }
1936 if (!strncmp(desc_name, "syscall_exit_",
1937 strlen("syscall_exit_"))) {
1938 desc_name += strlen("syscall_exit_");
1939 } else if (!strncmp(desc_name, "syscall_entry_",
1940 strlen("syscall_entry_"))) {
1941 desc_name += strlen("syscall_entry_");
1942 entry = true;
1943 } else {
1944 WARN_ON_ONCE(1);
1945 return -EINVAL;
1946 }
1947 switch (enabler->event_param.u.syscall.entryexit) {
1948 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1949 break;
1950 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1951 if (!entry)
1952 return 0;
1953 break;
1954 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1955 if (entry)
1956 return 0;
1957 break;
1958 default:
1959 return -EINVAL;
1960 }
1961 switch (enabler->event_param.u.syscall.abi) {
1962 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1963 break;
1964 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1965 if (compat)
1966 return 0;
1967 break;
1968 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1969 if (!compat)
1970 return 0;
1971 break;
1972 default:
1973 return -EINVAL;
1974 }
1975 switch (enabler->event_param.u.syscall.match) {
1976 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
1977 switch (enabler->format_type) {
1978 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1979 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1980 case LTTNG_ENABLER_FORMAT_NAME:
1981 return lttng_match_enabler_name(desc_name, enabler_name);
1982 default:
1983 return -EINVAL;
1984 }
1985 break;
1986 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
1987 return -EINVAL; /* Not implemented. */
1988 default:
1989 return -EINVAL;
1990 }
1991 break;
1992
1993 default:
1994 WARN_ON_ONCE(1);
1995 return -EINVAL;
1996 }
1997 }
1998
1999 static
2000 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
2001 struct lttng_kernel_event_recorder *event_recorder)
2002 {
2003 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
2004 event_enabler);
2005
2006 if (base_enabler->event_param.instrumentation != event_recorder->priv->parent.instrumentation)
2007 return 0;
2008 if (lttng_desc_match_enabler(event_recorder->priv->parent.desc, base_enabler)
2009 && event_recorder->chan == event_enabler->chan)
2010 return 1;
2011 else
2012 return 0;
2013 }
2014
2015 static
2016 int lttng_event_notifier_enabler_match_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler,
2017 struct lttng_kernel_event_notifier *event_notifier)
2018 {
2019 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(
2020 event_notifier_enabler);
2021
2022 if (base_enabler->event_param.instrumentation != event_notifier->priv->parent.instrumentation)
2023 return 0;
2024 if (lttng_desc_match_enabler(event_notifier->priv->parent.desc, base_enabler)
2025 && event_notifier->priv->group == event_notifier_enabler->group
2026 && event_notifier->priv->parent.user_token == event_notifier_enabler->base.user_token)
2027 return 1;
2028 else
2029 return 0;
2030 }
2031
2032 static
2033 struct lttng_enabler_ref *lttng_enabler_ref(
2034 struct list_head *enablers_ref_list,
2035 struct lttng_enabler *enabler)
2036 {
2037 struct lttng_enabler_ref *enabler_ref;
2038
2039 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2040 if (enabler_ref->ref == enabler)
2041 return enabler_ref;
2042 }
2043 return NULL;
2044 }
2045
2046 static
2047 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
2048 {
2049 struct lttng_session *session = event_enabler->chan->session;
2050 struct lttng_kernel_probe_desc *probe_desc;
2051 const struct lttng_kernel_event_desc *desc;
2052 int i;
2053 struct list_head *probe_list;
2054
2055 probe_list = lttng_get_probe_list_head();
2056 /*
2057 * For each probe event, if we find that a probe event matches
2058 * our enabler, create an associated lttng_event if not
2059 * already present.
2060 */
2061 list_for_each_entry(probe_desc, probe_list, head) {
2062 for (i = 0; i < probe_desc->nr_events; i++) {
2063 int found = 0;
2064 struct hlist_head *head;
2065 struct lttng_kernel_event_recorder_private *event_recorder_private;
2066 struct lttng_kernel_event_recorder *event_recorder;
2067
2068 desc = probe_desc->event_desc[i];
2069 if (!lttng_desc_match_enabler(desc,
2070 lttng_event_enabler_as_enabler(event_enabler)))
2071 continue;
2072
2073 /*
2074 * Check if already created.
2075 */
2076 head = utils_borrow_hash_table_bucket(
2077 session->events_ht.table, LTTNG_EVENT_HT_SIZE,
2078 desc->event_name);
2079 lttng_hlist_for_each_entry(event_recorder_private, head, hlist) {
2080 if (event_recorder_private->parent.desc == desc
2081 && event_recorder_private->pub->chan == event_enabler->chan)
2082 found = 1;
2083 }
2084 if (found)
2085 continue;
2086
2087 /*
2088 * We need to create an event for this
2089 * event probe.
2090 */
2091 event_recorder = _lttng_kernel_event_recorder_create(event_enabler->chan,
2092 NULL, desc, LTTNG_KERNEL_ABI_TRACEPOINT);
2093 if (!event_recorder) {
2094 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2095 probe_desc->event_desc[i]->event_name);
2096 }
2097 }
2098 }
2099 }
2100
2101 static
2102 void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2103 {
2104 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2105 struct lttng_kernel_probe_desc *probe_desc;
2106 const struct lttng_kernel_event_desc *desc;
2107 int i;
2108 struct list_head *probe_list;
2109
2110 probe_list = lttng_get_probe_list_head();
2111 /*
2112 * For each probe event, if we find that a probe event matches
2113 * our enabler, create an associated lttng_event_notifier if not
2114 * already present.
2115 */
2116 list_for_each_entry(probe_desc, probe_list, head) {
2117 for (i = 0; i < probe_desc->nr_events; i++) {
2118 int found = 0;
2119 struct hlist_head *head;
2120 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2121 struct lttng_kernel_event_notifier *event_notifier;
2122
2123 desc = probe_desc->event_desc[i];
2124 if (!lttng_desc_match_enabler(desc,
2125 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
2126 continue;
2127
2128 /*
2129 * Check if already created.
2130 */
2131 head = utils_borrow_hash_table_bucket(
2132 event_notifier_group->event_notifiers_ht.table,
2133 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->event_name);
2134 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
2135 if (event_notifier_priv->parent.desc == desc
2136 && event_notifier_priv->parent.user_token == event_notifier_enabler->base.user_token)
2137 found = 1;
2138 }
2139 if (found)
2140 continue;
2141
2142 /*
2143 * We need to create a event_notifier for this event probe.
2144 */
2145 event_notifier = _lttng_event_notifier_create(desc,
2146 event_notifier_enabler->base.user_token,
2147 event_notifier_enabler->error_counter_index,
2148 event_notifier_group, NULL,
2149 LTTNG_KERNEL_ABI_TRACEPOINT);
2150 if (IS_ERR(event_notifier)) {
2151 printk(KERN_INFO "Unable to create event_notifier %s\n",
2152 probe_desc->event_desc[i]->event_name);
2153 }
2154 }
2155 }
2156 }
2157
2158 static
2159 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
2160 {
2161 int ret;
2162
2163 ret = lttng_syscalls_register_event(event_enabler);
2164 WARN_ON_ONCE(ret);
2165 }
2166
2167 static
2168 void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2169 {
2170 int ret;
2171
2172 ret = lttng_syscalls_register_event_notifier(event_notifier_enabler);
2173 WARN_ON_ONCE(ret);
2174 ret = lttng_syscalls_create_matching_event_notifiers(event_notifier_enabler);
2175 WARN_ON_ONCE(ret);
2176 }
2177
2178 /*
2179 * Create struct lttng_kernel_event_recorder if it is missing and present in the list of
2180 * tracepoint probes.
2181 * Should be called with sessions mutex held.
2182 */
2183 static
2184 void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
2185 {
2186 switch (event_enabler->base.event_param.instrumentation) {
2187 case LTTNG_KERNEL_ABI_TRACEPOINT:
2188 lttng_create_tracepoint_event_if_missing(event_enabler);
2189 break;
2190
2191 case LTTNG_KERNEL_ABI_SYSCALL:
2192 lttng_create_syscall_event_if_missing(event_enabler);
2193 break;
2194
2195 default:
2196 WARN_ON_ONCE(1);
2197 break;
2198 }
2199 }
2200
2201 /*
2202 * Create events associated with an event_enabler (if not already present),
2203 * and add backward reference from the event to the enabler.
2204 * Should be called with sessions mutex held.
2205 */
2206 static
2207 int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
2208 {
2209 struct lttng_channel *chan = event_enabler->chan;
2210 struct lttng_session *session = event_enabler->chan->session;
2211 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
2212 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2213
2214 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2215 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2216 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2217 !strcmp(base_enabler->event_param.name, "*")) {
2218 int enabled = base_enabler->enabled;
2219 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2220
2221 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2222 WRITE_ONCE(chan->syscall_all_entry, enabled);
2223
2224 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2225 WRITE_ONCE(chan->syscall_all_exit, enabled);
2226 }
2227
2228 /* First ensure that probe events are created for this enabler. */
2229 lttng_create_event_if_missing(event_enabler);
2230
2231 /* For each event matching event_enabler in session event list. */
2232 list_for_each_entry(event_recorder_priv, &session->events, node) {
2233 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2234 struct lttng_enabler_ref *enabler_ref;
2235
2236 if (!lttng_event_enabler_match_event(event_enabler, event_recorder))
2237 continue;
2238 enabler_ref = lttng_enabler_ref(&event_recorder_priv->parent.enablers_ref_head,
2239 lttng_event_enabler_as_enabler(event_enabler));
2240 if (!enabler_ref) {
2241 /*
2242 * If no backward ref, create it.
2243 * Add backward ref from event to event_enabler.
2244 */
2245 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2246 if (!enabler_ref)
2247 return -ENOMEM;
2248 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
2249 list_add(&enabler_ref->node,
2250 &event_recorder_priv->parent.enablers_ref_head);
2251 }
2252
2253 /*
2254 * Link filter bytecodes if not linked yet.
2255 */
2256 lttng_enabler_link_bytecode(event_recorder_priv->parent.desc,
2257 lttng_static_ctx,
2258 &event_recorder_priv->parent.filter_bytecode_runtime_head,
2259 &lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
2260 }
2261 return 0;
2262 }
2263
2264 /*
2265 * Create struct lttng_kernel_event_notifier if it is missing and present in the list of
2266 * tracepoint probes.
2267 * Should be called with sessions mutex held.
2268 */
2269 static
2270 void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2271 {
2272 switch (event_notifier_enabler->base.event_param.instrumentation) {
2273 case LTTNG_KERNEL_ABI_TRACEPOINT:
2274 lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
2275 break;
2276
2277 case LTTNG_KERNEL_ABI_SYSCALL:
2278 lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler);
2279 break;
2280
2281 default:
2282 WARN_ON_ONCE(1);
2283 break;
2284 }
2285 }
2286
2287 /*
2288 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2289 */
2290 static
2291 int lttng_event_notifier_enabler_ref_event_notifiers(
2292 struct lttng_event_notifier_enabler *event_notifier_enabler)
2293 {
2294 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2295 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2296 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2297
2298 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2299 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2300 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2301 !strcmp(base_enabler->event_param.name, "*")) {
2302
2303 int enabled = base_enabler->enabled;
2304 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2305
2306 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2307 WRITE_ONCE(event_notifier_group->syscall_all_entry, enabled);
2308
2309 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2310 WRITE_ONCE(event_notifier_group->syscall_all_exit, enabled);
2311
2312 }
2313
2314 /* First ensure that probe event_notifiers are created for this enabler. */
2315 lttng_create_event_notifier_if_missing(event_notifier_enabler);
2316
2317 /* Link the created event_notifier with its associated enabler. */
2318 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2319 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2320 struct lttng_enabler_ref *enabler_ref;
2321
2322 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier))
2323 continue;
2324
2325 enabler_ref = lttng_enabler_ref(&event_notifier_priv->parent.enablers_ref_head,
2326 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2327 if (!enabler_ref) {
2328 /*
2329 * If no backward ref, create it.
2330 * Add backward ref from event_notifier to enabler.
2331 */
2332 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2333 if (!enabler_ref)
2334 return -ENOMEM;
2335
2336 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2337 event_notifier_enabler);
2338 list_add(&enabler_ref->node,
2339 &event_notifier_priv->parent.enablers_ref_head);
2340 }
2341
2342 /*
2343 * Link filter bytecodes if not linked yet.
2344 */
2345 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2346 lttng_static_ctx, &event_notifier_priv->parent.filter_bytecode_runtime_head,
2347 &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
2348
2349 /* Link capture bytecodes if not linked yet. */
2350 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2351 lttng_static_ctx, &event_notifier_priv->capture_bytecode_runtime_head,
2352 &event_notifier_enabler->capture_bytecode_head);
2353
2354 event_notifier_priv->num_captures = event_notifier_enabler->num_captures;
2355 }
2356 return 0;
2357 }
2358
2359 /*
2360 * Called at module load: connect the probe on all enablers matching
2361 * this event.
2362 * Called with sessions lock held.
2363 */
2364 int lttng_fix_pending_events(void)
2365 {
2366 struct lttng_session *session;
2367
2368 list_for_each_entry(session, &sessions, list)
2369 lttng_session_lazy_sync_event_enablers(session);
2370 return 0;
2371 }
2372
2373 static bool lttng_event_notifier_group_has_active_event_notifiers(
2374 struct lttng_event_notifier_group *event_notifier_group)
2375 {
2376 struct lttng_event_notifier_enabler *event_notifier_enabler;
2377
2378 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2379 node) {
2380 if (event_notifier_enabler->base.enabled)
2381 return true;
2382 }
2383 return false;
2384 }
2385
2386 bool lttng_event_notifier_active(void)
2387 {
2388 struct lttng_event_notifier_group *event_notifier_group;
2389
2390 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2391 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2392 return true;
2393 }
2394 return false;
2395 }
2396
2397 int lttng_fix_pending_event_notifiers(void)
2398 {
2399 struct lttng_event_notifier_group *event_notifier_group;
2400
2401 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2402 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2403 return 0;
2404 }
2405
2406 struct lttng_event_enabler *lttng_event_enabler_create(
2407 enum lttng_enabler_format_type format_type,
2408 struct lttng_kernel_abi_event *event_param,
2409 struct lttng_channel *chan)
2410 {
2411 struct lttng_event_enabler *event_enabler;
2412
2413 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2414 if (!event_enabler)
2415 return NULL;
2416 event_enabler->base.format_type = format_type;
2417 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2418 memcpy(&event_enabler->base.event_param, event_param,
2419 sizeof(event_enabler->base.event_param));
2420 event_enabler->chan = chan;
2421 /* ctx left NULL */
2422 event_enabler->base.enabled = 0;
2423 mutex_lock(&sessions_mutex);
2424 list_add(&event_enabler->node, &event_enabler->chan->session->enablers_head);
2425 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2426 mutex_unlock(&sessions_mutex);
2427 return event_enabler;
2428 }
2429
2430 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2431 {
2432 mutex_lock(&sessions_mutex);
2433 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2434 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2435 mutex_unlock(&sessions_mutex);
2436 return 0;
2437 }
2438
2439 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2440 {
2441 mutex_lock(&sessions_mutex);
2442 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2443 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2444 mutex_unlock(&sessions_mutex);
2445 return 0;
2446 }
2447
2448 static
2449 int lttng_enabler_attach_filter_bytecode(struct lttng_enabler *enabler,
2450 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2451 {
2452 struct lttng_kernel_bytecode_node *bytecode_node;
2453 uint32_t bytecode_len;
2454 int ret;
2455
2456 ret = get_user(bytecode_len, &bytecode->len);
2457 if (ret)
2458 return ret;
2459 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2460 GFP_KERNEL);
2461 if (!bytecode_node)
2462 return -ENOMEM;
2463 ret = copy_from_user(&bytecode_node->bc, bytecode,
2464 sizeof(*bytecode) + bytecode_len);
2465 if (ret)
2466 goto error_free;
2467
2468 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2469 bytecode_node->enabler = enabler;
2470 /* Enforce length based on allocated size */
2471 bytecode_node->bc.len = bytecode_len;
2472 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2473
2474 return 0;
2475
2476 error_free:
2477 lttng_kvfree(bytecode_node);
2478 return ret;
2479 }
2480
2481 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler *event_enabler,
2482 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2483 {
2484 int ret;
2485 ret = lttng_enabler_attach_filter_bytecode(
2486 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2487 if (ret)
2488 goto error;
2489
2490 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2491 return 0;
2492
2493 error:
2494 return ret;
2495 }
2496
2497 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2498 struct lttng_kernel_abi_event_callsite __user *callsite)
2499 {
2500
2501 switch (event->priv->instrumentation) {
2502 case LTTNG_KERNEL_ABI_UPROBE:
2503 return lttng_uprobes_event_add_callsite(event, callsite);
2504 default:
2505 return -EINVAL;
2506 }
2507 }
2508
2509 static
2510 void lttng_enabler_destroy(struct lttng_enabler *enabler)
2511 {
2512 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2513
2514 /* Destroy filter bytecode */
2515 list_for_each_entry_safe(filter_node, tmp_filter_node,
2516 &enabler->filter_bytecode_head, node) {
2517 lttng_kvfree(filter_node);
2518 }
2519 }
2520
2521 static
2522 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2523 {
2524 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2525
2526 list_del(&event_enabler->node);
2527 kfree(event_enabler);
2528 }
2529
2530 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2531 struct lttng_event_notifier_group *event_notifier_group,
2532 enum lttng_enabler_format_type format_type,
2533 struct lttng_kernel_abi_event_notifier *event_notifier_param)
2534 {
2535 struct lttng_event_notifier_enabler *event_notifier_enabler;
2536
2537 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2538 if (!event_notifier_enabler)
2539 return NULL;
2540
2541 event_notifier_enabler->base.format_type = format_type;
2542 INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
2543 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2544
2545 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2546 event_notifier_enabler->num_captures = 0;
2547
2548 memcpy(&event_notifier_enabler->base.event_param, &event_notifier_param->event,
2549 sizeof(event_notifier_enabler->base.event_param));
2550
2551 event_notifier_enabler->base.enabled = 0;
2552 event_notifier_enabler->base.user_token = event_notifier_param->event.token;
2553 event_notifier_enabler->group = event_notifier_group;
2554
2555 mutex_lock(&sessions_mutex);
2556 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2557 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2558
2559 mutex_unlock(&sessions_mutex);
2560
2561 return event_notifier_enabler;
2562 }
2563
2564 int lttng_event_notifier_enabler_enable(
2565 struct lttng_event_notifier_enabler *event_notifier_enabler)
2566 {
2567 mutex_lock(&sessions_mutex);
2568 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2569 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2570 mutex_unlock(&sessions_mutex);
2571 return 0;
2572 }
2573
2574 int lttng_event_notifier_enabler_disable(
2575 struct lttng_event_notifier_enabler *event_notifier_enabler)
2576 {
2577 mutex_lock(&sessions_mutex);
2578 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2579 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2580 mutex_unlock(&sessions_mutex);
2581 return 0;
2582 }
2583
2584 int lttng_event_notifier_enabler_attach_filter_bytecode(
2585 struct lttng_event_notifier_enabler *event_notifier_enabler,
2586 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2587 {
2588 int ret;
2589
2590 ret = lttng_enabler_attach_filter_bytecode(
2591 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
2592 bytecode);
2593 if (ret)
2594 goto error;
2595
2596 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2597 return 0;
2598
2599 error:
2600 return ret;
2601 }
2602
2603 int lttng_event_notifier_enabler_attach_capture_bytecode(
2604 struct lttng_event_notifier_enabler *event_notifier_enabler,
2605 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2606 {
2607 struct lttng_kernel_bytecode_node *bytecode_node;
2608 struct lttng_enabler *enabler =
2609 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2610 uint32_t bytecode_len;
2611 int ret;
2612
2613 ret = get_user(bytecode_len, &bytecode->len);
2614 if (ret)
2615 return ret;
2616
2617 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2618 GFP_KERNEL);
2619 if (!bytecode_node)
2620 return -ENOMEM;
2621
2622 ret = copy_from_user(&bytecode_node->bc, bytecode,
2623 sizeof(*bytecode) + bytecode_len);
2624 if (ret)
2625 goto error_free;
2626
2627 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2628 bytecode_node->enabler = enabler;
2629
2630 /* Enforce length based on allocated size */
2631 bytecode_node->bc.len = bytecode_len;
2632 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2633
2634 event_notifier_enabler->num_captures++;
2635
2636 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2637 goto end;
2638
2639 error_free:
2640 lttng_kvfree(bytecode_node);
2641 end:
2642 return ret;
2643 }
2644
2645 static
2646 void lttng_event_notifier_enabler_destroy(
2647 struct lttng_event_notifier_enabler *event_notifier_enabler)
2648 {
2649 if (!event_notifier_enabler) {
2650 return;
2651 }
2652
2653 list_del(&event_notifier_enabler->node);
2654
2655 lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2656 kfree(event_notifier_enabler);
2657 }
2658
2659 /*
2660 * lttng_session_sync_event_enablers should be called just before starting a
2661 * session.
2662 * Should be called with sessions mutex held.
2663 */
2664 static
2665 void lttng_session_sync_event_enablers(struct lttng_session *session)
2666 {
2667 struct lttng_event_enabler *event_enabler;
2668 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2669
2670 list_for_each_entry(event_enabler, &session->enablers_head, node)
2671 lttng_event_enabler_ref_events(event_enabler);
2672 /*
2673 * For each event, if at least one of its enablers is enabled,
2674 * and its channel and session transient states are enabled, we
2675 * enable the event, else we disable it.
2676 */
2677 list_for_each_entry(event_recorder_priv, &session->events, node) {
2678 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2679 struct lttng_enabler_ref *enabler_ref;
2680 struct lttng_kernel_bytecode_runtime *runtime;
2681 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2682 int nr_filters = 0;
2683
2684 switch (event_recorder_priv->parent.instrumentation) {
2685 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
2686 case LTTNG_KERNEL_ABI_SYSCALL:
2687 /* Enable events */
2688 list_for_each_entry(enabler_ref,
2689 &event_recorder_priv->parent.enablers_ref_head, node) {
2690 if (enabler_ref->ref->enabled) {
2691 enabled = 1;
2692 break;
2693 }
2694 }
2695 break;
2696
2697 default:
2698 /* Not handled with lazy sync. */
2699 continue;
2700 }
2701 /*
2702 * Enabled state is based on union of enablers, with
2703 * intesection of session and channel transient enable
2704 * states.
2705 */
2706 enabled = enabled && session->tstate && event_recorder->chan->tstate;
2707
2708 WRITE_ONCE(event_recorder->parent.enabled, enabled);
2709 /*
2710 * Sync tracepoint registration with event enabled
2711 * state.
2712 */
2713 if (enabled) {
2714 register_event(event_recorder);
2715 } else {
2716 _lttng_event_unregister(event_recorder);
2717 }
2718
2719 /* Check if has enablers without bytecode enabled */
2720 list_for_each_entry(enabler_ref,
2721 &event_recorder_priv->parent.enablers_ref_head, node) {
2722 if (enabler_ref->ref->enabled
2723 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2724 has_enablers_without_filter_bytecode = 1;
2725 break;
2726 }
2727 }
2728 event_recorder_priv->parent.has_enablers_without_filter_bytecode =
2729 has_enablers_without_filter_bytecode;
2730
2731 /* Enable filters */
2732 list_for_each_entry(runtime,
2733 &event_recorder_priv->parent.filter_bytecode_runtime_head, node) {
2734 lttng_bytecode_sync_state(runtime);
2735 nr_filters++;
2736 }
2737 WRITE_ONCE(event_recorder_priv->parent.pub->eval_filter,
2738 !(has_enablers_without_filter_bytecode || !nr_filters));
2739 }
2740 }
2741
2742 /*
2743 * Apply enablers to session events, adding events to session if need
2744 * be. It is required after each modification applied to an active
2745 * session, and right before session "start".
2746 * "lazy" sync means we only sync if required.
2747 * Should be called with sessions mutex held.
2748 */
2749 static
2750 void lttng_session_lazy_sync_event_enablers(struct lttng_session *session)
2751 {
2752 /* We can skip if session is not active */
2753 if (!session->active)
2754 return;
2755 lttng_session_sync_event_enablers(session);
2756 }
2757
2758 static
2759 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2760 {
2761 struct lttng_event_notifier_enabler *event_notifier_enabler;
2762 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2763
2764 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2765 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2766
2767 /*
2768 * For each event_notifier, if at least one of its enablers is enabled,
2769 * we enable the event_notifier, else we disable it.
2770 */
2771 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2772 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2773 struct lttng_enabler_ref *enabler_ref;
2774 struct lttng_kernel_bytecode_runtime *runtime;
2775 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2776 int nr_filters = 0, nr_captures = 0;
2777
2778 switch (event_notifier_priv->parent.instrumentation) {
2779 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
2780 case LTTNG_KERNEL_ABI_SYSCALL:
2781 /* Enable event_notifiers */
2782 list_for_each_entry(enabler_ref,
2783 &event_notifier_priv->parent.enablers_ref_head, node) {
2784 if (enabler_ref->ref->enabled) {
2785 enabled = 1;
2786 break;
2787 }
2788 }
2789 break;
2790
2791 default:
2792 /* Not handled with sync. */
2793 continue;
2794 }
2795
2796 WRITE_ONCE(event_notifier->parent.enabled, enabled);
2797 /*
2798 * Sync tracepoint registration with event_notifier enabled
2799 * state.
2800 */
2801 if (enabled) {
2802 if (!event_notifier_priv->parent.registered)
2803 register_event_notifier(event_notifier);
2804 } else {
2805 if (event_notifier_priv->parent.registered)
2806 _lttng_event_notifier_unregister(event_notifier);
2807 }
2808
2809 /* Check if has enablers without bytecode enabled */
2810 list_for_each_entry(enabler_ref,
2811 &event_notifier_priv->parent.enablers_ref_head, node) {
2812 if (enabler_ref->ref->enabled
2813 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2814 has_enablers_without_filter_bytecode = 1;
2815 break;
2816 }
2817 }
2818 event_notifier_priv->parent.has_enablers_without_filter_bytecode =
2819 has_enablers_without_filter_bytecode;
2820
2821 /* Enable filters */
2822 list_for_each_entry(runtime,
2823 &event_notifier_priv->parent.filter_bytecode_runtime_head, node) {
2824 lttng_bytecode_sync_state(runtime);
2825 nr_filters++;
2826 }
2827 WRITE_ONCE(event_notifier_priv->parent.pub->eval_filter,
2828 !(has_enablers_without_filter_bytecode || !nr_filters));
2829
2830 /* Enable captures */
2831 list_for_each_entry(runtime,
2832 &event_notifier_priv->capture_bytecode_runtime_head, node) {
2833 lttng_bytecode_sync_state(runtime);
2834 nr_captures++;
2835 }
2836 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2837 }
2838 }
2839
2840 /*
2841 * Serialize at most one packet worth of metadata into a metadata
2842 * channel.
2843 * We grab the metadata cache mutex to get exclusive access to our metadata
2844 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2845 * allows us to do racy operations such as looking for remaining space left in
2846 * packet and write, since mutual exclusion protects us from concurrent writes.
2847 * Mutual exclusion on the metadata cache allow us to read the cache content
2848 * without racing against reallocation of the cache by updates.
2849 * Returns the number of bytes written in the channel, 0 if no data
2850 * was written and a negative value on error.
2851 */
2852 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2853 struct channel *chan, bool *coherent)
2854 {
2855 struct lttng_kernel_ring_buffer_ctx ctx;
2856 int ret = 0;
2857 size_t len, reserve_len;
2858
2859 /*
2860 * Ensure we support mutiple get_next / put sequences followed by
2861 * put_next. The metadata cache lock protects reading the metadata
2862 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2863 * "flush" operations on the buffer invoked by different processes.
2864 * Moreover, since the metadata cache memory can be reallocated, we
2865 * need to have exclusive access against updates even though we only
2866 * read it.
2867 */
2868 mutex_lock(&stream->metadata_cache->lock);
2869 WARN_ON(stream->metadata_in < stream->metadata_out);
2870 if (stream->metadata_in != stream->metadata_out)
2871 goto end;
2872
2873 /* Metadata regenerated, change the version. */
2874 if (stream->metadata_cache->version != stream->version)
2875 stream->version = stream->metadata_cache->version;
2876
2877 len = stream->metadata_cache->metadata_written -
2878 stream->metadata_in;
2879 if (!len)
2880 goto end;
2881 reserve_len = min_t(size_t,
2882 stream->transport->ops.priv->packet_avail_size(chan),
2883 len);
2884 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2885 sizeof(char), NULL);
2886 /*
2887 * If reservation failed, return an error to the caller.
2888 */
2889 ret = stream->transport->ops.event_reserve(&ctx);
2890 if (ret != 0) {
2891 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2892 stream->coherent = false;
2893 goto end;
2894 }
2895 stream->transport->ops.event_write(&ctx,
2896 stream->metadata_cache->data + stream->metadata_in,
2897 reserve_len);
2898 stream->transport->ops.event_commit(&ctx);
2899 stream->metadata_in += reserve_len;
2900 if (reserve_len < len)
2901 stream->coherent = false;
2902 else
2903 stream->coherent = true;
2904 ret = reserve_len;
2905
2906 end:
2907 if (coherent)
2908 *coherent = stream->coherent;
2909 mutex_unlock(&stream->metadata_cache->lock);
2910 return ret;
2911 }
2912
2913 static
2914 void lttng_metadata_begin(struct lttng_session *session)
2915 {
2916 if (atomic_inc_return(&session->metadata_cache->producing) == 1)
2917 mutex_lock(&session->metadata_cache->lock);
2918 }
2919
2920 static
2921 void lttng_metadata_end(struct lttng_session *session)
2922 {
2923 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2924 if (atomic_dec_return(&session->metadata_cache->producing) == 0) {
2925 struct lttng_metadata_stream *stream;
2926
2927 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
2928 wake_up_interruptible(&stream->read_wait);
2929 mutex_unlock(&session->metadata_cache->lock);
2930 }
2931 }
2932
2933 /*
2934 * Write the metadata to the metadata cache.
2935 * Must be called with sessions_mutex held.
2936 * The metadata cache lock protects us from concurrent read access from
2937 * thread outputting metadata content to ring buffer.
2938 * The content of the printf is printed as a single atomic metadata
2939 * transaction.
2940 */
2941 int lttng_metadata_printf(struct lttng_session *session,
2942 const char *fmt, ...)
2943 {
2944 char *str;
2945 size_t len;
2946 va_list ap;
2947
2948 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2949
2950 va_start(ap, fmt);
2951 str = kvasprintf(GFP_KERNEL, fmt, ap);
2952 va_end(ap);
2953 if (!str)
2954 return -ENOMEM;
2955
2956 len = strlen(str);
2957 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2958 if (session->metadata_cache->metadata_written + len >
2959 session->metadata_cache->cache_alloc) {
2960 char *tmp_cache_realloc;
2961 unsigned int tmp_cache_alloc_size;
2962
2963 tmp_cache_alloc_size = max_t(unsigned int,
2964 session->metadata_cache->cache_alloc + len,
2965 session->metadata_cache->cache_alloc << 1);
2966 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2967 if (!tmp_cache_realloc)
2968 goto err;
2969 if (session->metadata_cache->data) {
2970 memcpy(tmp_cache_realloc,
2971 session->metadata_cache->data,
2972 session->metadata_cache->cache_alloc);
2973 vfree(session->metadata_cache->data);
2974 }
2975
2976 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2977 session->metadata_cache->data = tmp_cache_realloc;
2978 }
2979 memcpy(session->metadata_cache->data +
2980 session->metadata_cache->metadata_written,
2981 str, len);
2982 session->metadata_cache->metadata_written += len;
2983 kfree(str);
2984
2985 return 0;
2986
2987 err:
2988 kfree(str);
2989 return -ENOMEM;
2990 }
2991
2992 static
2993 int print_tabs(struct lttng_session *session, size_t nesting)
2994 {
2995 size_t i;
2996
2997 for (i = 0; i < nesting; i++) {
2998 int ret;
2999
3000 ret = lttng_metadata_printf(session, " ");
3001 if (ret) {
3002 return ret;
3003 }
3004 }
3005 return 0;
3006 }
3007
3008 static
3009 int lttng_field_name_statedump(struct lttng_session *session,
3010 const struct lttng_kernel_event_field *field,
3011 size_t nesting)
3012 {
3013 return lttng_metadata_printf(session, " _%s;\n", field->name);
3014 }
3015
3016 static
3017 int _lttng_integer_type_statedump(struct lttng_session *session,
3018 const struct lttng_kernel_type_integer *type,
3019 enum lttng_kernel_string_encoding parent_encoding,
3020 size_t nesting)
3021 {
3022 int ret;
3023
3024 ret = print_tabs(session, nesting);
3025 if (ret)
3026 return ret;
3027 ret = lttng_metadata_printf(session,
3028 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
3029 type->size,
3030 type->alignment,
3031 type->signedness,
3032 (parent_encoding == lttng_kernel_string_encoding_none)
3033 ? "none"
3034 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
3035 ? "UTF8"
3036 : "ASCII",
3037 type->base,
3038 #if __BYTE_ORDER == __BIG_ENDIAN
3039 type->reverse_byte_order ? " byte_order = le;" : ""
3040 #else
3041 type->reverse_byte_order ? " byte_order = be;" : ""
3042 #endif
3043 );
3044 return ret;
3045 }
3046
3047 /*
3048 * Must be called with sessions_mutex held.
3049 */
3050 static
3051 int _lttng_struct_type_statedump(struct lttng_session *session,
3052 const struct lttng_kernel_type_struct *type,
3053 size_t nesting)
3054 {
3055 const char *prev_field_name = NULL;
3056 int ret;
3057 uint32_t i, nr_fields;
3058 unsigned int alignment;
3059
3060 ret = print_tabs(session, nesting);
3061 if (ret)
3062 return ret;
3063 ret = lttng_metadata_printf(session,
3064 "struct {\n");
3065 if (ret)
3066 return ret;
3067 nr_fields = type->nr_fields;
3068 for (i = 0; i < nr_fields; i++) {
3069 const struct lttng_kernel_event_field *iter_field;
3070
3071 iter_field = type->fields[i];
3072 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
3073 if (ret)
3074 return ret;
3075 }
3076 ret = print_tabs(session, nesting);
3077 if (ret)
3078 return ret;
3079 alignment = type->alignment;
3080 if (alignment) {
3081 ret = lttng_metadata_printf(session,
3082 "} align(%u)",
3083 alignment);
3084 } else {
3085 ret = lttng_metadata_printf(session,
3086 "}");
3087 }
3088 return ret;
3089 }
3090
3091 /*
3092 * Must be called with sessions_mutex held.
3093 */
3094 static
3095 int _lttng_struct_field_statedump(struct lttng_session *session,
3096 const struct lttng_kernel_event_field *field,
3097 size_t nesting)
3098 {
3099 int ret;
3100
3101 ret = _lttng_struct_type_statedump(session,
3102 lttng_kernel_get_type_struct(field->type), nesting);
3103 if (ret)
3104 return ret;
3105 return lttng_field_name_statedump(session, field, nesting);
3106 }
3107
3108 /*
3109 * Must be called with sessions_mutex held.
3110 */
3111 static
3112 int _lttng_variant_type_statedump(struct lttng_session *session,
3113 const struct lttng_kernel_type_variant *type,
3114 size_t nesting,
3115 const char *prev_field_name)
3116 {
3117 const char *tag_name;
3118 int ret;
3119 uint32_t i, nr_choices;
3120
3121 tag_name = type->tag_name;
3122 if (!tag_name)
3123 tag_name = prev_field_name;
3124 if (!tag_name)
3125 return -EINVAL;
3126 /*
3127 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3128 */
3129 if (type->alignment != 0)
3130 return -EINVAL;
3131 ret = print_tabs(session, nesting);
3132 if (ret)
3133 return ret;
3134 ret = lttng_metadata_printf(session,
3135 "variant <_%s> {\n",
3136 tag_name);
3137 if (ret)
3138 return ret;
3139 nr_choices = type->nr_choices;
3140 for (i = 0; i < nr_choices; i++) {
3141 const struct lttng_kernel_event_field *iter_field;
3142
3143 iter_field = type->choices[i];
3144 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3145 if (ret)
3146 return ret;
3147 }
3148 ret = print_tabs(session, nesting);
3149 if (ret)
3150 return ret;
3151 ret = lttng_metadata_printf(session,
3152 "}");
3153 return ret;
3154 }
3155
3156 /*
3157 * Must be called with sessions_mutex held.
3158 */
3159 static
3160 int _lttng_variant_field_statedump(struct lttng_session *session,
3161 const struct lttng_kernel_event_field *field,
3162 size_t nesting,
3163 const char *prev_field_name)
3164 {
3165 int ret;
3166
3167 ret = _lttng_variant_type_statedump(session,
3168 lttng_kernel_get_type_variant(field->type), nesting,
3169 prev_field_name);
3170 if (ret)
3171 return ret;
3172 return lttng_field_name_statedump(session, field, nesting);
3173 }
3174
3175 /*
3176 * Must be called with sessions_mutex held.
3177 */
3178 static
3179 int _lttng_array_field_statedump(struct lttng_session *session,
3180 const struct lttng_kernel_event_field *field,
3181 size_t nesting)
3182 {
3183 int ret;
3184 const struct lttng_kernel_type_array *array_type;
3185 const struct lttng_kernel_type_common *elem_type;
3186
3187 array_type = lttng_kernel_get_type_array(field->type);
3188 WARN_ON_ONCE(!array_type);
3189
3190 if (array_type->alignment) {
3191 ret = print_tabs(session, nesting);
3192 if (ret)
3193 return ret;
3194 ret = lttng_metadata_printf(session,
3195 "struct { } align(%u) _%s_padding;\n",
3196 array_type->alignment * CHAR_BIT,
3197 field->name);
3198 if (ret)
3199 return ret;
3200 }
3201 /*
3202 * Nested compound types: Only array of structures and variants are
3203 * currently supported.
3204 */
3205 elem_type = array_type->elem_type;
3206 switch (elem_type->type) {
3207 case lttng_kernel_type_integer:
3208 case lttng_kernel_type_struct:
3209 case lttng_kernel_type_variant:
3210 ret = _lttng_type_statedump(session, elem_type,
3211 array_type->encoding, nesting);
3212 if (ret)
3213 return ret;
3214 break;
3215
3216 default:
3217 return -EINVAL;
3218 }
3219 ret = lttng_metadata_printf(session,
3220 " _%s[%u];\n",
3221 field->name,
3222 array_type->length);
3223 return ret;
3224 }
3225
3226 /*
3227 * Must be called with sessions_mutex held.
3228 */
3229 static
3230 int _lttng_sequence_field_statedump(struct lttng_session *session,
3231 const struct lttng_kernel_event_field *field,
3232 size_t nesting,
3233 const char *prev_field_name)
3234 {
3235 int ret;
3236 const char *length_name;
3237 const struct lttng_kernel_type_sequence *sequence_type;
3238 const struct lttng_kernel_type_common *elem_type;
3239
3240 sequence_type = lttng_kernel_get_type_sequence(field->type);
3241 WARN_ON_ONCE(!sequence_type);
3242
3243 length_name = sequence_type->length_name;
3244 if (!length_name)
3245 length_name = prev_field_name;
3246 if (!length_name)
3247 return -EINVAL;
3248
3249 if (sequence_type->alignment) {
3250 ret = print_tabs(session, nesting);
3251 if (ret)
3252 return ret;
3253 ret = lttng_metadata_printf(session,
3254 "struct { } align(%u) _%s_padding;\n",
3255 sequence_type->alignment * CHAR_BIT,
3256 field->name);
3257 if (ret)
3258 return ret;
3259 }
3260
3261 /*
3262 * Nested compound types: Only array of structures and variants are
3263 * currently supported.
3264 */
3265 elem_type = sequence_type->elem_type;
3266 switch (elem_type->type) {
3267 case lttng_kernel_type_integer:
3268 case lttng_kernel_type_struct:
3269 case lttng_kernel_type_variant:
3270 ret = _lttng_type_statedump(session, elem_type,
3271 sequence_type->encoding, nesting);
3272 if (ret)
3273 return ret;
3274 break;
3275
3276 default:
3277 return -EINVAL;
3278 }
3279 ret = lttng_metadata_printf(session,
3280 " _%s[ _%s ];\n",
3281 field->name,
3282 length_name);
3283 return ret;
3284 }
3285
3286 /*
3287 * Must be called with sessions_mutex held.
3288 */
3289 static
3290 int _lttng_enum_type_statedump(struct lttng_session *session,
3291 const struct lttng_kernel_type_enum *type,
3292 size_t nesting)
3293 {
3294 const struct lttng_kernel_enum_desc *enum_desc;
3295 const struct lttng_kernel_type_common *container_type;
3296 int ret;
3297 unsigned int i, nr_entries;
3298
3299 container_type = type->container_type;
3300 if (container_type->type != lttng_kernel_type_integer) {
3301 ret = -EINVAL;
3302 goto end;
3303 }
3304 enum_desc = type->desc;
3305 nr_entries = enum_desc->nr_entries;
3306
3307 ret = print_tabs(session, nesting);
3308 if (ret)
3309 goto end;
3310 ret = lttng_metadata_printf(session, "enum : ");
3311 if (ret)
3312 goto end;
3313 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3314 lttng_kernel_string_encoding_none, 0);
3315 if (ret)
3316 goto end;
3317 ret = lttng_metadata_printf(session, " {\n");
3318 if (ret)
3319 goto end;
3320 /* Dump all entries */
3321 for (i = 0; i < nr_entries; i++) {
3322 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3323 int j, len;
3324
3325 ret = print_tabs(session, nesting + 1);
3326 if (ret)
3327 goto end;
3328 ret = lttng_metadata_printf(session,
3329 "\"");
3330 if (ret)
3331 goto end;
3332 len = strlen(entry->string);
3333 /* Escape the character '"' */
3334 for (j = 0; j < len; j++) {
3335 char c = entry->string[j];
3336
3337 switch (c) {
3338 case '"':
3339 ret = lttng_metadata_printf(session,
3340 "\\\"");
3341 break;
3342 case '\\':
3343 ret = lttng_metadata_printf(session,
3344 "\\\\");
3345 break;
3346 default:
3347 ret = lttng_metadata_printf(session,
3348 "%c", c);
3349 break;
3350 }
3351 if (ret)
3352 goto end;
3353 }
3354 ret = lttng_metadata_printf(session, "\"");
3355 if (ret)
3356 goto end;
3357
3358 if (entry->options.is_auto) {
3359 ret = lttng_metadata_printf(session, ",\n");
3360 if (ret)
3361 goto end;
3362 } else {
3363 ret = lttng_metadata_printf(session,
3364 " = ");
3365 if (ret)
3366 goto end;
3367 if (entry->start.signedness)
3368 ret = lttng_metadata_printf(session,
3369 "%lld", (long long) entry->start.value);
3370 else
3371 ret = lttng_metadata_printf(session,
3372 "%llu", entry->start.value);
3373 if (ret)
3374 goto end;
3375 if (entry->start.signedness == entry->end.signedness &&
3376 entry->start.value
3377 == entry->end.value) {
3378 ret = lttng_metadata_printf(session,
3379 ",\n");
3380 } else {
3381 if (entry->end.signedness) {
3382 ret = lttng_metadata_printf(session,
3383 " ... %lld,\n",
3384 (long long) entry->end.value);
3385 } else {
3386 ret = lttng_metadata_printf(session,
3387 " ... %llu,\n",
3388 entry->end.value);
3389 }
3390 }
3391 if (ret)
3392 goto end;
3393 }
3394 }
3395 ret = print_tabs(session, nesting);
3396 if (ret)
3397 goto end;
3398 ret = lttng_metadata_printf(session, "}");
3399 end:
3400 return ret;
3401 }
3402
3403 /*
3404 * Must be called with sessions_mutex held.
3405 */
3406 static
3407 int _lttng_enum_field_statedump(struct lttng_session *session,
3408 const struct lttng_kernel_event_field *field,
3409 size_t nesting)
3410 {
3411 int ret;
3412 const struct lttng_kernel_type_enum *enum_type;
3413
3414 enum_type = lttng_kernel_get_type_enum(field->type);
3415 WARN_ON_ONCE(!enum_type);
3416 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3417 if (ret)
3418 return ret;
3419 return lttng_field_name_statedump(session, field, nesting);
3420 }
3421
3422 static
3423 int _lttng_integer_field_statedump(struct lttng_session *session,
3424 const struct lttng_kernel_event_field *field,
3425 size_t nesting)
3426 {
3427 int ret;
3428
3429 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3430 lttng_kernel_string_encoding_none, nesting);
3431 if (ret)
3432 return ret;
3433 return lttng_field_name_statedump(session, field, nesting);
3434 }
3435
3436 static
3437 int _lttng_string_type_statedump(struct lttng_session *session,
3438 const struct lttng_kernel_type_string *type,
3439 size_t nesting)
3440 {
3441 int ret;
3442
3443 /* Default encoding is UTF8 */
3444 ret = print_tabs(session, nesting);
3445 if (ret)
3446 return ret;
3447 ret = lttng_metadata_printf(session,
3448 "string%s",
3449 type->encoding == lttng_kernel_string_encoding_ASCII ?
3450 " { encoding = ASCII; }" : "");
3451 return ret;
3452 }
3453
3454 static
3455 int _lttng_string_field_statedump(struct lttng_session *session,
3456 const struct lttng_kernel_event_field *field,
3457 size_t nesting)
3458 {
3459 const struct lttng_kernel_type_string *string_type;
3460 int ret;
3461
3462 string_type = lttng_kernel_get_type_string(field->type);
3463 WARN_ON_ONCE(!string_type);
3464 ret = _lttng_string_type_statedump(session, string_type, nesting);
3465 if (ret)
3466 return ret;
3467 return lttng_field_name_statedump(session, field, nesting);
3468 }
3469
3470 /*
3471 * Must be called with sessions_mutex held.
3472 */
3473 static
3474 int _lttng_type_statedump(struct lttng_session *session,
3475 const struct lttng_kernel_type_common *type,
3476 enum lttng_kernel_string_encoding parent_encoding,
3477 size_t nesting)
3478 {
3479 int ret = 0;
3480
3481 switch (type->type) {
3482 case lttng_kernel_type_integer:
3483 ret = _lttng_integer_type_statedump(session,
3484 lttng_kernel_get_type_integer(type),
3485 parent_encoding, nesting);
3486 break;
3487 case lttng_kernel_type_enum:
3488 ret = _lttng_enum_type_statedump(session,
3489 lttng_kernel_get_type_enum(type),
3490 nesting);
3491 break;
3492 case lttng_kernel_type_string:
3493 ret = _lttng_string_type_statedump(session,
3494 lttng_kernel_get_type_string(type),
3495 nesting);
3496 break;
3497 case lttng_kernel_type_struct:
3498 ret = _lttng_struct_type_statedump(session,
3499 lttng_kernel_get_type_struct(type),
3500 nesting);
3501 break;
3502 case lttng_kernel_type_variant:
3503 ret = _lttng_variant_type_statedump(session,
3504 lttng_kernel_get_type_variant(type),
3505 nesting, NULL);
3506 break;
3507
3508 /* Nested arrays and sequences are not supported yet. */
3509 case lttng_kernel_type_array:
3510 case lttng_kernel_type_sequence:
3511 default:
3512 WARN_ON_ONCE(1);
3513 return -EINVAL;
3514 }
3515 return ret;
3516 }
3517
3518 /*
3519 * Must be called with sessions_mutex held.
3520 */
3521 static
3522 int _lttng_field_statedump(struct lttng_session *session,
3523 const struct lttng_kernel_event_field *field,
3524 size_t nesting,
3525 const char **prev_field_name_p)
3526 {
3527 const char *prev_field_name = NULL;
3528 int ret = 0;
3529
3530 if (prev_field_name_p)
3531 prev_field_name = *prev_field_name_p;
3532 switch (field->type->type) {
3533 case lttng_kernel_type_integer:
3534 ret = _lttng_integer_field_statedump(session, field, nesting);
3535 break;
3536 case lttng_kernel_type_enum:
3537 ret = _lttng_enum_field_statedump(session, field, nesting);
3538 break;
3539 case lttng_kernel_type_string:
3540 ret = _lttng_string_field_statedump(session, field, nesting);
3541 break;
3542 case lttng_kernel_type_struct:
3543 ret = _lttng_struct_field_statedump(session, field, nesting);
3544 break;
3545 case lttng_kernel_type_array:
3546 ret = _lttng_array_field_statedump(session, field, nesting);
3547 break;
3548 case lttng_kernel_type_sequence:
3549 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3550 break;
3551 case lttng_kernel_type_variant:
3552 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3553 break;
3554
3555 default:
3556 WARN_ON_ONCE(1);
3557 return -EINVAL;
3558 }
3559 if (prev_field_name_p)
3560 *prev_field_name_p = field->name;
3561 return ret;
3562 }
3563
3564 static
3565 int _lttng_context_metadata_statedump(struct lttng_session *session,
3566 struct lttng_kernel_ctx *ctx)
3567 {
3568 const char *prev_field_name = NULL;
3569 int ret = 0;
3570 int i;
3571
3572 if (!ctx)
3573 return 0;
3574 for (i = 0; i < ctx->nr_fields; i++) {
3575 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3576
3577 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3578 if (ret)
3579 return ret;
3580 }
3581 return ret;
3582 }
3583
3584 static
3585 int _lttng_fields_metadata_statedump(struct lttng_session *session,
3586 struct lttng_kernel_event_recorder *event_recorder)
3587 {
3588 const char *prev_field_name = NULL;
3589 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3590 int ret = 0;
3591 int i;
3592
3593 for (i = 0; i < desc->nr_fields; i++) {
3594 const struct lttng_kernel_event_field *field = desc->fields[i];
3595
3596 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3597 if (ret)
3598 return ret;
3599 }
3600 return ret;
3601 }
3602
3603 /*
3604 * Must be called with sessions_mutex held.
3605 * The entire event metadata is printed as a single atomic metadata
3606 * transaction.
3607 */
3608 static
3609 int _lttng_event_metadata_statedump(struct lttng_session *session,
3610 struct lttng_channel *chan,
3611 struct lttng_kernel_event_recorder *event_recorder)
3612 {
3613 int ret = 0;
3614
3615 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3616 return 0;
3617 if (chan->channel_type == METADATA_CHANNEL)
3618 return 0;
3619
3620 lttng_metadata_begin(session);
3621
3622 ret = lttng_metadata_printf(session,
3623 "event {\n"
3624 " name = \"%s\";\n"
3625 " id = %u;\n"
3626 " stream_id = %u;\n",
3627 event_recorder->priv->parent.desc->event_name,
3628 event_recorder->priv->id,
3629 event_recorder->chan->id);
3630 if (ret)
3631 goto end;
3632
3633 ret = lttng_metadata_printf(session,
3634 " fields := struct {\n"
3635 );
3636 if (ret)
3637 goto end;
3638
3639 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3640 if (ret)
3641 goto end;
3642
3643 /*
3644 * LTTng space reservation can only reserve multiples of the
3645 * byte size.
3646 */
3647 ret = lttng_metadata_printf(session,
3648 " };\n"
3649 "};\n\n");
3650 if (ret)
3651 goto end;
3652
3653 event_recorder->priv->metadata_dumped = 1;
3654 end:
3655 lttng_metadata_end(session);
3656 return ret;
3657
3658 }
3659
3660 /*
3661 * Must be called with sessions_mutex held.
3662 * The entire channel metadata is printed as a single atomic metadata
3663 * transaction.
3664 */
3665 static
3666 int _lttng_channel_metadata_statedump(struct lttng_session *session,
3667 struct lttng_channel *chan)
3668 {
3669 int ret = 0;
3670
3671 if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3672 return 0;
3673
3674 if (chan->channel_type == METADATA_CHANNEL)
3675 return 0;
3676
3677 lttng_metadata_begin(session);
3678
3679 WARN_ON_ONCE(!chan->header_type);
3680 ret = lttng_metadata_printf(session,
3681 "stream {\n"
3682 " id = %u;\n"
3683 " event.header := %s;\n"
3684 " packet.context := struct packet_context;\n",
3685 chan->id,
3686 chan->header_type == 1 ? "struct event_header_compact" :
3687 "struct event_header_large");
3688 if (ret)
3689 goto end;
3690
3691 if (chan->ctx) {
3692 ret = lttng_metadata_printf(session,
3693 " event.context := struct {\n");
3694 if (ret)
3695 goto end;
3696 }
3697 ret = _lttng_context_metadata_statedump(session, chan->ctx);
3698 if (ret)
3699 goto end;
3700 if (chan->ctx) {
3701 ret = lttng_metadata_printf(session,
3702 " };\n");
3703 if (ret)
3704 goto end;
3705 }
3706
3707 ret = lttng_metadata_printf(session,
3708 "};\n\n");
3709
3710 chan->metadata_dumped = 1;
3711 end:
3712 lttng_metadata_end(session);
3713 return ret;
3714 }
3715
3716 /*
3717 * Must be called with sessions_mutex held.
3718 */
3719 static
3720 int _lttng_stream_packet_context_declare(struct lttng_session *session)
3721 {
3722 return lttng_metadata_printf(session,
3723 "struct packet_context {\n"
3724 " uint64_clock_monotonic_t timestamp_begin;\n"
3725 " uint64_clock_monotonic_t timestamp_end;\n"
3726 " uint64_t content_size;\n"
3727 " uint64_t packet_size;\n"
3728 " uint64_t packet_seq_num;\n"
3729 " unsigned long events_discarded;\n"
3730 " uint32_t cpu_id;\n"
3731 "};\n\n"
3732 );
3733 }
3734
3735 /*
3736 * Compact header:
3737 * id: range: 0 - 30.
3738 * id 31 is reserved to indicate an extended header.
3739 *
3740 * Large header:
3741 * id: range: 0 - 65534.
3742 * id 65535 is reserved to indicate an extended header.
3743 *
3744 * Must be called with sessions_mutex held.
3745 */
3746 static
3747 int _lttng_event_header_declare(struct lttng_session *session)
3748 {
3749 return lttng_metadata_printf(session,
3750 "struct event_header_compact {\n"
3751 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3752 " variant <id> {\n"
3753 " struct {\n"
3754 " uint27_clock_monotonic_t timestamp;\n"
3755 " } compact;\n"
3756 " struct {\n"
3757 " uint32_t id;\n"
3758 " uint64_clock_monotonic_t timestamp;\n"
3759 " } extended;\n"
3760 " } v;\n"
3761 "} align(%u);\n"
3762 "\n"
3763 "struct event_header_large {\n"
3764 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3765 " variant <id> {\n"
3766 " struct {\n"
3767 " uint32_clock_monotonic_t timestamp;\n"
3768 " } compact;\n"
3769 " struct {\n"
3770 " uint32_t id;\n"
3771 " uint64_clock_monotonic_t timestamp;\n"
3772 " } extended;\n"
3773 " } v;\n"
3774 "} align(%u);\n\n",
3775 lttng_alignof(uint32_t) * CHAR_BIT,
3776 lttng_alignof(uint16_t) * CHAR_BIT
3777 );
3778 }
3779
3780 /*
3781 * Approximation of NTP time of day to clock monotonic correlation,
3782 * taken at start of trace.
3783 * Yes, this is only an approximation. Yes, we can (and will) do better
3784 * in future versions.
3785 * This function may return a negative offset. It may happen if the
3786 * system sets the REALTIME clock to 0 after boot.
3787 *
3788 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3789 * y2038 compliant.
3790 */
3791 static
3792 int64_t measure_clock_offset(void)
3793 {
3794 uint64_t monotonic_avg, monotonic[2], realtime;
3795 uint64_t tcf = trace_clock_freq();
3796 int64_t offset;
3797 unsigned long flags;
3798 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3799 struct timespec64 rts = { 0, 0 };
3800 #else
3801 struct timespec rts = { 0, 0 };
3802 #endif
3803
3804 /* Disable interrupts to increase correlation precision. */
3805 local_irq_save(flags);
3806 monotonic[0] = trace_clock_read64();
3807 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3808 ktime_get_real_ts64(&rts);
3809 #else
3810 getnstimeofday(&rts);
3811 #endif
3812 monotonic[1] = trace_clock_read64();
3813 local_irq_restore(flags);
3814
3815 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3816 realtime = (uint64_t) rts.tv_sec * tcf;
3817 if (tcf == NSEC_PER_SEC) {
3818 realtime += rts.tv_nsec;
3819 } else {
3820 uint64_t n = rts.tv_nsec * tcf;
3821
3822 do_div(n, NSEC_PER_SEC);
3823 realtime += n;
3824 }
3825 offset = (int64_t) realtime - monotonic_avg;
3826 return offset;
3827 }
3828
3829 static
3830 int print_escaped_ctf_string(struct lttng_session *session, const char *string)
3831 {
3832 int ret = 0;
3833 size_t i;
3834 char cur;
3835
3836 i = 0;
3837 cur = string[i];
3838 while (cur != '\0') {
3839 switch (cur) {
3840 case '\n':
3841 ret = lttng_metadata_printf(session, "%s", "\\n");
3842 break;
3843 case '\\':
3844 case '"':
3845 ret = lttng_metadata_printf(session, "%c", '\\');
3846 if (ret)
3847 goto error;
3848 /* We still print the current char */
3849 /* Fallthrough */
3850 default:
3851 ret = lttng_metadata_printf(session, "%c", cur);
3852 break;
3853 }
3854
3855 if (ret)
3856 goto error;
3857
3858 cur = string[++i];
3859 }
3860 error:
3861 return ret;
3862 }
3863
3864 static
3865 int print_metadata_escaped_field(struct lttng_session *session, const char *field,
3866 const char *field_value)
3867 {
3868 int ret;
3869
3870 ret = lttng_metadata_printf(session, " %s = \"", field);
3871 if (ret)
3872 goto error;
3873
3874 ret = print_escaped_ctf_string(session, field_value);
3875 if (ret)
3876 goto error;
3877
3878 ret = lttng_metadata_printf(session, "\";\n");
3879
3880 error:
3881 return ret;
3882 }
3883
3884 /*
3885 * Output metadata into this session's metadata buffers.
3886 * Must be called with sessions_mutex held.
3887 */
3888 static
3889 int _lttng_session_metadata_statedump(struct lttng_session *session)
3890 {
3891 unsigned char *uuid_c = session->uuid.b;
3892 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3893 const char *product_uuid;
3894 struct lttng_channel *chan;
3895 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3896 int ret = 0;
3897
3898 if (!LTTNG_READ_ONCE(session->active))
3899 return 0;
3900
3901 lttng_metadata_begin(session);
3902
3903 if (session->metadata_dumped)
3904 goto skip_session;
3905
3906 snprintf(uuid_s, sizeof(uuid_s),
3907 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3908 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3909 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3910 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3911 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3912
3913 ret = lttng_metadata_printf(session,
3914 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3915 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3916 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3917 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3918 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3919 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3920 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3921 "\n"
3922 "trace {\n"
3923 " major = %u;\n"
3924 " minor = %u;\n"
3925 " uuid = \"%s\";\n"
3926 " byte_order = %s;\n"
3927 " packet.header := struct {\n"
3928 " uint32_t magic;\n"
3929 " uint8_t uuid[16];\n"
3930 " uint32_t stream_id;\n"
3931 " uint64_t stream_instance_id;\n"
3932 " };\n"
3933 "};\n\n",
3934 lttng_alignof(uint8_t) * CHAR_BIT,
3935 lttng_alignof(uint16_t) * CHAR_BIT,
3936 lttng_alignof(uint32_t) * CHAR_BIT,
3937 lttng_alignof(uint64_t) * CHAR_BIT,
3938 sizeof(unsigned long) * CHAR_BIT,
3939 lttng_alignof(unsigned long) * CHAR_BIT,
3940 CTF_SPEC_MAJOR,
3941 CTF_SPEC_MINOR,
3942 uuid_s,
3943 #if __BYTE_ORDER == __BIG_ENDIAN
3944 "be"
3945 #else
3946 "le"
3947 #endif
3948 );
3949 if (ret)
3950 goto end;
3951
3952 ret = lttng_metadata_printf(session,
3953 "env {\n"
3954 " hostname = \"%s\";\n"
3955 " domain = \"kernel\";\n"
3956 " sysname = \"%s\";\n"
3957 " kernel_release = \"%s\";\n"
3958 " kernel_version = \"%s\";\n"
3959 " tracer_name = \"lttng-modules\";\n"
3960 " tracer_major = %d;\n"
3961 " tracer_minor = %d;\n"
3962 " tracer_patchlevel = %d;\n"
3963 " trace_buffering_scheme = \"global\";\n",
3964 current->nsproxy->uts_ns->name.nodename,
3965 utsname()->sysname,
3966 utsname()->release,
3967 utsname()->version,
3968 LTTNG_MODULES_MAJOR_VERSION,
3969 LTTNG_MODULES_MINOR_VERSION,
3970 LTTNG_MODULES_PATCHLEVEL_VERSION
3971 );
3972 if (ret)
3973 goto end;
3974
3975 ret = print_metadata_escaped_field(session, "trace_name", session->name);
3976 if (ret)
3977 goto end;
3978 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3979 session->creation_time);
3980 if (ret)
3981 goto end;
3982
3983 /* Add the product UUID to the 'env' section */
3984 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3985 if (product_uuid) {
3986 ret = lttng_metadata_printf(session,
3987 " product_uuid = \"%s\";\n",
3988 product_uuid
3989 );
3990 if (ret)
3991 goto end;
3992 }
3993
3994 /* Close the 'env' section */
3995 ret = lttng_metadata_printf(session, "};\n\n");
3996 if (ret)
3997 goto end;
3998
3999 ret = lttng_metadata_printf(session,
4000 "clock {\n"
4001 " name = \"%s\";\n",
4002 trace_clock_name()
4003 );
4004 if (ret)
4005 goto end;
4006
4007 if (!trace_clock_uuid(clock_uuid_s)) {
4008 ret = lttng_metadata_printf(session,
4009 " uuid = \"%s\";\n",
4010 clock_uuid_s
4011 );
4012 if (ret)
4013 goto end;
4014 }
4015
4016 ret = lttng_metadata_printf(session,
4017 " description = \"%s\";\n"
4018 " freq = %llu; /* Frequency, in Hz */\n"
4019 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
4020 " offset = %lld;\n"
4021 "};\n\n",
4022 trace_clock_description(),
4023 (unsigned long long) trace_clock_freq(),
4024 (long long) measure_clock_offset()
4025 );
4026 if (ret)
4027 goto end;
4028
4029 ret = lttng_metadata_printf(session,
4030 "typealias integer {\n"
4031 " size = 27; align = 1; signed = false;\n"
4032 " map = clock.%s.value;\n"
4033 "} := uint27_clock_monotonic_t;\n"
4034 "\n"
4035 "typealias integer {\n"
4036 " size = 32; align = %u; signed = false;\n"
4037 " map = clock.%s.value;\n"
4038 "} := uint32_clock_monotonic_t;\n"
4039 "\n"
4040 "typealias integer {\n"
4041 " size = 64; align = %u; signed = false;\n"
4042 " map = clock.%s.value;\n"
4043 "} := uint64_clock_monotonic_t;\n\n",
4044 trace_clock_name(),
4045 lttng_alignof(uint32_t) * CHAR_BIT,
4046 trace_clock_name(),
4047 lttng_alignof(uint64_t) * CHAR_BIT,
4048 trace_clock_name()
4049 );
4050 if (ret)
4051 goto end;
4052
4053 ret = _lttng_stream_packet_context_declare(session);
4054 if (ret)
4055 goto end;
4056
4057 ret = _lttng_event_header_declare(session);
4058 if (ret)
4059 goto end;
4060
4061 skip_session:
4062 list_for_each_entry(chan, &session->chan, list) {
4063 ret = _lttng_channel_metadata_statedump(session, chan);
4064 if (ret)
4065 goto end;
4066 }
4067
4068 list_for_each_entry(event_recorder_priv, &session->events, node) {
4069 ret = _lttng_event_metadata_statedump(session, event_recorder_priv->pub->chan,
4070 event_recorder_priv->pub);
4071 if (ret)
4072 goto end;
4073 }
4074 session->metadata_dumped = 1;
4075 end:
4076 lttng_metadata_end(session);
4077 return ret;
4078 }
4079
4080 /**
4081 * lttng_transport_register - LTT transport registration
4082 * @transport: transport structure
4083 *
4084 * Registers a transport which can be used as output to extract the data out of
4085 * LTTng. The module calling this registration function must ensure that no
4086 * trap-inducing code will be executed by the transport functions. E.g.
4087 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
4088 * is made visible to the transport function. This registration acts as a
4089 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
4090 * after its registration must it synchronize the TLBs.
4091 */
4092 void lttng_transport_register(struct lttng_transport *transport)
4093 {
4094 /*
4095 * Make sure no page fault can be triggered by the module about to be
4096 * registered. We deal with this here so we don't have to call
4097 * vmalloc_sync_mappings() in each module's init.
4098 */
4099 wrapper_vmalloc_sync_mappings();
4100
4101 mutex_lock(&sessions_mutex);
4102 list_add_tail(&transport->node, &lttng_transport_list);
4103 mutex_unlock(&sessions_mutex);
4104 }
4105 EXPORT_SYMBOL_GPL(lttng_transport_register);
4106
4107 /**
4108 * lttng_transport_unregister - LTT transport unregistration
4109 * @transport: transport structure
4110 */
4111 void lttng_transport_unregister(struct lttng_transport *transport)
4112 {
4113 mutex_lock(&sessions_mutex);
4114 list_del(&transport->node);
4115 mutex_unlock(&sessions_mutex);
4116 }
4117 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4118
4119 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4120 {
4121 /*
4122 * Make sure no page fault can be triggered by the module about to be
4123 * registered. We deal with this here so we don't have to call
4124 * vmalloc_sync_mappings() in each module's init.
4125 */
4126 wrapper_vmalloc_sync_mappings();
4127
4128 mutex_lock(&sessions_mutex);
4129 list_add_tail(&transport->node, &lttng_counter_transport_list);
4130 mutex_unlock(&sessions_mutex);
4131 }
4132 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4133
4134 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4135 {
4136 mutex_lock(&sessions_mutex);
4137 list_del(&transport->node);
4138 mutex_unlock(&sessions_mutex);
4139 }
4140 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4141
4142 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4143
4144 enum cpuhp_state lttng_hp_prepare;
4145 enum cpuhp_state lttng_hp_online;
4146
4147 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4148 {
4149 struct lttng_cpuhp_node *lttng_node;
4150
4151 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4152 switch (lttng_node->component) {
4153 case LTTNG_RING_BUFFER_FRONTEND:
4154 return 0;
4155 case LTTNG_RING_BUFFER_BACKEND:
4156 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4157 case LTTNG_RING_BUFFER_ITER:
4158 return 0;
4159 case LTTNG_CONTEXT_PERF_COUNTERS:
4160 return 0;
4161 default:
4162 return -EINVAL;
4163 }
4164 }
4165
4166 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4167 {
4168 struct lttng_cpuhp_node *lttng_node;
4169
4170 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4171 switch (lttng_node->component) {
4172 case LTTNG_RING_BUFFER_FRONTEND:
4173 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4174 case LTTNG_RING_BUFFER_BACKEND:
4175 return 0;
4176 case LTTNG_RING_BUFFER_ITER:
4177 return 0;
4178 case LTTNG_CONTEXT_PERF_COUNTERS:
4179 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4180 default:
4181 return -EINVAL;
4182 }
4183 }
4184
4185 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4186 {
4187 struct lttng_cpuhp_node *lttng_node;
4188
4189 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4190 switch (lttng_node->component) {
4191 case LTTNG_RING_BUFFER_FRONTEND:
4192 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4193 case LTTNG_RING_BUFFER_BACKEND:
4194 return 0;
4195 case LTTNG_RING_BUFFER_ITER:
4196 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4197 case LTTNG_CONTEXT_PERF_COUNTERS:
4198 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4199 default:
4200 return -EINVAL;
4201 }
4202 }
4203
4204 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4205 {
4206 struct lttng_cpuhp_node *lttng_node;
4207
4208 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4209 switch (lttng_node->component) {
4210 case LTTNG_RING_BUFFER_FRONTEND:
4211 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4212 case LTTNG_RING_BUFFER_BACKEND:
4213 return 0;
4214 case LTTNG_RING_BUFFER_ITER:
4215 return 0;
4216 case LTTNG_CONTEXT_PERF_COUNTERS:
4217 return 0;
4218 default:
4219 return -EINVAL;
4220 }
4221 }
4222
4223 static int __init lttng_init_cpu_hotplug(void)
4224 {
4225 int ret;
4226
4227 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4228 lttng_hotplug_prepare,
4229 lttng_hotplug_dead);
4230 if (ret < 0) {
4231 return ret;
4232 }
4233 lttng_hp_prepare = ret;
4234 lttng_rb_set_hp_prepare(ret);
4235
4236 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4237 lttng_hotplug_online,
4238 lttng_hotplug_offline);
4239 if (ret < 0) {
4240 cpuhp_remove_multi_state(lttng_hp_prepare);
4241 lttng_hp_prepare = 0;
4242 return ret;
4243 }
4244 lttng_hp_online = ret;
4245 lttng_rb_set_hp_online(ret);
4246
4247 return 0;
4248 }
4249
4250 static void __exit lttng_exit_cpu_hotplug(void)
4251 {
4252 lttng_rb_set_hp_online(0);
4253 cpuhp_remove_multi_state(lttng_hp_online);
4254 lttng_rb_set_hp_prepare(0);
4255 cpuhp_remove_multi_state(lttng_hp_prepare);
4256 }
4257
4258 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4259 static int lttng_init_cpu_hotplug(void)
4260 {
4261 return 0;
4262 }
4263 static void lttng_exit_cpu_hotplug(void)
4264 {
4265 }
4266 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4267
4268
4269 static int __init lttng_events_init(void)
4270 {
4271 int ret;
4272
4273 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4274 if (ret)
4275 return ret;
4276 ret = wrapper_get_pfnblock_flags_mask_init();
4277 if (ret)
4278 return ret;
4279 ret = wrapper_get_pageblock_flags_mask_init();
4280 if (ret)
4281 return ret;
4282 ret = lttng_probes_init();
4283 if (ret)
4284 return ret;
4285 ret = lttng_context_init();
4286 if (ret)
4287 return ret;
4288 ret = lttng_tracepoint_init();
4289 if (ret)
4290 goto error_tp;
4291 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4292 if (!event_recorder_cache) {
4293 ret = -ENOMEM;
4294 goto error_kmem_event_recorder;
4295 }
4296 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4297 if (!event_recorder_private_cache) {
4298 ret = -ENOMEM;
4299 goto error_kmem_event_recorder_private;
4300 }
4301 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4302 if (!event_notifier_cache) {
4303 ret = -ENOMEM;
4304 goto error_kmem_event_notifier;
4305 }
4306 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4307 if (!event_notifier_private_cache) {
4308 ret = -ENOMEM;
4309 goto error_kmem_event_notifier_private;
4310 }
4311 ret = lttng_abi_init();
4312 if (ret)
4313 goto error_abi;
4314 ret = lttng_logger_init();
4315 if (ret)
4316 goto error_logger;
4317 ret = lttng_init_cpu_hotplug();
4318 if (ret)
4319 goto error_hotplug;
4320 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4321 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4322 __stringify(LTTNG_MODULES_MINOR_VERSION),
4323 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4324 LTTNG_MODULES_EXTRAVERSION,
4325 LTTNG_VERSION_NAME,
4326 #ifdef LTTNG_EXTRA_VERSION_GIT
4327 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4328 #else
4329 "",
4330 #endif
4331 #ifdef LTTNG_EXTRA_VERSION_NAME
4332 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4333 #else
4334 "");
4335 #endif
4336 return 0;
4337
4338 error_hotplug:
4339 lttng_logger_exit();
4340 error_logger:
4341 lttng_abi_exit();
4342 error_abi:
4343 kmem_cache_destroy(event_notifier_private_cache);
4344 error_kmem_event_notifier_private:
4345 kmem_cache_destroy(event_notifier_cache);
4346 error_kmem_event_notifier:
4347 kmem_cache_destroy(event_recorder_private_cache);
4348 error_kmem_event_recorder_private:
4349 kmem_cache_destroy(event_recorder_cache);
4350 error_kmem_event_recorder:
4351 lttng_tracepoint_exit();
4352 error_tp:
4353 lttng_context_exit();
4354 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4355 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4356 __stringify(LTTNG_MODULES_MINOR_VERSION),
4357 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4358 LTTNG_MODULES_EXTRAVERSION,
4359 LTTNG_VERSION_NAME,
4360 #ifdef LTTNG_EXTRA_VERSION_GIT
4361 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4362 #else
4363 "",
4364 #endif
4365 #ifdef LTTNG_EXTRA_VERSION_NAME
4366 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4367 #else
4368 "");
4369 #endif
4370 return ret;
4371 }
4372
4373 module_init(lttng_events_init);
4374
4375 static void __exit lttng_events_exit(void)
4376 {
4377 struct lttng_session *session, *tmpsession;
4378
4379 lttng_exit_cpu_hotplug();
4380 lttng_logger_exit();
4381 lttng_abi_exit();
4382 list_for_each_entry_safe(session, tmpsession, &sessions, list)
4383 lttng_session_destroy(session);
4384 kmem_cache_destroy(event_recorder_cache);
4385 kmem_cache_destroy(event_recorder_private_cache);
4386 kmem_cache_destroy(event_notifier_cache);
4387 kmem_cache_destroy(event_notifier_private_cache);
4388 lttng_tracepoint_exit();
4389 lttng_context_exit();
4390 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4391 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4392 __stringify(LTTNG_MODULES_MINOR_VERSION),
4393 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4394 LTTNG_MODULES_EXTRAVERSION,
4395 LTTNG_VERSION_NAME,
4396 #ifdef LTTNG_EXTRA_VERSION_GIT
4397 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4398 #else
4399 "",
4400 #endif
4401 #ifdef LTTNG_EXTRA_VERSION_NAME
4402 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4403 #else
4404 "");
4405 #endif
4406 }
4407
4408 module_exit(lttng_events_exit);
4409
4410 #include <generated/patches.h>
4411 #ifdef LTTNG_EXTRA_VERSION_GIT
4412 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4413 #endif
4414 #ifdef LTTNG_EXTRA_VERSION_NAME
4415 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4416 #endif
4417 MODULE_LICENSE("GPL and additional rights");
4418 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4419 MODULE_DESCRIPTION("LTTng tracer");
4420 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4421 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4422 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4423 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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