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Rename "tsc" to "timestamp"
[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/compiler_attributes.h>
32 #include <wrapper/uuid.h>
33 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
34 #include <wrapper/random.h>
35 #include <wrapper/tracepoint.h>
36 #include <wrapper/list.h>
37 #include <wrapper/types.h>
38 #include <lttng/kernel-version.h>
39 #include <lttng/events.h>
40 #include <lttng/events-internal.h>
41 #include <lttng/lttng-bytecode.h>
42 #include <lttng/tracer.h>
43 #include <lttng/event-notifier-notification.h>
44 #include <lttng/abi-old.h>
45 #include <lttng/endian.h>
46 #include <lttng/string-utils.h>
47 #include <lttng/utils.h>
48 #include <ringbuffer/backend.h>
49 #include <ringbuffer/frontend.h>
50 #include <wrapper/time.h>
51
52 #define METADATA_CACHE_DEFAULT_SIZE 4096
53
54 static LIST_HEAD(sessions);
55 static LIST_HEAD(event_notifier_groups);
56 static LIST_HEAD(lttng_transport_list);
57 static LIST_HEAD(lttng_counter_transport_list);
58 /*
59 * Protect the sessions and metadata caches.
60 */
61 static DEFINE_MUTEX(sessions_mutex);
62 static struct kmem_cache *event_recorder_cache;
63 static struct kmem_cache *event_recorder_private_cache;
64 static struct kmem_cache *event_notifier_cache;
65 static struct kmem_cache *event_notifier_private_cache;
66
67 static void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session);
68 static void lttng_session_sync_event_enablers(struct lttng_kernel_session *session);
69 static void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler);
70 static void lttng_event_notifier_enabler_destroy(struct lttng_event_notifier_enabler *event_notifier_enabler);
71 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
72
73 static void _lttng_event_destroy(struct lttng_kernel_event_common *event);
74 static void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan);
75 static int _lttng_event_unregister(struct lttng_kernel_event_recorder *event);
76 static int _lttng_event_notifier_unregister(struct lttng_kernel_event_notifier *event_notifier);
77 static
78 int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
79 struct lttng_kernel_channel_buffer *chan,
80 struct lttng_kernel_event_recorder *event);
81 static
82 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session);
83 static
84 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
85 static
86 int _lttng_type_statedump(struct lttng_kernel_session *session,
87 const struct lttng_kernel_type_common *type,
88 enum lttng_kernel_string_encoding parent_encoding,
89 size_t nesting);
90 static
91 int _lttng_field_statedump(struct lttng_kernel_session *session,
92 const struct lttng_kernel_event_field *field,
93 size_t nesting, const char **prev_field_name_p);
94
95 void synchronize_trace(void)
96 {
97 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0) || \
98 LTTNG_RHEL_KERNEL_RANGE(4,18,0,193,0,0, 4,19,0,0,0,0))
99 synchronize_rcu();
100 #else
101 synchronize_sched();
102 #endif
103
104 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
105 #ifdef CONFIG_PREEMPT_RT_FULL
106 synchronize_rcu();
107 #endif
108 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
109 #ifdef CONFIG_PREEMPT_RT
110 synchronize_rcu();
111 #endif
112 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
113 }
114
115 void lttng_lock_sessions(void)
116 {
117 mutex_lock(&sessions_mutex);
118 }
119
120 void lttng_unlock_sessions(void)
121 {
122 mutex_unlock(&sessions_mutex);
123 }
124
125 static struct lttng_transport *lttng_transport_find(const char *name)
126 {
127 struct lttng_transport *transport;
128
129 list_for_each_entry(transport, &lttng_transport_list, node) {
130 if (!strcmp(transport->name, name))
131 return transport;
132 }
133 return NULL;
134 }
135
136 /*
137 * Called with sessions lock held.
138 */
139 int lttng_session_active(void)
140 {
141 struct lttng_kernel_session_private *iter;
142
143 list_for_each_entry(iter, &sessions, list) {
144 if (iter->pub->active)
145 return 1;
146 }
147 return 0;
148 }
149
150 struct lttng_kernel_session *lttng_session_create(void)
151 {
152 struct lttng_kernel_session *session;
153 struct lttng_kernel_session_private *session_priv;
154 struct lttng_metadata_cache *metadata_cache;
155 int i;
156
157 mutex_lock(&sessions_mutex);
158 session = lttng_kvzalloc(sizeof(*session), GFP_KERNEL);
159 if (!session)
160 goto err;
161 session_priv = lttng_kvzalloc(sizeof(*session_priv), GFP_KERNEL);
162 if (!session_priv)
163 goto err_free_session;
164 session->priv = session_priv;
165 session_priv->pub = session;
166
167 INIT_LIST_HEAD(&session_priv->chan);
168 INIT_LIST_HEAD(&session_priv->events);
169 lttng_guid_gen(&session_priv->uuid);
170
171 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
172 GFP_KERNEL);
173 if (!metadata_cache)
174 goto err_free_session_private;
175 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
176 if (!metadata_cache->data)
177 goto err_free_cache;
178 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
179 kref_init(&metadata_cache->refcount);
180 mutex_init(&metadata_cache->lock);
181 session_priv->metadata_cache = metadata_cache;
182 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
183 memcpy(&metadata_cache->uuid, &session_priv->uuid,
184 sizeof(metadata_cache->uuid));
185 INIT_LIST_HEAD(&session_priv->enablers_head);
186 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
187 INIT_HLIST_HEAD(&session_priv->events_ht.table[i]);
188 list_add(&session_priv->list, &sessions);
189
190 if (lttng_id_tracker_init(&session->pid_tracker, session, TRACKER_PID))
191 goto tracker_alloc_error;
192 if (lttng_id_tracker_init(&session->vpid_tracker, session, TRACKER_VPID))
193 goto tracker_alloc_error;
194 if (lttng_id_tracker_init(&session->uid_tracker, session, TRACKER_UID))
195 goto tracker_alloc_error;
196 if (lttng_id_tracker_init(&session->vuid_tracker, session, TRACKER_VUID))
197 goto tracker_alloc_error;
198 if (lttng_id_tracker_init(&session->gid_tracker, session, TRACKER_GID))
199 goto tracker_alloc_error;
200 if (lttng_id_tracker_init(&session->vgid_tracker, session, TRACKER_VGID))
201 goto tracker_alloc_error;
202
203 mutex_unlock(&sessions_mutex);
204
205 return session;
206
207 tracker_alloc_error:
208 lttng_id_tracker_fini(&session->pid_tracker);
209 lttng_id_tracker_fini(&session->vpid_tracker);
210 lttng_id_tracker_fini(&session->uid_tracker);
211 lttng_id_tracker_fini(&session->vuid_tracker);
212 lttng_id_tracker_fini(&session->gid_tracker);
213 lttng_id_tracker_fini(&session->vgid_tracker);
214 err_free_cache:
215 kfree(metadata_cache);
216 err_free_session_private:
217 lttng_kvfree(session_priv);
218 err_free_session:
219 lttng_kvfree(session);
220 err:
221 mutex_unlock(&sessions_mutex);
222 return NULL;
223 }
224
225 static
226 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
227 {
228 struct lttng_counter_transport *transport;
229
230 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
231 if (!strcmp(transport->name, name))
232 return transport;
233 }
234 return NULL;
235 }
236
237 struct lttng_counter *lttng_kernel_counter_create(
238 const char *counter_transport_name,
239 size_t number_dimensions, const size_t *dimensions_sizes)
240 {
241 struct lttng_counter *counter = NULL;
242 struct lttng_counter_transport *counter_transport = NULL;
243
244 counter_transport = lttng_counter_transport_find(counter_transport_name);
245 if (!counter_transport) {
246 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
247 counter_transport_name);
248 goto notransport;
249 }
250 if (!try_module_get(counter_transport->owner)) {
251 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
252 goto notransport;
253 }
254
255 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
256 if (!counter)
257 goto nomem;
258
259 /* Create event notifier error counter. */
260 counter->ops = &counter_transport->ops;
261 counter->transport = counter_transport;
262
263 counter->counter = counter->ops->counter_create(
264 number_dimensions, dimensions_sizes, 0);
265 if (!counter->counter) {
266 goto create_error;
267 }
268
269 return counter;
270
271 create_error:
272 lttng_kvfree(counter);
273 nomem:
274 if (counter_transport)
275 module_put(counter_transport->owner);
276 notransport:
277 return NULL;
278 }
279
280 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
281 {
282 struct lttng_transport *transport = NULL;
283 struct lttng_event_notifier_group *event_notifier_group;
284 const char *transport_name = "relay-event-notifier";
285 size_t subbuf_size = 4096; //TODO
286 size_t num_subbuf = 16; //TODO
287 unsigned int switch_timer_interval = 0;
288 unsigned int read_timer_interval = 0;
289 int i;
290
291 mutex_lock(&sessions_mutex);
292
293 transport = lttng_transport_find(transport_name);
294 if (!transport) {
295 printk(KERN_WARNING "LTTng: transport %s not found\n",
296 transport_name);
297 goto notransport;
298 }
299 if (!try_module_get(transport->owner)) {
300 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
301 transport_name);
302 goto notransport;
303 }
304
305 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
306 GFP_KERNEL);
307 if (!event_notifier_group)
308 goto nomem;
309
310 /*
311 * Initialize the ring buffer used to store event notifier
312 * notifications.
313 */
314 event_notifier_group->ops = &transport->ops;
315 event_notifier_group->chan = transport->ops.priv->channel_create(
316 transport_name, event_notifier_group, NULL,
317 subbuf_size, num_subbuf, switch_timer_interval,
318 read_timer_interval);
319 if (!event_notifier_group->chan)
320 goto create_error;
321
322 event_notifier_group->transport = transport;
323
324 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
325 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
326 for (i = 0; i < LTTNG_EVENT_NOTIFIER_HT_SIZE; i++)
327 INIT_HLIST_HEAD(&event_notifier_group->event_notifiers_ht.table[i]);
328
329 list_add(&event_notifier_group->node, &event_notifier_groups);
330
331 mutex_unlock(&sessions_mutex);
332
333 return event_notifier_group;
334
335 create_error:
336 lttng_kvfree(event_notifier_group);
337 nomem:
338 if (transport)
339 module_put(transport->owner);
340 notransport:
341 mutex_unlock(&sessions_mutex);
342 return NULL;
343 }
344
345 void metadata_cache_destroy(struct kref *kref)
346 {
347 struct lttng_metadata_cache *cache =
348 container_of(kref, struct lttng_metadata_cache, refcount);
349 vfree(cache->data);
350 kfree(cache);
351 }
352
353 void lttng_session_destroy(struct lttng_kernel_session *session)
354 {
355 struct lttng_kernel_channel_buffer_private *chan_priv, *tmpchan_priv;
356 struct lttng_kernel_event_recorder_private *event_recorder_priv, *tmpevent_recorder_priv;
357 struct lttng_metadata_stream *metadata_stream;
358 struct lttng_event_enabler *event_enabler, *tmp_event_enabler;
359 int ret;
360
361 mutex_lock(&sessions_mutex);
362 WRITE_ONCE(session->active, 0);
363 list_for_each_entry(chan_priv, &session->priv->chan, node) {
364 ret = lttng_syscalls_unregister_channel(chan_priv->pub);
365 WARN_ON(ret);
366 }
367 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
368 ret = _lttng_event_unregister(event_recorder_priv->pub);
369 WARN_ON(ret);
370 }
371 synchronize_trace(); /* Wait for in-flight events to complete */
372 list_for_each_entry(chan_priv, &session->priv->chan, node) {
373 ret = lttng_syscalls_destroy_event(chan_priv->pub);
374 WARN_ON(ret);
375 }
376 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
377 &session->priv->enablers_head, node)
378 lttng_event_enabler_destroy(event_enabler);
379 list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv, &session->priv->events, node)
380 _lttng_event_destroy(&event_recorder_priv->pub->parent);
381 list_for_each_entry_safe(chan_priv, tmpchan_priv, &session->priv->chan, node) {
382 BUG_ON(chan_priv->channel_type == METADATA_CHANNEL);
383 _lttng_channel_destroy(chan_priv->pub);
384 }
385 mutex_lock(&session->priv->metadata_cache->lock);
386 list_for_each_entry(metadata_stream, &session->priv->metadata_cache->metadata_stream, list)
387 _lttng_metadata_channel_hangup(metadata_stream);
388 mutex_unlock(&session->priv->metadata_cache->lock);
389 lttng_id_tracker_fini(&session->pid_tracker);
390 lttng_id_tracker_fini(&session->vpid_tracker);
391 lttng_id_tracker_fini(&session->uid_tracker);
392 lttng_id_tracker_fini(&session->vuid_tracker);
393 lttng_id_tracker_fini(&session->gid_tracker);
394 lttng_id_tracker_fini(&session->vgid_tracker);
395 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
396 list_del(&session->priv->list);
397 mutex_unlock(&sessions_mutex);
398 lttng_kvfree(session->priv);
399 lttng_kvfree(session);
400 }
401
402 void lttng_event_notifier_group_destroy(
403 struct lttng_event_notifier_group *event_notifier_group)
404 {
405 struct lttng_event_notifier_enabler *event_notifier_enabler, *tmp_event_notifier_enabler;
406 struct lttng_kernel_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
407 int ret;
408
409 if (!event_notifier_group)
410 return;
411
412 mutex_lock(&sessions_mutex);
413
414 ret = lttng_syscalls_unregister_event_notifier_group(event_notifier_group);
415 WARN_ON(ret);
416
417 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
418 &event_notifier_group->event_notifiers_head, node) {
419 ret = _lttng_event_notifier_unregister(event_notifier_priv->pub);
420 WARN_ON(ret);
421 }
422
423 /* Wait for in-flight event notifier to complete */
424 synchronize_trace();
425
426 irq_work_sync(&event_notifier_group->wakeup_pending);
427
428 kfree(event_notifier_group->sc_filter);
429
430 list_for_each_entry_safe(event_notifier_enabler, tmp_event_notifier_enabler,
431 &event_notifier_group->enablers_head, node)
432 lttng_event_notifier_enabler_destroy(event_notifier_enabler);
433
434 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
435 &event_notifier_group->event_notifiers_head, node)
436 _lttng_event_destroy(&event_notifier_priv->pub->parent);
437
438 if (event_notifier_group->error_counter) {
439 struct lttng_counter *error_counter = event_notifier_group->error_counter;
440
441 error_counter->ops->counter_destroy(error_counter->counter);
442 module_put(error_counter->transport->owner);
443 lttng_kvfree(error_counter);
444 event_notifier_group->error_counter = NULL;
445 }
446
447 event_notifier_group->ops->priv->channel_destroy(event_notifier_group->chan);
448 module_put(event_notifier_group->transport->owner);
449 list_del(&event_notifier_group->node);
450
451 mutex_unlock(&sessions_mutex);
452 lttng_kvfree(event_notifier_group);
453 }
454
455 int lttng_session_statedump(struct lttng_kernel_session *session)
456 {
457 int ret;
458
459 mutex_lock(&sessions_mutex);
460 ret = lttng_statedump_start(session);
461 mutex_unlock(&sessions_mutex);
462 return ret;
463 }
464
465 int lttng_session_enable(struct lttng_kernel_session *session)
466 {
467 int ret = 0;
468 struct lttng_kernel_channel_buffer_private *chan_priv;
469
470 mutex_lock(&sessions_mutex);
471 if (session->active) {
472 ret = -EBUSY;
473 goto end;
474 }
475
476 /* Set transient enabler state to "enabled" */
477 session->priv->tstate = 1;
478
479 /* We need to sync enablers with session before activation. */
480 lttng_session_sync_event_enablers(session);
481
482 /*
483 * Snapshot the number of events per channel to know the type of header
484 * we need to use.
485 */
486 list_for_each_entry(chan_priv, &session->priv->chan, node) {
487 if (chan_priv->header_type)
488 continue; /* don't change it if session stop/restart */
489 if (chan_priv->free_event_id < 31)
490 chan_priv->header_type = 1; /* compact */
491 else
492 chan_priv->header_type = 2; /* large */
493 }
494
495 /* Clear each stream's quiescent state. */
496 list_for_each_entry(chan_priv, &session->priv->chan, node) {
497 if (chan_priv->channel_type != METADATA_CHANNEL)
498 lib_ring_buffer_clear_quiescent_channel(chan_priv->rb_chan);
499 }
500
501 WRITE_ONCE(session->active, 1);
502 WRITE_ONCE(session->priv->been_active, 1);
503 ret = _lttng_session_metadata_statedump(session);
504 if (ret) {
505 WRITE_ONCE(session->active, 0);
506 goto end;
507 }
508 ret = lttng_statedump_start(session);
509 if (ret)
510 WRITE_ONCE(session->active, 0);
511 end:
512 mutex_unlock(&sessions_mutex);
513 return ret;
514 }
515
516 int lttng_session_disable(struct lttng_kernel_session *session)
517 {
518 int ret = 0;
519 struct lttng_kernel_channel_buffer_private *chan_priv;
520
521 mutex_lock(&sessions_mutex);
522 if (!session->active) {
523 ret = -EBUSY;
524 goto end;
525 }
526 WRITE_ONCE(session->active, 0);
527
528 /* Set transient enabler state to "disabled" */
529 session->priv->tstate = 0;
530 lttng_session_sync_event_enablers(session);
531
532 /* Set each stream's quiescent state. */
533 list_for_each_entry(chan_priv, &session->priv->chan, node) {
534 if (chan_priv->channel_type != METADATA_CHANNEL)
535 lib_ring_buffer_set_quiescent_channel(chan_priv->rb_chan);
536 }
537 end:
538 mutex_unlock(&sessions_mutex);
539 return ret;
540 }
541
542 int lttng_session_metadata_regenerate(struct lttng_kernel_session *session)
543 {
544 int ret = 0;
545 struct lttng_kernel_channel_buffer_private *chan_priv;
546 struct lttng_kernel_event_recorder_private *event_recorder_priv;
547 struct lttng_metadata_cache *cache = session->priv->metadata_cache;
548 struct lttng_metadata_stream *stream;
549
550 mutex_lock(&sessions_mutex);
551 if (!session->active) {
552 ret = -EBUSY;
553 goto end;
554 }
555
556 mutex_lock(&cache->lock);
557 memset(cache->data, 0, cache->cache_alloc);
558 cache->metadata_written = 0;
559 cache->version++;
560 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list) {
561 stream->metadata_out = 0;
562 stream->metadata_in = 0;
563 }
564 mutex_unlock(&cache->lock);
565
566 session->priv->metadata_dumped = 0;
567 list_for_each_entry(chan_priv, &session->priv->chan, node) {
568 chan_priv->metadata_dumped = 0;
569 }
570
571 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
572 event_recorder_priv->metadata_dumped = 0;
573 }
574
575 ret = _lttng_session_metadata_statedump(session);
576
577 end:
578 mutex_unlock(&sessions_mutex);
579 return ret;
580 }
581
582 int lttng_channel_enable(struct lttng_kernel_channel_buffer *channel)
583 {
584 int ret = 0;
585
586 mutex_lock(&sessions_mutex);
587 if (channel->priv->channel_type == METADATA_CHANNEL) {
588 ret = -EPERM;
589 goto end;
590 }
591 if (channel->parent.enabled) {
592 ret = -EEXIST;
593 goto end;
594 }
595 /* Set transient enabler state to "enabled" */
596 channel->priv->parent.tstate = 1;
597 lttng_session_sync_event_enablers(channel->parent.session);
598 /* Set atomically the state to "enabled" */
599 WRITE_ONCE(channel->parent.enabled, 1);
600 end:
601 mutex_unlock(&sessions_mutex);
602 return ret;
603 }
604
605 int lttng_channel_disable(struct lttng_kernel_channel_buffer *channel)
606 {
607 int ret = 0;
608
609 mutex_lock(&sessions_mutex);
610 if (channel->priv->channel_type == METADATA_CHANNEL) {
611 ret = -EPERM;
612 goto end;
613 }
614 if (!channel->parent.enabled) {
615 ret = -EEXIST;
616 goto end;
617 }
618 /* Set atomically the state to "disabled" */
619 WRITE_ONCE(channel->parent.enabled, 0);
620 /* Set transient enabler state to "enabled" */
621 channel->priv->parent.tstate = 0;
622 lttng_session_sync_event_enablers(channel->parent.session);
623 end:
624 mutex_unlock(&sessions_mutex);
625 return ret;
626 }
627
628 int lttng_event_enable(struct lttng_kernel_event_common *event)
629 {
630 int ret = 0;
631
632 mutex_lock(&sessions_mutex);
633 switch (event->type) {
634 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
635 {
636 struct lttng_kernel_event_recorder *event_recorder =
637 container_of(event, struct lttng_kernel_event_recorder, parent);
638
639 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
640 ret = -EPERM;
641 goto end;
642 }
643 break;
644 }
645 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
646 switch (event->priv->instrumentation) {
647 case LTTNG_KERNEL_ABI_KRETPROBE:
648 ret = -EINVAL;
649 goto end;
650 default:
651 break;
652 }
653 break;
654 default:
655 break;
656 }
657
658 if (event->enabled) {
659 ret = -EEXIST;
660 goto end;
661 }
662 switch (event->priv->instrumentation) {
663 case LTTNG_KERNEL_ABI_TRACEPOINT:
664 lttng_fallthrough;
665 case LTTNG_KERNEL_ABI_SYSCALL:
666 ret = -EINVAL;
667 break;
668
669 case LTTNG_KERNEL_ABI_KPROBE:
670 lttng_fallthrough;
671 case LTTNG_KERNEL_ABI_UPROBE:
672 WRITE_ONCE(event->enabled, 1);
673 break;
674
675 case LTTNG_KERNEL_ABI_KRETPROBE:
676 ret = lttng_kretprobes_event_enable_state(event, 1);
677 break;
678
679 case LTTNG_KERNEL_ABI_FUNCTION:
680 lttng_fallthrough;
681 case LTTNG_KERNEL_ABI_NOOP:
682 lttng_fallthrough;
683 default:
684 WARN_ON_ONCE(1);
685 ret = -EINVAL;
686 }
687 end:
688 mutex_unlock(&sessions_mutex);
689 return ret;
690 }
691
692 int lttng_event_disable(struct lttng_kernel_event_common *event)
693 {
694 int ret = 0;
695
696 mutex_lock(&sessions_mutex);
697 switch (event->type) {
698 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
699 {
700 struct lttng_kernel_event_recorder *event_recorder =
701 container_of(event, struct lttng_kernel_event_recorder, parent);
702
703 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
704 ret = -EPERM;
705 goto end;
706 }
707 break;
708 }
709 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
710 switch (event->priv->instrumentation) {
711 case LTTNG_KERNEL_ABI_KRETPROBE:
712 ret = -EINVAL;
713 goto end;
714 default:
715 break;
716 }
717 break;
718 default:
719 break;
720 }
721
722 if (!event->enabled) {
723 ret = -EEXIST;
724 goto end;
725 }
726 switch (event->priv->instrumentation) {
727 case LTTNG_KERNEL_ABI_TRACEPOINT:
728 lttng_fallthrough;
729 case LTTNG_KERNEL_ABI_SYSCALL:
730 ret = -EINVAL;
731 break;
732
733 case LTTNG_KERNEL_ABI_KPROBE:
734 lttng_fallthrough;
735 case LTTNG_KERNEL_ABI_UPROBE:
736 WRITE_ONCE(event->enabled, 0);
737 break;
738
739 case LTTNG_KERNEL_ABI_KRETPROBE:
740 ret = lttng_kretprobes_event_enable_state(event, 0);
741 break;
742
743 case LTTNG_KERNEL_ABI_FUNCTION:
744 lttng_fallthrough;
745 case LTTNG_KERNEL_ABI_NOOP:
746 lttng_fallthrough;
747 default:
748 WARN_ON_ONCE(1);
749 ret = -EINVAL;
750 }
751 end:
752 mutex_unlock(&sessions_mutex);
753 return ret;
754 }
755
756 struct lttng_kernel_channel_buffer *lttng_channel_create(struct lttng_kernel_session *session,
757 const char *transport_name,
758 void *buf_addr,
759 size_t subbuf_size, size_t num_subbuf,
760 unsigned int switch_timer_interval,
761 unsigned int read_timer_interval,
762 enum channel_type channel_type)
763 {
764 struct lttng_kernel_channel_buffer *chan;
765 struct lttng_kernel_channel_buffer_private *chan_priv;
766 struct lttng_transport *transport = NULL;
767
768 mutex_lock(&sessions_mutex);
769 if (session->priv->been_active && channel_type != METADATA_CHANNEL)
770 goto active; /* Refuse to add channel to active session */
771 transport = lttng_transport_find(transport_name);
772 if (!transport) {
773 printk(KERN_WARNING "LTTng: transport %s not found\n",
774 transport_name);
775 goto notransport;
776 }
777 if (!try_module_get(transport->owner)) {
778 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
779 goto notransport;
780 }
781 chan = kzalloc(sizeof(struct lttng_kernel_channel_buffer), GFP_KERNEL);
782 if (!chan)
783 goto nomem;
784 chan_priv = kzalloc(sizeof(struct lttng_kernel_channel_buffer_private), GFP_KERNEL);
785 if (!chan_priv)
786 goto nomem_priv;
787 chan->priv = chan_priv;
788 chan_priv->pub = chan;
789 chan->parent.type = LTTNG_KERNEL_CHANNEL_TYPE_BUFFER;
790 chan->parent.session = session;
791 chan->priv->id = session->priv->free_chan_id++;
792 chan->ops = &transport->ops;
793 /*
794 * Note: the channel creation op already writes into the packet
795 * headers. Therefore the "chan" information used as input
796 * should be already accessible.
797 */
798 chan->priv->rb_chan = transport->ops.priv->channel_create(transport_name,
799 chan, buf_addr, subbuf_size, num_subbuf,
800 switch_timer_interval, read_timer_interval);
801 if (!chan->priv->rb_chan)
802 goto create_error;
803 chan->priv->parent.tstate = 1;
804 chan->parent.enabled = 1;
805 chan->priv->transport = transport;
806 chan->priv->channel_type = channel_type;
807 list_add(&chan->priv->node, &session->priv->chan);
808 mutex_unlock(&sessions_mutex);
809 return chan;
810
811 create_error:
812 kfree(chan_priv);
813 nomem_priv:
814 kfree(chan);
815 nomem:
816 if (transport)
817 module_put(transport->owner);
818 notransport:
819 active:
820 mutex_unlock(&sessions_mutex);
821 return NULL;
822 }
823
824 /*
825 * Only used internally at session destruction for per-cpu channels, and
826 * when metadata channel is released.
827 * Needs to be called with sessions mutex held.
828 */
829 static
830 void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan)
831 {
832 chan->ops->priv->channel_destroy(chan->priv->rb_chan);
833 module_put(chan->priv->transport->owner);
834 list_del(&chan->priv->node);
835 lttng_kernel_destroy_context(chan->priv->ctx);
836 kfree(chan->priv);
837 kfree(chan);
838 }
839
840 void lttng_metadata_channel_destroy(struct lttng_kernel_channel_buffer *chan)
841 {
842 BUG_ON(chan->priv->channel_type != METADATA_CHANNEL);
843
844 /* Protect the metadata cache with the sessions_mutex. */
845 mutex_lock(&sessions_mutex);
846 _lttng_channel_destroy(chan);
847 mutex_unlock(&sessions_mutex);
848 }
849 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
850
851 static
852 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
853 {
854 stream->finalized = 1;
855 wake_up_interruptible(&stream->read_wait);
856 }
857
858
859 /*
860 * Supports event creation while tracing session is active.
861 * Needs to be called with sessions mutex held.
862 */
863 struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
864 struct lttng_kernel_abi_event *event_param,
865 const struct lttng_kernel_event_desc *event_desc,
866 enum lttng_kernel_abi_instrumentation itype)
867 {
868 struct lttng_kernel_session *session = chan->parent.session;
869 struct lttng_kernel_event_recorder *event_recorder;
870 struct lttng_kernel_event_recorder_private *event_recorder_priv;
871 const char *event_name;
872 struct hlist_head *head;
873 int ret;
874
875 if (chan->priv->free_event_id == -1U) {
876 ret = -EMFILE;
877 goto full;
878 }
879
880 switch (itype) {
881 case LTTNG_KERNEL_ABI_TRACEPOINT:
882 event_name = event_desc->event_name;
883 break;
884
885 case LTTNG_KERNEL_ABI_KPROBE:
886 lttng_fallthrough;
887 case LTTNG_KERNEL_ABI_UPROBE:
888 lttng_fallthrough;
889 case LTTNG_KERNEL_ABI_KRETPROBE:
890 lttng_fallthrough;
891 case LTTNG_KERNEL_ABI_SYSCALL:
892 event_name = event_param->name;
893 break;
894
895 case LTTNG_KERNEL_ABI_FUNCTION:
896 lttng_fallthrough;
897 case LTTNG_KERNEL_ABI_NOOP:
898 lttng_fallthrough;
899 default:
900 WARN_ON_ONCE(1);
901 ret = -EINVAL;
902 goto type_error;
903 }
904
905 head = utils_borrow_hash_table_bucket(session->priv->events_ht.table,
906 LTTNG_EVENT_HT_SIZE, event_name);
907 lttng_hlist_for_each_entry(event_recorder_priv, head, hlist) {
908 WARN_ON_ONCE(!event_recorder_priv->parent.desc);
909 if (!strncmp(event_recorder_priv->parent.desc->event_name, event_name,
910 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
911 && chan == event_recorder_priv->pub->chan) {
912 ret = -EEXIST;
913 goto exist;
914 }
915 }
916
917 event_recorder = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
918 if (!event_recorder) {
919 ret = -ENOMEM;
920 goto cache_error;
921 }
922 event_recorder_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
923 if (!event_recorder_priv) {
924 ret = -ENOMEM;
925 goto cache_private_error;
926 }
927 event_recorder_priv->pub = event_recorder;
928 event_recorder_priv->parent.pub = &event_recorder->parent;
929 event_recorder->priv = event_recorder_priv;
930 event_recorder->parent.priv = &event_recorder_priv->parent;
931 event_recorder->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
932
933 event_recorder->parent.run_filter = lttng_kernel_interpret_event_filter;
934 event_recorder->chan = chan;
935 event_recorder->priv->id = chan->priv->free_event_id++;
936 event_recorder->priv->parent.instrumentation = itype;
937 INIT_LIST_HEAD(&event_recorder->priv->parent.filter_bytecode_runtime_head);
938 INIT_LIST_HEAD(&event_recorder->priv->parent.enablers_ref_head);
939
940 switch (itype) {
941 case LTTNG_KERNEL_ABI_TRACEPOINT:
942 /* Event will be enabled by enabler sync. */
943 event_recorder->parent.enabled = 0;
944 event_recorder->priv->parent.registered = 0;
945 event_recorder->priv->parent.desc = lttng_event_desc_get(event_name);
946 if (!event_recorder->priv->parent.desc) {
947 ret = -ENOENT;
948 goto register_error;
949 }
950 /* Populate lttng_event structure before event registration. */
951 smp_wmb();
952 break;
953
954 case LTTNG_KERNEL_ABI_KPROBE:
955 /*
956 * Needs to be explicitly enabled after creation, since
957 * we may want to apply filters.
958 */
959 event_recorder->parent.enabled = 0;
960 event_recorder->priv->parent.registered = 1;
961 /*
962 * Populate lttng_event structure before event
963 * registration.
964 */
965 smp_wmb();
966 ret = lttng_kprobes_register_event(event_name,
967 event_param->u.kprobe.symbol_name,
968 event_param->u.kprobe.offset,
969 event_param->u.kprobe.addr,
970 event_recorder);
971 if (ret) {
972 ret = -EINVAL;
973 goto register_error;
974 }
975 ret = try_module_get(event_recorder->priv->parent.desc->owner);
976 WARN_ON_ONCE(!ret);
977 break;
978
979 case LTTNG_KERNEL_ABI_KRETPROBE:
980 {
981 struct lttng_kernel_event_recorder *event_recorder_return;
982 struct lttng_kernel_event_recorder_private *event_recorder_return_priv;
983
984 /* kretprobe defines 2 events */
985 /*
986 * Needs to be explicitly enabled after creation, since
987 * we may want to apply filters.
988 */
989 event_recorder->parent.enabled = 0;
990 event_recorder->priv->parent.registered = 1;
991
992 event_recorder_return = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
993 if (!event_recorder_return) {
994 ret = -ENOMEM;
995 goto register_error;
996 }
997 event_recorder_return_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
998 if (!event_recorder_return_priv) {
999 kmem_cache_free(event_recorder_cache, event_recorder_return);
1000 ret = -ENOMEM;
1001 goto register_error;
1002 }
1003 event_recorder_return_priv->pub = event_recorder_return;
1004 event_recorder_return_priv->parent.pub = &event_recorder_return->parent;
1005 event_recorder_return->priv = event_recorder_return_priv;
1006 event_recorder_return->parent.priv = &event_recorder_return_priv->parent;
1007 event_recorder_return->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
1008
1009 event_recorder_return->parent.run_filter = lttng_kernel_interpret_event_filter;
1010 event_recorder_return->chan = chan;
1011 event_recorder_return->priv->id = chan->priv->free_event_id++;
1012 event_recorder_return->priv->parent.instrumentation = itype;
1013 event_recorder_return->parent.enabled = 0;
1014 event_recorder_return->priv->parent.registered = 1;
1015 INIT_LIST_HEAD(&event_recorder_return->priv->parent.filter_bytecode_runtime_head);
1016 INIT_LIST_HEAD(&event_recorder_return->priv->parent.enablers_ref_head);
1017 /*
1018 * Populate lttng_event structure before kretprobe registration.
1019 */
1020 smp_wmb();
1021 ret = lttng_kretprobes_register(event_name,
1022 event_param->u.kretprobe.symbol_name,
1023 event_param->u.kretprobe.offset,
1024 event_param->u.kretprobe.addr,
1025 event_recorder, event_recorder_return);
1026 if (ret) {
1027 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
1028 kmem_cache_free(event_recorder_cache, event_recorder_return);
1029 ret = -EINVAL;
1030 goto register_error;
1031 }
1032 /* Take 2 refs on the module: one per event. */
1033 ret = try_module_get(event_recorder->priv->parent.desc->owner);
1034 WARN_ON_ONCE(!ret);
1035 ret = try_module_get(event_recorder_return->priv->parent.desc->owner);
1036 WARN_ON_ONCE(!ret);
1037 ret = _lttng_event_metadata_statedump(chan->parent.session, chan,
1038 event_recorder_return);
1039 WARN_ON_ONCE(ret > 0);
1040 if (ret) {
1041 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
1042 kmem_cache_free(event_recorder_cache, event_recorder_return);
1043 module_put(event_recorder_return->priv->parent.desc->owner);
1044 module_put(event_recorder->priv->parent.desc->owner);
1045 goto statedump_error;
1046 }
1047 list_add(&event_recorder_return->priv->node, &chan->parent.session->priv->events);
1048 break;
1049 }
1050
1051 case LTTNG_KERNEL_ABI_SYSCALL:
1052 /*
1053 * Needs to be explicitly enabled after creation, since
1054 * we may want to apply filters.
1055 */
1056 event_recorder->parent.enabled = 0;
1057 event_recorder->priv->parent.registered = 0;
1058 event_recorder->priv->parent.desc = event_desc;
1059 switch (event_param->u.syscall.entryexit) {
1060 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1061 ret = -EINVAL;
1062 goto register_error;
1063 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1064 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1065 break;
1066 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1067 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1068 break;
1069 }
1070 switch (event_param->u.syscall.abi) {
1071 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1072 ret = -EINVAL;
1073 goto register_error;
1074 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1075 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1076 break;
1077 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1078 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1079 break;
1080 }
1081 if (!event_recorder->priv->parent.desc) {
1082 ret = -EINVAL;
1083 goto register_error;
1084 }
1085 break;
1086
1087 case LTTNG_KERNEL_ABI_UPROBE:
1088 /*
1089 * Needs to be explicitly enabled after creation, since
1090 * we may want to apply filters.
1091 */
1092 event_recorder->parent.enabled = 0;
1093 event_recorder->priv->parent.registered = 1;
1094
1095 /*
1096 * Populate lttng_event structure before event
1097 * registration.
1098 */
1099 smp_wmb();
1100
1101 ret = lttng_uprobes_register_event(event_param->name,
1102 event_param->u.uprobe.fd,
1103 event_recorder);
1104 if (ret)
1105 goto register_error;
1106 ret = try_module_get(event_recorder->priv->parent.desc->owner);
1107 WARN_ON_ONCE(!ret);
1108 break;
1109
1110 case LTTNG_KERNEL_ABI_FUNCTION:
1111 lttng_fallthrough;
1112 case LTTNG_KERNEL_ABI_NOOP:
1113 lttng_fallthrough;
1114 default:
1115 WARN_ON_ONCE(1);
1116 ret = -EINVAL;
1117 goto register_error;
1118 }
1119 ret = _lttng_event_metadata_statedump(chan->parent.session, chan, event_recorder);
1120 WARN_ON_ONCE(ret > 0);
1121 if (ret) {
1122 goto statedump_error;
1123 }
1124 hlist_add_head(&event_recorder->priv->hlist, head);
1125 list_add(&event_recorder->priv->node, &chan->parent.session->priv->events);
1126 return event_recorder;
1127
1128 statedump_error:
1129 /* If a statedump error occurs, events will not be readable. */
1130 register_error:
1131 kmem_cache_free(event_recorder_private_cache, event_recorder_priv);
1132 cache_private_error:
1133 kmem_cache_free(event_recorder_cache, event_recorder);
1134 cache_error:
1135 exist:
1136 type_error:
1137 full:
1138 return ERR_PTR(ret);
1139 }
1140
1141 struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
1142 const struct lttng_kernel_event_desc *event_desc,
1143 uint64_t token, uint64_t error_counter_index,
1144 struct lttng_event_notifier_group *event_notifier_group,
1145 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1146 enum lttng_kernel_abi_instrumentation itype)
1147 {
1148 struct lttng_kernel_event_notifier *event_notifier;
1149 struct lttng_kernel_event_notifier_private *event_notifier_priv;
1150 struct lttng_counter *error_counter;
1151 const char *event_name;
1152 struct hlist_head *head;
1153 int ret;
1154
1155 switch (itype) {
1156 case LTTNG_KERNEL_ABI_TRACEPOINT:
1157 event_name = event_desc->event_name;
1158 break;
1159
1160 case LTTNG_KERNEL_ABI_KPROBE:
1161 lttng_fallthrough;
1162 case LTTNG_KERNEL_ABI_UPROBE:
1163 lttng_fallthrough;
1164 case LTTNG_KERNEL_ABI_SYSCALL:
1165 event_name = event_notifier_param->event.name;
1166 break;
1167
1168 case LTTNG_KERNEL_ABI_KRETPROBE:
1169 lttng_fallthrough;
1170 case LTTNG_KERNEL_ABI_FUNCTION:
1171 lttng_fallthrough;
1172 case LTTNG_KERNEL_ABI_NOOP:
1173 lttng_fallthrough;
1174 default:
1175 WARN_ON_ONCE(1);
1176 ret = -EINVAL;
1177 goto type_error;
1178 }
1179
1180 head = utils_borrow_hash_table_bucket(event_notifier_group->event_notifiers_ht.table,
1181 LTTNG_EVENT_NOTIFIER_HT_SIZE, event_name);
1182 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
1183 WARN_ON_ONCE(!event_notifier_priv->parent.desc);
1184 if (!strncmp(event_notifier_priv->parent.desc->event_name, event_name,
1185 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
1186 && event_notifier_group == event_notifier_priv->group
1187 && token == event_notifier_priv->parent.user_token) {
1188 ret = -EEXIST;
1189 goto exist;
1190 }
1191 }
1192
1193 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
1194 if (!event_notifier) {
1195 ret = -ENOMEM;
1196 goto cache_error;
1197 }
1198 event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
1199 if (!event_notifier_priv) {
1200 ret = -ENOMEM;
1201 goto cache_private_error;
1202 }
1203 event_notifier_priv->pub = event_notifier;
1204 event_notifier_priv->parent.pub = &event_notifier->parent;
1205 event_notifier->priv = event_notifier_priv;
1206 event_notifier->parent.priv = &event_notifier_priv->parent;
1207 event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
1208
1209 event_notifier->priv->group = event_notifier_group;
1210 event_notifier->priv->parent.user_token = token;
1211 event_notifier->priv->error_counter_index = error_counter_index;
1212 event_notifier->priv->num_captures = 0;
1213 event_notifier->priv->parent.instrumentation = itype;
1214 event_notifier->notification_send = lttng_event_notifier_notification_send;
1215 INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
1216 INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
1217 INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
1218 event_notifier->parent.run_filter = lttng_kernel_interpret_event_filter;
1219
1220 switch (itype) {
1221 case LTTNG_KERNEL_ABI_TRACEPOINT:
1222 /* Event will be enabled by enabler sync. */
1223 event_notifier->parent.enabled = 0;
1224 event_notifier->priv->parent.registered = 0;
1225 event_notifier->priv->parent.desc = lttng_event_desc_get(event_name);
1226 if (!event_notifier->priv->parent.desc) {
1227 ret = -ENOENT;
1228 goto register_error;
1229 }
1230 /* Populate lttng_event_notifier structure before event registration. */
1231 smp_wmb();
1232 break;
1233
1234 case LTTNG_KERNEL_ABI_KPROBE:
1235 /*
1236 * Needs to be explicitly enabled after creation, since
1237 * we may want to apply filters.
1238 */
1239 event_notifier->parent.enabled = 0;
1240 event_notifier->priv->parent.registered = 1;
1241 /*
1242 * Populate lttng_event_notifier structure before event
1243 * registration.
1244 */
1245 smp_wmb();
1246 ret = lttng_kprobes_register_event_notifier(
1247 event_notifier_param->event.u.kprobe.symbol_name,
1248 event_notifier_param->event.u.kprobe.offset,
1249 event_notifier_param->event.u.kprobe.addr,
1250 event_notifier);
1251 if (ret) {
1252 ret = -EINVAL;
1253 goto register_error;
1254 }
1255 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1256 WARN_ON_ONCE(!ret);
1257 break;
1258
1259 case LTTNG_KERNEL_ABI_SYSCALL:
1260 /*
1261 * Needs to be explicitly enabled after creation, since
1262 * we may want to apply filters.
1263 */
1264 event_notifier->parent.enabled = 0;
1265 event_notifier->priv->parent.registered = 0;
1266 event_notifier->priv->parent.desc = event_desc;
1267 switch (event_notifier_param->event.u.syscall.entryexit) {
1268 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1269 ret = -EINVAL;
1270 goto register_error;
1271 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1272 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1273 break;
1274 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1275 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1276 break;
1277 }
1278 switch (event_notifier_param->event.u.syscall.abi) {
1279 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1280 ret = -EINVAL;
1281 goto register_error;
1282 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1283 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1284 break;
1285 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1286 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1287 break;
1288 }
1289
1290 if (!event_notifier->priv->parent.desc) {
1291 ret = -EINVAL;
1292 goto register_error;
1293 }
1294 break;
1295
1296 case LTTNG_KERNEL_ABI_UPROBE:
1297 /*
1298 * Needs to be explicitly enabled after creation, since
1299 * we may want to apply filters.
1300 */
1301 event_notifier->parent.enabled = 0;
1302 event_notifier->priv->parent.registered = 1;
1303
1304 /*
1305 * Populate lttng_event_notifier structure before
1306 * event_notifier registration.
1307 */
1308 smp_wmb();
1309
1310 ret = lttng_uprobes_register_event_notifier(
1311 event_notifier_param->event.name,
1312 event_notifier_param->event.u.uprobe.fd,
1313 event_notifier);
1314 if (ret)
1315 goto register_error;
1316 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1317 WARN_ON_ONCE(!ret);
1318 break;
1319
1320 case LTTNG_KERNEL_ABI_KRETPROBE:
1321 lttng_fallthrough;
1322 case LTTNG_KERNEL_ABI_FUNCTION:
1323 lttng_fallthrough;
1324 case LTTNG_KERNEL_ABI_NOOP:
1325 lttng_fallthrough;
1326 default:
1327 WARN_ON_ONCE(1);
1328 ret = -EINVAL;
1329 goto register_error;
1330 }
1331
1332 list_add(&event_notifier->priv->node, &event_notifier_group->event_notifiers_head);
1333 hlist_add_head(&event_notifier->priv->hlist, head);
1334
1335 /*
1336 * Clear the error counter bucket. The sessiond keeps track of which
1337 * bucket is currently in use. We trust it. The session lock
1338 * synchronizes against concurrent creation of the error
1339 * counter.
1340 */
1341 error_counter = event_notifier_group->error_counter;
1342 if (error_counter) {
1343 size_t dimension_index[1];
1344
1345 /*
1346 * Check that the index is within the boundary of the counter.
1347 */
1348 if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
1349 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1350 event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
1351 ret = -EINVAL;
1352 goto register_error;
1353 }
1354
1355 dimension_index[0] = event_notifier->priv->error_counter_index;
1356 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1357 if (ret) {
1358 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1359 event_notifier->priv->error_counter_index);
1360 goto register_error;
1361 }
1362 }
1363
1364 return event_notifier;
1365
1366 register_error:
1367 kmem_cache_free(event_notifier_private_cache, event_notifier_priv);
1368 cache_private_error:
1369 kmem_cache_free(event_notifier_cache, event_notifier);
1370 cache_error:
1371 exist:
1372 type_error:
1373 return ERR_PTR(ret);
1374 }
1375
1376 int lttng_kernel_counter_read(struct lttng_counter *counter,
1377 const size_t *dim_indexes, int32_t cpu,
1378 int64_t *val, bool *overflow, bool *underflow)
1379 {
1380 return counter->ops->counter_read(counter->counter, dim_indexes,
1381 cpu, val, overflow, underflow);
1382 }
1383
1384 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1385 const size_t *dim_indexes, int64_t *val,
1386 bool *overflow, bool *underflow)
1387 {
1388 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1389 val, overflow, underflow);
1390 }
1391
1392 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1393 const size_t *dim_indexes)
1394 {
1395 return counter->ops->counter_clear(counter->counter, dim_indexes);
1396 }
1397
1398 struct lttng_kernel_event_recorder *lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
1399 struct lttng_kernel_abi_event *event_param,
1400 const struct lttng_kernel_event_desc *event_desc,
1401 enum lttng_kernel_abi_instrumentation itype)
1402 {
1403 struct lttng_kernel_event_recorder *event;
1404
1405 mutex_lock(&sessions_mutex);
1406 event = _lttng_kernel_event_recorder_create(chan, event_param, event_desc, itype);
1407 mutex_unlock(&sessions_mutex);
1408 return event;
1409 }
1410
1411 struct lttng_kernel_event_notifier *lttng_event_notifier_create(
1412 const struct lttng_kernel_event_desc *event_desc,
1413 uint64_t id, uint64_t error_counter_index,
1414 struct lttng_event_notifier_group *event_notifier_group,
1415 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1416 enum lttng_kernel_abi_instrumentation itype)
1417 {
1418 struct lttng_kernel_event_notifier *event_notifier;
1419
1420 mutex_lock(&sessions_mutex);
1421 event_notifier = _lttng_event_notifier_create(event_desc, id,
1422 error_counter_index, event_notifier_group,
1423 event_notifier_param, itype);
1424 mutex_unlock(&sessions_mutex);
1425 return event_notifier;
1426 }
1427
1428 /* Only used for tracepoints for now. */
1429 static
1430 void register_event(struct lttng_kernel_event_recorder *event_recorder)
1431 {
1432 const struct lttng_kernel_event_desc *desc;
1433 int ret = -EINVAL;
1434
1435 if (event_recorder->priv->parent.registered)
1436 return;
1437
1438 desc = event_recorder->priv->parent.desc;
1439 switch (event_recorder->priv->parent.instrumentation) {
1440 case LTTNG_KERNEL_ABI_TRACEPOINT:
1441 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1442 desc->tp_class->probe_callback,
1443 event_recorder);
1444 break;
1445
1446 case LTTNG_KERNEL_ABI_SYSCALL:
1447 ret = lttng_syscall_filter_enable_event(event_recorder->chan, event_recorder);
1448 break;
1449
1450 case LTTNG_KERNEL_ABI_KPROBE:
1451 lttng_fallthrough;
1452 case LTTNG_KERNEL_ABI_UPROBE:
1453 lttng_fallthrough;
1454 case LTTNG_KERNEL_ABI_KRETPROBE:
1455 ret = 0;
1456 break;
1457
1458 case LTTNG_KERNEL_ABI_FUNCTION:
1459 lttng_fallthrough;
1460 case LTTNG_KERNEL_ABI_NOOP:
1461 lttng_fallthrough;
1462 default:
1463 WARN_ON_ONCE(1);
1464 }
1465 if (!ret)
1466 event_recorder->priv->parent.registered = 1;
1467 }
1468
1469 /*
1470 * Only used internally at session destruction.
1471 */
1472 int _lttng_event_unregister(struct lttng_kernel_event_recorder *event_recorder)
1473 {
1474 struct lttng_kernel_event_common_private *event_priv = &event_recorder->priv->parent;
1475 const struct lttng_kernel_event_desc *desc;
1476 int ret = -EINVAL;
1477
1478 if (!event_priv->registered)
1479 return 0;
1480
1481 desc = event_priv->desc;
1482 switch (event_priv->instrumentation) {
1483 case LTTNG_KERNEL_ABI_TRACEPOINT:
1484 ret = lttng_wrapper_tracepoint_probe_unregister(event_priv->desc->event_kname,
1485 event_priv->desc->tp_class->probe_callback,
1486 event_recorder);
1487 break;
1488
1489 case LTTNG_KERNEL_ABI_KPROBE:
1490 lttng_kprobes_unregister_event(event_recorder);
1491 ret = 0;
1492 break;
1493
1494 case LTTNG_KERNEL_ABI_KRETPROBE:
1495 lttng_kretprobes_unregister(event_recorder);
1496 ret = 0;
1497 break;
1498
1499 case LTTNG_KERNEL_ABI_SYSCALL:
1500 ret = lttng_syscall_filter_disable_event(event_recorder->chan, event_recorder);
1501 break;
1502
1503 case LTTNG_KERNEL_ABI_NOOP:
1504 ret = 0;
1505 break;
1506
1507 case LTTNG_KERNEL_ABI_UPROBE:
1508 lttng_uprobes_unregister_event(event_recorder);
1509 ret = 0;
1510 break;
1511
1512 case LTTNG_KERNEL_ABI_FUNCTION:
1513 lttng_fallthrough;
1514 default:
1515 WARN_ON_ONCE(1);
1516 }
1517 if (!ret)
1518 event_priv->registered = 0;
1519 return ret;
1520 }
1521
1522 /* Only used for tracepoints for now. */
1523 static
1524 void register_event_notifier(struct lttng_kernel_event_notifier *event_notifier)
1525 {
1526 const struct lttng_kernel_event_desc *desc;
1527 int ret = -EINVAL;
1528
1529 if (event_notifier->priv->parent.registered)
1530 return;
1531
1532 desc = event_notifier->priv->parent.desc;
1533 switch (event_notifier->priv->parent.instrumentation) {
1534 case LTTNG_KERNEL_ABI_TRACEPOINT:
1535 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1536 desc->tp_class->probe_callback,
1537 event_notifier);
1538 break;
1539
1540 case LTTNG_KERNEL_ABI_SYSCALL:
1541 ret = lttng_syscall_filter_enable_event_notifier(event_notifier);
1542 break;
1543
1544 case LTTNG_KERNEL_ABI_KPROBE:
1545 lttng_fallthrough;
1546 case LTTNG_KERNEL_ABI_UPROBE:
1547 ret = 0;
1548 break;
1549
1550 case LTTNG_KERNEL_ABI_KRETPROBE:
1551 lttng_fallthrough;
1552 case LTTNG_KERNEL_ABI_FUNCTION:
1553 lttng_fallthrough;
1554 case LTTNG_KERNEL_ABI_NOOP:
1555 lttng_fallthrough;
1556 default:
1557 WARN_ON_ONCE(1);
1558 }
1559 if (!ret)
1560 event_notifier->priv->parent.registered = 1;
1561 }
1562
1563 static
1564 int _lttng_event_notifier_unregister(
1565 struct lttng_kernel_event_notifier *event_notifier)
1566 {
1567 const struct lttng_kernel_event_desc *desc;
1568 int ret = -EINVAL;
1569
1570 if (!event_notifier->priv->parent.registered)
1571 return 0;
1572
1573 desc = event_notifier->priv->parent.desc;
1574 switch (event_notifier->priv->parent.instrumentation) {
1575 case LTTNG_KERNEL_ABI_TRACEPOINT:
1576 ret = lttng_wrapper_tracepoint_probe_unregister(event_notifier->priv->parent.desc->event_kname,
1577 event_notifier->priv->parent.desc->tp_class->probe_callback,
1578 event_notifier);
1579 break;
1580
1581 case LTTNG_KERNEL_ABI_KPROBE:
1582 lttng_kprobes_unregister_event_notifier(event_notifier);
1583 ret = 0;
1584 break;
1585
1586 case LTTNG_KERNEL_ABI_UPROBE:
1587 lttng_uprobes_unregister_event_notifier(event_notifier);
1588 ret = 0;
1589 break;
1590
1591 case LTTNG_KERNEL_ABI_SYSCALL:
1592 ret = lttng_syscall_filter_disable_event_notifier(event_notifier);
1593 break;
1594
1595 case LTTNG_KERNEL_ABI_KRETPROBE:
1596 lttng_fallthrough;
1597 case LTTNG_KERNEL_ABI_FUNCTION:
1598 lttng_fallthrough;
1599 case LTTNG_KERNEL_ABI_NOOP:
1600 lttng_fallthrough;
1601 default:
1602 WARN_ON_ONCE(1);
1603 }
1604 if (!ret)
1605 event_notifier->priv->parent.registered = 0;
1606 return ret;
1607 }
1608
1609 /*
1610 * Only used internally at session destruction.
1611 */
1612 static
1613 void _lttng_event_destroy(struct lttng_kernel_event_common *event)
1614 {
1615 struct lttng_kernel_event_common_private *event_priv = event->priv;
1616 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1617
1618 lttng_free_event_filter_runtime(event);
1619 /* Free event enabler refs */
1620 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1621 &event_priv->enablers_ref_head, node)
1622 kfree(enabler_ref);
1623
1624 switch (event->type) {
1625 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1626 {
1627 struct lttng_kernel_event_recorder *event_recorder =
1628 container_of(event, struct lttng_kernel_event_recorder, parent);
1629
1630 switch (event_priv->instrumentation) {
1631 case LTTNG_KERNEL_ABI_TRACEPOINT:
1632 lttng_event_desc_put(event_priv->desc);
1633 break;
1634
1635 case LTTNG_KERNEL_ABI_KPROBE:
1636 module_put(event_priv->desc->owner);
1637 lttng_kprobes_destroy_event_private(event_recorder);
1638 break;
1639
1640 case LTTNG_KERNEL_ABI_KRETPROBE:
1641 module_put(event_priv->desc->owner);
1642 lttng_kretprobes_destroy_private(event_recorder);
1643 break;
1644
1645 case LTTNG_KERNEL_ABI_SYSCALL:
1646 break;
1647
1648 case LTTNG_KERNEL_ABI_UPROBE:
1649 module_put(event_priv->desc->owner);
1650 lttng_uprobes_destroy_event_private(event_recorder);
1651 break;
1652
1653 case LTTNG_KERNEL_ABI_FUNCTION:
1654 lttng_fallthrough;
1655 case LTTNG_KERNEL_ABI_NOOP:
1656 lttng_fallthrough;
1657 default:
1658 WARN_ON_ONCE(1);
1659 }
1660 list_del(&event_recorder->priv->node);
1661 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
1662 kmem_cache_free(event_recorder_cache, event_recorder);
1663 break;
1664 }
1665 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1666 {
1667 struct lttng_kernel_event_notifier *event_notifier =
1668 container_of(event, struct lttng_kernel_event_notifier, parent);
1669
1670 switch (event_notifier->priv->parent.instrumentation) {
1671 case LTTNG_KERNEL_ABI_TRACEPOINT:
1672 lttng_event_desc_put(event_notifier->priv->parent.desc);
1673 break;
1674
1675 case LTTNG_KERNEL_ABI_KPROBE:
1676 module_put(event_notifier->priv->parent.desc->owner);
1677 lttng_kprobes_destroy_event_notifier_private(event_notifier);
1678 break;
1679
1680 case LTTNG_KERNEL_ABI_SYSCALL:
1681 break;
1682
1683 case LTTNG_KERNEL_ABI_UPROBE:
1684 module_put(event_notifier->priv->parent.desc->owner);
1685 lttng_uprobes_destroy_event_notifier_private(event_notifier);
1686 break;
1687
1688 case LTTNG_KERNEL_ABI_KRETPROBE:
1689 lttng_fallthrough;
1690 case LTTNG_KERNEL_ABI_FUNCTION:
1691 lttng_fallthrough;
1692 case LTTNG_KERNEL_ABI_NOOP:
1693 lttng_fallthrough;
1694 default:
1695 WARN_ON_ONCE(1);
1696 }
1697 list_del(&event_notifier->priv->node);
1698 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1699 kmem_cache_free(event_notifier_cache, event_notifier);
1700 break;
1701 }
1702 default:
1703 WARN_ON_ONCE(1);
1704 }
1705 }
1706
1707 struct lttng_kernel_id_tracker *get_tracker(struct lttng_kernel_session *session,
1708 enum tracker_type tracker_type)
1709 {
1710 switch (tracker_type) {
1711 case TRACKER_PID:
1712 return &session->pid_tracker;
1713 case TRACKER_VPID:
1714 return &session->vpid_tracker;
1715 case TRACKER_UID:
1716 return &session->uid_tracker;
1717 case TRACKER_VUID:
1718 return &session->vuid_tracker;
1719 case TRACKER_GID:
1720 return &session->gid_tracker;
1721 case TRACKER_VGID:
1722 return &session->vgid_tracker;
1723 default:
1724 WARN_ON_ONCE(1);
1725 return NULL;
1726 }
1727 }
1728
1729 int lttng_session_track_id(struct lttng_kernel_session *session,
1730 enum tracker_type tracker_type, int id)
1731 {
1732 struct lttng_kernel_id_tracker *tracker;
1733 int ret;
1734
1735 tracker = get_tracker(session, tracker_type);
1736 if (!tracker)
1737 return -EINVAL;
1738 if (id < -1)
1739 return -EINVAL;
1740 mutex_lock(&sessions_mutex);
1741 if (id == -1) {
1742 /* track all ids: destroy tracker. */
1743 lttng_id_tracker_destroy(tracker, true);
1744 ret = 0;
1745 } else {
1746 ret = lttng_id_tracker_add(tracker, id);
1747 }
1748 mutex_unlock(&sessions_mutex);
1749 return ret;
1750 }
1751
1752 int lttng_session_untrack_id(struct lttng_kernel_session *session,
1753 enum tracker_type tracker_type, int id)
1754 {
1755 struct lttng_kernel_id_tracker *tracker;
1756 int ret;
1757
1758 tracker = get_tracker(session, tracker_type);
1759 if (!tracker)
1760 return -EINVAL;
1761 if (id < -1)
1762 return -EINVAL;
1763 mutex_lock(&sessions_mutex);
1764 if (id == -1) {
1765 /* untrack all ids: replace by empty tracker. */
1766 ret = lttng_id_tracker_empty_set(tracker);
1767 } else {
1768 ret = lttng_id_tracker_del(tracker, id);
1769 }
1770 mutex_unlock(&sessions_mutex);
1771 return ret;
1772 }
1773
1774 static
1775 void *id_list_start(struct seq_file *m, loff_t *pos)
1776 {
1777 struct lttng_kernel_id_tracker *id_tracker = m->private;
1778 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1779 struct lttng_id_hash_node *e;
1780 int iter = 0, i;
1781
1782 mutex_lock(&sessions_mutex);
1783 if (id_tracker_p) {
1784 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1785 struct hlist_head *head = &id_tracker_p->id_hash[i];
1786
1787 lttng_hlist_for_each_entry(e, head, hlist) {
1788 if (iter++ >= *pos)
1789 return e;
1790 }
1791 }
1792 } else {
1793 /* ID tracker disabled. */
1794 if (iter >= *pos && iter == 0) {
1795 return id_tracker_p; /* empty tracker */
1796 }
1797 iter++;
1798 }
1799 /* End of list */
1800 return NULL;
1801 }
1802
1803 /* Called with sessions_mutex held. */
1804 static
1805 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1806 {
1807 struct lttng_kernel_id_tracker *id_tracker = m->private;
1808 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1809 struct lttng_id_hash_node *e;
1810 int iter = 0, i;
1811
1812 (*ppos)++;
1813 if (id_tracker_p) {
1814 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1815 struct hlist_head *head = &id_tracker_p->id_hash[i];
1816
1817 lttng_hlist_for_each_entry(e, head, hlist) {
1818 if (iter++ >= *ppos)
1819 return e;
1820 }
1821 }
1822 } else {
1823 /* ID tracker disabled. */
1824 if (iter >= *ppos && iter == 0)
1825 return p; /* empty tracker */
1826 iter++;
1827 }
1828
1829 /* End of list */
1830 return NULL;
1831 }
1832
1833 static
1834 void id_list_stop(struct seq_file *m, void *p)
1835 {
1836 mutex_unlock(&sessions_mutex);
1837 }
1838
1839 static
1840 int id_list_show(struct seq_file *m, void *p)
1841 {
1842 struct lttng_kernel_id_tracker *id_tracker = m->private;
1843 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1844 int id;
1845
1846 if (p == id_tracker_p) {
1847 /* Tracker disabled. */
1848 id = -1;
1849 } else {
1850 const struct lttng_id_hash_node *e = p;
1851
1852 id = lttng_id_tracker_get_node_id(e);
1853 }
1854 switch (id_tracker->priv->tracker_type) {
1855 case TRACKER_PID:
1856 seq_printf(m, "process { pid = %d; };\n", id);
1857 break;
1858 case TRACKER_VPID:
1859 seq_printf(m, "process { vpid = %d; };\n", id);
1860 break;
1861 case TRACKER_UID:
1862 seq_printf(m, "user { uid = %d; };\n", id);
1863 break;
1864 case TRACKER_VUID:
1865 seq_printf(m, "user { vuid = %d; };\n", id);
1866 break;
1867 case TRACKER_GID:
1868 seq_printf(m, "group { gid = %d; };\n", id);
1869 break;
1870 case TRACKER_VGID:
1871 seq_printf(m, "group { vgid = %d; };\n", id);
1872 break;
1873 default:
1874 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1875 }
1876 return 0;
1877 }
1878
1879 static
1880 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1881 .start = id_list_start,
1882 .next = id_list_next,
1883 .stop = id_list_stop,
1884 .show = id_list_show,
1885 };
1886
1887 static
1888 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1889 {
1890 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1891 }
1892
1893 static
1894 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1895 {
1896 struct seq_file *m = file->private_data;
1897 struct lttng_kernel_id_tracker *id_tracker = m->private;
1898 int ret;
1899
1900 WARN_ON_ONCE(!id_tracker);
1901 ret = seq_release(inode, file);
1902 if (!ret)
1903 fput(id_tracker->priv->session->priv->file);
1904 return ret;
1905 }
1906
1907 const struct file_operations lttng_tracker_ids_list_fops = {
1908 .owner = THIS_MODULE,
1909 .open = lttng_tracker_ids_list_open,
1910 .read = seq_read,
1911 .llseek = seq_lseek,
1912 .release = lttng_tracker_ids_list_release,
1913 };
1914
1915 int lttng_session_list_tracker_ids(struct lttng_kernel_session *session,
1916 enum tracker_type tracker_type)
1917 {
1918 struct file *tracker_ids_list_file;
1919 struct seq_file *m;
1920 int file_fd, ret;
1921
1922 file_fd = lttng_get_unused_fd();
1923 if (file_fd < 0) {
1924 ret = file_fd;
1925 goto fd_error;
1926 }
1927
1928 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1929 &lttng_tracker_ids_list_fops,
1930 NULL, O_RDWR);
1931 if (IS_ERR(tracker_ids_list_file)) {
1932 ret = PTR_ERR(tracker_ids_list_file);
1933 goto file_error;
1934 }
1935 if (!atomic_long_add_unless(&session->priv->file->f_count, 1, LONG_MAX)) {
1936 ret = -EOVERFLOW;
1937 goto refcount_error;
1938 }
1939 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1940 if (ret < 0)
1941 goto open_error;
1942 m = tracker_ids_list_file->private_data;
1943
1944 m->private = get_tracker(session, tracker_type);
1945 BUG_ON(!m->private);
1946 fd_install(file_fd, tracker_ids_list_file);
1947
1948 return file_fd;
1949
1950 open_error:
1951 atomic_long_dec(&session->priv->file->f_count);
1952 refcount_error:
1953 fput(tracker_ids_list_file);
1954 file_error:
1955 put_unused_fd(file_fd);
1956 fd_error:
1957 return ret;
1958 }
1959
1960 /*
1961 * Enabler management.
1962 */
1963 static
1964 int lttng_match_enabler_star_glob(const char *desc_name,
1965 const char *pattern)
1966 {
1967 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1968 desc_name, LTTNG_SIZE_MAX))
1969 return 0;
1970 return 1;
1971 }
1972
1973 static
1974 int lttng_match_enabler_name(const char *desc_name,
1975 const char *name)
1976 {
1977 if (strcmp(desc_name, name))
1978 return 0;
1979 return 1;
1980 }
1981
1982 int lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
1983 struct lttng_enabler *enabler)
1984 {
1985 const char *desc_name, *enabler_name;
1986 bool compat = false, entry = false;
1987
1988 enabler_name = enabler->event_param.name;
1989 switch (enabler->event_param.instrumentation) {
1990 case LTTNG_KERNEL_ABI_TRACEPOINT:
1991 desc_name = desc->event_name;
1992 switch (enabler->format_type) {
1993 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1994 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1995 case LTTNG_ENABLER_FORMAT_NAME:
1996 return lttng_match_enabler_name(desc_name, enabler_name);
1997 default:
1998 return -EINVAL;
1999 }
2000 break;
2001
2002 case LTTNG_KERNEL_ABI_SYSCALL:
2003 desc_name = desc->event_name;
2004 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
2005 desc_name += strlen("compat_");
2006 compat = true;
2007 }
2008 if (!strncmp(desc_name, "syscall_exit_",
2009 strlen("syscall_exit_"))) {
2010 desc_name += strlen("syscall_exit_");
2011 } else if (!strncmp(desc_name, "syscall_entry_",
2012 strlen("syscall_entry_"))) {
2013 desc_name += strlen("syscall_entry_");
2014 entry = true;
2015 } else {
2016 WARN_ON_ONCE(1);
2017 return -EINVAL;
2018 }
2019 switch (enabler->event_param.u.syscall.entryexit) {
2020 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
2021 break;
2022 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
2023 if (!entry)
2024 return 0;
2025 break;
2026 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
2027 if (entry)
2028 return 0;
2029 break;
2030 default:
2031 return -EINVAL;
2032 }
2033 switch (enabler->event_param.u.syscall.abi) {
2034 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
2035 break;
2036 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
2037 if (compat)
2038 return 0;
2039 break;
2040 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
2041 if (!compat)
2042 return 0;
2043 break;
2044 default:
2045 return -EINVAL;
2046 }
2047 switch (enabler->event_param.u.syscall.match) {
2048 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
2049 switch (enabler->format_type) {
2050 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2051 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2052 case LTTNG_ENABLER_FORMAT_NAME:
2053 return lttng_match_enabler_name(desc_name, enabler_name);
2054 default:
2055 return -EINVAL;
2056 }
2057 break;
2058 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
2059 return -EINVAL; /* Not implemented. */
2060 default:
2061 return -EINVAL;
2062 }
2063 break;
2064
2065 default:
2066 WARN_ON_ONCE(1);
2067 return -EINVAL;
2068 }
2069 }
2070
2071 static
2072 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
2073 struct lttng_kernel_event_recorder *event_recorder)
2074 {
2075 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
2076 event_enabler);
2077
2078 if (base_enabler->event_param.instrumentation != event_recorder->priv->parent.instrumentation)
2079 return 0;
2080 if (lttng_desc_match_enabler(event_recorder->priv->parent.desc, base_enabler)
2081 && event_recorder->chan == event_enabler->chan)
2082 return 1;
2083 else
2084 return 0;
2085 }
2086
2087 static
2088 int lttng_event_notifier_enabler_match_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler,
2089 struct lttng_kernel_event_notifier *event_notifier)
2090 {
2091 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(
2092 event_notifier_enabler);
2093
2094 if (base_enabler->event_param.instrumentation != event_notifier->priv->parent.instrumentation)
2095 return 0;
2096 if (lttng_desc_match_enabler(event_notifier->priv->parent.desc, base_enabler)
2097 && event_notifier->priv->group == event_notifier_enabler->group
2098 && event_notifier->priv->parent.user_token == event_notifier_enabler->base.user_token)
2099 return 1;
2100 else
2101 return 0;
2102 }
2103
2104 static
2105 struct lttng_enabler_ref *lttng_enabler_ref(
2106 struct list_head *enablers_ref_list,
2107 struct lttng_enabler *enabler)
2108 {
2109 struct lttng_enabler_ref *enabler_ref;
2110
2111 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2112 if (enabler_ref->ref == enabler)
2113 return enabler_ref;
2114 }
2115 return NULL;
2116 }
2117
2118 static
2119 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
2120 {
2121 struct lttng_kernel_session *session = event_enabler->chan->parent.session;
2122 struct lttng_kernel_probe_desc *probe_desc;
2123 const struct lttng_kernel_event_desc *desc;
2124 int i;
2125 struct list_head *probe_list;
2126
2127 probe_list = lttng_get_probe_list_head();
2128 /*
2129 * For each probe event, if we find that a probe event matches
2130 * our enabler, create an associated lttng_event if not
2131 * already present.
2132 */
2133 list_for_each_entry(probe_desc, probe_list, head) {
2134 for (i = 0; i < probe_desc->nr_events; i++) {
2135 int found = 0;
2136 struct hlist_head *head;
2137 struct lttng_kernel_event_recorder_private *event_recorder_private;
2138 struct lttng_kernel_event_recorder *event_recorder;
2139
2140 desc = probe_desc->event_desc[i];
2141 if (!lttng_desc_match_enabler(desc,
2142 lttng_event_enabler_as_enabler(event_enabler)))
2143 continue;
2144
2145 /*
2146 * Check if already created.
2147 */
2148 head = utils_borrow_hash_table_bucket(
2149 session->priv->events_ht.table, LTTNG_EVENT_HT_SIZE,
2150 desc->event_name);
2151 lttng_hlist_for_each_entry(event_recorder_private, head, hlist) {
2152 if (event_recorder_private->parent.desc == desc
2153 && event_recorder_private->pub->chan == event_enabler->chan)
2154 found = 1;
2155 }
2156 if (found)
2157 continue;
2158
2159 /*
2160 * We need to create an event for this
2161 * event probe.
2162 */
2163 event_recorder = _lttng_kernel_event_recorder_create(event_enabler->chan,
2164 NULL, desc, LTTNG_KERNEL_ABI_TRACEPOINT);
2165 if (!event_recorder) {
2166 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2167 probe_desc->event_desc[i]->event_name);
2168 }
2169 }
2170 }
2171 }
2172
2173 static
2174 void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2175 {
2176 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2177 struct lttng_kernel_probe_desc *probe_desc;
2178 const struct lttng_kernel_event_desc *desc;
2179 int i;
2180 struct list_head *probe_list;
2181
2182 probe_list = lttng_get_probe_list_head();
2183 /*
2184 * For each probe event, if we find that a probe event matches
2185 * our enabler, create an associated lttng_event_notifier if not
2186 * already present.
2187 */
2188 list_for_each_entry(probe_desc, probe_list, head) {
2189 for (i = 0; i < probe_desc->nr_events; i++) {
2190 int found = 0;
2191 struct hlist_head *head;
2192 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2193 struct lttng_kernel_event_notifier *event_notifier;
2194
2195 desc = probe_desc->event_desc[i];
2196 if (!lttng_desc_match_enabler(desc,
2197 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
2198 continue;
2199
2200 /*
2201 * Check if already created.
2202 */
2203 head = utils_borrow_hash_table_bucket(
2204 event_notifier_group->event_notifiers_ht.table,
2205 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->event_name);
2206 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
2207 if (event_notifier_priv->parent.desc == desc
2208 && event_notifier_priv->parent.user_token == event_notifier_enabler->base.user_token)
2209 found = 1;
2210 }
2211 if (found)
2212 continue;
2213
2214 /*
2215 * We need to create a event_notifier for this event probe.
2216 */
2217 event_notifier = _lttng_event_notifier_create(desc,
2218 event_notifier_enabler->base.user_token,
2219 event_notifier_enabler->error_counter_index,
2220 event_notifier_group, NULL,
2221 LTTNG_KERNEL_ABI_TRACEPOINT);
2222 if (IS_ERR(event_notifier)) {
2223 printk(KERN_INFO "Unable to create event_notifier %s\n",
2224 probe_desc->event_desc[i]->event_name);
2225 }
2226 }
2227 }
2228 }
2229
2230 static
2231 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
2232 {
2233 int ret;
2234
2235 ret = lttng_syscalls_register_event(event_enabler);
2236 WARN_ON_ONCE(ret);
2237 }
2238
2239 static
2240 void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2241 {
2242 int ret;
2243
2244 ret = lttng_syscalls_register_event_notifier(event_notifier_enabler);
2245 WARN_ON_ONCE(ret);
2246 ret = lttng_syscalls_create_matching_event_notifiers(event_notifier_enabler);
2247 WARN_ON_ONCE(ret);
2248 }
2249
2250 /*
2251 * Create struct lttng_kernel_event_recorder if it is missing and present in the list of
2252 * tracepoint probes.
2253 * Should be called with sessions mutex held.
2254 */
2255 static
2256 void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
2257 {
2258 switch (event_enabler->base.event_param.instrumentation) {
2259 case LTTNG_KERNEL_ABI_TRACEPOINT:
2260 lttng_create_tracepoint_event_if_missing(event_enabler);
2261 break;
2262
2263 case LTTNG_KERNEL_ABI_SYSCALL:
2264 lttng_create_syscall_event_if_missing(event_enabler);
2265 break;
2266
2267 default:
2268 WARN_ON_ONCE(1);
2269 break;
2270 }
2271 }
2272
2273 /*
2274 * Create events associated with an event_enabler (if not already present),
2275 * and add backward reference from the event to the enabler.
2276 * Should be called with sessions mutex held.
2277 */
2278 static
2279 int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
2280 {
2281 struct lttng_kernel_channel_buffer *chan = event_enabler->chan;
2282 struct lttng_kernel_session *session = event_enabler->chan->parent.session;
2283 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
2284 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2285
2286 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2287 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2288 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2289 !strcmp(base_enabler->event_param.name, "*")) {
2290 int enabled = base_enabler->enabled;
2291 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2292
2293 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2294 WRITE_ONCE(chan->priv->parent.syscall_all_entry, enabled);
2295
2296 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2297 WRITE_ONCE(chan->priv->parent.syscall_all_exit, enabled);
2298 }
2299
2300 /* First ensure that probe events are created for this enabler. */
2301 lttng_create_event_if_missing(event_enabler);
2302
2303 /* For each event matching event_enabler in session event list. */
2304 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
2305 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2306 struct lttng_enabler_ref *enabler_ref;
2307
2308 if (!lttng_event_enabler_match_event(event_enabler, event_recorder))
2309 continue;
2310 enabler_ref = lttng_enabler_ref(&event_recorder_priv->parent.enablers_ref_head,
2311 lttng_event_enabler_as_enabler(event_enabler));
2312 if (!enabler_ref) {
2313 /*
2314 * If no backward ref, create it.
2315 * Add backward ref from event to event_enabler.
2316 */
2317 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2318 if (!enabler_ref)
2319 return -ENOMEM;
2320 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
2321 list_add(&enabler_ref->node,
2322 &event_recorder_priv->parent.enablers_ref_head);
2323 }
2324
2325 /*
2326 * Link filter bytecodes if not linked yet.
2327 */
2328 lttng_enabler_link_bytecode(event_recorder_priv->parent.desc,
2329 lttng_static_ctx,
2330 &event_recorder_priv->parent.filter_bytecode_runtime_head,
2331 &lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
2332 }
2333 return 0;
2334 }
2335
2336 /*
2337 * Create struct lttng_kernel_event_notifier if it is missing and present in the list of
2338 * tracepoint probes.
2339 * Should be called with sessions mutex held.
2340 */
2341 static
2342 void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2343 {
2344 switch (event_notifier_enabler->base.event_param.instrumentation) {
2345 case LTTNG_KERNEL_ABI_TRACEPOINT:
2346 lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
2347 break;
2348
2349 case LTTNG_KERNEL_ABI_SYSCALL:
2350 lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler);
2351 break;
2352
2353 default:
2354 WARN_ON_ONCE(1);
2355 break;
2356 }
2357 }
2358
2359 /*
2360 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2361 */
2362 static
2363 int lttng_event_notifier_enabler_ref_event_notifiers(
2364 struct lttng_event_notifier_enabler *event_notifier_enabler)
2365 {
2366 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2367 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2368 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2369
2370 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2371 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2372 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2373 !strcmp(base_enabler->event_param.name, "*")) {
2374
2375 int enabled = base_enabler->enabled;
2376 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2377
2378 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2379 WRITE_ONCE(event_notifier_group->syscall_all_entry, enabled);
2380
2381 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2382 WRITE_ONCE(event_notifier_group->syscall_all_exit, enabled);
2383
2384 }
2385
2386 /* First ensure that probe event_notifiers are created for this enabler. */
2387 lttng_create_event_notifier_if_missing(event_notifier_enabler);
2388
2389 /* Link the created event_notifier with its associated enabler. */
2390 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2391 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2392 struct lttng_enabler_ref *enabler_ref;
2393
2394 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier))
2395 continue;
2396
2397 enabler_ref = lttng_enabler_ref(&event_notifier_priv->parent.enablers_ref_head,
2398 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2399 if (!enabler_ref) {
2400 /*
2401 * If no backward ref, create it.
2402 * Add backward ref from event_notifier to enabler.
2403 */
2404 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2405 if (!enabler_ref)
2406 return -ENOMEM;
2407
2408 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2409 event_notifier_enabler);
2410 list_add(&enabler_ref->node,
2411 &event_notifier_priv->parent.enablers_ref_head);
2412 }
2413
2414 /*
2415 * Link filter bytecodes if not linked yet.
2416 */
2417 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2418 lttng_static_ctx, &event_notifier_priv->parent.filter_bytecode_runtime_head,
2419 &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
2420
2421 /* Link capture bytecodes if not linked yet. */
2422 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2423 lttng_static_ctx, &event_notifier_priv->capture_bytecode_runtime_head,
2424 &event_notifier_enabler->capture_bytecode_head);
2425
2426 event_notifier_priv->num_captures = event_notifier_enabler->num_captures;
2427 }
2428 return 0;
2429 }
2430
2431 /*
2432 * Called at module load: connect the probe on all enablers matching
2433 * this event.
2434 * Called with sessions lock held.
2435 */
2436 int lttng_fix_pending_events(void)
2437 {
2438 struct lttng_kernel_session_private *session_priv;
2439
2440 list_for_each_entry(session_priv, &sessions, list)
2441 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2442 return 0;
2443 }
2444
2445 static bool lttng_event_notifier_group_has_active_event_notifiers(
2446 struct lttng_event_notifier_group *event_notifier_group)
2447 {
2448 struct lttng_event_notifier_enabler *event_notifier_enabler;
2449
2450 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2451 node) {
2452 if (event_notifier_enabler->base.enabled)
2453 return true;
2454 }
2455 return false;
2456 }
2457
2458 bool lttng_event_notifier_active(void)
2459 {
2460 struct lttng_event_notifier_group *event_notifier_group;
2461
2462 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2463 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2464 return true;
2465 }
2466 return false;
2467 }
2468
2469 int lttng_fix_pending_event_notifiers(void)
2470 {
2471 struct lttng_event_notifier_group *event_notifier_group;
2472
2473 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2474 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2475 return 0;
2476 }
2477
2478 struct lttng_event_enabler *lttng_event_enabler_create(
2479 enum lttng_enabler_format_type format_type,
2480 struct lttng_kernel_abi_event *event_param,
2481 struct lttng_kernel_channel_buffer *chan)
2482 {
2483 struct lttng_event_enabler *event_enabler;
2484
2485 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2486 if (!event_enabler)
2487 return NULL;
2488 event_enabler->base.format_type = format_type;
2489 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2490 memcpy(&event_enabler->base.event_param, event_param,
2491 sizeof(event_enabler->base.event_param));
2492 event_enabler->chan = chan;
2493 /* ctx left NULL */
2494 event_enabler->base.enabled = 0;
2495 mutex_lock(&sessions_mutex);
2496 list_add(&event_enabler->node, &event_enabler->chan->parent.session->priv->enablers_head);
2497 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2498 mutex_unlock(&sessions_mutex);
2499 return event_enabler;
2500 }
2501
2502 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2503 {
2504 mutex_lock(&sessions_mutex);
2505 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2506 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2507 mutex_unlock(&sessions_mutex);
2508 return 0;
2509 }
2510
2511 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2512 {
2513 mutex_lock(&sessions_mutex);
2514 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2515 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2516 mutex_unlock(&sessions_mutex);
2517 return 0;
2518 }
2519
2520 static
2521 int lttng_enabler_attach_filter_bytecode(struct lttng_enabler *enabler,
2522 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2523 {
2524 struct lttng_kernel_bytecode_node *bytecode_node;
2525 uint32_t bytecode_len;
2526 int ret;
2527
2528 ret = get_user(bytecode_len, &bytecode->len);
2529 if (ret)
2530 return ret;
2531 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2532 GFP_KERNEL);
2533 if (!bytecode_node)
2534 return -ENOMEM;
2535 ret = copy_from_user(&bytecode_node->bc, bytecode,
2536 sizeof(*bytecode) + bytecode_len);
2537 if (ret)
2538 goto error_free;
2539
2540 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2541 bytecode_node->enabler = enabler;
2542 /* Enforce length based on allocated size */
2543 bytecode_node->bc.len = bytecode_len;
2544 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2545
2546 return 0;
2547
2548 error_free:
2549 lttng_kvfree(bytecode_node);
2550 return ret;
2551 }
2552
2553 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler *event_enabler,
2554 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2555 {
2556 int ret;
2557 ret = lttng_enabler_attach_filter_bytecode(
2558 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2559 if (ret)
2560 goto error;
2561
2562 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2563 return 0;
2564
2565 error:
2566 return ret;
2567 }
2568
2569 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2570 struct lttng_kernel_abi_event_callsite __user *callsite)
2571 {
2572
2573 switch (event->priv->instrumentation) {
2574 case LTTNG_KERNEL_ABI_UPROBE:
2575 return lttng_uprobes_event_add_callsite(event, callsite);
2576 default:
2577 return -EINVAL;
2578 }
2579 }
2580
2581 static
2582 void lttng_enabler_destroy(struct lttng_enabler *enabler)
2583 {
2584 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2585
2586 /* Destroy filter bytecode */
2587 list_for_each_entry_safe(filter_node, tmp_filter_node,
2588 &enabler->filter_bytecode_head, node) {
2589 lttng_kvfree(filter_node);
2590 }
2591 }
2592
2593 static
2594 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2595 {
2596 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2597
2598 list_del(&event_enabler->node);
2599 kfree(event_enabler);
2600 }
2601
2602 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2603 struct lttng_event_notifier_group *event_notifier_group,
2604 enum lttng_enabler_format_type format_type,
2605 struct lttng_kernel_abi_event_notifier *event_notifier_param)
2606 {
2607 struct lttng_event_notifier_enabler *event_notifier_enabler;
2608
2609 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2610 if (!event_notifier_enabler)
2611 return NULL;
2612
2613 event_notifier_enabler->base.format_type = format_type;
2614 INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
2615 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2616
2617 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2618 event_notifier_enabler->num_captures = 0;
2619
2620 memcpy(&event_notifier_enabler->base.event_param, &event_notifier_param->event,
2621 sizeof(event_notifier_enabler->base.event_param));
2622
2623 event_notifier_enabler->base.enabled = 0;
2624 event_notifier_enabler->base.user_token = event_notifier_param->event.token;
2625 event_notifier_enabler->group = event_notifier_group;
2626
2627 mutex_lock(&sessions_mutex);
2628 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2629 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2630
2631 mutex_unlock(&sessions_mutex);
2632
2633 return event_notifier_enabler;
2634 }
2635
2636 int lttng_event_notifier_enabler_enable(
2637 struct lttng_event_notifier_enabler *event_notifier_enabler)
2638 {
2639 mutex_lock(&sessions_mutex);
2640 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2641 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2642 mutex_unlock(&sessions_mutex);
2643 return 0;
2644 }
2645
2646 int lttng_event_notifier_enabler_disable(
2647 struct lttng_event_notifier_enabler *event_notifier_enabler)
2648 {
2649 mutex_lock(&sessions_mutex);
2650 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2651 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2652 mutex_unlock(&sessions_mutex);
2653 return 0;
2654 }
2655
2656 int lttng_event_notifier_enabler_attach_filter_bytecode(
2657 struct lttng_event_notifier_enabler *event_notifier_enabler,
2658 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2659 {
2660 int ret;
2661
2662 ret = lttng_enabler_attach_filter_bytecode(
2663 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
2664 bytecode);
2665 if (ret)
2666 goto error;
2667
2668 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2669 return 0;
2670
2671 error:
2672 return ret;
2673 }
2674
2675 int lttng_event_notifier_enabler_attach_capture_bytecode(
2676 struct lttng_event_notifier_enabler *event_notifier_enabler,
2677 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2678 {
2679 struct lttng_kernel_bytecode_node *bytecode_node;
2680 struct lttng_enabler *enabler =
2681 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2682 uint32_t bytecode_len;
2683 int ret;
2684
2685 ret = get_user(bytecode_len, &bytecode->len);
2686 if (ret)
2687 return ret;
2688
2689 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2690 GFP_KERNEL);
2691 if (!bytecode_node)
2692 return -ENOMEM;
2693
2694 ret = copy_from_user(&bytecode_node->bc, bytecode,
2695 sizeof(*bytecode) + bytecode_len);
2696 if (ret)
2697 goto error_free;
2698
2699 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2700 bytecode_node->enabler = enabler;
2701
2702 /* Enforce length based on allocated size */
2703 bytecode_node->bc.len = bytecode_len;
2704 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2705
2706 event_notifier_enabler->num_captures++;
2707
2708 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2709 goto end;
2710
2711 error_free:
2712 lttng_kvfree(bytecode_node);
2713 end:
2714 return ret;
2715 }
2716
2717 static
2718 void lttng_event_notifier_enabler_destroy(
2719 struct lttng_event_notifier_enabler *event_notifier_enabler)
2720 {
2721 if (!event_notifier_enabler) {
2722 return;
2723 }
2724
2725 list_del(&event_notifier_enabler->node);
2726
2727 lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2728 kfree(event_notifier_enabler);
2729 }
2730
2731 /*
2732 * lttng_session_sync_event_enablers should be called just before starting a
2733 * session.
2734 * Should be called with sessions mutex held.
2735 */
2736 static
2737 void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2738 {
2739 struct lttng_event_enabler *event_enabler;
2740 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2741
2742 list_for_each_entry(event_enabler, &session->priv->enablers_head, node)
2743 lttng_event_enabler_ref_events(event_enabler);
2744 /*
2745 * For each event, if at least one of its enablers is enabled,
2746 * and its channel and session transient states are enabled, we
2747 * enable the event, else we disable it.
2748 */
2749 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
2750 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2751 struct lttng_enabler_ref *enabler_ref;
2752 struct lttng_kernel_bytecode_runtime *runtime;
2753 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2754 int nr_filters = 0;
2755
2756 switch (event_recorder_priv->parent.instrumentation) {
2757 case LTTNG_KERNEL_ABI_TRACEPOINT:
2758 lttng_fallthrough;
2759 case LTTNG_KERNEL_ABI_SYSCALL:
2760 /* Enable events */
2761 list_for_each_entry(enabler_ref,
2762 &event_recorder_priv->parent.enablers_ref_head, node) {
2763 if (enabler_ref->ref->enabled) {
2764 enabled = 1;
2765 break;
2766 }
2767 }
2768 break;
2769
2770 default:
2771 /* Not handled with lazy sync. */
2772 continue;
2773 }
2774 /*
2775 * Enabled state is based on union of enablers, with
2776 * intesection of session and channel transient enable
2777 * states.
2778 */
2779 enabled = enabled && session->priv->tstate && event_recorder->chan->priv->parent.tstate;
2780
2781 WRITE_ONCE(event_recorder->parent.enabled, enabled);
2782 /*
2783 * Sync tracepoint registration with event enabled
2784 * state.
2785 */
2786 if (enabled) {
2787 register_event(event_recorder);
2788 } else {
2789 _lttng_event_unregister(event_recorder);
2790 }
2791
2792 /* Check if has enablers without bytecode enabled */
2793 list_for_each_entry(enabler_ref,
2794 &event_recorder_priv->parent.enablers_ref_head, node) {
2795 if (enabler_ref->ref->enabled
2796 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2797 has_enablers_without_filter_bytecode = 1;
2798 break;
2799 }
2800 }
2801 event_recorder_priv->parent.has_enablers_without_filter_bytecode =
2802 has_enablers_without_filter_bytecode;
2803
2804 /* Enable filters */
2805 list_for_each_entry(runtime,
2806 &event_recorder_priv->parent.filter_bytecode_runtime_head, node) {
2807 lttng_bytecode_sync_state(runtime);
2808 nr_filters++;
2809 }
2810 WRITE_ONCE(event_recorder_priv->parent.pub->eval_filter,
2811 !(has_enablers_without_filter_bytecode || !nr_filters));
2812 }
2813 }
2814
2815 /*
2816 * Apply enablers to session events, adding events to session if need
2817 * be. It is required after each modification applied to an active
2818 * session, and right before session "start".
2819 * "lazy" sync means we only sync if required.
2820 * Should be called with sessions mutex held.
2821 */
2822 static
2823 void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2824 {
2825 /* We can skip if session is not active */
2826 if (!session->active)
2827 return;
2828 lttng_session_sync_event_enablers(session);
2829 }
2830
2831 static
2832 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2833 {
2834 struct lttng_event_notifier_enabler *event_notifier_enabler;
2835 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2836
2837 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2838 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2839
2840 /*
2841 * For each event_notifier, if at least one of its enablers is enabled,
2842 * we enable the event_notifier, else we disable it.
2843 */
2844 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2845 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2846 struct lttng_enabler_ref *enabler_ref;
2847 struct lttng_kernel_bytecode_runtime *runtime;
2848 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2849 int nr_filters = 0, nr_captures = 0;
2850
2851 switch (event_notifier_priv->parent.instrumentation) {
2852 case LTTNG_KERNEL_ABI_TRACEPOINT:
2853 lttng_fallthrough;
2854 case LTTNG_KERNEL_ABI_SYSCALL:
2855 /* Enable event_notifiers */
2856 list_for_each_entry(enabler_ref,
2857 &event_notifier_priv->parent.enablers_ref_head, node) {
2858 if (enabler_ref->ref->enabled) {
2859 enabled = 1;
2860 break;
2861 }
2862 }
2863 break;
2864
2865 default:
2866 /* Not handled with sync. */
2867 continue;
2868 }
2869
2870 WRITE_ONCE(event_notifier->parent.enabled, enabled);
2871 /*
2872 * Sync tracepoint registration with event_notifier enabled
2873 * state.
2874 */
2875 if (enabled) {
2876 if (!event_notifier_priv->parent.registered)
2877 register_event_notifier(event_notifier);
2878 } else {
2879 if (event_notifier_priv->parent.registered)
2880 _lttng_event_notifier_unregister(event_notifier);
2881 }
2882
2883 /* Check if has enablers without bytecode enabled */
2884 list_for_each_entry(enabler_ref,
2885 &event_notifier_priv->parent.enablers_ref_head, node) {
2886 if (enabler_ref->ref->enabled
2887 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2888 has_enablers_without_filter_bytecode = 1;
2889 break;
2890 }
2891 }
2892 event_notifier_priv->parent.has_enablers_without_filter_bytecode =
2893 has_enablers_without_filter_bytecode;
2894
2895 /* Enable filters */
2896 list_for_each_entry(runtime,
2897 &event_notifier_priv->parent.filter_bytecode_runtime_head, node) {
2898 lttng_bytecode_sync_state(runtime);
2899 nr_filters++;
2900 }
2901 WRITE_ONCE(event_notifier_priv->parent.pub->eval_filter,
2902 !(has_enablers_without_filter_bytecode || !nr_filters));
2903
2904 /* Enable captures */
2905 list_for_each_entry(runtime,
2906 &event_notifier_priv->capture_bytecode_runtime_head, node) {
2907 lttng_bytecode_sync_state(runtime);
2908 nr_captures++;
2909 }
2910 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2911 }
2912 }
2913
2914 /*
2915 * Serialize at most one packet worth of metadata into a metadata
2916 * channel.
2917 * We grab the metadata cache mutex to get exclusive access to our metadata
2918 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2919 * allows us to do racy operations such as looking for remaining space left in
2920 * packet and write, since mutual exclusion protects us from concurrent writes.
2921 * Mutual exclusion on the metadata cache allow us to read the cache content
2922 * without racing against reallocation of the cache by updates.
2923 * Returns the number of bytes written in the channel, 0 if no data
2924 * was written and a negative value on error.
2925 */
2926 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2927 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2928 {
2929 struct lttng_kernel_ring_buffer_ctx ctx;
2930 int ret = 0;
2931 size_t len, reserve_len;
2932
2933 /*
2934 * Ensure we support mutiple get_next / put sequences followed by
2935 * put_next. The metadata cache lock protects reading the metadata
2936 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2937 * "flush" operations on the buffer invoked by different processes.
2938 * Moreover, since the metadata cache memory can be reallocated, we
2939 * need to have exclusive access against updates even though we only
2940 * read it.
2941 */
2942 mutex_lock(&stream->metadata_cache->lock);
2943 WARN_ON(stream->metadata_in < stream->metadata_out);
2944 if (stream->metadata_in != stream->metadata_out)
2945 goto end;
2946
2947 /* Metadata regenerated, change the version. */
2948 if (stream->metadata_cache->version != stream->version)
2949 stream->version = stream->metadata_cache->version;
2950
2951 len = stream->metadata_cache->metadata_written -
2952 stream->metadata_in;
2953 if (!len)
2954 goto end;
2955 reserve_len = min_t(size_t,
2956 stream->transport->ops.priv->packet_avail_size(chan),
2957 len);
2958 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2959 sizeof(char), NULL);
2960 /*
2961 * If reservation failed, return an error to the caller.
2962 */
2963 ret = stream->transport->ops.event_reserve(&ctx);
2964 if (ret != 0) {
2965 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2966 stream->coherent = false;
2967 goto end;
2968 }
2969 stream->transport->ops.event_write(&ctx,
2970 stream->metadata_cache->data + stream->metadata_in,
2971 reserve_len, 1);
2972 stream->transport->ops.event_commit(&ctx);
2973 stream->metadata_in += reserve_len;
2974 if (reserve_len < len)
2975 stream->coherent = false;
2976 else
2977 stream->coherent = true;
2978 ret = reserve_len;
2979
2980 end:
2981 if (coherent)
2982 *coherent = stream->coherent;
2983 mutex_unlock(&stream->metadata_cache->lock);
2984 return ret;
2985 }
2986
2987 static
2988 void lttng_metadata_begin(struct lttng_kernel_session *session)
2989 {
2990 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
2991 mutex_lock(&session->priv->metadata_cache->lock);
2992 }
2993
2994 static
2995 void lttng_metadata_end(struct lttng_kernel_session *session)
2996 {
2997 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2998 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
2999 struct lttng_metadata_stream *stream;
3000
3001 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
3002 wake_up_interruptible(&stream->read_wait);
3003 mutex_unlock(&session->priv->metadata_cache->lock);
3004 }
3005 }
3006
3007 /*
3008 * Write the metadata to the metadata cache.
3009 * Must be called with sessions_mutex held.
3010 * The metadata cache lock protects us from concurrent read access from
3011 * thread outputting metadata content to ring buffer.
3012 * The content of the printf is printed as a single atomic metadata
3013 * transaction.
3014 */
3015 int lttng_metadata_printf(struct lttng_kernel_session *session,
3016 const char *fmt, ...)
3017 {
3018 char *str;
3019 size_t len;
3020 va_list ap;
3021
3022 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
3023
3024 va_start(ap, fmt);
3025 str = kvasprintf(GFP_KERNEL, fmt, ap);
3026 va_end(ap);
3027 if (!str)
3028 return -ENOMEM;
3029
3030 len = strlen(str);
3031 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
3032 if (session->priv->metadata_cache->metadata_written + len >
3033 session->priv->metadata_cache->cache_alloc) {
3034 char *tmp_cache_realloc;
3035 unsigned int tmp_cache_alloc_size;
3036
3037 tmp_cache_alloc_size = max_t(unsigned int,
3038 session->priv->metadata_cache->cache_alloc + len,
3039 session->priv->metadata_cache->cache_alloc << 1);
3040 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
3041 if (!tmp_cache_realloc)
3042 goto err;
3043 if (session->priv->metadata_cache->data) {
3044 memcpy(tmp_cache_realloc,
3045 session->priv->metadata_cache->data,
3046 session->priv->metadata_cache->cache_alloc);
3047 vfree(session->priv->metadata_cache->data);
3048 }
3049
3050 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
3051 session->priv->metadata_cache->data = tmp_cache_realloc;
3052 }
3053 memcpy(session->priv->metadata_cache->data +
3054 session->priv->metadata_cache->metadata_written,
3055 str, len);
3056 session->priv->metadata_cache->metadata_written += len;
3057 kfree(str);
3058
3059 return 0;
3060
3061 err:
3062 kfree(str);
3063 return -ENOMEM;
3064 }
3065
3066 static
3067 int print_tabs(struct lttng_kernel_session *session, size_t nesting)
3068 {
3069 size_t i;
3070
3071 for (i = 0; i < nesting; i++) {
3072 int ret;
3073
3074 ret = lttng_metadata_printf(session, " ");
3075 if (ret) {
3076 return ret;
3077 }
3078 }
3079 return 0;
3080 }
3081
3082 static
3083 int lttng_field_name_statedump(struct lttng_kernel_session *session,
3084 const struct lttng_kernel_event_field *field,
3085 size_t nesting)
3086 {
3087 return lttng_metadata_printf(session, " _%s;\n", field->name);
3088 }
3089
3090 static
3091 int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
3092 const struct lttng_kernel_type_integer *type,
3093 enum lttng_kernel_string_encoding parent_encoding,
3094 size_t nesting)
3095 {
3096 int ret;
3097
3098 ret = print_tabs(session, nesting);
3099 if (ret)
3100 return ret;
3101 ret = lttng_metadata_printf(session,
3102 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
3103 type->size,
3104 type->alignment,
3105 type->signedness,
3106 (parent_encoding == lttng_kernel_string_encoding_none)
3107 ? "none"
3108 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
3109 ? "UTF8"
3110 : "ASCII",
3111 type->base,
3112 #if __BYTE_ORDER == __BIG_ENDIAN
3113 type->reverse_byte_order ? " byte_order = le;" : ""
3114 #else
3115 type->reverse_byte_order ? " byte_order = be;" : ""
3116 #endif
3117 );
3118 return ret;
3119 }
3120
3121 /*
3122 * Must be called with sessions_mutex held.
3123 */
3124 static
3125 int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
3126 const struct lttng_kernel_type_struct *type,
3127 size_t nesting)
3128 {
3129 const char *prev_field_name = NULL;
3130 int ret;
3131 uint32_t i, nr_fields;
3132 unsigned int alignment;
3133
3134 ret = print_tabs(session, nesting);
3135 if (ret)
3136 return ret;
3137 ret = lttng_metadata_printf(session,
3138 "struct {\n");
3139 if (ret)
3140 return ret;
3141 nr_fields = type->nr_fields;
3142 for (i = 0; i < nr_fields; i++) {
3143 const struct lttng_kernel_event_field *iter_field;
3144
3145 iter_field = type->fields[i];
3146 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
3147 if (ret)
3148 return ret;
3149 }
3150 ret = print_tabs(session, nesting);
3151 if (ret)
3152 return ret;
3153 alignment = type->alignment;
3154 if (alignment) {
3155 ret = lttng_metadata_printf(session,
3156 "} align(%u)",
3157 alignment);
3158 } else {
3159 ret = lttng_metadata_printf(session,
3160 "}");
3161 }
3162 return ret;
3163 }
3164
3165 /*
3166 * Must be called with sessions_mutex held.
3167 */
3168 static
3169 int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
3170 const struct lttng_kernel_event_field *field,
3171 size_t nesting)
3172 {
3173 int ret;
3174
3175 ret = _lttng_struct_type_statedump(session,
3176 lttng_kernel_get_type_struct(field->type), nesting);
3177 if (ret)
3178 return ret;
3179 return lttng_field_name_statedump(session, field, nesting);
3180 }
3181
3182 /*
3183 * Must be called with sessions_mutex held.
3184 */
3185 static
3186 int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
3187 const struct lttng_kernel_type_variant *type,
3188 size_t nesting,
3189 const char *prev_field_name)
3190 {
3191 const char *tag_name;
3192 int ret;
3193 uint32_t i, nr_choices;
3194
3195 tag_name = type->tag_name;
3196 if (!tag_name)
3197 tag_name = prev_field_name;
3198 if (!tag_name)
3199 return -EINVAL;
3200 /*
3201 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3202 */
3203 if (type->alignment != 0)
3204 return -EINVAL;
3205 ret = print_tabs(session, nesting);
3206 if (ret)
3207 return ret;
3208 ret = lttng_metadata_printf(session,
3209 "variant <_%s> {\n",
3210 tag_name);
3211 if (ret)
3212 return ret;
3213 nr_choices = type->nr_choices;
3214 for (i = 0; i < nr_choices; i++) {
3215 const struct lttng_kernel_event_field *iter_field;
3216
3217 iter_field = type->choices[i];
3218 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3219 if (ret)
3220 return ret;
3221 }
3222 ret = print_tabs(session, nesting);
3223 if (ret)
3224 return ret;
3225 ret = lttng_metadata_printf(session,
3226 "}");
3227 return ret;
3228 }
3229
3230 /*
3231 * Must be called with sessions_mutex held.
3232 */
3233 static
3234 int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3235 const struct lttng_kernel_event_field *field,
3236 size_t nesting,
3237 const char *prev_field_name)
3238 {
3239 int ret;
3240
3241 ret = _lttng_variant_type_statedump(session,
3242 lttng_kernel_get_type_variant(field->type), nesting,
3243 prev_field_name);
3244 if (ret)
3245 return ret;
3246 return lttng_field_name_statedump(session, field, nesting);
3247 }
3248
3249 /*
3250 * Must be called with sessions_mutex held.
3251 */
3252 static
3253 int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3254 const struct lttng_kernel_event_field *field,
3255 size_t nesting)
3256 {
3257 int ret;
3258 const struct lttng_kernel_type_array *array_type;
3259 const struct lttng_kernel_type_common *elem_type;
3260
3261 array_type = lttng_kernel_get_type_array(field->type);
3262 WARN_ON_ONCE(!array_type);
3263
3264 if (array_type->alignment) {
3265 ret = print_tabs(session, nesting);
3266 if (ret)
3267 return ret;
3268 ret = lttng_metadata_printf(session,
3269 "struct { } align(%u) _%s_padding;\n",
3270 array_type->alignment * CHAR_BIT,
3271 field->name);
3272 if (ret)
3273 return ret;
3274 }
3275 /*
3276 * Nested compound types: Only array of structures and variants are
3277 * currently supported.
3278 */
3279 elem_type = array_type->elem_type;
3280 switch (elem_type->type) {
3281 case lttng_kernel_type_integer:
3282 case lttng_kernel_type_struct:
3283 case lttng_kernel_type_variant:
3284 ret = _lttng_type_statedump(session, elem_type,
3285 array_type->encoding, nesting);
3286 if (ret)
3287 return ret;
3288 break;
3289
3290 default:
3291 return -EINVAL;
3292 }
3293 ret = lttng_metadata_printf(session,
3294 " _%s[%u];\n",
3295 field->name,
3296 array_type->length);
3297 return ret;
3298 }
3299
3300 /*
3301 * Must be called with sessions_mutex held.
3302 */
3303 static
3304 int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3305 const struct lttng_kernel_event_field *field,
3306 size_t nesting,
3307 const char *prev_field_name)
3308 {
3309 int ret;
3310 const char *length_name;
3311 const struct lttng_kernel_type_sequence *sequence_type;
3312 const struct lttng_kernel_type_common *elem_type;
3313
3314 sequence_type = lttng_kernel_get_type_sequence(field->type);
3315 WARN_ON_ONCE(!sequence_type);
3316
3317 length_name = sequence_type->length_name;
3318 if (!length_name)
3319 length_name = prev_field_name;
3320 if (!length_name)
3321 return -EINVAL;
3322
3323 if (sequence_type->alignment) {
3324 ret = print_tabs(session, nesting);
3325 if (ret)
3326 return ret;
3327 ret = lttng_metadata_printf(session,
3328 "struct { } align(%u) _%s_padding;\n",
3329 sequence_type->alignment * CHAR_BIT,
3330 field->name);
3331 if (ret)
3332 return ret;
3333 }
3334
3335 /*
3336 * Nested compound types: Only array of structures and variants are
3337 * currently supported.
3338 */
3339 elem_type = sequence_type->elem_type;
3340 switch (elem_type->type) {
3341 case lttng_kernel_type_integer:
3342 case lttng_kernel_type_struct:
3343 case lttng_kernel_type_variant:
3344 ret = _lttng_type_statedump(session, elem_type,
3345 sequence_type->encoding, nesting);
3346 if (ret)
3347 return ret;
3348 break;
3349
3350 default:
3351 return -EINVAL;
3352 }
3353 ret = lttng_metadata_printf(session,
3354 " _%s[ _%s ];\n",
3355 field->name,
3356 length_name);
3357 return ret;
3358 }
3359
3360 /*
3361 * Must be called with sessions_mutex held.
3362 */
3363 static
3364 int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3365 const struct lttng_kernel_type_enum *type,
3366 size_t nesting)
3367 {
3368 const struct lttng_kernel_enum_desc *enum_desc;
3369 const struct lttng_kernel_type_common *container_type;
3370 int ret;
3371 unsigned int i, nr_entries;
3372
3373 container_type = type->container_type;
3374 if (container_type->type != lttng_kernel_type_integer) {
3375 ret = -EINVAL;
3376 goto end;
3377 }
3378 enum_desc = type->desc;
3379 nr_entries = enum_desc->nr_entries;
3380
3381 ret = print_tabs(session, nesting);
3382 if (ret)
3383 goto end;
3384 ret = lttng_metadata_printf(session, "enum : ");
3385 if (ret)
3386 goto end;
3387 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3388 lttng_kernel_string_encoding_none, 0);
3389 if (ret)
3390 goto end;
3391 ret = lttng_metadata_printf(session, " {\n");
3392 if (ret)
3393 goto end;
3394 /* Dump all entries */
3395 for (i = 0; i < nr_entries; i++) {
3396 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3397 int j, len;
3398
3399 ret = print_tabs(session, nesting + 1);
3400 if (ret)
3401 goto end;
3402 ret = lttng_metadata_printf(session,
3403 "\"");
3404 if (ret)
3405 goto end;
3406 len = strlen(entry->string);
3407 /* Escape the character '"' */
3408 for (j = 0; j < len; j++) {
3409 char c = entry->string[j];
3410
3411 switch (c) {
3412 case '"':
3413 ret = lttng_metadata_printf(session,
3414 "\\\"");
3415 break;
3416 case '\\':
3417 ret = lttng_metadata_printf(session,
3418 "\\\\");
3419 break;
3420 default:
3421 ret = lttng_metadata_printf(session,
3422 "%c", c);
3423 break;
3424 }
3425 if (ret)
3426 goto end;
3427 }
3428 ret = lttng_metadata_printf(session, "\"");
3429 if (ret)
3430 goto end;
3431
3432 if (entry->options.is_auto) {
3433 ret = lttng_metadata_printf(session, ",\n");
3434 if (ret)
3435 goto end;
3436 } else {
3437 ret = lttng_metadata_printf(session,
3438 " = ");
3439 if (ret)
3440 goto end;
3441 if (entry->start.signedness)
3442 ret = lttng_metadata_printf(session,
3443 "%lld", (long long) entry->start.value);
3444 else
3445 ret = lttng_metadata_printf(session,
3446 "%llu", entry->start.value);
3447 if (ret)
3448 goto end;
3449 if (entry->start.signedness == entry->end.signedness &&
3450 entry->start.value
3451 == entry->end.value) {
3452 ret = lttng_metadata_printf(session,
3453 ",\n");
3454 } else {
3455 if (entry->end.signedness) {
3456 ret = lttng_metadata_printf(session,
3457 " ... %lld,\n",
3458 (long long) entry->end.value);
3459 } else {
3460 ret = lttng_metadata_printf(session,
3461 " ... %llu,\n",
3462 entry->end.value);
3463 }
3464 }
3465 if (ret)
3466 goto end;
3467 }
3468 }
3469 ret = print_tabs(session, nesting);
3470 if (ret)
3471 goto end;
3472 ret = lttng_metadata_printf(session, "}");
3473 end:
3474 return ret;
3475 }
3476
3477 /*
3478 * Must be called with sessions_mutex held.
3479 */
3480 static
3481 int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3482 const struct lttng_kernel_event_field *field,
3483 size_t nesting)
3484 {
3485 int ret;
3486 const struct lttng_kernel_type_enum *enum_type;
3487
3488 enum_type = lttng_kernel_get_type_enum(field->type);
3489 WARN_ON_ONCE(!enum_type);
3490 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3491 if (ret)
3492 return ret;
3493 return lttng_field_name_statedump(session, field, nesting);
3494 }
3495
3496 static
3497 int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3498 const struct lttng_kernel_event_field *field,
3499 size_t nesting)
3500 {
3501 int ret;
3502
3503 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3504 lttng_kernel_string_encoding_none, nesting);
3505 if (ret)
3506 return ret;
3507 return lttng_field_name_statedump(session, field, nesting);
3508 }
3509
3510 static
3511 int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3512 const struct lttng_kernel_type_string *type,
3513 size_t nesting)
3514 {
3515 int ret;
3516
3517 /* Default encoding is UTF8 */
3518 ret = print_tabs(session, nesting);
3519 if (ret)
3520 return ret;
3521 ret = lttng_metadata_printf(session,
3522 "string%s",
3523 type->encoding == lttng_kernel_string_encoding_ASCII ?
3524 " { encoding = ASCII; }" : "");
3525 return ret;
3526 }
3527
3528 static
3529 int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3530 const struct lttng_kernel_event_field *field,
3531 size_t nesting)
3532 {
3533 const struct lttng_kernel_type_string *string_type;
3534 int ret;
3535
3536 string_type = lttng_kernel_get_type_string(field->type);
3537 WARN_ON_ONCE(!string_type);
3538 ret = _lttng_string_type_statedump(session, string_type, nesting);
3539 if (ret)
3540 return ret;
3541 return lttng_field_name_statedump(session, field, nesting);
3542 }
3543
3544 /*
3545 * Must be called with sessions_mutex held.
3546 */
3547 static
3548 int _lttng_type_statedump(struct lttng_kernel_session *session,
3549 const struct lttng_kernel_type_common *type,
3550 enum lttng_kernel_string_encoding parent_encoding,
3551 size_t nesting)
3552 {
3553 int ret = 0;
3554
3555 switch (type->type) {
3556 case lttng_kernel_type_integer:
3557 ret = _lttng_integer_type_statedump(session,
3558 lttng_kernel_get_type_integer(type),
3559 parent_encoding, nesting);
3560 break;
3561 case lttng_kernel_type_enum:
3562 ret = _lttng_enum_type_statedump(session,
3563 lttng_kernel_get_type_enum(type),
3564 nesting);
3565 break;
3566 case lttng_kernel_type_string:
3567 ret = _lttng_string_type_statedump(session,
3568 lttng_kernel_get_type_string(type),
3569 nesting);
3570 break;
3571 case lttng_kernel_type_struct:
3572 ret = _lttng_struct_type_statedump(session,
3573 lttng_kernel_get_type_struct(type),
3574 nesting);
3575 break;
3576 case lttng_kernel_type_variant:
3577 ret = _lttng_variant_type_statedump(session,
3578 lttng_kernel_get_type_variant(type),
3579 nesting, NULL);
3580 break;
3581
3582 /* Nested arrays and sequences are not supported yet. */
3583 case lttng_kernel_type_array:
3584 case lttng_kernel_type_sequence:
3585 default:
3586 WARN_ON_ONCE(1);
3587 return -EINVAL;
3588 }
3589 return ret;
3590 }
3591
3592 /*
3593 * Must be called with sessions_mutex held.
3594 */
3595 static
3596 int _lttng_field_statedump(struct lttng_kernel_session *session,
3597 const struct lttng_kernel_event_field *field,
3598 size_t nesting,
3599 const char **prev_field_name_p)
3600 {
3601 const char *prev_field_name = NULL;
3602 int ret = 0;
3603
3604 if (prev_field_name_p)
3605 prev_field_name = *prev_field_name_p;
3606 switch (field->type->type) {
3607 case lttng_kernel_type_integer:
3608 ret = _lttng_integer_field_statedump(session, field, nesting);
3609 break;
3610 case lttng_kernel_type_enum:
3611 ret = _lttng_enum_field_statedump(session, field, nesting);
3612 break;
3613 case lttng_kernel_type_string:
3614 ret = _lttng_string_field_statedump(session, field, nesting);
3615 break;
3616 case lttng_kernel_type_struct:
3617 ret = _lttng_struct_field_statedump(session, field, nesting);
3618 break;
3619 case lttng_kernel_type_array:
3620 ret = _lttng_array_field_statedump(session, field, nesting);
3621 break;
3622 case lttng_kernel_type_sequence:
3623 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3624 break;
3625 case lttng_kernel_type_variant:
3626 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3627 break;
3628
3629 default:
3630 WARN_ON_ONCE(1);
3631 return -EINVAL;
3632 }
3633 if (prev_field_name_p)
3634 *prev_field_name_p = field->name;
3635 return ret;
3636 }
3637
3638 static
3639 int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3640 struct lttng_kernel_ctx *ctx)
3641 {
3642 const char *prev_field_name = NULL;
3643 int ret = 0;
3644 int i;
3645
3646 if (!ctx)
3647 return 0;
3648 for (i = 0; i < ctx->nr_fields; i++) {
3649 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3650
3651 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3652 if (ret)
3653 return ret;
3654 }
3655 return ret;
3656 }
3657
3658 static
3659 int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3660 struct lttng_kernel_event_recorder *event_recorder)
3661 {
3662 const char *prev_field_name = NULL;
3663 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3664 int ret = 0;
3665 int i;
3666
3667 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3668 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3669
3670 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3671 if (ret)
3672 return ret;
3673 }
3674 return ret;
3675 }
3676
3677 /*
3678 * Must be called with sessions_mutex held.
3679 * The entire event metadata is printed as a single atomic metadata
3680 * transaction.
3681 */
3682 static
3683 int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
3684 struct lttng_kernel_channel_buffer *chan,
3685 struct lttng_kernel_event_recorder *event_recorder)
3686 {
3687 int ret = 0;
3688
3689 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3690 return 0;
3691 if (chan->priv->channel_type == METADATA_CHANNEL)
3692 return 0;
3693
3694 lttng_metadata_begin(session);
3695
3696 ret = lttng_metadata_printf(session,
3697 "event {\n"
3698 " name = \"%s\";\n"
3699 " id = %u;\n"
3700 " stream_id = %u;\n",
3701 event_recorder->priv->parent.desc->event_name,
3702 event_recorder->priv->id,
3703 event_recorder->chan->priv->id);
3704 if (ret)
3705 goto end;
3706
3707 ret = lttng_metadata_printf(session,
3708 " fields := struct {\n"
3709 );
3710 if (ret)
3711 goto end;
3712
3713 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3714 if (ret)
3715 goto end;
3716
3717 /*
3718 * LTTng space reservation can only reserve multiples of the
3719 * byte size.
3720 */
3721 ret = lttng_metadata_printf(session,
3722 " };\n"
3723 "};\n\n");
3724 if (ret)
3725 goto end;
3726
3727 event_recorder->priv->metadata_dumped = 1;
3728 end:
3729 lttng_metadata_end(session);
3730 return ret;
3731
3732 }
3733
3734 /*
3735 * Must be called with sessions_mutex held.
3736 * The entire channel metadata is printed as a single atomic metadata
3737 * transaction.
3738 */
3739 static
3740 int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3741 struct lttng_kernel_channel_buffer *chan)
3742 {
3743 int ret = 0;
3744
3745 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3746 return 0;
3747
3748 if (chan->priv->channel_type == METADATA_CHANNEL)
3749 return 0;
3750
3751 lttng_metadata_begin(session);
3752
3753 WARN_ON_ONCE(!chan->priv->header_type);
3754 ret = lttng_metadata_printf(session,
3755 "stream {\n"
3756 " id = %u;\n"
3757 " event.header := %s;\n"
3758 " packet.context := struct packet_context;\n",
3759 chan->priv->id,
3760 chan->priv->header_type == 1 ? "struct event_header_compact" :
3761 "struct event_header_large");
3762 if (ret)
3763 goto end;
3764
3765 if (chan->priv->ctx) {
3766 ret = lttng_metadata_printf(session,
3767 " event.context := struct {\n");
3768 if (ret)
3769 goto end;
3770 }
3771 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3772 if (ret)
3773 goto end;
3774 if (chan->priv->ctx) {
3775 ret = lttng_metadata_printf(session,
3776 " };\n");
3777 if (ret)
3778 goto end;
3779 }
3780
3781 ret = lttng_metadata_printf(session,
3782 "};\n\n");
3783
3784 chan->priv->metadata_dumped = 1;
3785 end:
3786 lttng_metadata_end(session);
3787 return ret;
3788 }
3789
3790 /*
3791 * Must be called with sessions_mutex held.
3792 */
3793 static
3794 int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3795 {
3796 return lttng_metadata_printf(session,
3797 "struct packet_context {\n"
3798 " uint64_clock_monotonic_t timestamp_begin;\n"
3799 " uint64_clock_monotonic_t timestamp_end;\n"
3800 " uint64_t content_size;\n"
3801 " uint64_t packet_size;\n"
3802 " uint64_t packet_seq_num;\n"
3803 " unsigned long events_discarded;\n"
3804 " uint32_t cpu_id;\n"
3805 "};\n\n"
3806 );
3807 }
3808
3809 /*
3810 * Compact header:
3811 * id: range: 0 - 30.
3812 * id 31 is reserved to indicate an extended header.
3813 *
3814 * Large header:
3815 * id: range: 0 - 65534.
3816 * id 65535 is reserved to indicate an extended header.
3817 *
3818 * Must be called with sessions_mutex held.
3819 */
3820 static
3821 int _lttng_event_header_declare(struct lttng_kernel_session *session)
3822 {
3823 return lttng_metadata_printf(session,
3824 "struct event_header_compact {\n"
3825 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3826 " variant <id> {\n"
3827 " struct {\n"
3828 " uint27_clock_monotonic_t timestamp;\n"
3829 " } compact;\n"
3830 " struct {\n"
3831 " uint32_t id;\n"
3832 " uint64_clock_monotonic_t timestamp;\n"
3833 " } extended;\n"
3834 " } v;\n"
3835 "} align(%u);\n"
3836 "\n"
3837 "struct event_header_large {\n"
3838 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3839 " variant <id> {\n"
3840 " struct {\n"
3841 " uint32_clock_monotonic_t timestamp;\n"
3842 " } compact;\n"
3843 " struct {\n"
3844 " uint32_t id;\n"
3845 " uint64_clock_monotonic_t timestamp;\n"
3846 " } extended;\n"
3847 " } v;\n"
3848 "} align(%u);\n\n",
3849 lttng_alignof(uint32_t) * CHAR_BIT,
3850 lttng_alignof(uint16_t) * CHAR_BIT
3851 );
3852 }
3853
3854 /*
3855 * Approximation of NTP time of day to clock monotonic correlation,
3856 * taken at start of trace.
3857 * Yes, this is only an approximation. Yes, we can (and will) do better
3858 * in future versions.
3859 * This function may return a negative offset. It may happen if the
3860 * system sets the REALTIME clock to 0 after boot.
3861 *
3862 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3863 * y2038 compliant.
3864 */
3865 static
3866 int64_t measure_clock_offset(void)
3867 {
3868 uint64_t monotonic_avg, monotonic[2], realtime;
3869 uint64_t tcf = trace_clock_freq();
3870 int64_t offset;
3871 unsigned long flags;
3872 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3873 struct timespec64 rts = { 0, 0 };
3874 #else
3875 struct timespec rts = { 0, 0 };
3876 #endif
3877
3878 /* Disable interrupts to increase correlation precision. */
3879 local_irq_save(flags);
3880 monotonic[0] = trace_clock_read64();
3881 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3882 ktime_get_real_ts64(&rts);
3883 #else
3884 getnstimeofday(&rts);
3885 #endif
3886 monotonic[1] = trace_clock_read64();
3887 local_irq_restore(flags);
3888
3889 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3890 realtime = (uint64_t) rts.tv_sec * tcf;
3891 if (tcf == NSEC_PER_SEC) {
3892 realtime += rts.tv_nsec;
3893 } else {
3894 uint64_t n = rts.tv_nsec * tcf;
3895
3896 do_div(n, NSEC_PER_SEC);
3897 realtime += n;
3898 }
3899 offset = (int64_t) realtime - monotonic_avg;
3900 return offset;
3901 }
3902
3903 static
3904 int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3905 {
3906 int ret = 0;
3907 size_t i;
3908 char cur;
3909
3910 i = 0;
3911 cur = string[i];
3912 while (cur != '\0') {
3913 switch (cur) {
3914 case '\n':
3915 ret = lttng_metadata_printf(session, "%s", "\\n");
3916 break;
3917 case '\\':
3918 case '"':
3919 ret = lttng_metadata_printf(session, "%c", '\\');
3920 if (ret)
3921 goto error;
3922 /* We still print the current char */
3923 lttng_fallthrough;
3924 default:
3925 ret = lttng_metadata_printf(session, "%c", cur);
3926 break;
3927 }
3928
3929 if (ret)
3930 goto error;
3931
3932 cur = string[++i];
3933 }
3934 error:
3935 return ret;
3936 }
3937
3938 static
3939 int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3940 const char *field_value)
3941 {
3942 int ret;
3943
3944 ret = lttng_metadata_printf(session, " %s = \"", field);
3945 if (ret)
3946 goto error;
3947
3948 ret = print_escaped_ctf_string(session, field_value);
3949 if (ret)
3950 goto error;
3951
3952 ret = lttng_metadata_printf(session, "\";\n");
3953
3954 error:
3955 return ret;
3956 }
3957
3958 /*
3959 * Output metadata into this session's metadata buffers.
3960 * Must be called with sessions_mutex held.
3961 */
3962 static
3963 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3964 {
3965 unsigned char *uuid_c = session->priv->uuid.b;
3966 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3967 const char *product_uuid;
3968 struct lttng_kernel_channel_buffer_private *chan_priv;
3969 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3970 int ret = 0;
3971
3972 if (!LTTNG_READ_ONCE(session->active))
3973 return 0;
3974
3975 lttng_metadata_begin(session);
3976
3977 if (session->priv->metadata_dumped)
3978 goto skip_session;
3979
3980 snprintf(uuid_s, sizeof(uuid_s),
3981 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3982 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3983 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3984 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3985 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3986
3987 ret = lttng_metadata_printf(session,
3988 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3989 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3990 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3991 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3992 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3993 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3994 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3995 "\n"
3996 "trace {\n"
3997 " major = %u;\n"
3998 " minor = %u;\n"
3999 " uuid = \"%s\";\n"
4000 " byte_order = %s;\n"
4001 " packet.header := struct {\n"
4002 " uint32_t magic;\n"
4003 " uint8_t uuid[16];\n"
4004 " uint32_t stream_id;\n"
4005 " uint64_t stream_instance_id;\n"
4006 " };\n"
4007 "};\n\n",
4008 lttng_alignof(uint8_t) * CHAR_BIT,
4009 lttng_alignof(uint16_t) * CHAR_BIT,
4010 lttng_alignof(uint32_t) * CHAR_BIT,
4011 lttng_alignof(uint64_t) * CHAR_BIT,
4012 sizeof(unsigned long) * CHAR_BIT,
4013 lttng_alignof(unsigned long) * CHAR_BIT,
4014 CTF_SPEC_MAJOR,
4015 CTF_SPEC_MINOR,
4016 uuid_s,
4017 #if __BYTE_ORDER == __BIG_ENDIAN
4018 "be"
4019 #else
4020 "le"
4021 #endif
4022 );
4023 if (ret)
4024 goto end;
4025
4026 ret = lttng_metadata_printf(session,
4027 "env {\n"
4028 " hostname = \"%s\";\n"
4029 " domain = \"kernel\";\n"
4030 " sysname = \"%s\";\n"
4031 " kernel_release = \"%s\";\n"
4032 " kernel_version = \"%s\";\n"
4033 " tracer_name = \"lttng-modules\";\n"
4034 " tracer_major = %d;\n"
4035 " tracer_minor = %d;\n"
4036 " tracer_patchlevel = %d;\n"
4037 " trace_buffering_scheme = \"global\";\n",
4038 current->nsproxy->uts_ns->name.nodename,
4039 utsname()->sysname,
4040 utsname()->release,
4041 utsname()->version,
4042 LTTNG_MODULES_MAJOR_VERSION,
4043 LTTNG_MODULES_MINOR_VERSION,
4044 LTTNG_MODULES_PATCHLEVEL_VERSION
4045 );
4046 if (ret)
4047 goto end;
4048
4049 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
4050 if (ret)
4051 goto end;
4052 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
4053 session->priv->creation_time);
4054 if (ret)
4055 goto end;
4056
4057 /* Add the product UUID to the 'env' section */
4058 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
4059 if (product_uuid) {
4060 ret = lttng_metadata_printf(session,
4061 " product_uuid = \"%s\";\n",
4062 product_uuid
4063 );
4064 if (ret)
4065 goto end;
4066 }
4067
4068 /* Close the 'env' section */
4069 ret = lttng_metadata_printf(session, "};\n\n");
4070 if (ret)
4071 goto end;
4072
4073 ret = lttng_metadata_printf(session,
4074 "clock {\n"
4075 " name = \"%s\";\n",
4076 trace_clock_name()
4077 );
4078 if (ret)
4079 goto end;
4080
4081 if (!trace_clock_uuid(clock_uuid_s)) {
4082 ret = lttng_metadata_printf(session,
4083 " uuid = \"%s\";\n",
4084 clock_uuid_s
4085 );
4086 if (ret)
4087 goto end;
4088 }
4089
4090 ret = lttng_metadata_printf(session,
4091 " description = \"%s\";\n"
4092 " freq = %llu; /* Frequency, in Hz */\n"
4093 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
4094 " offset = %lld;\n"
4095 "};\n\n",
4096 trace_clock_description(),
4097 (unsigned long long) trace_clock_freq(),
4098 (long long) measure_clock_offset()
4099 );
4100 if (ret)
4101 goto end;
4102
4103 ret = lttng_metadata_printf(session,
4104 "typealias integer {\n"
4105 " size = 27; align = 1; signed = false;\n"
4106 " map = clock.%s.value;\n"
4107 "} := uint27_clock_monotonic_t;\n"
4108 "\n"
4109 "typealias integer {\n"
4110 " size = 32; align = %u; signed = false;\n"
4111 " map = clock.%s.value;\n"
4112 "} := uint32_clock_monotonic_t;\n"
4113 "\n"
4114 "typealias integer {\n"
4115 " size = 64; align = %u; signed = false;\n"
4116 " map = clock.%s.value;\n"
4117 "} := uint64_clock_monotonic_t;\n\n",
4118 trace_clock_name(),
4119 lttng_alignof(uint32_t) * CHAR_BIT,
4120 trace_clock_name(),
4121 lttng_alignof(uint64_t) * CHAR_BIT,
4122 trace_clock_name()
4123 );
4124 if (ret)
4125 goto end;
4126
4127 ret = _lttng_stream_packet_context_declare(session);
4128 if (ret)
4129 goto end;
4130
4131 ret = _lttng_event_header_declare(session);
4132 if (ret)
4133 goto end;
4134
4135 skip_session:
4136 list_for_each_entry(chan_priv, &session->priv->chan, node) {
4137 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
4138 if (ret)
4139 goto end;
4140 }
4141
4142 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
4143 ret = _lttng_event_metadata_statedump(session, event_recorder_priv->pub->chan,
4144 event_recorder_priv->pub);
4145 if (ret)
4146 goto end;
4147 }
4148 session->priv->metadata_dumped = 1;
4149 end:
4150 lttng_metadata_end(session);
4151 return ret;
4152 }
4153
4154 /**
4155 * lttng_transport_register - LTT transport registration
4156 * @transport: transport structure
4157 *
4158 * Registers a transport which can be used as output to extract the data out of
4159 * LTTng. The module calling this registration function must ensure that no
4160 * trap-inducing code will be executed by the transport functions. E.g.
4161 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
4162 * is made visible to the transport function. This registration acts as a
4163 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
4164 * after its registration must it synchronize the TLBs.
4165 */
4166 void lttng_transport_register(struct lttng_transport *transport)
4167 {
4168 /*
4169 * Make sure no page fault can be triggered by the module about to be
4170 * registered. We deal with this here so we don't have to call
4171 * vmalloc_sync_mappings() in each module's init.
4172 */
4173 wrapper_vmalloc_sync_mappings();
4174
4175 mutex_lock(&sessions_mutex);
4176 list_add_tail(&transport->node, &lttng_transport_list);
4177 mutex_unlock(&sessions_mutex);
4178 }
4179 EXPORT_SYMBOL_GPL(lttng_transport_register);
4180
4181 /**
4182 * lttng_transport_unregister - LTT transport unregistration
4183 * @transport: transport structure
4184 */
4185 void lttng_transport_unregister(struct lttng_transport *transport)
4186 {
4187 mutex_lock(&sessions_mutex);
4188 list_del(&transport->node);
4189 mutex_unlock(&sessions_mutex);
4190 }
4191 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4192
4193 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4194 {
4195 /*
4196 * Make sure no page fault can be triggered by the module about to be
4197 * registered. We deal with this here so we don't have to call
4198 * vmalloc_sync_mappings() in each module's init.
4199 */
4200 wrapper_vmalloc_sync_mappings();
4201
4202 mutex_lock(&sessions_mutex);
4203 list_add_tail(&transport->node, &lttng_counter_transport_list);
4204 mutex_unlock(&sessions_mutex);
4205 }
4206 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4207
4208 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4209 {
4210 mutex_lock(&sessions_mutex);
4211 list_del(&transport->node);
4212 mutex_unlock(&sessions_mutex);
4213 }
4214 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4215
4216 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4217
4218 enum cpuhp_state lttng_hp_prepare;
4219 enum cpuhp_state lttng_hp_online;
4220
4221 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4222 {
4223 struct lttng_cpuhp_node *lttng_node;
4224
4225 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4226 switch (lttng_node->component) {
4227 case LTTNG_RING_BUFFER_FRONTEND:
4228 return 0;
4229 case LTTNG_RING_BUFFER_BACKEND:
4230 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4231 case LTTNG_RING_BUFFER_ITER:
4232 return 0;
4233 case LTTNG_CONTEXT_PERF_COUNTERS:
4234 return 0;
4235 default:
4236 return -EINVAL;
4237 }
4238 }
4239
4240 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4241 {
4242 struct lttng_cpuhp_node *lttng_node;
4243
4244 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4245 switch (lttng_node->component) {
4246 case LTTNG_RING_BUFFER_FRONTEND:
4247 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4248 case LTTNG_RING_BUFFER_BACKEND:
4249 return 0;
4250 case LTTNG_RING_BUFFER_ITER:
4251 return 0;
4252 case LTTNG_CONTEXT_PERF_COUNTERS:
4253 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4254 default:
4255 return -EINVAL;
4256 }
4257 }
4258
4259 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4260 {
4261 struct lttng_cpuhp_node *lttng_node;
4262
4263 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4264 switch (lttng_node->component) {
4265 case LTTNG_RING_BUFFER_FRONTEND:
4266 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4267 case LTTNG_RING_BUFFER_BACKEND:
4268 return 0;
4269 case LTTNG_RING_BUFFER_ITER:
4270 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4271 case LTTNG_CONTEXT_PERF_COUNTERS:
4272 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4273 default:
4274 return -EINVAL;
4275 }
4276 }
4277
4278 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4279 {
4280 struct lttng_cpuhp_node *lttng_node;
4281
4282 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4283 switch (lttng_node->component) {
4284 case LTTNG_RING_BUFFER_FRONTEND:
4285 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4286 case LTTNG_RING_BUFFER_BACKEND:
4287 return 0;
4288 case LTTNG_RING_BUFFER_ITER:
4289 return 0;
4290 case LTTNG_CONTEXT_PERF_COUNTERS:
4291 return 0;
4292 default:
4293 return -EINVAL;
4294 }
4295 }
4296
4297 static int __init lttng_init_cpu_hotplug(void)
4298 {
4299 int ret;
4300
4301 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4302 lttng_hotplug_prepare,
4303 lttng_hotplug_dead);
4304 if (ret < 0) {
4305 return ret;
4306 }
4307 lttng_hp_prepare = ret;
4308 lttng_rb_set_hp_prepare(ret);
4309
4310 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4311 lttng_hotplug_online,
4312 lttng_hotplug_offline);
4313 if (ret < 0) {
4314 cpuhp_remove_multi_state(lttng_hp_prepare);
4315 lttng_hp_prepare = 0;
4316 return ret;
4317 }
4318 lttng_hp_online = ret;
4319 lttng_rb_set_hp_online(ret);
4320
4321 return 0;
4322 }
4323
4324 static void __exit lttng_exit_cpu_hotplug(void)
4325 {
4326 lttng_rb_set_hp_online(0);
4327 cpuhp_remove_multi_state(lttng_hp_online);
4328 lttng_rb_set_hp_prepare(0);
4329 cpuhp_remove_multi_state(lttng_hp_prepare);
4330 }
4331
4332 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4333 static int lttng_init_cpu_hotplug(void)
4334 {
4335 return 0;
4336 }
4337 static void lttng_exit_cpu_hotplug(void)
4338 {
4339 }
4340 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4341
4342 static int __init lttng_events_init(void)
4343 {
4344 int ret;
4345
4346 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4347 if (ret)
4348 return ret;
4349 ret = wrapper_get_pfnblock_flags_mask_init();
4350 if (ret)
4351 return ret;
4352 ret = wrapper_get_pageblock_flags_mask_init();
4353 if (ret)
4354 return ret;
4355 ret = lttng_probes_init();
4356 if (ret)
4357 return ret;
4358 ret = lttng_context_init();
4359 if (ret)
4360 return ret;
4361 ret = lttng_tracepoint_init();
4362 if (ret)
4363 goto error_tp;
4364 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4365 if (!event_recorder_cache) {
4366 ret = -ENOMEM;
4367 goto error_kmem_event_recorder;
4368 }
4369 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4370 if (!event_recorder_private_cache) {
4371 ret = -ENOMEM;
4372 goto error_kmem_event_recorder_private;
4373 }
4374 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4375 if (!event_notifier_cache) {
4376 ret = -ENOMEM;
4377 goto error_kmem_event_notifier;
4378 }
4379 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4380 if (!event_notifier_private_cache) {
4381 ret = -ENOMEM;
4382 goto error_kmem_event_notifier_private;
4383 }
4384 ret = lttng_abi_init();
4385 if (ret)
4386 goto error_abi;
4387 ret = lttng_logger_init();
4388 if (ret)
4389 goto error_logger;
4390 ret = lttng_init_cpu_hotplug();
4391 if (ret)
4392 goto error_hotplug;
4393 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4394 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4395 __stringify(LTTNG_MODULES_MINOR_VERSION),
4396 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4397 LTTNG_MODULES_EXTRAVERSION,
4398 LTTNG_VERSION_NAME,
4399 #ifdef LTTNG_EXTRA_VERSION_GIT
4400 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4401 #else
4402 "",
4403 #endif
4404 #ifdef LTTNG_EXTRA_VERSION_NAME
4405 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4406 #else
4407 "");
4408 #endif
4409 #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
4410 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
4411 #endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
4412 return 0;
4413
4414 error_hotplug:
4415 lttng_logger_exit();
4416 error_logger:
4417 lttng_abi_exit();
4418 error_abi:
4419 kmem_cache_destroy(event_notifier_private_cache);
4420 error_kmem_event_notifier_private:
4421 kmem_cache_destroy(event_notifier_cache);
4422 error_kmem_event_notifier:
4423 kmem_cache_destroy(event_recorder_private_cache);
4424 error_kmem_event_recorder_private:
4425 kmem_cache_destroy(event_recorder_cache);
4426 error_kmem_event_recorder:
4427 lttng_tracepoint_exit();
4428 error_tp:
4429 lttng_context_exit();
4430 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4431 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4432 __stringify(LTTNG_MODULES_MINOR_VERSION),
4433 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4434 LTTNG_MODULES_EXTRAVERSION,
4435 LTTNG_VERSION_NAME,
4436 #ifdef LTTNG_EXTRA_VERSION_GIT
4437 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4438 #else
4439 "",
4440 #endif
4441 #ifdef LTTNG_EXTRA_VERSION_NAME
4442 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4443 #else
4444 "");
4445 #endif
4446 return ret;
4447 }
4448
4449 module_init(lttng_events_init);
4450
4451 static void __exit lttng_events_exit(void)
4452 {
4453 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4454
4455 lttng_exit_cpu_hotplug();
4456 lttng_logger_exit();
4457 lttng_abi_exit();
4458 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4459 lttng_session_destroy(session_priv->pub);
4460 kmem_cache_destroy(event_recorder_cache);
4461 kmem_cache_destroy(event_recorder_private_cache);
4462 kmem_cache_destroy(event_notifier_cache);
4463 kmem_cache_destroy(event_notifier_private_cache);
4464 lttng_tracepoint_exit();
4465 lttng_context_exit();
4466 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4467 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4468 __stringify(LTTNG_MODULES_MINOR_VERSION),
4469 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4470 LTTNG_MODULES_EXTRAVERSION,
4471 LTTNG_VERSION_NAME,
4472 #ifdef LTTNG_EXTRA_VERSION_GIT
4473 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4474 #else
4475 "",
4476 #endif
4477 #ifdef LTTNG_EXTRA_VERSION_NAME
4478 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4479 #else
4480 "");
4481 #endif
4482 }
4483
4484 module_exit(lttng_events_exit);
4485
4486 #include <generated/patches.h>
4487 #ifdef LTTNG_EXTRA_VERSION_GIT
4488 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4489 #endif
4490 #ifdef LTTNG_EXTRA_VERSION_NAME
4491 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4492 #endif
4493 MODULE_LICENSE("GPL and additional rights");
4494 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4495 MODULE_DESCRIPTION("LTTng tracer");
4496 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4497 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4498 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4499 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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