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