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fix: isystem: delete global -isystem compile option (v5.16)
[lttng-modules.git] / src / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
2 *
3 * lttng-events.c
4 *
5 * Holds LTTng per-session event registry.
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10 /*
11 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
12 * overrides a function with a define.
13 */
14 #include "wrapper/page_alloc.h"
15
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/jiffies.h>
21 #include <linux/utsname.h>
22 #include <linux/err.h>
23 #include <linux/seq_file.h>
24 #include <linux/file.h>
25 #include <linux/anon_inodes.h>
26 #include <wrapper/file.h>
27 #include <linux/uaccess.h>
28 #include <linux/vmalloc.h>
29 #include <linux/dmi.h>
30
31 #include <wrapper/compiler_attributes.h>
32 #include <wrapper/uuid.h>
33 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
34 #include <wrapper/random.h>
35 #include <wrapper/tracepoint.h>
36 #include <wrapper/list.h>
37 #include <wrapper/types.h>
38 #include <lttng/kernel-version.h>
39 #include <lttng/events.h>
40 #include <lttng/events-internal.h>
41 #include <lttng/lttng-bytecode.h>
42 #include <lttng/tracer.h>
43 #include <lttng/event-notifier-notification.h>
44 #include <lttng/abi-old.h>
45 #include <lttng/endian.h>
46 #include <lttng/string-utils.h>
47 #include <lttng/utils.h>
48 #include <ringbuffer/backend.h>
49 #include <ringbuffer/frontend.h>
50 #include <wrapper/time.h>
51
52 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,16,0))
53 #include <linux/stdarg.h>
54 #else
55 #include <stdarg.h>
56 #endif
57
58 #define METADATA_CACHE_DEFAULT_SIZE 4096
59
60 static LIST_HEAD(sessions);
61 static LIST_HEAD(event_notifier_groups);
62 static LIST_HEAD(lttng_transport_list);
63 static LIST_HEAD(lttng_counter_transport_list);
64 /*
65 * Protect the sessions and metadata caches.
66 */
67 static DEFINE_MUTEX(sessions_mutex);
68 static struct kmem_cache *event_recorder_cache;
69 static struct kmem_cache *event_recorder_private_cache;
70 static struct kmem_cache *event_notifier_cache;
71 static struct kmem_cache *event_notifier_private_cache;
72
73 static void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session);
74 static void lttng_session_sync_event_enablers(struct lttng_kernel_session *session);
75 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
76 static void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler);
77
78 static void _lttng_event_destroy(struct lttng_kernel_event_common *event);
79 static void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan);
80 static void _lttng_event_unregister(struct lttng_kernel_event_common *event);
81 static
82 int _lttng_event_recorder_metadata_statedump(struct lttng_kernel_event_common *event);
83 static
84 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session);
85 static
86 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
87 static
88 int _lttng_type_statedump(struct lttng_kernel_session *session,
89 const struct lttng_kernel_type_common *type,
90 enum lttng_kernel_string_encoding parent_encoding,
91 size_t nesting);
92 static
93 int _lttng_field_statedump(struct lttng_kernel_session *session,
94 const struct lttng_kernel_event_field *field,
95 size_t nesting, const char **prev_field_name_p);
96
97 void synchronize_trace(void)
98 {
99 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0) || \
100 LTTNG_RHEL_KERNEL_RANGE(4,18,0,193,0,0, 4,19,0,0,0,0))
101 synchronize_rcu();
102 #else
103 synchronize_sched();
104 #endif
105
106 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
107 #ifdef CONFIG_PREEMPT_RT_FULL
108 synchronize_rcu();
109 #endif
110 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
111 #ifdef CONFIG_PREEMPT_RT
112 synchronize_rcu();
113 #endif
114 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
115 }
116
117 void lttng_lock_sessions(void)
118 {
119 mutex_lock(&sessions_mutex);
120 }
121
122 void lttng_unlock_sessions(void)
123 {
124 mutex_unlock(&sessions_mutex);
125 }
126
127 static struct lttng_transport *lttng_transport_find(const char *name)
128 {
129 struct lttng_transport *transport;
130
131 list_for_each_entry(transport, &lttng_transport_list, node) {
132 if (!strcmp(transport->name, name))
133 return transport;
134 }
135 return NULL;
136 }
137
138 /*
139 * Called with sessions lock held.
140 */
141 int lttng_session_active(void)
142 {
143 struct lttng_kernel_session_private *iter;
144
145 list_for_each_entry(iter, &sessions, list) {
146 if (iter->pub->active)
147 return 1;
148 }
149 return 0;
150 }
151
152 struct lttng_kernel_session *lttng_session_create(void)
153 {
154 struct lttng_kernel_session *session;
155 struct lttng_kernel_session_private *session_priv;
156 struct lttng_metadata_cache *metadata_cache;
157 int i;
158
159 mutex_lock(&sessions_mutex);
160 session = lttng_kvzalloc(sizeof(*session), GFP_KERNEL);
161 if (!session)
162 goto err;
163 session_priv = lttng_kvzalloc(sizeof(*session_priv), GFP_KERNEL);
164 if (!session_priv)
165 goto err_free_session;
166 session->priv = session_priv;
167 session_priv->pub = session;
168
169 INIT_LIST_HEAD(&session_priv->chan);
170 INIT_LIST_HEAD(&session_priv->events);
171 lttng_guid_gen(&session_priv->uuid);
172
173 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
174 GFP_KERNEL);
175 if (!metadata_cache)
176 goto err_free_session_private;
177 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
178 if (!metadata_cache->data)
179 goto err_free_cache;
180 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
181 kref_init(&metadata_cache->refcount);
182 mutex_init(&metadata_cache->lock);
183 session_priv->metadata_cache = metadata_cache;
184 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
185 memcpy(&metadata_cache->uuid, &session_priv->uuid,
186 sizeof(metadata_cache->uuid));
187 INIT_LIST_HEAD(&session_priv->enablers_head);
188 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
189 INIT_HLIST_HEAD(&session_priv->events_ht.table[i]);
190 list_add(&session_priv->list, &sessions);
191
192 if (lttng_id_tracker_init(&session->pid_tracker, session, TRACKER_PID))
193 goto tracker_alloc_error;
194 if (lttng_id_tracker_init(&session->vpid_tracker, session, TRACKER_VPID))
195 goto tracker_alloc_error;
196 if (lttng_id_tracker_init(&session->uid_tracker, session, TRACKER_UID))
197 goto tracker_alloc_error;
198 if (lttng_id_tracker_init(&session->vuid_tracker, session, TRACKER_VUID))
199 goto tracker_alloc_error;
200 if (lttng_id_tracker_init(&session->gid_tracker, session, TRACKER_GID))
201 goto tracker_alloc_error;
202 if (lttng_id_tracker_init(&session->vgid_tracker, session, TRACKER_VGID))
203 goto tracker_alloc_error;
204
205 mutex_unlock(&sessions_mutex);
206
207 return session;
208
209 tracker_alloc_error:
210 lttng_id_tracker_fini(&session->pid_tracker);
211 lttng_id_tracker_fini(&session->vpid_tracker);
212 lttng_id_tracker_fini(&session->uid_tracker);
213 lttng_id_tracker_fini(&session->vuid_tracker);
214 lttng_id_tracker_fini(&session->gid_tracker);
215 lttng_id_tracker_fini(&session->vgid_tracker);
216 err_free_cache:
217 kfree(metadata_cache);
218 err_free_session_private:
219 lttng_kvfree(session_priv);
220 err_free_session:
221 lttng_kvfree(session);
222 err:
223 mutex_unlock(&sessions_mutex);
224 return NULL;
225 }
226
227 static
228 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
229 {
230 struct lttng_counter_transport *transport;
231
232 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
233 if (!strcmp(transport->name, name))
234 return transport;
235 }
236 return NULL;
237 }
238
239 struct lttng_counter *lttng_kernel_counter_create(
240 const char *counter_transport_name,
241 size_t number_dimensions, const size_t *dimensions_sizes)
242 {
243 struct lttng_counter *counter = NULL;
244 struct lttng_counter_transport *counter_transport = NULL;
245
246 counter_transport = lttng_counter_transport_find(counter_transport_name);
247 if (!counter_transport) {
248 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
249 counter_transport_name);
250 goto notransport;
251 }
252 if (!try_module_get(counter_transport->owner)) {
253 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
254 goto notransport;
255 }
256
257 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
258 if (!counter)
259 goto nomem;
260
261 /* Create event notifier error counter. */
262 counter->ops = &counter_transport->ops;
263 counter->transport = counter_transport;
264
265 counter->counter = counter->ops->counter_create(
266 number_dimensions, dimensions_sizes, 0);
267 if (!counter->counter) {
268 goto create_error;
269 }
270
271 return counter;
272
273 create_error:
274 lttng_kvfree(counter);
275 nomem:
276 if (counter_transport)
277 module_put(counter_transport->owner);
278 notransport:
279 return NULL;
280 }
281
282 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
283 {
284 struct lttng_transport *transport = NULL;
285 struct lttng_event_notifier_group *event_notifier_group;
286 const char *transport_name = "relay-event-notifier";
287 size_t subbuf_size = 4096; //TODO
288 size_t num_subbuf = 16; //TODO
289 unsigned int switch_timer_interval = 0;
290 unsigned int read_timer_interval = 0;
291 int i;
292
293 mutex_lock(&sessions_mutex);
294
295 transport = lttng_transport_find(transport_name);
296 if (!transport) {
297 printk(KERN_WARNING "LTTng: transport %s not found\n",
298 transport_name);
299 goto notransport;
300 }
301 if (!try_module_get(transport->owner)) {
302 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
303 transport_name);
304 goto notransport;
305 }
306
307 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
308 GFP_KERNEL);
309 if (!event_notifier_group)
310 goto nomem;
311
312 /*
313 * Initialize the ring buffer used to store event notifier
314 * notifications.
315 */
316 event_notifier_group->ops = &transport->ops;
317 event_notifier_group->chan = transport->ops.priv->channel_create(
318 transport_name, event_notifier_group, NULL,
319 subbuf_size, num_subbuf, switch_timer_interval,
320 read_timer_interval);
321 if (!event_notifier_group->chan)
322 goto create_error;
323
324 event_notifier_group->transport = transport;
325
326 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
327 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
328 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
329 INIT_HLIST_HEAD(&event_notifier_group->events_ht.table[i]);
330
331 list_add(&event_notifier_group->node, &event_notifier_groups);
332
333 mutex_unlock(&sessions_mutex);
334
335 return event_notifier_group;
336
337 create_error:
338 lttng_kvfree(event_notifier_group);
339 nomem:
340 if (transport)
341 module_put(transport->owner);
342 notransport:
343 mutex_unlock(&sessions_mutex);
344 return NULL;
345 }
346
347 void metadata_cache_destroy(struct kref *kref)
348 {
349 struct lttng_metadata_cache *cache =
350 container_of(kref, struct lttng_metadata_cache, refcount);
351 vfree(cache->data);
352 kfree(cache);
353 }
354
355 void lttng_session_destroy(struct lttng_kernel_session *session)
356 {
357 struct lttng_kernel_channel_buffer_private *chan_priv, *tmpchan_priv;
358 struct lttng_kernel_event_recorder_private *event_recorder_priv, *tmpevent_recorder_priv;
359 struct lttng_metadata_stream *metadata_stream;
360 struct lttng_event_enabler_common *event_enabler, *tmp_event_enabler;
361 int ret;
362
363 mutex_lock(&sessions_mutex);
364 WRITE_ONCE(session->active, 0);
365 list_for_each_entry(chan_priv, &session->priv->chan, node) {
366 ret = lttng_syscalls_unregister_syscall_table(&chan_priv->parent.syscall_table);
367 WARN_ON(ret);
368 }
369 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node)
370 _lttng_event_unregister(&event_recorder_priv->pub->parent);
371 synchronize_trace(); /* Wait for in-flight events to complete */
372 list_for_each_entry(chan_priv, &session->priv->chan, node) {
373 ret = lttng_syscalls_destroy_syscall_table(&chan_priv->parent.syscall_table);
374 WARN_ON(ret);
375 }
376 list_for_each_entry_safe(event_enabler, tmp_event_enabler, &session->priv->enablers_head, node)
377 lttng_event_enabler_destroy(event_enabler);
378 list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv, &session->priv->events, parent.node)
379 _lttng_event_destroy(&event_recorder_priv->pub->parent);
380 list_for_each_entry_safe(chan_priv, tmpchan_priv, &session->priv->chan, node) {
381 BUG_ON(chan_priv->channel_type == METADATA_CHANNEL);
382 _lttng_channel_destroy(chan_priv->pub);
383 }
384 mutex_lock(&session->priv->metadata_cache->lock);
385 list_for_each_entry(metadata_stream, &session->priv->metadata_cache->metadata_stream, list)
386 _lttng_metadata_channel_hangup(metadata_stream);
387 mutex_unlock(&session->priv->metadata_cache->lock);
388 lttng_id_tracker_fini(&session->pid_tracker);
389 lttng_id_tracker_fini(&session->vpid_tracker);
390 lttng_id_tracker_fini(&session->uid_tracker);
391 lttng_id_tracker_fini(&session->vuid_tracker);
392 lttng_id_tracker_fini(&session->gid_tracker);
393 lttng_id_tracker_fini(&session->vgid_tracker);
394 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
395 list_del(&session->priv->list);
396 mutex_unlock(&sessions_mutex);
397 lttng_kvfree(session->priv);
398 lttng_kvfree(session);
399 }
400
401 void lttng_event_notifier_group_destroy(
402 struct lttng_event_notifier_group *event_notifier_group)
403 {
404 struct lttng_event_enabler_common *event_enabler, *tmp_event_enabler;
405 struct lttng_kernel_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
406 int ret;
407
408 if (!event_notifier_group)
409 return;
410
411 mutex_lock(&sessions_mutex);
412
413 ret = lttng_syscalls_unregister_syscall_table(&event_notifier_group->syscall_table);
414 WARN_ON(ret);
415
416 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
417 &event_notifier_group->event_notifiers_head, parent.node)
418 _lttng_event_unregister(&event_notifier_priv->pub->parent);
419
420 /* Wait for in-flight event notifier to complete */
421 synchronize_trace();
422
423 irq_work_sync(&event_notifier_group->wakeup_pending);
424
425 ret = lttng_syscalls_destroy_syscall_table(&event_notifier_group->syscall_table);
426 WARN_ON(ret);
427
428 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
429 &event_notifier_group->enablers_head, node)
430 lttng_event_enabler_destroy(event_enabler);
431
432 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
433 &event_notifier_group->event_notifiers_head, parent.node)
434 _lttng_event_destroy(&event_notifier_priv->pub->parent);
435
436 if (event_notifier_group->error_counter) {
437 struct lttng_counter *error_counter = event_notifier_group->error_counter;
438
439 error_counter->ops->counter_destroy(error_counter->counter);
440 module_put(error_counter->transport->owner);
441 lttng_kvfree(error_counter);
442 event_notifier_group->error_counter = NULL;
443 }
444
445 event_notifier_group->ops->priv->channel_destroy(event_notifier_group->chan);
446 module_put(event_notifier_group->transport->owner);
447 list_del(&event_notifier_group->node);
448
449 mutex_unlock(&sessions_mutex);
450 lttng_kvfree(event_notifier_group);
451 }
452
453 int lttng_session_statedump(struct lttng_kernel_session *session)
454 {
455 int ret;
456
457 mutex_lock(&sessions_mutex);
458 ret = lttng_statedump_start(session);
459 mutex_unlock(&sessions_mutex);
460 return ret;
461 }
462
463 int lttng_session_enable(struct lttng_kernel_session *session)
464 {
465 int ret = 0;
466 struct lttng_kernel_channel_buffer_private *chan_priv;
467
468 mutex_lock(&sessions_mutex);
469 if (session->active) {
470 ret = -EBUSY;
471 goto end;
472 }
473
474 /* Set transient enabler state to "enabled" */
475 session->priv->tstate = 1;
476
477 /* We need to sync enablers with session before activation. */
478 lttng_session_sync_event_enablers(session);
479
480 /*
481 * Snapshot the number of events per channel to know the type of header
482 * we need to use.
483 */
484 list_for_each_entry(chan_priv, &session->priv->chan, node) {
485 if (chan_priv->header_type)
486 continue; /* don't change it if session stop/restart */
487 if (chan_priv->free_event_id < 31)
488 chan_priv->header_type = 1; /* compact */
489 else
490 chan_priv->header_type = 2; /* large */
491 }
492
493 /* Clear each stream's quiescent state. */
494 list_for_each_entry(chan_priv, &session->priv->chan, node) {
495 if (chan_priv->channel_type != METADATA_CHANNEL)
496 lib_ring_buffer_clear_quiescent_channel(chan_priv->rb_chan);
497 }
498
499 WRITE_ONCE(session->active, 1);
500 WRITE_ONCE(session->priv->been_active, 1);
501 ret = _lttng_session_metadata_statedump(session);
502 if (ret) {
503 WRITE_ONCE(session->active, 0);
504 goto end;
505 }
506 ret = lttng_statedump_start(session);
507 if (ret)
508 WRITE_ONCE(session->active, 0);
509 end:
510 mutex_unlock(&sessions_mutex);
511 return ret;
512 }
513
514 int lttng_session_disable(struct lttng_kernel_session *session)
515 {
516 int ret = 0;
517 struct lttng_kernel_channel_buffer_private *chan_priv;
518
519 mutex_lock(&sessions_mutex);
520 if (!session->active) {
521 ret = -EBUSY;
522 goto end;
523 }
524 WRITE_ONCE(session->active, 0);
525
526 /* Set transient enabler state to "disabled" */
527 session->priv->tstate = 0;
528 lttng_session_sync_event_enablers(session);
529
530 /* Set each stream's quiescent state. */
531 list_for_each_entry(chan_priv, &session->priv->chan, node) {
532 if (chan_priv->channel_type != METADATA_CHANNEL)
533 lib_ring_buffer_set_quiescent_channel(chan_priv->rb_chan);
534 }
535 end:
536 mutex_unlock(&sessions_mutex);
537 return ret;
538 }
539
540 int lttng_session_metadata_regenerate(struct lttng_kernel_session *session)
541 {
542 int ret = 0;
543 struct lttng_kernel_channel_buffer_private *chan_priv;
544 struct lttng_kernel_event_recorder_private *event_recorder_priv;
545 struct lttng_metadata_cache *cache = session->priv->metadata_cache;
546 struct lttng_metadata_stream *stream;
547
548 mutex_lock(&sessions_mutex);
549 if (!session->active) {
550 ret = -EBUSY;
551 goto end;
552 }
553
554 mutex_lock(&cache->lock);
555 memset(cache->data, 0, cache->cache_alloc);
556 cache->metadata_written = 0;
557 cache->version++;
558 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list) {
559 stream->metadata_out = 0;
560 stream->metadata_in = 0;
561 }
562 mutex_unlock(&cache->lock);
563
564 session->priv->metadata_dumped = 0;
565 list_for_each_entry(chan_priv, &session->priv->chan, node) {
566 chan_priv->metadata_dumped = 0;
567 }
568
569 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
570 event_recorder_priv->metadata_dumped = 0;
571 }
572
573 ret = _lttng_session_metadata_statedump(session);
574
575 end:
576 mutex_unlock(&sessions_mutex);
577 return ret;
578 }
579
580 static
581 bool is_channel_buffer_metadata(struct lttng_kernel_channel_common *channel)
582 {
583 struct lttng_kernel_channel_buffer *chan_buf;
584
585 if (channel->type != LTTNG_KERNEL_CHANNEL_TYPE_BUFFER)
586 return false;
587 chan_buf = container_of(channel, struct lttng_kernel_channel_buffer, parent);
588 if (chan_buf->priv->channel_type == METADATA_CHANNEL)
589 return true;
590 return false;
591 }
592
593 int lttng_channel_enable(struct lttng_kernel_channel_common *channel)
594 {
595 int ret = 0;
596
597 mutex_lock(&sessions_mutex);
598 if (is_channel_buffer_metadata(channel)) {
599 ret = -EPERM;
600 goto end;
601 }
602 if (channel->enabled) {
603 ret = -EEXIST;
604 goto end;
605 }
606 /* Set transient enabler state to "enabled" */
607 channel->priv->tstate = 1;
608 lttng_session_sync_event_enablers(channel->session);
609 /* Set atomically the state to "enabled" */
610 WRITE_ONCE(channel->enabled, 1);
611 end:
612 mutex_unlock(&sessions_mutex);
613 return ret;
614 }
615
616 int lttng_channel_disable(struct lttng_kernel_channel_common *channel)
617 {
618 int ret = 0;
619
620 mutex_lock(&sessions_mutex);
621 if (is_channel_buffer_metadata(channel)) {
622 ret = -EPERM;
623 goto end;
624 }
625 if (!channel->enabled) {
626 ret = -EEXIST;
627 goto end;
628 }
629 /* Set atomically the state to "disabled" */
630 WRITE_ONCE(channel->enabled, 0);
631 /* Set transient enabler state to "enabled" */
632 channel->priv->tstate = 0;
633 lttng_session_sync_event_enablers(channel->session);
634 end:
635 mutex_unlock(&sessions_mutex);
636 return ret;
637 }
638
639 int lttng_event_enable(struct lttng_kernel_event_common *event)
640 {
641 int ret = 0;
642
643 mutex_lock(&sessions_mutex);
644 switch (event->type) {
645 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
646 {
647 struct lttng_kernel_event_recorder *event_recorder =
648 container_of(event, struct lttng_kernel_event_recorder, parent);
649
650 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
651 ret = -EPERM;
652 goto end;
653 }
654 break;
655 }
656 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
657 switch (event->priv->instrumentation) {
658 case LTTNG_KERNEL_ABI_KRETPROBE:
659 ret = -EINVAL;
660 goto end;
661 default:
662 break;
663 }
664 break;
665 default:
666 break;
667 }
668
669 if (event->enabled) {
670 ret = -EEXIST;
671 goto end;
672 }
673 switch (event->priv->instrumentation) {
674 case LTTNG_KERNEL_ABI_TRACEPOINT:
675 lttng_fallthrough;
676 case LTTNG_KERNEL_ABI_SYSCALL:
677 ret = -EINVAL;
678 break;
679
680 case LTTNG_KERNEL_ABI_KPROBE:
681 lttng_fallthrough;
682 case LTTNG_KERNEL_ABI_UPROBE:
683 WRITE_ONCE(event->enabled, 1);
684 break;
685
686 case LTTNG_KERNEL_ABI_KRETPROBE:
687 ret = lttng_kretprobes_event_enable_state(event, 1);
688 break;
689
690 case LTTNG_KERNEL_ABI_FUNCTION:
691 lttng_fallthrough;
692 case LTTNG_KERNEL_ABI_NOOP:
693 lttng_fallthrough;
694 default:
695 WARN_ON_ONCE(1);
696 ret = -EINVAL;
697 }
698 end:
699 mutex_unlock(&sessions_mutex);
700 return ret;
701 }
702
703 int lttng_event_disable(struct lttng_kernel_event_common *event)
704 {
705 int ret = 0;
706
707 mutex_lock(&sessions_mutex);
708 switch (event->type) {
709 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
710 {
711 struct lttng_kernel_event_recorder *event_recorder =
712 container_of(event, struct lttng_kernel_event_recorder, parent);
713
714 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
715 ret = -EPERM;
716 goto end;
717 }
718 break;
719 }
720 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
721 switch (event->priv->instrumentation) {
722 case LTTNG_KERNEL_ABI_KRETPROBE:
723 ret = -EINVAL;
724 goto end;
725 default:
726 break;
727 }
728 break;
729 default:
730 break;
731 }
732
733 if (!event->enabled) {
734 ret = -EEXIST;
735 goto end;
736 }
737 switch (event->priv->instrumentation) {
738 case LTTNG_KERNEL_ABI_TRACEPOINT:
739 lttng_fallthrough;
740 case LTTNG_KERNEL_ABI_SYSCALL:
741 ret = -EINVAL;
742 break;
743
744 case LTTNG_KERNEL_ABI_KPROBE:
745 lttng_fallthrough;
746 case LTTNG_KERNEL_ABI_UPROBE:
747 WRITE_ONCE(event->enabled, 0);
748 break;
749
750 case LTTNG_KERNEL_ABI_KRETPROBE:
751 ret = lttng_kretprobes_event_enable_state(event, 0);
752 break;
753
754 case LTTNG_KERNEL_ABI_FUNCTION:
755 lttng_fallthrough;
756 case LTTNG_KERNEL_ABI_NOOP:
757 lttng_fallthrough;
758 default:
759 WARN_ON_ONCE(1);
760 ret = -EINVAL;
761 }
762 end:
763 mutex_unlock(&sessions_mutex);
764 return ret;
765 }
766
767 struct lttng_kernel_channel_buffer *lttng_channel_buffer_create(struct lttng_kernel_session *session,
768 const char *transport_name,
769 void *buf_addr,
770 size_t subbuf_size, size_t num_subbuf,
771 unsigned int switch_timer_interval,
772 unsigned int read_timer_interval,
773 enum channel_type channel_type)
774 {
775 struct lttng_kernel_channel_buffer *chan;
776 struct lttng_kernel_channel_buffer_private *chan_priv;
777 struct lttng_transport *transport = NULL;
778
779 mutex_lock(&sessions_mutex);
780 if (session->priv->been_active && channel_type != METADATA_CHANNEL)
781 goto active; /* Refuse to add channel to active session */
782 transport = lttng_transport_find(transport_name);
783 if (!transport) {
784 printk(KERN_WARNING "LTTng: transport %s not found\n",
785 transport_name);
786 goto notransport;
787 }
788 if (!try_module_get(transport->owner)) {
789 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
790 goto notransport;
791 }
792 chan = kzalloc(sizeof(struct lttng_kernel_channel_buffer), GFP_KERNEL);
793 if (!chan)
794 goto nomem;
795 chan_priv = kzalloc(sizeof(struct lttng_kernel_channel_buffer_private), GFP_KERNEL);
796 if (!chan_priv)
797 goto nomem_priv;
798 chan->priv = chan_priv;
799 chan_priv->pub = chan;
800 chan->parent.type = LTTNG_KERNEL_CHANNEL_TYPE_BUFFER;
801 chan->parent.session = session;
802 chan->priv->id = session->priv->free_chan_id++;
803 chan->ops = &transport->ops;
804 /*
805 * Note: the channel creation op already writes into the packet
806 * headers. Therefore the "chan" information used as input
807 * should be already accessible.
808 */
809 chan->priv->rb_chan = transport->ops.priv->channel_create(transport_name,
810 chan, buf_addr, subbuf_size, num_subbuf,
811 switch_timer_interval, read_timer_interval);
812 if (!chan->priv->rb_chan)
813 goto create_error;
814 chan->priv->parent.tstate = 1;
815 chan->parent.enabled = 1;
816 chan->priv->transport = transport;
817 chan->priv->channel_type = channel_type;
818 list_add(&chan->priv->node, &session->priv->chan);
819 mutex_unlock(&sessions_mutex);
820 return chan;
821
822 create_error:
823 kfree(chan_priv);
824 nomem_priv:
825 kfree(chan);
826 nomem:
827 if (transport)
828 module_put(transport->owner);
829 notransport:
830 active:
831 mutex_unlock(&sessions_mutex);
832 return NULL;
833 }
834
835 /*
836 * Only used internally at session destruction for per-cpu channels, and
837 * when metadata channel is released.
838 * Needs to be called with sessions mutex held.
839 */
840 static
841 void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan)
842 {
843 chan->ops->priv->channel_destroy(chan->priv->rb_chan);
844 module_put(chan->priv->transport->owner);
845 list_del(&chan->priv->node);
846 lttng_kernel_destroy_context(chan->priv->ctx);
847 kfree(chan->priv);
848 kfree(chan);
849 }
850
851 void lttng_metadata_channel_destroy(struct lttng_kernel_channel_buffer *chan)
852 {
853 BUG_ON(chan->priv->channel_type != METADATA_CHANNEL);
854
855 /* Protect the metadata cache with the sessions_mutex. */
856 mutex_lock(&sessions_mutex);
857 _lttng_channel_destroy(chan);
858 mutex_unlock(&sessions_mutex);
859 }
860 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
861
862 static
863 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
864 {
865 stream->finalized = 1;
866 wake_up_interruptible(&stream->read_wait);
867 }
868
869 static
870 bool lttng_kernel_event_id_available(struct lttng_event_enabler_common *event_enabler)
871 {
872 struct lttng_kernel_abi_event *event_param = &event_enabler->event_param;
873 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
874
875 switch (event_enabler->enabler_type) {
876 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
877 {
878 struct lttng_event_recorder_enabler *event_recorder_enabler =
879 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
880 struct lttng_kernel_channel_buffer *chan = event_recorder_enabler->chan;
881
882 switch (itype) {
883 case LTTNG_KERNEL_ABI_TRACEPOINT:
884 lttng_fallthrough;
885 case LTTNG_KERNEL_ABI_KPROBE:
886 lttng_fallthrough;
887 case LTTNG_KERNEL_ABI_SYSCALL:
888 lttng_fallthrough;
889 case LTTNG_KERNEL_ABI_UPROBE:
890 if (chan->priv->free_event_id == -1U)
891 return false;
892 return true;
893 case LTTNG_KERNEL_ABI_KRETPROBE:
894 /* kretprobes require 2 event IDs. */
895 if (chan->priv->free_event_id >= -2U)
896 return false;
897 return true;
898 default:
899 WARN_ON_ONCE(1);
900 return false;
901 }
902 }
903 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
904 return true;
905 default:
906 WARN_ON_ONCE(1);
907 return false;
908 }
909 }
910
911 static
912 struct lttng_kernel_event_common *lttng_kernel_event_alloc(struct lttng_event_enabler_common *event_enabler)
913 {
914 struct lttng_kernel_abi_event *event_param = &event_enabler->event_param;
915 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
916
917 switch (event_enabler->enabler_type) {
918 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
919 {
920 struct lttng_event_recorder_enabler *event_recorder_enabler =
921 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
922 struct lttng_kernel_event_recorder *event_recorder;
923 struct lttng_kernel_event_recorder_private *event_recorder_priv;
924 struct lttng_kernel_channel_buffer *chan = event_recorder_enabler->chan;
925
926 event_recorder = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
927 if (!event_recorder)
928 return NULL;
929 event_recorder_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
930 if (!event_recorder_priv) {
931 kmem_cache_free(event_recorder_private_cache, event_recorder);
932 return NULL;
933 }
934 event_recorder_priv->pub = event_recorder;
935 event_recorder_priv->parent.pub = &event_recorder->parent;
936 event_recorder->priv = event_recorder_priv;
937 event_recorder->parent.priv = &event_recorder_priv->parent;
938
939 event_recorder->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
940 event_recorder->parent.run_filter = lttng_kernel_interpret_event_filter;
941 event_recorder->priv->parent.instrumentation = itype;
942 INIT_LIST_HEAD(&event_recorder->priv->parent.filter_bytecode_runtime_head);
943 INIT_LIST_HEAD(&event_recorder->priv->parent.enablers_ref_head);
944
945 event_recorder->chan = chan;
946 event_recorder->priv->id = chan->priv->free_event_id++;
947 return &event_recorder->parent;
948 }
949 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
950 {
951 struct lttng_event_notifier_enabler *event_notifier_enabler =
952 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
953 struct lttng_kernel_event_notifier *event_notifier;
954 struct lttng_kernel_event_notifier_private *event_notifier_priv;
955
956 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
957 if (!event_notifier)
958 return NULL;
959 event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
960 if (!event_notifier_priv) {
961 kmem_cache_free(event_notifier_private_cache, event_notifier);
962 return NULL;
963 }
964 event_notifier_priv->pub = event_notifier;
965 event_notifier_priv->parent.pub = &event_notifier->parent;
966 event_notifier->priv = event_notifier_priv;
967 event_notifier->parent.priv = &event_notifier_priv->parent;
968
969 event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
970 event_notifier->parent.run_filter = lttng_kernel_interpret_event_filter;
971 event_notifier->priv->parent.instrumentation = itype;
972 event_notifier->priv->parent.user_token = event_enabler->user_token;
973 INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
974 INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
975
976 event_notifier->priv->group = event_notifier_enabler->group;
977 event_notifier->priv->error_counter_index = event_notifier_enabler->error_counter_index;
978 event_notifier->priv->num_captures = 0;
979 event_notifier->notification_send = lttng_event_notifier_notification_send;
980 INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
981 return &event_notifier->parent;
982 }
983 default:
984 return NULL;
985 }
986 }
987
988 static
989 void lttng_kernel_event_free(struct lttng_kernel_event_common *event)
990 {
991 switch (event->type) {
992 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
993 {
994 struct lttng_kernel_event_recorder *event_recorder =
995 container_of(event, struct lttng_kernel_event_recorder, parent);
996
997 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
998 kmem_cache_free(event_recorder_cache, event_recorder);
999 break;
1000 }
1001 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1002 {
1003 struct lttng_kernel_event_notifier *event_notifier =
1004 container_of(event, struct lttng_kernel_event_notifier, parent);
1005
1006 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1007 kmem_cache_free(event_notifier_cache, event_notifier);
1008 break;
1009 }
1010 default:
1011 WARN_ON_ONCE(1);
1012 }
1013 }
1014
1015 static
1016 int lttng_kernel_event_notifier_clear_error_counter(struct lttng_kernel_event_common *event)
1017 {
1018 switch (event->type) {
1019 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1020 return 0;
1021 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1022 {
1023 struct lttng_kernel_event_notifier *event_notifier =
1024 container_of(event, struct lttng_kernel_event_notifier, parent);
1025 struct lttng_counter *error_counter;
1026 struct lttng_event_notifier_group *event_notifier_group = event_notifier->priv->group;
1027 size_t dimension_index[1];
1028 int ret;
1029
1030 /*
1031 * Clear the error counter bucket. The sessiond keeps track of which
1032 * bucket is currently in use. We trust it. The session lock
1033 * synchronizes against concurrent creation of the error
1034 * counter.
1035 */
1036 error_counter = event_notifier_group->error_counter;
1037 if (!error_counter)
1038 return 0;
1039 /*
1040 * Check that the index is within the boundary of the counter.
1041 */
1042 if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
1043 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1044 event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
1045 return -EINVAL;
1046 }
1047
1048 dimension_index[0] = event_notifier->priv->error_counter_index;
1049 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1050 if (ret) {
1051 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1052 event_notifier->priv->error_counter_index);
1053 return -EINVAL;
1054 }
1055 return 0;
1056 }
1057 default:
1058 return -EINVAL;
1059 }
1060 }
1061
1062 /*
1063 * Supports event creation while tracing session is active.
1064 * Needs to be called with sessions mutex held.
1065 */
1066 struct lttng_kernel_event_common *_lttng_kernel_event_create(struct lttng_event_enabler_common *event_enabler,
1067 const struct lttng_kernel_event_desc *event_desc)
1068 {
1069 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(event_enabler);
1070 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(event_enabler);
1071 struct lttng_kernel_abi_event *event_param = &event_enabler->event_param;
1072 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
1073 struct lttng_kernel_event_common_private *event_priv;
1074 struct lttng_kernel_event_common *event;
1075 const char *event_name;
1076 struct hlist_head *head;
1077 int ret;
1078
1079 if (!lttng_kernel_event_id_available(event_enabler)) {
1080 ret = -EMFILE;
1081 goto full;
1082 }
1083
1084 switch (itype) {
1085 case LTTNG_KERNEL_ABI_TRACEPOINT:
1086 event_name = event_desc->event_name;
1087 break;
1088
1089 case LTTNG_KERNEL_ABI_KPROBE:
1090 lttng_fallthrough;
1091 case LTTNG_KERNEL_ABI_UPROBE:
1092 lttng_fallthrough;
1093 case LTTNG_KERNEL_ABI_KRETPROBE:
1094 lttng_fallthrough;
1095 case LTTNG_KERNEL_ABI_SYSCALL:
1096 event_name = event_param->name;
1097 break;
1098
1099 case LTTNG_KERNEL_ABI_FUNCTION:
1100 lttng_fallthrough;
1101 case LTTNG_KERNEL_ABI_NOOP:
1102 lttng_fallthrough;
1103 default:
1104 WARN_ON_ONCE(1);
1105 ret = -EINVAL;
1106 goto type_error;
1107 }
1108
1109 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, event_name);
1110 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
1111 if (lttng_event_enabler_event_name_match_event(event_enabler, event_name, event_priv->pub)) {
1112 ret = -EEXIST;
1113 goto exist;
1114 }
1115 }
1116
1117 event = lttng_kernel_event_alloc(event_enabler);
1118 if (!event) {
1119 ret = -ENOMEM;
1120 goto alloc_error;
1121 }
1122
1123 switch (itype) {
1124 case LTTNG_KERNEL_ABI_TRACEPOINT:
1125 /* Event will be enabled by enabler sync. */
1126 event->enabled = 0;
1127 event->priv->registered = 0;
1128 event->priv->desc = lttng_event_desc_get(event_name);
1129 if (!event->priv->desc) {
1130 ret = -ENOENT;
1131 goto register_error;
1132 }
1133 /* Populate lttng_event structure before event registration. */
1134 smp_wmb();
1135 break;
1136
1137 case LTTNG_KERNEL_ABI_KPROBE:
1138 /*
1139 * Needs to be explicitly enabled after creation, since
1140 * we may want to apply filters.
1141 */
1142 event->enabled = 0;
1143 event->priv->registered = 1;
1144 /*
1145 * Populate lttng_event structure before event
1146 * registration.
1147 */
1148 smp_wmb();
1149 ret = lttng_kprobes_register_event(event_name,
1150 event_param->u.kprobe.symbol_name,
1151 event_param->u.kprobe.offset,
1152 event_param->u.kprobe.addr,
1153 event);
1154 if (ret) {
1155 ret = -EINVAL;
1156 goto register_error;
1157 }
1158 ret = try_module_get(event->priv->desc->owner);
1159 WARN_ON_ONCE(!ret);
1160 break;
1161
1162 case LTTNG_KERNEL_ABI_KRETPROBE:
1163 {
1164 struct lttng_kernel_event_common *event_return;
1165
1166 /* kretprobe defines 2 events */
1167 /*
1168 * Needs to be explicitly enabled after creation, since
1169 * we may want to apply filters.
1170 */
1171 event->enabled = 0;
1172 event->priv->registered = 1;
1173
1174 event_return = lttng_kernel_event_alloc(event_enabler);
1175 if (!event) {
1176 ret = -ENOMEM;
1177 goto alloc_error;
1178 }
1179
1180 event_return->enabled = 0;
1181 event_return->priv->registered = 1;
1182
1183 /*
1184 * Populate lttng_event structure before kretprobe registration.
1185 */
1186 smp_wmb();
1187 ret = lttng_kretprobes_register(event_name,
1188 event_param->u.kretprobe.symbol_name,
1189 event_param->u.kretprobe.offset,
1190 event_param->u.kretprobe.addr,
1191 event, event_return);
1192 if (ret) {
1193 lttng_kernel_event_free(event_return);
1194 ret = -EINVAL;
1195 goto register_error;
1196 }
1197 /* Take 2 refs on the module: one per event. */
1198 ret = try_module_get(event->priv->desc->owner);
1199 WARN_ON_ONCE(!ret);
1200 ret = try_module_get(event_return->priv->desc->owner);
1201 WARN_ON_ONCE(!ret);
1202 ret = _lttng_event_recorder_metadata_statedump(event_return);
1203 WARN_ON_ONCE(ret > 0);
1204 if (ret) {
1205 lttng_kernel_event_free(event_return);
1206 module_put(event_return->priv->desc->owner);
1207 module_put(event->priv->desc->owner);
1208 goto statedump_error;
1209 }
1210 list_add(&event_return->priv->node, event_list_head);
1211 break;
1212 }
1213
1214 case LTTNG_KERNEL_ABI_SYSCALL:
1215 /*
1216 * Needs to be explicitly enabled after creation, since
1217 * we may want to apply filters.
1218 */
1219 event->enabled = 0;
1220 event->priv->registered = 0;
1221 event->priv->desc = event_desc;
1222 switch (event_param->u.syscall.entryexit) {
1223 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1224 ret = -EINVAL;
1225 goto register_error;
1226 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1227 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1228 break;
1229 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1230 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1231 break;
1232 }
1233 switch (event_param->u.syscall.abi) {
1234 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1235 ret = -EINVAL;
1236 goto register_error;
1237 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1238 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1239 break;
1240 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1241 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1242 break;
1243 }
1244 if (!event->priv->desc) {
1245 ret = -EINVAL;
1246 goto register_error;
1247 }
1248 break;
1249
1250 case LTTNG_KERNEL_ABI_UPROBE:
1251 /*
1252 * Needs to be explicitly enabled after creation, since
1253 * we may want to apply filters.
1254 */
1255 event->enabled = 0;
1256 event->priv->registered = 1;
1257
1258 /*
1259 * Populate lttng_event structure before event
1260 * registration.
1261 */
1262 smp_wmb();
1263
1264 ret = lttng_uprobes_register_event(event_param->name,
1265 event_param->u.uprobe.fd,
1266 event);
1267 if (ret)
1268 goto register_error;
1269 ret = try_module_get(event->priv->desc->owner);
1270 WARN_ON_ONCE(!ret);
1271 break;
1272
1273 case LTTNG_KERNEL_ABI_FUNCTION:
1274 lttng_fallthrough;
1275 case LTTNG_KERNEL_ABI_NOOP:
1276 lttng_fallthrough;
1277 default:
1278 WARN_ON_ONCE(1);
1279 ret = -EINVAL;
1280 goto register_error;
1281 }
1282
1283 ret = _lttng_event_recorder_metadata_statedump(event);
1284 WARN_ON_ONCE(ret > 0);
1285 if (ret) {
1286 goto statedump_error;
1287 }
1288
1289 ret = lttng_kernel_event_notifier_clear_error_counter(event);
1290 if (ret)
1291 goto register_error;
1292
1293 hlist_add_head(&event->priv->hlist_node, head);
1294 list_add(&event->priv->node, event_list_head);
1295
1296 return event;
1297
1298 statedump_error:
1299 /* If a statedump error occurs, events will not be readable. */
1300 register_error:
1301 lttng_kernel_event_free(event);
1302 alloc_error:
1303 exist:
1304 type_error:
1305 full:
1306 return ERR_PTR(ret);
1307 }
1308
1309 struct lttng_kernel_event_common *lttng_kernel_event_create(struct lttng_event_enabler_common *event_enabler,
1310 const struct lttng_kernel_event_desc *event_desc)
1311 {
1312 struct lttng_kernel_event_common *event;
1313
1314 mutex_lock(&sessions_mutex);
1315 event = _lttng_kernel_event_create(event_enabler, event_desc);
1316 mutex_unlock(&sessions_mutex);
1317 return event;
1318 }
1319
1320 int lttng_kernel_counter_read(struct lttng_counter *counter,
1321 const size_t *dim_indexes, int32_t cpu,
1322 int64_t *val, bool *overflow, bool *underflow)
1323 {
1324 return counter->ops->counter_read(counter->counter, dim_indexes,
1325 cpu, val, overflow, underflow);
1326 }
1327
1328 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1329 const size_t *dim_indexes, int64_t *val,
1330 bool *overflow, bool *underflow)
1331 {
1332 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1333 val, overflow, underflow);
1334 }
1335
1336 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1337 const size_t *dim_indexes)
1338 {
1339 return counter->ops->counter_clear(counter->counter, dim_indexes);
1340 }
1341
1342 /* Only used for tracepoints and system calls for now. */
1343 static
1344 void register_event(struct lttng_kernel_event_common *event)
1345 {
1346 const struct lttng_kernel_event_desc *desc;
1347 int ret = -EINVAL;
1348
1349 WARN_ON_ONCE(event->priv->registered);
1350
1351 desc = event->priv->desc;
1352 switch (event->priv->instrumentation) {
1353 case LTTNG_KERNEL_ABI_TRACEPOINT:
1354 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1355 desc->tp_class->probe_callback,
1356 event);
1357 break;
1358
1359 case LTTNG_KERNEL_ABI_SYSCALL:
1360 ret = lttng_syscall_filter_enable_event(event);
1361 break;
1362
1363 case LTTNG_KERNEL_ABI_KPROBE:
1364 lttng_fallthrough;
1365 case LTTNG_KERNEL_ABI_UPROBE:
1366 ret = 0;
1367 break;
1368
1369 case LTTNG_KERNEL_ABI_KRETPROBE:
1370 switch (event->type) {
1371 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1372 ret = 0;
1373 break;
1374 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1375 WARN_ON_ONCE(1);
1376 break;
1377 }
1378 break;
1379
1380 case LTTNG_KERNEL_ABI_FUNCTION:
1381 lttng_fallthrough;
1382 case LTTNG_KERNEL_ABI_NOOP:
1383 lttng_fallthrough;
1384 default:
1385 WARN_ON_ONCE(1);
1386 }
1387 WARN_ON_ONCE(ret);
1388 if (!ret)
1389 event->priv->registered = 1;
1390 }
1391
1392 static
1393 void unregister_event(struct lttng_kernel_event_common *event)
1394 {
1395 struct lttng_kernel_event_common_private *event_priv = event->priv;
1396 const struct lttng_kernel_event_desc *desc;
1397 int ret = -EINVAL;
1398
1399 WARN_ON_ONCE(!event->priv->registered);
1400
1401 desc = event_priv->desc;
1402 switch (event_priv->instrumentation) {
1403 case LTTNG_KERNEL_ABI_TRACEPOINT:
1404 ret = lttng_wrapper_tracepoint_probe_unregister(event_priv->desc->event_kname,
1405 event_priv->desc->tp_class->probe_callback,
1406 event);
1407 break;
1408
1409 case LTTNG_KERNEL_ABI_KPROBE:
1410 lttng_kprobes_unregister_event(event);
1411 ret = 0;
1412 break;
1413
1414 case LTTNG_KERNEL_ABI_KRETPROBE:
1415 switch (event->type) {
1416 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1417 lttng_kretprobes_unregister(event);
1418 ret = 0;
1419 break;
1420 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1421 WARN_ON_ONCE(1);
1422 break;
1423 }
1424 break;
1425
1426 case LTTNG_KERNEL_ABI_SYSCALL:
1427 ret = lttng_syscall_filter_disable_event(event);
1428 break;
1429
1430 case LTTNG_KERNEL_ABI_NOOP:
1431 switch (event->type) {
1432 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1433 ret = 0;
1434 break;
1435 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1436 WARN_ON_ONCE(1);
1437 break;
1438 }
1439 break;
1440
1441 case LTTNG_KERNEL_ABI_UPROBE:
1442 lttng_uprobes_unregister_event(event);
1443 ret = 0;
1444 break;
1445
1446 case LTTNG_KERNEL_ABI_FUNCTION:
1447 lttng_fallthrough;
1448 default:
1449 WARN_ON_ONCE(1);
1450 }
1451 WARN_ON_ONCE(ret);
1452 if (!ret)
1453 event_priv->registered = 0;
1454 }
1455
1456 static
1457 void _lttng_event_unregister(struct lttng_kernel_event_common *event)
1458 {
1459 if (event->priv->registered)
1460 unregister_event(event);
1461 }
1462
1463 /*
1464 * Only used internally at session destruction.
1465 */
1466 static
1467 void _lttng_event_destroy(struct lttng_kernel_event_common *event)
1468 {
1469 struct lttng_kernel_event_common_private *event_priv = event->priv;
1470 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1471
1472 lttng_free_event_filter_runtime(event);
1473 /* Free event enabler refs */
1474 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1475 &event_priv->enablers_ref_head, node)
1476 kfree(enabler_ref);
1477
1478 switch (event->type) {
1479 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1480 {
1481 struct lttng_kernel_event_recorder *event_recorder =
1482 container_of(event, struct lttng_kernel_event_recorder, parent);
1483
1484 switch (event_priv->instrumentation) {
1485 case LTTNG_KERNEL_ABI_TRACEPOINT:
1486 lttng_event_desc_put(event_priv->desc);
1487 break;
1488
1489 case LTTNG_KERNEL_ABI_KPROBE:
1490 module_put(event_priv->desc->owner);
1491 lttng_kprobes_destroy_event_private(&event_recorder->parent);
1492 break;
1493
1494 case LTTNG_KERNEL_ABI_KRETPROBE:
1495 module_put(event_priv->desc->owner);
1496 lttng_kretprobes_destroy_private(&event_recorder->parent);
1497 break;
1498
1499 case LTTNG_KERNEL_ABI_SYSCALL:
1500 break;
1501
1502 case LTTNG_KERNEL_ABI_UPROBE:
1503 module_put(event_priv->desc->owner);
1504 lttng_uprobes_destroy_event_private(&event_recorder->parent);
1505 break;
1506
1507 case LTTNG_KERNEL_ABI_FUNCTION:
1508 lttng_fallthrough;
1509 case LTTNG_KERNEL_ABI_NOOP:
1510 lttng_fallthrough;
1511 default:
1512 WARN_ON_ONCE(1);
1513 }
1514 list_del(&event_recorder->priv->parent.node);
1515 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
1516 kmem_cache_free(event_recorder_cache, event_recorder);
1517 break;
1518 }
1519 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1520 {
1521 struct lttng_kernel_event_notifier *event_notifier =
1522 container_of(event, struct lttng_kernel_event_notifier, parent);
1523
1524 switch (event_notifier->priv->parent.instrumentation) {
1525 case LTTNG_KERNEL_ABI_TRACEPOINT:
1526 lttng_event_desc_put(event_notifier->priv->parent.desc);
1527 break;
1528
1529 case LTTNG_KERNEL_ABI_KPROBE:
1530 module_put(event_notifier->priv->parent.desc->owner);
1531 lttng_kprobes_destroy_event_private(&event_notifier->parent);
1532 break;
1533
1534 case LTTNG_KERNEL_ABI_SYSCALL:
1535 break;
1536
1537 case LTTNG_KERNEL_ABI_UPROBE:
1538 module_put(event_notifier->priv->parent.desc->owner);
1539 lttng_uprobes_destroy_event_private(&event_notifier->parent);
1540 break;
1541
1542 case LTTNG_KERNEL_ABI_KRETPROBE:
1543 lttng_fallthrough;
1544 case LTTNG_KERNEL_ABI_FUNCTION:
1545 lttng_fallthrough;
1546 case LTTNG_KERNEL_ABI_NOOP:
1547 lttng_fallthrough;
1548 default:
1549 WARN_ON_ONCE(1);
1550 }
1551 list_del(&event_notifier->priv->parent.node);
1552 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1553 kmem_cache_free(event_notifier_cache, event_notifier);
1554 break;
1555 }
1556 default:
1557 WARN_ON_ONCE(1);
1558 }
1559 }
1560
1561 struct lttng_kernel_id_tracker *get_tracker(struct lttng_kernel_session *session,
1562 enum tracker_type tracker_type)
1563 {
1564 switch (tracker_type) {
1565 case TRACKER_PID:
1566 return &session->pid_tracker;
1567 case TRACKER_VPID:
1568 return &session->vpid_tracker;
1569 case TRACKER_UID:
1570 return &session->uid_tracker;
1571 case TRACKER_VUID:
1572 return &session->vuid_tracker;
1573 case TRACKER_GID:
1574 return &session->gid_tracker;
1575 case TRACKER_VGID:
1576 return &session->vgid_tracker;
1577 default:
1578 WARN_ON_ONCE(1);
1579 return NULL;
1580 }
1581 }
1582
1583 int lttng_session_track_id(struct lttng_kernel_session *session,
1584 enum tracker_type tracker_type, int id)
1585 {
1586 struct lttng_kernel_id_tracker *tracker;
1587 int ret;
1588
1589 tracker = get_tracker(session, tracker_type);
1590 if (!tracker)
1591 return -EINVAL;
1592 if (id < -1)
1593 return -EINVAL;
1594 mutex_lock(&sessions_mutex);
1595 if (id == -1) {
1596 /* track all ids: destroy tracker. */
1597 lttng_id_tracker_destroy(tracker, true);
1598 ret = 0;
1599 } else {
1600 ret = lttng_id_tracker_add(tracker, id);
1601 }
1602 mutex_unlock(&sessions_mutex);
1603 return ret;
1604 }
1605
1606 int lttng_session_untrack_id(struct lttng_kernel_session *session,
1607 enum tracker_type tracker_type, int id)
1608 {
1609 struct lttng_kernel_id_tracker *tracker;
1610 int ret;
1611
1612 tracker = get_tracker(session, tracker_type);
1613 if (!tracker)
1614 return -EINVAL;
1615 if (id < -1)
1616 return -EINVAL;
1617 mutex_lock(&sessions_mutex);
1618 if (id == -1) {
1619 /* untrack all ids: replace by empty tracker. */
1620 ret = lttng_id_tracker_empty_set(tracker);
1621 } else {
1622 ret = lttng_id_tracker_del(tracker, id);
1623 }
1624 mutex_unlock(&sessions_mutex);
1625 return ret;
1626 }
1627
1628 static
1629 void *id_list_start(struct seq_file *m, loff_t *pos)
1630 {
1631 struct lttng_kernel_id_tracker *id_tracker = m->private;
1632 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1633 struct lttng_id_hash_node *e;
1634 int iter = 0, i;
1635
1636 mutex_lock(&sessions_mutex);
1637 if (id_tracker_p) {
1638 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1639 struct hlist_head *head = &id_tracker_p->id_hash[i];
1640
1641 lttng_hlist_for_each_entry(e, head, hlist) {
1642 if (iter++ >= *pos)
1643 return e;
1644 }
1645 }
1646 } else {
1647 /* ID tracker disabled. */
1648 if (iter >= *pos && iter == 0) {
1649 return id_tracker_p; /* empty tracker */
1650 }
1651 iter++;
1652 }
1653 /* End of list */
1654 return NULL;
1655 }
1656
1657 /* Called with sessions_mutex held. */
1658 static
1659 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1660 {
1661 struct lttng_kernel_id_tracker *id_tracker = m->private;
1662 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1663 struct lttng_id_hash_node *e;
1664 int iter = 0, i;
1665
1666 (*ppos)++;
1667 if (id_tracker_p) {
1668 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1669 struct hlist_head *head = &id_tracker_p->id_hash[i];
1670
1671 lttng_hlist_for_each_entry(e, head, hlist) {
1672 if (iter++ >= *ppos)
1673 return e;
1674 }
1675 }
1676 } else {
1677 /* ID tracker disabled. */
1678 if (iter >= *ppos && iter == 0)
1679 return p; /* empty tracker */
1680 iter++;
1681 }
1682
1683 /* End of list */
1684 return NULL;
1685 }
1686
1687 static
1688 void id_list_stop(struct seq_file *m, void *p)
1689 {
1690 mutex_unlock(&sessions_mutex);
1691 }
1692
1693 static
1694 int id_list_show(struct seq_file *m, void *p)
1695 {
1696 struct lttng_kernel_id_tracker *id_tracker = m->private;
1697 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1698 int id;
1699
1700 if (p == id_tracker_p) {
1701 /* Tracker disabled. */
1702 id = -1;
1703 } else {
1704 const struct lttng_id_hash_node *e = p;
1705
1706 id = lttng_id_tracker_get_node_id(e);
1707 }
1708 switch (id_tracker->priv->tracker_type) {
1709 case TRACKER_PID:
1710 seq_printf(m, "process { pid = %d; };\n", id);
1711 break;
1712 case TRACKER_VPID:
1713 seq_printf(m, "process { vpid = %d; };\n", id);
1714 break;
1715 case TRACKER_UID:
1716 seq_printf(m, "user { uid = %d; };\n", id);
1717 break;
1718 case TRACKER_VUID:
1719 seq_printf(m, "user { vuid = %d; };\n", id);
1720 break;
1721 case TRACKER_GID:
1722 seq_printf(m, "group { gid = %d; };\n", id);
1723 break;
1724 case TRACKER_VGID:
1725 seq_printf(m, "group { vgid = %d; };\n", id);
1726 break;
1727 default:
1728 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1729 }
1730 return 0;
1731 }
1732
1733 static
1734 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1735 .start = id_list_start,
1736 .next = id_list_next,
1737 .stop = id_list_stop,
1738 .show = id_list_show,
1739 };
1740
1741 static
1742 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1743 {
1744 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1745 }
1746
1747 static
1748 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1749 {
1750 struct seq_file *m = file->private_data;
1751 struct lttng_kernel_id_tracker *id_tracker = m->private;
1752 int ret;
1753
1754 WARN_ON_ONCE(!id_tracker);
1755 ret = seq_release(inode, file);
1756 if (!ret)
1757 fput(id_tracker->priv->session->priv->file);
1758 return ret;
1759 }
1760
1761 const struct file_operations lttng_tracker_ids_list_fops = {
1762 .owner = THIS_MODULE,
1763 .open = lttng_tracker_ids_list_open,
1764 .read = seq_read,
1765 .llseek = seq_lseek,
1766 .release = lttng_tracker_ids_list_release,
1767 };
1768
1769 int lttng_session_list_tracker_ids(struct lttng_kernel_session *session,
1770 enum tracker_type tracker_type)
1771 {
1772 struct file *tracker_ids_list_file;
1773 struct seq_file *m;
1774 int file_fd, ret;
1775
1776 file_fd = lttng_get_unused_fd();
1777 if (file_fd < 0) {
1778 ret = file_fd;
1779 goto fd_error;
1780 }
1781
1782 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1783 &lttng_tracker_ids_list_fops,
1784 NULL, O_RDWR);
1785 if (IS_ERR(tracker_ids_list_file)) {
1786 ret = PTR_ERR(tracker_ids_list_file);
1787 goto file_error;
1788 }
1789 if (!atomic_long_add_unless(&session->priv->file->f_count, 1, LONG_MAX)) {
1790 ret = -EOVERFLOW;
1791 goto refcount_error;
1792 }
1793 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1794 if (ret < 0)
1795 goto open_error;
1796 m = tracker_ids_list_file->private_data;
1797
1798 m->private = get_tracker(session, tracker_type);
1799 BUG_ON(!m->private);
1800 fd_install(file_fd, tracker_ids_list_file);
1801
1802 return file_fd;
1803
1804 open_error:
1805 atomic_long_dec(&session->priv->file->f_count);
1806 refcount_error:
1807 fput(tracker_ids_list_file);
1808 file_error:
1809 put_unused_fd(file_fd);
1810 fd_error:
1811 return ret;
1812 }
1813
1814 /*
1815 * Enabler management.
1816 */
1817 static
1818 int lttng_match_enabler_star_glob(const char *desc_name,
1819 const char *pattern)
1820 {
1821 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1822 desc_name, LTTNG_SIZE_MAX))
1823 return 0;
1824 return 1;
1825 }
1826
1827 static
1828 int lttng_match_enabler_name(const char *desc_name,
1829 const char *name)
1830 {
1831 if (strcmp(desc_name, name))
1832 return 0;
1833 return 1;
1834 }
1835
1836 static
1837 int lttng_desc_match_enabler_check(const struct lttng_kernel_event_desc *desc,
1838 struct lttng_event_enabler_common *enabler)
1839 {
1840 const char *desc_name, *enabler_name;
1841 bool compat = false, entry = false;
1842
1843 enabler_name = enabler->event_param.name;
1844 switch (enabler->event_param.instrumentation) {
1845 case LTTNG_KERNEL_ABI_TRACEPOINT:
1846 desc_name = desc->event_name;
1847 switch (enabler->format_type) {
1848 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1849 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1850 case LTTNG_ENABLER_FORMAT_NAME:
1851 return lttng_match_enabler_name(desc_name, enabler_name);
1852 default:
1853 return -EINVAL;
1854 }
1855 break;
1856
1857 case LTTNG_KERNEL_ABI_SYSCALL:
1858 desc_name = desc->event_name;
1859 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1860 desc_name += strlen("compat_");
1861 compat = true;
1862 }
1863 if (!strncmp(desc_name, "syscall_exit_",
1864 strlen("syscall_exit_"))) {
1865 desc_name += strlen("syscall_exit_");
1866 } else if (!strncmp(desc_name, "syscall_entry_",
1867 strlen("syscall_entry_"))) {
1868 desc_name += strlen("syscall_entry_");
1869 entry = true;
1870 } else {
1871 WARN_ON_ONCE(1);
1872 return -EINVAL;
1873 }
1874 switch (enabler->event_param.u.syscall.entryexit) {
1875 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1876 break;
1877 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1878 if (!entry)
1879 return 0;
1880 break;
1881 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1882 if (entry)
1883 return 0;
1884 break;
1885 default:
1886 return -EINVAL;
1887 }
1888 switch (enabler->event_param.u.syscall.abi) {
1889 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1890 break;
1891 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1892 if (compat)
1893 return 0;
1894 break;
1895 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1896 if (!compat)
1897 return 0;
1898 break;
1899 default:
1900 return -EINVAL;
1901 }
1902 switch (enabler->event_param.u.syscall.match) {
1903 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
1904 switch (enabler->format_type) {
1905 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1906 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1907 case LTTNG_ENABLER_FORMAT_NAME:
1908 return lttng_match_enabler_name(desc_name, enabler_name);
1909 default:
1910 return -EINVAL;
1911 }
1912 break;
1913 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
1914 return -EINVAL; /* Not implemented. */
1915 default:
1916 return -EINVAL;
1917 }
1918 break;
1919
1920 default:
1921 WARN_ON_ONCE(1);
1922 return -EINVAL;
1923 }
1924 }
1925
1926 bool lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
1927 struct lttng_event_enabler_common *enabler)
1928 {
1929 int ret;
1930
1931 ret = lttng_desc_match_enabler_check(desc, enabler);
1932 if (ret < 0) {
1933 WARN_ON_ONCE(1);
1934 return false;
1935 }
1936 return ret;
1937 }
1938
1939 bool lttng_event_enabler_match_event(struct lttng_event_enabler_common *event_enabler,
1940 struct lttng_kernel_event_common *event)
1941 {
1942 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
1943 return false;
1944
1945 switch (event_enabler->enabler_type) {
1946 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
1947 {
1948 struct lttng_event_recorder_enabler *event_recorder_enabler =
1949 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
1950 struct lttng_kernel_event_recorder *event_recorder =
1951 container_of(event, struct lttng_kernel_event_recorder, parent);
1952
1953 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
1954 && event_recorder->chan == event_recorder_enabler->chan)
1955 return true;
1956 else
1957 return false;
1958 }
1959 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
1960 {
1961 struct lttng_event_notifier_enabler *event_notifier_enabler =
1962 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
1963 struct lttng_kernel_event_notifier *event_notifier =
1964 container_of(event, struct lttng_kernel_event_notifier, parent);
1965
1966 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
1967 && event_notifier->priv->group == event_notifier_enabler->group
1968 && event->priv->user_token == event_enabler->user_token)
1969 return true;
1970 else
1971 return false;
1972 }
1973 default:
1974 WARN_ON_ONCE(1);
1975 return false;
1976 }
1977 }
1978
1979 bool lttng_event_enabler_desc_match_event(struct lttng_event_enabler_common *event_enabler,
1980 const struct lttng_kernel_event_desc *desc,
1981 struct lttng_kernel_event_common *event)
1982 {
1983 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
1984 return false;
1985
1986 switch (event_enabler->enabler_type) {
1987 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
1988 {
1989 struct lttng_event_recorder_enabler *event_recorder_enabler =
1990 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
1991 struct lttng_kernel_event_recorder *event_recorder =
1992 container_of(event, struct lttng_kernel_event_recorder, parent);
1993
1994 if (event->priv->desc == desc && event_recorder->chan == event_recorder_enabler->chan)
1995 return true;
1996 else
1997 return false;
1998 }
1999 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2000 {
2001 struct lttng_event_notifier_enabler *event_notifier_enabler =
2002 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2003 struct lttng_kernel_event_notifier *event_notifier =
2004 container_of(event, struct lttng_kernel_event_notifier, parent);
2005
2006 if (event->priv->desc == desc
2007 && event_notifier->priv->group == event_notifier_enabler->group
2008 && event->priv->user_token == event_enabler->user_token)
2009 return true;
2010 else
2011 return false;
2012 }
2013 default:
2014 WARN_ON_ONCE(1);
2015 return false;
2016 }
2017 }
2018
2019 bool lttng_event_enabler_event_name_match_event(struct lttng_event_enabler_common *event_enabler,
2020 const char *event_name,
2021 struct lttng_kernel_event_common *event)
2022 {
2023 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2024 return false;
2025
2026 switch (event_enabler->enabler_type) {
2027 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2028 {
2029 struct lttng_event_recorder_enabler *event_recorder_enabler =
2030 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2031 struct lttng_kernel_event_recorder *event_recorder =
2032 container_of(event, struct lttng_kernel_event_recorder, parent);
2033
2034 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2035 && event_recorder->chan == event_recorder_enabler->chan)
2036 return true;
2037 else
2038 return false;
2039 }
2040 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2041 {
2042 struct lttng_event_notifier_enabler *event_notifier_enabler =
2043 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2044 struct lttng_kernel_event_notifier *event_notifier =
2045 container_of(event, struct lttng_kernel_event_notifier, parent);
2046
2047 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2048 && event_notifier->priv->group == event_notifier_enabler->group
2049 && event->priv->user_token == event_enabler->user_token)
2050 return true;
2051 else
2052 return false;
2053 }
2054 default:
2055 WARN_ON_ONCE(1);
2056 return false;
2057 }
2058 }
2059
2060 static
2061 struct lttng_enabler_ref *lttng_enabler_ref(
2062 struct list_head *enablers_ref_list,
2063 struct lttng_event_enabler_common *enabler)
2064 {
2065 struct lttng_enabler_ref *enabler_ref;
2066
2067 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2068 if (enabler_ref->ref == enabler)
2069 return enabler_ref;
2070 }
2071 return NULL;
2072 }
2073
2074 static
2075 void lttng_event_enabler_create_tracepoint_events_if_missing(struct lttng_event_enabler_common *event_enabler)
2076 {
2077 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(event_enabler);
2078 struct lttng_kernel_probe_desc *probe_desc;
2079 const struct lttng_kernel_event_desc *desc;
2080 struct list_head *probe_list;
2081 int i;
2082
2083 probe_list = lttng_get_probe_list_head();
2084 /*
2085 * For each probe event, if we find that a probe event matches
2086 * our enabler, create an associated lttng_event if not
2087 * already present.
2088 */
2089 list_for_each_entry(probe_desc, probe_list, head) {
2090 for (i = 0; i < probe_desc->nr_events; i++) {
2091 bool found = false;
2092 struct hlist_head *head;
2093 struct lttng_kernel_event_common *event;
2094 struct lttng_kernel_event_common_private *event_priv;
2095
2096 desc = probe_desc->event_desc[i];
2097 if (!lttng_desc_match_enabler(desc, event_enabler))
2098 continue;
2099
2100 /*
2101 * Check if already created.
2102 */
2103 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
2104 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
2105 if (lttng_event_enabler_desc_match_event(event_enabler, desc, event_priv->pub)) {
2106 found = true;
2107 break;
2108 }
2109 }
2110 if (found)
2111 continue;
2112
2113 /*
2114 * We need to create an event for this event probe.
2115 */
2116 event = _lttng_kernel_event_create(event_enabler, desc);
2117 if (IS_ERR(event)) {
2118 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2119 probe_desc->event_desc[i]->event_name);
2120 }
2121 }
2122 }
2123 }
2124
2125 /*
2126 * Create event if it is missing and present in the list of tracepoint probes.
2127 * Should be called with sessions mutex held.
2128 */
2129 static
2130 void lttng_event_enabler_create_events_if_missing(struct lttng_event_enabler_common *event_enabler)
2131 {
2132 int ret;
2133
2134 switch (event_enabler->event_param.instrumentation) {
2135 case LTTNG_KERNEL_ABI_TRACEPOINT:
2136 lttng_event_enabler_create_tracepoint_events_if_missing(event_enabler);
2137 break;
2138
2139 case LTTNG_KERNEL_ABI_SYSCALL:
2140 ret = lttng_event_enabler_create_syscall_events_if_missing(event_enabler);
2141 WARN_ON_ONCE(ret);
2142 break;
2143
2144 default:
2145 WARN_ON_ONCE(1);
2146 break;
2147 }
2148 }
2149
2150 static
2151 void lttng_event_enabler_init_event_filter(struct lttng_event_enabler_common *event_enabler,
2152 struct lttng_kernel_event_common *event)
2153 {
2154 /* Link filter bytecodes if not linked yet. */
2155 lttng_enabler_link_bytecode(event->priv->desc, lttng_static_ctx,
2156 &event->priv->filter_bytecode_runtime_head, &event_enabler->filter_bytecode_head);
2157 }
2158
2159 static
2160 void lttng_event_enabler_init_event_capture(struct lttng_event_enabler_common *event_enabler,
2161 struct lttng_kernel_event_common *event)
2162 {
2163 switch (event_enabler->enabler_type) {
2164 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2165 break;
2166 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2167 {
2168 struct lttng_event_notifier_enabler *event_notifier_enabler =
2169 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2170 struct lttng_kernel_event_notifier *event_notifier =
2171 container_of(event, struct lttng_kernel_event_notifier, parent);
2172
2173 /* Link capture bytecodes if not linked yet. */
2174 lttng_enabler_link_bytecode(event->priv->desc,
2175 lttng_static_ctx, &event_notifier->priv->capture_bytecode_runtime_head,
2176 &event_notifier_enabler->capture_bytecode_head);
2177 event_notifier->priv->num_captures = event_notifier_enabler->num_captures;
2178 break;
2179 }
2180 default:
2181 WARN_ON_ONCE(1);
2182 }
2183 }
2184
2185 /*
2186 * Create events associated with an event_enabler (if not already present),
2187 * and add backward reference from the event to the enabler.
2188 * Should be called with sessions mutex held.
2189 */
2190 static
2191 int lttng_event_enabler_ref_events(struct lttng_event_enabler_common *event_enabler)
2192 {
2193 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(event_enabler);
2194 struct lttng_kernel_event_common_private *event_priv;
2195
2196 lttng_syscall_table_set_wildcard_all(event_enabler);
2197
2198 /* First ensure that probe events are created for this enabler. */
2199 lttng_event_enabler_create_events_if_missing(event_enabler);
2200
2201 /* Link the created event with its associated enabler. */
2202 list_for_each_entry(event_priv, event_list_head, node) {
2203 struct lttng_kernel_event_common *event = event_priv->pub;
2204 struct lttng_enabler_ref *enabler_ref;
2205
2206 if (!lttng_event_enabler_match_event(event_enabler, event))
2207 continue;
2208
2209 enabler_ref = lttng_enabler_ref(&event_priv->enablers_ref_head, event_enabler);
2210 if (!enabler_ref) {
2211 /*
2212 * If no backward ref, create it.
2213 * Add backward ref from event_notifier to enabler.
2214 */
2215 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2216 if (!enabler_ref)
2217 return -ENOMEM;
2218
2219 enabler_ref->ref = event_enabler;
2220 list_add(&enabler_ref->node, &event_priv->enablers_ref_head);
2221 }
2222
2223 lttng_event_enabler_init_event_filter(event_enabler, event);
2224 lttng_event_enabler_init_event_capture(event_enabler, event);
2225 }
2226 return 0;
2227 }
2228
2229 /*
2230 * Called at module load: connect the probe on all enablers matching
2231 * this event.
2232 * Called with sessions lock held.
2233 */
2234 int lttng_fix_pending_events(void)
2235 {
2236 struct lttng_kernel_session_private *session_priv;
2237
2238 list_for_each_entry(session_priv, &sessions, list)
2239 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2240 return 0;
2241 }
2242
2243 static bool lttng_event_notifier_group_has_active_event_notifiers(
2244 struct lttng_event_notifier_group *event_notifier_group)
2245 {
2246 struct lttng_event_enabler_common *event_enabler;
2247
2248 list_for_each_entry(event_enabler, &event_notifier_group->enablers_head, node) {
2249 if (event_enabler->enabled)
2250 return true;
2251 }
2252 return false;
2253 }
2254
2255 bool lttng_event_notifier_active(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 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2261 return true;
2262 }
2263 return false;
2264 }
2265
2266 int lttng_fix_pending_event_notifiers(void)
2267 {
2268 struct lttng_event_notifier_group *event_notifier_group;
2269
2270 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2271 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2272 return 0;
2273 }
2274
2275 struct lttng_event_recorder_enabler *lttng_event_recorder_enabler_create(
2276 enum lttng_enabler_format_type format_type,
2277 struct lttng_kernel_abi_event *event_param,
2278 struct lttng_kernel_channel_buffer *chan)
2279 {
2280 struct lttng_event_recorder_enabler *event_enabler;
2281
2282 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2283 if (!event_enabler)
2284 return NULL;
2285 event_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_RECORDER;
2286 event_enabler->parent.format_type = format_type;
2287 INIT_LIST_HEAD(&event_enabler->parent.filter_bytecode_head);
2288 memcpy(&event_enabler->parent.event_param, event_param,
2289 sizeof(event_enabler->parent.event_param));
2290 event_enabler->chan = chan;
2291 /* ctx left NULL */
2292 event_enabler->parent.enabled = 0;
2293 return event_enabler;
2294 }
2295
2296 void lttng_event_enabler_session_add(struct lttng_kernel_session *session,
2297 struct lttng_event_recorder_enabler *event_enabler)
2298 {
2299 mutex_lock(&sessions_mutex);
2300 list_add(&event_enabler->parent.node, &session->priv->enablers_head);
2301 event_enabler->parent.published = true;
2302 lttng_session_lazy_sync_event_enablers(session);
2303 mutex_unlock(&sessions_mutex);
2304 }
2305
2306 int lttng_event_enabler_enable(struct lttng_event_enabler_common *event_enabler)
2307 {
2308 mutex_lock(&sessions_mutex);
2309 event_enabler->enabled = 1;
2310 lttng_event_enabler_sync(event_enabler);
2311 mutex_unlock(&sessions_mutex);
2312 return 0;
2313 }
2314
2315 int lttng_event_enabler_disable(struct lttng_event_enabler_common *event_enabler)
2316 {
2317 mutex_lock(&sessions_mutex);
2318 event_enabler->enabled = 0;
2319 lttng_event_enabler_sync(event_enabler);
2320 mutex_unlock(&sessions_mutex);
2321 return 0;
2322 }
2323
2324 static
2325 int lttng_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *enabler,
2326 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2327 {
2328 struct lttng_kernel_bytecode_node *bytecode_node;
2329 uint32_t bytecode_len;
2330 int ret;
2331
2332 ret = get_user(bytecode_len, &bytecode->len);
2333 if (ret)
2334 return ret;
2335 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2336 GFP_KERNEL);
2337 if (!bytecode_node)
2338 return -ENOMEM;
2339 ret = copy_from_user(&bytecode_node->bc, bytecode,
2340 sizeof(*bytecode) + bytecode_len);
2341 if (ret)
2342 goto error_free;
2343
2344 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2345 bytecode_node->enabler = enabler;
2346 /* Enforce length based on allocated size */
2347 bytecode_node->bc.len = bytecode_len;
2348 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2349
2350 return 0;
2351
2352 error_free:
2353 lttng_kvfree(bytecode_node);
2354 return ret;
2355 }
2356
2357 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *event_enabler,
2358 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2359 {
2360 int ret;
2361 ret = lttng_enabler_attach_filter_bytecode(event_enabler, bytecode);
2362 if (ret)
2363 goto error;
2364 lttng_event_enabler_sync(event_enabler);
2365 return 0;
2366
2367 error:
2368 return ret;
2369 }
2370
2371 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2372 struct lttng_kernel_abi_event_callsite __user *callsite)
2373 {
2374
2375 switch (event->priv->instrumentation) {
2376 case LTTNG_KERNEL_ABI_UPROBE:
2377 return lttng_uprobes_event_add_callsite(event, callsite);
2378 default:
2379 return -EINVAL;
2380 }
2381 }
2382
2383 static
2384 void lttng_enabler_destroy(struct lttng_event_enabler_common *enabler)
2385 {
2386 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2387
2388 /* Destroy filter bytecode */
2389 list_for_each_entry_safe(filter_node, tmp_filter_node,
2390 &enabler->filter_bytecode_head, node) {
2391 lttng_kvfree(filter_node);
2392 }
2393 }
2394
2395 void lttng_event_enabler_destroy(struct lttng_event_enabler_common *event_enabler)
2396 {
2397 lttng_enabler_destroy(event_enabler);
2398 if (event_enabler->published)
2399 list_del(&event_enabler->node);
2400
2401 switch (event_enabler->enabler_type) {
2402 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2403 {
2404 struct lttng_event_recorder_enabler *event_recorder_enabler =
2405 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2406
2407 kfree(event_recorder_enabler);
2408 break;
2409 }
2410 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2411 {
2412 struct lttng_event_notifier_enabler *event_notifier_enabler =
2413 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2414
2415 kfree(event_notifier_enabler);
2416 break;
2417 }
2418 default:
2419 WARN_ON_ONCE(1);
2420 }
2421 }
2422
2423 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2424 enum lttng_enabler_format_type format_type,
2425 struct lttng_kernel_abi_event_notifier *event_notifier_param,
2426 struct lttng_event_notifier_group *event_notifier_group)
2427 {
2428 struct lttng_event_notifier_enabler *event_notifier_enabler;
2429
2430 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2431 if (!event_notifier_enabler)
2432 return NULL;
2433
2434 event_notifier_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_NOTIFIER;
2435 event_notifier_enabler->parent.format_type = format_type;
2436 INIT_LIST_HEAD(&event_notifier_enabler->parent.filter_bytecode_head);
2437 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2438
2439 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2440 event_notifier_enabler->num_captures = 0;
2441
2442 memcpy(&event_notifier_enabler->parent.event_param, &event_notifier_param->event,
2443 sizeof(event_notifier_enabler->parent.event_param));
2444
2445 event_notifier_enabler->parent.enabled = 0;
2446 event_notifier_enabler->parent.user_token = event_notifier_param->event.token;
2447 event_notifier_enabler->group = event_notifier_group;
2448 return event_notifier_enabler;
2449 }
2450
2451 void lttng_event_notifier_enabler_group_add(struct lttng_event_notifier_group *event_notifier_group,
2452 struct lttng_event_notifier_enabler *event_notifier_enabler)
2453 {
2454 mutex_lock(&sessions_mutex);
2455 list_add(&event_notifier_enabler->parent.node, &event_notifier_enabler->group->enablers_head);
2456 event_notifier_enabler->parent.published = true;
2457 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2458 mutex_unlock(&sessions_mutex);
2459 }
2460
2461 int lttng_event_notifier_enabler_enable(
2462 struct lttng_event_notifier_enabler *event_notifier_enabler)
2463 {
2464 mutex_lock(&sessions_mutex);
2465 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2466 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2467 mutex_unlock(&sessions_mutex);
2468 return 0;
2469 }
2470
2471 int lttng_event_notifier_enabler_disable(
2472 struct lttng_event_notifier_enabler *event_notifier_enabler)
2473 {
2474 mutex_lock(&sessions_mutex);
2475 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2476 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2477 mutex_unlock(&sessions_mutex);
2478 return 0;
2479 }
2480
2481 int lttng_event_notifier_enabler_attach_capture_bytecode(
2482 struct lttng_event_notifier_enabler *event_notifier_enabler,
2483 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2484 {
2485 struct lttng_kernel_bytecode_node *bytecode_node;
2486 struct lttng_event_enabler_common *enabler =
2487 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2488 uint32_t bytecode_len;
2489 int ret;
2490
2491 ret = get_user(bytecode_len, &bytecode->len);
2492 if (ret)
2493 return ret;
2494
2495 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2496 GFP_KERNEL);
2497 if (!bytecode_node)
2498 return -ENOMEM;
2499
2500 ret = copy_from_user(&bytecode_node->bc, bytecode,
2501 sizeof(*bytecode) + bytecode_len);
2502 if (ret)
2503 goto error_free;
2504
2505 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2506 bytecode_node->enabler = enabler;
2507
2508 /* Enforce length based on allocated size */
2509 bytecode_node->bc.len = bytecode_len;
2510 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2511
2512 event_notifier_enabler->num_captures++;
2513
2514 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2515 goto end;
2516
2517 error_free:
2518 lttng_kvfree(bytecode_node);
2519 end:
2520 return ret;
2521 }
2522
2523 static
2524 void lttng_event_sync_filter_state(struct lttng_kernel_event_common *event)
2525 {
2526 int has_enablers_without_filter_bytecode = 0, nr_filters = 0;
2527 struct lttng_kernel_bytecode_runtime *runtime;
2528 struct lttng_enabler_ref *enabler_ref;
2529
2530 /* Check if has enablers without bytecode enabled */
2531 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2532 if (enabler_ref->ref->enabled
2533 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2534 has_enablers_without_filter_bytecode = 1;
2535 break;
2536 }
2537 }
2538 event->priv->has_enablers_without_filter_bytecode = has_enablers_without_filter_bytecode;
2539
2540 /* Enable filters */
2541 list_for_each_entry(runtime, &event->priv->filter_bytecode_runtime_head, node) {
2542 lttng_bytecode_sync_state(runtime);
2543 nr_filters++;
2544 }
2545 WRITE_ONCE(event->eval_filter, !(has_enablers_without_filter_bytecode || !nr_filters));
2546 }
2547
2548 static
2549 void lttng_event_sync_capture_state(struct lttng_kernel_event_common *event)
2550 {
2551 switch (event->type) {
2552 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2553 break;
2554 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2555 {
2556 struct lttng_kernel_event_notifier *event_notifier =
2557 container_of(event, struct lttng_kernel_event_notifier, parent);
2558 struct lttng_kernel_bytecode_runtime *runtime;
2559 int nr_captures = 0;
2560
2561 /* Enable captures */
2562 list_for_each_entry(runtime, &event_notifier->priv->capture_bytecode_runtime_head, node) {
2563 lttng_bytecode_sync_state(runtime);
2564 nr_captures++;
2565 }
2566 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2567 break;
2568 }
2569 default:
2570 WARN_ON_ONCE(1);
2571 }
2572 }
2573
2574 static
2575 bool lttng_get_event_enabled_state(struct lttng_kernel_event_common *event)
2576 {
2577 struct lttng_enabler_ref *enabler_ref;
2578 bool enabled = false;
2579
2580 switch (event->priv->instrumentation) {
2581 case LTTNG_KERNEL_ABI_TRACEPOINT:
2582 lttng_fallthrough;
2583 case LTTNG_KERNEL_ABI_SYSCALL:
2584 /* Enable events */
2585 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2586 if (enabler_ref->ref->enabled) {
2587 enabled = true;
2588 break;
2589 }
2590 }
2591 break;
2592 default:
2593 WARN_ON_ONCE(1);
2594 return false;
2595 }
2596
2597 switch (event->type) {
2598 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2599 {
2600 struct lttng_kernel_event_recorder *event_recorder =
2601 container_of(event, struct lttng_kernel_event_recorder, parent);
2602
2603 /*
2604 * Enabled state is based on union of enablers, with
2605 * intersection of session and channel transient enable
2606 * states.
2607 */
2608 return enabled && event_recorder->chan->parent.session->priv->tstate && event_recorder->chan->priv->parent.tstate;
2609 }
2610 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2611 return enabled;
2612 default:
2613 WARN_ON_ONCE(1);
2614 return false;
2615 }
2616 }
2617
2618 static
2619 bool lttng_event_is_lazy_sync(struct lttng_kernel_event_common *event)
2620 {
2621 switch (event->priv->instrumentation) {
2622 case LTTNG_KERNEL_ABI_TRACEPOINT:
2623 lttng_fallthrough;
2624 case LTTNG_KERNEL_ABI_SYSCALL:
2625 return true;
2626
2627 default:
2628 /* Not handled with lazy sync. */
2629 return false;
2630 }
2631 }
2632
2633 /*
2634 * Should be called with sessions mutex held.
2635 */
2636 static
2637 void lttng_sync_event_list(struct list_head *event_enabler_list,
2638 struct list_head *event_list)
2639 {
2640 struct lttng_kernel_event_common_private *event_priv;
2641 struct lttng_event_enabler_common *event_enabler;
2642
2643 list_for_each_entry(event_enabler, event_enabler_list, node)
2644 lttng_event_enabler_ref_events(event_enabler);
2645
2646 /*
2647 * For each event, if at least one of its enablers is enabled,
2648 * and its channel and session transient states are enabled, we
2649 * enable the event, else we disable it.
2650 */
2651 list_for_each_entry(event_priv, event_list, node) {
2652 struct lttng_kernel_event_common *event = event_priv->pub;
2653 bool enabled;
2654
2655 if (!lttng_event_is_lazy_sync(event))
2656 continue;
2657
2658 enabled = lttng_get_event_enabled_state(event);
2659 WRITE_ONCE(event->enabled, enabled);
2660 /*
2661 * Sync tracepoint registration with event enabled state.
2662 */
2663 if (enabled) {
2664 if (!event_priv->registered)
2665 register_event(event);
2666 } else {
2667 if (event_priv->registered)
2668 unregister_event(event);
2669 }
2670
2671 lttng_event_sync_filter_state(event);
2672 lttng_event_sync_capture_state(event);
2673 }
2674 }
2675
2676 /*
2677 * lttng_session_sync_event_enablers should be called just before starting a
2678 * session.
2679 */
2680 static
2681 void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2682 {
2683 lttng_sync_event_list(&session->priv->enablers_head, &session->priv->events);
2684 }
2685
2686 /*
2687 * Apply enablers to session events, adding events to session if need
2688 * be. It is required after each modification applied to an active
2689 * session, and right before session "start".
2690 * "lazy" sync means we only sync if required.
2691 * Should be called with sessions mutex held.
2692 */
2693 static
2694 void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2695 {
2696 /* We can skip if session is not active */
2697 if (!session->active)
2698 return;
2699 lttng_session_sync_event_enablers(session);
2700 }
2701
2702 static
2703 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2704 {
2705 lttng_sync_event_list(&event_notifier_group->enablers_head, &event_notifier_group->event_notifiers_head);
2706 }
2707
2708 static
2709 void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler)
2710 {
2711 switch (event_enabler->enabler_type) {
2712 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2713 {
2714 struct lttng_event_recorder_enabler *event_recorder_enabler =
2715 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2716 lttng_session_lazy_sync_event_enablers(event_recorder_enabler->chan->parent.session);
2717 break;
2718 }
2719 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2720 {
2721 struct lttng_event_notifier_enabler *event_notifier_enabler =
2722 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2723 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2724 break;
2725 }
2726 default:
2727 WARN_ON_ONCE(1);
2728 }
2729 }
2730
2731 /*
2732 * Serialize at most one packet worth of metadata into a metadata
2733 * channel.
2734 * We grab the metadata cache mutex to get exclusive access to our metadata
2735 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2736 * allows us to do racy operations such as looking for remaining space left in
2737 * packet and write, since mutual exclusion protects us from concurrent writes.
2738 * Mutual exclusion on the metadata cache allow us to read the cache content
2739 * without racing against reallocation of the cache by updates.
2740 * Returns the number of bytes written in the channel, 0 if no data
2741 * was written and a negative value on error.
2742 */
2743 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2744 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2745 {
2746 struct lttng_kernel_ring_buffer_ctx ctx;
2747 int ret = 0;
2748 size_t len, reserve_len;
2749
2750 /*
2751 * Ensure we support mutiple get_next / put sequences followed by
2752 * put_next. The metadata cache lock protects reading the metadata
2753 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2754 * "flush" operations on the buffer invoked by different processes.
2755 * Moreover, since the metadata cache memory can be reallocated, we
2756 * need to have exclusive access against updates even though we only
2757 * read it.
2758 */
2759 mutex_lock(&stream->metadata_cache->lock);
2760 WARN_ON(stream->metadata_in < stream->metadata_out);
2761 if (stream->metadata_in != stream->metadata_out)
2762 goto end;
2763
2764 /* Metadata regenerated, change the version. */
2765 if (stream->metadata_cache->version != stream->version)
2766 stream->version = stream->metadata_cache->version;
2767
2768 len = stream->metadata_cache->metadata_written -
2769 stream->metadata_in;
2770 if (!len)
2771 goto end;
2772 reserve_len = min_t(size_t,
2773 stream->transport->ops.priv->packet_avail_size(chan),
2774 len);
2775 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2776 sizeof(char), NULL);
2777 /*
2778 * If reservation failed, return an error to the caller.
2779 */
2780 ret = stream->transport->ops.event_reserve(&ctx);
2781 if (ret != 0) {
2782 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2783 stream->coherent = false;
2784 goto end;
2785 }
2786 stream->transport->ops.event_write(&ctx,
2787 stream->metadata_cache->data + stream->metadata_in,
2788 reserve_len, 1);
2789 stream->transport->ops.event_commit(&ctx);
2790 stream->metadata_in += reserve_len;
2791 if (reserve_len < len)
2792 stream->coherent = false;
2793 else
2794 stream->coherent = true;
2795 ret = reserve_len;
2796
2797 end:
2798 if (coherent)
2799 *coherent = stream->coherent;
2800 mutex_unlock(&stream->metadata_cache->lock);
2801 return ret;
2802 }
2803
2804 static
2805 void lttng_metadata_begin(struct lttng_kernel_session *session)
2806 {
2807 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
2808 mutex_lock(&session->priv->metadata_cache->lock);
2809 }
2810
2811 static
2812 void lttng_metadata_end(struct lttng_kernel_session *session)
2813 {
2814 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2815 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
2816 struct lttng_metadata_stream *stream;
2817
2818 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
2819 wake_up_interruptible(&stream->read_wait);
2820 mutex_unlock(&session->priv->metadata_cache->lock);
2821 }
2822 }
2823
2824 /*
2825 * Write the metadata to the metadata cache.
2826 * Must be called with sessions_mutex held.
2827 * The metadata cache lock protects us from concurrent read access from
2828 * thread outputting metadata content to ring buffer.
2829 * The content of the printf is printed as a single atomic metadata
2830 * transaction.
2831 */
2832 int lttng_metadata_printf(struct lttng_kernel_session *session,
2833 const char *fmt, ...)
2834 {
2835 char *str;
2836 size_t len;
2837 va_list ap;
2838
2839 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2840
2841 va_start(ap, fmt);
2842 str = kvasprintf(GFP_KERNEL, fmt, ap);
2843 va_end(ap);
2844 if (!str)
2845 return -ENOMEM;
2846
2847 len = strlen(str);
2848 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2849 if (session->priv->metadata_cache->metadata_written + len >
2850 session->priv->metadata_cache->cache_alloc) {
2851 char *tmp_cache_realloc;
2852 unsigned int tmp_cache_alloc_size;
2853
2854 tmp_cache_alloc_size = max_t(unsigned int,
2855 session->priv->metadata_cache->cache_alloc + len,
2856 session->priv->metadata_cache->cache_alloc << 1);
2857 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2858 if (!tmp_cache_realloc)
2859 goto err;
2860 if (session->priv->metadata_cache->data) {
2861 memcpy(tmp_cache_realloc,
2862 session->priv->metadata_cache->data,
2863 session->priv->metadata_cache->cache_alloc);
2864 vfree(session->priv->metadata_cache->data);
2865 }
2866
2867 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2868 session->priv->metadata_cache->data = tmp_cache_realloc;
2869 }
2870 memcpy(session->priv->metadata_cache->data +
2871 session->priv->metadata_cache->metadata_written,
2872 str, len);
2873 session->priv->metadata_cache->metadata_written += len;
2874 kfree(str);
2875
2876 return 0;
2877
2878 err:
2879 kfree(str);
2880 return -ENOMEM;
2881 }
2882
2883 static
2884 int print_tabs(struct lttng_kernel_session *session, size_t nesting)
2885 {
2886 size_t i;
2887
2888 for (i = 0; i < nesting; i++) {
2889 int ret;
2890
2891 ret = lttng_metadata_printf(session, " ");
2892 if (ret) {
2893 return ret;
2894 }
2895 }
2896 return 0;
2897 }
2898
2899 static
2900 int lttng_field_name_statedump(struct lttng_kernel_session *session,
2901 const struct lttng_kernel_event_field *field,
2902 size_t nesting)
2903 {
2904 return lttng_metadata_printf(session, " _%s;\n", field->name);
2905 }
2906
2907 static
2908 int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
2909 const struct lttng_kernel_type_integer *type,
2910 enum lttng_kernel_string_encoding parent_encoding,
2911 size_t nesting)
2912 {
2913 int ret;
2914
2915 ret = print_tabs(session, nesting);
2916 if (ret)
2917 return ret;
2918 ret = lttng_metadata_printf(session,
2919 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
2920 type->size,
2921 type->alignment,
2922 type->signedness,
2923 (parent_encoding == lttng_kernel_string_encoding_none)
2924 ? "none"
2925 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
2926 ? "UTF8"
2927 : "ASCII",
2928 type->base,
2929 #if __BYTE_ORDER == __BIG_ENDIAN
2930 type->reverse_byte_order ? " byte_order = le;" : ""
2931 #else
2932 type->reverse_byte_order ? " byte_order = be;" : ""
2933 #endif
2934 );
2935 return ret;
2936 }
2937
2938 /*
2939 * Must be called with sessions_mutex held.
2940 */
2941 static
2942 int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
2943 const struct lttng_kernel_type_struct *type,
2944 size_t nesting)
2945 {
2946 const char *prev_field_name = NULL;
2947 int ret;
2948 uint32_t i, nr_fields;
2949 unsigned int alignment;
2950
2951 ret = print_tabs(session, nesting);
2952 if (ret)
2953 return ret;
2954 ret = lttng_metadata_printf(session,
2955 "struct {\n");
2956 if (ret)
2957 return ret;
2958 nr_fields = type->nr_fields;
2959 for (i = 0; i < nr_fields; i++) {
2960 const struct lttng_kernel_event_field *iter_field;
2961
2962 iter_field = type->fields[i];
2963 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
2964 if (ret)
2965 return ret;
2966 }
2967 ret = print_tabs(session, nesting);
2968 if (ret)
2969 return ret;
2970 alignment = type->alignment;
2971 if (alignment) {
2972 ret = lttng_metadata_printf(session,
2973 "} align(%u)",
2974 alignment);
2975 } else {
2976 ret = lttng_metadata_printf(session,
2977 "}");
2978 }
2979 return ret;
2980 }
2981
2982 /*
2983 * Must be called with sessions_mutex held.
2984 */
2985 static
2986 int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
2987 const struct lttng_kernel_event_field *field,
2988 size_t nesting)
2989 {
2990 int ret;
2991
2992 ret = _lttng_struct_type_statedump(session,
2993 lttng_kernel_get_type_struct(field->type), nesting);
2994 if (ret)
2995 return ret;
2996 return lttng_field_name_statedump(session, field, nesting);
2997 }
2998
2999 /*
3000 * Must be called with sessions_mutex held.
3001 */
3002 static
3003 int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
3004 const struct lttng_kernel_type_variant *type,
3005 size_t nesting,
3006 const char *prev_field_name)
3007 {
3008 const char *tag_name;
3009 int ret;
3010 uint32_t i, nr_choices;
3011
3012 tag_name = type->tag_name;
3013 if (!tag_name)
3014 tag_name = prev_field_name;
3015 if (!tag_name)
3016 return -EINVAL;
3017 /*
3018 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3019 */
3020 if (type->alignment != 0)
3021 return -EINVAL;
3022 ret = print_tabs(session, nesting);
3023 if (ret)
3024 return ret;
3025 ret = lttng_metadata_printf(session,
3026 "variant <_%s> {\n",
3027 tag_name);
3028 if (ret)
3029 return ret;
3030 nr_choices = type->nr_choices;
3031 for (i = 0; i < nr_choices; i++) {
3032 const struct lttng_kernel_event_field *iter_field;
3033
3034 iter_field = type->choices[i];
3035 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3036 if (ret)
3037 return ret;
3038 }
3039 ret = print_tabs(session, nesting);
3040 if (ret)
3041 return ret;
3042 ret = lttng_metadata_printf(session,
3043 "}");
3044 return ret;
3045 }
3046
3047 /*
3048 * Must be called with sessions_mutex held.
3049 */
3050 static
3051 int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3052 const struct lttng_kernel_event_field *field,
3053 size_t nesting,
3054 const char *prev_field_name)
3055 {
3056 int ret;
3057
3058 ret = _lttng_variant_type_statedump(session,
3059 lttng_kernel_get_type_variant(field->type), nesting,
3060 prev_field_name);
3061 if (ret)
3062 return ret;
3063 return lttng_field_name_statedump(session, field, nesting);
3064 }
3065
3066 /*
3067 * Must be called with sessions_mutex held.
3068 */
3069 static
3070 int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3071 const struct lttng_kernel_event_field *field,
3072 size_t nesting)
3073 {
3074 int ret;
3075 const struct lttng_kernel_type_array *array_type;
3076 const struct lttng_kernel_type_common *elem_type;
3077
3078 array_type = lttng_kernel_get_type_array(field->type);
3079 WARN_ON_ONCE(!array_type);
3080
3081 if (array_type->alignment) {
3082 ret = print_tabs(session, nesting);
3083 if (ret)
3084 return ret;
3085 ret = lttng_metadata_printf(session,
3086 "struct { } align(%u) _%s_padding;\n",
3087 array_type->alignment * CHAR_BIT,
3088 field->name);
3089 if (ret)
3090 return ret;
3091 }
3092 /*
3093 * Nested compound types: Only array of structures and variants are
3094 * currently supported.
3095 */
3096 elem_type = array_type->elem_type;
3097 switch (elem_type->type) {
3098 case lttng_kernel_type_integer:
3099 case lttng_kernel_type_struct:
3100 case lttng_kernel_type_variant:
3101 ret = _lttng_type_statedump(session, elem_type,
3102 array_type->encoding, nesting);
3103 if (ret)
3104 return ret;
3105 break;
3106
3107 default:
3108 return -EINVAL;
3109 }
3110 ret = lttng_metadata_printf(session,
3111 " _%s[%u];\n",
3112 field->name,
3113 array_type->length);
3114 return ret;
3115 }
3116
3117 /*
3118 * Must be called with sessions_mutex held.
3119 */
3120 static
3121 int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3122 const struct lttng_kernel_event_field *field,
3123 size_t nesting,
3124 const char *prev_field_name)
3125 {
3126 int ret;
3127 const char *length_name;
3128 const struct lttng_kernel_type_sequence *sequence_type;
3129 const struct lttng_kernel_type_common *elem_type;
3130
3131 sequence_type = lttng_kernel_get_type_sequence(field->type);
3132 WARN_ON_ONCE(!sequence_type);
3133
3134 length_name = sequence_type->length_name;
3135 if (!length_name)
3136 length_name = prev_field_name;
3137 if (!length_name)
3138 return -EINVAL;
3139
3140 if (sequence_type->alignment) {
3141 ret = print_tabs(session, nesting);
3142 if (ret)
3143 return ret;
3144 ret = lttng_metadata_printf(session,
3145 "struct { } align(%u) _%s_padding;\n",
3146 sequence_type->alignment * CHAR_BIT,
3147 field->name);
3148 if (ret)
3149 return ret;
3150 }
3151
3152 /*
3153 * Nested compound types: Only array of structures and variants are
3154 * currently supported.
3155 */
3156 elem_type = sequence_type->elem_type;
3157 switch (elem_type->type) {
3158 case lttng_kernel_type_integer:
3159 case lttng_kernel_type_struct:
3160 case lttng_kernel_type_variant:
3161 ret = _lttng_type_statedump(session, elem_type,
3162 sequence_type->encoding, nesting);
3163 if (ret)
3164 return ret;
3165 break;
3166
3167 default:
3168 return -EINVAL;
3169 }
3170 ret = lttng_metadata_printf(session,
3171 " _%s[ _%s ];\n",
3172 field->name,
3173 length_name);
3174 return ret;
3175 }
3176
3177 /*
3178 * Must be called with sessions_mutex held.
3179 */
3180 static
3181 int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3182 const struct lttng_kernel_type_enum *type,
3183 size_t nesting)
3184 {
3185 const struct lttng_kernel_enum_desc *enum_desc;
3186 const struct lttng_kernel_type_common *container_type;
3187 int ret;
3188 unsigned int i, nr_entries;
3189
3190 container_type = type->container_type;
3191 if (container_type->type != lttng_kernel_type_integer) {
3192 ret = -EINVAL;
3193 goto end;
3194 }
3195 enum_desc = type->desc;
3196 nr_entries = enum_desc->nr_entries;
3197
3198 ret = print_tabs(session, nesting);
3199 if (ret)
3200 goto end;
3201 ret = lttng_metadata_printf(session, "enum : ");
3202 if (ret)
3203 goto end;
3204 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3205 lttng_kernel_string_encoding_none, 0);
3206 if (ret)
3207 goto end;
3208 ret = lttng_metadata_printf(session, " {\n");
3209 if (ret)
3210 goto end;
3211 /* Dump all entries */
3212 for (i = 0; i < nr_entries; i++) {
3213 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3214 int j, len;
3215
3216 ret = print_tabs(session, nesting + 1);
3217 if (ret)
3218 goto end;
3219 ret = lttng_metadata_printf(session,
3220 "\"");
3221 if (ret)
3222 goto end;
3223 len = strlen(entry->string);
3224 /* Escape the character '"' */
3225 for (j = 0; j < len; j++) {
3226 char c = entry->string[j];
3227
3228 switch (c) {
3229 case '"':
3230 ret = lttng_metadata_printf(session,
3231 "\\\"");
3232 break;
3233 case '\\':
3234 ret = lttng_metadata_printf(session,
3235 "\\\\");
3236 break;
3237 default:
3238 ret = lttng_metadata_printf(session,
3239 "%c", c);
3240 break;
3241 }
3242 if (ret)
3243 goto end;
3244 }
3245 ret = lttng_metadata_printf(session, "\"");
3246 if (ret)
3247 goto end;
3248
3249 if (entry->options.is_auto) {
3250 ret = lttng_metadata_printf(session, ",\n");
3251 if (ret)
3252 goto end;
3253 } else {
3254 ret = lttng_metadata_printf(session,
3255 " = ");
3256 if (ret)
3257 goto end;
3258 if (entry->start.signedness)
3259 ret = lttng_metadata_printf(session,
3260 "%lld", (long long) entry->start.value);
3261 else
3262 ret = lttng_metadata_printf(session,
3263 "%llu", entry->start.value);
3264 if (ret)
3265 goto end;
3266 if (entry->start.signedness == entry->end.signedness &&
3267 entry->start.value
3268 == entry->end.value) {
3269 ret = lttng_metadata_printf(session,
3270 ",\n");
3271 } else {
3272 if (entry->end.signedness) {
3273 ret = lttng_metadata_printf(session,
3274 " ... %lld,\n",
3275 (long long) entry->end.value);
3276 } else {
3277 ret = lttng_metadata_printf(session,
3278 " ... %llu,\n",
3279 entry->end.value);
3280 }
3281 }
3282 if (ret)
3283 goto end;
3284 }
3285 }
3286 ret = print_tabs(session, nesting);
3287 if (ret)
3288 goto end;
3289 ret = lttng_metadata_printf(session, "}");
3290 end:
3291 return ret;
3292 }
3293
3294 /*
3295 * Must be called with sessions_mutex held.
3296 */
3297 static
3298 int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3299 const struct lttng_kernel_event_field *field,
3300 size_t nesting)
3301 {
3302 int ret;
3303 const struct lttng_kernel_type_enum *enum_type;
3304
3305 enum_type = lttng_kernel_get_type_enum(field->type);
3306 WARN_ON_ONCE(!enum_type);
3307 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3308 if (ret)
3309 return ret;
3310 return lttng_field_name_statedump(session, field, nesting);
3311 }
3312
3313 static
3314 int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3315 const struct lttng_kernel_event_field *field,
3316 size_t nesting)
3317 {
3318 int ret;
3319
3320 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3321 lttng_kernel_string_encoding_none, nesting);
3322 if (ret)
3323 return ret;
3324 return lttng_field_name_statedump(session, field, nesting);
3325 }
3326
3327 static
3328 int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3329 const struct lttng_kernel_type_string *type,
3330 size_t nesting)
3331 {
3332 int ret;
3333
3334 /* Default encoding is UTF8 */
3335 ret = print_tabs(session, nesting);
3336 if (ret)
3337 return ret;
3338 ret = lttng_metadata_printf(session,
3339 "string%s",
3340 type->encoding == lttng_kernel_string_encoding_ASCII ?
3341 " { encoding = ASCII; }" : "");
3342 return ret;
3343 }
3344
3345 static
3346 int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3347 const struct lttng_kernel_event_field *field,
3348 size_t nesting)
3349 {
3350 const struct lttng_kernel_type_string *string_type;
3351 int ret;
3352
3353 string_type = lttng_kernel_get_type_string(field->type);
3354 WARN_ON_ONCE(!string_type);
3355 ret = _lttng_string_type_statedump(session, string_type, nesting);
3356 if (ret)
3357 return ret;
3358 return lttng_field_name_statedump(session, field, nesting);
3359 }
3360
3361 /*
3362 * Must be called with sessions_mutex held.
3363 */
3364 static
3365 int _lttng_type_statedump(struct lttng_kernel_session *session,
3366 const struct lttng_kernel_type_common *type,
3367 enum lttng_kernel_string_encoding parent_encoding,
3368 size_t nesting)
3369 {
3370 int ret = 0;
3371
3372 switch (type->type) {
3373 case lttng_kernel_type_integer:
3374 ret = _lttng_integer_type_statedump(session,
3375 lttng_kernel_get_type_integer(type),
3376 parent_encoding, nesting);
3377 break;
3378 case lttng_kernel_type_enum:
3379 ret = _lttng_enum_type_statedump(session,
3380 lttng_kernel_get_type_enum(type),
3381 nesting);
3382 break;
3383 case lttng_kernel_type_string:
3384 ret = _lttng_string_type_statedump(session,
3385 lttng_kernel_get_type_string(type),
3386 nesting);
3387 break;
3388 case lttng_kernel_type_struct:
3389 ret = _lttng_struct_type_statedump(session,
3390 lttng_kernel_get_type_struct(type),
3391 nesting);
3392 break;
3393 case lttng_kernel_type_variant:
3394 ret = _lttng_variant_type_statedump(session,
3395 lttng_kernel_get_type_variant(type),
3396 nesting, NULL);
3397 break;
3398
3399 /* Nested arrays and sequences are not supported yet. */
3400 case lttng_kernel_type_array:
3401 case lttng_kernel_type_sequence:
3402 default:
3403 WARN_ON_ONCE(1);
3404 return -EINVAL;
3405 }
3406 return ret;
3407 }
3408
3409 /*
3410 * Must be called with sessions_mutex held.
3411 */
3412 static
3413 int _lttng_field_statedump(struct lttng_kernel_session *session,
3414 const struct lttng_kernel_event_field *field,
3415 size_t nesting,
3416 const char **prev_field_name_p)
3417 {
3418 const char *prev_field_name = NULL;
3419 int ret = 0;
3420
3421 if (prev_field_name_p)
3422 prev_field_name = *prev_field_name_p;
3423 switch (field->type->type) {
3424 case lttng_kernel_type_integer:
3425 ret = _lttng_integer_field_statedump(session, field, nesting);
3426 break;
3427 case lttng_kernel_type_enum:
3428 ret = _lttng_enum_field_statedump(session, field, nesting);
3429 break;
3430 case lttng_kernel_type_string:
3431 ret = _lttng_string_field_statedump(session, field, nesting);
3432 break;
3433 case lttng_kernel_type_struct:
3434 ret = _lttng_struct_field_statedump(session, field, nesting);
3435 break;
3436 case lttng_kernel_type_array:
3437 ret = _lttng_array_field_statedump(session, field, nesting);
3438 break;
3439 case lttng_kernel_type_sequence:
3440 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3441 break;
3442 case lttng_kernel_type_variant:
3443 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3444 break;
3445
3446 default:
3447 WARN_ON_ONCE(1);
3448 return -EINVAL;
3449 }
3450 if (prev_field_name_p)
3451 *prev_field_name_p = field->name;
3452 return ret;
3453 }
3454
3455 static
3456 int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3457 struct lttng_kernel_ctx *ctx)
3458 {
3459 const char *prev_field_name = NULL;
3460 int ret = 0;
3461 int i;
3462
3463 if (!ctx)
3464 return 0;
3465 for (i = 0; i < ctx->nr_fields; i++) {
3466 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3467
3468 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3469 if (ret)
3470 return ret;
3471 }
3472 return ret;
3473 }
3474
3475 static
3476 int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3477 struct lttng_kernel_event_recorder *event_recorder)
3478 {
3479 const char *prev_field_name = NULL;
3480 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3481 int ret = 0;
3482 int i;
3483
3484 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3485 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3486
3487 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3488 if (ret)
3489 return ret;
3490 }
3491 return ret;
3492 }
3493
3494 /*
3495 * Must be called with sessions_mutex held.
3496 * The entire event metadata is printed as a single atomic metadata
3497 * transaction.
3498 */
3499 static
3500 int _lttng_event_recorder_metadata_statedump(struct lttng_kernel_event_common *event)
3501 {
3502 struct lttng_kernel_event_recorder *event_recorder;
3503 struct lttng_kernel_channel_buffer *chan;
3504 struct lttng_kernel_session *session;
3505 int ret = 0;
3506
3507 if (event->type != LTTNG_KERNEL_EVENT_TYPE_RECORDER)
3508 return 0;
3509 event_recorder = container_of(event, struct lttng_kernel_event_recorder, parent);
3510 chan = event_recorder->chan;
3511 session = chan->parent.session;
3512
3513 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3514 return 0;
3515 if (chan->priv->channel_type == METADATA_CHANNEL)
3516 return 0;
3517
3518 lttng_metadata_begin(session);
3519
3520 ret = lttng_metadata_printf(session,
3521 "event {\n"
3522 " name = \"%s\";\n"
3523 " id = %u;\n"
3524 " stream_id = %u;\n",
3525 event_recorder->priv->parent.desc->event_name,
3526 event_recorder->priv->id,
3527 event_recorder->chan->priv->id);
3528 if (ret)
3529 goto end;
3530
3531 ret = lttng_metadata_printf(session,
3532 " fields := struct {\n"
3533 );
3534 if (ret)
3535 goto end;
3536
3537 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3538 if (ret)
3539 goto end;
3540
3541 /*
3542 * LTTng space reservation can only reserve multiples of the
3543 * byte size.
3544 */
3545 ret = lttng_metadata_printf(session,
3546 " };\n"
3547 "};\n\n");
3548 if (ret)
3549 goto end;
3550
3551 event_recorder->priv->metadata_dumped = 1;
3552 end:
3553 lttng_metadata_end(session);
3554 return ret;
3555
3556 }
3557
3558 /*
3559 * Must be called with sessions_mutex held.
3560 * The entire channel metadata is printed as a single atomic metadata
3561 * transaction.
3562 */
3563 static
3564 int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3565 struct lttng_kernel_channel_buffer *chan)
3566 {
3567 int ret = 0;
3568
3569 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3570 return 0;
3571
3572 if (chan->priv->channel_type == METADATA_CHANNEL)
3573 return 0;
3574
3575 lttng_metadata_begin(session);
3576
3577 WARN_ON_ONCE(!chan->priv->header_type);
3578 ret = lttng_metadata_printf(session,
3579 "stream {\n"
3580 " id = %u;\n"
3581 " event.header := %s;\n"
3582 " packet.context := struct packet_context;\n",
3583 chan->priv->id,
3584 chan->priv->header_type == 1 ? "struct event_header_compact" :
3585 "struct event_header_large");
3586 if (ret)
3587 goto end;
3588
3589 if (chan->priv->ctx) {
3590 ret = lttng_metadata_printf(session,
3591 " event.context := struct {\n");
3592 if (ret)
3593 goto end;
3594 }
3595 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3596 if (ret)
3597 goto end;
3598 if (chan->priv->ctx) {
3599 ret = lttng_metadata_printf(session,
3600 " };\n");
3601 if (ret)
3602 goto end;
3603 }
3604
3605 ret = lttng_metadata_printf(session,
3606 "};\n\n");
3607
3608 chan->priv->metadata_dumped = 1;
3609 end:
3610 lttng_metadata_end(session);
3611 return ret;
3612 }
3613
3614 /*
3615 * Must be called with sessions_mutex held.
3616 */
3617 static
3618 int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3619 {
3620 return lttng_metadata_printf(session,
3621 "struct packet_context {\n"
3622 " uint64_clock_monotonic_t timestamp_begin;\n"
3623 " uint64_clock_monotonic_t timestamp_end;\n"
3624 " uint64_t content_size;\n"
3625 " uint64_t packet_size;\n"
3626 " uint64_t packet_seq_num;\n"
3627 " unsigned long events_discarded;\n"
3628 " uint32_t cpu_id;\n"
3629 "};\n\n"
3630 );
3631 }
3632
3633 /*
3634 * Compact header:
3635 * id: range: 0 - 30.
3636 * id 31 is reserved to indicate an extended header.
3637 *
3638 * Large header:
3639 * id: range: 0 - 65534.
3640 * id 65535 is reserved to indicate an extended header.
3641 *
3642 * Must be called with sessions_mutex held.
3643 */
3644 static
3645 int _lttng_event_header_declare(struct lttng_kernel_session *session)
3646 {
3647 return lttng_metadata_printf(session,
3648 "struct event_header_compact {\n"
3649 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3650 " variant <id> {\n"
3651 " struct {\n"
3652 " uint27_clock_monotonic_t timestamp;\n"
3653 " } compact;\n"
3654 " struct {\n"
3655 " uint32_t id;\n"
3656 " uint64_clock_monotonic_t timestamp;\n"
3657 " } extended;\n"
3658 " } v;\n"
3659 "} align(%u);\n"
3660 "\n"
3661 "struct event_header_large {\n"
3662 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3663 " variant <id> {\n"
3664 " struct {\n"
3665 " uint32_clock_monotonic_t timestamp;\n"
3666 " } compact;\n"
3667 " struct {\n"
3668 " uint32_t id;\n"
3669 " uint64_clock_monotonic_t timestamp;\n"
3670 " } extended;\n"
3671 " } v;\n"
3672 "} align(%u);\n\n",
3673 lttng_alignof(uint32_t) * CHAR_BIT,
3674 lttng_alignof(uint16_t) * CHAR_BIT
3675 );
3676 }
3677
3678 /*
3679 * Approximation of NTP time of day to clock monotonic correlation,
3680 * taken at start of trace.
3681 * Yes, this is only an approximation. Yes, we can (and will) do better
3682 * in future versions.
3683 * This function may return a negative offset. It may happen if the
3684 * system sets the REALTIME clock to 0 after boot.
3685 *
3686 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3687 * y2038 compliant.
3688 */
3689 static
3690 int64_t measure_clock_offset(void)
3691 {
3692 uint64_t monotonic_avg, monotonic[2], realtime;
3693 uint64_t tcf = trace_clock_freq();
3694 int64_t offset;
3695 unsigned long flags;
3696 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3697 struct timespec64 rts = { 0, 0 };
3698 #else
3699 struct timespec rts = { 0, 0 };
3700 #endif
3701
3702 /* Disable interrupts to increase correlation precision. */
3703 local_irq_save(flags);
3704 monotonic[0] = trace_clock_read64();
3705 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3706 ktime_get_real_ts64(&rts);
3707 #else
3708 getnstimeofday(&rts);
3709 #endif
3710 monotonic[1] = trace_clock_read64();
3711 local_irq_restore(flags);
3712
3713 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3714 realtime = (uint64_t) rts.tv_sec * tcf;
3715 if (tcf == NSEC_PER_SEC) {
3716 realtime += rts.tv_nsec;
3717 } else {
3718 uint64_t n = rts.tv_nsec * tcf;
3719
3720 do_div(n, NSEC_PER_SEC);
3721 realtime += n;
3722 }
3723 offset = (int64_t) realtime - monotonic_avg;
3724 return offset;
3725 }
3726
3727 static
3728 int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3729 {
3730 int ret = 0;
3731 size_t i;
3732 char cur;
3733
3734 i = 0;
3735 cur = string[i];
3736 while (cur != '\0') {
3737 switch (cur) {
3738 case '\n':
3739 ret = lttng_metadata_printf(session, "%s", "\\n");
3740 break;
3741 case '\\':
3742 case '"':
3743 ret = lttng_metadata_printf(session, "%c", '\\');
3744 if (ret)
3745 goto error;
3746 /* We still print the current char */
3747 lttng_fallthrough;
3748 default:
3749 ret = lttng_metadata_printf(session, "%c", cur);
3750 break;
3751 }
3752
3753 if (ret)
3754 goto error;
3755
3756 cur = string[++i];
3757 }
3758 error:
3759 return ret;
3760 }
3761
3762 static
3763 int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3764 const char *field_value)
3765 {
3766 int ret;
3767
3768 ret = lttng_metadata_printf(session, " %s = \"", field);
3769 if (ret)
3770 goto error;
3771
3772 ret = print_escaped_ctf_string(session, field_value);
3773 if (ret)
3774 goto error;
3775
3776 ret = lttng_metadata_printf(session, "\";\n");
3777
3778 error:
3779 return ret;
3780 }
3781
3782 /*
3783 * Output metadata into this session's metadata buffers.
3784 * Must be called with sessions_mutex held.
3785 */
3786 static
3787 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3788 {
3789 unsigned char *uuid_c = session->priv->uuid.b;
3790 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3791 const char *product_uuid;
3792 struct lttng_kernel_channel_buffer_private *chan_priv;
3793 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3794 int ret = 0;
3795
3796 if (!LTTNG_READ_ONCE(session->active))
3797 return 0;
3798
3799 lttng_metadata_begin(session);
3800
3801 if (session->priv->metadata_dumped)
3802 goto skip_session;
3803
3804 snprintf(uuid_s, sizeof(uuid_s),
3805 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3806 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3807 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3808 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3809 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3810
3811 ret = lttng_metadata_printf(session,
3812 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3813 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3814 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3815 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3816 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3817 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3818 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3819 "\n"
3820 "trace {\n"
3821 " major = %u;\n"
3822 " minor = %u;\n"
3823 " uuid = \"%s\";\n"
3824 " byte_order = %s;\n"
3825 " packet.header := struct {\n"
3826 " uint32_t magic;\n"
3827 " uint8_t uuid[16];\n"
3828 " uint32_t stream_id;\n"
3829 " uint64_t stream_instance_id;\n"
3830 " };\n"
3831 "};\n\n",
3832 lttng_alignof(uint8_t) * CHAR_BIT,
3833 lttng_alignof(uint16_t) * CHAR_BIT,
3834 lttng_alignof(uint32_t) * CHAR_BIT,
3835 lttng_alignof(uint64_t) * CHAR_BIT,
3836 sizeof(unsigned long) * CHAR_BIT,
3837 lttng_alignof(unsigned long) * CHAR_BIT,
3838 CTF_SPEC_MAJOR,
3839 CTF_SPEC_MINOR,
3840 uuid_s,
3841 #if __BYTE_ORDER == __BIG_ENDIAN
3842 "be"
3843 #else
3844 "le"
3845 #endif
3846 );
3847 if (ret)
3848 goto end;
3849
3850 ret = lttng_metadata_printf(session,
3851 "env {\n"
3852 " hostname = \"%s\";\n"
3853 " domain = \"kernel\";\n"
3854 " sysname = \"%s\";\n"
3855 " kernel_release = \"%s\";\n"
3856 " kernel_version = \"%s\";\n"
3857 " tracer_name = \"lttng-modules\";\n"
3858 " tracer_major = %d;\n"
3859 " tracer_minor = %d;\n"
3860 " tracer_patchlevel = %d;\n"
3861 " trace_buffering_scheme = \"global\";\n",
3862 current->nsproxy->uts_ns->name.nodename,
3863 utsname()->sysname,
3864 utsname()->release,
3865 utsname()->version,
3866 LTTNG_MODULES_MAJOR_VERSION,
3867 LTTNG_MODULES_MINOR_VERSION,
3868 LTTNG_MODULES_PATCHLEVEL_VERSION
3869 );
3870 if (ret)
3871 goto end;
3872
3873 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
3874 if (ret)
3875 goto end;
3876 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3877 session->priv->creation_time);
3878 if (ret)
3879 goto end;
3880
3881 /* Add the product UUID to the 'env' section */
3882 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3883 if (product_uuid) {
3884 ret = lttng_metadata_printf(session,
3885 " product_uuid = \"%s\";\n",
3886 product_uuid
3887 );
3888 if (ret)
3889 goto end;
3890 }
3891
3892 /* Close the 'env' section */
3893 ret = lttng_metadata_printf(session, "};\n\n");
3894 if (ret)
3895 goto end;
3896
3897 ret = lttng_metadata_printf(session,
3898 "clock {\n"
3899 " name = \"%s\";\n",
3900 trace_clock_name()
3901 );
3902 if (ret)
3903 goto end;
3904
3905 if (!trace_clock_uuid(clock_uuid_s)) {
3906 ret = lttng_metadata_printf(session,
3907 " uuid = \"%s\";\n",
3908 clock_uuid_s
3909 );
3910 if (ret)
3911 goto end;
3912 }
3913
3914 ret = lttng_metadata_printf(session,
3915 " description = \"%s\";\n"
3916 " freq = %llu; /* Frequency, in Hz */\n"
3917 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
3918 " offset = %lld;\n"
3919 "};\n\n",
3920 trace_clock_description(),
3921 (unsigned long long) trace_clock_freq(),
3922 (long long) measure_clock_offset()
3923 );
3924 if (ret)
3925 goto end;
3926
3927 ret = lttng_metadata_printf(session,
3928 "typealias integer {\n"
3929 " size = 27; align = 1; signed = false;\n"
3930 " map = clock.%s.value;\n"
3931 "} := uint27_clock_monotonic_t;\n"
3932 "\n"
3933 "typealias integer {\n"
3934 " size = 32; align = %u; signed = false;\n"
3935 " map = clock.%s.value;\n"
3936 "} := uint32_clock_monotonic_t;\n"
3937 "\n"
3938 "typealias integer {\n"
3939 " size = 64; align = %u; signed = false;\n"
3940 " map = clock.%s.value;\n"
3941 "} := uint64_clock_monotonic_t;\n\n",
3942 trace_clock_name(),
3943 lttng_alignof(uint32_t) * CHAR_BIT,
3944 trace_clock_name(),
3945 lttng_alignof(uint64_t) * CHAR_BIT,
3946 trace_clock_name()
3947 );
3948 if (ret)
3949 goto end;
3950
3951 ret = _lttng_stream_packet_context_declare(session);
3952 if (ret)
3953 goto end;
3954
3955 ret = _lttng_event_header_declare(session);
3956 if (ret)
3957 goto end;
3958
3959 skip_session:
3960 list_for_each_entry(chan_priv, &session->priv->chan, node) {
3961 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
3962 if (ret)
3963 goto end;
3964 }
3965
3966 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
3967 ret = _lttng_event_recorder_metadata_statedump(&event_recorder_priv->pub->parent);
3968 if (ret)
3969 goto end;
3970 }
3971 session->priv->metadata_dumped = 1;
3972 end:
3973 lttng_metadata_end(session);
3974 return ret;
3975 }
3976
3977 /**
3978 * lttng_transport_register - LTT transport registration
3979 * @transport: transport structure
3980 *
3981 * Registers a transport which can be used as output to extract the data out of
3982 * LTTng. The module calling this registration function must ensure that no
3983 * trap-inducing code will be executed by the transport functions. E.g.
3984 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
3985 * is made visible to the transport function. This registration acts as a
3986 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
3987 * after its registration must it synchronize the TLBs.
3988 */
3989 void lttng_transport_register(struct lttng_transport *transport)
3990 {
3991 /*
3992 * Make sure no page fault can be triggered by the module about to be
3993 * registered. We deal with this here so we don't have to call
3994 * vmalloc_sync_mappings() in each module's init.
3995 */
3996 wrapper_vmalloc_sync_mappings();
3997
3998 mutex_lock(&sessions_mutex);
3999 list_add_tail(&transport->node, &lttng_transport_list);
4000 mutex_unlock(&sessions_mutex);
4001 }
4002 EXPORT_SYMBOL_GPL(lttng_transport_register);
4003
4004 /**
4005 * lttng_transport_unregister - LTT transport unregistration
4006 * @transport: transport structure
4007 */
4008 void lttng_transport_unregister(struct lttng_transport *transport)
4009 {
4010 mutex_lock(&sessions_mutex);
4011 list_del(&transport->node);
4012 mutex_unlock(&sessions_mutex);
4013 }
4014 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4015
4016 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4017 {
4018 /*
4019 * Make sure no page fault can be triggered by the module about to be
4020 * registered. We deal with this here so we don't have to call
4021 * vmalloc_sync_mappings() in each module's init.
4022 */
4023 wrapper_vmalloc_sync_mappings();
4024
4025 mutex_lock(&sessions_mutex);
4026 list_add_tail(&transport->node, &lttng_counter_transport_list);
4027 mutex_unlock(&sessions_mutex);
4028 }
4029 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4030
4031 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4032 {
4033 mutex_lock(&sessions_mutex);
4034 list_del(&transport->node);
4035 mutex_unlock(&sessions_mutex);
4036 }
4037 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4038
4039 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4040
4041 enum cpuhp_state lttng_hp_prepare;
4042 enum cpuhp_state lttng_hp_online;
4043
4044 static int lttng_hotplug_prepare(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 0;
4052 case LTTNG_RING_BUFFER_BACKEND:
4053 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4054 case LTTNG_RING_BUFFER_ITER:
4055 return 0;
4056 case LTTNG_CONTEXT_PERF_COUNTERS:
4057 return 0;
4058 default:
4059 return -EINVAL;
4060 }
4061 }
4062
4063 static int lttng_hotplug_dead(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_dead(cpu, lttng_node);
4071 case LTTNG_RING_BUFFER_BACKEND:
4072 return 0;
4073 case LTTNG_RING_BUFFER_ITER:
4074 return 0;
4075 case LTTNG_CONTEXT_PERF_COUNTERS:
4076 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4077 default:
4078 return -EINVAL;
4079 }
4080 }
4081
4082 static int lttng_hotplug_online(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_online(cpu, lttng_node);
4090 case LTTNG_RING_BUFFER_BACKEND:
4091 return 0;
4092 case LTTNG_RING_BUFFER_ITER:
4093 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4094 case LTTNG_CONTEXT_PERF_COUNTERS:
4095 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4096 default:
4097 return -EINVAL;
4098 }
4099 }
4100
4101 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4102 {
4103 struct lttng_cpuhp_node *lttng_node;
4104
4105 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4106 switch (lttng_node->component) {
4107 case LTTNG_RING_BUFFER_FRONTEND:
4108 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4109 case LTTNG_RING_BUFFER_BACKEND:
4110 return 0;
4111 case LTTNG_RING_BUFFER_ITER:
4112 return 0;
4113 case LTTNG_CONTEXT_PERF_COUNTERS:
4114 return 0;
4115 default:
4116 return -EINVAL;
4117 }
4118 }
4119
4120 static int __init lttng_init_cpu_hotplug(void)
4121 {
4122 int ret;
4123
4124 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4125 lttng_hotplug_prepare,
4126 lttng_hotplug_dead);
4127 if (ret < 0) {
4128 return ret;
4129 }
4130 lttng_hp_prepare = ret;
4131 lttng_rb_set_hp_prepare(ret);
4132
4133 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4134 lttng_hotplug_online,
4135 lttng_hotplug_offline);
4136 if (ret < 0) {
4137 cpuhp_remove_multi_state(lttng_hp_prepare);
4138 lttng_hp_prepare = 0;
4139 return ret;
4140 }
4141 lttng_hp_online = ret;
4142 lttng_rb_set_hp_online(ret);
4143
4144 return 0;
4145 }
4146
4147 static void __exit lttng_exit_cpu_hotplug(void)
4148 {
4149 lttng_rb_set_hp_online(0);
4150 cpuhp_remove_multi_state(lttng_hp_online);
4151 lttng_rb_set_hp_prepare(0);
4152 cpuhp_remove_multi_state(lttng_hp_prepare);
4153 }
4154
4155 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4156 static int lttng_init_cpu_hotplug(void)
4157 {
4158 return 0;
4159 }
4160 static void lttng_exit_cpu_hotplug(void)
4161 {
4162 }
4163 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4164
4165 static int __init lttng_events_init(void)
4166 {
4167 int ret;
4168
4169 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4170 if (ret)
4171 return ret;
4172 ret = wrapper_get_pfnblock_flags_mask_init();
4173 if (ret)
4174 return ret;
4175 ret = wrapper_get_pageblock_flags_mask_init();
4176 if (ret)
4177 return ret;
4178 ret = lttng_probes_init();
4179 if (ret)
4180 return ret;
4181 ret = lttng_context_init();
4182 if (ret)
4183 return ret;
4184 ret = lttng_tracepoint_init();
4185 if (ret)
4186 goto error_tp;
4187 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4188 if (!event_recorder_cache) {
4189 ret = -ENOMEM;
4190 goto error_kmem_event_recorder;
4191 }
4192 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4193 if (!event_recorder_private_cache) {
4194 ret = -ENOMEM;
4195 goto error_kmem_event_recorder_private;
4196 }
4197 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4198 if (!event_notifier_cache) {
4199 ret = -ENOMEM;
4200 goto error_kmem_event_notifier;
4201 }
4202 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4203 if (!event_notifier_private_cache) {
4204 ret = -ENOMEM;
4205 goto error_kmem_event_notifier_private;
4206 }
4207 ret = lttng_abi_init();
4208 if (ret)
4209 goto error_abi;
4210 ret = lttng_logger_init();
4211 if (ret)
4212 goto error_logger;
4213 ret = lttng_init_cpu_hotplug();
4214 if (ret)
4215 goto error_hotplug;
4216 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4217 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4218 __stringify(LTTNG_MODULES_MINOR_VERSION),
4219 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4220 LTTNG_MODULES_EXTRAVERSION,
4221 LTTNG_VERSION_NAME,
4222 #ifdef LTTNG_EXTRA_VERSION_GIT
4223 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4224 #else
4225 "",
4226 #endif
4227 #ifdef LTTNG_EXTRA_VERSION_NAME
4228 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4229 #else
4230 "");
4231 #endif
4232 #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
4233 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
4234 #endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
4235 return 0;
4236
4237 error_hotplug:
4238 lttng_logger_exit();
4239 error_logger:
4240 lttng_abi_exit();
4241 error_abi:
4242 kmem_cache_destroy(event_notifier_private_cache);
4243 error_kmem_event_notifier_private:
4244 kmem_cache_destroy(event_notifier_cache);
4245 error_kmem_event_notifier:
4246 kmem_cache_destroy(event_recorder_private_cache);
4247 error_kmem_event_recorder_private:
4248 kmem_cache_destroy(event_recorder_cache);
4249 error_kmem_event_recorder:
4250 lttng_tracepoint_exit();
4251 error_tp:
4252 lttng_context_exit();
4253 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4254 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4255 __stringify(LTTNG_MODULES_MINOR_VERSION),
4256 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4257 LTTNG_MODULES_EXTRAVERSION,
4258 LTTNG_VERSION_NAME,
4259 #ifdef LTTNG_EXTRA_VERSION_GIT
4260 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4261 #else
4262 "",
4263 #endif
4264 #ifdef LTTNG_EXTRA_VERSION_NAME
4265 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4266 #else
4267 "");
4268 #endif
4269 return ret;
4270 }
4271
4272 module_init(lttng_events_init);
4273
4274 static void __exit lttng_events_exit(void)
4275 {
4276 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4277
4278 lttng_exit_cpu_hotplug();
4279 lttng_logger_exit();
4280 lttng_abi_exit();
4281 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4282 lttng_session_destroy(session_priv->pub);
4283 kmem_cache_destroy(event_recorder_cache);
4284 kmem_cache_destroy(event_recorder_private_cache);
4285 kmem_cache_destroy(event_notifier_cache);
4286 kmem_cache_destroy(event_notifier_private_cache);
4287 lttng_tracepoint_exit();
4288 lttng_context_exit();
4289 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4290 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4291 __stringify(LTTNG_MODULES_MINOR_VERSION),
4292 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4293 LTTNG_MODULES_EXTRAVERSION,
4294 LTTNG_VERSION_NAME,
4295 #ifdef LTTNG_EXTRA_VERSION_GIT
4296 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4297 #else
4298 "",
4299 #endif
4300 #ifdef LTTNG_EXTRA_VERSION_NAME
4301 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4302 #else
4303 "");
4304 #endif
4305 }
4306
4307 module_exit(lttng_events_exit);
4308
4309 #include <generated/patches.h>
4310 #ifdef LTTNG_EXTRA_VERSION_GIT
4311 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4312 #endif
4313 #ifdef LTTNG_EXTRA_VERSION_NAME
4314 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4315 #endif
4316 MODULE_LICENSE("GPL and additional rights");
4317 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4318 MODULE_DESCRIPTION("LTTng tracer");
4319 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4320 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4321 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4322 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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