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Drop support for kernels < 4.4 from LTTng tracer core
[lttng-modules.git] / src / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
2 *
3 * lttng-events.c
4 *
5 * Holds LTTng per-session event registry.
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10 /*
11 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
12 * overrides a function with a define.
13 */
14 #include "wrapper/page_alloc.h"
15
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/jiffies.h>
21 #include <linux/utsname.h>
22 #include <linux/err.h>
23 #include <linux/seq_file.h>
24 #include <linux/file.h>
25 #include <linux/anon_inodes.h>
26 #include <linux/uaccess.h>
27 #include <linux/vmalloc.h>
28 #include <linux/dmi.h>
29
30 #include <wrapper/compiler_attributes.h>
31 #include <wrapper/uuid.h>
32 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
33 #include <wrapper/random.h>
34 #include <wrapper/tracepoint.h>
35 #include <wrapper/list.h>
36 #include <wrapper/types.h>
37 #include <lttng/kernel-version.h>
38 #include <lttng/events.h>
39 #include <lttng/events-internal.h>
40 #include <lttng/lttng-bytecode.h>
41 #include <lttng/tracer.h>
42 #include <lttng/event-notifier-notification.h>
43 #include <lttng/abi-old.h>
44 #include <lttng/endian.h>
45 #include <lttng/string-utils.h>
46 #include <lttng/utils.h>
47 #include <ringbuffer/backend.h>
48 #include <ringbuffer/frontend.h>
49
50 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,16,0))
51 #include <linux/stdarg.h>
52 #else
53 #include <stdarg.h>
54 #endif
55
56 #define METADATA_CACHE_DEFAULT_SIZE 4096
57
58 static LIST_HEAD(sessions);
59 static LIST_HEAD(event_notifier_groups);
60 static LIST_HEAD(lttng_transport_list);
61 static LIST_HEAD(lttng_counter_transport_list);
62 /*
63 * Protect the sessions and metadata caches.
64 */
65 static DEFINE_MUTEX(sessions_mutex);
66 static struct kmem_cache *event_recorder_cache;
67 static struct kmem_cache *event_recorder_private_cache;
68 static struct kmem_cache *event_notifier_cache;
69 static struct kmem_cache *event_notifier_private_cache;
70
71 static void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session);
72 static void lttng_session_sync_event_enablers(struct lttng_kernel_session *session);
73 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
74 static void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler);
75
76 static void _lttng_event_destroy(struct lttng_kernel_event_common *event);
77 static void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan);
78 static void _lttng_event_unregister(struct lttng_kernel_event_common *event);
79 static
80 int _lttng_event_recorder_metadata_statedump(struct lttng_kernel_event_common *event);
81 static
82 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session);
83 static
84 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
85 static
86 int _lttng_type_statedump(struct lttng_kernel_session *session,
87 const struct lttng_kernel_type_common *type,
88 enum lttng_kernel_string_encoding parent_encoding,
89 size_t nesting);
90 static
91 int _lttng_field_statedump(struct lttng_kernel_session *session,
92 const struct lttng_kernel_event_field *field,
93 size_t nesting, const char **prev_field_name_p);
94
95 void synchronize_trace(void)
96 {
97 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0) || \
98 LTTNG_RHEL_KERNEL_RANGE(4,18,0,193,0,0, 4,19,0,0,0,0))
99 synchronize_rcu();
100 #else
101 synchronize_sched();
102 #endif
103
104 #ifdef CONFIG_PREEMPT_RT_FULL
105 synchronize_rcu();
106 #endif
107 }
108
109 void lttng_lock_sessions(void)
110 {
111 mutex_lock(&sessions_mutex);
112 }
113
114 void lttng_unlock_sessions(void)
115 {
116 mutex_unlock(&sessions_mutex);
117 }
118
119 static struct lttng_transport *lttng_transport_find(const char *name)
120 {
121 struct lttng_transport *transport;
122
123 list_for_each_entry(transport, &lttng_transport_list, node) {
124 if (!strcmp(transport->name, name))
125 return transport;
126 }
127 return NULL;
128 }
129
130 /*
131 * Called with sessions lock held.
132 */
133 int lttng_session_active(void)
134 {
135 struct lttng_kernel_session_private *iter;
136
137 list_for_each_entry(iter, &sessions, list) {
138 if (iter->pub->active)
139 return 1;
140 }
141 return 0;
142 }
143
144 struct lttng_kernel_session *lttng_session_create(void)
145 {
146 struct lttng_kernel_session *session;
147 struct lttng_kernel_session_private *session_priv;
148 struct lttng_metadata_cache *metadata_cache;
149 int i;
150
151 mutex_lock(&sessions_mutex);
152 session = lttng_kvzalloc(sizeof(*session), GFP_KERNEL);
153 if (!session)
154 goto err;
155 session_priv = lttng_kvzalloc(sizeof(*session_priv), GFP_KERNEL);
156 if (!session_priv)
157 goto err_free_session;
158 session->priv = session_priv;
159 session_priv->pub = session;
160
161 INIT_LIST_HEAD(&session_priv->chan);
162 INIT_LIST_HEAD(&session_priv->events);
163 lttng_guid_gen(&session_priv->uuid);
164
165 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
166 GFP_KERNEL);
167 if (!metadata_cache)
168 goto err_free_session_private;
169 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
170 if (!metadata_cache->data)
171 goto err_free_cache;
172 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
173 kref_init(&metadata_cache->refcount);
174 mutex_init(&metadata_cache->lock);
175 session_priv->metadata_cache = metadata_cache;
176 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
177 memcpy(&metadata_cache->uuid, &session_priv->uuid,
178 sizeof(metadata_cache->uuid));
179 INIT_LIST_HEAD(&session_priv->enablers_head);
180 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
181 INIT_HLIST_HEAD(&session_priv->events_ht.table[i]);
182 list_add(&session_priv->list, &sessions);
183
184 if (lttng_id_tracker_init(&session->pid_tracker, session, TRACKER_PID))
185 goto tracker_alloc_error;
186 if (lttng_id_tracker_init(&session->vpid_tracker, session, TRACKER_VPID))
187 goto tracker_alloc_error;
188 if (lttng_id_tracker_init(&session->uid_tracker, session, TRACKER_UID))
189 goto tracker_alloc_error;
190 if (lttng_id_tracker_init(&session->vuid_tracker, session, TRACKER_VUID))
191 goto tracker_alloc_error;
192 if (lttng_id_tracker_init(&session->gid_tracker, session, TRACKER_GID))
193 goto tracker_alloc_error;
194 if (lttng_id_tracker_init(&session->vgid_tracker, session, TRACKER_VGID))
195 goto tracker_alloc_error;
196
197 mutex_unlock(&sessions_mutex);
198
199 return session;
200
201 tracker_alloc_error:
202 lttng_id_tracker_fini(&session->pid_tracker);
203 lttng_id_tracker_fini(&session->vpid_tracker);
204 lttng_id_tracker_fini(&session->uid_tracker);
205 lttng_id_tracker_fini(&session->vuid_tracker);
206 lttng_id_tracker_fini(&session->gid_tracker);
207 lttng_id_tracker_fini(&session->vgid_tracker);
208 err_free_cache:
209 kfree(metadata_cache);
210 err_free_session_private:
211 lttng_kvfree(session_priv);
212 err_free_session:
213 lttng_kvfree(session);
214 err:
215 mutex_unlock(&sessions_mutex);
216 return NULL;
217 }
218
219 static
220 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
221 {
222 struct lttng_counter_transport *transport;
223
224 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
225 if (!strcmp(transport->name, name))
226 return transport;
227 }
228 return NULL;
229 }
230
231 struct lttng_counter *lttng_kernel_counter_create(
232 const char *counter_transport_name,
233 size_t number_dimensions, const size_t *dimensions_sizes)
234 {
235 struct lttng_counter *counter = NULL;
236 struct lttng_counter_transport *counter_transport = NULL;
237
238 counter_transport = lttng_counter_transport_find(counter_transport_name);
239 if (!counter_transport) {
240 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
241 counter_transport_name);
242 goto notransport;
243 }
244 if (!try_module_get(counter_transport->owner)) {
245 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
246 goto notransport;
247 }
248
249 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
250 if (!counter)
251 goto nomem;
252
253 /* Create event notifier error counter. */
254 counter->ops = &counter_transport->ops;
255 counter->transport = counter_transport;
256
257 counter->counter = counter->ops->counter_create(
258 number_dimensions, dimensions_sizes, 0);
259 if (!counter->counter) {
260 goto create_error;
261 }
262
263 return counter;
264
265 create_error:
266 lttng_kvfree(counter);
267 nomem:
268 if (counter_transport)
269 module_put(counter_transport->owner);
270 notransport:
271 return NULL;
272 }
273
274 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
275 {
276 struct lttng_transport *transport = NULL;
277 struct lttng_event_notifier_group *event_notifier_group;
278 const char *transport_name = "relay-event-notifier";
279 size_t subbuf_size = 4096; //TODO
280 size_t num_subbuf = 16; //TODO
281 unsigned int switch_timer_interval = 0;
282 unsigned int read_timer_interval = 0;
283 int i;
284
285 mutex_lock(&sessions_mutex);
286
287 transport = lttng_transport_find(transport_name);
288 if (!transport) {
289 printk(KERN_WARNING "LTTng: transport %s not found\n",
290 transport_name);
291 goto notransport;
292 }
293 if (!try_module_get(transport->owner)) {
294 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
295 transport_name);
296 goto notransport;
297 }
298
299 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
300 GFP_KERNEL);
301 if (!event_notifier_group)
302 goto nomem;
303
304 /*
305 * Initialize the ring buffer used to store event notifier
306 * notifications.
307 */
308 event_notifier_group->ops = &transport->ops;
309 event_notifier_group->chan = transport->ops.priv->channel_create(
310 transport_name, event_notifier_group, NULL,
311 subbuf_size, num_subbuf, switch_timer_interval,
312 read_timer_interval);
313 if (!event_notifier_group->chan)
314 goto create_error;
315
316 event_notifier_group->transport = transport;
317
318 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
319 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
320 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
321 INIT_HLIST_HEAD(&event_notifier_group->events_ht.table[i]);
322
323 list_add(&event_notifier_group->node, &event_notifier_groups);
324
325 mutex_unlock(&sessions_mutex);
326
327 return event_notifier_group;
328
329 create_error:
330 lttng_kvfree(event_notifier_group);
331 nomem:
332 if (transport)
333 module_put(transport->owner);
334 notransport:
335 mutex_unlock(&sessions_mutex);
336 return NULL;
337 }
338
339 void metadata_cache_destroy(struct kref *kref)
340 {
341 struct lttng_metadata_cache *cache =
342 container_of(kref, struct lttng_metadata_cache, refcount);
343 vfree(cache->data);
344 kfree(cache);
345 }
346
347 void lttng_session_destroy(struct lttng_kernel_session *session)
348 {
349 struct lttng_kernel_channel_buffer_private *chan_priv, *tmpchan_priv;
350 struct lttng_kernel_event_recorder_private *event_recorder_priv, *tmpevent_recorder_priv;
351 struct lttng_metadata_stream *metadata_stream;
352 struct lttng_event_enabler_common *event_enabler, *tmp_event_enabler;
353 int ret;
354
355 mutex_lock(&sessions_mutex);
356 WRITE_ONCE(session->active, 0);
357 list_for_each_entry(chan_priv, &session->priv->chan, node) {
358 ret = lttng_syscalls_unregister_syscall_table(&chan_priv->parent.syscall_table);
359 WARN_ON(ret);
360 }
361 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node)
362 _lttng_event_unregister(&event_recorder_priv->pub->parent);
363 synchronize_trace(); /* Wait for in-flight events to complete */
364 list_for_each_entry(chan_priv, &session->priv->chan, node) {
365 ret = lttng_syscalls_destroy_syscall_table(&chan_priv->parent.syscall_table);
366 WARN_ON(ret);
367 }
368 list_for_each_entry_safe(event_enabler, tmp_event_enabler, &session->priv->enablers_head, node)
369 lttng_event_enabler_destroy(event_enabler);
370 list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv, &session->priv->events, parent.node)
371 _lttng_event_destroy(&event_recorder_priv->pub->parent);
372 list_for_each_entry_safe(chan_priv, tmpchan_priv, &session->priv->chan, node) {
373 BUG_ON(chan_priv->channel_type == METADATA_CHANNEL);
374 _lttng_channel_destroy(chan_priv->pub);
375 }
376 mutex_lock(&session->priv->metadata_cache->lock);
377 list_for_each_entry(metadata_stream, &session->priv->metadata_cache->metadata_stream, list)
378 _lttng_metadata_channel_hangup(metadata_stream);
379 mutex_unlock(&session->priv->metadata_cache->lock);
380 lttng_id_tracker_fini(&session->pid_tracker);
381 lttng_id_tracker_fini(&session->vpid_tracker);
382 lttng_id_tracker_fini(&session->uid_tracker);
383 lttng_id_tracker_fini(&session->vuid_tracker);
384 lttng_id_tracker_fini(&session->gid_tracker);
385 lttng_id_tracker_fini(&session->vgid_tracker);
386 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
387 list_del(&session->priv->list);
388 mutex_unlock(&sessions_mutex);
389 lttng_kvfree(session->priv);
390 lttng_kvfree(session);
391 }
392
393 void lttng_event_notifier_group_destroy(
394 struct lttng_event_notifier_group *event_notifier_group)
395 {
396 struct lttng_event_enabler_common *event_enabler, *tmp_event_enabler;
397 struct lttng_kernel_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
398 int ret;
399
400 if (!event_notifier_group)
401 return;
402
403 mutex_lock(&sessions_mutex);
404
405 ret = lttng_syscalls_unregister_syscall_table(&event_notifier_group->syscall_table);
406 WARN_ON(ret);
407
408 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
409 &event_notifier_group->event_notifiers_head, parent.node)
410 _lttng_event_unregister(&event_notifier_priv->pub->parent);
411
412 /* Wait for in-flight event notifier to complete */
413 synchronize_trace();
414
415 irq_work_sync(&event_notifier_group->wakeup_pending);
416
417 ret = lttng_syscalls_destroy_syscall_table(&event_notifier_group->syscall_table);
418 WARN_ON(ret);
419
420 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
421 &event_notifier_group->enablers_head, node)
422 lttng_event_enabler_destroy(event_enabler);
423
424 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
425 &event_notifier_group->event_notifiers_head, parent.node)
426 _lttng_event_destroy(&event_notifier_priv->pub->parent);
427
428 if (event_notifier_group->error_counter) {
429 struct lttng_counter *error_counter = event_notifier_group->error_counter;
430
431 error_counter->ops->counter_destroy(error_counter->counter);
432 module_put(error_counter->transport->owner);
433 lttng_kvfree(error_counter);
434 event_notifier_group->error_counter = NULL;
435 }
436
437 event_notifier_group->ops->priv->channel_destroy(event_notifier_group->chan);
438 module_put(event_notifier_group->transport->owner);
439 list_del(&event_notifier_group->node);
440
441 mutex_unlock(&sessions_mutex);
442 lttng_kvfree(event_notifier_group);
443 }
444
445 int lttng_session_statedump(struct lttng_kernel_session *session)
446 {
447 int ret;
448
449 mutex_lock(&sessions_mutex);
450 ret = lttng_statedump_start(session);
451 mutex_unlock(&sessions_mutex);
452 return ret;
453 }
454
455 int lttng_session_enable(struct lttng_kernel_session *session)
456 {
457 int ret = 0;
458 struct lttng_kernel_channel_buffer_private *chan_priv;
459
460 mutex_lock(&sessions_mutex);
461 if (session->active) {
462 ret = -EBUSY;
463 goto end;
464 }
465
466 /* Set transient enabler state to "enabled" */
467 session->priv->tstate = 1;
468
469 /* We need to sync enablers with session before activation. */
470 lttng_session_sync_event_enablers(session);
471
472 /*
473 * Snapshot the number of events per channel to know the type of header
474 * we need to use.
475 */
476 list_for_each_entry(chan_priv, &session->priv->chan, node) {
477 if (chan_priv->header_type)
478 continue; /* don't change it if session stop/restart */
479 if (chan_priv->free_event_id < 31)
480 chan_priv->header_type = 1; /* compact */
481 else
482 chan_priv->header_type = 2; /* large */
483 }
484
485 /* Clear each stream's quiescent state. */
486 list_for_each_entry(chan_priv, &session->priv->chan, node) {
487 if (chan_priv->channel_type != METADATA_CHANNEL)
488 lib_ring_buffer_clear_quiescent_channel(chan_priv->rb_chan);
489 }
490
491 WRITE_ONCE(session->active, 1);
492 WRITE_ONCE(session->priv->been_active, 1);
493 ret = _lttng_session_metadata_statedump(session);
494 if (ret) {
495 WRITE_ONCE(session->active, 0);
496 goto end;
497 }
498 ret = lttng_statedump_start(session);
499 if (ret)
500 WRITE_ONCE(session->active, 0);
501 end:
502 mutex_unlock(&sessions_mutex);
503 return ret;
504 }
505
506 int lttng_session_disable(struct lttng_kernel_session *session)
507 {
508 int ret = 0;
509 struct lttng_kernel_channel_buffer_private *chan_priv;
510
511 mutex_lock(&sessions_mutex);
512 if (!session->active) {
513 ret = -EBUSY;
514 goto end;
515 }
516 WRITE_ONCE(session->active, 0);
517
518 /* Set transient enabler state to "disabled" */
519 session->priv->tstate = 0;
520 lttng_session_sync_event_enablers(session);
521
522 /* Set each stream's quiescent state. */
523 list_for_each_entry(chan_priv, &session->priv->chan, node) {
524 if (chan_priv->channel_type != METADATA_CHANNEL)
525 lib_ring_buffer_set_quiescent_channel(chan_priv->rb_chan);
526 }
527 end:
528 mutex_unlock(&sessions_mutex);
529 return ret;
530 }
531
532 int lttng_session_metadata_regenerate(struct lttng_kernel_session *session)
533 {
534 int ret = 0;
535 struct lttng_kernel_channel_buffer_private *chan_priv;
536 struct lttng_kernel_event_recorder_private *event_recorder_priv;
537 struct lttng_metadata_cache *cache = session->priv->metadata_cache;
538 struct lttng_metadata_stream *stream;
539
540 mutex_lock(&sessions_mutex);
541 if (!session->active) {
542 ret = -EBUSY;
543 goto end;
544 }
545
546 mutex_lock(&cache->lock);
547 memset(cache->data, 0, cache->cache_alloc);
548 cache->metadata_written = 0;
549 cache->version++;
550 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list) {
551 stream->metadata_out = 0;
552 stream->metadata_in = 0;
553 }
554 mutex_unlock(&cache->lock);
555
556 session->priv->metadata_dumped = 0;
557 list_for_each_entry(chan_priv, &session->priv->chan, node) {
558 chan_priv->metadata_dumped = 0;
559 }
560
561 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
562 event_recorder_priv->metadata_dumped = 0;
563 }
564
565 ret = _lttng_session_metadata_statedump(session);
566
567 end:
568 mutex_unlock(&sessions_mutex);
569 return ret;
570 }
571
572 static
573 bool is_channel_buffer_metadata(struct lttng_kernel_channel_common *channel)
574 {
575 struct lttng_kernel_channel_buffer *chan_buf;
576
577 if (channel->type != LTTNG_KERNEL_CHANNEL_TYPE_BUFFER)
578 return false;
579 chan_buf = container_of(channel, struct lttng_kernel_channel_buffer, parent);
580 if (chan_buf->priv->channel_type == METADATA_CHANNEL)
581 return true;
582 return false;
583 }
584
585 int lttng_channel_enable(struct lttng_kernel_channel_common *channel)
586 {
587 int ret = 0;
588
589 mutex_lock(&sessions_mutex);
590 if (is_channel_buffer_metadata(channel)) {
591 ret = -EPERM;
592 goto end;
593 }
594 if (channel->enabled) {
595 ret = -EEXIST;
596 goto end;
597 }
598 /* Set transient enabler state to "enabled" */
599 channel->priv->tstate = 1;
600 lttng_session_sync_event_enablers(channel->session);
601 /* Set atomically the state to "enabled" */
602 WRITE_ONCE(channel->enabled, 1);
603 end:
604 mutex_unlock(&sessions_mutex);
605 return ret;
606 }
607
608 int lttng_channel_disable(struct lttng_kernel_channel_common *channel)
609 {
610 int ret = 0;
611
612 mutex_lock(&sessions_mutex);
613 if (is_channel_buffer_metadata(channel)) {
614 ret = -EPERM;
615 goto end;
616 }
617 if (!channel->enabled) {
618 ret = -EEXIST;
619 goto end;
620 }
621 /* Set atomically the state to "disabled" */
622 WRITE_ONCE(channel->enabled, 0);
623 /* Set transient enabler state to "enabled" */
624 channel->priv->tstate = 0;
625 lttng_session_sync_event_enablers(channel->session);
626 end:
627 mutex_unlock(&sessions_mutex);
628 return ret;
629 }
630
631 int lttng_event_enable(struct lttng_kernel_event_common *event)
632 {
633 int ret = 0;
634
635 mutex_lock(&sessions_mutex);
636 switch (event->type) {
637 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
638 {
639 struct lttng_kernel_event_recorder *event_recorder =
640 container_of(event, struct lttng_kernel_event_recorder, parent);
641
642 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
643 ret = -EPERM;
644 goto end;
645 }
646 break;
647 }
648 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
649 switch (event->priv->instrumentation) {
650 case LTTNG_KERNEL_ABI_KRETPROBE:
651 ret = -EINVAL;
652 goto end;
653 default:
654 break;
655 }
656 break;
657 default:
658 break;
659 }
660
661 if (event->enabled) {
662 ret = -EEXIST;
663 goto end;
664 }
665 switch (event->priv->instrumentation) {
666 case LTTNG_KERNEL_ABI_TRACEPOINT:
667 lttng_fallthrough;
668 case LTTNG_KERNEL_ABI_SYSCALL:
669 ret = -EINVAL;
670 break;
671
672 case LTTNG_KERNEL_ABI_KPROBE:
673 lttng_fallthrough;
674 case LTTNG_KERNEL_ABI_UPROBE:
675 WRITE_ONCE(event->enabled, 1);
676 break;
677
678 case LTTNG_KERNEL_ABI_KRETPROBE:
679 ret = lttng_kretprobes_event_enable_state(event, 1);
680 break;
681
682 case LTTNG_KERNEL_ABI_FUNCTION:
683 lttng_fallthrough;
684 case LTTNG_KERNEL_ABI_NOOP:
685 lttng_fallthrough;
686 default:
687 WARN_ON_ONCE(1);
688 ret = -EINVAL;
689 }
690 end:
691 mutex_unlock(&sessions_mutex);
692 return ret;
693 }
694
695 int lttng_event_disable(struct lttng_kernel_event_common *event)
696 {
697 int ret = 0;
698
699 mutex_lock(&sessions_mutex);
700 switch (event->type) {
701 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
702 {
703 struct lttng_kernel_event_recorder *event_recorder =
704 container_of(event, struct lttng_kernel_event_recorder, parent);
705
706 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
707 ret = -EPERM;
708 goto end;
709 }
710 break;
711 }
712 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
713 switch (event->priv->instrumentation) {
714 case LTTNG_KERNEL_ABI_KRETPROBE:
715 ret = -EINVAL;
716 goto end;
717 default:
718 break;
719 }
720 break;
721 default:
722 break;
723 }
724
725 if (!event->enabled) {
726 ret = -EEXIST;
727 goto end;
728 }
729 switch (event->priv->instrumentation) {
730 case LTTNG_KERNEL_ABI_TRACEPOINT:
731 lttng_fallthrough;
732 case LTTNG_KERNEL_ABI_SYSCALL:
733 ret = -EINVAL;
734 break;
735
736 case LTTNG_KERNEL_ABI_KPROBE:
737 lttng_fallthrough;
738 case LTTNG_KERNEL_ABI_UPROBE:
739 WRITE_ONCE(event->enabled, 0);
740 break;
741
742 case LTTNG_KERNEL_ABI_KRETPROBE:
743 ret = lttng_kretprobes_event_enable_state(event, 0);
744 break;
745
746 case LTTNG_KERNEL_ABI_FUNCTION:
747 lttng_fallthrough;
748 case LTTNG_KERNEL_ABI_NOOP:
749 lttng_fallthrough;
750 default:
751 WARN_ON_ONCE(1);
752 ret = -EINVAL;
753 }
754 end:
755 mutex_unlock(&sessions_mutex);
756 return ret;
757 }
758
759 struct lttng_kernel_channel_buffer *lttng_channel_buffer_create(struct lttng_kernel_session *session,
760 const char *transport_name,
761 void *buf_addr,
762 size_t subbuf_size, size_t num_subbuf,
763 unsigned int switch_timer_interval,
764 unsigned int read_timer_interval,
765 enum channel_type channel_type)
766 {
767 struct lttng_kernel_channel_buffer *chan;
768 struct lttng_kernel_channel_buffer_private *chan_priv;
769 struct lttng_transport *transport = NULL;
770
771 mutex_lock(&sessions_mutex);
772 if (session->priv->been_active && channel_type != METADATA_CHANNEL)
773 goto active; /* Refuse to add channel to active session */
774 transport = lttng_transport_find(transport_name);
775 if (!transport) {
776 printk(KERN_WARNING "LTTng: transport %s not found\n",
777 transport_name);
778 goto notransport;
779 }
780 if (!try_module_get(transport->owner)) {
781 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
782 goto notransport;
783 }
784 chan = kzalloc(sizeof(struct lttng_kernel_channel_buffer), GFP_KERNEL);
785 if (!chan)
786 goto nomem;
787 chan_priv = kzalloc(sizeof(struct lttng_kernel_channel_buffer_private), GFP_KERNEL);
788 if (!chan_priv)
789 goto nomem_priv;
790 chan->priv = chan_priv;
791 chan_priv->pub = chan;
792 chan->parent.type = LTTNG_KERNEL_CHANNEL_TYPE_BUFFER;
793 chan->parent.session = session;
794 chan->priv->id = session->priv->free_chan_id++;
795 chan->ops = &transport->ops;
796 /*
797 * Note: the channel creation op already writes into the packet
798 * headers. Therefore the "chan" information used as input
799 * should be already accessible.
800 */
801 chan->priv->rb_chan = transport->ops.priv->channel_create(transport_name,
802 chan, buf_addr, subbuf_size, num_subbuf,
803 switch_timer_interval, read_timer_interval);
804 if (!chan->priv->rb_chan)
805 goto create_error;
806 chan->priv->parent.tstate = 1;
807 chan->parent.enabled = 1;
808 chan->priv->transport = transport;
809 chan->priv->channel_type = channel_type;
810 list_add(&chan->priv->node, &session->priv->chan);
811 mutex_unlock(&sessions_mutex);
812 return chan;
813
814 create_error:
815 kfree(chan_priv);
816 nomem_priv:
817 kfree(chan);
818 nomem:
819 if (transport)
820 module_put(transport->owner);
821 notransport:
822 active:
823 mutex_unlock(&sessions_mutex);
824 return NULL;
825 }
826
827 /*
828 * Only used internally at session destruction for per-cpu channels, and
829 * when metadata channel is released.
830 * Needs to be called with sessions mutex held.
831 */
832 static
833 void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan)
834 {
835 chan->ops->priv->channel_destroy(chan->priv->rb_chan);
836 module_put(chan->priv->transport->owner);
837 list_del(&chan->priv->node);
838 lttng_kernel_destroy_context(chan->priv->ctx);
839 kfree(chan->priv);
840 kfree(chan);
841 }
842
843 void lttng_metadata_channel_destroy(struct lttng_kernel_channel_buffer *chan)
844 {
845 BUG_ON(chan->priv->channel_type != METADATA_CHANNEL);
846
847 /* Protect the metadata cache with the sessions_mutex. */
848 mutex_lock(&sessions_mutex);
849 _lttng_channel_destroy(chan);
850 mutex_unlock(&sessions_mutex);
851 }
852 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
853
854 static
855 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
856 {
857 stream->finalized = 1;
858 wake_up_interruptible(&stream->read_wait);
859 }
860
861 static
862 bool lttng_kernel_event_id_available(struct lttng_event_enabler_common *event_enabler)
863 {
864 struct lttng_kernel_abi_event *event_param = &event_enabler->event_param;
865 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
866
867 switch (event_enabler->enabler_type) {
868 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
869 {
870 struct lttng_event_recorder_enabler *event_recorder_enabler =
871 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
872 struct lttng_kernel_channel_buffer *chan = event_recorder_enabler->chan;
873
874 switch (itype) {
875 case LTTNG_KERNEL_ABI_TRACEPOINT:
876 lttng_fallthrough;
877 case LTTNG_KERNEL_ABI_KPROBE:
878 lttng_fallthrough;
879 case LTTNG_KERNEL_ABI_SYSCALL:
880 lttng_fallthrough;
881 case LTTNG_KERNEL_ABI_UPROBE:
882 if (chan->priv->free_event_id == -1U)
883 return false;
884 return true;
885 case LTTNG_KERNEL_ABI_KRETPROBE:
886 /* kretprobes require 2 event IDs. */
887 if (chan->priv->free_event_id >= -2U)
888 return false;
889 return true;
890 default:
891 WARN_ON_ONCE(1);
892 return false;
893 }
894 }
895 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
896 return true;
897 default:
898 WARN_ON_ONCE(1);
899 return false;
900 }
901 }
902
903 static
904 struct lttng_kernel_event_common *lttng_kernel_event_alloc(struct lttng_event_enabler_common *event_enabler)
905 {
906 struct lttng_kernel_abi_event *event_param = &event_enabler->event_param;
907 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
908
909 switch (event_enabler->enabler_type) {
910 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
911 {
912 struct lttng_event_recorder_enabler *event_recorder_enabler =
913 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
914 struct lttng_kernel_event_recorder *event_recorder;
915 struct lttng_kernel_event_recorder_private *event_recorder_priv;
916 struct lttng_kernel_channel_buffer *chan = event_recorder_enabler->chan;
917
918 event_recorder = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
919 if (!event_recorder)
920 return NULL;
921 event_recorder_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
922 if (!event_recorder_priv) {
923 kmem_cache_free(event_recorder_private_cache, event_recorder);
924 return NULL;
925 }
926 event_recorder_priv->pub = event_recorder;
927 event_recorder_priv->parent.pub = &event_recorder->parent;
928 event_recorder->priv = event_recorder_priv;
929 event_recorder->parent.priv = &event_recorder_priv->parent;
930
931 event_recorder->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
932 event_recorder->parent.run_filter = lttng_kernel_interpret_event_filter;
933 event_recorder->priv->parent.instrumentation = itype;
934 INIT_LIST_HEAD(&event_recorder->priv->parent.filter_bytecode_runtime_head);
935 INIT_LIST_HEAD(&event_recorder->priv->parent.enablers_ref_head);
936
937 event_recorder->chan = chan;
938 event_recorder->priv->id = chan->priv->free_event_id++;
939 return &event_recorder->parent;
940 }
941 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
942 {
943 struct lttng_event_notifier_enabler *event_notifier_enabler =
944 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
945 struct lttng_kernel_event_notifier *event_notifier;
946 struct lttng_kernel_event_notifier_private *event_notifier_priv;
947
948 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
949 if (!event_notifier)
950 return NULL;
951 event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
952 if (!event_notifier_priv) {
953 kmem_cache_free(event_notifier_private_cache, event_notifier);
954 return NULL;
955 }
956 event_notifier_priv->pub = event_notifier;
957 event_notifier_priv->parent.pub = &event_notifier->parent;
958 event_notifier->priv = event_notifier_priv;
959 event_notifier->parent.priv = &event_notifier_priv->parent;
960
961 event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
962 event_notifier->parent.run_filter = lttng_kernel_interpret_event_filter;
963 event_notifier->priv->parent.instrumentation = itype;
964 event_notifier->priv->parent.user_token = event_enabler->user_token;
965 INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
966 INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
967
968 event_notifier->priv->group = event_notifier_enabler->group;
969 event_notifier->priv->error_counter_index = event_notifier_enabler->error_counter_index;
970 event_notifier->priv->num_captures = 0;
971 event_notifier->notification_send = lttng_event_notifier_notification_send;
972 INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
973 return &event_notifier->parent;
974 }
975 default:
976 return NULL;
977 }
978 }
979
980 static
981 void lttng_kernel_event_free(struct lttng_kernel_event_common *event)
982 {
983 switch (event->type) {
984 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
985 {
986 struct lttng_kernel_event_recorder *event_recorder =
987 container_of(event, struct lttng_kernel_event_recorder, parent);
988
989 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
990 kmem_cache_free(event_recorder_cache, event_recorder);
991 break;
992 }
993 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
994 {
995 struct lttng_kernel_event_notifier *event_notifier =
996 container_of(event, struct lttng_kernel_event_notifier, parent);
997
998 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
999 kmem_cache_free(event_notifier_cache, event_notifier);
1000 break;
1001 }
1002 default:
1003 WARN_ON_ONCE(1);
1004 }
1005 }
1006
1007 static
1008 int lttng_kernel_event_notifier_clear_error_counter(struct lttng_kernel_event_common *event)
1009 {
1010 switch (event->type) {
1011 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1012 return 0;
1013 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1014 {
1015 struct lttng_kernel_event_notifier *event_notifier =
1016 container_of(event, struct lttng_kernel_event_notifier, parent);
1017 struct lttng_counter *error_counter;
1018 struct lttng_event_notifier_group *event_notifier_group = event_notifier->priv->group;
1019 size_t dimension_index[1];
1020 int ret;
1021
1022 /*
1023 * Clear the error counter bucket. The sessiond keeps track of which
1024 * bucket is currently in use. We trust it. The session lock
1025 * synchronizes against concurrent creation of the error
1026 * counter.
1027 */
1028 error_counter = event_notifier_group->error_counter;
1029 if (!error_counter)
1030 return 0;
1031 /*
1032 * Check that the index is within the boundary of the counter.
1033 */
1034 if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
1035 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1036 event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
1037 return -EINVAL;
1038 }
1039
1040 dimension_index[0] = event_notifier->priv->error_counter_index;
1041 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1042 if (ret) {
1043 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1044 event_notifier->priv->error_counter_index);
1045 return -EINVAL;
1046 }
1047 return 0;
1048 }
1049 default:
1050 return -EINVAL;
1051 }
1052 }
1053
1054 /*
1055 * Supports event creation while tracing session is active.
1056 * Needs to be called with sessions mutex held.
1057 */
1058 struct lttng_kernel_event_common *_lttng_kernel_event_create(struct lttng_event_enabler_common *event_enabler,
1059 const struct lttng_kernel_event_desc *event_desc)
1060 {
1061 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(event_enabler);
1062 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(event_enabler);
1063 struct lttng_kernel_abi_event *event_param = &event_enabler->event_param;
1064 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
1065 struct lttng_kernel_event_common_private *event_priv;
1066 struct lttng_kernel_event_common *event;
1067 const char *event_name;
1068 struct hlist_head *head;
1069 int ret;
1070
1071 if (!lttng_kernel_event_id_available(event_enabler)) {
1072 ret = -EMFILE;
1073 goto full;
1074 }
1075
1076 switch (itype) {
1077 case LTTNG_KERNEL_ABI_TRACEPOINT:
1078 event_name = event_desc->event_name;
1079 break;
1080
1081 case LTTNG_KERNEL_ABI_KPROBE:
1082 lttng_fallthrough;
1083 case LTTNG_KERNEL_ABI_UPROBE:
1084 lttng_fallthrough;
1085 case LTTNG_KERNEL_ABI_KRETPROBE:
1086 lttng_fallthrough;
1087 case LTTNG_KERNEL_ABI_SYSCALL:
1088 event_name = event_param->name;
1089 break;
1090
1091 case LTTNG_KERNEL_ABI_FUNCTION:
1092 lttng_fallthrough;
1093 case LTTNG_KERNEL_ABI_NOOP:
1094 lttng_fallthrough;
1095 default:
1096 WARN_ON_ONCE(1);
1097 ret = -EINVAL;
1098 goto type_error;
1099 }
1100
1101 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, event_name);
1102 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
1103 if (lttng_event_enabler_event_name_match_event(event_enabler, event_name, event_priv->pub)) {
1104 ret = -EEXIST;
1105 goto exist;
1106 }
1107 }
1108
1109 event = lttng_kernel_event_alloc(event_enabler);
1110 if (!event) {
1111 ret = -ENOMEM;
1112 goto alloc_error;
1113 }
1114
1115 switch (itype) {
1116 case LTTNG_KERNEL_ABI_TRACEPOINT:
1117 /* Event will be enabled by enabler sync. */
1118 event->enabled = 0;
1119 event->priv->registered = 0;
1120 event->priv->desc = lttng_event_desc_get(event_name);
1121 if (!event->priv->desc) {
1122 ret = -ENOENT;
1123 goto register_error;
1124 }
1125 /* Populate lttng_event structure before event registration. */
1126 smp_wmb();
1127 break;
1128
1129 case LTTNG_KERNEL_ABI_KPROBE:
1130 /*
1131 * Needs to be explicitly enabled after creation, since
1132 * we may want to apply filters.
1133 */
1134 event->enabled = 0;
1135 event->priv->registered = 1;
1136 /*
1137 * Populate lttng_event structure before event
1138 * registration.
1139 */
1140 smp_wmb();
1141 ret = lttng_kprobes_register_event(event_name,
1142 event_param->u.kprobe.symbol_name,
1143 event_param->u.kprobe.offset,
1144 event_param->u.kprobe.addr,
1145 event);
1146 if (ret) {
1147 ret = -EINVAL;
1148 goto register_error;
1149 }
1150 ret = try_module_get(event->priv->desc->owner);
1151 WARN_ON_ONCE(!ret);
1152 break;
1153
1154 case LTTNG_KERNEL_ABI_KRETPROBE:
1155 {
1156 struct lttng_kernel_event_common *event_return;
1157
1158 /* kretprobe defines 2 events */
1159 /*
1160 * Needs to be explicitly enabled after creation, since
1161 * we may want to apply filters.
1162 */
1163 event->enabled = 0;
1164 event->priv->registered = 1;
1165
1166 event_return = lttng_kernel_event_alloc(event_enabler);
1167 if (!event) {
1168 ret = -ENOMEM;
1169 goto alloc_error;
1170 }
1171
1172 event_return->enabled = 0;
1173 event_return->priv->registered = 1;
1174
1175 /*
1176 * Populate lttng_event structure before kretprobe registration.
1177 */
1178 smp_wmb();
1179 ret = lttng_kretprobes_register(event_name,
1180 event_param->u.kretprobe.symbol_name,
1181 event_param->u.kretprobe.offset,
1182 event_param->u.kretprobe.addr,
1183 event, event_return);
1184 if (ret) {
1185 lttng_kernel_event_free(event_return);
1186 ret = -EINVAL;
1187 goto register_error;
1188 }
1189 /* Take 2 refs on the module: one per event. */
1190 ret = try_module_get(event->priv->desc->owner);
1191 WARN_ON_ONCE(!ret);
1192 ret = try_module_get(event_return->priv->desc->owner);
1193 WARN_ON_ONCE(!ret);
1194 ret = _lttng_event_recorder_metadata_statedump(event_return);
1195 WARN_ON_ONCE(ret > 0);
1196 if (ret) {
1197 lttng_kernel_event_free(event_return);
1198 module_put(event_return->priv->desc->owner);
1199 module_put(event->priv->desc->owner);
1200 goto statedump_error;
1201 }
1202 list_add(&event_return->priv->node, event_list_head);
1203 break;
1204 }
1205
1206 case LTTNG_KERNEL_ABI_SYSCALL:
1207 /*
1208 * Needs to be explicitly enabled after creation, since
1209 * we may want to apply filters.
1210 */
1211 event->enabled = 0;
1212 event->priv->registered = 0;
1213 event->priv->desc = event_desc;
1214 switch (event_param->u.syscall.entryexit) {
1215 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1216 ret = -EINVAL;
1217 goto register_error;
1218 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1219 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1220 break;
1221 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1222 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1223 break;
1224 }
1225 switch (event_param->u.syscall.abi) {
1226 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1227 ret = -EINVAL;
1228 goto register_error;
1229 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1230 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1231 break;
1232 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1233 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1234 break;
1235 }
1236 if (!event->priv->desc) {
1237 ret = -EINVAL;
1238 goto register_error;
1239 }
1240 break;
1241
1242 case LTTNG_KERNEL_ABI_UPROBE:
1243 /*
1244 * Needs to be explicitly enabled after creation, since
1245 * we may want to apply filters.
1246 */
1247 event->enabled = 0;
1248 event->priv->registered = 1;
1249
1250 /*
1251 * Populate lttng_event structure before event
1252 * registration.
1253 */
1254 smp_wmb();
1255
1256 ret = lttng_uprobes_register_event(event_param->name,
1257 event_param->u.uprobe.fd,
1258 event);
1259 if (ret)
1260 goto register_error;
1261 ret = try_module_get(event->priv->desc->owner);
1262 WARN_ON_ONCE(!ret);
1263 break;
1264
1265 default:
1266 WARN_ON_ONCE(1);
1267 ret = -EINVAL;
1268 goto register_error;
1269 }
1270
1271 ret = _lttng_event_recorder_metadata_statedump(event);
1272 WARN_ON_ONCE(ret > 0);
1273 if (ret) {
1274 goto statedump_error;
1275 }
1276
1277 ret = lttng_kernel_event_notifier_clear_error_counter(event);
1278 if (ret)
1279 goto register_error;
1280
1281 hlist_add_head(&event->priv->hlist_node, head);
1282 list_add(&event->priv->node, event_list_head);
1283
1284 return event;
1285
1286 statedump_error:
1287 /* If a statedump error occurs, events will not be readable. */
1288 register_error:
1289 lttng_kernel_event_free(event);
1290 alloc_error:
1291 exist:
1292 type_error:
1293 full:
1294 return ERR_PTR(ret);
1295 }
1296
1297 struct lttng_kernel_event_common *lttng_kernel_event_create(struct lttng_event_enabler_common *event_enabler,
1298 const struct lttng_kernel_event_desc *event_desc)
1299 {
1300 struct lttng_kernel_event_common *event;
1301
1302 mutex_lock(&sessions_mutex);
1303 event = _lttng_kernel_event_create(event_enabler, event_desc);
1304 mutex_unlock(&sessions_mutex);
1305 return event;
1306 }
1307
1308 int lttng_kernel_counter_read(struct lttng_counter *counter,
1309 const size_t *dim_indexes, int32_t cpu,
1310 int64_t *val, bool *overflow, bool *underflow)
1311 {
1312 return counter->ops->counter_read(counter->counter, dim_indexes,
1313 cpu, val, overflow, underflow);
1314 }
1315
1316 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1317 const size_t *dim_indexes, int64_t *val,
1318 bool *overflow, bool *underflow)
1319 {
1320 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1321 val, overflow, underflow);
1322 }
1323
1324 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1325 const size_t *dim_indexes)
1326 {
1327 return counter->ops->counter_clear(counter->counter, dim_indexes);
1328 }
1329
1330 /* Only used for tracepoints and system calls for now. */
1331 static
1332 void register_event(struct lttng_kernel_event_common *event)
1333 {
1334 const struct lttng_kernel_event_desc *desc;
1335 int ret = -EINVAL;
1336
1337 WARN_ON_ONCE(event->priv->registered);
1338
1339 desc = event->priv->desc;
1340 switch (event->priv->instrumentation) {
1341 case LTTNG_KERNEL_ABI_TRACEPOINT:
1342 ret = lttng_tracepoint_probe_register(desc->event_kname,
1343 desc->tp_class->probe_callback,
1344 event);
1345 break;
1346
1347 case LTTNG_KERNEL_ABI_SYSCALL:
1348 ret = lttng_syscall_filter_enable_event(event);
1349 break;
1350
1351 case LTTNG_KERNEL_ABI_KPROBE:
1352 lttng_fallthrough;
1353 case LTTNG_KERNEL_ABI_UPROBE:
1354 ret = 0;
1355 break;
1356
1357 case LTTNG_KERNEL_ABI_KRETPROBE:
1358 switch (event->type) {
1359 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1360 ret = 0;
1361 break;
1362 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1363 WARN_ON_ONCE(1);
1364 break;
1365 }
1366 break;
1367
1368 case LTTNG_KERNEL_ABI_FUNCTION:
1369 lttng_fallthrough;
1370 case LTTNG_KERNEL_ABI_NOOP:
1371 lttng_fallthrough;
1372 default:
1373 WARN_ON_ONCE(1);
1374 }
1375 WARN_ON_ONCE(ret);
1376 if (!ret)
1377 event->priv->registered = 1;
1378 }
1379
1380 static
1381 void unregister_event(struct lttng_kernel_event_common *event)
1382 {
1383 struct lttng_kernel_event_common_private *event_priv = event->priv;
1384 const struct lttng_kernel_event_desc *desc;
1385 int ret = -EINVAL;
1386
1387 WARN_ON_ONCE(!event->priv->registered);
1388
1389 desc = event_priv->desc;
1390 switch (event_priv->instrumentation) {
1391 case LTTNG_KERNEL_ABI_TRACEPOINT:
1392 ret = lttng_tracepoint_probe_unregister(event_priv->desc->event_kname,
1393 event_priv->desc->tp_class->probe_callback,
1394 event);
1395 break;
1396
1397 case LTTNG_KERNEL_ABI_KPROBE:
1398 lttng_kprobes_unregister_event(event);
1399 ret = 0;
1400 break;
1401
1402 case LTTNG_KERNEL_ABI_KRETPROBE:
1403 switch (event->type) {
1404 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1405 lttng_kretprobes_unregister(event);
1406 ret = 0;
1407 break;
1408 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1409 WARN_ON_ONCE(1);
1410 break;
1411 }
1412 break;
1413
1414 case LTTNG_KERNEL_ABI_SYSCALL:
1415 ret = lttng_syscall_filter_disable_event(event);
1416 break;
1417
1418 case LTTNG_KERNEL_ABI_NOOP:
1419 switch (event->type) {
1420 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1421 ret = 0;
1422 break;
1423 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1424 WARN_ON_ONCE(1);
1425 break;
1426 }
1427 break;
1428
1429 case LTTNG_KERNEL_ABI_UPROBE:
1430 lttng_uprobes_unregister_event(event);
1431 ret = 0;
1432 break;
1433
1434 case LTTNG_KERNEL_ABI_FUNCTION:
1435 lttng_fallthrough;
1436 default:
1437 WARN_ON_ONCE(1);
1438 }
1439 WARN_ON_ONCE(ret);
1440 if (!ret)
1441 event_priv->registered = 0;
1442 }
1443
1444 static
1445 void _lttng_event_unregister(struct lttng_kernel_event_common *event)
1446 {
1447 if (event->priv->registered)
1448 unregister_event(event);
1449 }
1450
1451 /*
1452 * Only used internally at session destruction.
1453 */
1454 static
1455 void _lttng_event_destroy(struct lttng_kernel_event_common *event)
1456 {
1457 struct lttng_kernel_event_common_private *event_priv = event->priv;
1458 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1459
1460 lttng_free_event_filter_runtime(event);
1461 /* Free event enabler refs */
1462 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1463 &event_priv->enablers_ref_head, node)
1464 kfree(enabler_ref);
1465
1466 switch (event->type) {
1467 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1468 {
1469 struct lttng_kernel_event_recorder *event_recorder =
1470 container_of(event, struct lttng_kernel_event_recorder, parent);
1471
1472 switch (event_priv->instrumentation) {
1473 case LTTNG_KERNEL_ABI_TRACEPOINT:
1474 lttng_event_desc_put(event_priv->desc);
1475 break;
1476
1477 case LTTNG_KERNEL_ABI_KPROBE:
1478 module_put(event_priv->desc->owner);
1479 lttng_kprobes_destroy_event_private(&event_recorder->parent);
1480 break;
1481
1482 case LTTNG_KERNEL_ABI_KRETPROBE:
1483 module_put(event_priv->desc->owner);
1484 lttng_kretprobes_destroy_private(&event_recorder->parent);
1485 break;
1486
1487 case LTTNG_KERNEL_ABI_SYSCALL:
1488 break;
1489
1490 case LTTNG_KERNEL_ABI_UPROBE:
1491 module_put(event_priv->desc->owner);
1492 lttng_uprobes_destroy_event_private(&event_recorder->parent);
1493 break;
1494
1495 case LTTNG_KERNEL_ABI_FUNCTION:
1496 lttng_fallthrough;
1497 case LTTNG_KERNEL_ABI_NOOP:
1498 lttng_fallthrough;
1499 default:
1500 WARN_ON_ONCE(1);
1501 }
1502 list_del(&event_recorder->priv->parent.node);
1503 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
1504 kmem_cache_free(event_recorder_cache, event_recorder);
1505 break;
1506 }
1507 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1508 {
1509 struct lttng_kernel_event_notifier *event_notifier =
1510 container_of(event, struct lttng_kernel_event_notifier, parent);
1511
1512 switch (event_notifier->priv->parent.instrumentation) {
1513 case LTTNG_KERNEL_ABI_TRACEPOINT:
1514 lttng_event_desc_put(event_notifier->priv->parent.desc);
1515 break;
1516
1517 case LTTNG_KERNEL_ABI_KPROBE:
1518 module_put(event_notifier->priv->parent.desc->owner);
1519 lttng_kprobes_destroy_event_private(&event_notifier->parent);
1520 break;
1521
1522 case LTTNG_KERNEL_ABI_SYSCALL:
1523 break;
1524
1525 case LTTNG_KERNEL_ABI_UPROBE:
1526 module_put(event_notifier->priv->parent.desc->owner);
1527 lttng_uprobes_destroy_event_private(&event_notifier->parent);
1528 break;
1529
1530 case LTTNG_KERNEL_ABI_KRETPROBE:
1531 lttng_fallthrough;
1532 case LTTNG_KERNEL_ABI_FUNCTION:
1533 lttng_fallthrough;
1534 case LTTNG_KERNEL_ABI_NOOP:
1535 lttng_fallthrough;
1536 default:
1537 WARN_ON_ONCE(1);
1538 }
1539 list_del(&event_notifier->priv->parent.node);
1540 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1541 kmem_cache_free(event_notifier_cache, event_notifier);
1542 break;
1543 }
1544 default:
1545 WARN_ON_ONCE(1);
1546 }
1547 }
1548
1549 struct lttng_kernel_id_tracker *get_tracker(struct lttng_kernel_session *session,
1550 enum tracker_type tracker_type)
1551 {
1552 switch (tracker_type) {
1553 case TRACKER_PID:
1554 return &session->pid_tracker;
1555 case TRACKER_VPID:
1556 return &session->vpid_tracker;
1557 case TRACKER_UID:
1558 return &session->uid_tracker;
1559 case TRACKER_VUID:
1560 return &session->vuid_tracker;
1561 case TRACKER_GID:
1562 return &session->gid_tracker;
1563 case TRACKER_VGID:
1564 return &session->vgid_tracker;
1565 default:
1566 WARN_ON_ONCE(1);
1567 return NULL;
1568 }
1569 }
1570
1571 int lttng_session_track_id(struct lttng_kernel_session *session,
1572 enum tracker_type tracker_type, int id)
1573 {
1574 struct lttng_kernel_id_tracker *tracker;
1575 int ret;
1576
1577 tracker = get_tracker(session, tracker_type);
1578 if (!tracker)
1579 return -EINVAL;
1580 if (id < -1)
1581 return -EINVAL;
1582 mutex_lock(&sessions_mutex);
1583 if (id == -1) {
1584 /* track all ids: destroy tracker. */
1585 lttng_id_tracker_destroy(tracker, true);
1586 ret = 0;
1587 } else {
1588 ret = lttng_id_tracker_add(tracker, id);
1589 }
1590 mutex_unlock(&sessions_mutex);
1591 return ret;
1592 }
1593
1594 int lttng_session_untrack_id(struct lttng_kernel_session *session,
1595 enum tracker_type tracker_type, int id)
1596 {
1597 struct lttng_kernel_id_tracker *tracker;
1598 int ret;
1599
1600 tracker = get_tracker(session, tracker_type);
1601 if (!tracker)
1602 return -EINVAL;
1603 if (id < -1)
1604 return -EINVAL;
1605 mutex_lock(&sessions_mutex);
1606 if (id == -1) {
1607 /* untrack all ids: replace by empty tracker. */
1608 ret = lttng_id_tracker_empty_set(tracker);
1609 } else {
1610 ret = lttng_id_tracker_del(tracker, id);
1611 }
1612 mutex_unlock(&sessions_mutex);
1613 return ret;
1614 }
1615
1616 static
1617 void *id_list_start(struct seq_file *m, loff_t *pos)
1618 {
1619 struct lttng_kernel_id_tracker *id_tracker = m->private;
1620 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1621 struct lttng_id_hash_node *e;
1622 int iter = 0, i;
1623
1624 mutex_lock(&sessions_mutex);
1625 if (id_tracker_p) {
1626 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1627 struct hlist_head *head = &id_tracker_p->id_hash[i];
1628
1629 lttng_hlist_for_each_entry(e, head, hlist) {
1630 if (iter++ >= *pos)
1631 return e;
1632 }
1633 }
1634 } else {
1635 /* ID tracker disabled. */
1636 if (iter >= *pos && iter == 0) {
1637 return id_tracker_p; /* empty tracker */
1638 }
1639 iter++;
1640 }
1641 /* End of list */
1642 return NULL;
1643 }
1644
1645 /* Called with sessions_mutex held. */
1646 static
1647 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1648 {
1649 struct lttng_kernel_id_tracker *id_tracker = m->private;
1650 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1651 struct lttng_id_hash_node *e;
1652 int iter = 0, i;
1653
1654 (*ppos)++;
1655 if (id_tracker_p) {
1656 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1657 struct hlist_head *head = &id_tracker_p->id_hash[i];
1658
1659 lttng_hlist_for_each_entry(e, head, hlist) {
1660 if (iter++ >= *ppos)
1661 return e;
1662 }
1663 }
1664 } else {
1665 /* ID tracker disabled. */
1666 if (iter >= *ppos && iter == 0)
1667 return p; /* empty tracker */
1668 iter++;
1669 }
1670
1671 /* End of list */
1672 return NULL;
1673 }
1674
1675 static
1676 void id_list_stop(struct seq_file *m, void *p)
1677 {
1678 mutex_unlock(&sessions_mutex);
1679 }
1680
1681 static
1682 int id_list_show(struct seq_file *m, void *p)
1683 {
1684 struct lttng_kernel_id_tracker *id_tracker = m->private;
1685 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1686 int id;
1687
1688 if (p == id_tracker_p) {
1689 /* Tracker disabled. */
1690 id = -1;
1691 } else {
1692 const struct lttng_id_hash_node *e = p;
1693
1694 id = lttng_id_tracker_get_node_id(e);
1695 }
1696 switch (id_tracker->priv->tracker_type) {
1697 case TRACKER_PID:
1698 seq_printf(m, "process { pid = %d; };\n", id);
1699 break;
1700 case TRACKER_VPID:
1701 seq_printf(m, "process { vpid = %d; };\n", id);
1702 break;
1703 case TRACKER_UID:
1704 seq_printf(m, "user { uid = %d; };\n", id);
1705 break;
1706 case TRACKER_VUID:
1707 seq_printf(m, "user { vuid = %d; };\n", id);
1708 break;
1709 case TRACKER_GID:
1710 seq_printf(m, "group { gid = %d; };\n", id);
1711 break;
1712 case TRACKER_VGID:
1713 seq_printf(m, "group { vgid = %d; };\n", id);
1714 break;
1715 default:
1716 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1717 }
1718 return 0;
1719 }
1720
1721 static
1722 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1723 .start = id_list_start,
1724 .next = id_list_next,
1725 .stop = id_list_stop,
1726 .show = id_list_show,
1727 };
1728
1729 static
1730 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1731 {
1732 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1733 }
1734
1735 static
1736 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1737 {
1738 struct seq_file *m = file->private_data;
1739 struct lttng_kernel_id_tracker *id_tracker = m->private;
1740 int ret;
1741
1742 WARN_ON_ONCE(!id_tracker);
1743 ret = seq_release(inode, file);
1744 if (!ret)
1745 fput(id_tracker->priv->session->priv->file);
1746 return ret;
1747 }
1748
1749 const struct file_operations lttng_tracker_ids_list_fops = {
1750 .owner = THIS_MODULE,
1751 .open = lttng_tracker_ids_list_open,
1752 .read = seq_read,
1753 .llseek = seq_lseek,
1754 .release = lttng_tracker_ids_list_release,
1755 };
1756
1757 int lttng_session_list_tracker_ids(struct lttng_kernel_session *session,
1758 enum tracker_type tracker_type)
1759 {
1760 struct file *tracker_ids_list_file;
1761 struct seq_file *m;
1762 int file_fd, ret;
1763
1764 file_fd = get_unused_fd_flags(0);
1765 if (file_fd < 0) {
1766 ret = file_fd;
1767 goto fd_error;
1768 }
1769
1770 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1771 &lttng_tracker_ids_list_fops,
1772 NULL, O_RDWR);
1773 if (IS_ERR(tracker_ids_list_file)) {
1774 ret = PTR_ERR(tracker_ids_list_file);
1775 goto file_error;
1776 }
1777 if (!atomic_long_add_unless(&session->priv->file->f_count, 1, LONG_MAX)) {
1778 ret = -EOVERFLOW;
1779 goto refcount_error;
1780 }
1781 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1782 if (ret < 0)
1783 goto open_error;
1784 m = tracker_ids_list_file->private_data;
1785
1786 m->private = get_tracker(session, tracker_type);
1787 BUG_ON(!m->private);
1788 fd_install(file_fd, tracker_ids_list_file);
1789
1790 return file_fd;
1791
1792 open_error:
1793 atomic_long_dec(&session->priv->file->f_count);
1794 refcount_error:
1795 fput(tracker_ids_list_file);
1796 file_error:
1797 put_unused_fd(file_fd);
1798 fd_error:
1799 return ret;
1800 }
1801
1802 /*
1803 * Enabler management.
1804 */
1805 static
1806 int lttng_match_enabler_star_glob(const char *desc_name,
1807 const char *pattern)
1808 {
1809 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1810 desc_name, LTTNG_SIZE_MAX))
1811 return 0;
1812 return 1;
1813 }
1814
1815 static
1816 int lttng_match_enabler_name(const char *desc_name,
1817 const char *name)
1818 {
1819 if (strcmp(desc_name, name))
1820 return 0;
1821 return 1;
1822 }
1823
1824 static
1825 int lttng_desc_match_enabler_check(const struct lttng_kernel_event_desc *desc,
1826 struct lttng_event_enabler_common *enabler)
1827 {
1828 const char *desc_name, *enabler_name;
1829 bool compat = false, entry = false;
1830
1831 enabler_name = enabler->event_param.name;
1832 switch (enabler->event_param.instrumentation) {
1833 case LTTNG_KERNEL_ABI_TRACEPOINT:
1834 desc_name = desc->event_name;
1835 switch (enabler->format_type) {
1836 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1837 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1838 case LTTNG_ENABLER_FORMAT_NAME:
1839 return lttng_match_enabler_name(desc_name, enabler_name);
1840 default:
1841 return -EINVAL;
1842 }
1843 break;
1844
1845 case LTTNG_KERNEL_ABI_SYSCALL:
1846 desc_name = desc->event_name;
1847 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1848 desc_name += strlen("compat_");
1849 compat = true;
1850 }
1851 if (!strncmp(desc_name, "syscall_exit_",
1852 strlen("syscall_exit_"))) {
1853 desc_name += strlen("syscall_exit_");
1854 } else if (!strncmp(desc_name, "syscall_entry_",
1855 strlen("syscall_entry_"))) {
1856 desc_name += strlen("syscall_entry_");
1857 entry = true;
1858 } else {
1859 WARN_ON_ONCE(1);
1860 return -EINVAL;
1861 }
1862 switch (enabler->event_param.u.syscall.entryexit) {
1863 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1864 break;
1865 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1866 if (!entry)
1867 return 0;
1868 break;
1869 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1870 if (entry)
1871 return 0;
1872 break;
1873 default:
1874 return -EINVAL;
1875 }
1876 switch (enabler->event_param.u.syscall.abi) {
1877 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1878 break;
1879 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1880 if (compat)
1881 return 0;
1882 break;
1883 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1884 if (!compat)
1885 return 0;
1886 break;
1887 default:
1888 return -EINVAL;
1889 }
1890 switch (enabler->event_param.u.syscall.match) {
1891 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
1892 switch (enabler->format_type) {
1893 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1894 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1895 case LTTNG_ENABLER_FORMAT_NAME:
1896 return lttng_match_enabler_name(desc_name, enabler_name);
1897 default:
1898 return -EINVAL;
1899 }
1900 break;
1901 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
1902 return -EINVAL; /* Not implemented. */
1903 default:
1904 return -EINVAL;
1905 }
1906 break;
1907
1908 default:
1909 WARN_ON_ONCE(1);
1910 return -EINVAL;
1911 }
1912 }
1913
1914 bool lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
1915 struct lttng_event_enabler_common *enabler)
1916 {
1917 int ret;
1918
1919 ret = lttng_desc_match_enabler_check(desc, enabler);
1920 if (ret < 0) {
1921 WARN_ON_ONCE(1);
1922 return false;
1923 }
1924 return ret;
1925 }
1926
1927 bool lttng_event_enabler_match_event(struct lttng_event_enabler_common *event_enabler,
1928 struct lttng_kernel_event_common *event)
1929 {
1930 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
1931 return false;
1932
1933 switch (event_enabler->enabler_type) {
1934 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
1935 {
1936 struct lttng_event_recorder_enabler *event_recorder_enabler =
1937 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
1938 struct lttng_kernel_event_recorder *event_recorder =
1939 container_of(event, struct lttng_kernel_event_recorder, parent);
1940
1941 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
1942 && event_recorder->chan == event_recorder_enabler->chan)
1943 return true;
1944 else
1945 return false;
1946 }
1947 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
1948 {
1949 struct lttng_event_notifier_enabler *event_notifier_enabler =
1950 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
1951 struct lttng_kernel_event_notifier *event_notifier =
1952 container_of(event, struct lttng_kernel_event_notifier, parent);
1953
1954 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
1955 && event_notifier->priv->group == event_notifier_enabler->group
1956 && event->priv->user_token == event_enabler->user_token)
1957 return true;
1958 else
1959 return false;
1960 }
1961 default:
1962 WARN_ON_ONCE(1);
1963 return false;
1964 }
1965 }
1966
1967 bool lttng_event_enabler_desc_match_event(struct lttng_event_enabler_common *event_enabler,
1968 const struct lttng_kernel_event_desc *desc,
1969 struct lttng_kernel_event_common *event)
1970 {
1971 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
1972 return false;
1973
1974 switch (event_enabler->enabler_type) {
1975 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
1976 {
1977 struct lttng_event_recorder_enabler *event_recorder_enabler =
1978 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
1979 struct lttng_kernel_event_recorder *event_recorder =
1980 container_of(event, struct lttng_kernel_event_recorder, parent);
1981
1982 if (event->priv->desc == desc && event_recorder->chan == event_recorder_enabler->chan)
1983 return true;
1984 else
1985 return false;
1986 }
1987 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
1988 {
1989 struct lttng_event_notifier_enabler *event_notifier_enabler =
1990 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
1991 struct lttng_kernel_event_notifier *event_notifier =
1992 container_of(event, struct lttng_kernel_event_notifier, parent);
1993
1994 if (event->priv->desc == desc
1995 && event_notifier->priv->group == event_notifier_enabler->group
1996 && event->priv->user_token == event_enabler->user_token)
1997 return true;
1998 else
1999 return false;
2000 }
2001 default:
2002 WARN_ON_ONCE(1);
2003 return false;
2004 }
2005 }
2006
2007 bool lttng_event_enabler_event_name_match_event(struct lttng_event_enabler_common *event_enabler,
2008 const char *event_name,
2009 struct lttng_kernel_event_common *event)
2010 {
2011 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2012 return false;
2013
2014 switch (event_enabler->enabler_type) {
2015 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2016 {
2017 struct lttng_event_recorder_enabler *event_recorder_enabler =
2018 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2019 struct lttng_kernel_event_recorder *event_recorder =
2020 container_of(event, struct lttng_kernel_event_recorder, parent);
2021
2022 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2023 && event_recorder->chan == event_recorder_enabler->chan)
2024 return true;
2025 else
2026 return false;
2027 }
2028 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2029 {
2030 struct lttng_event_notifier_enabler *event_notifier_enabler =
2031 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2032 struct lttng_kernel_event_notifier *event_notifier =
2033 container_of(event, struct lttng_kernel_event_notifier, parent);
2034
2035 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2036 && event_notifier->priv->group == event_notifier_enabler->group
2037 && event->priv->user_token == event_enabler->user_token)
2038 return true;
2039 else
2040 return false;
2041 }
2042 default:
2043 WARN_ON_ONCE(1);
2044 return false;
2045 }
2046 }
2047
2048 static
2049 struct lttng_enabler_ref *lttng_enabler_ref(
2050 struct list_head *enablers_ref_list,
2051 struct lttng_event_enabler_common *enabler)
2052 {
2053 struct lttng_enabler_ref *enabler_ref;
2054
2055 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2056 if (enabler_ref->ref == enabler)
2057 return enabler_ref;
2058 }
2059 return NULL;
2060 }
2061
2062 static
2063 void lttng_event_enabler_create_tracepoint_events_if_missing(struct lttng_event_enabler_common *event_enabler)
2064 {
2065 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(event_enabler);
2066 struct lttng_kernel_probe_desc *probe_desc;
2067 const struct lttng_kernel_event_desc *desc;
2068 struct list_head *probe_list;
2069 int i;
2070
2071 probe_list = lttng_get_probe_list_head();
2072 /*
2073 * For each probe event, if we find that a probe event matches
2074 * our enabler, create an associated lttng_event if not
2075 * already present.
2076 */
2077 list_for_each_entry(probe_desc, probe_list, head) {
2078 for (i = 0; i < probe_desc->nr_events; i++) {
2079 bool found = false;
2080 struct hlist_head *head;
2081 struct lttng_kernel_event_common *event;
2082 struct lttng_kernel_event_common_private *event_priv;
2083
2084 desc = probe_desc->event_desc[i];
2085 if (!lttng_desc_match_enabler(desc, event_enabler))
2086 continue;
2087
2088 /*
2089 * Check if already created.
2090 */
2091 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
2092 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
2093 if (lttng_event_enabler_desc_match_event(event_enabler, desc, event_priv->pub)) {
2094 found = true;
2095 break;
2096 }
2097 }
2098 if (found)
2099 continue;
2100
2101 /*
2102 * We need to create an event for this event probe.
2103 */
2104 event = _lttng_kernel_event_create(event_enabler, desc);
2105 if (IS_ERR(event)) {
2106 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2107 probe_desc->event_desc[i]->event_name);
2108 }
2109 }
2110 }
2111 }
2112
2113 /*
2114 * Create event if it is missing and present in the list of tracepoint probes.
2115 * Should be called with sessions mutex held.
2116 */
2117 static
2118 void lttng_event_enabler_create_events_if_missing(struct lttng_event_enabler_common *event_enabler)
2119 {
2120 int ret;
2121
2122 switch (event_enabler->event_param.instrumentation) {
2123 case LTTNG_KERNEL_ABI_TRACEPOINT:
2124 lttng_event_enabler_create_tracepoint_events_if_missing(event_enabler);
2125 break;
2126
2127 case LTTNG_KERNEL_ABI_SYSCALL:
2128 ret = lttng_event_enabler_create_syscall_events_if_missing(event_enabler);
2129 WARN_ON_ONCE(ret);
2130 break;
2131
2132 default:
2133 WARN_ON_ONCE(1);
2134 break;
2135 }
2136 }
2137
2138 static
2139 void lttng_event_enabler_init_event_filter(struct lttng_event_enabler_common *event_enabler,
2140 struct lttng_kernel_event_common *event)
2141 {
2142 /* Link filter bytecodes if not linked yet. */
2143 lttng_enabler_link_bytecode(event->priv->desc, lttng_static_ctx,
2144 &event->priv->filter_bytecode_runtime_head, &event_enabler->filter_bytecode_head);
2145 }
2146
2147 static
2148 void lttng_event_enabler_init_event_capture(struct lttng_event_enabler_common *event_enabler,
2149 struct lttng_kernel_event_common *event)
2150 {
2151 switch (event_enabler->enabler_type) {
2152 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2153 break;
2154 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2155 {
2156 struct lttng_event_notifier_enabler *event_notifier_enabler =
2157 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2158 struct lttng_kernel_event_notifier *event_notifier =
2159 container_of(event, struct lttng_kernel_event_notifier, parent);
2160
2161 /* Link capture bytecodes if not linked yet. */
2162 lttng_enabler_link_bytecode(event->priv->desc,
2163 lttng_static_ctx, &event_notifier->priv->capture_bytecode_runtime_head,
2164 &event_notifier_enabler->capture_bytecode_head);
2165 event_notifier->priv->num_captures = event_notifier_enabler->num_captures;
2166 break;
2167 }
2168 default:
2169 WARN_ON_ONCE(1);
2170 }
2171 }
2172
2173 /*
2174 * Create events associated with an event_enabler (if not already present),
2175 * and add backward reference from the event to the enabler.
2176 * Should be called with sessions mutex held.
2177 */
2178 static
2179 int lttng_event_enabler_ref_events(struct lttng_event_enabler_common *event_enabler)
2180 {
2181 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(event_enabler);
2182 struct lttng_kernel_event_common_private *event_priv;
2183
2184 lttng_syscall_table_set_wildcard_all(event_enabler);
2185
2186 /* First ensure that probe events are created for this enabler. */
2187 lttng_event_enabler_create_events_if_missing(event_enabler);
2188
2189 /* Link the created event with its associated enabler. */
2190 list_for_each_entry(event_priv, event_list_head, node) {
2191 struct lttng_kernel_event_common *event = event_priv->pub;
2192 struct lttng_enabler_ref *enabler_ref;
2193
2194 if (!lttng_event_enabler_match_event(event_enabler, event))
2195 continue;
2196
2197 enabler_ref = lttng_enabler_ref(&event_priv->enablers_ref_head, event_enabler);
2198 if (!enabler_ref) {
2199 /*
2200 * If no backward ref, create it.
2201 * Add backward ref from event_notifier to enabler.
2202 */
2203 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2204 if (!enabler_ref)
2205 return -ENOMEM;
2206
2207 enabler_ref->ref = event_enabler;
2208 list_add(&enabler_ref->node, &event_priv->enablers_ref_head);
2209 }
2210
2211 lttng_event_enabler_init_event_filter(event_enabler, event);
2212 lttng_event_enabler_init_event_capture(event_enabler, event);
2213 }
2214 return 0;
2215 }
2216
2217 /*
2218 * Called at module load: connect the probe on all enablers matching
2219 * this event.
2220 * Called with sessions lock held.
2221 */
2222 int lttng_fix_pending_events(void)
2223 {
2224 struct lttng_kernel_session_private *session_priv;
2225
2226 list_for_each_entry(session_priv, &sessions, list)
2227 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2228 return 0;
2229 }
2230
2231 static bool lttng_event_notifier_group_has_active_event_notifiers(
2232 struct lttng_event_notifier_group *event_notifier_group)
2233 {
2234 struct lttng_event_enabler_common *event_enabler;
2235
2236 list_for_each_entry(event_enabler, &event_notifier_group->enablers_head, node) {
2237 if (event_enabler->enabled)
2238 return true;
2239 }
2240 return false;
2241 }
2242
2243 bool lttng_event_notifier_active(void)
2244 {
2245 struct lttng_event_notifier_group *event_notifier_group;
2246
2247 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2248 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2249 return true;
2250 }
2251 return false;
2252 }
2253
2254 int lttng_fix_pending_event_notifiers(void)
2255 {
2256 struct lttng_event_notifier_group *event_notifier_group;
2257
2258 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2259 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2260 return 0;
2261 }
2262
2263 struct lttng_event_recorder_enabler *lttng_event_recorder_enabler_create(
2264 enum lttng_enabler_format_type format_type,
2265 struct lttng_kernel_abi_event *event_param,
2266 struct lttng_kernel_channel_buffer *chan)
2267 {
2268 struct lttng_event_recorder_enabler *event_enabler;
2269
2270 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2271 if (!event_enabler)
2272 return NULL;
2273 event_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_RECORDER;
2274 event_enabler->parent.format_type = format_type;
2275 INIT_LIST_HEAD(&event_enabler->parent.filter_bytecode_head);
2276 memcpy(&event_enabler->parent.event_param, event_param,
2277 sizeof(event_enabler->parent.event_param));
2278 event_enabler->chan = chan;
2279 /* ctx left NULL */
2280 event_enabler->parent.enabled = 0;
2281 return event_enabler;
2282 }
2283
2284 void lttng_event_enabler_session_add(struct lttng_kernel_session *session,
2285 struct lttng_event_recorder_enabler *event_enabler)
2286 {
2287 mutex_lock(&sessions_mutex);
2288 list_add(&event_enabler->parent.node, &session->priv->enablers_head);
2289 event_enabler->parent.published = true;
2290 lttng_session_lazy_sync_event_enablers(session);
2291 mutex_unlock(&sessions_mutex);
2292 }
2293
2294 int lttng_event_enabler_enable(struct lttng_event_enabler_common *event_enabler)
2295 {
2296 mutex_lock(&sessions_mutex);
2297 event_enabler->enabled = 1;
2298 lttng_event_enabler_sync(event_enabler);
2299 mutex_unlock(&sessions_mutex);
2300 return 0;
2301 }
2302
2303 int lttng_event_enabler_disable(struct lttng_event_enabler_common *event_enabler)
2304 {
2305 mutex_lock(&sessions_mutex);
2306 event_enabler->enabled = 0;
2307 lttng_event_enabler_sync(event_enabler);
2308 mutex_unlock(&sessions_mutex);
2309 return 0;
2310 }
2311
2312 static
2313 int lttng_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *enabler,
2314 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2315 {
2316 struct lttng_kernel_bytecode_node *bytecode_node;
2317 uint32_t bytecode_len;
2318 int ret;
2319
2320 ret = get_user(bytecode_len, &bytecode->len);
2321 if (ret)
2322 return ret;
2323 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2324 GFP_KERNEL);
2325 if (!bytecode_node)
2326 return -ENOMEM;
2327 ret = copy_from_user(&bytecode_node->bc, bytecode,
2328 sizeof(*bytecode) + bytecode_len);
2329 if (ret)
2330 goto error_free;
2331
2332 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2333 bytecode_node->enabler = enabler;
2334 /* Enforce length based on allocated size */
2335 bytecode_node->bc.len = bytecode_len;
2336 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2337
2338 return 0;
2339
2340 error_free:
2341 lttng_kvfree(bytecode_node);
2342 return ret;
2343 }
2344
2345 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *event_enabler,
2346 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2347 {
2348 int ret;
2349 ret = lttng_enabler_attach_filter_bytecode(event_enabler, bytecode);
2350 if (ret)
2351 goto error;
2352 lttng_event_enabler_sync(event_enabler);
2353 return 0;
2354
2355 error:
2356 return ret;
2357 }
2358
2359 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2360 struct lttng_kernel_abi_event_callsite __user *callsite)
2361 {
2362
2363 switch (event->priv->instrumentation) {
2364 case LTTNG_KERNEL_ABI_UPROBE:
2365 return lttng_uprobes_event_add_callsite(event, callsite);
2366 default:
2367 return -EINVAL;
2368 }
2369 }
2370
2371 static
2372 void lttng_enabler_destroy(struct lttng_event_enabler_common *enabler)
2373 {
2374 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2375
2376 /* Destroy filter bytecode */
2377 list_for_each_entry_safe(filter_node, tmp_filter_node,
2378 &enabler->filter_bytecode_head, node) {
2379 lttng_kvfree(filter_node);
2380 }
2381 }
2382
2383 void lttng_event_enabler_destroy(struct lttng_event_enabler_common *event_enabler)
2384 {
2385 lttng_enabler_destroy(event_enabler);
2386 if (event_enabler->published)
2387 list_del(&event_enabler->node);
2388
2389 switch (event_enabler->enabler_type) {
2390 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2391 {
2392 struct lttng_event_recorder_enabler *event_recorder_enabler =
2393 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2394
2395 kfree(event_recorder_enabler);
2396 break;
2397 }
2398 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2399 {
2400 struct lttng_event_notifier_enabler *event_notifier_enabler =
2401 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2402
2403 kfree(event_notifier_enabler);
2404 break;
2405 }
2406 default:
2407 WARN_ON_ONCE(1);
2408 }
2409 }
2410
2411 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2412 enum lttng_enabler_format_type format_type,
2413 struct lttng_kernel_abi_event_notifier *event_notifier_param,
2414 struct lttng_event_notifier_group *event_notifier_group)
2415 {
2416 struct lttng_event_notifier_enabler *event_notifier_enabler;
2417
2418 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2419 if (!event_notifier_enabler)
2420 return NULL;
2421
2422 event_notifier_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_NOTIFIER;
2423 event_notifier_enabler->parent.format_type = format_type;
2424 INIT_LIST_HEAD(&event_notifier_enabler->parent.filter_bytecode_head);
2425 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2426
2427 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2428 event_notifier_enabler->num_captures = 0;
2429
2430 memcpy(&event_notifier_enabler->parent.event_param, &event_notifier_param->event,
2431 sizeof(event_notifier_enabler->parent.event_param));
2432
2433 event_notifier_enabler->parent.enabled = 0;
2434 event_notifier_enabler->parent.user_token = event_notifier_param->event.token;
2435 event_notifier_enabler->group = event_notifier_group;
2436 return event_notifier_enabler;
2437 }
2438
2439 void lttng_event_notifier_enabler_group_add(struct lttng_event_notifier_group *event_notifier_group,
2440 struct lttng_event_notifier_enabler *event_notifier_enabler)
2441 {
2442 mutex_lock(&sessions_mutex);
2443 list_add(&event_notifier_enabler->parent.node, &event_notifier_enabler->group->enablers_head);
2444 event_notifier_enabler->parent.published = true;
2445 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2446 mutex_unlock(&sessions_mutex);
2447 }
2448
2449 int lttng_event_notifier_enabler_enable(
2450 struct lttng_event_notifier_enabler *event_notifier_enabler)
2451 {
2452 mutex_lock(&sessions_mutex);
2453 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2454 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2455 mutex_unlock(&sessions_mutex);
2456 return 0;
2457 }
2458
2459 int lttng_event_notifier_enabler_disable(
2460 struct lttng_event_notifier_enabler *event_notifier_enabler)
2461 {
2462 mutex_lock(&sessions_mutex);
2463 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2464 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2465 mutex_unlock(&sessions_mutex);
2466 return 0;
2467 }
2468
2469 int lttng_event_notifier_enabler_attach_capture_bytecode(
2470 struct lttng_event_notifier_enabler *event_notifier_enabler,
2471 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2472 {
2473 struct lttng_kernel_bytecode_node *bytecode_node;
2474 struct lttng_event_enabler_common *enabler =
2475 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2476 uint32_t bytecode_len;
2477 int ret;
2478
2479 ret = get_user(bytecode_len, &bytecode->len);
2480 if (ret)
2481 return ret;
2482
2483 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2484 GFP_KERNEL);
2485 if (!bytecode_node)
2486 return -ENOMEM;
2487
2488 ret = copy_from_user(&bytecode_node->bc, bytecode,
2489 sizeof(*bytecode) + bytecode_len);
2490 if (ret)
2491 goto error_free;
2492
2493 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2494 bytecode_node->enabler = enabler;
2495
2496 /* Enforce length based on allocated size */
2497 bytecode_node->bc.len = bytecode_len;
2498 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2499
2500 event_notifier_enabler->num_captures++;
2501
2502 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2503 goto end;
2504
2505 error_free:
2506 lttng_kvfree(bytecode_node);
2507 end:
2508 return ret;
2509 }
2510
2511 static
2512 void lttng_event_sync_filter_state(struct lttng_kernel_event_common *event)
2513 {
2514 int has_enablers_without_filter_bytecode = 0, nr_filters = 0;
2515 struct lttng_kernel_bytecode_runtime *runtime;
2516 struct lttng_enabler_ref *enabler_ref;
2517
2518 /* Check if has enablers without bytecode enabled */
2519 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2520 if (enabler_ref->ref->enabled
2521 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2522 has_enablers_without_filter_bytecode = 1;
2523 break;
2524 }
2525 }
2526 event->priv->has_enablers_without_filter_bytecode = has_enablers_without_filter_bytecode;
2527
2528 /* Enable filters */
2529 list_for_each_entry(runtime, &event->priv->filter_bytecode_runtime_head, node) {
2530 lttng_bytecode_sync_state(runtime);
2531 nr_filters++;
2532 }
2533 WRITE_ONCE(event->eval_filter, !(has_enablers_without_filter_bytecode || !nr_filters));
2534 }
2535
2536 static
2537 void lttng_event_sync_capture_state(struct lttng_kernel_event_common *event)
2538 {
2539 switch (event->type) {
2540 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2541 break;
2542 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2543 {
2544 struct lttng_kernel_event_notifier *event_notifier =
2545 container_of(event, struct lttng_kernel_event_notifier, parent);
2546 struct lttng_kernel_bytecode_runtime *runtime;
2547 int nr_captures = 0;
2548
2549 /* Enable captures */
2550 list_for_each_entry(runtime, &event_notifier->priv->capture_bytecode_runtime_head, node) {
2551 lttng_bytecode_sync_state(runtime);
2552 nr_captures++;
2553 }
2554 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2555 break;
2556 }
2557 default:
2558 WARN_ON_ONCE(1);
2559 }
2560 }
2561
2562 static
2563 bool lttng_get_event_enabled_state(struct lttng_kernel_event_common *event)
2564 {
2565 struct lttng_enabler_ref *enabler_ref;
2566 bool enabled = false;
2567
2568 switch (event->priv->instrumentation) {
2569 case LTTNG_KERNEL_ABI_TRACEPOINT:
2570 lttng_fallthrough;
2571 case LTTNG_KERNEL_ABI_SYSCALL:
2572 /* Enable events */
2573 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2574 if (enabler_ref->ref->enabled) {
2575 enabled = true;
2576 break;
2577 }
2578 }
2579 break;
2580 default:
2581 WARN_ON_ONCE(1);
2582 return false;
2583 }
2584
2585 switch (event->type) {
2586 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2587 {
2588 struct lttng_kernel_event_recorder *event_recorder =
2589 container_of(event, struct lttng_kernel_event_recorder, parent);
2590
2591 /*
2592 * Enabled state is based on union of enablers, with
2593 * intersection of session and channel transient enable
2594 * states.
2595 */
2596 return enabled && event_recorder->chan->parent.session->priv->tstate && event_recorder->chan->priv->parent.tstate;
2597 }
2598 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2599 return enabled;
2600 default:
2601 WARN_ON_ONCE(1);
2602 return false;
2603 }
2604 }
2605
2606 static
2607 bool lttng_event_is_lazy_sync(struct lttng_kernel_event_common *event)
2608 {
2609 switch (event->priv->instrumentation) {
2610 case LTTNG_KERNEL_ABI_TRACEPOINT:
2611 lttng_fallthrough;
2612 case LTTNG_KERNEL_ABI_SYSCALL:
2613 return true;
2614
2615 default:
2616 /* Not handled with lazy sync. */
2617 return false;
2618 }
2619 }
2620
2621 /*
2622 * Should be called with sessions mutex held.
2623 */
2624 static
2625 void lttng_sync_event_list(struct list_head *event_enabler_list,
2626 struct list_head *event_list)
2627 {
2628 struct lttng_kernel_event_common_private *event_priv;
2629 struct lttng_event_enabler_common *event_enabler;
2630
2631 list_for_each_entry(event_enabler, event_enabler_list, node)
2632 lttng_event_enabler_ref_events(event_enabler);
2633
2634 /*
2635 * For each event, if at least one of its enablers is enabled,
2636 * and its channel and session transient states are enabled, we
2637 * enable the event, else we disable it.
2638 */
2639 list_for_each_entry(event_priv, event_list, node) {
2640 struct lttng_kernel_event_common *event = event_priv->pub;
2641 bool enabled;
2642
2643 if (!lttng_event_is_lazy_sync(event))
2644 continue;
2645
2646 enabled = lttng_get_event_enabled_state(event);
2647 WRITE_ONCE(event->enabled, enabled);
2648 /*
2649 * Sync tracepoint registration with event enabled state.
2650 */
2651 if (enabled) {
2652 if (!event_priv->registered)
2653 register_event(event);
2654 } else {
2655 if (event_priv->registered)
2656 unregister_event(event);
2657 }
2658
2659 lttng_event_sync_filter_state(event);
2660 lttng_event_sync_capture_state(event);
2661 }
2662 }
2663
2664 /*
2665 * lttng_session_sync_event_enablers should be called just before starting a
2666 * session.
2667 */
2668 static
2669 void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2670 {
2671 lttng_sync_event_list(&session->priv->enablers_head, &session->priv->events);
2672 }
2673
2674 /*
2675 * Apply enablers to session events, adding events to session if need
2676 * be. It is required after each modification applied to an active
2677 * session, and right before session "start".
2678 * "lazy" sync means we only sync if required.
2679 * Should be called with sessions mutex held.
2680 */
2681 static
2682 void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2683 {
2684 /* We can skip if session is not active */
2685 if (!session->active)
2686 return;
2687 lttng_session_sync_event_enablers(session);
2688 }
2689
2690 static
2691 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2692 {
2693 lttng_sync_event_list(&event_notifier_group->enablers_head, &event_notifier_group->event_notifiers_head);
2694 }
2695
2696 static
2697 void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler)
2698 {
2699 switch (event_enabler->enabler_type) {
2700 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2701 {
2702 struct lttng_event_recorder_enabler *event_recorder_enabler =
2703 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2704 lttng_session_lazy_sync_event_enablers(event_recorder_enabler->chan->parent.session);
2705 break;
2706 }
2707 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2708 {
2709 struct lttng_event_notifier_enabler *event_notifier_enabler =
2710 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2711 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2712 break;
2713 }
2714 default:
2715 WARN_ON_ONCE(1);
2716 }
2717 }
2718
2719 /*
2720 * Serialize at most one packet worth of metadata into a metadata
2721 * channel.
2722 * We grab the metadata cache mutex to get exclusive access to our metadata
2723 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2724 * allows us to do racy operations such as looking for remaining space left in
2725 * packet and write, since mutual exclusion protects us from concurrent writes.
2726 * Mutual exclusion on the metadata cache allow us to read the cache content
2727 * without racing against reallocation of the cache by updates.
2728 * Returns the number of bytes written in the channel, 0 if no data
2729 * was written and a negative value on error.
2730 */
2731 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2732 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2733 {
2734 struct lttng_kernel_ring_buffer_ctx ctx;
2735 int ret = 0;
2736 size_t len, reserve_len;
2737
2738 /*
2739 * Ensure we support mutiple get_next / put sequences followed by
2740 * put_next. The metadata cache lock protects reading the metadata
2741 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2742 * "flush" operations on the buffer invoked by different processes.
2743 * Moreover, since the metadata cache memory can be reallocated, we
2744 * need to have exclusive access against updates even though we only
2745 * read it.
2746 */
2747 mutex_lock(&stream->metadata_cache->lock);
2748 WARN_ON(stream->metadata_in < stream->metadata_out);
2749 if (stream->metadata_in != stream->metadata_out)
2750 goto end;
2751
2752 /* Metadata regenerated, change the version. */
2753 if (stream->metadata_cache->version != stream->version)
2754 stream->version = stream->metadata_cache->version;
2755
2756 len = stream->metadata_cache->metadata_written -
2757 stream->metadata_in;
2758 if (!len)
2759 goto end;
2760 reserve_len = min_t(size_t,
2761 stream->transport->ops.priv->packet_avail_size(chan),
2762 len);
2763 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2764 sizeof(char), NULL);
2765 /*
2766 * If reservation failed, return an error to the caller.
2767 */
2768 ret = stream->transport->ops.event_reserve(&ctx);
2769 if (ret != 0) {
2770 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2771 stream->coherent = false;
2772 goto end;
2773 }
2774 stream->transport->ops.event_write(&ctx,
2775 stream->metadata_cache->data + stream->metadata_in,
2776 reserve_len, 1);
2777 stream->transport->ops.event_commit(&ctx);
2778 stream->metadata_in += reserve_len;
2779 if (reserve_len < len)
2780 stream->coherent = false;
2781 else
2782 stream->coherent = true;
2783 ret = reserve_len;
2784
2785 end:
2786 if (coherent)
2787 *coherent = stream->coherent;
2788 mutex_unlock(&stream->metadata_cache->lock);
2789 return ret;
2790 }
2791
2792 static
2793 void lttng_metadata_begin(struct lttng_kernel_session *session)
2794 {
2795 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
2796 mutex_lock(&session->priv->metadata_cache->lock);
2797 }
2798
2799 static
2800 void lttng_metadata_end(struct lttng_kernel_session *session)
2801 {
2802 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2803 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
2804 struct lttng_metadata_stream *stream;
2805
2806 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
2807 wake_up_interruptible(&stream->read_wait);
2808 mutex_unlock(&session->priv->metadata_cache->lock);
2809 }
2810 }
2811
2812 /*
2813 * Write the metadata to the metadata cache.
2814 * Must be called with sessions_mutex held.
2815 * The metadata cache lock protects us from concurrent read access from
2816 * thread outputting metadata content to ring buffer.
2817 * The content of the printf is printed as a single atomic metadata
2818 * transaction.
2819 */
2820 int lttng_metadata_printf(struct lttng_kernel_session *session,
2821 const char *fmt, ...)
2822 {
2823 char *str;
2824 size_t len;
2825 va_list ap;
2826
2827 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2828
2829 va_start(ap, fmt);
2830 str = kvasprintf(GFP_KERNEL, fmt, ap);
2831 va_end(ap);
2832 if (!str)
2833 return -ENOMEM;
2834
2835 len = strlen(str);
2836 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2837 if (session->priv->metadata_cache->metadata_written + len >
2838 session->priv->metadata_cache->cache_alloc) {
2839 char *tmp_cache_realloc;
2840 unsigned int tmp_cache_alloc_size;
2841
2842 tmp_cache_alloc_size = max_t(unsigned int,
2843 session->priv->metadata_cache->cache_alloc + len,
2844 session->priv->metadata_cache->cache_alloc << 1);
2845 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2846 if (!tmp_cache_realloc)
2847 goto err;
2848 if (session->priv->metadata_cache->data) {
2849 memcpy(tmp_cache_realloc,
2850 session->priv->metadata_cache->data,
2851 session->priv->metadata_cache->cache_alloc);
2852 vfree(session->priv->metadata_cache->data);
2853 }
2854
2855 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2856 session->priv->metadata_cache->data = tmp_cache_realloc;
2857 }
2858 memcpy(session->priv->metadata_cache->data +
2859 session->priv->metadata_cache->metadata_written,
2860 str, len);
2861 session->priv->metadata_cache->metadata_written += len;
2862 kfree(str);
2863
2864 return 0;
2865
2866 err:
2867 kfree(str);
2868 return -ENOMEM;
2869 }
2870
2871 static
2872 int print_tabs(struct lttng_kernel_session *session, size_t nesting)
2873 {
2874 size_t i;
2875
2876 for (i = 0; i < nesting; i++) {
2877 int ret;
2878
2879 ret = lttng_metadata_printf(session, " ");
2880 if (ret) {
2881 return ret;
2882 }
2883 }
2884 return 0;
2885 }
2886
2887 static
2888 int lttng_field_name_statedump(struct lttng_kernel_session *session,
2889 const struct lttng_kernel_event_field *field,
2890 size_t nesting)
2891 {
2892 return lttng_metadata_printf(session, " _%s;\n", field->name);
2893 }
2894
2895 static
2896 int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
2897 const struct lttng_kernel_type_integer *type,
2898 enum lttng_kernel_string_encoding parent_encoding,
2899 size_t nesting)
2900 {
2901 int ret;
2902
2903 ret = print_tabs(session, nesting);
2904 if (ret)
2905 return ret;
2906 ret = lttng_metadata_printf(session,
2907 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
2908 type->size,
2909 type->alignment,
2910 type->signedness,
2911 (parent_encoding == lttng_kernel_string_encoding_none)
2912 ? "none"
2913 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
2914 ? "UTF8"
2915 : "ASCII",
2916 type->base,
2917 #if __BYTE_ORDER == __BIG_ENDIAN
2918 type->reverse_byte_order ? " byte_order = le;" : ""
2919 #else
2920 type->reverse_byte_order ? " byte_order = be;" : ""
2921 #endif
2922 );
2923 return ret;
2924 }
2925
2926 /*
2927 * Must be called with sessions_mutex held.
2928 */
2929 static
2930 int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
2931 const struct lttng_kernel_type_struct *type,
2932 size_t nesting)
2933 {
2934 const char *prev_field_name = NULL;
2935 int ret;
2936 uint32_t i, nr_fields;
2937 unsigned int alignment;
2938
2939 ret = print_tabs(session, nesting);
2940 if (ret)
2941 return ret;
2942 ret = lttng_metadata_printf(session,
2943 "struct {\n");
2944 if (ret)
2945 return ret;
2946 nr_fields = type->nr_fields;
2947 for (i = 0; i < nr_fields; i++) {
2948 const struct lttng_kernel_event_field *iter_field;
2949
2950 iter_field = type->fields[i];
2951 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
2952 if (ret)
2953 return ret;
2954 }
2955 ret = print_tabs(session, nesting);
2956 if (ret)
2957 return ret;
2958 alignment = type->alignment;
2959 if (alignment) {
2960 ret = lttng_metadata_printf(session,
2961 "} align(%u)",
2962 alignment);
2963 } else {
2964 ret = lttng_metadata_printf(session,
2965 "}");
2966 }
2967 return ret;
2968 }
2969
2970 /*
2971 * Must be called with sessions_mutex held.
2972 */
2973 static
2974 int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
2975 const struct lttng_kernel_event_field *field,
2976 size_t nesting)
2977 {
2978 int ret;
2979
2980 ret = _lttng_struct_type_statedump(session,
2981 lttng_kernel_get_type_struct(field->type), nesting);
2982 if (ret)
2983 return ret;
2984 return lttng_field_name_statedump(session, field, nesting);
2985 }
2986
2987 /*
2988 * Must be called with sessions_mutex held.
2989 */
2990 static
2991 int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
2992 const struct lttng_kernel_type_variant *type,
2993 size_t nesting,
2994 const char *prev_field_name)
2995 {
2996 const char *tag_name;
2997 int ret;
2998 uint32_t i, nr_choices;
2999
3000 tag_name = type->tag_name;
3001 if (!tag_name)
3002 tag_name = prev_field_name;
3003 if (!tag_name)
3004 return -EINVAL;
3005 /*
3006 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3007 */
3008 if (type->alignment != 0)
3009 return -EINVAL;
3010 ret = print_tabs(session, nesting);
3011 if (ret)
3012 return ret;
3013 ret = lttng_metadata_printf(session,
3014 "variant <_%s> {\n",
3015 tag_name);
3016 if (ret)
3017 return ret;
3018 nr_choices = type->nr_choices;
3019 for (i = 0; i < nr_choices; i++) {
3020 const struct lttng_kernel_event_field *iter_field;
3021
3022 iter_field = type->choices[i];
3023 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3024 if (ret)
3025 return ret;
3026 }
3027 ret = print_tabs(session, nesting);
3028 if (ret)
3029 return ret;
3030 ret = lttng_metadata_printf(session,
3031 "}");
3032 return ret;
3033 }
3034
3035 /*
3036 * Must be called with sessions_mutex held.
3037 */
3038 static
3039 int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3040 const struct lttng_kernel_event_field *field,
3041 size_t nesting,
3042 const char *prev_field_name)
3043 {
3044 int ret;
3045
3046 ret = _lttng_variant_type_statedump(session,
3047 lttng_kernel_get_type_variant(field->type), nesting,
3048 prev_field_name);
3049 if (ret)
3050 return ret;
3051 return lttng_field_name_statedump(session, field, nesting);
3052 }
3053
3054 /*
3055 * Must be called with sessions_mutex held.
3056 */
3057 static
3058 int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3059 const struct lttng_kernel_event_field *field,
3060 size_t nesting)
3061 {
3062 int ret;
3063 const struct lttng_kernel_type_array *array_type;
3064 const struct lttng_kernel_type_common *elem_type;
3065
3066 array_type = lttng_kernel_get_type_array(field->type);
3067 WARN_ON_ONCE(!array_type);
3068
3069 if (array_type->alignment) {
3070 ret = print_tabs(session, nesting);
3071 if (ret)
3072 return ret;
3073 ret = lttng_metadata_printf(session,
3074 "struct { } align(%u) _%s_padding;\n",
3075 array_type->alignment * CHAR_BIT,
3076 field->name);
3077 if (ret)
3078 return ret;
3079 }
3080 /*
3081 * Nested compound types: Only array of structures and variants are
3082 * currently supported.
3083 */
3084 elem_type = array_type->elem_type;
3085 switch (elem_type->type) {
3086 case lttng_kernel_type_integer:
3087 case lttng_kernel_type_struct:
3088 case lttng_kernel_type_variant:
3089 ret = _lttng_type_statedump(session, elem_type,
3090 array_type->encoding, nesting);
3091 if (ret)
3092 return ret;
3093 break;
3094
3095 default:
3096 return -EINVAL;
3097 }
3098 ret = lttng_metadata_printf(session,
3099 " _%s[%u];\n",
3100 field->name,
3101 array_type->length);
3102 return ret;
3103 }
3104
3105 /*
3106 * Must be called with sessions_mutex held.
3107 */
3108 static
3109 int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3110 const struct lttng_kernel_event_field *field,
3111 size_t nesting,
3112 const char *prev_field_name)
3113 {
3114 int ret;
3115 const char *length_name;
3116 const struct lttng_kernel_type_sequence *sequence_type;
3117 const struct lttng_kernel_type_common *elem_type;
3118
3119 sequence_type = lttng_kernel_get_type_sequence(field->type);
3120 WARN_ON_ONCE(!sequence_type);
3121
3122 length_name = sequence_type->length_name;
3123 if (!length_name)
3124 length_name = prev_field_name;
3125 if (!length_name)
3126 return -EINVAL;
3127
3128 if (sequence_type->alignment) {
3129 ret = print_tabs(session, nesting);
3130 if (ret)
3131 return ret;
3132 ret = lttng_metadata_printf(session,
3133 "struct { } align(%u) _%s_padding;\n",
3134 sequence_type->alignment * CHAR_BIT,
3135 field->name);
3136 if (ret)
3137 return ret;
3138 }
3139
3140 /*
3141 * Nested compound types: Only array of structures and variants are
3142 * currently supported.
3143 */
3144 elem_type = sequence_type->elem_type;
3145 switch (elem_type->type) {
3146 case lttng_kernel_type_integer:
3147 case lttng_kernel_type_struct:
3148 case lttng_kernel_type_variant:
3149 ret = _lttng_type_statedump(session, elem_type,
3150 sequence_type->encoding, nesting);
3151 if (ret)
3152 return ret;
3153 break;
3154
3155 default:
3156 return -EINVAL;
3157 }
3158 ret = lttng_metadata_printf(session,
3159 " _%s[ _%s ];\n",
3160 field->name,
3161 length_name);
3162 return ret;
3163 }
3164
3165 /*
3166 * Must be called with sessions_mutex held.
3167 */
3168 static
3169 int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3170 const struct lttng_kernel_type_enum *type,
3171 size_t nesting)
3172 {
3173 const struct lttng_kernel_enum_desc *enum_desc;
3174 const struct lttng_kernel_type_common *container_type;
3175 int ret;
3176 unsigned int i, nr_entries;
3177
3178 container_type = type->container_type;
3179 if (container_type->type != lttng_kernel_type_integer) {
3180 ret = -EINVAL;
3181 goto end;
3182 }
3183 enum_desc = type->desc;
3184 nr_entries = enum_desc->nr_entries;
3185
3186 ret = print_tabs(session, nesting);
3187 if (ret)
3188 goto end;
3189 ret = lttng_metadata_printf(session, "enum : ");
3190 if (ret)
3191 goto end;
3192 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3193 lttng_kernel_string_encoding_none, 0);
3194 if (ret)
3195 goto end;
3196 ret = lttng_metadata_printf(session, " {\n");
3197 if (ret)
3198 goto end;
3199 /* Dump all entries */
3200 for (i = 0; i < nr_entries; i++) {
3201 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3202 int j, len;
3203
3204 ret = print_tabs(session, nesting + 1);
3205 if (ret)
3206 goto end;
3207 ret = lttng_metadata_printf(session,
3208 "\"");
3209 if (ret)
3210 goto end;
3211 len = strlen(entry->string);
3212 /* Escape the character '"' */
3213 for (j = 0; j < len; j++) {
3214 char c = entry->string[j];
3215
3216 switch (c) {
3217 case '"':
3218 ret = lttng_metadata_printf(session,
3219 "\\\"");
3220 break;
3221 case '\\':
3222 ret = lttng_metadata_printf(session,
3223 "\\\\");
3224 break;
3225 default:
3226 ret = lttng_metadata_printf(session,
3227 "%c", c);
3228 break;
3229 }
3230 if (ret)
3231 goto end;
3232 }
3233 ret = lttng_metadata_printf(session, "\"");
3234 if (ret)
3235 goto end;
3236
3237 if (entry->options.is_auto) {
3238 ret = lttng_metadata_printf(session, ",\n");
3239 if (ret)
3240 goto end;
3241 } else {
3242 ret = lttng_metadata_printf(session,
3243 " = ");
3244 if (ret)
3245 goto end;
3246 if (entry->start.signedness)
3247 ret = lttng_metadata_printf(session,
3248 "%lld", (long long) entry->start.value);
3249 else
3250 ret = lttng_metadata_printf(session,
3251 "%llu", entry->start.value);
3252 if (ret)
3253 goto end;
3254 if (entry->start.signedness == entry->end.signedness &&
3255 entry->start.value
3256 == entry->end.value) {
3257 ret = lttng_metadata_printf(session,
3258 ",\n");
3259 } else {
3260 if (entry->end.signedness) {
3261 ret = lttng_metadata_printf(session,
3262 " ... %lld,\n",
3263 (long long) entry->end.value);
3264 } else {
3265 ret = lttng_metadata_printf(session,
3266 " ... %llu,\n",
3267 entry->end.value);
3268 }
3269 }
3270 if (ret)
3271 goto end;
3272 }
3273 }
3274 ret = print_tabs(session, nesting);
3275 if (ret)
3276 goto end;
3277 ret = lttng_metadata_printf(session, "}");
3278 end:
3279 return ret;
3280 }
3281
3282 /*
3283 * Must be called with sessions_mutex held.
3284 */
3285 static
3286 int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3287 const struct lttng_kernel_event_field *field,
3288 size_t nesting)
3289 {
3290 int ret;
3291 const struct lttng_kernel_type_enum *enum_type;
3292
3293 enum_type = lttng_kernel_get_type_enum(field->type);
3294 WARN_ON_ONCE(!enum_type);
3295 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3296 if (ret)
3297 return ret;
3298 return lttng_field_name_statedump(session, field, nesting);
3299 }
3300
3301 static
3302 int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3303 const struct lttng_kernel_event_field *field,
3304 size_t nesting)
3305 {
3306 int ret;
3307
3308 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3309 lttng_kernel_string_encoding_none, nesting);
3310 if (ret)
3311 return ret;
3312 return lttng_field_name_statedump(session, field, nesting);
3313 }
3314
3315 static
3316 int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3317 const struct lttng_kernel_type_string *type,
3318 size_t nesting)
3319 {
3320 int ret;
3321
3322 /* Default encoding is UTF8 */
3323 ret = print_tabs(session, nesting);
3324 if (ret)
3325 return ret;
3326 ret = lttng_metadata_printf(session,
3327 "string%s",
3328 type->encoding == lttng_kernel_string_encoding_ASCII ?
3329 " { encoding = ASCII; }" : "");
3330 return ret;
3331 }
3332
3333 static
3334 int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3335 const struct lttng_kernel_event_field *field,
3336 size_t nesting)
3337 {
3338 const struct lttng_kernel_type_string *string_type;
3339 int ret;
3340
3341 string_type = lttng_kernel_get_type_string(field->type);
3342 WARN_ON_ONCE(!string_type);
3343 ret = _lttng_string_type_statedump(session, string_type, nesting);
3344 if (ret)
3345 return ret;
3346 return lttng_field_name_statedump(session, field, nesting);
3347 }
3348
3349 /*
3350 * Must be called with sessions_mutex held.
3351 */
3352 static
3353 int _lttng_type_statedump(struct lttng_kernel_session *session,
3354 const struct lttng_kernel_type_common *type,
3355 enum lttng_kernel_string_encoding parent_encoding,
3356 size_t nesting)
3357 {
3358 int ret = 0;
3359
3360 switch (type->type) {
3361 case lttng_kernel_type_integer:
3362 ret = _lttng_integer_type_statedump(session,
3363 lttng_kernel_get_type_integer(type),
3364 parent_encoding, nesting);
3365 break;
3366 case lttng_kernel_type_enum:
3367 ret = _lttng_enum_type_statedump(session,
3368 lttng_kernel_get_type_enum(type),
3369 nesting);
3370 break;
3371 case lttng_kernel_type_string:
3372 ret = _lttng_string_type_statedump(session,
3373 lttng_kernel_get_type_string(type),
3374 nesting);
3375 break;
3376 case lttng_kernel_type_struct:
3377 ret = _lttng_struct_type_statedump(session,
3378 lttng_kernel_get_type_struct(type),
3379 nesting);
3380 break;
3381 case lttng_kernel_type_variant:
3382 ret = _lttng_variant_type_statedump(session,
3383 lttng_kernel_get_type_variant(type),
3384 nesting, NULL);
3385 break;
3386
3387 /* Nested arrays and sequences are not supported yet. */
3388 case lttng_kernel_type_array:
3389 case lttng_kernel_type_sequence:
3390 default:
3391 WARN_ON_ONCE(1);
3392 return -EINVAL;
3393 }
3394 return ret;
3395 }
3396
3397 /*
3398 * Must be called with sessions_mutex held.
3399 */
3400 static
3401 int _lttng_field_statedump(struct lttng_kernel_session *session,
3402 const struct lttng_kernel_event_field *field,
3403 size_t nesting,
3404 const char **prev_field_name_p)
3405 {
3406 const char *prev_field_name = NULL;
3407 int ret = 0;
3408
3409 if (prev_field_name_p)
3410 prev_field_name = *prev_field_name_p;
3411 switch (field->type->type) {
3412 case lttng_kernel_type_integer:
3413 ret = _lttng_integer_field_statedump(session, field, nesting);
3414 break;
3415 case lttng_kernel_type_enum:
3416 ret = _lttng_enum_field_statedump(session, field, nesting);
3417 break;
3418 case lttng_kernel_type_string:
3419 ret = _lttng_string_field_statedump(session, field, nesting);
3420 break;
3421 case lttng_kernel_type_struct:
3422 ret = _lttng_struct_field_statedump(session, field, nesting);
3423 break;
3424 case lttng_kernel_type_array:
3425 ret = _lttng_array_field_statedump(session, field, nesting);
3426 break;
3427 case lttng_kernel_type_sequence:
3428 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3429 break;
3430 case lttng_kernel_type_variant:
3431 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3432 break;
3433
3434 default:
3435 WARN_ON_ONCE(1);
3436 return -EINVAL;
3437 }
3438 if (prev_field_name_p)
3439 *prev_field_name_p = field->name;
3440 return ret;
3441 }
3442
3443 static
3444 int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3445 struct lttng_kernel_ctx *ctx)
3446 {
3447 const char *prev_field_name = NULL;
3448 int ret = 0;
3449 int i;
3450
3451 if (!ctx)
3452 return 0;
3453 for (i = 0; i < ctx->nr_fields; i++) {
3454 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3455
3456 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3457 if (ret)
3458 return ret;
3459 }
3460 return ret;
3461 }
3462
3463 static
3464 int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3465 struct lttng_kernel_event_recorder *event_recorder)
3466 {
3467 const char *prev_field_name = NULL;
3468 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3469 int ret = 0;
3470 int i;
3471
3472 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3473 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3474
3475 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3476 if (ret)
3477 return ret;
3478 }
3479 return ret;
3480 }
3481
3482 /*
3483 * Must be called with sessions_mutex held.
3484 * The entire event metadata is printed as a single atomic metadata
3485 * transaction.
3486 */
3487 static
3488 int _lttng_event_recorder_metadata_statedump(struct lttng_kernel_event_common *event)
3489 {
3490 struct lttng_kernel_event_recorder *event_recorder;
3491 struct lttng_kernel_channel_buffer *chan;
3492 struct lttng_kernel_session *session;
3493 int ret = 0;
3494
3495 if (event->type != LTTNG_KERNEL_EVENT_TYPE_RECORDER)
3496 return 0;
3497 event_recorder = container_of(event, struct lttng_kernel_event_recorder, parent);
3498 chan = event_recorder->chan;
3499 session = chan->parent.session;
3500
3501 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3502 return 0;
3503 if (chan->priv->channel_type == METADATA_CHANNEL)
3504 return 0;
3505
3506 lttng_metadata_begin(session);
3507
3508 ret = lttng_metadata_printf(session,
3509 "event {\n"
3510 " name = \"%s\";\n"
3511 " id = %u;\n"
3512 " stream_id = %u;\n",
3513 event_recorder->priv->parent.desc->event_name,
3514 event_recorder->priv->id,
3515 event_recorder->chan->priv->id);
3516 if (ret)
3517 goto end;
3518
3519 ret = lttng_metadata_printf(session,
3520 " fields := struct {\n"
3521 );
3522 if (ret)
3523 goto end;
3524
3525 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3526 if (ret)
3527 goto end;
3528
3529 /*
3530 * LTTng space reservation can only reserve multiples of the
3531 * byte size.
3532 */
3533 ret = lttng_metadata_printf(session,
3534 " };\n"
3535 "};\n\n");
3536 if (ret)
3537 goto end;
3538
3539 event_recorder->priv->metadata_dumped = 1;
3540 end:
3541 lttng_metadata_end(session);
3542 return ret;
3543
3544 }
3545
3546 /*
3547 * Must be called with sessions_mutex held.
3548 * The entire channel metadata is printed as a single atomic metadata
3549 * transaction.
3550 */
3551 static
3552 int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3553 struct lttng_kernel_channel_buffer *chan)
3554 {
3555 int ret = 0;
3556
3557 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3558 return 0;
3559
3560 if (chan->priv->channel_type == METADATA_CHANNEL)
3561 return 0;
3562
3563 lttng_metadata_begin(session);
3564
3565 WARN_ON_ONCE(!chan->priv->header_type);
3566 ret = lttng_metadata_printf(session,
3567 "stream {\n"
3568 " id = %u;\n"
3569 " event.header := %s;\n"
3570 " packet.context := struct packet_context;\n",
3571 chan->priv->id,
3572 chan->priv->header_type == 1 ? "struct event_header_compact" :
3573 "struct event_header_large");
3574 if (ret)
3575 goto end;
3576
3577 if (chan->priv->ctx) {
3578 ret = lttng_metadata_printf(session,
3579 " event.context := struct {\n");
3580 if (ret)
3581 goto end;
3582 }
3583 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3584 if (ret)
3585 goto end;
3586 if (chan->priv->ctx) {
3587 ret = lttng_metadata_printf(session,
3588 " };\n");
3589 if (ret)
3590 goto end;
3591 }
3592
3593 ret = lttng_metadata_printf(session,
3594 "};\n\n");
3595
3596 chan->priv->metadata_dumped = 1;
3597 end:
3598 lttng_metadata_end(session);
3599 return ret;
3600 }
3601
3602 /*
3603 * Must be called with sessions_mutex held.
3604 */
3605 static
3606 int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3607 {
3608 return lttng_metadata_printf(session,
3609 "struct packet_context {\n"
3610 " uint64_clock_monotonic_t timestamp_begin;\n"
3611 " uint64_clock_monotonic_t timestamp_end;\n"
3612 " uint64_t content_size;\n"
3613 " uint64_t packet_size;\n"
3614 " uint64_t packet_seq_num;\n"
3615 " unsigned long events_discarded;\n"
3616 " uint32_t cpu_id;\n"
3617 "};\n\n"
3618 );
3619 }
3620
3621 /*
3622 * Compact header:
3623 * id: range: 0 - 30.
3624 * id 31 is reserved to indicate an extended header.
3625 *
3626 * Large header:
3627 * id: range: 0 - 65534.
3628 * id 65535 is reserved to indicate an extended header.
3629 *
3630 * Must be called with sessions_mutex held.
3631 */
3632 static
3633 int _lttng_event_header_declare(struct lttng_kernel_session *session)
3634 {
3635 return lttng_metadata_printf(session,
3636 "struct event_header_compact {\n"
3637 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3638 " variant <id> {\n"
3639 " struct {\n"
3640 " uint27_clock_monotonic_t timestamp;\n"
3641 " } compact;\n"
3642 " struct {\n"
3643 " uint32_t id;\n"
3644 " uint64_clock_monotonic_t timestamp;\n"
3645 " } extended;\n"
3646 " } v;\n"
3647 "} align(%u);\n"
3648 "\n"
3649 "struct event_header_large {\n"
3650 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3651 " variant <id> {\n"
3652 " struct {\n"
3653 " uint32_clock_monotonic_t timestamp;\n"
3654 " } compact;\n"
3655 " struct {\n"
3656 " uint32_t id;\n"
3657 " uint64_clock_monotonic_t timestamp;\n"
3658 " } extended;\n"
3659 " } v;\n"
3660 "} align(%u);\n\n",
3661 lttng_alignof(uint32_t) * CHAR_BIT,
3662 lttng_alignof(uint16_t) * CHAR_BIT
3663 );
3664 }
3665
3666 /*
3667 * Approximation of NTP time of day to clock monotonic correlation,
3668 * taken at start of trace.
3669 * Yes, this is only an approximation. Yes, we can (and will) do better
3670 * in future versions.
3671 * This function may return a negative offset. It may happen if the
3672 * system sets the REALTIME clock to 0 after boot.
3673 *
3674 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3675 * y2038 compliant.
3676 */
3677 static
3678 int64_t measure_clock_offset(void)
3679 {
3680 uint64_t monotonic_avg, monotonic[2], realtime;
3681 uint64_t tcf = trace_clock_freq();
3682 int64_t offset;
3683 unsigned long flags;
3684 struct timespec64 rts = { 0, 0 };
3685
3686 /* Disable interrupts to increase correlation precision. */
3687 local_irq_save(flags);
3688 monotonic[0] = trace_clock_read64();
3689 ktime_get_real_ts64(&rts);
3690 monotonic[1] = trace_clock_read64();
3691 local_irq_restore(flags);
3692
3693 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3694 realtime = (uint64_t) rts.tv_sec * tcf;
3695 if (tcf == NSEC_PER_SEC) {
3696 realtime += rts.tv_nsec;
3697 } else {
3698 uint64_t n = rts.tv_nsec * tcf;
3699
3700 do_div(n, NSEC_PER_SEC);
3701 realtime += n;
3702 }
3703 offset = (int64_t) realtime - monotonic_avg;
3704 return offset;
3705 }
3706
3707 static
3708 int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3709 {
3710 int ret = 0;
3711 size_t i;
3712 char cur;
3713
3714 i = 0;
3715 cur = string[i];
3716 while (cur != '\0') {
3717 switch (cur) {
3718 case '\n':
3719 ret = lttng_metadata_printf(session, "%s", "\\n");
3720 break;
3721 case '\\':
3722 case '"':
3723 ret = lttng_metadata_printf(session, "%c", '\\');
3724 if (ret)
3725 goto error;
3726 /* We still print the current char */
3727 lttng_fallthrough;
3728 default:
3729 ret = lttng_metadata_printf(session, "%c", cur);
3730 break;
3731 }
3732
3733 if (ret)
3734 goto error;
3735
3736 cur = string[++i];
3737 }
3738 error:
3739 return ret;
3740 }
3741
3742 static
3743 int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3744 const char *field_value)
3745 {
3746 int ret;
3747
3748 ret = lttng_metadata_printf(session, " %s = \"", field);
3749 if (ret)
3750 goto error;
3751
3752 ret = print_escaped_ctf_string(session, field_value);
3753 if (ret)
3754 goto error;
3755
3756 ret = lttng_metadata_printf(session, "\";\n");
3757
3758 error:
3759 return ret;
3760 }
3761
3762 /*
3763 * Output metadata into this session's metadata buffers.
3764 * Must be called with sessions_mutex held.
3765 */
3766 static
3767 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3768 {
3769 unsigned char *uuid_c = session->priv->uuid.b;
3770 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3771 const char *product_uuid;
3772 struct lttng_kernel_channel_buffer_private *chan_priv;
3773 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3774 int ret = 0;
3775
3776 if (!LTTNG_READ_ONCE(session->active))
3777 return 0;
3778
3779 lttng_metadata_begin(session);
3780
3781 if (session->priv->metadata_dumped)
3782 goto skip_session;
3783
3784 snprintf(uuid_s, sizeof(uuid_s),
3785 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3786 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3787 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3788 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3789 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3790
3791 ret = lttng_metadata_printf(session,
3792 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3793 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3794 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3795 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3796 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3797 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3798 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3799 "\n"
3800 "trace {\n"
3801 " major = %u;\n"
3802 " minor = %u;\n"
3803 " uuid = \"%s\";\n"
3804 " byte_order = %s;\n"
3805 " packet.header := struct {\n"
3806 " uint32_t magic;\n"
3807 " uint8_t uuid[16];\n"
3808 " uint32_t stream_id;\n"
3809 " uint64_t stream_instance_id;\n"
3810 " };\n"
3811 "};\n\n",
3812 lttng_alignof(uint8_t) * CHAR_BIT,
3813 lttng_alignof(uint16_t) * CHAR_BIT,
3814 lttng_alignof(uint32_t) * CHAR_BIT,
3815 lttng_alignof(uint64_t) * CHAR_BIT,
3816 sizeof(unsigned long) * CHAR_BIT,
3817 lttng_alignof(unsigned long) * CHAR_BIT,
3818 CTF_SPEC_MAJOR,
3819 CTF_SPEC_MINOR,
3820 uuid_s,
3821 #if __BYTE_ORDER == __BIG_ENDIAN
3822 "be"
3823 #else
3824 "le"
3825 #endif
3826 );
3827 if (ret)
3828 goto end;
3829
3830 ret = lttng_metadata_printf(session,
3831 "env {\n"
3832 " hostname = \"%s\";\n"
3833 " domain = \"kernel\";\n"
3834 " sysname = \"%s\";\n"
3835 " kernel_release = \"%s\";\n"
3836 " kernel_version = \"%s\";\n"
3837 " tracer_name = \"lttng-modules\";\n"
3838 " tracer_major = %d;\n"
3839 " tracer_minor = %d;\n"
3840 " tracer_patchlevel = %d;\n"
3841 " trace_buffering_scheme = \"global\";\n",
3842 current->nsproxy->uts_ns->name.nodename,
3843 utsname()->sysname,
3844 utsname()->release,
3845 utsname()->version,
3846 LTTNG_MODULES_MAJOR_VERSION,
3847 LTTNG_MODULES_MINOR_VERSION,
3848 LTTNG_MODULES_PATCHLEVEL_VERSION
3849 );
3850 if (ret)
3851 goto end;
3852
3853 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
3854 if (ret)
3855 goto end;
3856 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3857 session->priv->creation_time);
3858 if (ret)
3859 goto end;
3860
3861 /* Add the product UUID to the 'env' section */
3862 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3863 if (product_uuid) {
3864 ret = lttng_metadata_printf(session,
3865 " product_uuid = \"%s\";\n",
3866 product_uuid
3867 );
3868 if (ret)
3869 goto end;
3870 }
3871
3872 /* Close the 'env' section */
3873 ret = lttng_metadata_printf(session, "};\n\n");
3874 if (ret)
3875 goto end;
3876
3877 ret = lttng_metadata_printf(session,
3878 "clock {\n"
3879 " name = \"%s\";\n",
3880 trace_clock_name()
3881 );
3882 if (ret)
3883 goto end;
3884
3885 if (!trace_clock_uuid(clock_uuid_s)) {
3886 ret = lttng_metadata_printf(session,
3887 " uuid = \"%s\";\n",
3888 clock_uuid_s
3889 );
3890 if (ret)
3891 goto end;
3892 }
3893
3894 ret = lttng_metadata_printf(session,
3895 " description = \"%s\";\n"
3896 " freq = %llu; /* Frequency, in Hz */\n"
3897 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
3898 " offset = %lld;\n"
3899 "};\n\n",
3900 trace_clock_description(),
3901 (unsigned long long) trace_clock_freq(),
3902 (long long) measure_clock_offset()
3903 );
3904 if (ret)
3905 goto end;
3906
3907 ret = lttng_metadata_printf(session,
3908 "typealias integer {\n"
3909 " size = 27; align = 1; signed = false;\n"
3910 " map = clock.%s.value;\n"
3911 "} := uint27_clock_monotonic_t;\n"
3912 "\n"
3913 "typealias integer {\n"
3914 " size = 32; align = %u; signed = false;\n"
3915 " map = clock.%s.value;\n"
3916 "} := uint32_clock_monotonic_t;\n"
3917 "\n"
3918 "typealias integer {\n"
3919 " size = 64; align = %u; signed = false;\n"
3920 " map = clock.%s.value;\n"
3921 "} := uint64_clock_monotonic_t;\n\n",
3922 trace_clock_name(),
3923 lttng_alignof(uint32_t) * CHAR_BIT,
3924 trace_clock_name(),
3925 lttng_alignof(uint64_t) * CHAR_BIT,
3926 trace_clock_name()
3927 );
3928 if (ret)
3929 goto end;
3930
3931 ret = _lttng_stream_packet_context_declare(session);
3932 if (ret)
3933 goto end;
3934
3935 ret = _lttng_event_header_declare(session);
3936 if (ret)
3937 goto end;
3938
3939 skip_session:
3940 list_for_each_entry(chan_priv, &session->priv->chan, node) {
3941 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
3942 if (ret)
3943 goto end;
3944 }
3945
3946 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
3947 ret = _lttng_event_recorder_metadata_statedump(&event_recorder_priv->pub->parent);
3948 if (ret)
3949 goto end;
3950 }
3951 session->priv->metadata_dumped = 1;
3952 end:
3953 lttng_metadata_end(session);
3954 return ret;
3955 }
3956
3957 /**
3958 * lttng_transport_register - LTT transport registration
3959 * @transport: transport structure
3960 *
3961 * Registers a transport which can be used as output to extract the data out of
3962 * LTTng. The module calling this registration function must ensure that no
3963 * trap-inducing code will be executed by the transport functions. E.g.
3964 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
3965 * is made visible to the transport function. This registration acts as a
3966 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
3967 * after its registration must it synchronize the TLBs.
3968 */
3969 void lttng_transport_register(struct lttng_transport *transport)
3970 {
3971 /*
3972 * Make sure no page fault can be triggered by the module about to be
3973 * registered. We deal with this here so we don't have to call
3974 * vmalloc_sync_mappings() in each module's init.
3975 */
3976 wrapper_vmalloc_sync_mappings();
3977
3978 mutex_lock(&sessions_mutex);
3979 list_add_tail(&transport->node, &lttng_transport_list);
3980 mutex_unlock(&sessions_mutex);
3981 }
3982 EXPORT_SYMBOL_GPL(lttng_transport_register);
3983
3984 /**
3985 * lttng_transport_unregister - LTT transport unregistration
3986 * @transport: transport structure
3987 */
3988 void lttng_transport_unregister(struct lttng_transport *transport)
3989 {
3990 mutex_lock(&sessions_mutex);
3991 list_del(&transport->node);
3992 mutex_unlock(&sessions_mutex);
3993 }
3994 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
3995
3996 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
3997 {
3998 /*
3999 * Make sure no page fault can be triggered by the module about to be
4000 * registered. We deal with this here so we don't have to call
4001 * vmalloc_sync_mappings() in each module's init.
4002 */
4003 wrapper_vmalloc_sync_mappings();
4004
4005 mutex_lock(&sessions_mutex);
4006 list_add_tail(&transport->node, &lttng_counter_transport_list);
4007 mutex_unlock(&sessions_mutex);
4008 }
4009 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4010
4011 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4012 {
4013 mutex_lock(&sessions_mutex);
4014 list_del(&transport->node);
4015 mutex_unlock(&sessions_mutex);
4016 }
4017 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4018
4019 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4020
4021 enum cpuhp_state lttng_hp_prepare;
4022 enum cpuhp_state lttng_hp_online;
4023
4024 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4025 {
4026 struct lttng_cpuhp_node *lttng_node;
4027
4028 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4029 switch (lttng_node->component) {
4030 case LTTNG_RING_BUFFER_FRONTEND:
4031 return 0;
4032 case LTTNG_RING_BUFFER_BACKEND:
4033 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4034 case LTTNG_RING_BUFFER_ITER:
4035 return 0;
4036 case LTTNG_CONTEXT_PERF_COUNTERS:
4037 return 0;
4038 default:
4039 return -EINVAL;
4040 }
4041 }
4042
4043 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4044 {
4045 struct lttng_cpuhp_node *lttng_node;
4046
4047 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4048 switch (lttng_node->component) {
4049 case LTTNG_RING_BUFFER_FRONTEND:
4050 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4051 case LTTNG_RING_BUFFER_BACKEND:
4052 return 0;
4053 case LTTNG_RING_BUFFER_ITER:
4054 return 0;
4055 case LTTNG_CONTEXT_PERF_COUNTERS:
4056 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4057 default:
4058 return -EINVAL;
4059 }
4060 }
4061
4062 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4063 {
4064 struct lttng_cpuhp_node *lttng_node;
4065
4066 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4067 switch (lttng_node->component) {
4068 case LTTNG_RING_BUFFER_FRONTEND:
4069 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4070 case LTTNG_RING_BUFFER_BACKEND:
4071 return 0;
4072 case LTTNG_RING_BUFFER_ITER:
4073 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4074 case LTTNG_CONTEXT_PERF_COUNTERS:
4075 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4076 default:
4077 return -EINVAL;
4078 }
4079 }
4080
4081 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4082 {
4083 struct lttng_cpuhp_node *lttng_node;
4084
4085 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4086 switch (lttng_node->component) {
4087 case LTTNG_RING_BUFFER_FRONTEND:
4088 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4089 case LTTNG_RING_BUFFER_BACKEND:
4090 return 0;
4091 case LTTNG_RING_BUFFER_ITER:
4092 return 0;
4093 case LTTNG_CONTEXT_PERF_COUNTERS:
4094 return 0;
4095 default:
4096 return -EINVAL;
4097 }
4098 }
4099
4100 static int __init lttng_init_cpu_hotplug(void)
4101 {
4102 int ret;
4103
4104 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4105 lttng_hotplug_prepare,
4106 lttng_hotplug_dead);
4107 if (ret < 0) {
4108 return ret;
4109 }
4110 lttng_hp_prepare = ret;
4111 lttng_rb_set_hp_prepare(ret);
4112
4113 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4114 lttng_hotplug_online,
4115 lttng_hotplug_offline);
4116 if (ret < 0) {
4117 cpuhp_remove_multi_state(lttng_hp_prepare);
4118 lttng_hp_prepare = 0;
4119 return ret;
4120 }
4121 lttng_hp_online = ret;
4122 lttng_rb_set_hp_online(ret);
4123
4124 return 0;
4125 }
4126
4127 static void __exit lttng_exit_cpu_hotplug(void)
4128 {
4129 lttng_rb_set_hp_online(0);
4130 cpuhp_remove_multi_state(lttng_hp_online);
4131 lttng_rb_set_hp_prepare(0);
4132 cpuhp_remove_multi_state(lttng_hp_prepare);
4133 }
4134
4135 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4136 static int lttng_init_cpu_hotplug(void)
4137 {
4138 return 0;
4139 }
4140 static void lttng_exit_cpu_hotplug(void)
4141 {
4142 }
4143 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4144
4145 static int __init lttng_events_init(void)
4146 {
4147 int ret;
4148
4149 ret = wrapper_get_pfnblock_flags_mask_init();
4150 if (ret)
4151 return ret;
4152 ret = lttng_probes_init();
4153 if (ret)
4154 return ret;
4155 ret = lttng_context_init();
4156 if (ret)
4157 return ret;
4158 ret = lttng_tracepoint_init();
4159 if (ret)
4160 goto error_tp;
4161 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4162 if (!event_recorder_cache) {
4163 ret = -ENOMEM;
4164 goto error_kmem_event_recorder;
4165 }
4166 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4167 if (!event_recorder_private_cache) {
4168 ret = -ENOMEM;
4169 goto error_kmem_event_recorder_private;
4170 }
4171 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4172 if (!event_notifier_cache) {
4173 ret = -ENOMEM;
4174 goto error_kmem_event_notifier;
4175 }
4176 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4177 if (!event_notifier_private_cache) {
4178 ret = -ENOMEM;
4179 goto error_kmem_event_notifier_private;
4180 }
4181 ret = lttng_abi_init();
4182 if (ret)
4183 goto error_abi;
4184 ret = lttng_logger_init();
4185 if (ret)
4186 goto error_logger;
4187 ret = lttng_init_cpu_hotplug();
4188 if (ret)
4189 goto error_hotplug;
4190 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4191 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4192 __stringify(LTTNG_MODULES_MINOR_VERSION),
4193 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4194 LTTNG_MODULES_EXTRAVERSION,
4195 LTTNG_VERSION_NAME,
4196 #ifdef LTTNG_EXTRA_VERSION_GIT
4197 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4198 #else
4199 "",
4200 #endif
4201 #ifdef LTTNG_EXTRA_VERSION_NAME
4202 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4203 #else
4204 "");
4205 #endif
4206 #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
4207 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
4208 #endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
4209 return 0;
4210
4211 error_hotplug:
4212 lttng_logger_exit();
4213 error_logger:
4214 lttng_abi_exit();
4215 error_abi:
4216 kmem_cache_destroy(event_notifier_private_cache);
4217 error_kmem_event_notifier_private:
4218 kmem_cache_destroy(event_notifier_cache);
4219 error_kmem_event_notifier:
4220 kmem_cache_destroy(event_recorder_private_cache);
4221 error_kmem_event_recorder_private:
4222 kmem_cache_destroy(event_recorder_cache);
4223 error_kmem_event_recorder:
4224 lttng_tracepoint_exit();
4225 error_tp:
4226 lttng_context_exit();
4227 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4228 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4229 __stringify(LTTNG_MODULES_MINOR_VERSION),
4230 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4231 LTTNG_MODULES_EXTRAVERSION,
4232 LTTNG_VERSION_NAME,
4233 #ifdef LTTNG_EXTRA_VERSION_GIT
4234 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4235 #else
4236 "",
4237 #endif
4238 #ifdef LTTNG_EXTRA_VERSION_NAME
4239 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4240 #else
4241 "");
4242 #endif
4243 return ret;
4244 }
4245
4246 module_init(lttng_events_init);
4247
4248 static void __exit lttng_events_exit(void)
4249 {
4250 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4251
4252 lttng_exit_cpu_hotplug();
4253 lttng_logger_exit();
4254 lttng_abi_exit();
4255 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4256 lttng_session_destroy(session_priv->pub);
4257 kmem_cache_destroy(event_recorder_cache);
4258 kmem_cache_destroy(event_recorder_private_cache);
4259 kmem_cache_destroy(event_notifier_cache);
4260 kmem_cache_destroy(event_notifier_private_cache);
4261 lttng_tracepoint_exit();
4262 lttng_context_exit();
4263 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4264 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4265 __stringify(LTTNG_MODULES_MINOR_VERSION),
4266 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4267 LTTNG_MODULES_EXTRAVERSION,
4268 LTTNG_VERSION_NAME,
4269 #ifdef LTTNG_EXTRA_VERSION_GIT
4270 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4271 #else
4272 "",
4273 #endif
4274 #ifdef LTTNG_EXTRA_VERSION_NAME
4275 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4276 #else
4277 "");
4278 #endif
4279 }
4280
4281 module_exit(lttng_events_exit);
4282
4283 #include <generated/patches.h>
4284 #ifdef LTTNG_EXTRA_VERSION_GIT
4285 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4286 #endif
4287 #ifdef LTTNG_EXTRA_VERSION_NAME
4288 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4289 #endif
4290 MODULE_LICENSE("GPL and additional rights");
4291 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4292 MODULE_DESCRIPTION("LTTng tracer");
4293 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4294 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4295 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4296 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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