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Warn on event registration/unregistration failure
[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 void _lttng_event_unregister(struct lttng_kernel_event_recorder *event);
76 static void _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 _lttng_event_unregister(event_recorder_priv->pub);
369 synchronize_trace(); /* Wait for in-flight events to complete */
370 list_for_each_entry(chan_priv, &session->priv->chan, node) {
371 ret = lttng_syscalls_destroy_event(chan_priv->pub);
372 WARN_ON(ret);
373 }
374 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
375 &session->priv->enablers_head, node)
376 lttng_event_enabler_destroy(event_enabler);
377 list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv, &session->priv->events, node)
378 _lttng_event_destroy(&event_recorder_priv->pub->parent);
379 list_for_each_entry_safe(chan_priv, tmpchan_priv, &session->priv->chan, node) {
380 BUG_ON(chan_priv->channel_type == METADATA_CHANNEL);
381 _lttng_channel_destroy(chan_priv->pub);
382 }
383 mutex_lock(&session->priv->metadata_cache->lock);
384 list_for_each_entry(metadata_stream, &session->priv->metadata_cache->metadata_stream, list)
385 _lttng_metadata_channel_hangup(metadata_stream);
386 mutex_unlock(&session->priv->metadata_cache->lock);
387 lttng_id_tracker_fini(&session->pid_tracker);
388 lttng_id_tracker_fini(&session->vpid_tracker);
389 lttng_id_tracker_fini(&session->uid_tracker);
390 lttng_id_tracker_fini(&session->vuid_tracker);
391 lttng_id_tracker_fini(&session->gid_tracker);
392 lttng_id_tracker_fini(&session->vgid_tracker);
393 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
394 list_del(&session->priv->list);
395 mutex_unlock(&sessions_mutex);
396 lttng_kvfree(session->priv);
397 lttng_kvfree(session);
398 }
399
400 void lttng_event_notifier_group_destroy(
401 struct lttng_event_notifier_group *event_notifier_group)
402 {
403 struct lttng_event_notifier_enabler *event_notifier_enabler, *tmp_event_notifier_enabler;
404 struct lttng_kernel_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
405 int ret;
406
407 if (!event_notifier_group)
408 return;
409
410 mutex_lock(&sessions_mutex);
411
412 ret = lttng_syscalls_unregister_event_notifier_group(event_notifier_group);
413 WARN_ON(ret);
414
415 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
416 &event_notifier_group->event_notifiers_head, node)
417 _lttng_event_notifier_unregister(event_notifier_priv->pub);
418
419 /* Wait for in-flight event notifier to complete */
420 synchronize_trace();
421
422 irq_work_sync(&event_notifier_group->wakeup_pending);
423
424 kfree(event_notifier_group->sc_filter);
425
426 list_for_each_entry_safe(event_notifier_enabler, tmp_event_notifier_enabler,
427 &event_notifier_group->enablers_head, node)
428 lttng_event_notifier_enabler_destroy(event_notifier_enabler);
429
430 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
431 &event_notifier_group->event_notifiers_head, node)
432 _lttng_event_destroy(&event_notifier_priv->pub->parent);
433
434 if (event_notifier_group->error_counter) {
435 struct lttng_counter *error_counter = event_notifier_group->error_counter;
436
437 error_counter->ops->counter_destroy(error_counter->counter);
438 module_put(error_counter->transport->owner);
439 lttng_kvfree(error_counter);
440 event_notifier_group->error_counter = NULL;
441 }
442
443 event_notifier_group->ops->priv->channel_destroy(event_notifier_group->chan);
444 module_put(event_notifier_group->transport->owner);
445 list_del(&event_notifier_group->node);
446
447 mutex_unlock(&sessions_mutex);
448 lttng_kvfree(event_notifier_group);
449 }
450
451 int lttng_session_statedump(struct lttng_kernel_session *session)
452 {
453 int ret;
454
455 mutex_lock(&sessions_mutex);
456 ret = lttng_statedump_start(session);
457 mutex_unlock(&sessions_mutex);
458 return ret;
459 }
460
461 int lttng_session_enable(struct lttng_kernel_session *session)
462 {
463 int ret = 0;
464 struct lttng_kernel_channel_buffer_private *chan_priv;
465
466 mutex_lock(&sessions_mutex);
467 if (session->active) {
468 ret = -EBUSY;
469 goto end;
470 }
471
472 /* Set transient enabler state to "enabled" */
473 session->priv->tstate = 1;
474
475 /* We need to sync enablers with session before activation. */
476 lttng_session_sync_event_enablers(session);
477
478 /*
479 * Snapshot the number of events per channel to know the type of header
480 * we need to use.
481 */
482 list_for_each_entry(chan_priv, &session->priv->chan, node) {
483 if (chan_priv->header_type)
484 continue; /* don't change it if session stop/restart */
485 if (chan_priv->free_event_id < 31)
486 chan_priv->header_type = 1; /* compact */
487 else
488 chan_priv->header_type = 2; /* large */
489 }
490
491 /* Clear each stream's quiescent state. */
492 list_for_each_entry(chan_priv, &session->priv->chan, node) {
493 if (chan_priv->channel_type != METADATA_CHANNEL)
494 lib_ring_buffer_clear_quiescent_channel(chan_priv->rb_chan);
495 }
496
497 WRITE_ONCE(session->active, 1);
498 WRITE_ONCE(session->priv->been_active, 1);
499 ret = _lttng_session_metadata_statedump(session);
500 if (ret) {
501 WRITE_ONCE(session->active, 0);
502 goto end;
503 }
504 ret = lttng_statedump_start(session);
505 if (ret)
506 WRITE_ONCE(session->active, 0);
507 end:
508 mutex_unlock(&sessions_mutex);
509 return ret;
510 }
511
512 int lttng_session_disable(struct lttng_kernel_session *session)
513 {
514 int ret = 0;
515 struct lttng_kernel_channel_buffer_private *chan_priv;
516
517 mutex_lock(&sessions_mutex);
518 if (!session->active) {
519 ret = -EBUSY;
520 goto end;
521 }
522 WRITE_ONCE(session->active, 0);
523
524 /* Set transient enabler state to "disabled" */
525 session->priv->tstate = 0;
526 lttng_session_sync_event_enablers(session);
527
528 /* Set each stream's quiescent state. */
529 list_for_each_entry(chan_priv, &session->priv->chan, node) {
530 if (chan_priv->channel_type != METADATA_CHANNEL)
531 lib_ring_buffer_set_quiescent_channel(chan_priv->rb_chan);
532 }
533 end:
534 mutex_unlock(&sessions_mutex);
535 return ret;
536 }
537
538 int lttng_session_metadata_regenerate(struct lttng_kernel_session *session)
539 {
540 int ret = 0;
541 struct lttng_kernel_channel_buffer_private *chan_priv;
542 struct lttng_kernel_event_recorder_private *event_recorder_priv;
543 struct lttng_metadata_cache *cache = session->priv->metadata_cache;
544 struct lttng_metadata_stream *stream;
545
546 mutex_lock(&sessions_mutex);
547 if (!session->active) {
548 ret = -EBUSY;
549 goto end;
550 }
551
552 mutex_lock(&cache->lock);
553 memset(cache->data, 0, cache->cache_alloc);
554 cache->metadata_written = 0;
555 cache->version++;
556 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list) {
557 stream->metadata_out = 0;
558 stream->metadata_in = 0;
559 }
560 mutex_unlock(&cache->lock);
561
562 session->priv->metadata_dumped = 0;
563 list_for_each_entry(chan_priv, &session->priv->chan, node) {
564 chan_priv->metadata_dumped = 0;
565 }
566
567 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
568 event_recorder_priv->metadata_dumped = 0;
569 }
570
571 ret = _lttng_session_metadata_statedump(session);
572
573 end:
574 mutex_unlock(&sessions_mutex);
575 return ret;
576 }
577
578 int lttng_channel_enable(struct lttng_kernel_channel_buffer *channel)
579 {
580 int ret = 0;
581
582 mutex_lock(&sessions_mutex);
583 if (channel->priv->channel_type == METADATA_CHANNEL) {
584 ret = -EPERM;
585 goto end;
586 }
587 if (channel->parent.enabled) {
588 ret = -EEXIST;
589 goto end;
590 }
591 /* Set transient enabler state to "enabled" */
592 channel->priv->parent.tstate = 1;
593 lttng_session_sync_event_enablers(channel->parent.session);
594 /* Set atomically the state to "enabled" */
595 WRITE_ONCE(channel->parent.enabled, 1);
596 end:
597 mutex_unlock(&sessions_mutex);
598 return ret;
599 }
600
601 int lttng_channel_disable(struct lttng_kernel_channel_buffer *channel)
602 {
603 int ret = 0;
604
605 mutex_lock(&sessions_mutex);
606 if (channel->priv->channel_type == METADATA_CHANNEL) {
607 ret = -EPERM;
608 goto end;
609 }
610 if (!channel->parent.enabled) {
611 ret = -EEXIST;
612 goto end;
613 }
614 /* Set atomically the state to "disabled" */
615 WRITE_ONCE(channel->parent.enabled, 0);
616 /* Set transient enabler state to "enabled" */
617 channel->priv->parent.tstate = 0;
618 lttng_session_sync_event_enablers(channel->parent.session);
619 end:
620 mutex_unlock(&sessions_mutex);
621 return ret;
622 }
623
624 int lttng_event_enable(struct lttng_kernel_event_common *event)
625 {
626 int ret = 0;
627
628 mutex_lock(&sessions_mutex);
629 switch (event->type) {
630 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
631 {
632 struct lttng_kernel_event_recorder *event_recorder =
633 container_of(event, struct lttng_kernel_event_recorder, parent);
634
635 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
636 ret = -EPERM;
637 goto end;
638 }
639 break;
640 }
641 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
642 switch (event->priv->instrumentation) {
643 case LTTNG_KERNEL_ABI_KRETPROBE:
644 ret = -EINVAL;
645 goto end;
646 default:
647 break;
648 }
649 break;
650 default:
651 break;
652 }
653
654 if (event->enabled) {
655 ret = -EEXIST;
656 goto end;
657 }
658 switch (event->priv->instrumentation) {
659 case LTTNG_KERNEL_ABI_TRACEPOINT:
660 lttng_fallthrough;
661 case LTTNG_KERNEL_ABI_SYSCALL:
662 ret = -EINVAL;
663 break;
664
665 case LTTNG_KERNEL_ABI_KPROBE:
666 lttng_fallthrough;
667 case LTTNG_KERNEL_ABI_UPROBE:
668 WRITE_ONCE(event->enabled, 1);
669 break;
670
671 case LTTNG_KERNEL_ABI_KRETPROBE:
672 ret = lttng_kretprobes_event_enable_state(event, 1);
673 break;
674
675 case LTTNG_KERNEL_ABI_FUNCTION:
676 lttng_fallthrough;
677 case LTTNG_KERNEL_ABI_NOOP:
678 lttng_fallthrough;
679 default:
680 WARN_ON_ONCE(1);
681 ret = -EINVAL;
682 }
683 end:
684 mutex_unlock(&sessions_mutex);
685 return ret;
686 }
687
688 int lttng_event_disable(struct lttng_kernel_event_common *event)
689 {
690 int ret = 0;
691
692 mutex_lock(&sessions_mutex);
693 switch (event->type) {
694 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
695 {
696 struct lttng_kernel_event_recorder *event_recorder =
697 container_of(event, struct lttng_kernel_event_recorder, parent);
698
699 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
700 ret = -EPERM;
701 goto end;
702 }
703 break;
704 }
705 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
706 switch (event->priv->instrumentation) {
707 case LTTNG_KERNEL_ABI_KRETPROBE:
708 ret = -EINVAL;
709 goto end;
710 default:
711 break;
712 }
713 break;
714 default:
715 break;
716 }
717
718 if (!event->enabled) {
719 ret = -EEXIST;
720 goto end;
721 }
722 switch (event->priv->instrumentation) {
723 case LTTNG_KERNEL_ABI_TRACEPOINT:
724 lttng_fallthrough;
725 case LTTNG_KERNEL_ABI_SYSCALL:
726 ret = -EINVAL;
727 break;
728
729 case LTTNG_KERNEL_ABI_KPROBE:
730 lttng_fallthrough;
731 case LTTNG_KERNEL_ABI_UPROBE:
732 WRITE_ONCE(event->enabled, 0);
733 break;
734
735 case LTTNG_KERNEL_ABI_KRETPROBE:
736 ret = lttng_kretprobes_event_enable_state(event, 0);
737 break;
738
739 case LTTNG_KERNEL_ABI_FUNCTION:
740 lttng_fallthrough;
741 case LTTNG_KERNEL_ABI_NOOP:
742 lttng_fallthrough;
743 default:
744 WARN_ON_ONCE(1);
745 ret = -EINVAL;
746 }
747 end:
748 mutex_unlock(&sessions_mutex);
749 return ret;
750 }
751
752 struct lttng_kernel_channel_buffer *lttng_channel_create(struct lttng_kernel_session *session,
753 const char *transport_name,
754 void *buf_addr,
755 size_t subbuf_size, size_t num_subbuf,
756 unsigned int switch_timer_interval,
757 unsigned int read_timer_interval,
758 enum channel_type channel_type)
759 {
760 struct lttng_kernel_channel_buffer *chan;
761 struct lttng_kernel_channel_buffer_private *chan_priv;
762 struct lttng_transport *transport = NULL;
763
764 mutex_lock(&sessions_mutex);
765 if (session->priv->been_active && channel_type != METADATA_CHANNEL)
766 goto active; /* Refuse to add channel to active session */
767 transport = lttng_transport_find(transport_name);
768 if (!transport) {
769 printk(KERN_WARNING "LTTng: transport %s not found\n",
770 transport_name);
771 goto notransport;
772 }
773 if (!try_module_get(transport->owner)) {
774 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
775 goto notransport;
776 }
777 chan = kzalloc(sizeof(struct lttng_kernel_channel_buffer), GFP_KERNEL);
778 if (!chan)
779 goto nomem;
780 chan_priv = kzalloc(sizeof(struct lttng_kernel_channel_buffer_private), GFP_KERNEL);
781 if (!chan_priv)
782 goto nomem_priv;
783 chan->priv = chan_priv;
784 chan_priv->pub = chan;
785 chan->parent.type = LTTNG_KERNEL_CHANNEL_TYPE_BUFFER;
786 chan->parent.session = session;
787 chan->priv->id = session->priv->free_chan_id++;
788 chan->ops = &transport->ops;
789 /*
790 * Note: the channel creation op already writes into the packet
791 * headers. Therefore the "chan" information used as input
792 * should be already accessible.
793 */
794 chan->priv->rb_chan = transport->ops.priv->channel_create(transport_name,
795 chan, buf_addr, subbuf_size, num_subbuf,
796 switch_timer_interval, read_timer_interval);
797 if (!chan->priv->rb_chan)
798 goto create_error;
799 chan->priv->parent.tstate = 1;
800 chan->parent.enabled = 1;
801 chan->priv->transport = transport;
802 chan->priv->channel_type = channel_type;
803 list_add(&chan->priv->node, &session->priv->chan);
804 mutex_unlock(&sessions_mutex);
805 return chan;
806
807 create_error:
808 kfree(chan_priv);
809 nomem_priv:
810 kfree(chan);
811 nomem:
812 if (transport)
813 module_put(transport->owner);
814 notransport:
815 active:
816 mutex_unlock(&sessions_mutex);
817 return NULL;
818 }
819
820 /*
821 * Only used internally at session destruction for per-cpu channels, and
822 * when metadata channel is released.
823 * Needs to be called with sessions mutex held.
824 */
825 static
826 void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan)
827 {
828 chan->ops->priv->channel_destroy(chan->priv->rb_chan);
829 module_put(chan->priv->transport->owner);
830 list_del(&chan->priv->node);
831 lttng_kernel_destroy_context(chan->priv->ctx);
832 kfree(chan->priv);
833 kfree(chan);
834 }
835
836 void lttng_metadata_channel_destroy(struct lttng_kernel_channel_buffer *chan)
837 {
838 BUG_ON(chan->priv->channel_type != METADATA_CHANNEL);
839
840 /* Protect the metadata cache with the sessions_mutex. */
841 mutex_lock(&sessions_mutex);
842 _lttng_channel_destroy(chan);
843 mutex_unlock(&sessions_mutex);
844 }
845 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
846
847 static
848 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
849 {
850 stream->finalized = 1;
851 wake_up_interruptible(&stream->read_wait);
852 }
853
854
855 /*
856 * Supports event creation while tracing session is active.
857 * Needs to be called with sessions mutex held.
858 */
859 struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
860 struct lttng_kernel_abi_event *event_param,
861 const struct lttng_kernel_event_desc *event_desc,
862 enum lttng_kernel_abi_instrumentation itype)
863 {
864 struct lttng_kernel_session *session = chan->parent.session;
865 struct lttng_kernel_event_recorder *event_recorder;
866 struct lttng_kernel_event_recorder_private *event_recorder_priv;
867 const char *event_name;
868 struct hlist_head *head;
869 int ret;
870
871 if (chan->priv->free_event_id == -1U) {
872 ret = -EMFILE;
873 goto full;
874 }
875
876 switch (itype) {
877 case LTTNG_KERNEL_ABI_TRACEPOINT:
878 event_name = event_desc->event_name;
879 break;
880
881 case LTTNG_KERNEL_ABI_KPROBE:
882 lttng_fallthrough;
883 case LTTNG_KERNEL_ABI_UPROBE:
884 lttng_fallthrough;
885 case LTTNG_KERNEL_ABI_KRETPROBE:
886 lttng_fallthrough;
887 case LTTNG_KERNEL_ABI_SYSCALL:
888 event_name = event_param->name;
889 break;
890
891 case LTTNG_KERNEL_ABI_FUNCTION:
892 lttng_fallthrough;
893 case LTTNG_KERNEL_ABI_NOOP:
894 lttng_fallthrough;
895 default:
896 WARN_ON_ONCE(1);
897 ret = -EINVAL;
898 goto type_error;
899 }
900
901 head = utils_borrow_hash_table_bucket(session->priv->events_ht.table,
902 LTTNG_EVENT_HT_SIZE, event_name);
903 lttng_hlist_for_each_entry(event_recorder_priv, head, hlist) {
904 WARN_ON_ONCE(!event_recorder_priv->parent.desc);
905 if (!strncmp(event_recorder_priv->parent.desc->event_name, event_name,
906 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
907 && chan == event_recorder_priv->pub->chan) {
908 ret = -EEXIST;
909 goto exist;
910 }
911 }
912
913 event_recorder = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
914 if (!event_recorder) {
915 ret = -ENOMEM;
916 goto cache_error;
917 }
918 event_recorder_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
919 if (!event_recorder_priv) {
920 ret = -ENOMEM;
921 goto cache_private_error;
922 }
923 event_recorder_priv->pub = event_recorder;
924 event_recorder_priv->parent.pub = &event_recorder->parent;
925 event_recorder->priv = event_recorder_priv;
926 event_recorder->parent.priv = &event_recorder_priv->parent;
927 event_recorder->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
928
929 event_recorder->parent.run_filter = lttng_kernel_interpret_event_filter;
930 event_recorder->chan = chan;
931 event_recorder->priv->id = chan->priv->free_event_id++;
932 event_recorder->priv->parent.instrumentation = itype;
933 INIT_LIST_HEAD(&event_recorder->priv->parent.filter_bytecode_runtime_head);
934 INIT_LIST_HEAD(&event_recorder->priv->parent.enablers_ref_head);
935
936 switch (itype) {
937 case LTTNG_KERNEL_ABI_TRACEPOINT:
938 /* Event will be enabled by enabler sync. */
939 event_recorder->parent.enabled = 0;
940 event_recorder->priv->parent.registered = 0;
941 event_recorder->priv->parent.desc = lttng_event_desc_get(event_name);
942 if (!event_recorder->priv->parent.desc) {
943 ret = -ENOENT;
944 goto register_error;
945 }
946 /* Populate lttng_event structure before event registration. */
947 smp_wmb();
948 break;
949
950 case LTTNG_KERNEL_ABI_KPROBE:
951 /*
952 * Needs to be explicitly enabled after creation, since
953 * we may want to apply filters.
954 */
955 event_recorder->parent.enabled = 0;
956 event_recorder->priv->parent.registered = 1;
957 /*
958 * Populate lttng_event structure before event
959 * registration.
960 */
961 smp_wmb();
962 ret = lttng_kprobes_register_event(event_name,
963 event_param->u.kprobe.symbol_name,
964 event_param->u.kprobe.offset,
965 event_param->u.kprobe.addr,
966 event_recorder);
967 if (ret) {
968 ret = -EINVAL;
969 goto register_error;
970 }
971 ret = try_module_get(event_recorder->priv->parent.desc->owner);
972 WARN_ON_ONCE(!ret);
973 break;
974
975 case LTTNG_KERNEL_ABI_KRETPROBE:
976 {
977 struct lttng_kernel_event_recorder *event_recorder_return;
978 struct lttng_kernel_event_recorder_private *event_recorder_return_priv;
979
980 /* kretprobe defines 2 events */
981 /*
982 * Needs to be explicitly enabled after creation, since
983 * we may want to apply filters.
984 */
985 event_recorder->parent.enabled = 0;
986 event_recorder->priv->parent.registered = 1;
987
988 event_recorder_return = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
989 if (!event_recorder_return) {
990 ret = -ENOMEM;
991 goto register_error;
992 }
993 event_recorder_return_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
994 if (!event_recorder_return_priv) {
995 kmem_cache_free(event_recorder_cache, event_recorder_return);
996 ret = -ENOMEM;
997 goto register_error;
998 }
999 event_recorder_return_priv->pub = event_recorder_return;
1000 event_recorder_return_priv->parent.pub = &event_recorder_return->parent;
1001 event_recorder_return->priv = event_recorder_return_priv;
1002 event_recorder_return->parent.priv = &event_recorder_return_priv->parent;
1003 event_recorder_return->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
1004
1005 event_recorder_return->parent.run_filter = lttng_kernel_interpret_event_filter;
1006 event_recorder_return->chan = chan;
1007 event_recorder_return->priv->id = chan->priv->free_event_id++;
1008 event_recorder_return->priv->parent.instrumentation = itype;
1009 event_recorder_return->parent.enabled = 0;
1010 event_recorder_return->priv->parent.registered = 1;
1011 INIT_LIST_HEAD(&event_recorder_return->priv->parent.filter_bytecode_runtime_head);
1012 INIT_LIST_HEAD(&event_recorder_return->priv->parent.enablers_ref_head);
1013 /*
1014 * Populate lttng_event structure before kretprobe registration.
1015 */
1016 smp_wmb();
1017 ret = lttng_kretprobes_register(event_name,
1018 event_param->u.kretprobe.symbol_name,
1019 event_param->u.kretprobe.offset,
1020 event_param->u.kretprobe.addr,
1021 event_recorder, event_recorder_return);
1022 if (ret) {
1023 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
1024 kmem_cache_free(event_recorder_cache, event_recorder_return);
1025 ret = -EINVAL;
1026 goto register_error;
1027 }
1028 /* Take 2 refs on the module: one per event. */
1029 ret = try_module_get(event_recorder->priv->parent.desc->owner);
1030 WARN_ON_ONCE(!ret);
1031 ret = try_module_get(event_recorder_return->priv->parent.desc->owner);
1032 WARN_ON_ONCE(!ret);
1033 ret = _lttng_event_metadata_statedump(chan->parent.session, chan,
1034 event_recorder_return);
1035 WARN_ON_ONCE(ret > 0);
1036 if (ret) {
1037 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
1038 kmem_cache_free(event_recorder_cache, event_recorder_return);
1039 module_put(event_recorder_return->priv->parent.desc->owner);
1040 module_put(event_recorder->priv->parent.desc->owner);
1041 goto statedump_error;
1042 }
1043 list_add(&event_recorder_return->priv->node, &chan->parent.session->priv->events);
1044 break;
1045 }
1046
1047 case LTTNG_KERNEL_ABI_SYSCALL:
1048 /*
1049 * Needs to be explicitly enabled after creation, since
1050 * we may want to apply filters.
1051 */
1052 event_recorder->parent.enabled = 0;
1053 event_recorder->priv->parent.registered = 0;
1054 event_recorder->priv->parent.desc = event_desc;
1055 switch (event_param->u.syscall.entryexit) {
1056 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1057 ret = -EINVAL;
1058 goto register_error;
1059 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1060 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1061 break;
1062 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1063 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1064 break;
1065 }
1066 switch (event_param->u.syscall.abi) {
1067 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1068 ret = -EINVAL;
1069 goto register_error;
1070 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1071 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1072 break;
1073 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1074 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1075 break;
1076 }
1077 if (!event_recorder->priv->parent.desc) {
1078 ret = -EINVAL;
1079 goto register_error;
1080 }
1081 break;
1082
1083 case LTTNG_KERNEL_ABI_UPROBE:
1084 /*
1085 * Needs to be explicitly enabled after creation, since
1086 * we may want to apply filters.
1087 */
1088 event_recorder->parent.enabled = 0;
1089 event_recorder->priv->parent.registered = 1;
1090
1091 /*
1092 * Populate lttng_event structure before event
1093 * registration.
1094 */
1095 smp_wmb();
1096
1097 ret = lttng_uprobes_register_event(event_param->name,
1098 event_param->u.uprobe.fd,
1099 event_recorder);
1100 if (ret)
1101 goto register_error;
1102 ret = try_module_get(event_recorder->priv->parent.desc->owner);
1103 WARN_ON_ONCE(!ret);
1104 break;
1105
1106 case LTTNG_KERNEL_ABI_FUNCTION:
1107 lttng_fallthrough;
1108 case LTTNG_KERNEL_ABI_NOOP:
1109 lttng_fallthrough;
1110 default:
1111 WARN_ON_ONCE(1);
1112 ret = -EINVAL;
1113 goto register_error;
1114 }
1115 ret = _lttng_event_metadata_statedump(chan->parent.session, chan, event_recorder);
1116 WARN_ON_ONCE(ret > 0);
1117 if (ret) {
1118 goto statedump_error;
1119 }
1120 hlist_add_head(&event_recorder->priv->hlist, head);
1121 list_add(&event_recorder->priv->node, &chan->parent.session->priv->events);
1122 return event_recorder;
1123
1124 statedump_error:
1125 /* If a statedump error occurs, events will not be readable. */
1126 register_error:
1127 kmem_cache_free(event_recorder_private_cache, event_recorder_priv);
1128 cache_private_error:
1129 kmem_cache_free(event_recorder_cache, event_recorder);
1130 cache_error:
1131 exist:
1132 type_error:
1133 full:
1134 return ERR_PTR(ret);
1135 }
1136
1137 struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
1138 const struct lttng_kernel_event_desc *event_desc,
1139 uint64_t token, uint64_t error_counter_index,
1140 struct lttng_event_notifier_group *event_notifier_group,
1141 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1142 enum lttng_kernel_abi_instrumentation itype)
1143 {
1144 struct lttng_kernel_event_notifier *event_notifier;
1145 struct lttng_kernel_event_notifier_private *event_notifier_priv;
1146 struct lttng_counter *error_counter;
1147 const char *event_name;
1148 struct hlist_head *head;
1149 int ret;
1150
1151 switch (itype) {
1152 case LTTNG_KERNEL_ABI_TRACEPOINT:
1153 event_name = event_desc->event_name;
1154 break;
1155
1156 case LTTNG_KERNEL_ABI_KPROBE:
1157 lttng_fallthrough;
1158 case LTTNG_KERNEL_ABI_UPROBE:
1159 lttng_fallthrough;
1160 case LTTNG_KERNEL_ABI_SYSCALL:
1161 event_name = event_notifier_param->event.name;
1162 break;
1163
1164 case LTTNG_KERNEL_ABI_KRETPROBE:
1165 lttng_fallthrough;
1166 case LTTNG_KERNEL_ABI_FUNCTION:
1167 lttng_fallthrough;
1168 case LTTNG_KERNEL_ABI_NOOP:
1169 lttng_fallthrough;
1170 default:
1171 WARN_ON_ONCE(1);
1172 ret = -EINVAL;
1173 goto type_error;
1174 }
1175
1176 head = utils_borrow_hash_table_bucket(event_notifier_group->event_notifiers_ht.table,
1177 LTTNG_EVENT_NOTIFIER_HT_SIZE, event_name);
1178 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
1179 WARN_ON_ONCE(!event_notifier_priv->parent.desc);
1180 if (!strncmp(event_notifier_priv->parent.desc->event_name, event_name,
1181 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
1182 && event_notifier_group == event_notifier_priv->group
1183 && token == event_notifier_priv->parent.user_token) {
1184 ret = -EEXIST;
1185 goto exist;
1186 }
1187 }
1188
1189 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
1190 if (!event_notifier) {
1191 ret = -ENOMEM;
1192 goto cache_error;
1193 }
1194 event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
1195 if (!event_notifier_priv) {
1196 ret = -ENOMEM;
1197 goto cache_private_error;
1198 }
1199 event_notifier_priv->pub = event_notifier;
1200 event_notifier_priv->parent.pub = &event_notifier->parent;
1201 event_notifier->priv = event_notifier_priv;
1202 event_notifier->parent.priv = &event_notifier_priv->parent;
1203 event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
1204
1205 event_notifier->priv->group = event_notifier_group;
1206 event_notifier->priv->parent.user_token = token;
1207 event_notifier->priv->error_counter_index = error_counter_index;
1208 event_notifier->priv->num_captures = 0;
1209 event_notifier->priv->parent.instrumentation = itype;
1210 event_notifier->notification_send = lttng_event_notifier_notification_send;
1211 INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
1212 INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
1213 INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
1214 event_notifier->parent.run_filter = lttng_kernel_interpret_event_filter;
1215
1216 switch (itype) {
1217 case LTTNG_KERNEL_ABI_TRACEPOINT:
1218 /* Event will be enabled by enabler sync. */
1219 event_notifier->parent.enabled = 0;
1220 event_notifier->priv->parent.registered = 0;
1221 event_notifier->priv->parent.desc = lttng_event_desc_get(event_name);
1222 if (!event_notifier->priv->parent.desc) {
1223 ret = -ENOENT;
1224 goto register_error;
1225 }
1226 /* Populate lttng_event_notifier structure before event registration. */
1227 smp_wmb();
1228 break;
1229
1230 case LTTNG_KERNEL_ABI_KPROBE:
1231 /*
1232 * Needs to be explicitly enabled after creation, since
1233 * we may want to apply filters.
1234 */
1235 event_notifier->parent.enabled = 0;
1236 event_notifier->priv->parent.registered = 1;
1237 /*
1238 * Populate lttng_event_notifier structure before event
1239 * registration.
1240 */
1241 smp_wmb();
1242 ret = lttng_kprobes_register_event_notifier(
1243 event_notifier_param->event.u.kprobe.symbol_name,
1244 event_notifier_param->event.u.kprobe.offset,
1245 event_notifier_param->event.u.kprobe.addr,
1246 event_notifier);
1247 if (ret) {
1248 ret = -EINVAL;
1249 goto register_error;
1250 }
1251 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1252 WARN_ON_ONCE(!ret);
1253 break;
1254
1255 case LTTNG_KERNEL_ABI_SYSCALL:
1256 /*
1257 * Needs to be explicitly enabled after creation, since
1258 * we may want to apply filters.
1259 */
1260 event_notifier->parent.enabled = 0;
1261 event_notifier->priv->parent.registered = 0;
1262 event_notifier->priv->parent.desc = event_desc;
1263 switch (event_notifier_param->event.u.syscall.entryexit) {
1264 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1265 ret = -EINVAL;
1266 goto register_error;
1267 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1268 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1269 break;
1270 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1271 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1272 break;
1273 }
1274 switch (event_notifier_param->event.u.syscall.abi) {
1275 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1276 ret = -EINVAL;
1277 goto register_error;
1278 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1279 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1280 break;
1281 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1282 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1283 break;
1284 }
1285
1286 if (!event_notifier->priv->parent.desc) {
1287 ret = -EINVAL;
1288 goto register_error;
1289 }
1290 break;
1291
1292 case LTTNG_KERNEL_ABI_UPROBE:
1293 /*
1294 * Needs to be explicitly enabled after creation, since
1295 * we may want to apply filters.
1296 */
1297 event_notifier->parent.enabled = 0;
1298 event_notifier->priv->parent.registered = 1;
1299
1300 /*
1301 * Populate lttng_event_notifier structure before
1302 * event_notifier registration.
1303 */
1304 smp_wmb();
1305
1306 ret = lttng_uprobes_register_event_notifier(
1307 event_notifier_param->event.name,
1308 event_notifier_param->event.u.uprobe.fd,
1309 event_notifier);
1310 if (ret)
1311 goto register_error;
1312 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1313 WARN_ON_ONCE(!ret);
1314 break;
1315
1316 case LTTNG_KERNEL_ABI_KRETPROBE:
1317 lttng_fallthrough;
1318 case LTTNG_KERNEL_ABI_FUNCTION:
1319 lttng_fallthrough;
1320 case LTTNG_KERNEL_ABI_NOOP:
1321 lttng_fallthrough;
1322 default:
1323 WARN_ON_ONCE(1);
1324 ret = -EINVAL;
1325 goto register_error;
1326 }
1327
1328 list_add(&event_notifier->priv->node, &event_notifier_group->event_notifiers_head);
1329 hlist_add_head(&event_notifier->priv->hlist, head);
1330
1331 /*
1332 * Clear the error counter bucket. The sessiond keeps track of which
1333 * bucket is currently in use. We trust it. The session lock
1334 * synchronizes against concurrent creation of the error
1335 * counter.
1336 */
1337 error_counter = event_notifier_group->error_counter;
1338 if (error_counter) {
1339 size_t dimension_index[1];
1340
1341 /*
1342 * Check that the index is within the boundary of the counter.
1343 */
1344 if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
1345 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1346 event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
1347 ret = -EINVAL;
1348 goto register_error;
1349 }
1350
1351 dimension_index[0] = event_notifier->priv->error_counter_index;
1352 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1353 if (ret) {
1354 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1355 event_notifier->priv->error_counter_index);
1356 goto register_error;
1357 }
1358 }
1359
1360 return event_notifier;
1361
1362 register_error:
1363 kmem_cache_free(event_notifier_private_cache, event_notifier_priv);
1364 cache_private_error:
1365 kmem_cache_free(event_notifier_cache, event_notifier);
1366 cache_error:
1367 exist:
1368 type_error:
1369 return ERR_PTR(ret);
1370 }
1371
1372 int lttng_kernel_counter_read(struct lttng_counter *counter,
1373 const size_t *dim_indexes, int32_t cpu,
1374 int64_t *val, bool *overflow, bool *underflow)
1375 {
1376 return counter->ops->counter_read(counter->counter, dim_indexes,
1377 cpu, val, overflow, underflow);
1378 }
1379
1380 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1381 const size_t *dim_indexes, int64_t *val,
1382 bool *overflow, bool *underflow)
1383 {
1384 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1385 val, overflow, underflow);
1386 }
1387
1388 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1389 const size_t *dim_indexes)
1390 {
1391 return counter->ops->counter_clear(counter->counter, dim_indexes);
1392 }
1393
1394 struct lttng_kernel_event_recorder *lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
1395 struct lttng_kernel_abi_event *event_param,
1396 const struct lttng_kernel_event_desc *event_desc,
1397 enum lttng_kernel_abi_instrumentation itype)
1398 {
1399 struct lttng_kernel_event_recorder *event;
1400
1401 mutex_lock(&sessions_mutex);
1402 event = _lttng_kernel_event_recorder_create(chan, event_param, event_desc, itype);
1403 mutex_unlock(&sessions_mutex);
1404 return event;
1405 }
1406
1407 struct lttng_kernel_event_notifier *lttng_event_notifier_create(
1408 const struct lttng_kernel_event_desc *event_desc,
1409 uint64_t id, uint64_t error_counter_index,
1410 struct lttng_event_notifier_group *event_notifier_group,
1411 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1412 enum lttng_kernel_abi_instrumentation itype)
1413 {
1414 struct lttng_kernel_event_notifier *event_notifier;
1415
1416 mutex_lock(&sessions_mutex);
1417 event_notifier = _lttng_event_notifier_create(event_desc, id,
1418 error_counter_index, event_notifier_group,
1419 event_notifier_param, itype);
1420 mutex_unlock(&sessions_mutex);
1421 return event_notifier;
1422 }
1423
1424 /* Only used for tracepoints for now. */
1425 static
1426 void register_event(struct lttng_kernel_event_recorder *event_recorder)
1427 {
1428 const struct lttng_kernel_event_desc *desc;
1429 int ret = -EINVAL;
1430
1431 WARN_ON_ONCE(event_recorder->priv->parent.registered);
1432
1433 desc = event_recorder->priv->parent.desc;
1434 switch (event_recorder->priv->parent.instrumentation) {
1435 case LTTNG_KERNEL_ABI_TRACEPOINT:
1436 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1437 desc->tp_class->probe_callback,
1438 event_recorder);
1439 break;
1440
1441 case LTTNG_KERNEL_ABI_SYSCALL:
1442 ret = lttng_syscall_filter_enable_event(event_recorder->chan, event_recorder);
1443 break;
1444
1445 case LTTNG_KERNEL_ABI_KPROBE:
1446 lttng_fallthrough;
1447 case LTTNG_KERNEL_ABI_UPROBE:
1448 lttng_fallthrough;
1449 case LTTNG_KERNEL_ABI_KRETPROBE:
1450 ret = 0;
1451 break;
1452
1453 case LTTNG_KERNEL_ABI_FUNCTION:
1454 lttng_fallthrough;
1455 case LTTNG_KERNEL_ABI_NOOP:
1456 lttng_fallthrough;
1457 default:
1458 WARN_ON_ONCE(1);
1459 }
1460 if (!ret)
1461 event_recorder->priv->parent.registered = 1;
1462 }
1463
1464 /*
1465 * Only used internally at session destruction.
1466 */
1467 static
1468 void unregister_event(struct lttng_kernel_event_recorder *event_recorder)
1469 {
1470 struct lttng_kernel_event_common_private *event_priv = &event_recorder->priv->parent;
1471 const struct lttng_kernel_event_desc *desc;
1472 int ret = -EINVAL;
1473
1474 WARN_ON_ONCE(!event_priv->registered);
1475
1476 desc = event_priv->desc;
1477 switch (event_priv->instrumentation) {
1478 case LTTNG_KERNEL_ABI_TRACEPOINT:
1479 ret = lttng_wrapper_tracepoint_probe_unregister(event_priv->desc->event_kname,
1480 event_priv->desc->tp_class->probe_callback,
1481 event_recorder);
1482 break;
1483
1484 case LTTNG_KERNEL_ABI_KPROBE:
1485 lttng_kprobes_unregister_event(event_recorder);
1486 ret = 0;
1487 break;
1488
1489 case LTTNG_KERNEL_ABI_KRETPROBE:
1490 lttng_kretprobes_unregister(event_recorder);
1491 ret = 0;
1492 break;
1493
1494 case LTTNG_KERNEL_ABI_SYSCALL:
1495 ret = lttng_syscall_filter_disable_event(event_recorder->chan, event_recorder);
1496 break;
1497
1498 case LTTNG_KERNEL_ABI_NOOP:
1499 ret = 0;
1500 break;
1501
1502 case LTTNG_KERNEL_ABI_UPROBE:
1503 lttng_uprobes_unregister_event(event_recorder);
1504 ret = 0;
1505 break;
1506
1507 case LTTNG_KERNEL_ABI_FUNCTION:
1508 lttng_fallthrough;
1509 default:
1510 WARN_ON_ONCE(1);
1511 }
1512 WARN_ON_ONCE(ret);
1513 if (!ret)
1514 event_priv->registered = 0;
1515 }
1516
1517 static
1518 void _lttng_event_unregister(struct lttng_kernel_event_recorder *event_recorder)
1519 {
1520 if (event_recorder->priv->parent.registered)
1521 unregister_event(event_recorder);
1522 }
1523
1524 /* Only used for tracepoints for now. */
1525 static
1526 void register_event_notifier(struct lttng_kernel_event_notifier *event_notifier)
1527 {
1528 const struct lttng_kernel_event_desc *desc;
1529 int ret = -EINVAL;
1530
1531 WARN_ON_ONCE(event_notifier->priv->parent.registered);
1532
1533 desc = event_notifier->priv->parent.desc;
1534 switch (event_notifier->priv->parent.instrumentation) {
1535 case LTTNG_KERNEL_ABI_TRACEPOINT:
1536 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1537 desc->tp_class->probe_callback,
1538 event_notifier);
1539 break;
1540
1541 case LTTNG_KERNEL_ABI_SYSCALL:
1542 ret = lttng_syscall_filter_enable_event_notifier(event_notifier);
1543 break;
1544
1545 case LTTNG_KERNEL_ABI_KPROBE:
1546 lttng_fallthrough;
1547 case LTTNG_KERNEL_ABI_UPROBE:
1548 ret = 0;
1549 break;
1550
1551 case LTTNG_KERNEL_ABI_KRETPROBE:
1552 lttng_fallthrough;
1553 case LTTNG_KERNEL_ABI_FUNCTION:
1554 lttng_fallthrough;
1555 case LTTNG_KERNEL_ABI_NOOP:
1556 lttng_fallthrough;
1557 default:
1558 WARN_ON_ONCE(1);
1559 }
1560 if (!ret)
1561 event_notifier->priv->parent.registered = 1;
1562 }
1563
1564 static
1565 int unregister_event_notifier(struct lttng_kernel_event_notifier *event_notifier)
1566 {
1567 const struct lttng_kernel_event_desc *desc;
1568 int ret = -EINVAL;
1569
1570 WARN_ON_ONCE(!event_notifier->priv->parent.registered);
1571
1572 desc = event_notifier->priv->parent.desc;
1573 switch (event_notifier->priv->parent.instrumentation) {
1574 case LTTNG_KERNEL_ABI_TRACEPOINT:
1575 ret = lttng_wrapper_tracepoint_probe_unregister(event_notifier->priv->parent.desc->event_kname,
1576 event_notifier->priv->parent.desc->tp_class->probe_callback,
1577 event_notifier);
1578 break;
1579
1580 case LTTNG_KERNEL_ABI_KPROBE:
1581 lttng_kprobes_unregister_event_notifier(event_notifier);
1582 ret = 0;
1583 break;
1584
1585 case LTTNG_KERNEL_ABI_UPROBE:
1586 lttng_uprobes_unregister_event_notifier(event_notifier);
1587 ret = 0;
1588 break;
1589
1590 case LTTNG_KERNEL_ABI_SYSCALL:
1591 ret = lttng_syscall_filter_disable_event_notifier(event_notifier);
1592 break;
1593
1594 case LTTNG_KERNEL_ABI_KRETPROBE:
1595 lttng_fallthrough;
1596 case LTTNG_KERNEL_ABI_FUNCTION:
1597 lttng_fallthrough;
1598 case LTTNG_KERNEL_ABI_NOOP:
1599 lttng_fallthrough;
1600 default:
1601 WARN_ON_ONCE(1);
1602 }
1603 if (!ret)
1604 event_notifier->priv->parent.registered = 0;
1605 return ret;
1606 }
1607
1608 static
1609 void _lttng_event_notifier_unregister(struct lttng_kernel_event_notifier *event_notifier)
1610 {
1611 if (event_notifier->priv->parent.registered)
1612 unregister_event_notifier(event_notifier);
1613 }
1614
1615 /*
1616 * Only used internally at session destruction.
1617 */
1618 static
1619 void _lttng_event_destroy(struct lttng_kernel_event_common *event)
1620 {
1621 struct lttng_kernel_event_common_private *event_priv = event->priv;
1622 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1623
1624 lttng_free_event_filter_runtime(event);
1625 /* Free event enabler refs */
1626 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1627 &event_priv->enablers_ref_head, node)
1628 kfree(enabler_ref);
1629
1630 switch (event->type) {
1631 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1632 {
1633 struct lttng_kernel_event_recorder *event_recorder =
1634 container_of(event, struct lttng_kernel_event_recorder, parent);
1635
1636 switch (event_priv->instrumentation) {
1637 case LTTNG_KERNEL_ABI_TRACEPOINT:
1638 lttng_event_desc_put(event_priv->desc);
1639 break;
1640
1641 case LTTNG_KERNEL_ABI_KPROBE:
1642 module_put(event_priv->desc->owner);
1643 lttng_kprobes_destroy_event_private(event_recorder);
1644 break;
1645
1646 case LTTNG_KERNEL_ABI_KRETPROBE:
1647 module_put(event_priv->desc->owner);
1648 lttng_kretprobes_destroy_private(event_recorder);
1649 break;
1650
1651 case LTTNG_KERNEL_ABI_SYSCALL:
1652 break;
1653
1654 case LTTNG_KERNEL_ABI_UPROBE:
1655 module_put(event_priv->desc->owner);
1656 lttng_uprobes_destroy_event_private(event_recorder);
1657 break;
1658
1659 case LTTNG_KERNEL_ABI_FUNCTION:
1660 lttng_fallthrough;
1661 case LTTNG_KERNEL_ABI_NOOP:
1662 lttng_fallthrough;
1663 default:
1664 WARN_ON_ONCE(1);
1665 }
1666 list_del(&event_recorder->priv->node);
1667 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
1668 kmem_cache_free(event_recorder_cache, event_recorder);
1669 break;
1670 }
1671 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1672 {
1673 struct lttng_kernel_event_notifier *event_notifier =
1674 container_of(event, struct lttng_kernel_event_notifier, parent);
1675
1676 switch (event_notifier->priv->parent.instrumentation) {
1677 case LTTNG_KERNEL_ABI_TRACEPOINT:
1678 lttng_event_desc_put(event_notifier->priv->parent.desc);
1679 break;
1680
1681 case LTTNG_KERNEL_ABI_KPROBE:
1682 module_put(event_notifier->priv->parent.desc->owner);
1683 lttng_kprobes_destroy_event_notifier_private(event_notifier);
1684 break;
1685
1686 case LTTNG_KERNEL_ABI_SYSCALL:
1687 break;
1688
1689 case LTTNG_KERNEL_ABI_UPROBE:
1690 module_put(event_notifier->priv->parent.desc->owner);
1691 lttng_uprobes_destroy_event_notifier_private(event_notifier);
1692 break;
1693
1694 case LTTNG_KERNEL_ABI_KRETPROBE:
1695 lttng_fallthrough;
1696 case LTTNG_KERNEL_ABI_FUNCTION:
1697 lttng_fallthrough;
1698 case LTTNG_KERNEL_ABI_NOOP:
1699 lttng_fallthrough;
1700 default:
1701 WARN_ON_ONCE(1);
1702 }
1703 list_del(&event_notifier->priv->node);
1704 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1705 kmem_cache_free(event_notifier_cache, event_notifier);
1706 break;
1707 }
1708 default:
1709 WARN_ON_ONCE(1);
1710 }
1711 }
1712
1713 struct lttng_kernel_id_tracker *get_tracker(struct lttng_kernel_session *session,
1714 enum tracker_type tracker_type)
1715 {
1716 switch (tracker_type) {
1717 case TRACKER_PID:
1718 return &session->pid_tracker;
1719 case TRACKER_VPID:
1720 return &session->vpid_tracker;
1721 case TRACKER_UID:
1722 return &session->uid_tracker;
1723 case TRACKER_VUID:
1724 return &session->vuid_tracker;
1725 case TRACKER_GID:
1726 return &session->gid_tracker;
1727 case TRACKER_VGID:
1728 return &session->vgid_tracker;
1729 default:
1730 WARN_ON_ONCE(1);
1731 return NULL;
1732 }
1733 }
1734
1735 int lttng_session_track_id(struct lttng_kernel_session *session,
1736 enum tracker_type tracker_type, int id)
1737 {
1738 struct lttng_kernel_id_tracker *tracker;
1739 int ret;
1740
1741 tracker = get_tracker(session, tracker_type);
1742 if (!tracker)
1743 return -EINVAL;
1744 if (id < -1)
1745 return -EINVAL;
1746 mutex_lock(&sessions_mutex);
1747 if (id == -1) {
1748 /* track all ids: destroy tracker. */
1749 lttng_id_tracker_destroy(tracker, true);
1750 ret = 0;
1751 } else {
1752 ret = lttng_id_tracker_add(tracker, id);
1753 }
1754 mutex_unlock(&sessions_mutex);
1755 return ret;
1756 }
1757
1758 int lttng_session_untrack_id(struct lttng_kernel_session *session,
1759 enum tracker_type tracker_type, int id)
1760 {
1761 struct lttng_kernel_id_tracker *tracker;
1762 int ret;
1763
1764 tracker = get_tracker(session, tracker_type);
1765 if (!tracker)
1766 return -EINVAL;
1767 if (id < -1)
1768 return -EINVAL;
1769 mutex_lock(&sessions_mutex);
1770 if (id == -1) {
1771 /* untrack all ids: replace by empty tracker. */
1772 ret = lttng_id_tracker_empty_set(tracker);
1773 } else {
1774 ret = lttng_id_tracker_del(tracker, id);
1775 }
1776 mutex_unlock(&sessions_mutex);
1777 return ret;
1778 }
1779
1780 static
1781 void *id_list_start(struct seq_file *m, loff_t *pos)
1782 {
1783 struct lttng_kernel_id_tracker *id_tracker = m->private;
1784 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1785 struct lttng_id_hash_node *e;
1786 int iter = 0, i;
1787
1788 mutex_lock(&sessions_mutex);
1789 if (id_tracker_p) {
1790 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1791 struct hlist_head *head = &id_tracker_p->id_hash[i];
1792
1793 lttng_hlist_for_each_entry(e, head, hlist) {
1794 if (iter++ >= *pos)
1795 return e;
1796 }
1797 }
1798 } else {
1799 /* ID tracker disabled. */
1800 if (iter >= *pos && iter == 0) {
1801 return id_tracker_p; /* empty tracker */
1802 }
1803 iter++;
1804 }
1805 /* End of list */
1806 return NULL;
1807 }
1808
1809 /* Called with sessions_mutex held. */
1810 static
1811 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1812 {
1813 struct lttng_kernel_id_tracker *id_tracker = m->private;
1814 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1815 struct lttng_id_hash_node *e;
1816 int iter = 0, i;
1817
1818 (*ppos)++;
1819 if (id_tracker_p) {
1820 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1821 struct hlist_head *head = &id_tracker_p->id_hash[i];
1822
1823 lttng_hlist_for_each_entry(e, head, hlist) {
1824 if (iter++ >= *ppos)
1825 return e;
1826 }
1827 }
1828 } else {
1829 /* ID tracker disabled. */
1830 if (iter >= *ppos && iter == 0)
1831 return p; /* empty tracker */
1832 iter++;
1833 }
1834
1835 /* End of list */
1836 return NULL;
1837 }
1838
1839 static
1840 void id_list_stop(struct seq_file *m, void *p)
1841 {
1842 mutex_unlock(&sessions_mutex);
1843 }
1844
1845 static
1846 int id_list_show(struct seq_file *m, void *p)
1847 {
1848 struct lttng_kernel_id_tracker *id_tracker = m->private;
1849 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1850 int id;
1851
1852 if (p == id_tracker_p) {
1853 /* Tracker disabled. */
1854 id = -1;
1855 } else {
1856 const struct lttng_id_hash_node *e = p;
1857
1858 id = lttng_id_tracker_get_node_id(e);
1859 }
1860 switch (id_tracker->priv->tracker_type) {
1861 case TRACKER_PID:
1862 seq_printf(m, "process { pid = %d; };\n", id);
1863 break;
1864 case TRACKER_VPID:
1865 seq_printf(m, "process { vpid = %d; };\n", id);
1866 break;
1867 case TRACKER_UID:
1868 seq_printf(m, "user { uid = %d; };\n", id);
1869 break;
1870 case TRACKER_VUID:
1871 seq_printf(m, "user { vuid = %d; };\n", id);
1872 break;
1873 case TRACKER_GID:
1874 seq_printf(m, "group { gid = %d; };\n", id);
1875 break;
1876 case TRACKER_VGID:
1877 seq_printf(m, "group { vgid = %d; };\n", id);
1878 break;
1879 default:
1880 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1881 }
1882 return 0;
1883 }
1884
1885 static
1886 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1887 .start = id_list_start,
1888 .next = id_list_next,
1889 .stop = id_list_stop,
1890 .show = id_list_show,
1891 };
1892
1893 static
1894 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1895 {
1896 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1897 }
1898
1899 static
1900 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1901 {
1902 struct seq_file *m = file->private_data;
1903 struct lttng_kernel_id_tracker *id_tracker = m->private;
1904 int ret;
1905
1906 WARN_ON_ONCE(!id_tracker);
1907 ret = seq_release(inode, file);
1908 if (!ret)
1909 fput(id_tracker->priv->session->priv->file);
1910 return ret;
1911 }
1912
1913 const struct file_operations lttng_tracker_ids_list_fops = {
1914 .owner = THIS_MODULE,
1915 .open = lttng_tracker_ids_list_open,
1916 .read = seq_read,
1917 .llseek = seq_lseek,
1918 .release = lttng_tracker_ids_list_release,
1919 };
1920
1921 int lttng_session_list_tracker_ids(struct lttng_kernel_session *session,
1922 enum tracker_type tracker_type)
1923 {
1924 struct file *tracker_ids_list_file;
1925 struct seq_file *m;
1926 int file_fd, ret;
1927
1928 file_fd = lttng_get_unused_fd();
1929 if (file_fd < 0) {
1930 ret = file_fd;
1931 goto fd_error;
1932 }
1933
1934 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1935 &lttng_tracker_ids_list_fops,
1936 NULL, O_RDWR);
1937 if (IS_ERR(tracker_ids_list_file)) {
1938 ret = PTR_ERR(tracker_ids_list_file);
1939 goto file_error;
1940 }
1941 if (!atomic_long_add_unless(&session->priv->file->f_count, 1, LONG_MAX)) {
1942 ret = -EOVERFLOW;
1943 goto refcount_error;
1944 }
1945 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1946 if (ret < 0)
1947 goto open_error;
1948 m = tracker_ids_list_file->private_data;
1949
1950 m->private = get_tracker(session, tracker_type);
1951 BUG_ON(!m->private);
1952 fd_install(file_fd, tracker_ids_list_file);
1953
1954 return file_fd;
1955
1956 open_error:
1957 atomic_long_dec(&session->priv->file->f_count);
1958 refcount_error:
1959 fput(tracker_ids_list_file);
1960 file_error:
1961 put_unused_fd(file_fd);
1962 fd_error:
1963 return ret;
1964 }
1965
1966 /*
1967 * Enabler management.
1968 */
1969 static
1970 int lttng_match_enabler_star_glob(const char *desc_name,
1971 const char *pattern)
1972 {
1973 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1974 desc_name, LTTNG_SIZE_MAX))
1975 return 0;
1976 return 1;
1977 }
1978
1979 static
1980 int lttng_match_enabler_name(const char *desc_name,
1981 const char *name)
1982 {
1983 if (strcmp(desc_name, name))
1984 return 0;
1985 return 1;
1986 }
1987
1988 int lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
1989 struct lttng_enabler *enabler)
1990 {
1991 const char *desc_name, *enabler_name;
1992 bool compat = false, entry = false;
1993
1994 enabler_name = enabler->event_param.name;
1995 switch (enabler->event_param.instrumentation) {
1996 case LTTNG_KERNEL_ABI_TRACEPOINT:
1997 desc_name = desc->event_name;
1998 switch (enabler->format_type) {
1999 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2000 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2001 case LTTNG_ENABLER_FORMAT_NAME:
2002 return lttng_match_enabler_name(desc_name, enabler_name);
2003 default:
2004 return -EINVAL;
2005 }
2006 break;
2007
2008 case LTTNG_KERNEL_ABI_SYSCALL:
2009 desc_name = desc->event_name;
2010 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
2011 desc_name += strlen("compat_");
2012 compat = true;
2013 }
2014 if (!strncmp(desc_name, "syscall_exit_",
2015 strlen("syscall_exit_"))) {
2016 desc_name += strlen("syscall_exit_");
2017 } else if (!strncmp(desc_name, "syscall_entry_",
2018 strlen("syscall_entry_"))) {
2019 desc_name += strlen("syscall_entry_");
2020 entry = true;
2021 } else {
2022 WARN_ON_ONCE(1);
2023 return -EINVAL;
2024 }
2025 switch (enabler->event_param.u.syscall.entryexit) {
2026 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
2027 break;
2028 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
2029 if (!entry)
2030 return 0;
2031 break;
2032 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
2033 if (entry)
2034 return 0;
2035 break;
2036 default:
2037 return -EINVAL;
2038 }
2039 switch (enabler->event_param.u.syscall.abi) {
2040 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
2041 break;
2042 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
2043 if (compat)
2044 return 0;
2045 break;
2046 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
2047 if (!compat)
2048 return 0;
2049 break;
2050 default:
2051 return -EINVAL;
2052 }
2053 switch (enabler->event_param.u.syscall.match) {
2054 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
2055 switch (enabler->format_type) {
2056 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2057 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2058 case LTTNG_ENABLER_FORMAT_NAME:
2059 return lttng_match_enabler_name(desc_name, enabler_name);
2060 default:
2061 return -EINVAL;
2062 }
2063 break;
2064 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
2065 return -EINVAL; /* Not implemented. */
2066 default:
2067 return -EINVAL;
2068 }
2069 break;
2070
2071 default:
2072 WARN_ON_ONCE(1);
2073 return -EINVAL;
2074 }
2075 }
2076
2077 static
2078 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
2079 struct lttng_kernel_event_recorder *event_recorder)
2080 {
2081 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
2082 event_enabler);
2083
2084 if (base_enabler->event_param.instrumentation != event_recorder->priv->parent.instrumentation)
2085 return 0;
2086 if (lttng_desc_match_enabler(event_recorder->priv->parent.desc, base_enabler)
2087 && event_recorder->chan == event_enabler->chan)
2088 return 1;
2089 else
2090 return 0;
2091 }
2092
2093 static
2094 int lttng_event_notifier_enabler_match_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler,
2095 struct lttng_kernel_event_notifier *event_notifier)
2096 {
2097 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(
2098 event_notifier_enabler);
2099
2100 if (base_enabler->event_param.instrumentation != event_notifier->priv->parent.instrumentation)
2101 return 0;
2102 if (lttng_desc_match_enabler(event_notifier->priv->parent.desc, base_enabler)
2103 && event_notifier->priv->group == event_notifier_enabler->group
2104 && event_notifier->priv->parent.user_token == event_notifier_enabler->base.user_token)
2105 return 1;
2106 else
2107 return 0;
2108 }
2109
2110 static
2111 struct lttng_enabler_ref *lttng_enabler_ref(
2112 struct list_head *enablers_ref_list,
2113 struct lttng_enabler *enabler)
2114 {
2115 struct lttng_enabler_ref *enabler_ref;
2116
2117 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2118 if (enabler_ref->ref == enabler)
2119 return enabler_ref;
2120 }
2121 return NULL;
2122 }
2123
2124 static
2125 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
2126 {
2127 struct lttng_kernel_session *session = event_enabler->chan->parent.session;
2128 struct lttng_kernel_probe_desc *probe_desc;
2129 const struct lttng_kernel_event_desc *desc;
2130 int i;
2131 struct list_head *probe_list;
2132
2133 probe_list = lttng_get_probe_list_head();
2134 /*
2135 * For each probe event, if we find that a probe event matches
2136 * our enabler, create an associated lttng_event if not
2137 * already present.
2138 */
2139 list_for_each_entry(probe_desc, probe_list, head) {
2140 for (i = 0; i < probe_desc->nr_events; i++) {
2141 int found = 0;
2142 struct hlist_head *head;
2143 struct lttng_kernel_event_recorder_private *event_recorder_private;
2144 struct lttng_kernel_event_recorder *event_recorder;
2145
2146 desc = probe_desc->event_desc[i];
2147 if (!lttng_desc_match_enabler(desc,
2148 lttng_event_enabler_as_enabler(event_enabler)))
2149 continue;
2150
2151 /*
2152 * Check if already created.
2153 */
2154 head = utils_borrow_hash_table_bucket(
2155 session->priv->events_ht.table, LTTNG_EVENT_HT_SIZE,
2156 desc->event_name);
2157 lttng_hlist_for_each_entry(event_recorder_private, head, hlist) {
2158 if (event_recorder_private->parent.desc == desc
2159 && event_recorder_private->pub->chan == event_enabler->chan)
2160 found = 1;
2161 }
2162 if (found)
2163 continue;
2164
2165 /*
2166 * We need to create an event for this
2167 * event probe.
2168 */
2169 event_recorder = _lttng_kernel_event_recorder_create(event_enabler->chan,
2170 NULL, desc, LTTNG_KERNEL_ABI_TRACEPOINT);
2171 if (!event_recorder) {
2172 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2173 probe_desc->event_desc[i]->event_name);
2174 }
2175 }
2176 }
2177 }
2178
2179 static
2180 void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2181 {
2182 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2183 struct lttng_kernel_probe_desc *probe_desc;
2184 const struct lttng_kernel_event_desc *desc;
2185 int i;
2186 struct list_head *probe_list;
2187
2188 probe_list = lttng_get_probe_list_head();
2189 /*
2190 * For each probe event, if we find that a probe event matches
2191 * our enabler, create an associated lttng_event_notifier if not
2192 * already present.
2193 */
2194 list_for_each_entry(probe_desc, probe_list, head) {
2195 for (i = 0; i < probe_desc->nr_events; i++) {
2196 int found = 0;
2197 struct hlist_head *head;
2198 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2199 struct lttng_kernel_event_notifier *event_notifier;
2200
2201 desc = probe_desc->event_desc[i];
2202 if (!lttng_desc_match_enabler(desc,
2203 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
2204 continue;
2205
2206 /*
2207 * Check if already created.
2208 */
2209 head = utils_borrow_hash_table_bucket(
2210 event_notifier_group->event_notifiers_ht.table,
2211 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->event_name);
2212 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
2213 if (event_notifier_priv->parent.desc == desc
2214 && event_notifier_priv->parent.user_token == event_notifier_enabler->base.user_token)
2215 found = 1;
2216 }
2217 if (found)
2218 continue;
2219
2220 /*
2221 * We need to create a event_notifier for this event probe.
2222 */
2223 event_notifier = _lttng_event_notifier_create(desc,
2224 event_notifier_enabler->base.user_token,
2225 event_notifier_enabler->error_counter_index,
2226 event_notifier_group, NULL,
2227 LTTNG_KERNEL_ABI_TRACEPOINT);
2228 if (IS_ERR(event_notifier)) {
2229 printk(KERN_INFO "Unable to create event_notifier %s\n",
2230 probe_desc->event_desc[i]->event_name);
2231 }
2232 }
2233 }
2234 }
2235
2236 static
2237 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
2238 {
2239 int ret;
2240
2241 ret = lttng_syscalls_register_event(event_enabler);
2242 WARN_ON_ONCE(ret);
2243 }
2244
2245 static
2246 void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2247 {
2248 int ret;
2249
2250 ret = lttng_syscalls_register_event_notifier(event_notifier_enabler);
2251 WARN_ON_ONCE(ret);
2252 ret = lttng_syscalls_create_matching_event_notifiers(event_notifier_enabler);
2253 WARN_ON_ONCE(ret);
2254 }
2255
2256 /*
2257 * Create struct lttng_kernel_event_recorder if it is missing and present in the list of
2258 * tracepoint probes.
2259 * Should be called with sessions mutex held.
2260 */
2261 static
2262 void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
2263 {
2264 switch (event_enabler->base.event_param.instrumentation) {
2265 case LTTNG_KERNEL_ABI_TRACEPOINT:
2266 lttng_create_tracepoint_event_if_missing(event_enabler);
2267 break;
2268
2269 case LTTNG_KERNEL_ABI_SYSCALL:
2270 lttng_create_syscall_event_if_missing(event_enabler);
2271 break;
2272
2273 default:
2274 WARN_ON_ONCE(1);
2275 break;
2276 }
2277 }
2278
2279 /*
2280 * Create events associated with an event_enabler (if not already present),
2281 * and add backward reference from the event to the enabler.
2282 * Should be called with sessions mutex held.
2283 */
2284 static
2285 int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
2286 {
2287 struct lttng_kernel_channel_buffer *chan = event_enabler->chan;
2288 struct lttng_kernel_session *session = event_enabler->chan->parent.session;
2289 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
2290 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2291
2292 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2293 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2294 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2295 !strcmp(base_enabler->event_param.name, "*")) {
2296 int enabled = base_enabler->enabled;
2297 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2298
2299 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2300 WRITE_ONCE(chan->priv->parent.syscall_all_entry, enabled);
2301
2302 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2303 WRITE_ONCE(chan->priv->parent.syscall_all_exit, enabled);
2304 }
2305
2306 /* First ensure that probe events are created for this enabler. */
2307 lttng_create_event_if_missing(event_enabler);
2308
2309 /* For each event matching event_enabler in session event list. */
2310 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
2311 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2312 struct lttng_enabler_ref *enabler_ref;
2313
2314 if (!lttng_event_enabler_match_event(event_enabler, event_recorder))
2315 continue;
2316 enabler_ref = lttng_enabler_ref(&event_recorder_priv->parent.enablers_ref_head,
2317 lttng_event_enabler_as_enabler(event_enabler));
2318 if (!enabler_ref) {
2319 /*
2320 * If no backward ref, create it.
2321 * Add backward ref from event to event_enabler.
2322 */
2323 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2324 if (!enabler_ref)
2325 return -ENOMEM;
2326 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
2327 list_add(&enabler_ref->node,
2328 &event_recorder_priv->parent.enablers_ref_head);
2329 }
2330
2331 /*
2332 * Link filter bytecodes if not linked yet.
2333 */
2334 lttng_enabler_link_bytecode(event_recorder_priv->parent.desc,
2335 lttng_static_ctx,
2336 &event_recorder_priv->parent.filter_bytecode_runtime_head,
2337 &lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
2338 }
2339 return 0;
2340 }
2341
2342 /*
2343 * Create struct lttng_kernel_event_notifier if it is missing and present in the list of
2344 * tracepoint probes.
2345 * Should be called with sessions mutex held.
2346 */
2347 static
2348 void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2349 {
2350 switch (event_notifier_enabler->base.event_param.instrumentation) {
2351 case LTTNG_KERNEL_ABI_TRACEPOINT:
2352 lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
2353 break;
2354
2355 case LTTNG_KERNEL_ABI_SYSCALL:
2356 lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler);
2357 break;
2358
2359 default:
2360 WARN_ON_ONCE(1);
2361 break;
2362 }
2363 }
2364
2365 /*
2366 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2367 */
2368 static
2369 int lttng_event_notifier_enabler_ref_event_notifiers(
2370 struct lttng_event_notifier_enabler *event_notifier_enabler)
2371 {
2372 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2373 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2374 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2375
2376 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2377 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2378 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2379 !strcmp(base_enabler->event_param.name, "*")) {
2380
2381 int enabled = base_enabler->enabled;
2382 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2383
2384 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2385 WRITE_ONCE(event_notifier_group->syscall_all_entry, enabled);
2386
2387 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2388 WRITE_ONCE(event_notifier_group->syscall_all_exit, enabled);
2389
2390 }
2391
2392 /* First ensure that probe event_notifiers are created for this enabler. */
2393 lttng_create_event_notifier_if_missing(event_notifier_enabler);
2394
2395 /* Link the created event_notifier with its associated enabler. */
2396 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2397 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2398 struct lttng_enabler_ref *enabler_ref;
2399
2400 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier))
2401 continue;
2402
2403 enabler_ref = lttng_enabler_ref(&event_notifier_priv->parent.enablers_ref_head,
2404 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2405 if (!enabler_ref) {
2406 /*
2407 * If no backward ref, create it.
2408 * Add backward ref from event_notifier to enabler.
2409 */
2410 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2411 if (!enabler_ref)
2412 return -ENOMEM;
2413
2414 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2415 event_notifier_enabler);
2416 list_add(&enabler_ref->node,
2417 &event_notifier_priv->parent.enablers_ref_head);
2418 }
2419
2420 /*
2421 * Link filter bytecodes if not linked yet.
2422 */
2423 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2424 lttng_static_ctx, &event_notifier_priv->parent.filter_bytecode_runtime_head,
2425 &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
2426
2427 /* Link capture bytecodes if not linked yet. */
2428 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2429 lttng_static_ctx, &event_notifier_priv->capture_bytecode_runtime_head,
2430 &event_notifier_enabler->capture_bytecode_head);
2431
2432 event_notifier_priv->num_captures = event_notifier_enabler->num_captures;
2433 }
2434 return 0;
2435 }
2436
2437 /*
2438 * Called at module load: connect the probe on all enablers matching
2439 * this event.
2440 * Called with sessions lock held.
2441 */
2442 int lttng_fix_pending_events(void)
2443 {
2444 struct lttng_kernel_session_private *session_priv;
2445
2446 list_for_each_entry(session_priv, &sessions, list)
2447 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2448 return 0;
2449 }
2450
2451 static bool lttng_event_notifier_group_has_active_event_notifiers(
2452 struct lttng_event_notifier_group *event_notifier_group)
2453 {
2454 struct lttng_event_notifier_enabler *event_notifier_enabler;
2455
2456 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2457 node) {
2458 if (event_notifier_enabler->base.enabled)
2459 return true;
2460 }
2461 return false;
2462 }
2463
2464 bool lttng_event_notifier_active(void)
2465 {
2466 struct lttng_event_notifier_group *event_notifier_group;
2467
2468 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2469 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2470 return true;
2471 }
2472 return false;
2473 }
2474
2475 int lttng_fix_pending_event_notifiers(void)
2476 {
2477 struct lttng_event_notifier_group *event_notifier_group;
2478
2479 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2480 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2481 return 0;
2482 }
2483
2484 struct lttng_event_enabler *lttng_event_enabler_create(
2485 enum lttng_enabler_format_type format_type,
2486 struct lttng_kernel_abi_event *event_param,
2487 struct lttng_kernel_channel_buffer *chan)
2488 {
2489 struct lttng_event_enabler *event_enabler;
2490
2491 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2492 if (!event_enabler)
2493 return NULL;
2494 event_enabler->base.format_type = format_type;
2495 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2496 memcpy(&event_enabler->base.event_param, event_param,
2497 sizeof(event_enabler->base.event_param));
2498 event_enabler->chan = chan;
2499 /* ctx left NULL */
2500 event_enabler->base.enabled = 0;
2501 mutex_lock(&sessions_mutex);
2502 list_add(&event_enabler->node, &event_enabler->chan->parent.session->priv->enablers_head);
2503 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2504 mutex_unlock(&sessions_mutex);
2505 return event_enabler;
2506 }
2507
2508 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2509 {
2510 mutex_lock(&sessions_mutex);
2511 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2512 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2513 mutex_unlock(&sessions_mutex);
2514 return 0;
2515 }
2516
2517 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2518 {
2519 mutex_lock(&sessions_mutex);
2520 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2521 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2522 mutex_unlock(&sessions_mutex);
2523 return 0;
2524 }
2525
2526 static
2527 int lttng_enabler_attach_filter_bytecode(struct lttng_enabler *enabler,
2528 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2529 {
2530 struct lttng_kernel_bytecode_node *bytecode_node;
2531 uint32_t bytecode_len;
2532 int ret;
2533
2534 ret = get_user(bytecode_len, &bytecode->len);
2535 if (ret)
2536 return ret;
2537 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2538 GFP_KERNEL);
2539 if (!bytecode_node)
2540 return -ENOMEM;
2541 ret = copy_from_user(&bytecode_node->bc, bytecode,
2542 sizeof(*bytecode) + bytecode_len);
2543 if (ret)
2544 goto error_free;
2545
2546 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2547 bytecode_node->enabler = enabler;
2548 /* Enforce length based on allocated size */
2549 bytecode_node->bc.len = bytecode_len;
2550 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2551
2552 return 0;
2553
2554 error_free:
2555 lttng_kvfree(bytecode_node);
2556 return ret;
2557 }
2558
2559 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler *event_enabler,
2560 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2561 {
2562 int ret;
2563 ret = lttng_enabler_attach_filter_bytecode(
2564 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2565 if (ret)
2566 goto error;
2567
2568 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2569 return 0;
2570
2571 error:
2572 return ret;
2573 }
2574
2575 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2576 struct lttng_kernel_abi_event_callsite __user *callsite)
2577 {
2578
2579 switch (event->priv->instrumentation) {
2580 case LTTNG_KERNEL_ABI_UPROBE:
2581 return lttng_uprobes_event_add_callsite(event, callsite);
2582 default:
2583 return -EINVAL;
2584 }
2585 }
2586
2587 static
2588 void lttng_enabler_destroy(struct lttng_enabler *enabler)
2589 {
2590 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2591
2592 /* Destroy filter bytecode */
2593 list_for_each_entry_safe(filter_node, tmp_filter_node,
2594 &enabler->filter_bytecode_head, node) {
2595 lttng_kvfree(filter_node);
2596 }
2597 }
2598
2599 static
2600 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2601 {
2602 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2603
2604 list_del(&event_enabler->node);
2605 kfree(event_enabler);
2606 }
2607
2608 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2609 struct lttng_event_notifier_group *event_notifier_group,
2610 enum lttng_enabler_format_type format_type,
2611 struct lttng_kernel_abi_event_notifier *event_notifier_param)
2612 {
2613 struct lttng_event_notifier_enabler *event_notifier_enabler;
2614
2615 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2616 if (!event_notifier_enabler)
2617 return NULL;
2618
2619 event_notifier_enabler->base.format_type = format_type;
2620 INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
2621 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2622
2623 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2624 event_notifier_enabler->num_captures = 0;
2625
2626 memcpy(&event_notifier_enabler->base.event_param, &event_notifier_param->event,
2627 sizeof(event_notifier_enabler->base.event_param));
2628
2629 event_notifier_enabler->base.enabled = 0;
2630 event_notifier_enabler->base.user_token = event_notifier_param->event.token;
2631 event_notifier_enabler->group = event_notifier_group;
2632
2633 mutex_lock(&sessions_mutex);
2634 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2635 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2636
2637 mutex_unlock(&sessions_mutex);
2638
2639 return event_notifier_enabler;
2640 }
2641
2642 int lttng_event_notifier_enabler_enable(
2643 struct lttng_event_notifier_enabler *event_notifier_enabler)
2644 {
2645 mutex_lock(&sessions_mutex);
2646 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2647 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2648 mutex_unlock(&sessions_mutex);
2649 return 0;
2650 }
2651
2652 int lttng_event_notifier_enabler_disable(
2653 struct lttng_event_notifier_enabler *event_notifier_enabler)
2654 {
2655 mutex_lock(&sessions_mutex);
2656 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2657 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2658 mutex_unlock(&sessions_mutex);
2659 return 0;
2660 }
2661
2662 int lttng_event_notifier_enabler_attach_filter_bytecode(
2663 struct lttng_event_notifier_enabler *event_notifier_enabler,
2664 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2665 {
2666 int ret;
2667
2668 ret = lttng_enabler_attach_filter_bytecode(
2669 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
2670 bytecode);
2671 if (ret)
2672 goto error;
2673
2674 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2675 return 0;
2676
2677 error:
2678 return ret;
2679 }
2680
2681 int lttng_event_notifier_enabler_attach_capture_bytecode(
2682 struct lttng_event_notifier_enabler *event_notifier_enabler,
2683 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2684 {
2685 struct lttng_kernel_bytecode_node *bytecode_node;
2686 struct lttng_enabler *enabler =
2687 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2688 uint32_t bytecode_len;
2689 int ret;
2690
2691 ret = get_user(bytecode_len, &bytecode->len);
2692 if (ret)
2693 return ret;
2694
2695 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2696 GFP_KERNEL);
2697 if (!bytecode_node)
2698 return -ENOMEM;
2699
2700 ret = copy_from_user(&bytecode_node->bc, bytecode,
2701 sizeof(*bytecode) + bytecode_len);
2702 if (ret)
2703 goto error_free;
2704
2705 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2706 bytecode_node->enabler = enabler;
2707
2708 /* Enforce length based on allocated size */
2709 bytecode_node->bc.len = bytecode_len;
2710 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2711
2712 event_notifier_enabler->num_captures++;
2713
2714 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2715 goto end;
2716
2717 error_free:
2718 lttng_kvfree(bytecode_node);
2719 end:
2720 return ret;
2721 }
2722
2723 static
2724 void lttng_event_notifier_enabler_destroy(
2725 struct lttng_event_notifier_enabler *event_notifier_enabler)
2726 {
2727 if (!event_notifier_enabler) {
2728 return;
2729 }
2730
2731 list_del(&event_notifier_enabler->node);
2732
2733 lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2734 kfree(event_notifier_enabler);
2735 }
2736
2737 /*
2738 * lttng_session_sync_event_enablers should be called just before starting a
2739 * session.
2740 * Should be called with sessions mutex held.
2741 */
2742 static
2743 void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2744 {
2745 struct lttng_event_enabler *event_enabler;
2746 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2747
2748 list_for_each_entry(event_enabler, &session->priv->enablers_head, node)
2749 lttng_event_enabler_ref_events(event_enabler);
2750 /*
2751 * For each event, if at least one of its enablers is enabled,
2752 * and its channel and session transient states are enabled, we
2753 * enable the event, else we disable it.
2754 */
2755 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
2756 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2757 struct lttng_enabler_ref *enabler_ref;
2758 struct lttng_kernel_bytecode_runtime *runtime;
2759 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2760 int nr_filters = 0;
2761
2762 switch (event_recorder_priv->parent.instrumentation) {
2763 case LTTNG_KERNEL_ABI_TRACEPOINT:
2764 lttng_fallthrough;
2765 case LTTNG_KERNEL_ABI_SYSCALL:
2766 /* Enable events */
2767 list_for_each_entry(enabler_ref,
2768 &event_recorder_priv->parent.enablers_ref_head, node) {
2769 if (enabler_ref->ref->enabled) {
2770 enabled = 1;
2771 break;
2772 }
2773 }
2774 break;
2775
2776 default:
2777 /* Not handled with lazy sync. */
2778 continue;
2779 }
2780 /*
2781 * Enabled state is based on union of enablers, with
2782 * intesection of session and channel transient enable
2783 * states.
2784 */
2785 enabled = enabled && session->priv->tstate && event_recorder->chan->priv->parent.tstate;
2786
2787 WRITE_ONCE(event_recorder->parent.enabled, enabled);
2788 /*
2789 * Sync tracepoint registration with event enabled
2790 * state.
2791 */
2792 if (enabled) {
2793 if (!event_recorder_priv->parent.registered)
2794 register_event(event_recorder);
2795 } else {
2796 if (event_recorder_priv->parent.registered)
2797 _lttng_event_unregister(event_recorder);
2798 }
2799
2800 /* Check if has enablers without bytecode enabled */
2801 list_for_each_entry(enabler_ref,
2802 &event_recorder_priv->parent.enablers_ref_head, node) {
2803 if (enabler_ref->ref->enabled
2804 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2805 has_enablers_without_filter_bytecode = 1;
2806 break;
2807 }
2808 }
2809 event_recorder_priv->parent.has_enablers_without_filter_bytecode =
2810 has_enablers_without_filter_bytecode;
2811
2812 /* Enable filters */
2813 list_for_each_entry(runtime,
2814 &event_recorder_priv->parent.filter_bytecode_runtime_head, node) {
2815 lttng_bytecode_sync_state(runtime);
2816 nr_filters++;
2817 }
2818 WRITE_ONCE(event_recorder_priv->parent.pub->eval_filter,
2819 !(has_enablers_without_filter_bytecode || !nr_filters));
2820 }
2821 }
2822
2823 /*
2824 * Apply enablers to session events, adding events to session if need
2825 * be. It is required after each modification applied to an active
2826 * session, and right before session "start".
2827 * "lazy" sync means we only sync if required.
2828 * Should be called with sessions mutex held.
2829 */
2830 static
2831 void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2832 {
2833 /* We can skip if session is not active */
2834 if (!session->active)
2835 return;
2836 lttng_session_sync_event_enablers(session);
2837 }
2838
2839 static
2840 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2841 {
2842 struct lttng_event_notifier_enabler *event_notifier_enabler;
2843 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2844
2845 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2846 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2847
2848 /*
2849 * For each event_notifier, if at least one of its enablers is enabled,
2850 * we enable the event_notifier, else we disable it.
2851 */
2852 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2853 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2854 struct lttng_enabler_ref *enabler_ref;
2855 struct lttng_kernel_bytecode_runtime *runtime;
2856 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2857 int nr_filters = 0, nr_captures = 0;
2858
2859 switch (event_notifier_priv->parent.instrumentation) {
2860 case LTTNG_KERNEL_ABI_TRACEPOINT:
2861 lttng_fallthrough;
2862 case LTTNG_KERNEL_ABI_SYSCALL:
2863 /* Enable event_notifiers */
2864 list_for_each_entry(enabler_ref,
2865 &event_notifier_priv->parent.enablers_ref_head, node) {
2866 if (enabler_ref->ref->enabled) {
2867 enabled = 1;
2868 break;
2869 }
2870 }
2871 break;
2872
2873 default:
2874 /* Not handled with sync. */
2875 continue;
2876 }
2877
2878 WRITE_ONCE(event_notifier->parent.enabled, enabled);
2879 /*
2880 * Sync tracepoint registration with event_notifier enabled
2881 * state.
2882 */
2883 if (enabled) {
2884 if (!event_notifier_priv->parent.registered)
2885 register_event_notifier(event_notifier);
2886 } else {
2887 if (event_notifier_priv->parent.registered)
2888 unregister_event_notifier(event_notifier);
2889 }
2890
2891 /* Check if has enablers without bytecode enabled */
2892 list_for_each_entry(enabler_ref,
2893 &event_notifier_priv->parent.enablers_ref_head, node) {
2894 if (enabler_ref->ref->enabled
2895 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2896 has_enablers_without_filter_bytecode = 1;
2897 break;
2898 }
2899 }
2900 event_notifier_priv->parent.has_enablers_without_filter_bytecode =
2901 has_enablers_without_filter_bytecode;
2902
2903 /* Enable filters */
2904 list_for_each_entry(runtime,
2905 &event_notifier_priv->parent.filter_bytecode_runtime_head, node) {
2906 lttng_bytecode_sync_state(runtime);
2907 nr_filters++;
2908 }
2909 WRITE_ONCE(event_notifier_priv->parent.pub->eval_filter,
2910 !(has_enablers_without_filter_bytecode || !nr_filters));
2911
2912 /* Enable captures */
2913 list_for_each_entry(runtime,
2914 &event_notifier_priv->capture_bytecode_runtime_head, node) {
2915 lttng_bytecode_sync_state(runtime);
2916 nr_captures++;
2917 }
2918 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2919 }
2920 }
2921
2922 /*
2923 * Serialize at most one packet worth of metadata into a metadata
2924 * channel.
2925 * We grab the metadata cache mutex to get exclusive access to our metadata
2926 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2927 * allows us to do racy operations such as looking for remaining space left in
2928 * packet and write, since mutual exclusion protects us from concurrent writes.
2929 * Mutual exclusion on the metadata cache allow us to read the cache content
2930 * without racing against reallocation of the cache by updates.
2931 * Returns the number of bytes written in the channel, 0 if no data
2932 * was written and a negative value on error.
2933 */
2934 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2935 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2936 {
2937 struct lttng_kernel_ring_buffer_ctx ctx;
2938 int ret = 0;
2939 size_t len, reserve_len;
2940
2941 /*
2942 * Ensure we support mutiple get_next / put sequences followed by
2943 * put_next. The metadata cache lock protects reading the metadata
2944 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2945 * "flush" operations on the buffer invoked by different processes.
2946 * Moreover, since the metadata cache memory can be reallocated, we
2947 * need to have exclusive access against updates even though we only
2948 * read it.
2949 */
2950 mutex_lock(&stream->metadata_cache->lock);
2951 WARN_ON(stream->metadata_in < stream->metadata_out);
2952 if (stream->metadata_in != stream->metadata_out)
2953 goto end;
2954
2955 /* Metadata regenerated, change the version. */
2956 if (stream->metadata_cache->version != stream->version)
2957 stream->version = stream->metadata_cache->version;
2958
2959 len = stream->metadata_cache->metadata_written -
2960 stream->metadata_in;
2961 if (!len)
2962 goto end;
2963 reserve_len = min_t(size_t,
2964 stream->transport->ops.priv->packet_avail_size(chan),
2965 len);
2966 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2967 sizeof(char), NULL);
2968 /*
2969 * If reservation failed, return an error to the caller.
2970 */
2971 ret = stream->transport->ops.event_reserve(&ctx);
2972 if (ret != 0) {
2973 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2974 stream->coherent = false;
2975 goto end;
2976 }
2977 stream->transport->ops.event_write(&ctx,
2978 stream->metadata_cache->data + stream->metadata_in,
2979 reserve_len, 1);
2980 stream->transport->ops.event_commit(&ctx);
2981 stream->metadata_in += reserve_len;
2982 if (reserve_len < len)
2983 stream->coherent = false;
2984 else
2985 stream->coherent = true;
2986 ret = reserve_len;
2987
2988 end:
2989 if (coherent)
2990 *coherent = stream->coherent;
2991 mutex_unlock(&stream->metadata_cache->lock);
2992 return ret;
2993 }
2994
2995 static
2996 void lttng_metadata_begin(struct lttng_kernel_session *session)
2997 {
2998 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
2999 mutex_lock(&session->priv->metadata_cache->lock);
3000 }
3001
3002 static
3003 void lttng_metadata_end(struct lttng_kernel_session *session)
3004 {
3005 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
3006 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
3007 struct lttng_metadata_stream *stream;
3008
3009 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
3010 wake_up_interruptible(&stream->read_wait);
3011 mutex_unlock(&session->priv->metadata_cache->lock);
3012 }
3013 }
3014
3015 /*
3016 * Write the metadata to the metadata cache.
3017 * Must be called with sessions_mutex held.
3018 * The metadata cache lock protects us from concurrent read access from
3019 * thread outputting metadata content to ring buffer.
3020 * The content of the printf is printed as a single atomic metadata
3021 * transaction.
3022 */
3023 int lttng_metadata_printf(struct lttng_kernel_session *session,
3024 const char *fmt, ...)
3025 {
3026 char *str;
3027 size_t len;
3028 va_list ap;
3029
3030 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
3031
3032 va_start(ap, fmt);
3033 str = kvasprintf(GFP_KERNEL, fmt, ap);
3034 va_end(ap);
3035 if (!str)
3036 return -ENOMEM;
3037
3038 len = strlen(str);
3039 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
3040 if (session->priv->metadata_cache->metadata_written + len >
3041 session->priv->metadata_cache->cache_alloc) {
3042 char *tmp_cache_realloc;
3043 unsigned int tmp_cache_alloc_size;
3044
3045 tmp_cache_alloc_size = max_t(unsigned int,
3046 session->priv->metadata_cache->cache_alloc + len,
3047 session->priv->metadata_cache->cache_alloc << 1);
3048 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
3049 if (!tmp_cache_realloc)
3050 goto err;
3051 if (session->priv->metadata_cache->data) {
3052 memcpy(tmp_cache_realloc,
3053 session->priv->metadata_cache->data,
3054 session->priv->metadata_cache->cache_alloc);
3055 vfree(session->priv->metadata_cache->data);
3056 }
3057
3058 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
3059 session->priv->metadata_cache->data = tmp_cache_realloc;
3060 }
3061 memcpy(session->priv->metadata_cache->data +
3062 session->priv->metadata_cache->metadata_written,
3063 str, len);
3064 session->priv->metadata_cache->metadata_written += len;
3065 kfree(str);
3066
3067 return 0;
3068
3069 err:
3070 kfree(str);
3071 return -ENOMEM;
3072 }
3073
3074 static
3075 int print_tabs(struct lttng_kernel_session *session, size_t nesting)
3076 {
3077 size_t i;
3078
3079 for (i = 0; i < nesting; i++) {
3080 int ret;
3081
3082 ret = lttng_metadata_printf(session, " ");
3083 if (ret) {
3084 return ret;
3085 }
3086 }
3087 return 0;
3088 }
3089
3090 static
3091 int lttng_field_name_statedump(struct lttng_kernel_session *session,
3092 const struct lttng_kernel_event_field *field,
3093 size_t nesting)
3094 {
3095 return lttng_metadata_printf(session, " _%s;\n", field->name);
3096 }
3097
3098 static
3099 int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
3100 const struct lttng_kernel_type_integer *type,
3101 enum lttng_kernel_string_encoding parent_encoding,
3102 size_t nesting)
3103 {
3104 int ret;
3105
3106 ret = print_tabs(session, nesting);
3107 if (ret)
3108 return ret;
3109 ret = lttng_metadata_printf(session,
3110 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
3111 type->size,
3112 type->alignment,
3113 type->signedness,
3114 (parent_encoding == lttng_kernel_string_encoding_none)
3115 ? "none"
3116 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
3117 ? "UTF8"
3118 : "ASCII",
3119 type->base,
3120 #if __BYTE_ORDER == __BIG_ENDIAN
3121 type->reverse_byte_order ? " byte_order = le;" : ""
3122 #else
3123 type->reverse_byte_order ? " byte_order = be;" : ""
3124 #endif
3125 );
3126 return ret;
3127 }
3128
3129 /*
3130 * Must be called with sessions_mutex held.
3131 */
3132 static
3133 int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
3134 const struct lttng_kernel_type_struct *type,
3135 size_t nesting)
3136 {
3137 const char *prev_field_name = NULL;
3138 int ret;
3139 uint32_t i, nr_fields;
3140 unsigned int alignment;
3141
3142 ret = print_tabs(session, nesting);
3143 if (ret)
3144 return ret;
3145 ret = lttng_metadata_printf(session,
3146 "struct {\n");
3147 if (ret)
3148 return ret;
3149 nr_fields = type->nr_fields;
3150 for (i = 0; i < nr_fields; i++) {
3151 const struct lttng_kernel_event_field *iter_field;
3152
3153 iter_field = type->fields[i];
3154 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
3155 if (ret)
3156 return ret;
3157 }
3158 ret = print_tabs(session, nesting);
3159 if (ret)
3160 return ret;
3161 alignment = type->alignment;
3162 if (alignment) {
3163 ret = lttng_metadata_printf(session,
3164 "} align(%u)",
3165 alignment);
3166 } else {
3167 ret = lttng_metadata_printf(session,
3168 "}");
3169 }
3170 return ret;
3171 }
3172
3173 /*
3174 * Must be called with sessions_mutex held.
3175 */
3176 static
3177 int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
3178 const struct lttng_kernel_event_field *field,
3179 size_t nesting)
3180 {
3181 int ret;
3182
3183 ret = _lttng_struct_type_statedump(session,
3184 lttng_kernel_get_type_struct(field->type), nesting);
3185 if (ret)
3186 return ret;
3187 return lttng_field_name_statedump(session, field, nesting);
3188 }
3189
3190 /*
3191 * Must be called with sessions_mutex held.
3192 */
3193 static
3194 int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
3195 const struct lttng_kernel_type_variant *type,
3196 size_t nesting,
3197 const char *prev_field_name)
3198 {
3199 const char *tag_name;
3200 int ret;
3201 uint32_t i, nr_choices;
3202
3203 tag_name = type->tag_name;
3204 if (!tag_name)
3205 tag_name = prev_field_name;
3206 if (!tag_name)
3207 return -EINVAL;
3208 /*
3209 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3210 */
3211 if (type->alignment != 0)
3212 return -EINVAL;
3213 ret = print_tabs(session, nesting);
3214 if (ret)
3215 return ret;
3216 ret = lttng_metadata_printf(session,
3217 "variant <_%s> {\n",
3218 tag_name);
3219 if (ret)
3220 return ret;
3221 nr_choices = type->nr_choices;
3222 for (i = 0; i < nr_choices; i++) {
3223 const struct lttng_kernel_event_field *iter_field;
3224
3225 iter_field = type->choices[i];
3226 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3227 if (ret)
3228 return ret;
3229 }
3230 ret = print_tabs(session, nesting);
3231 if (ret)
3232 return ret;
3233 ret = lttng_metadata_printf(session,
3234 "}");
3235 return ret;
3236 }
3237
3238 /*
3239 * Must be called with sessions_mutex held.
3240 */
3241 static
3242 int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3243 const struct lttng_kernel_event_field *field,
3244 size_t nesting,
3245 const char *prev_field_name)
3246 {
3247 int ret;
3248
3249 ret = _lttng_variant_type_statedump(session,
3250 lttng_kernel_get_type_variant(field->type), nesting,
3251 prev_field_name);
3252 if (ret)
3253 return ret;
3254 return lttng_field_name_statedump(session, field, nesting);
3255 }
3256
3257 /*
3258 * Must be called with sessions_mutex held.
3259 */
3260 static
3261 int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3262 const struct lttng_kernel_event_field *field,
3263 size_t nesting)
3264 {
3265 int ret;
3266 const struct lttng_kernel_type_array *array_type;
3267 const struct lttng_kernel_type_common *elem_type;
3268
3269 array_type = lttng_kernel_get_type_array(field->type);
3270 WARN_ON_ONCE(!array_type);
3271
3272 if (array_type->alignment) {
3273 ret = print_tabs(session, nesting);
3274 if (ret)
3275 return ret;
3276 ret = lttng_metadata_printf(session,
3277 "struct { } align(%u) _%s_padding;\n",
3278 array_type->alignment * CHAR_BIT,
3279 field->name);
3280 if (ret)
3281 return ret;
3282 }
3283 /*
3284 * Nested compound types: Only array of structures and variants are
3285 * currently supported.
3286 */
3287 elem_type = array_type->elem_type;
3288 switch (elem_type->type) {
3289 case lttng_kernel_type_integer:
3290 case lttng_kernel_type_struct:
3291 case lttng_kernel_type_variant:
3292 ret = _lttng_type_statedump(session, elem_type,
3293 array_type->encoding, nesting);
3294 if (ret)
3295 return ret;
3296 break;
3297
3298 default:
3299 return -EINVAL;
3300 }
3301 ret = lttng_metadata_printf(session,
3302 " _%s[%u];\n",
3303 field->name,
3304 array_type->length);
3305 return ret;
3306 }
3307
3308 /*
3309 * Must be called with sessions_mutex held.
3310 */
3311 static
3312 int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3313 const struct lttng_kernel_event_field *field,
3314 size_t nesting,
3315 const char *prev_field_name)
3316 {
3317 int ret;
3318 const char *length_name;
3319 const struct lttng_kernel_type_sequence *sequence_type;
3320 const struct lttng_kernel_type_common *elem_type;
3321
3322 sequence_type = lttng_kernel_get_type_sequence(field->type);
3323 WARN_ON_ONCE(!sequence_type);
3324
3325 length_name = sequence_type->length_name;
3326 if (!length_name)
3327 length_name = prev_field_name;
3328 if (!length_name)
3329 return -EINVAL;
3330
3331 if (sequence_type->alignment) {
3332 ret = print_tabs(session, nesting);
3333 if (ret)
3334 return ret;
3335 ret = lttng_metadata_printf(session,
3336 "struct { } align(%u) _%s_padding;\n",
3337 sequence_type->alignment * CHAR_BIT,
3338 field->name);
3339 if (ret)
3340 return ret;
3341 }
3342
3343 /*
3344 * Nested compound types: Only array of structures and variants are
3345 * currently supported.
3346 */
3347 elem_type = sequence_type->elem_type;
3348 switch (elem_type->type) {
3349 case lttng_kernel_type_integer:
3350 case lttng_kernel_type_struct:
3351 case lttng_kernel_type_variant:
3352 ret = _lttng_type_statedump(session, elem_type,
3353 sequence_type->encoding, nesting);
3354 if (ret)
3355 return ret;
3356 break;
3357
3358 default:
3359 return -EINVAL;
3360 }
3361 ret = lttng_metadata_printf(session,
3362 " _%s[ _%s ];\n",
3363 field->name,
3364 length_name);
3365 return ret;
3366 }
3367
3368 /*
3369 * Must be called with sessions_mutex held.
3370 */
3371 static
3372 int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3373 const struct lttng_kernel_type_enum *type,
3374 size_t nesting)
3375 {
3376 const struct lttng_kernel_enum_desc *enum_desc;
3377 const struct lttng_kernel_type_common *container_type;
3378 int ret;
3379 unsigned int i, nr_entries;
3380
3381 container_type = type->container_type;
3382 if (container_type->type != lttng_kernel_type_integer) {
3383 ret = -EINVAL;
3384 goto end;
3385 }
3386 enum_desc = type->desc;
3387 nr_entries = enum_desc->nr_entries;
3388
3389 ret = print_tabs(session, nesting);
3390 if (ret)
3391 goto end;
3392 ret = lttng_metadata_printf(session, "enum : ");
3393 if (ret)
3394 goto end;
3395 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3396 lttng_kernel_string_encoding_none, 0);
3397 if (ret)
3398 goto end;
3399 ret = lttng_metadata_printf(session, " {\n");
3400 if (ret)
3401 goto end;
3402 /* Dump all entries */
3403 for (i = 0; i < nr_entries; i++) {
3404 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3405 int j, len;
3406
3407 ret = print_tabs(session, nesting + 1);
3408 if (ret)
3409 goto end;
3410 ret = lttng_metadata_printf(session,
3411 "\"");
3412 if (ret)
3413 goto end;
3414 len = strlen(entry->string);
3415 /* Escape the character '"' */
3416 for (j = 0; j < len; j++) {
3417 char c = entry->string[j];
3418
3419 switch (c) {
3420 case '"':
3421 ret = lttng_metadata_printf(session,
3422 "\\\"");
3423 break;
3424 case '\\':
3425 ret = lttng_metadata_printf(session,
3426 "\\\\");
3427 break;
3428 default:
3429 ret = lttng_metadata_printf(session,
3430 "%c", c);
3431 break;
3432 }
3433 if (ret)
3434 goto end;
3435 }
3436 ret = lttng_metadata_printf(session, "\"");
3437 if (ret)
3438 goto end;
3439
3440 if (entry->options.is_auto) {
3441 ret = lttng_metadata_printf(session, ",\n");
3442 if (ret)
3443 goto end;
3444 } else {
3445 ret = lttng_metadata_printf(session,
3446 " = ");
3447 if (ret)
3448 goto end;
3449 if (entry->start.signedness)
3450 ret = lttng_metadata_printf(session,
3451 "%lld", (long long) entry->start.value);
3452 else
3453 ret = lttng_metadata_printf(session,
3454 "%llu", entry->start.value);
3455 if (ret)
3456 goto end;
3457 if (entry->start.signedness == entry->end.signedness &&
3458 entry->start.value
3459 == entry->end.value) {
3460 ret = lttng_metadata_printf(session,
3461 ",\n");
3462 } else {
3463 if (entry->end.signedness) {
3464 ret = lttng_metadata_printf(session,
3465 " ... %lld,\n",
3466 (long long) entry->end.value);
3467 } else {
3468 ret = lttng_metadata_printf(session,
3469 " ... %llu,\n",
3470 entry->end.value);
3471 }
3472 }
3473 if (ret)
3474 goto end;
3475 }
3476 }
3477 ret = print_tabs(session, nesting);
3478 if (ret)
3479 goto end;
3480 ret = lttng_metadata_printf(session, "}");
3481 end:
3482 return ret;
3483 }
3484
3485 /*
3486 * Must be called with sessions_mutex held.
3487 */
3488 static
3489 int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3490 const struct lttng_kernel_event_field *field,
3491 size_t nesting)
3492 {
3493 int ret;
3494 const struct lttng_kernel_type_enum *enum_type;
3495
3496 enum_type = lttng_kernel_get_type_enum(field->type);
3497 WARN_ON_ONCE(!enum_type);
3498 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3499 if (ret)
3500 return ret;
3501 return lttng_field_name_statedump(session, field, nesting);
3502 }
3503
3504 static
3505 int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3506 const struct lttng_kernel_event_field *field,
3507 size_t nesting)
3508 {
3509 int ret;
3510
3511 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3512 lttng_kernel_string_encoding_none, nesting);
3513 if (ret)
3514 return ret;
3515 return lttng_field_name_statedump(session, field, nesting);
3516 }
3517
3518 static
3519 int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3520 const struct lttng_kernel_type_string *type,
3521 size_t nesting)
3522 {
3523 int ret;
3524
3525 /* Default encoding is UTF8 */
3526 ret = print_tabs(session, nesting);
3527 if (ret)
3528 return ret;
3529 ret = lttng_metadata_printf(session,
3530 "string%s",
3531 type->encoding == lttng_kernel_string_encoding_ASCII ?
3532 " { encoding = ASCII; }" : "");
3533 return ret;
3534 }
3535
3536 static
3537 int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3538 const struct lttng_kernel_event_field *field,
3539 size_t nesting)
3540 {
3541 const struct lttng_kernel_type_string *string_type;
3542 int ret;
3543
3544 string_type = lttng_kernel_get_type_string(field->type);
3545 WARN_ON_ONCE(!string_type);
3546 ret = _lttng_string_type_statedump(session, string_type, nesting);
3547 if (ret)
3548 return ret;
3549 return lttng_field_name_statedump(session, field, nesting);
3550 }
3551
3552 /*
3553 * Must be called with sessions_mutex held.
3554 */
3555 static
3556 int _lttng_type_statedump(struct lttng_kernel_session *session,
3557 const struct lttng_kernel_type_common *type,
3558 enum lttng_kernel_string_encoding parent_encoding,
3559 size_t nesting)
3560 {
3561 int ret = 0;
3562
3563 switch (type->type) {
3564 case lttng_kernel_type_integer:
3565 ret = _lttng_integer_type_statedump(session,
3566 lttng_kernel_get_type_integer(type),
3567 parent_encoding, nesting);
3568 break;
3569 case lttng_kernel_type_enum:
3570 ret = _lttng_enum_type_statedump(session,
3571 lttng_kernel_get_type_enum(type),
3572 nesting);
3573 break;
3574 case lttng_kernel_type_string:
3575 ret = _lttng_string_type_statedump(session,
3576 lttng_kernel_get_type_string(type),
3577 nesting);
3578 break;
3579 case lttng_kernel_type_struct:
3580 ret = _lttng_struct_type_statedump(session,
3581 lttng_kernel_get_type_struct(type),
3582 nesting);
3583 break;
3584 case lttng_kernel_type_variant:
3585 ret = _lttng_variant_type_statedump(session,
3586 lttng_kernel_get_type_variant(type),
3587 nesting, NULL);
3588 break;
3589
3590 /* Nested arrays and sequences are not supported yet. */
3591 case lttng_kernel_type_array:
3592 case lttng_kernel_type_sequence:
3593 default:
3594 WARN_ON_ONCE(1);
3595 return -EINVAL;
3596 }
3597 return ret;
3598 }
3599
3600 /*
3601 * Must be called with sessions_mutex held.
3602 */
3603 static
3604 int _lttng_field_statedump(struct lttng_kernel_session *session,
3605 const struct lttng_kernel_event_field *field,
3606 size_t nesting,
3607 const char **prev_field_name_p)
3608 {
3609 const char *prev_field_name = NULL;
3610 int ret = 0;
3611
3612 if (prev_field_name_p)
3613 prev_field_name = *prev_field_name_p;
3614 switch (field->type->type) {
3615 case lttng_kernel_type_integer:
3616 ret = _lttng_integer_field_statedump(session, field, nesting);
3617 break;
3618 case lttng_kernel_type_enum:
3619 ret = _lttng_enum_field_statedump(session, field, nesting);
3620 break;
3621 case lttng_kernel_type_string:
3622 ret = _lttng_string_field_statedump(session, field, nesting);
3623 break;
3624 case lttng_kernel_type_struct:
3625 ret = _lttng_struct_field_statedump(session, field, nesting);
3626 break;
3627 case lttng_kernel_type_array:
3628 ret = _lttng_array_field_statedump(session, field, nesting);
3629 break;
3630 case lttng_kernel_type_sequence:
3631 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3632 break;
3633 case lttng_kernel_type_variant:
3634 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3635 break;
3636
3637 default:
3638 WARN_ON_ONCE(1);
3639 return -EINVAL;
3640 }
3641 if (prev_field_name_p)
3642 *prev_field_name_p = field->name;
3643 return ret;
3644 }
3645
3646 static
3647 int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3648 struct lttng_kernel_ctx *ctx)
3649 {
3650 const char *prev_field_name = NULL;
3651 int ret = 0;
3652 int i;
3653
3654 if (!ctx)
3655 return 0;
3656 for (i = 0; i < ctx->nr_fields; i++) {
3657 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3658
3659 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3660 if (ret)
3661 return ret;
3662 }
3663 return ret;
3664 }
3665
3666 static
3667 int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3668 struct lttng_kernel_event_recorder *event_recorder)
3669 {
3670 const char *prev_field_name = NULL;
3671 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3672 int ret = 0;
3673 int i;
3674
3675 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3676 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3677
3678 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3679 if (ret)
3680 return ret;
3681 }
3682 return ret;
3683 }
3684
3685 /*
3686 * Must be called with sessions_mutex held.
3687 * The entire event metadata is printed as a single atomic metadata
3688 * transaction.
3689 */
3690 static
3691 int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
3692 struct lttng_kernel_channel_buffer *chan,
3693 struct lttng_kernel_event_recorder *event_recorder)
3694 {
3695 int ret = 0;
3696
3697 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3698 return 0;
3699 if (chan->priv->channel_type == METADATA_CHANNEL)
3700 return 0;
3701
3702 lttng_metadata_begin(session);
3703
3704 ret = lttng_metadata_printf(session,
3705 "event {\n"
3706 " name = \"%s\";\n"
3707 " id = %u;\n"
3708 " stream_id = %u;\n",
3709 event_recorder->priv->parent.desc->event_name,
3710 event_recorder->priv->id,
3711 event_recorder->chan->priv->id);
3712 if (ret)
3713 goto end;
3714
3715 ret = lttng_metadata_printf(session,
3716 " fields := struct {\n"
3717 );
3718 if (ret)
3719 goto end;
3720
3721 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3722 if (ret)
3723 goto end;
3724
3725 /*
3726 * LTTng space reservation can only reserve multiples of the
3727 * byte size.
3728 */
3729 ret = lttng_metadata_printf(session,
3730 " };\n"
3731 "};\n\n");
3732 if (ret)
3733 goto end;
3734
3735 event_recorder->priv->metadata_dumped = 1;
3736 end:
3737 lttng_metadata_end(session);
3738 return ret;
3739
3740 }
3741
3742 /*
3743 * Must be called with sessions_mutex held.
3744 * The entire channel metadata is printed as a single atomic metadata
3745 * transaction.
3746 */
3747 static
3748 int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3749 struct lttng_kernel_channel_buffer *chan)
3750 {
3751 int ret = 0;
3752
3753 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3754 return 0;
3755
3756 if (chan->priv->channel_type == METADATA_CHANNEL)
3757 return 0;
3758
3759 lttng_metadata_begin(session);
3760
3761 WARN_ON_ONCE(!chan->priv->header_type);
3762 ret = lttng_metadata_printf(session,
3763 "stream {\n"
3764 " id = %u;\n"
3765 " event.header := %s;\n"
3766 " packet.context := struct packet_context;\n",
3767 chan->priv->id,
3768 chan->priv->header_type == 1 ? "struct event_header_compact" :
3769 "struct event_header_large");
3770 if (ret)
3771 goto end;
3772
3773 if (chan->priv->ctx) {
3774 ret = lttng_metadata_printf(session,
3775 " event.context := struct {\n");
3776 if (ret)
3777 goto end;
3778 }
3779 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3780 if (ret)
3781 goto end;
3782 if (chan->priv->ctx) {
3783 ret = lttng_metadata_printf(session,
3784 " };\n");
3785 if (ret)
3786 goto end;
3787 }
3788
3789 ret = lttng_metadata_printf(session,
3790 "};\n\n");
3791
3792 chan->priv->metadata_dumped = 1;
3793 end:
3794 lttng_metadata_end(session);
3795 return ret;
3796 }
3797
3798 /*
3799 * Must be called with sessions_mutex held.
3800 */
3801 static
3802 int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3803 {
3804 return lttng_metadata_printf(session,
3805 "struct packet_context {\n"
3806 " uint64_clock_monotonic_t timestamp_begin;\n"
3807 " uint64_clock_monotonic_t timestamp_end;\n"
3808 " uint64_t content_size;\n"
3809 " uint64_t packet_size;\n"
3810 " uint64_t packet_seq_num;\n"
3811 " unsigned long events_discarded;\n"
3812 " uint32_t cpu_id;\n"
3813 "};\n\n"
3814 );
3815 }
3816
3817 /*
3818 * Compact header:
3819 * id: range: 0 - 30.
3820 * id 31 is reserved to indicate an extended header.
3821 *
3822 * Large header:
3823 * id: range: 0 - 65534.
3824 * id 65535 is reserved to indicate an extended header.
3825 *
3826 * Must be called with sessions_mutex held.
3827 */
3828 static
3829 int _lttng_event_header_declare(struct lttng_kernel_session *session)
3830 {
3831 return lttng_metadata_printf(session,
3832 "struct event_header_compact {\n"
3833 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3834 " variant <id> {\n"
3835 " struct {\n"
3836 " uint27_clock_monotonic_t timestamp;\n"
3837 " } compact;\n"
3838 " struct {\n"
3839 " uint32_t id;\n"
3840 " uint64_clock_monotonic_t timestamp;\n"
3841 " } extended;\n"
3842 " } v;\n"
3843 "} align(%u);\n"
3844 "\n"
3845 "struct event_header_large {\n"
3846 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3847 " variant <id> {\n"
3848 " struct {\n"
3849 " uint32_clock_monotonic_t timestamp;\n"
3850 " } compact;\n"
3851 " struct {\n"
3852 " uint32_t id;\n"
3853 " uint64_clock_monotonic_t timestamp;\n"
3854 " } extended;\n"
3855 " } v;\n"
3856 "} align(%u);\n\n",
3857 lttng_alignof(uint32_t) * CHAR_BIT,
3858 lttng_alignof(uint16_t) * CHAR_BIT
3859 );
3860 }
3861
3862 /*
3863 * Approximation of NTP time of day to clock monotonic correlation,
3864 * taken at start of trace.
3865 * Yes, this is only an approximation. Yes, we can (and will) do better
3866 * in future versions.
3867 * This function may return a negative offset. It may happen if the
3868 * system sets the REALTIME clock to 0 after boot.
3869 *
3870 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3871 * y2038 compliant.
3872 */
3873 static
3874 int64_t measure_clock_offset(void)
3875 {
3876 uint64_t monotonic_avg, monotonic[2], realtime;
3877 uint64_t tcf = trace_clock_freq();
3878 int64_t offset;
3879 unsigned long flags;
3880 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3881 struct timespec64 rts = { 0, 0 };
3882 #else
3883 struct timespec rts = { 0, 0 };
3884 #endif
3885
3886 /* Disable interrupts to increase correlation precision. */
3887 local_irq_save(flags);
3888 monotonic[0] = trace_clock_read64();
3889 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3890 ktime_get_real_ts64(&rts);
3891 #else
3892 getnstimeofday(&rts);
3893 #endif
3894 monotonic[1] = trace_clock_read64();
3895 local_irq_restore(flags);
3896
3897 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3898 realtime = (uint64_t) rts.tv_sec * tcf;
3899 if (tcf == NSEC_PER_SEC) {
3900 realtime += rts.tv_nsec;
3901 } else {
3902 uint64_t n = rts.tv_nsec * tcf;
3903
3904 do_div(n, NSEC_PER_SEC);
3905 realtime += n;
3906 }
3907 offset = (int64_t) realtime - monotonic_avg;
3908 return offset;
3909 }
3910
3911 static
3912 int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3913 {
3914 int ret = 0;
3915 size_t i;
3916 char cur;
3917
3918 i = 0;
3919 cur = string[i];
3920 while (cur != '\0') {
3921 switch (cur) {
3922 case '\n':
3923 ret = lttng_metadata_printf(session, "%s", "\\n");
3924 break;
3925 case '\\':
3926 case '"':
3927 ret = lttng_metadata_printf(session, "%c", '\\');
3928 if (ret)
3929 goto error;
3930 /* We still print the current char */
3931 lttng_fallthrough;
3932 default:
3933 ret = lttng_metadata_printf(session, "%c", cur);
3934 break;
3935 }
3936
3937 if (ret)
3938 goto error;
3939
3940 cur = string[++i];
3941 }
3942 error:
3943 return ret;
3944 }
3945
3946 static
3947 int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3948 const char *field_value)
3949 {
3950 int ret;
3951
3952 ret = lttng_metadata_printf(session, " %s = \"", field);
3953 if (ret)
3954 goto error;
3955
3956 ret = print_escaped_ctf_string(session, field_value);
3957 if (ret)
3958 goto error;
3959
3960 ret = lttng_metadata_printf(session, "\";\n");
3961
3962 error:
3963 return ret;
3964 }
3965
3966 /*
3967 * Output metadata into this session's metadata buffers.
3968 * Must be called with sessions_mutex held.
3969 */
3970 static
3971 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3972 {
3973 unsigned char *uuid_c = session->priv->uuid.b;
3974 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3975 const char *product_uuid;
3976 struct lttng_kernel_channel_buffer_private *chan_priv;
3977 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3978 int ret = 0;
3979
3980 if (!LTTNG_READ_ONCE(session->active))
3981 return 0;
3982
3983 lttng_metadata_begin(session);
3984
3985 if (session->priv->metadata_dumped)
3986 goto skip_session;
3987
3988 snprintf(uuid_s, sizeof(uuid_s),
3989 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3990 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3991 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3992 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3993 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3994
3995 ret = lttng_metadata_printf(session,
3996 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3997 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3998 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3999 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
4000 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
4001 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
4002 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
4003 "\n"
4004 "trace {\n"
4005 " major = %u;\n"
4006 " minor = %u;\n"
4007 " uuid = \"%s\";\n"
4008 " byte_order = %s;\n"
4009 " packet.header := struct {\n"
4010 " uint32_t magic;\n"
4011 " uint8_t uuid[16];\n"
4012 " uint32_t stream_id;\n"
4013 " uint64_t stream_instance_id;\n"
4014 " };\n"
4015 "};\n\n",
4016 lttng_alignof(uint8_t) * CHAR_BIT,
4017 lttng_alignof(uint16_t) * CHAR_BIT,
4018 lttng_alignof(uint32_t) * CHAR_BIT,
4019 lttng_alignof(uint64_t) * CHAR_BIT,
4020 sizeof(unsigned long) * CHAR_BIT,
4021 lttng_alignof(unsigned long) * CHAR_BIT,
4022 CTF_SPEC_MAJOR,
4023 CTF_SPEC_MINOR,
4024 uuid_s,
4025 #if __BYTE_ORDER == __BIG_ENDIAN
4026 "be"
4027 #else
4028 "le"
4029 #endif
4030 );
4031 if (ret)
4032 goto end;
4033
4034 ret = lttng_metadata_printf(session,
4035 "env {\n"
4036 " hostname = \"%s\";\n"
4037 " domain = \"kernel\";\n"
4038 " sysname = \"%s\";\n"
4039 " kernel_release = \"%s\";\n"
4040 " kernel_version = \"%s\";\n"
4041 " tracer_name = \"lttng-modules\";\n"
4042 " tracer_major = %d;\n"
4043 " tracer_minor = %d;\n"
4044 " tracer_patchlevel = %d;\n"
4045 " trace_buffering_scheme = \"global\";\n",
4046 current->nsproxy->uts_ns->name.nodename,
4047 utsname()->sysname,
4048 utsname()->release,
4049 utsname()->version,
4050 LTTNG_MODULES_MAJOR_VERSION,
4051 LTTNG_MODULES_MINOR_VERSION,
4052 LTTNG_MODULES_PATCHLEVEL_VERSION
4053 );
4054 if (ret)
4055 goto end;
4056
4057 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
4058 if (ret)
4059 goto end;
4060 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
4061 session->priv->creation_time);
4062 if (ret)
4063 goto end;
4064
4065 /* Add the product UUID to the 'env' section */
4066 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
4067 if (product_uuid) {
4068 ret = lttng_metadata_printf(session,
4069 " product_uuid = \"%s\";\n",
4070 product_uuid
4071 );
4072 if (ret)
4073 goto end;
4074 }
4075
4076 /* Close the 'env' section */
4077 ret = lttng_metadata_printf(session, "};\n\n");
4078 if (ret)
4079 goto end;
4080
4081 ret = lttng_metadata_printf(session,
4082 "clock {\n"
4083 " name = \"%s\";\n",
4084 trace_clock_name()
4085 );
4086 if (ret)
4087 goto end;
4088
4089 if (!trace_clock_uuid(clock_uuid_s)) {
4090 ret = lttng_metadata_printf(session,
4091 " uuid = \"%s\";\n",
4092 clock_uuid_s
4093 );
4094 if (ret)
4095 goto end;
4096 }
4097
4098 ret = lttng_metadata_printf(session,
4099 " description = \"%s\";\n"
4100 " freq = %llu; /* Frequency, in Hz */\n"
4101 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
4102 " offset = %lld;\n"
4103 "};\n\n",
4104 trace_clock_description(),
4105 (unsigned long long) trace_clock_freq(),
4106 (long long) measure_clock_offset()
4107 );
4108 if (ret)
4109 goto end;
4110
4111 ret = lttng_metadata_printf(session,
4112 "typealias integer {\n"
4113 " size = 27; align = 1; signed = false;\n"
4114 " map = clock.%s.value;\n"
4115 "} := uint27_clock_monotonic_t;\n"
4116 "\n"
4117 "typealias integer {\n"
4118 " size = 32; align = %u; signed = false;\n"
4119 " map = clock.%s.value;\n"
4120 "} := uint32_clock_monotonic_t;\n"
4121 "\n"
4122 "typealias integer {\n"
4123 " size = 64; align = %u; signed = false;\n"
4124 " map = clock.%s.value;\n"
4125 "} := uint64_clock_monotonic_t;\n\n",
4126 trace_clock_name(),
4127 lttng_alignof(uint32_t) * CHAR_BIT,
4128 trace_clock_name(),
4129 lttng_alignof(uint64_t) * CHAR_BIT,
4130 trace_clock_name()
4131 );
4132 if (ret)
4133 goto end;
4134
4135 ret = _lttng_stream_packet_context_declare(session);
4136 if (ret)
4137 goto end;
4138
4139 ret = _lttng_event_header_declare(session);
4140 if (ret)
4141 goto end;
4142
4143 skip_session:
4144 list_for_each_entry(chan_priv, &session->priv->chan, node) {
4145 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
4146 if (ret)
4147 goto end;
4148 }
4149
4150 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
4151 ret = _lttng_event_metadata_statedump(session, event_recorder_priv->pub->chan,
4152 event_recorder_priv->pub);
4153 if (ret)
4154 goto end;
4155 }
4156 session->priv->metadata_dumped = 1;
4157 end:
4158 lttng_metadata_end(session);
4159 return ret;
4160 }
4161
4162 /**
4163 * lttng_transport_register - LTT transport registration
4164 * @transport: transport structure
4165 *
4166 * Registers a transport which can be used as output to extract the data out of
4167 * LTTng. The module calling this registration function must ensure that no
4168 * trap-inducing code will be executed by the transport functions. E.g.
4169 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
4170 * is made visible to the transport function. This registration acts as a
4171 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
4172 * after its registration must it synchronize the TLBs.
4173 */
4174 void lttng_transport_register(struct lttng_transport *transport)
4175 {
4176 /*
4177 * Make sure no page fault can be triggered by the module about to be
4178 * registered. We deal with this here so we don't have to call
4179 * vmalloc_sync_mappings() in each module's init.
4180 */
4181 wrapper_vmalloc_sync_mappings();
4182
4183 mutex_lock(&sessions_mutex);
4184 list_add_tail(&transport->node, &lttng_transport_list);
4185 mutex_unlock(&sessions_mutex);
4186 }
4187 EXPORT_SYMBOL_GPL(lttng_transport_register);
4188
4189 /**
4190 * lttng_transport_unregister - LTT transport unregistration
4191 * @transport: transport structure
4192 */
4193 void lttng_transport_unregister(struct lttng_transport *transport)
4194 {
4195 mutex_lock(&sessions_mutex);
4196 list_del(&transport->node);
4197 mutex_unlock(&sessions_mutex);
4198 }
4199 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4200
4201 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4202 {
4203 /*
4204 * Make sure no page fault can be triggered by the module about to be
4205 * registered. We deal with this here so we don't have to call
4206 * vmalloc_sync_mappings() in each module's init.
4207 */
4208 wrapper_vmalloc_sync_mappings();
4209
4210 mutex_lock(&sessions_mutex);
4211 list_add_tail(&transport->node, &lttng_counter_transport_list);
4212 mutex_unlock(&sessions_mutex);
4213 }
4214 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4215
4216 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4217 {
4218 mutex_lock(&sessions_mutex);
4219 list_del(&transport->node);
4220 mutex_unlock(&sessions_mutex);
4221 }
4222 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4223
4224 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4225
4226 enum cpuhp_state lttng_hp_prepare;
4227 enum cpuhp_state lttng_hp_online;
4228
4229 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4230 {
4231 struct lttng_cpuhp_node *lttng_node;
4232
4233 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4234 switch (lttng_node->component) {
4235 case LTTNG_RING_BUFFER_FRONTEND:
4236 return 0;
4237 case LTTNG_RING_BUFFER_BACKEND:
4238 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4239 case LTTNG_RING_BUFFER_ITER:
4240 return 0;
4241 case LTTNG_CONTEXT_PERF_COUNTERS:
4242 return 0;
4243 default:
4244 return -EINVAL;
4245 }
4246 }
4247
4248 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4249 {
4250 struct lttng_cpuhp_node *lttng_node;
4251
4252 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4253 switch (lttng_node->component) {
4254 case LTTNG_RING_BUFFER_FRONTEND:
4255 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4256 case LTTNG_RING_BUFFER_BACKEND:
4257 return 0;
4258 case LTTNG_RING_BUFFER_ITER:
4259 return 0;
4260 case LTTNG_CONTEXT_PERF_COUNTERS:
4261 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4262 default:
4263 return -EINVAL;
4264 }
4265 }
4266
4267 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4268 {
4269 struct lttng_cpuhp_node *lttng_node;
4270
4271 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4272 switch (lttng_node->component) {
4273 case LTTNG_RING_BUFFER_FRONTEND:
4274 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4275 case LTTNG_RING_BUFFER_BACKEND:
4276 return 0;
4277 case LTTNG_RING_BUFFER_ITER:
4278 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4279 case LTTNG_CONTEXT_PERF_COUNTERS:
4280 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4281 default:
4282 return -EINVAL;
4283 }
4284 }
4285
4286 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4287 {
4288 struct lttng_cpuhp_node *lttng_node;
4289
4290 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4291 switch (lttng_node->component) {
4292 case LTTNG_RING_BUFFER_FRONTEND:
4293 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4294 case LTTNG_RING_BUFFER_BACKEND:
4295 return 0;
4296 case LTTNG_RING_BUFFER_ITER:
4297 return 0;
4298 case LTTNG_CONTEXT_PERF_COUNTERS:
4299 return 0;
4300 default:
4301 return -EINVAL;
4302 }
4303 }
4304
4305 static int __init lttng_init_cpu_hotplug(void)
4306 {
4307 int ret;
4308
4309 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4310 lttng_hotplug_prepare,
4311 lttng_hotplug_dead);
4312 if (ret < 0) {
4313 return ret;
4314 }
4315 lttng_hp_prepare = ret;
4316 lttng_rb_set_hp_prepare(ret);
4317
4318 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4319 lttng_hotplug_online,
4320 lttng_hotplug_offline);
4321 if (ret < 0) {
4322 cpuhp_remove_multi_state(lttng_hp_prepare);
4323 lttng_hp_prepare = 0;
4324 return ret;
4325 }
4326 lttng_hp_online = ret;
4327 lttng_rb_set_hp_online(ret);
4328
4329 return 0;
4330 }
4331
4332 static void __exit lttng_exit_cpu_hotplug(void)
4333 {
4334 lttng_rb_set_hp_online(0);
4335 cpuhp_remove_multi_state(lttng_hp_online);
4336 lttng_rb_set_hp_prepare(0);
4337 cpuhp_remove_multi_state(lttng_hp_prepare);
4338 }
4339
4340 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4341 static int lttng_init_cpu_hotplug(void)
4342 {
4343 return 0;
4344 }
4345 static void lttng_exit_cpu_hotplug(void)
4346 {
4347 }
4348 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4349
4350 static int __init lttng_events_init(void)
4351 {
4352 int ret;
4353
4354 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4355 if (ret)
4356 return ret;
4357 ret = wrapper_get_pfnblock_flags_mask_init();
4358 if (ret)
4359 return ret;
4360 ret = wrapper_get_pageblock_flags_mask_init();
4361 if (ret)
4362 return ret;
4363 ret = lttng_probes_init();
4364 if (ret)
4365 return ret;
4366 ret = lttng_context_init();
4367 if (ret)
4368 return ret;
4369 ret = lttng_tracepoint_init();
4370 if (ret)
4371 goto error_tp;
4372 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4373 if (!event_recorder_cache) {
4374 ret = -ENOMEM;
4375 goto error_kmem_event_recorder;
4376 }
4377 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4378 if (!event_recorder_private_cache) {
4379 ret = -ENOMEM;
4380 goto error_kmem_event_recorder_private;
4381 }
4382 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4383 if (!event_notifier_cache) {
4384 ret = -ENOMEM;
4385 goto error_kmem_event_notifier;
4386 }
4387 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4388 if (!event_notifier_private_cache) {
4389 ret = -ENOMEM;
4390 goto error_kmem_event_notifier_private;
4391 }
4392 ret = lttng_abi_init();
4393 if (ret)
4394 goto error_abi;
4395 ret = lttng_logger_init();
4396 if (ret)
4397 goto error_logger;
4398 ret = lttng_init_cpu_hotplug();
4399 if (ret)
4400 goto error_hotplug;
4401 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4402 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4403 __stringify(LTTNG_MODULES_MINOR_VERSION),
4404 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4405 LTTNG_MODULES_EXTRAVERSION,
4406 LTTNG_VERSION_NAME,
4407 #ifdef LTTNG_EXTRA_VERSION_GIT
4408 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4409 #else
4410 "",
4411 #endif
4412 #ifdef LTTNG_EXTRA_VERSION_NAME
4413 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4414 #else
4415 "");
4416 #endif
4417 #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
4418 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
4419 #endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
4420 return 0;
4421
4422 error_hotplug:
4423 lttng_logger_exit();
4424 error_logger:
4425 lttng_abi_exit();
4426 error_abi:
4427 kmem_cache_destroy(event_notifier_private_cache);
4428 error_kmem_event_notifier_private:
4429 kmem_cache_destroy(event_notifier_cache);
4430 error_kmem_event_notifier:
4431 kmem_cache_destroy(event_recorder_private_cache);
4432 error_kmem_event_recorder_private:
4433 kmem_cache_destroy(event_recorder_cache);
4434 error_kmem_event_recorder:
4435 lttng_tracepoint_exit();
4436 error_tp:
4437 lttng_context_exit();
4438 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4439 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4440 __stringify(LTTNG_MODULES_MINOR_VERSION),
4441 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4442 LTTNG_MODULES_EXTRAVERSION,
4443 LTTNG_VERSION_NAME,
4444 #ifdef LTTNG_EXTRA_VERSION_GIT
4445 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4446 #else
4447 "",
4448 #endif
4449 #ifdef LTTNG_EXTRA_VERSION_NAME
4450 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4451 #else
4452 "");
4453 #endif
4454 return ret;
4455 }
4456
4457 module_init(lttng_events_init);
4458
4459 static void __exit lttng_events_exit(void)
4460 {
4461 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4462
4463 lttng_exit_cpu_hotplug();
4464 lttng_logger_exit();
4465 lttng_abi_exit();
4466 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4467 lttng_session_destroy(session_priv->pub);
4468 kmem_cache_destroy(event_recorder_cache);
4469 kmem_cache_destroy(event_recorder_private_cache);
4470 kmem_cache_destroy(event_notifier_cache);
4471 kmem_cache_destroy(event_notifier_private_cache);
4472 lttng_tracepoint_exit();
4473 lttng_context_exit();
4474 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4475 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4476 __stringify(LTTNG_MODULES_MINOR_VERSION),
4477 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4478 LTTNG_MODULES_EXTRAVERSION,
4479 LTTNG_VERSION_NAME,
4480 #ifdef LTTNG_EXTRA_VERSION_GIT
4481 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4482 #else
4483 "",
4484 #endif
4485 #ifdef LTTNG_EXTRA_VERSION_NAME
4486 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4487 #else
4488 "");
4489 #endif
4490 }
4491
4492 module_exit(lttng_events_exit);
4493
4494 #include <generated/patches.h>
4495 #ifdef LTTNG_EXTRA_VERSION_GIT
4496 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4497 #endif
4498 #ifdef LTTNG_EXTRA_VERSION_NAME
4499 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4500 #endif
4501 MODULE_LICENSE("GPL and additional rights");
4502 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4503 MODULE_DESCRIPTION("LTTng tracer");
4504 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4505 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4506 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4507 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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