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Inline implementation of task_prio()
[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 struct lttng_kernel_id_tracker *get_tracker(struct lttng_kernel_session *session,
1551 enum tracker_type tracker_type)
1552 {
1553 switch (tracker_type) {
1554 case TRACKER_PID:
1555 return &session->pid_tracker;
1556 case TRACKER_VPID:
1557 return &session->vpid_tracker;
1558 case TRACKER_UID:
1559 return &session->uid_tracker;
1560 case TRACKER_VUID:
1561 return &session->vuid_tracker;
1562 case TRACKER_GID:
1563 return &session->gid_tracker;
1564 case TRACKER_VGID:
1565 return &session->vgid_tracker;
1566 default:
1567 WARN_ON_ONCE(1);
1568 return NULL;
1569 }
1570 }
1571
1572 int lttng_session_track_id(struct lttng_kernel_session *session,
1573 enum tracker_type tracker_type, int id)
1574 {
1575 struct lttng_kernel_id_tracker *tracker;
1576 int ret;
1577
1578 tracker = get_tracker(session, tracker_type);
1579 if (!tracker)
1580 return -EINVAL;
1581 if (id < -1)
1582 return -EINVAL;
1583 mutex_lock(&sessions_mutex);
1584 if (id == -1) {
1585 /* track all ids: destroy tracker. */
1586 lttng_id_tracker_destroy(tracker, true);
1587 ret = 0;
1588 } else {
1589 ret = lttng_id_tracker_add(tracker, id);
1590 }
1591 mutex_unlock(&sessions_mutex);
1592 return ret;
1593 }
1594
1595 int lttng_session_untrack_id(struct lttng_kernel_session *session,
1596 enum tracker_type tracker_type, int id)
1597 {
1598 struct lttng_kernel_id_tracker *tracker;
1599 int ret;
1600
1601 tracker = get_tracker(session, tracker_type);
1602 if (!tracker)
1603 return -EINVAL;
1604 if (id < -1)
1605 return -EINVAL;
1606 mutex_lock(&sessions_mutex);
1607 if (id == -1) {
1608 /* untrack all ids: replace by empty tracker. */
1609 ret = lttng_id_tracker_empty_set(tracker);
1610 } else {
1611 ret = lttng_id_tracker_del(tracker, id);
1612 }
1613 mutex_unlock(&sessions_mutex);
1614 return ret;
1615 }
1616
1617 static
1618 void *id_list_start(struct seq_file *m, loff_t *pos)
1619 {
1620 struct lttng_kernel_id_tracker *id_tracker = m->private;
1621 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1622 struct lttng_id_hash_node *e;
1623 int iter = 0, i;
1624
1625 mutex_lock(&sessions_mutex);
1626 if (id_tracker_p) {
1627 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1628 struct hlist_head *head = &id_tracker_p->id_hash[i];
1629
1630 lttng_hlist_for_each_entry(e, head, hlist) {
1631 if (iter++ >= *pos)
1632 return e;
1633 }
1634 }
1635 } else {
1636 /* ID tracker disabled. */
1637 if (iter >= *pos && iter == 0) {
1638 return id_tracker_p; /* empty tracker */
1639 }
1640 iter++;
1641 }
1642 /* End of list */
1643 return NULL;
1644 }
1645
1646 /* Called with sessions_mutex held. */
1647 static
1648 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1649 {
1650 struct lttng_kernel_id_tracker *id_tracker = m->private;
1651 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1652 struct lttng_id_hash_node *e;
1653 int iter = 0, i;
1654
1655 (*ppos)++;
1656 if (id_tracker_p) {
1657 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1658 struct hlist_head *head = &id_tracker_p->id_hash[i];
1659
1660 lttng_hlist_for_each_entry(e, head, hlist) {
1661 if (iter++ >= *ppos)
1662 return e;
1663 }
1664 }
1665 } else {
1666 /* ID tracker disabled. */
1667 if (iter >= *ppos && iter == 0)
1668 return p; /* empty tracker */
1669 iter++;
1670 }
1671
1672 /* End of list */
1673 return NULL;
1674 }
1675
1676 static
1677 void id_list_stop(struct seq_file *m, void *p)
1678 {
1679 mutex_unlock(&sessions_mutex);
1680 }
1681
1682 static
1683 int id_list_show(struct seq_file *m, void *p)
1684 {
1685 struct lttng_kernel_id_tracker *id_tracker = m->private;
1686 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1687 int id;
1688
1689 if (p == id_tracker_p) {
1690 /* Tracker disabled. */
1691 id = -1;
1692 } else {
1693 const struct lttng_id_hash_node *e = p;
1694
1695 id = lttng_id_tracker_get_node_id(e);
1696 }
1697 switch (id_tracker->priv->tracker_type) {
1698 case TRACKER_PID:
1699 seq_printf(m, "process { pid = %d; };\n", id);
1700 break;
1701 case TRACKER_VPID:
1702 seq_printf(m, "process { vpid = %d; };\n", id);
1703 break;
1704 case TRACKER_UID:
1705 seq_printf(m, "user { uid = %d; };\n", id);
1706 break;
1707 case TRACKER_VUID:
1708 seq_printf(m, "user { vuid = %d; };\n", id);
1709 break;
1710 case TRACKER_GID:
1711 seq_printf(m, "group { gid = %d; };\n", id);
1712 break;
1713 case TRACKER_VGID:
1714 seq_printf(m, "group { vgid = %d; };\n", id);
1715 break;
1716 default:
1717 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1718 }
1719 return 0;
1720 }
1721
1722 static
1723 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1724 .start = id_list_start,
1725 .next = id_list_next,
1726 .stop = id_list_stop,
1727 .show = id_list_show,
1728 };
1729
1730 static
1731 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1732 {
1733 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1734 }
1735
1736 static
1737 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1738 {
1739 struct seq_file *m = file->private_data;
1740 struct lttng_kernel_id_tracker *id_tracker = m->private;
1741 int ret;
1742
1743 WARN_ON_ONCE(!id_tracker);
1744 ret = seq_release(inode, file);
1745 if (!ret)
1746 fput(id_tracker->priv->session->priv->file);
1747 return ret;
1748 }
1749
1750 const struct file_operations lttng_tracker_ids_list_fops = {
1751 .owner = THIS_MODULE,
1752 .open = lttng_tracker_ids_list_open,
1753 .read = seq_read,
1754 .llseek = seq_lseek,
1755 .release = lttng_tracker_ids_list_release,
1756 };
1757
1758 int lttng_session_list_tracker_ids(struct lttng_kernel_session *session,
1759 enum tracker_type tracker_type)
1760 {
1761 struct file *tracker_ids_list_file;
1762 struct seq_file *m;
1763 int file_fd, ret;
1764
1765 file_fd = get_unused_fd_flags(0);
1766 if (file_fd < 0) {
1767 ret = file_fd;
1768 goto fd_error;
1769 }
1770
1771 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1772 &lttng_tracker_ids_list_fops,
1773 NULL, O_RDWR);
1774 if (IS_ERR(tracker_ids_list_file)) {
1775 ret = PTR_ERR(tracker_ids_list_file);
1776 goto file_error;
1777 }
1778 if (!atomic_long_add_unless(&session->priv->file->f_count, 1, LONG_MAX)) {
1779 ret = -EOVERFLOW;
1780 goto refcount_error;
1781 }
1782 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1783 if (ret < 0)
1784 goto open_error;
1785 m = tracker_ids_list_file->private_data;
1786
1787 m->private = get_tracker(session, tracker_type);
1788 BUG_ON(!m->private);
1789 fd_install(file_fd, tracker_ids_list_file);
1790
1791 return file_fd;
1792
1793 open_error:
1794 atomic_long_dec(&session->priv->file->f_count);
1795 refcount_error:
1796 fput(tracker_ids_list_file);
1797 file_error:
1798 put_unused_fd(file_fd);
1799 fd_error:
1800 return ret;
1801 }
1802
1803 /*
1804 * Enabler management.
1805 */
1806 static
1807 int lttng_match_enabler_star_glob(const char *desc_name,
1808 const char *pattern)
1809 {
1810 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1811 desc_name, LTTNG_SIZE_MAX))
1812 return 0;
1813 return 1;
1814 }
1815
1816 static
1817 int lttng_match_enabler_name(const char *desc_name,
1818 const char *name)
1819 {
1820 if (strcmp(desc_name, name))
1821 return 0;
1822 return 1;
1823 }
1824
1825 static
1826 int lttng_desc_match_enabler_check(const struct lttng_kernel_event_desc *desc,
1827 struct lttng_event_enabler_common *enabler)
1828 {
1829 const char *desc_name, *enabler_name;
1830 bool compat = false, entry = false;
1831
1832 enabler_name = enabler->event_param.name;
1833 switch (enabler->event_param.instrumentation) {
1834 case LTTNG_KERNEL_ABI_TRACEPOINT:
1835 desc_name = desc->event_name;
1836 switch (enabler->format_type) {
1837 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1838 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1839 case LTTNG_ENABLER_FORMAT_NAME:
1840 return lttng_match_enabler_name(desc_name, enabler_name);
1841 default:
1842 return -EINVAL;
1843 }
1844 break;
1845
1846 case LTTNG_KERNEL_ABI_SYSCALL:
1847 desc_name = desc->event_name;
1848 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1849 desc_name += strlen("compat_");
1850 compat = true;
1851 }
1852 if (!strncmp(desc_name, "syscall_exit_",
1853 strlen("syscall_exit_"))) {
1854 desc_name += strlen("syscall_exit_");
1855 } else if (!strncmp(desc_name, "syscall_entry_",
1856 strlen("syscall_entry_"))) {
1857 desc_name += strlen("syscall_entry_");
1858 entry = true;
1859 } else {
1860 WARN_ON_ONCE(1);
1861 return -EINVAL;
1862 }
1863 switch (enabler->event_param.u.syscall.entryexit) {
1864 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1865 break;
1866 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1867 if (!entry)
1868 return 0;
1869 break;
1870 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1871 if (entry)
1872 return 0;
1873 break;
1874 default:
1875 return -EINVAL;
1876 }
1877 switch (enabler->event_param.u.syscall.abi) {
1878 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1879 break;
1880 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1881 if (compat)
1882 return 0;
1883 break;
1884 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1885 if (!compat)
1886 return 0;
1887 break;
1888 default:
1889 return -EINVAL;
1890 }
1891 switch (enabler->event_param.u.syscall.match) {
1892 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
1893 switch (enabler->format_type) {
1894 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1895 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1896 case LTTNG_ENABLER_FORMAT_NAME:
1897 return lttng_match_enabler_name(desc_name, enabler_name);
1898 default:
1899 return -EINVAL;
1900 }
1901 break;
1902 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
1903 return -EINVAL; /* Not implemented. */
1904 default:
1905 return -EINVAL;
1906 }
1907 break;
1908
1909 default:
1910 WARN_ON_ONCE(1);
1911 return -EINVAL;
1912 }
1913 }
1914
1915 bool lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
1916 struct lttng_event_enabler_common *enabler)
1917 {
1918 int ret;
1919
1920 ret = lttng_desc_match_enabler_check(desc, enabler);
1921 if (ret < 0) {
1922 WARN_ON_ONCE(1);
1923 return false;
1924 }
1925 return ret;
1926 }
1927
1928 bool lttng_event_enabler_match_event(struct lttng_event_enabler_common *event_enabler,
1929 struct lttng_kernel_event_common *event)
1930 {
1931 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
1932 return false;
1933
1934 switch (event_enabler->enabler_type) {
1935 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
1936 {
1937 struct lttng_event_recorder_enabler *event_recorder_enabler =
1938 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
1939 struct lttng_kernel_event_recorder *event_recorder =
1940 container_of(event, struct lttng_kernel_event_recorder, parent);
1941
1942 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
1943 && event_recorder->chan == event_recorder_enabler->chan)
1944 return true;
1945 else
1946 return false;
1947 }
1948 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
1949 {
1950 struct lttng_event_notifier_enabler *event_notifier_enabler =
1951 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
1952 struct lttng_kernel_event_notifier *event_notifier =
1953 container_of(event, struct lttng_kernel_event_notifier, parent);
1954
1955 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
1956 && event_notifier->priv->group == event_notifier_enabler->group
1957 && event->priv->user_token == event_enabler->user_token)
1958 return true;
1959 else
1960 return false;
1961 }
1962 default:
1963 WARN_ON_ONCE(1);
1964 return false;
1965 }
1966 }
1967
1968 bool lttng_event_enabler_desc_match_event(struct lttng_event_enabler_common *event_enabler,
1969 const struct lttng_kernel_event_desc *desc,
1970 struct lttng_kernel_event_common *event)
1971 {
1972 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
1973 return false;
1974
1975 switch (event_enabler->enabler_type) {
1976 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
1977 {
1978 struct lttng_event_recorder_enabler *event_recorder_enabler =
1979 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
1980 struct lttng_kernel_event_recorder *event_recorder =
1981 container_of(event, struct lttng_kernel_event_recorder, parent);
1982
1983 if (event->priv->desc == desc && event_recorder->chan == event_recorder_enabler->chan)
1984 return true;
1985 else
1986 return false;
1987 }
1988 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
1989 {
1990 struct lttng_event_notifier_enabler *event_notifier_enabler =
1991 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
1992 struct lttng_kernel_event_notifier *event_notifier =
1993 container_of(event, struct lttng_kernel_event_notifier, parent);
1994
1995 if (event->priv->desc == desc
1996 && event_notifier->priv->group == event_notifier_enabler->group
1997 && event->priv->user_token == event_enabler->user_token)
1998 return true;
1999 else
2000 return false;
2001 }
2002 default:
2003 WARN_ON_ONCE(1);
2004 return false;
2005 }
2006 }
2007
2008 bool lttng_event_enabler_event_name_match_event(struct lttng_event_enabler_common *event_enabler,
2009 const char *event_name,
2010 struct lttng_kernel_event_common *event)
2011 {
2012 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2013 return false;
2014
2015 switch (event_enabler->enabler_type) {
2016 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2017 {
2018 struct lttng_event_recorder_enabler *event_recorder_enabler =
2019 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2020 struct lttng_kernel_event_recorder *event_recorder =
2021 container_of(event, struct lttng_kernel_event_recorder, parent);
2022
2023 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2024 && event_recorder->chan == event_recorder_enabler->chan)
2025 return true;
2026 else
2027 return false;
2028 }
2029 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2030 {
2031 struct lttng_event_notifier_enabler *event_notifier_enabler =
2032 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2033 struct lttng_kernel_event_notifier *event_notifier =
2034 container_of(event, struct lttng_kernel_event_notifier, parent);
2035
2036 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2037 && event_notifier->priv->group == event_notifier_enabler->group
2038 && event->priv->user_token == event_enabler->user_token)
2039 return true;
2040 else
2041 return false;
2042 }
2043 default:
2044 WARN_ON_ONCE(1);
2045 return false;
2046 }
2047 }
2048
2049 static
2050 struct lttng_enabler_ref *lttng_enabler_ref(
2051 struct list_head *enablers_ref_list,
2052 struct lttng_event_enabler_common *enabler)
2053 {
2054 struct lttng_enabler_ref *enabler_ref;
2055
2056 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2057 if (enabler_ref->ref == enabler)
2058 return enabler_ref;
2059 }
2060 return NULL;
2061 }
2062
2063 static
2064 void lttng_event_enabler_create_tracepoint_events_if_missing(struct lttng_event_enabler_common *event_enabler)
2065 {
2066 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(event_enabler);
2067 struct lttng_kernel_probe_desc *probe_desc;
2068 const struct lttng_kernel_event_desc *desc;
2069 struct list_head *probe_list;
2070 int i;
2071
2072 probe_list = lttng_get_probe_list_head();
2073 /*
2074 * For each probe event, if we find that a probe event matches
2075 * our enabler, create an associated lttng_event if not
2076 * already present.
2077 */
2078 list_for_each_entry(probe_desc, probe_list, head) {
2079 for (i = 0; i < probe_desc->nr_events; i++) {
2080 bool found = false;
2081 struct hlist_head *head;
2082 struct lttng_kernel_event_common *event;
2083 struct lttng_kernel_event_common_private *event_priv;
2084
2085 desc = probe_desc->event_desc[i];
2086 if (!lttng_desc_match_enabler(desc, event_enabler))
2087 continue;
2088
2089 /*
2090 * Check if already created.
2091 */
2092 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
2093 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
2094 if (lttng_event_enabler_desc_match_event(event_enabler, desc, event_priv->pub)) {
2095 found = true;
2096 break;
2097 }
2098 }
2099 if (found)
2100 continue;
2101
2102 /*
2103 * We need to create an event for this event probe.
2104 */
2105 event = _lttng_kernel_event_create(event_enabler, desc);
2106 if (IS_ERR(event)) {
2107 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2108 probe_desc->event_desc[i]->event_name);
2109 }
2110 }
2111 }
2112 }
2113
2114 /*
2115 * Create event if it is missing and present in the list of tracepoint probes.
2116 * Should be called with sessions mutex held.
2117 */
2118 static
2119 void lttng_event_enabler_create_events_if_missing(struct lttng_event_enabler_common *event_enabler)
2120 {
2121 int ret;
2122
2123 switch (event_enabler->event_param.instrumentation) {
2124 case LTTNG_KERNEL_ABI_TRACEPOINT:
2125 lttng_event_enabler_create_tracepoint_events_if_missing(event_enabler);
2126 break;
2127
2128 case LTTNG_KERNEL_ABI_SYSCALL:
2129 ret = lttng_event_enabler_create_syscall_events_if_missing(event_enabler);
2130 WARN_ON_ONCE(ret);
2131 break;
2132
2133 default:
2134 WARN_ON_ONCE(1);
2135 break;
2136 }
2137 }
2138
2139 static
2140 void lttng_event_enabler_init_event_filter(struct lttng_event_enabler_common *event_enabler,
2141 struct lttng_kernel_event_common *event)
2142 {
2143 /* Link filter bytecodes if not linked yet. */
2144 lttng_enabler_link_bytecode(event->priv->desc, lttng_static_ctx,
2145 &event->priv->filter_bytecode_runtime_head, &event_enabler->filter_bytecode_head);
2146 }
2147
2148 static
2149 void lttng_event_enabler_init_event_capture(struct lttng_event_enabler_common *event_enabler,
2150 struct lttng_kernel_event_common *event)
2151 {
2152 switch (event_enabler->enabler_type) {
2153 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2154 break;
2155 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2156 {
2157 struct lttng_event_notifier_enabler *event_notifier_enabler =
2158 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2159 struct lttng_kernel_event_notifier *event_notifier =
2160 container_of(event, struct lttng_kernel_event_notifier, parent);
2161
2162 /* Link capture bytecodes if not linked yet. */
2163 lttng_enabler_link_bytecode(event->priv->desc,
2164 lttng_static_ctx, &event_notifier->priv->capture_bytecode_runtime_head,
2165 &event_notifier_enabler->capture_bytecode_head);
2166 event_notifier->priv->num_captures = event_notifier_enabler->num_captures;
2167 break;
2168 }
2169 default:
2170 WARN_ON_ONCE(1);
2171 }
2172 }
2173
2174 /*
2175 * Create events associated with an event_enabler (if not already present),
2176 * and add backward reference from the event to the enabler.
2177 * Should be called with sessions mutex held.
2178 */
2179 static
2180 int lttng_event_enabler_ref_events(struct lttng_event_enabler_common *event_enabler)
2181 {
2182 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(event_enabler);
2183 struct lttng_kernel_event_common_private *event_priv;
2184
2185 lttng_syscall_table_set_wildcard_all(event_enabler);
2186
2187 /* First ensure that probe events are created for this enabler. */
2188 lttng_event_enabler_create_events_if_missing(event_enabler);
2189
2190 /* Link the created event with its associated enabler. */
2191 list_for_each_entry(event_priv, event_list_head, node) {
2192 struct lttng_kernel_event_common *event = event_priv->pub;
2193 struct lttng_enabler_ref *enabler_ref;
2194
2195 if (!lttng_event_enabler_match_event(event_enabler, event))
2196 continue;
2197
2198 enabler_ref = lttng_enabler_ref(&event_priv->enablers_ref_head, event_enabler);
2199 if (!enabler_ref) {
2200 /*
2201 * If no backward ref, create it.
2202 * Add backward ref from event_notifier to enabler.
2203 */
2204 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2205 if (!enabler_ref)
2206 return -ENOMEM;
2207
2208 enabler_ref->ref = event_enabler;
2209 list_add(&enabler_ref->node, &event_priv->enablers_ref_head);
2210 }
2211
2212 lttng_event_enabler_init_event_filter(event_enabler, event);
2213 lttng_event_enabler_init_event_capture(event_enabler, event);
2214 }
2215 return 0;
2216 }
2217
2218 /*
2219 * Called at module load: connect the probe on all enablers matching
2220 * this event.
2221 * Called with sessions lock held.
2222 */
2223 int lttng_fix_pending_events(void)
2224 {
2225 struct lttng_kernel_session_private *session_priv;
2226
2227 list_for_each_entry(session_priv, &sessions, list)
2228 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2229 return 0;
2230 }
2231
2232 static bool lttng_event_notifier_group_has_active_event_notifiers(
2233 struct lttng_event_notifier_group *event_notifier_group)
2234 {
2235 struct lttng_event_enabler_common *event_enabler;
2236
2237 list_for_each_entry(event_enabler, &event_notifier_group->enablers_head, node) {
2238 if (event_enabler->enabled)
2239 return true;
2240 }
2241 return false;
2242 }
2243
2244 bool lttng_event_notifier_active(void)
2245 {
2246 struct lttng_event_notifier_group *event_notifier_group;
2247
2248 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2249 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2250 return true;
2251 }
2252 return false;
2253 }
2254
2255 int lttng_fix_pending_event_notifiers(void)
2256 {
2257 struct lttng_event_notifier_group *event_notifier_group;
2258
2259 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2260 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2261 return 0;
2262 }
2263
2264 struct lttng_event_recorder_enabler *lttng_event_recorder_enabler_create(
2265 enum lttng_enabler_format_type format_type,
2266 struct lttng_kernel_abi_event *event_param,
2267 struct lttng_kernel_channel_buffer *chan)
2268 {
2269 struct lttng_event_recorder_enabler *event_enabler;
2270
2271 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2272 if (!event_enabler)
2273 return NULL;
2274 event_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_RECORDER;
2275 event_enabler->parent.format_type = format_type;
2276 INIT_LIST_HEAD(&event_enabler->parent.filter_bytecode_head);
2277 memcpy(&event_enabler->parent.event_param, event_param,
2278 sizeof(event_enabler->parent.event_param));
2279 event_enabler->chan = chan;
2280 /* ctx left NULL */
2281 event_enabler->parent.enabled = 0;
2282 return event_enabler;
2283 }
2284
2285 void lttng_event_enabler_session_add(struct lttng_kernel_session *session,
2286 struct lttng_event_recorder_enabler *event_enabler)
2287 {
2288 mutex_lock(&sessions_mutex);
2289 list_add(&event_enabler->parent.node, &session->priv->enablers_head);
2290 event_enabler->parent.published = true;
2291 lttng_session_lazy_sync_event_enablers(session);
2292 mutex_unlock(&sessions_mutex);
2293 }
2294
2295 int lttng_event_enabler_enable(struct lttng_event_enabler_common *event_enabler)
2296 {
2297 mutex_lock(&sessions_mutex);
2298 event_enabler->enabled = 1;
2299 lttng_event_enabler_sync(event_enabler);
2300 mutex_unlock(&sessions_mutex);
2301 return 0;
2302 }
2303
2304 int lttng_event_enabler_disable(struct lttng_event_enabler_common *event_enabler)
2305 {
2306 mutex_lock(&sessions_mutex);
2307 event_enabler->enabled = 0;
2308 lttng_event_enabler_sync(event_enabler);
2309 mutex_unlock(&sessions_mutex);
2310 return 0;
2311 }
2312
2313 static
2314 int lttng_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *enabler,
2315 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2316 {
2317 struct lttng_kernel_bytecode_node *bytecode_node;
2318 uint32_t bytecode_len;
2319 int ret;
2320
2321 ret = get_user(bytecode_len, &bytecode->len);
2322 if (ret)
2323 return ret;
2324 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2325 GFP_KERNEL);
2326 if (!bytecode_node)
2327 return -ENOMEM;
2328 ret = copy_from_user(&bytecode_node->bc, bytecode,
2329 sizeof(*bytecode) + bytecode_len);
2330 if (ret)
2331 goto error_free;
2332
2333 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2334 bytecode_node->enabler = enabler;
2335 /* Enforce length based on allocated size */
2336 bytecode_node->bc.len = bytecode_len;
2337 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2338
2339 return 0;
2340
2341 error_free:
2342 lttng_kvfree(bytecode_node);
2343 return ret;
2344 }
2345
2346 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *event_enabler,
2347 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2348 {
2349 int ret;
2350 ret = lttng_enabler_attach_filter_bytecode(event_enabler, bytecode);
2351 if (ret)
2352 goto error;
2353 lttng_event_enabler_sync(event_enabler);
2354 return 0;
2355
2356 error:
2357 return ret;
2358 }
2359
2360 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2361 struct lttng_kernel_abi_event_callsite __user *callsite)
2362 {
2363
2364 switch (event->priv->instrumentation) {
2365 case LTTNG_KERNEL_ABI_UPROBE:
2366 return lttng_uprobes_event_add_callsite(event, callsite);
2367 default:
2368 return -EINVAL;
2369 }
2370 }
2371
2372 static
2373 void lttng_enabler_destroy(struct lttng_event_enabler_common *enabler)
2374 {
2375 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2376
2377 /* Destroy filter bytecode */
2378 list_for_each_entry_safe(filter_node, tmp_filter_node,
2379 &enabler->filter_bytecode_head, node) {
2380 lttng_kvfree(filter_node);
2381 }
2382 }
2383
2384 void lttng_event_enabler_destroy(struct lttng_event_enabler_common *event_enabler)
2385 {
2386 lttng_enabler_destroy(event_enabler);
2387 if (event_enabler->published)
2388 list_del(&event_enabler->node);
2389
2390 switch (event_enabler->enabler_type) {
2391 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2392 {
2393 struct lttng_event_recorder_enabler *event_recorder_enabler =
2394 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2395
2396 kfree(event_recorder_enabler);
2397 break;
2398 }
2399 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2400 {
2401 struct lttng_event_notifier_enabler *event_notifier_enabler =
2402 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2403
2404 kfree(event_notifier_enabler);
2405 break;
2406 }
2407 default:
2408 WARN_ON_ONCE(1);
2409 }
2410 }
2411
2412 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2413 enum lttng_enabler_format_type format_type,
2414 struct lttng_kernel_abi_event_notifier *event_notifier_param,
2415 struct lttng_event_notifier_group *event_notifier_group)
2416 {
2417 struct lttng_event_notifier_enabler *event_notifier_enabler;
2418
2419 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2420 if (!event_notifier_enabler)
2421 return NULL;
2422
2423 event_notifier_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_NOTIFIER;
2424 event_notifier_enabler->parent.format_type = format_type;
2425 INIT_LIST_HEAD(&event_notifier_enabler->parent.filter_bytecode_head);
2426 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2427
2428 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2429 event_notifier_enabler->num_captures = 0;
2430
2431 memcpy(&event_notifier_enabler->parent.event_param, &event_notifier_param->event,
2432 sizeof(event_notifier_enabler->parent.event_param));
2433
2434 event_notifier_enabler->parent.enabled = 0;
2435 event_notifier_enabler->parent.user_token = event_notifier_param->event.token;
2436 event_notifier_enabler->group = event_notifier_group;
2437 return event_notifier_enabler;
2438 }
2439
2440 void lttng_event_notifier_enabler_group_add(struct lttng_event_notifier_group *event_notifier_group,
2441 struct lttng_event_notifier_enabler *event_notifier_enabler)
2442 {
2443 mutex_lock(&sessions_mutex);
2444 list_add(&event_notifier_enabler->parent.node, &event_notifier_enabler->group->enablers_head);
2445 event_notifier_enabler->parent.published = true;
2446 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2447 mutex_unlock(&sessions_mutex);
2448 }
2449
2450 int lttng_event_notifier_enabler_enable(
2451 struct lttng_event_notifier_enabler *event_notifier_enabler)
2452 {
2453 mutex_lock(&sessions_mutex);
2454 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2455 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2456 mutex_unlock(&sessions_mutex);
2457 return 0;
2458 }
2459
2460 int lttng_event_notifier_enabler_disable(
2461 struct lttng_event_notifier_enabler *event_notifier_enabler)
2462 {
2463 mutex_lock(&sessions_mutex);
2464 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2465 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2466 mutex_unlock(&sessions_mutex);
2467 return 0;
2468 }
2469
2470 int lttng_event_notifier_enabler_attach_capture_bytecode(
2471 struct lttng_event_notifier_enabler *event_notifier_enabler,
2472 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2473 {
2474 struct lttng_kernel_bytecode_node *bytecode_node;
2475 struct lttng_event_enabler_common *enabler =
2476 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2477 uint32_t bytecode_len;
2478 int ret;
2479
2480 ret = get_user(bytecode_len, &bytecode->len);
2481 if (ret)
2482 return ret;
2483
2484 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2485 GFP_KERNEL);
2486 if (!bytecode_node)
2487 return -ENOMEM;
2488
2489 ret = copy_from_user(&bytecode_node->bc, bytecode,
2490 sizeof(*bytecode) + bytecode_len);
2491 if (ret)
2492 goto error_free;
2493
2494 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2495 bytecode_node->enabler = enabler;
2496
2497 /* Enforce length based on allocated size */
2498 bytecode_node->bc.len = bytecode_len;
2499 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2500
2501 event_notifier_enabler->num_captures++;
2502
2503 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2504 goto end;
2505
2506 error_free:
2507 lttng_kvfree(bytecode_node);
2508 end:
2509 return ret;
2510 }
2511
2512 static
2513 void lttng_event_sync_filter_state(struct lttng_kernel_event_common *event)
2514 {
2515 int has_enablers_without_filter_bytecode = 0, nr_filters = 0;
2516 struct lttng_kernel_bytecode_runtime *runtime;
2517 struct lttng_enabler_ref *enabler_ref;
2518
2519 /* Check if has enablers without bytecode enabled */
2520 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2521 if (enabler_ref->ref->enabled
2522 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2523 has_enablers_without_filter_bytecode = 1;
2524 break;
2525 }
2526 }
2527 event->priv->has_enablers_without_filter_bytecode = has_enablers_without_filter_bytecode;
2528
2529 /* Enable filters */
2530 list_for_each_entry(runtime, &event->priv->filter_bytecode_runtime_head, node) {
2531 lttng_bytecode_sync_state(runtime);
2532 nr_filters++;
2533 }
2534 WRITE_ONCE(event->eval_filter, !(has_enablers_without_filter_bytecode || !nr_filters));
2535 }
2536
2537 static
2538 void lttng_event_sync_capture_state(struct lttng_kernel_event_common *event)
2539 {
2540 switch (event->type) {
2541 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2542 break;
2543 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2544 {
2545 struct lttng_kernel_event_notifier *event_notifier =
2546 container_of(event, struct lttng_kernel_event_notifier, parent);
2547 struct lttng_kernel_bytecode_runtime *runtime;
2548 int nr_captures = 0;
2549
2550 /* Enable captures */
2551 list_for_each_entry(runtime, &event_notifier->priv->capture_bytecode_runtime_head, node) {
2552 lttng_bytecode_sync_state(runtime);
2553 nr_captures++;
2554 }
2555 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2556 break;
2557 }
2558 default:
2559 WARN_ON_ONCE(1);
2560 }
2561 }
2562
2563 static
2564 bool lttng_get_event_enabled_state(struct lttng_kernel_event_common *event)
2565 {
2566 struct lttng_enabler_ref *enabler_ref;
2567 bool enabled = false;
2568
2569 switch (event->priv->instrumentation) {
2570 case LTTNG_KERNEL_ABI_TRACEPOINT:
2571 lttng_fallthrough;
2572 case LTTNG_KERNEL_ABI_SYSCALL:
2573 /* Enable events */
2574 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2575 if (enabler_ref->ref->enabled) {
2576 enabled = true;
2577 break;
2578 }
2579 }
2580 break;
2581 default:
2582 WARN_ON_ONCE(1);
2583 return false;
2584 }
2585
2586 switch (event->type) {
2587 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2588 {
2589 struct lttng_kernel_event_recorder *event_recorder =
2590 container_of(event, struct lttng_kernel_event_recorder, parent);
2591
2592 /*
2593 * Enabled state is based on union of enablers, with
2594 * intersection of session and channel transient enable
2595 * states.
2596 */
2597 return enabled && event_recorder->chan->parent.session->priv->tstate && event_recorder->chan->priv->parent.tstate;
2598 }
2599 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2600 return enabled;
2601 default:
2602 WARN_ON_ONCE(1);
2603 return false;
2604 }
2605 }
2606
2607 static
2608 bool lttng_event_is_lazy_sync(struct lttng_kernel_event_common *event)
2609 {
2610 switch (event->priv->instrumentation) {
2611 case LTTNG_KERNEL_ABI_TRACEPOINT:
2612 lttng_fallthrough;
2613 case LTTNG_KERNEL_ABI_SYSCALL:
2614 return true;
2615
2616 default:
2617 /* Not handled with lazy sync. */
2618 return false;
2619 }
2620 }
2621
2622 /*
2623 * Should be called with sessions mutex held.
2624 */
2625 static
2626 void lttng_sync_event_list(struct list_head *event_enabler_list,
2627 struct list_head *event_list)
2628 {
2629 struct lttng_kernel_event_common_private *event_priv;
2630 struct lttng_event_enabler_common *event_enabler;
2631
2632 list_for_each_entry(event_enabler, event_enabler_list, node)
2633 lttng_event_enabler_ref_events(event_enabler);
2634
2635 /*
2636 * For each event, if at least one of its enablers is enabled,
2637 * and its channel and session transient states are enabled, we
2638 * enable the event, else we disable it.
2639 */
2640 list_for_each_entry(event_priv, event_list, node) {
2641 struct lttng_kernel_event_common *event = event_priv->pub;
2642 bool enabled;
2643
2644 if (!lttng_event_is_lazy_sync(event))
2645 continue;
2646
2647 enabled = lttng_get_event_enabled_state(event);
2648 WRITE_ONCE(event->enabled, enabled);
2649 /*
2650 * Sync tracepoint registration with event enabled state.
2651 */
2652 if (enabled) {
2653 if (!event_priv->registered)
2654 register_event(event);
2655 } else {
2656 if (event_priv->registered)
2657 unregister_event(event);
2658 }
2659
2660 lttng_event_sync_filter_state(event);
2661 lttng_event_sync_capture_state(event);
2662 }
2663 }
2664
2665 /*
2666 * lttng_session_sync_event_enablers should be called just before starting a
2667 * session.
2668 */
2669 static
2670 void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2671 {
2672 lttng_sync_event_list(&session->priv->enablers_head, &session->priv->events);
2673 }
2674
2675 /*
2676 * Apply enablers to session events, adding events to session if need
2677 * be. It is required after each modification applied to an active
2678 * session, and right before session "start".
2679 * "lazy" sync means we only sync if required.
2680 * Should be called with sessions mutex held.
2681 */
2682 static
2683 void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2684 {
2685 /* We can skip if session is not active */
2686 if (!session->active)
2687 return;
2688 lttng_session_sync_event_enablers(session);
2689 }
2690
2691 static
2692 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2693 {
2694 lttng_sync_event_list(&event_notifier_group->enablers_head, &event_notifier_group->event_notifiers_head);
2695 }
2696
2697 static
2698 void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler)
2699 {
2700 switch (event_enabler->enabler_type) {
2701 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2702 {
2703 struct lttng_event_recorder_enabler *event_recorder_enabler =
2704 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2705 lttng_session_lazy_sync_event_enablers(event_recorder_enabler->chan->parent.session);
2706 break;
2707 }
2708 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2709 {
2710 struct lttng_event_notifier_enabler *event_notifier_enabler =
2711 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2712 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2713 break;
2714 }
2715 default:
2716 WARN_ON_ONCE(1);
2717 }
2718 }
2719
2720 /*
2721 * Serialize at most one packet worth of metadata into a metadata
2722 * channel.
2723 * We grab the metadata cache mutex to get exclusive access to our metadata
2724 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2725 * allows us to do racy operations such as looking for remaining space left in
2726 * packet and write, since mutual exclusion protects us from concurrent writes.
2727 * Mutual exclusion on the metadata cache allow us to read the cache content
2728 * without racing against reallocation of the cache by updates.
2729 * Returns the number of bytes written in the channel, 0 if no data
2730 * was written and a negative value on error.
2731 */
2732 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2733 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2734 {
2735 struct lttng_kernel_ring_buffer_ctx ctx;
2736 int ret = 0;
2737 size_t len, reserve_len;
2738
2739 /*
2740 * Ensure we support mutiple get_next / put sequences followed by
2741 * put_next. The metadata cache lock protects reading the metadata
2742 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2743 * "flush" operations on the buffer invoked by different processes.
2744 * Moreover, since the metadata cache memory can be reallocated, we
2745 * need to have exclusive access against updates even though we only
2746 * read it.
2747 */
2748 mutex_lock(&stream->metadata_cache->lock);
2749 WARN_ON(stream->metadata_in < stream->metadata_out);
2750 if (stream->metadata_in != stream->metadata_out)
2751 goto end;
2752
2753 /* Metadata regenerated, change the version. */
2754 if (stream->metadata_cache->version != stream->version)
2755 stream->version = stream->metadata_cache->version;
2756
2757 len = stream->metadata_cache->metadata_written -
2758 stream->metadata_in;
2759 if (!len)
2760 goto end;
2761 reserve_len = min_t(size_t,
2762 stream->transport->ops.priv->packet_avail_size(chan),
2763 len);
2764 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2765 sizeof(char), NULL);
2766 /*
2767 * If reservation failed, return an error to the caller.
2768 */
2769 ret = stream->transport->ops.event_reserve(&ctx);
2770 if (ret != 0) {
2771 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2772 stream->coherent = false;
2773 goto end;
2774 }
2775 stream->transport->ops.event_write(&ctx,
2776 stream->metadata_cache->data + stream->metadata_in,
2777 reserve_len, 1);
2778 stream->transport->ops.event_commit(&ctx);
2779 stream->metadata_in += reserve_len;
2780 if (reserve_len < len)
2781 stream->coherent = false;
2782 else
2783 stream->coherent = true;
2784 ret = reserve_len;
2785
2786 end:
2787 if (coherent)
2788 *coherent = stream->coherent;
2789 mutex_unlock(&stream->metadata_cache->lock);
2790 return ret;
2791 }
2792
2793 static
2794 void lttng_metadata_begin(struct lttng_kernel_session *session)
2795 {
2796 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
2797 mutex_lock(&session->priv->metadata_cache->lock);
2798 }
2799
2800 static
2801 void lttng_metadata_end(struct lttng_kernel_session *session)
2802 {
2803 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2804 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
2805 struct lttng_metadata_stream *stream;
2806
2807 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
2808 wake_up_interruptible(&stream->read_wait);
2809 mutex_unlock(&session->priv->metadata_cache->lock);
2810 }
2811 }
2812
2813 /*
2814 * Write the metadata to the metadata cache.
2815 * Must be called with sessions_mutex held.
2816 * The metadata cache lock protects us from concurrent read access from
2817 * thread outputting metadata content to ring buffer.
2818 * The content of the printf is printed as a single atomic metadata
2819 * transaction.
2820 */
2821 int lttng_metadata_printf(struct lttng_kernel_session *session,
2822 const char *fmt, ...)
2823 {
2824 char *str;
2825 size_t len;
2826 va_list ap;
2827
2828 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2829
2830 va_start(ap, fmt);
2831 str = kvasprintf(GFP_KERNEL, fmt, ap);
2832 va_end(ap);
2833 if (!str)
2834 return -ENOMEM;
2835
2836 len = strlen(str);
2837 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2838 if (session->priv->metadata_cache->metadata_written + len >
2839 session->priv->metadata_cache->cache_alloc) {
2840 char *tmp_cache_realloc;
2841 unsigned int tmp_cache_alloc_size;
2842
2843 tmp_cache_alloc_size = max_t(unsigned int,
2844 session->priv->metadata_cache->cache_alloc + len,
2845 session->priv->metadata_cache->cache_alloc << 1);
2846 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2847 if (!tmp_cache_realloc)
2848 goto err;
2849 if (session->priv->metadata_cache->data) {
2850 memcpy(tmp_cache_realloc,
2851 session->priv->metadata_cache->data,
2852 session->priv->metadata_cache->cache_alloc);
2853 vfree(session->priv->metadata_cache->data);
2854 }
2855
2856 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2857 session->priv->metadata_cache->data = tmp_cache_realloc;
2858 }
2859 memcpy(session->priv->metadata_cache->data +
2860 session->priv->metadata_cache->metadata_written,
2861 str, len);
2862 session->priv->metadata_cache->metadata_written += len;
2863 kfree(str);
2864
2865 return 0;
2866
2867 err:
2868 kfree(str);
2869 return -ENOMEM;
2870 }
2871
2872 static
2873 int print_tabs(struct lttng_kernel_session *session, size_t nesting)
2874 {
2875 size_t i;
2876
2877 for (i = 0; i < nesting; i++) {
2878 int ret;
2879
2880 ret = lttng_metadata_printf(session, " ");
2881 if (ret) {
2882 return ret;
2883 }
2884 }
2885 return 0;
2886 }
2887
2888 static
2889 int lttng_field_name_statedump(struct lttng_kernel_session *session,
2890 const struct lttng_kernel_event_field *field,
2891 size_t nesting)
2892 {
2893 return lttng_metadata_printf(session, " _%s;\n", field->name);
2894 }
2895
2896 static
2897 int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
2898 const struct lttng_kernel_type_integer *type,
2899 enum lttng_kernel_string_encoding parent_encoding,
2900 size_t nesting)
2901 {
2902 int ret;
2903
2904 ret = print_tabs(session, nesting);
2905 if (ret)
2906 return ret;
2907 ret = lttng_metadata_printf(session,
2908 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
2909 type->size,
2910 type->alignment,
2911 type->signedness,
2912 (parent_encoding == lttng_kernel_string_encoding_none)
2913 ? "none"
2914 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
2915 ? "UTF8"
2916 : "ASCII",
2917 type->base,
2918 #if __BYTE_ORDER == __BIG_ENDIAN
2919 type->reverse_byte_order ? " byte_order = le;" : ""
2920 #else
2921 type->reverse_byte_order ? " byte_order = be;" : ""
2922 #endif
2923 );
2924 return ret;
2925 }
2926
2927 /*
2928 * Must be called with sessions_mutex held.
2929 */
2930 static
2931 int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
2932 const struct lttng_kernel_type_struct *type,
2933 size_t nesting)
2934 {
2935 const char *prev_field_name = NULL;
2936 int ret;
2937 uint32_t i, nr_fields;
2938 unsigned int alignment;
2939
2940 ret = print_tabs(session, nesting);
2941 if (ret)
2942 return ret;
2943 ret = lttng_metadata_printf(session,
2944 "struct {\n");
2945 if (ret)
2946 return ret;
2947 nr_fields = type->nr_fields;
2948 for (i = 0; i < nr_fields; i++) {
2949 const struct lttng_kernel_event_field *iter_field;
2950
2951 iter_field = type->fields[i];
2952 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
2953 if (ret)
2954 return ret;
2955 }
2956 ret = print_tabs(session, nesting);
2957 if (ret)
2958 return ret;
2959 alignment = type->alignment;
2960 if (alignment) {
2961 ret = lttng_metadata_printf(session,
2962 "} align(%u)",
2963 alignment);
2964 } else {
2965 ret = lttng_metadata_printf(session,
2966 "}");
2967 }
2968 return ret;
2969 }
2970
2971 /*
2972 * Must be called with sessions_mutex held.
2973 */
2974 static
2975 int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
2976 const struct lttng_kernel_event_field *field,
2977 size_t nesting)
2978 {
2979 int ret;
2980
2981 ret = _lttng_struct_type_statedump(session,
2982 lttng_kernel_get_type_struct(field->type), nesting);
2983 if (ret)
2984 return ret;
2985 return lttng_field_name_statedump(session, field, nesting);
2986 }
2987
2988 /*
2989 * Must be called with sessions_mutex held.
2990 */
2991 static
2992 int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
2993 const struct lttng_kernel_type_variant *type,
2994 size_t nesting,
2995 const char *prev_field_name)
2996 {
2997 const char *tag_name;
2998 int ret;
2999 uint32_t i, nr_choices;
3000
3001 tag_name = type->tag_name;
3002 if (!tag_name)
3003 tag_name = prev_field_name;
3004 if (!tag_name)
3005 return -EINVAL;
3006 /*
3007 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3008 */
3009 if (type->alignment != 0)
3010 return -EINVAL;
3011 ret = print_tabs(session, nesting);
3012 if (ret)
3013 return ret;
3014 ret = lttng_metadata_printf(session,
3015 "variant <_%s> {\n",
3016 tag_name);
3017 if (ret)
3018 return ret;
3019 nr_choices = type->nr_choices;
3020 for (i = 0; i < nr_choices; i++) {
3021 const struct lttng_kernel_event_field *iter_field;
3022
3023 iter_field = type->choices[i];
3024 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3025 if (ret)
3026 return ret;
3027 }
3028 ret = print_tabs(session, nesting);
3029 if (ret)
3030 return ret;
3031 ret = lttng_metadata_printf(session,
3032 "}");
3033 return ret;
3034 }
3035
3036 /*
3037 * Must be called with sessions_mutex held.
3038 */
3039 static
3040 int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3041 const struct lttng_kernel_event_field *field,
3042 size_t nesting,
3043 const char *prev_field_name)
3044 {
3045 int ret;
3046
3047 ret = _lttng_variant_type_statedump(session,
3048 lttng_kernel_get_type_variant(field->type), nesting,
3049 prev_field_name);
3050 if (ret)
3051 return ret;
3052 return lttng_field_name_statedump(session, field, nesting);
3053 }
3054
3055 /*
3056 * Must be called with sessions_mutex held.
3057 */
3058 static
3059 int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3060 const struct lttng_kernel_event_field *field,
3061 size_t nesting)
3062 {
3063 int ret;
3064 const struct lttng_kernel_type_array *array_type;
3065 const struct lttng_kernel_type_common *elem_type;
3066
3067 array_type = lttng_kernel_get_type_array(field->type);
3068 WARN_ON_ONCE(!array_type);
3069
3070 if (array_type->alignment) {
3071 ret = print_tabs(session, nesting);
3072 if (ret)
3073 return ret;
3074 ret = lttng_metadata_printf(session,
3075 "struct { } align(%u) _%s_padding;\n",
3076 array_type->alignment * CHAR_BIT,
3077 field->name);
3078 if (ret)
3079 return ret;
3080 }
3081 /*
3082 * Nested compound types: Only array of structures and variants are
3083 * currently supported.
3084 */
3085 elem_type = array_type->elem_type;
3086 switch (elem_type->type) {
3087 case lttng_kernel_type_integer:
3088 case lttng_kernel_type_struct:
3089 case lttng_kernel_type_variant:
3090 ret = _lttng_type_statedump(session, elem_type,
3091 array_type->encoding, nesting);
3092 if (ret)
3093 return ret;
3094 break;
3095
3096 default:
3097 return -EINVAL;
3098 }
3099 ret = lttng_metadata_printf(session,
3100 " _%s[%u];\n",
3101 field->name,
3102 array_type->length);
3103 return ret;
3104 }
3105
3106 /*
3107 * Must be called with sessions_mutex held.
3108 */
3109 static
3110 int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3111 const struct lttng_kernel_event_field *field,
3112 size_t nesting,
3113 const char *prev_field_name)
3114 {
3115 int ret;
3116 const char *length_name;
3117 const struct lttng_kernel_type_sequence *sequence_type;
3118 const struct lttng_kernel_type_common *elem_type;
3119
3120 sequence_type = lttng_kernel_get_type_sequence(field->type);
3121 WARN_ON_ONCE(!sequence_type);
3122
3123 length_name = sequence_type->length_name;
3124 if (!length_name)
3125 length_name = prev_field_name;
3126 if (!length_name)
3127 return -EINVAL;
3128
3129 if (sequence_type->alignment) {
3130 ret = print_tabs(session, nesting);
3131 if (ret)
3132 return ret;
3133 ret = lttng_metadata_printf(session,
3134 "struct { } align(%u) _%s_padding;\n",
3135 sequence_type->alignment * CHAR_BIT,
3136 field->name);
3137 if (ret)
3138 return ret;
3139 }
3140
3141 /*
3142 * Nested compound types: Only array of structures and variants are
3143 * currently supported.
3144 */
3145 elem_type = sequence_type->elem_type;
3146 switch (elem_type->type) {
3147 case lttng_kernel_type_integer:
3148 case lttng_kernel_type_struct:
3149 case lttng_kernel_type_variant:
3150 ret = _lttng_type_statedump(session, elem_type,
3151 sequence_type->encoding, nesting);
3152 if (ret)
3153 return ret;
3154 break;
3155
3156 default:
3157 return -EINVAL;
3158 }
3159 ret = lttng_metadata_printf(session,
3160 " _%s[ _%s ];\n",
3161 field->name,
3162 length_name);
3163 return ret;
3164 }
3165
3166 /*
3167 * Must be called with sessions_mutex held.
3168 */
3169 static
3170 int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3171 const struct lttng_kernel_type_enum *type,
3172 size_t nesting)
3173 {
3174 const struct lttng_kernel_enum_desc *enum_desc;
3175 const struct lttng_kernel_type_common *container_type;
3176 int ret;
3177 unsigned int i, nr_entries;
3178
3179 container_type = type->container_type;
3180 if (container_type->type != lttng_kernel_type_integer) {
3181 ret = -EINVAL;
3182 goto end;
3183 }
3184 enum_desc = type->desc;
3185 nr_entries = enum_desc->nr_entries;
3186
3187 ret = print_tabs(session, nesting);
3188 if (ret)
3189 goto end;
3190 ret = lttng_metadata_printf(session, "enum : ");
3191 if (ret)
3192 goto end;
3193 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3194 lttng_kernel_string_encoding_none, 0);
3195 if (ret)
3196 goto end;
3197 ret = lttng_metadata_printf(session, " {\n");
3198 if (ret)
3199 goto end;
3200 /* Dump all entries */
3201 for (i = 0; i < nr_entries; i++) {
3202 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3203 int j, len;
3204
3205 ret = print_tabs(session, nesting + 1);
3206 if (ret)
3207 goto end;
3208 ret = lttng_metadata_printf(session,
3209 "\"");
3210 if (ret)
3211 goto end;
3212 len = strlen(entry->string);
3213 /* Escape the character '"' */
3214 for (j = 0; j < len; j++) {
3215 char c = entry->string[j];
3216
3217 switch (c) {
3218 case '"':
3219 ret = lttng_metadata_printf(session,
3220 "\\\"");
3221 break;
3222 case '\\':
3223 ret = lttng_metadata_printf(session,
3224 "\\\\");
3225 break;
3226 default:
3227 ret = lttng_metadata_printf(session,
3228 "%c", c);
3229 break;
3230 }
3231 if (ret)
3232 goto end;
3233 }
3234 ret = lttng_metadata_printf(session, "\"");
3235 if (ret)
3236 goto end;
3237
3238 if (entry->options.is_auto) {
3239 ret = lttng_metadata_printf(session, ",\n");
3240 if (ret)
3241 goto end;
3242 } else {
3243 ret = lttng_metadata_printf(session,
3244 " = ");
3245 if (ret)
3246 goto end;
3247 if (entry->start.signedness)
3248 ret = lttng_metadata_printf(session,
3249 "%lld", (long long) entry->start.value);
3250 else
3251 ret = lttng_metadata_printf(session,
3252 "%llu", entry->start.value);
3253 if (ret)
3254 goto end;
3255 if (entry->start.signedness == entry->end.signedness &&
3256 entry->start.value
3257 == entry->end.value) {
3258 ret = lttng_metadata_printf(session,
3259 ",\n");
3260 } else {
3261 if (entry->end.signedness) {
3262 ret = lttng_metadata_printf(session,
3263 " ... %lld,\n",
3264 (long long) entry->end.value);
3265 } else {
3266 ret = lttng_metadata_printf(session,
3267 " ... %llu,\n",
3268 entry->end.value);
3269 }
3270 }
3271 if (ret)
3272 goto end;
3273 }
3274 }
3275 ret = print_tabs(session, nesting);
3276 if (ret)
3277 goto end;
3278 ret = lttng_metadata_printf(session, "}");
3279 end:
3280 return ret;
3281 }
3282
3283 /*
3284 * Must be called with sessions_mutex held.
3285 */
3286 static
3287 int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3288 const struct lttng_kernel_event_field *field,
3289 size_t nesting)
3290 {
3291 int ret;
3292 const struct lttng_kernel_type_enum *enum_type;
3293
3294 enum_type = lttng_kernel_get_type_enum(field->type);
3295 WARN_ON_ONCE(!enum_type);
3296 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3297 if (ret)
3298 return ret;
3299 return lttng_field_name_statedump(session, field, nesting);
3300 }
3301
3302 static
3303 int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3304 const struct lttng_kernel_event_field *field,
3305 size_t nesting)
3306 {
3307 int ret;
3308
3309 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3310 lttng_kernel_string_encoding_none, nesting);
3311 if (ret)
3312 return ret;
3313 return lttng_field_name_statedump(session, field, nesting);
3314 }
3315
3316 static
3317 int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3318 const struct lttng_kernel_type_string *type,
3319 size_t nesting)
3320 {
3321 int ret;
3322
3323 /* Default encoding is UTF8 */
3324 ret = print_tabs(session, nesting);
3325 if (ret)
3326 return ret;
3327 ret = lttng_metadata_printf(session,
3328 "string%s",
3329 type->encoding == lttng_kernel_string_encoding_ASCII ?
3330 " { encoding = ASCII; }" : "");
3331 return ret;
3332 }
3333
3334 static
3335 int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3336 const struct lttng_kernel_event_field *field,
3337 size_t nesting)
3338 {
3339 const struct lttng_kernel_type_string *string_type;
3340 int ret;
3341
3342 string_type = lttng_kernel_get_type_string(field->type);
3343 WARN_ON_ONCE(!string_type);
3344 ret = _lttng_string_type_statedump(session, string_type, nesting);
3345 if (ret)
3346 return ret;
3347 return lttng_field_name_statedump(session, field, nesting);
3348 }
3349
3350 /*
3351 * Must be called with sessions_mutex held.
3352 */
3353 static
3354 int _lttng_type_statedump(struct lttng_kernel_session *session,
3355 const struct lttng_kernel_type_common *type,
3356 enum lttng_kernel_string_encoding parent_encoding,
3357 size_t nesting)
3358 {
3359 int ret = 0;
3360
3361 switch (type->type) {
3362 case lttng_kernel_type_integer:
3363 ret = _lttng_integer_type_statedump(session,
3364 lttng_kernel_get_type_integer(type),
3365 parent_encoding, nesting);
3366 break;
3367 case lttng_kernel_type_enum:
3368 ret = _lttng_enum_type_statedump(session,
3369 lttng_kernel_get_type_enum(type),
3370 nesting);
3371 break;
3372 case lttng_kernel_type_string:
3373 ret = _lttng_string_type_statedump(session,
3374 lttng_kernel_get_type_string(type),
3375 nesting);
3376 break;
3377 case lttng_kernel_type_struct:
3378 ret = _lttng_struct_type_statedump(session,
3379 lttng_kernel_get_type_struct(type),
3380 nesting);
3381 break;
3382 case lttng_kernel_type_variant:
3383 ret = _lttng_variant_type_statedump(session,
3384 lttng_kernel_get_type_variant(type),
3385 nesting, NULL);
3386 break;
3387
3388 /* Nested arrays and sequences are not supported yet. */
3389 case lttng_kernel_type_array:
3390 case lttng_kernel_type_sequence:
3391 default:
3392 WARN_ON_ONCE(1);
3393 return -EINVAL;
3394 }
3395 return ret;
3396 }
3397
3398 /*
3399 * Must be called with sessions_mutex held.
3400 */
3401 static
3402 int _lttng_field_statedump(struct lttng_kernel_session *session,
3403 const struct lttng_kernel_event_field *field,
3404 size_t nesting,
3405 const char **prev_field_name_p)
3406 {
3407 const char *prev_field_name = NULL;
3408 int ret = 0;
3409
3410 if (prev_field_name_p)
3411 prev_field_name = *prev_field_name_p;
3412 switch (field->type->type) {
3413 case lttng_kernel_type_integer:
3414 ret = _lttng_integer_field_statedump(session, field, nesting);
3415 break;
3416 case lttng_kernel_type_enum:
3417 ret = _lttng_enum_field_statedump(session, field, nesting);
3418 break;
3419 case lttng_kernel_type_string:
3420 ret = _lttng_string_field_statedump(session, field, nesting);
3421 break;
3422 case lttng_kernel_type_struct:
3423 ret = _lttng_struct_field_statedump(session, field, nesting);
3424 break;
3425 case lttng_kernel_type_array:
3426 ret = _lttng_array_field_statedump(session, field, nesting);
3427 break;
3428 case lttng_kernel_type_sequence:
3429 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3430 break;
3431 case lttng_kernel_type_variant:
3432 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3433 break;
3434
3435 default:
3436 WARN_ON_ONCE(1);
3437 return -EINVAL;
3438 }
3439 if (prev_field_name_p)
3440 *prev_field_name_p = field->name;
3441 return ret;
3442 }
3443
3444 static
3445 int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3446 struct lttng_kernel_ctx *ctx)
3447 {
3448 const char *prev_field_name = NULL;
3449 int ret = 0;
3450 int i;
3451
3452 if (!ctx)
3453 return 0;
3454 for (i = 0; i < ctx->nr_fields; i++) {
3455 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3456
3457 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3458 if (ret)
3459 return ret;
3460 }
3461 return ret;
3462 }
3463
3464 static
3465 int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3466 struct lttng_kernel_event_recorder *event_recorder)
3467 {
3468 const char *prev_field_name = NULL;
3469 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3470 int ret = 0;
3471 int i;
3472
3473 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3474 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3475
3476 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3477 if (ret)
3478 return ret;
3479 }
3480 return ret;
3481 }
3482
3483 /*
3484 * Must be called with sessions_mutex held.
3485 * The entire event metadata is printed as a single atomic metadata
3486 * transaction.
3487 */
3488 static
3489 int _lttng_event_recorder_metadata_statedump(struct lttng_kernel_event_common *event)
3490 {
3491 struct lttng_kernel_event_recorder *event_recorder;
3492 struct lttng_kernel_channel_buffer *chan;
3493 struct lttng_kernel_session *session;
3494 int ret = 0;
3495
3496 if (event->type != LTTNG_KERNEL_EVENT_TYPE_RECORDER)
3497 return 0;
3498 event_recorder = container_of(event, struct lttng_kernel_event_recorder, parent);
3499 chan = event_recorder->chan;
3500 session = chan->parent.session;
3501
3502 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3503 return 0;
3504 if (chan->priv->channel_type == METADATA_CHANNEL)
3505 return 0;
3506
3507 lttng_metadata_begin(session);
3508
3509 ret = lttng_metadata_printf(session,
3510 "event {\n"
3511 " name = \"%s\";\n"
3512 " id = %u;\n"
3513 " stream_id = %u;\n",
3514 event_recorder->priv->parent.desc->event_name,
3515 event_recorder->priv->id,
3516 event_recorder->chan->priv->id);
3517 if (ret)
3518 goto end;
3519
3520 ret = lttng_metadata_printf(session,
3521 " fields := struct {\n"
3522 );
3523 if (ret)
3524 goto end;
3525
3526 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3527 if (ret)
3528 goto end;
3529
3530 /*
3531 * LTTng space reservation can only reserve multiples of the
3532 * byte size.
3533 */
3534 ret = lttng_metadata_printf(session,
3535 " };\n"
3536 "};\n\n");
3537 if (ret)
3538 goto end;
3539
3540 event_recorder->priv->metadata_dumped = 1;
3541 end:
3542 lttng_metadata_end(session);
3543 return ret;
3544
3545 }
3546
3547 /*
3548 * Must be called with sessions_mutex held.
3549 * The entire channel metadata is printed as a single atomic metadata
3550 * transaction.
3551 */
3552 static
3553 int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3554 struct lttng_kernel_channel_buffer *chan)
3555 {
3556 int ret = 0;
3557
3558 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3559 return 0;
3560
3561 if (chan->priv->channel_type == METADATA_CHANNEL)
3562 return 0;
3563
3564 lttng_metadata_begin(session);
3565
3566 WARN_ON_ONCE(!chan->priv->header_type);
3567 ret = lttng_metadata_printf(session,
3568 "stream {\n"
3569 " id = %u;\n"
3570 " event.header := %s;\n"
3571 " packet.context := struct packet_context;\n",
3572 chan->priv->id,
3573 chan->priv->header_type == 1 ? "struct event_header_compact" :
3574 "struct event_header_large");
3575 if (ret)
3576 goto end;
3577
3578 if (chan->priv->ctx) {
3579 ret = lttng_metadata_printf(session,
3580 " event.context := struct {\n");
3581 if (ret)
3582 goto end;
3583 }
3584 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3585 if (ret)
3586 goto end;
3587 if (chan->priv->ctx) {
3588 ret = lttng_metadata_printf(session,
3589 " };\n");
3590 if (ret)
3591 goto end;
3592 }
3593
3594 ret = lttng_metadata_printf(session,
3595 "};\n\n");
3596
3597 chan->priv->metadata_dumped = 1;
3598 end:
3599 lttng_metadata_end(session);
3600 return ret;
3601 }
3602
3603 /*
3604 * Must be called with sessions_mutex held.
3605 */
3606 static
3607 int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3608 {
3609 return lttng_metadata_printf(session,
3610 "struct packet_context {\n"
3611 " uint64_clock_monotonic_t timestamp_begin;\n"
3612 " uint64_clock_monotonic_t timestamp_end;\n"
3613 " uint64_t content_size;\n"
3614 " uint64_t packet_size;\n"
3615 " uint64_t packet_seq_num;\n"
3616 " unsigned long events_discarded;\n"
3617 " uint32_t cpu_id;\n"
3618 "};\n\n"
3619 );
3620 }
3621
3622 /*
3623 * Compact header:
3624 * id: range: 0 - 30.
3625 * id 31 is reserved to indicate an extended header.
3626 *
3627 * Large header:
3628 * id: range: 0 - 65534.
3629 * id 65535 is reserved to indicate an extended header.
3630 *
3631 * Must be called with sessions_mutex held.
3632 */
3633 static
3634 int _lttng_event_header_declare(struct lttng_kernel_session *session)
3635 {
3636 return lttng_metadata_printf(session,
3637 "struct event_header_compact {\n"
3638 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3639 " variant <id> {\n"
3640 " struct {\n"
3641 " uint27_clock_monotonic_t timestamp;\n"
3642 " } compact;\n"
3643 " struct {\n"
3644 " uint32_t id;\n"
3645 " uint64_clock_monotonic_t timestamp;\n"
3646 " } extended;\n"
3647 " } v;\n"
3648 "} align(%u);\n"
3649 "\n"
3650 "struct event_header_large {\n"
3651 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3652 " variant <id> {\n"
3653 " struct {\n"
3654 " uint32_clock_monotonic_t timestamp;\n"
3655 " } compact;\n"
3656 " struct {\n"
3657 " uint32_t id;\n"
3658 " uint64_clock_monotonic_t timestamp;\n"
3659 " } extended;\n"
3660 " } v;\n"
3661 "} align(%u);\n\n",
3662 lttng_alignof(uint32_t) * CHAR_BIT,
3663 lttng_alignof(uint16_t) * CHAR_BIT
3664 );
3665 }
3666
3667 /*
3668 * Approximation of NTP time of day to clock monotonic correlation,
3669 * taken at start of trace.
3670 * Yes, this is only an approximation. Yes, we can (and will) do better
3671 * in future versions.
3672 * This function may return a negative offset. It may happen if the
3673 * system sets the REALTIME clock to 0 after boot.
3674 *
3675 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3676 * y2038 compliant.
3677 */
3678 static
3679 int64_t measure_clock_offset(void)
3680 {
3681 uint64_t monotonic_avg, monotonic[2], realtime;
3682 uint64_t tcf = trace_clock_freq();
3683 int64_t offset;
3684 unsigned long flags;
3685 struct timespec64 rts = { 0, 0 };
3686
3687 /* Disable interrupts to increase correlation precision. */
3688 local_irq_save(flags);
3689 monotonic[0] = trace_clock_read64();
3690 ktime_get_real_ts64(&rts);
3691 monotonic[1] = trace_clock_read64();
3692 local_irq_restore(flags);
3693
3694 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3695 realtime = (uint64_t) rts.tv_sec * tcf;
3696 if (tcf == NSEC_PER_SEC) {
3697 realtime += rts.tv_nsec;
3698 } else {
3699 uint64_t n = rts.tv_nsec * tcf;
3700
3701 do_div(n, NSEC_PER_SEC);
3702 realtime += n;
3703 }
3704 offset = (int64_t) realtime - monotonic_avg;
3705 return offset;
3706 }
3707
3708 static
3709 int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3710 {
3711 int ret = 0;
3712 size_t i;
3713 char cur;
3714
3715 i = 0;
3716 cur = string[i];
3717 while (cur != '\0') {
3718 switch (cur) {
3719 case '\n':
3720 ret = lttng_metadata_printf(session, "%s", "\\n");
3721 break;
3722 case '\\':
3723 case '"':
3724 ret = lttng_metadata_printf(session, "%c", '\\');
3725 if (ret)
3726 goto error;
3727 /* We still print the current char */
3728 lttng_fallthrough;
3729 default:
3730 ret = lttng_metadata_printf(session, "%c", cur);
3731 break;
3732 }
3733
3734 if (ret)
3735 goto error;
3736
3737 cur = string[++i];
3738 }
3739 error:
3740 return ret;
3741 }
3742
3743 static
3744 int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3745 const char *field_value)
3746 {
3747 int ret;
3748
3749 ret = lttng_metadata_printf(session, " %s = \"", field);
3750 if (ret)
3751 goto error;
3752
3753 ret = print_escaped_ctf_string(session, field_value);
3754 if (ret)
3755 goto error;
3756
3757 ret = lttng_metadata_printf(session, "\";\n");
3758
3759 error:
3760 return ret;
3761 }
3762
3763 /*
3764 * Output metadata into this session's metadata buffers.
3765 * Must be called with sessions_mutex held.
3766 */
3767 static
3768 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3769 {
3770 unsigned char *uuid_c = session->priv->uuid.b;
3771 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3772 const char *product_uuid;
3773 struct lttng_kernel_channel_buffer_private *chan_priv;
3774 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3775 int ret = 0;
3776
3777 if (!LTTNG_READ_ONCE(session->active))
3778 return 0;
3779
3780 lttng_metadata_begin(session);
3781
3782 if (session->priv->metadata_dumped)
3783 goto skip_session;
3784
3785 snprintf(uuid_s, sizeof(uuid_s),
3786 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3787 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3788 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3789 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3790 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3791
3792 ret = lttng_metadata_printf(session,
3793 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3794 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3795 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3796 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3797 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3798 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3799 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3800 "\n"
3801 "trace {\n"
3802 " major = %u;\n"
3803 " minor = %u;\n"
3804 " uuid = \"%s\";\n"
3805 " byte_order = %s;\n"
3806 " packet.header := struct {\n"
3807 " uint32_t magic;\n"
3808 " uint8_t uuid[16];\n"
3809 " uint32_t stream_id;\n"
3810 " uint64_t stream_instance_id;\n"
3811 " };\n"
3812 "};\n\n",
3813 lttng_alignof(uint8_t) * CHAR_BIT,
3814 lttng_alignof(uint16_t) * CHAR_BIT,
3815 lttng_alignof(uint32_t) * CHAR_BIT,
3816 lttng_alignof(uint64_t) * CHAR_BIT,
3817 sizeof(unsigned long) * CHAR_BIT,
3818 lttng_alignof(unsigned long) * CHAR_BIT,
3819 CTF_SPEC_MAJOR,
3820 CTF_SPEC_MINOR,
3821 uuid_s,
3822 #if __BYTE_ORDER == __BIG_ENDIAN
3823 "be"
3824 #else
3825 "le"
3826 #endif
3827 );
3828 if (ret)
3829 goto end;
3830
3831 ret = lttng_metadata_printf(session,
3832 "env {\n"
3833 " hostname = \"%s\";\n"
3834 " domain = \"kernel\";\n"
3835 " sysname = \"%s\";\n"
3836 " kernel_release = \"%s\";\n"
3837 " kernel_version = \"%s\";\n"
3838 " tracer_name = \"lttng-modules\";\n"
3839 " tracer_major = %d;\n"
3840 " tracer_minor = %d;\n"
3841 " tracer_patchlevel = %d;\n"
3842 " trace_buffering_scheme = \"global\";\n",
3843 current->nsproxy->uts_ns->name.nodename,
3844 utsname()->sysname,
3845 utsname()->release,
3846 utsname()->version,
3847 LTTNG_MODULES_MAJOR_VERSION,
3848 LTTNG_MODULES_MINOR_VERSION,
3849 LTTNG_MODULES_PATCHLEVEL_VERSION
3850 );
3851 if (ret)
3852 goto end;
3853
3854 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
3855 if (ret)
3856 goto end;
3857 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3858 session->priv->creation_time);
3859 if (ret)
3860 goto end;
3861
3862 /* Add the product UUID to the 'env' section */
3863 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3864 if (product_uuid) {
3865 ret = lttng_metadata_printf(session,
3866 " product_uuid = \"%s\";\n",
3867 product_uuid
3868 );
3869 if (ret)
3870 goto end;
3871 }
3872
3873 /* Close the 'env' section */
3874 ret = lttng_metadata_printf(session, "};\n\n");
3875 if (ret)
3876 goto end;
3877
3878 ret = lttng_metadata_printf(session,
3879 "clock {\n"
3880 " name = \"%s\";\n",
3881 trace_clock_name()
3882 );
3883 if (ret)
3884 goto end;
3885
3886 if (!trace_clock_uuid(clock_uuid_s)) {
3887 ret = lttng_metadata_printf(session,
3888 " uuid = \"%s\";\n",
3889 clock_uuid_s
3890 );
3891 if (ret)
3892 goto end;
3893 }
3894
3895 ret = lttng_metadata_printf(session,
3896 " description = \"%s\";\n"
3897 " freq = %llu; /* Frequency, in Hz */\n"
3898 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
3899 " offset = %lld;\n"
3900 "};\n\n",
3901 trace_clock_description(),
3902 (unsigned long long) trace_clock_freq(),
3903 (long long) measure_clock_offset()
3904 );
3905 if (ret)
3906 goto end;
3907
3908 ret = lttng_metadata_printf(session,
3909 "typealias integer {\n"
3910 " size = 27; align = 1; signed = false;\n"
3911 " map = clock.%s.value;\n"
3912 "} := uint27_clock_monotonic_t;\n"
3913 "\n"
3914 "typealias integer {\n"
3915 " size = 32; align = %u; signed = false;\n"
3916 " map = clock.%s.value;\n"
3917 "} := uint32_clock_monotonic_t;\n"
3918 "\n"
3919 "typealias integer {\n"
3920 " size = 64; align = %u; signed = false;\n"
3921 " map = clock.%s.value;\n"
3922 "} := uint64_clock_monotonic_t;\n\n",
3923 trace_clock_name(),
3924 lttng_alignof(uint32_t) * CHAR_BIT,
3925 trace_clock_name(),
3926 lttng_alignof(uint64_t) * CHAR_BIT,
3927 trace_clock_name()
3928 );
3929 if (ret)
3930 goto end;
3931
3932 ret = _lttng_stream_packet_context_declare(session);
3933 if (ret)
3934 goto end;
3935
3936 ret = _lttng_event_header_declare(session);
3937 if (ret)
3938 goto end;
3939
3940 skip_session:
3941 list_for_each_entry(chan_priv, &session->priv->chan, node) {
3942 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
3943 if (ret)
3944 goto end;
3945 }
3946
3947 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
3948 ret = _lttng_event_recorder_metadata_statedump(&event_recorder_priv->pub->parent);
3949 if (ret)
3950 goto end;
3951 }
3952 session->priv->metadata_dumped = 1;
3953 end:
3954 lttng_metadata_end(session);
3955 return ret;
3956 }
3957
3958 /**
3959 * lttng_transport_register - LTT transport registration
3960 * @transport: transport structure
3961 *
3962 * Registers a transport which can be used as output to extract the data out of
3963 * LTTng. The module calling this registration function must ensure that no
3964 * trap-inducing code will be executed by the transport functions. E.g.
3965 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
3966 * is made visible to the transport function. This registration acts as a
3967 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
3968 * after its registration must it synchronize the TLBs.
3969 */
3970 void lttng_transport_register(struct lttng_transport *transport)
3971 {
3972 /*
3973 * Make sure no page fault can be triggered by the module about to be
3974 * registered. We deal with this here so we don't have to call
3975 * vmalloc_sync_mappings() in each module's init.
3976 */
3977 wrapper_vmalloc_sync_mappings();
3978
3979 mutex_lock(&sessions_mutex);
3980 list_add_tail(&transport->node, &lttng_transport_list);
3981 mutex_unlock(&sessions_mutex);
3982 }
3983 EXPORT_SYMBOL_GPL(lttng_transport_register);
3984
3985 /**
3986 * lttng_transport_unregister - LTT transport unregistration
3987 * @transport: transport structure
3988 */
3989 void lttng_transport_unregister(struct lttng_transport *transport)
3990 {
3991 mutex_lock(&sessions_mutex);
3992 list_del(&transport->node);
3993 mutex_unlock(&sessions_mutex);
3994 }
3995 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
3996
3997 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
3998 {
3999 /*
4000 * Make sure no page fault can be triggered by the module about to be
4001 * registered. We deal with this here so we don't have to call
4002 * vmalloc_sync_mappings() in each module's init.
4003 */
4004 wrapper_vmalloc_sync_mappings();
4005
4006 mutex_lock(&sessions_mutex);
4007 list_add_tail(&transport->node, &lttng_counter_transport_list);
4008 mutex_unlock(&sessions_mutex);
4009 }
4010 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4011
4012 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4013 {
4014 mutex_lock(&sessions_mutex);
4015 list_del(&transport->node);
4016 mutex_unlock(&sessions_mutex);
4017 }
4018 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4019
4020 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4021
4022 enum cpuhp_state lttng_hp_prepare;
4023 enum cpuhp_state lttng_hp_online;
4024
4025 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4026 {
4027 struct lttng_cpuhp_node *lttng_node;
4028
4029 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4030 switch (lttng_node->component) {
4031 case LTTNG_RING_BUFFER_FRONTEND:
4032 return 0;
4033 case LTTNG_RING_BUFFER_BACKEND:
4034 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4035 case LTTNG_RING_BUFFER_ITER:
4036 return 0;
4037 case LTTNG_CONTEXT_PERF_COUNTERS:
4038 return 0;
4039 default:
4040 return -EINVAL;
4041 }
4042 }
4043
4044 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4045 {
4046 struct lttng_cpuhp_node *lttng_node;
4047
4048 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4049 switch (lttng_node->component) {
4050 case LTTNG_RING_BUFFER_FRONTEND:
4051 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4052 case LTTNG_RING_BUFFER_BACKEND:
4053 return 0;
4054 case LTTNG_RING_BUFFER_ITER:
4055 return 0;
4056 case LTTNG_CONTEXT_PERF_COUNTERS:
4057 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4058 default:
4059 return -EINVAL;
4060 }
4061 }
4062
4063 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4064 {
4065 struct lttng_cpuhp_node *lttng_node;
4066
4067 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4068 switch (lttng_node->component) {
4069 case LTTNG_RING_BUFFER_FRONTEND:
4070 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4071 case LTTNG_RING_BUFFER_BACKEND:
4072 return 0;
4073 case LTTNG_RING_BUFFER_ITER:
4074 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4075 case LTTNG_CONTEXT_PERF_COUNTERS:
4076 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4077 default:
4078 return -EINVAL;
4079 }
4080 }
4081
4082 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4083 {
4084 struct lttng_cpuhp_node *lttng_node;
4085
4086 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4087 switch (lttng_node->component) {
4088 case LTTNG_RING_BUFFER_FRONTEND:
4089 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4090 case LTTNG_RING_BUFFER_BACKEND:
4091 return 0;
4092 case LTTNG_RING_BUFFER_ITER:
4093 return 0;
4094 case LTTNG_CONTEXT_PERF_COUNTERS:
4095 return 0;
4096 default:
4097 return -EINVAL;
4098 }
4099 }
4100
4101 static int __init lttng_init_cpu_hotplug(void)
4102 {
4103 int ret;
4104
4105 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4106 lttng_hotplug_prepare,
4107 lttng_hotplug_dead);
4108 if (ret < 0) {
4109 return ret;
4110 }
4111 lttng_hp_prepare = ret;
4112 lttng_rb_set_hp_prepare(ret);
4113
4114 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4115 lttng_hotplug_online,
4116 lttng_hotplug_offline);
4117 if (ret < 0) {
4118 cpuhp_remove_multi_state(lttng_hp_prepare);
4119 lttng_hp_prepare = 0;
4120 return ret;
4121 }
4122 lttng_hp_online = ret;
4123 lttng_rb_set_hp_online(ret);
4124
4125 return 0;
4126 }
4127
4128 static void __exit lttng_exit_cpu_hotplug(void)
4129 {
4130 lttng_rb_set_hp_online(0);
4131 cpuhp_remove_multi_state(lttng_hp_online);
4132 lttng_rb_set_hp_prepare(0);
4133 cpuhp_remove_multi_state(lttng_hp_prepare);
4134 }
4135
4136 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4137 static int lttng_init_cpu_hotplug(void)
4138 {
4139 return 0;
4140 }
4141 static void lttng_exit_cpu_hotplug(void)
4142 {
4143 }
4144 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4145
4146 static int __init lttng_events_init(void)
4147 {
4148 int ret;
4149
4150 ret = wrapper_get_pfnblock_flags_mask_init();
4151 if (ret)
4152 return ret;
4153 ret = lttng_probes_init();
4154 if (ret)
4155 return ret;
4156 ret = lttng_context_init();
4157 if (ret)
4158 return ret;
4159 ret = lttng_tracepoint_init();
4160 if (ret)
4161 goto error_tp;
4162 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4163 if (!event_recorder_cache) {
4164 ret = -ENOMEM;
4165 goto error_kmem_event_recorder;
4166 }
4167 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4168 if (!event_recorder_private_cache) {
4169 ret = -ENOMEM;
4170 goto error_kmem_event_recorder_private;
4171 }
4172 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4173 if (!event_notifier_cache) {
4174 ret = -ENOMEM;
4175 goto error_kmem_event_notifier;
4176 }
4177 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4178 if (!event_notifier_private_cache) {
4179 ret = -ENOMEM;
4180 goto error_kmem_event_notifier_private;
4181 }
4182 ret = lttng_abi_init();
4183 if (ret)
4184 goto error_abi;
4185 ret = lttng_logger_init();
4186 if (ret)
4187 goto error_logger;
4188 ret = lttng_init_cpu_hotplug();
4189 if (ret)
4190 goto error_hotplug;
4191 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4192 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4193 __stringify(LTTNG_MODULES_MINOR_VERSION),
4194 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4195 LTTNG_MODULES_EXTRAVERSION,
4196 LTTNG_VERSION_NAME,
4197 #ifdef LTTNG_EXTRA_VERSION_GIT
4198 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4199 #else
4200 "",
4201 #endif
4202 #ifdef LTTNG_EXTRA_VERSION_NAME
4203 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4204 #else
4205 "");
4206 #endif
4207 #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
4208 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
4209 #endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
4210 return 0;
4211
4212 error_hotplug:
4213 lttng_logger_exit();
4214 error_logger:
4215 lttng_abi_exit();
4216 error_abi:
4217 kmem_cache_destroy(event_notifier_private_cache);
4218 error_kmem_event_notifier_private:
4219 kmem_cache_destroy(event_notifier_cache);
4220 error_kmem_event_notifier:
4221 kmem_cache_destroy(event_recorder_private_cache);
4222 error_kmem_event_recorder_private:
4223 kmem_cache_destroy(event_recorder_cache);
4224 error_kmem_event_recorder:
4225 lttng_tracepoint_exit();
4226 error_tp:
4227 lttng_context_exit();
4228 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4229 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4230 __stringify(LTTNG_MODULES_MINOR_VERSION),
4231 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4232 LTTNG_MODULES_EXTRAVERSION,
4233 LTTNG_VERSION_NAME,
4234 #ifdef LTTNG_EXTRA_VERSION_GIT
4235 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4236 #else
4237 "",
4238 #endif
4239 #ifdef LTTNG_EXTRA_VERSION_NAME
4240 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4241 #else
4242 "");
4243 #endif
4244 return ret;
4245 }
4246
4247 module_init(lttng_events_init);
4248
4249 static void __exit lttng_events_exit(void)
4250 {
4251 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4252
4253 lttng_exit_cpu_hotplug();
4254 lttng_logger_exit();
4255 lttng_abi_exit();
4256 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4257 lttng_session_destroy(session_priv->pub);
4258 kmem_cache_destroy(event_recorder_cache);
4259 kmem_cache_destroy(event_recorder_private_cache);
4260 kmem_cache_destroy(event_notifier_cache);
4261 kmem_cache_destroy(event_notifier_private_cache);
4262 lttng_tracepoint_exit();
4263 lttng_context_exit();
4264 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4265 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4266 __stringify(LTTNG_MODULES_MINOR_VERSION),
4267 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4268 LTTNG_MODULES_EXTRAVERSION,
4269 LTTNG_VERSION_NAME,
4270 #ifdef LTTNG_EXTRA_VERSION_GIT
4271 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4272 #else
4273 "",
4274 #endif
4275 #ifdef LTTNG_EXTRA_VERSION_NAME
4276 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4277 #else
4278 "");
4279 #endif
4280 }
4281
4282 module_exit(lttng_events_exit);
4283
4284 #include <generated/patches.h>
4285 #ifdef LTTNG_EXTRA_VERSION_GIT
4286 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4287 #endif
4288 #ifdef LTTNG_EXTRA_VERSION_NAME
4289 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4290 #endif
4291 MODULE_LICENSE("GPL and additional rights");
4292 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4293 MODULE_DESCRIPTION("LTTng tracer");
4294 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4295 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4296 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4297 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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