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8d2bf46991d78703a2bbeed96333282211319600
[lttng-modules.git] / src / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
2 *
3 * lttng-events.c
4 *
5 * Holds LTTng per-session event registry.
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10 /*
11 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
12 * overrides a function with a define.
13 */
14 #include "wrapper/page_alloc.h"
15
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/jiffies.h>
21 #include <linux/utsname.h>
22 #include <linux/err.h>
23 #include <linux/seq_file.h>
24 #include <linux/file.h>
25 #include <linux/anon_inodes.h>
26 #include <wrapper/file.h>
27 #include <linux/uaccess.h>
28 #include <linux/vmalloc.h>
29 #include <linux/dmi.h>
30
31 #include <wrapper/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 #include <wrapper/time.h>
50
51 #define METADATA_CACHE_DEFAULT_SIZE 4096
52
53 static LIST_HEAD(sessions);
54 static LIST_HEAD(event_notifier_groups);
55 static LIST_HEAD(lttng_transport_list);
56 static LIST_HEAD(lttng_counter_transport_list);
57 /*
58 * Protect the sessions and metadata caches.
59 */
60 static DEFINE_MUTEX(sessions_mutex);
61 static struct kmem_cache *event_recorder_cache;
62 static struct kmem_cache *event_recorder_private_cache;
63 static struct kmem_cache *event_notifier_cache;
64 static struct kmem_cache *event_notifier_private_cache;
65
66 static void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session);
67 static void lttng_session_sync_event_enablers(struct lttng_kernel_session *session);
68 static void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler);
69 static void lttng_event_notifier_enabler_destroy(struct lttng_event_notifier_enabler *event_notifier_enabler);
70 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
71
72 static void _lttng_event_destroy(struct lttng_kernel_event_common *event);
73 static void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan);
74 static int _lttng_event_unregister(struct lttng_kernel_event_recorder *event);
75 static int _lttng_event_notifier_unregister(struct lttng_kernel_event_notifier *event_notifier);
76 static
77 int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
78 struct lttng_kernel_channel_buffer *chan,
79 struct lttng_kernel_event_recorder *event);
80 static
81 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session);
82 static
83 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
84 static
85 int _lttng_type_statedump(struct lttng_kernel_session *session,
86 const struct lttng_kernel_type_common *type,
87 enum lttng_kernel_string_encoding parent_encoding,
88 size_t nesting);
89 static
90 int _lttng_field_statedump(struct lttng_kernel_session *session,
91 const struct lttng_kernel_event_field *field,
92 size_t nesting, const char **prev_field_name_p);
93
94 void synchronize_trace(void)
95 {
96 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0))
97 synchronize_rcu();
98 #else
99 synchronize_sched();
100 #endif
101
102 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
103 #ifdef CONFIG_PREEMPT_RT_FULL
104 synchronize_rcu();
105 #endif
106 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
107 #ifdef CONFIG_PREEMPT_RT
108 synchronize_rcu();
109 #endif
110 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
111 }
112
113 void lttng_lock_sessions(void)
114 {
115 mutex_lock(&sessions_mutex);
116 }
117
118 void lttng_unlock_sessions(void)
119 {
120 mutex_unlock(&sessions_mutex);
121 }
122
123 static struct lttng_transport *lttng_transport_find(const char *name)
124 {
125 struct lttng_transport *transport;
126
127 list_for_each_entry(transport, &lttng_transport_list, node) {
128 if (!strcmp(transport->name, name))
129 return transport;
130 }
131 return NULL;
132 }
133
134 /*
135 * Called with sessions lock held.
136 */
137 int lttng_session_active(void)
138 {
139 struct lttng_kernel_session_private *iter;
140
141 list_for_each_entry(iter, &sessions, list) {
142 if (iter->pub->active)
143 return 1;
144 }
145 return 0;
146 }
147
148 struct lttng_kernel_session *lttng_session_create(void)
149 {
150 struct lttng_kernel_session *session;
151 struct lttng_kernel_session_private *session_priv;
152 struct lttng_metadata_cache *metadata_cache;
153 int i;
154
155 mutex_lock(&sessions_mutex);
156 session = lttng_kvzalloc(sizeof(*session), GFP_KERNEL);
157 if (!session)
158 goto err;
159 session_priv = lttng_kvzalloc(sizeof(*session_priv), GFP_KERNEL);
160 if (!session_priv)
161 goto err_free_session;
162 session->priv = session_priv;
163 session_priv->pub = session;
164
165 INIT_LIST_HEAD(&session_priv->chan);
166 INIT_LIST_HEAD(&session_priv->events);
167 lttng_guid_gen(&session_priv->uuid);
168
169 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
170 GFP_KERNEL);
171 if (!metadata_cache)
172 goto err_free_session_private;
173 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
174 if (!metadata_cache->data)
175 goto err_free_cache;
176 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
177 kref_init(&metadata_cache->refcount);
178 mutex_init(&metadata_cache->lock);
179 session_priv->metadata_cache = metadata_cache;
180 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
181 memcpy(&metadata_cache->uuid, &session_priv->uuid,
182 sizeof(metadata_cache->uuid));
183 INIT_LIST_HEAD(&session_priv->enablers_head);
184 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
185 INIT_HLIST_HEAD(&session_priv->events_ht.table[i]);
186 list_add(&session_priv->list, &sessions);
187
188 if (lttng_id_tracker_init(&session->pid_tracker, session, TRACKER_PID))
189 goto tracker_alloc_error;
190 if (lttng_id_tracker_init(&session->vpid_tracker, session, TRACKER_VPID))
191 goto tracker_alloc_error;
192 if (lttng_id_tracker_init(&session->uid_tracker, session, TRACKER_UID))
193 goto tracker_alloc_error;
194 if (lttng_id_tracker_init(&session->vuid_tracker, session, TRACKER_VUID))
195 goto tracker_alloc_error;
196 if (lttng_id_tracker_init(&session->gid_tracker, session, TRACKER_GID))
197 goto tracker_alloc_error;
198 if (lttng_id_tracker_init(&session->vgid_tracker, session, TRACKER_VGID))
199 goto tracker_alloc_error;
200
201 mutex_unlock(&sessions_mutex);
202
203 return session;
204
205 tracker_alloc_error:
206 lttng_id_tracker_fini(&session->pid_tracker);
207 lttng_id_tracker_fini(&session->vpid_tracker);
208 lttng_id_tracker_fini(&session->uid_tracker);
209 lttng_id_tracker_fini(&session->vuid_tracker);
210 lttng_id_tracker_fini(&session->gid_tracker);
211 lttng_id_tracker_fini(&session->vgid_tracker);
212 err_free_cache:
213 kfree(metadata_cache);
214 err_free_session_private:
215 lttng_kvfree(session_priv);
216 err_free_session:
217 lttng_kvfree(session);
218 err:
219 mutex_unlock(&sessions_mutex);
220 return NULL;
221 }
222
223 static
224 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
225 {
226 struct lttng_counter_transport *transport;
227
228 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
229 if (!strcmp(transport->name, name))
230 return transport;
231 }
232 return NULL;
233 }
234
235 struct lttng_counter *lttng_kernel_counter_create(
236 const char *counter_transport_name,
237 size_t number_dimensions, const size_t *dimensions_sizes)
238 {
239 struct lttng_counter *counter = NULL;
240 struct lttng_counter_transport *counter_transport = NULL;
241
242 counter_transport = lttng_counter_transport_find(counter_transport_name);
243 if (!counter_transport) {
244 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
245 counter_transport_name);
246 goto notransport;
247 }
248 if (!try_module_get(counter_transport->owner)) {
249 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
250 goto notransport;
251 }
252
253 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
254 if (!counter)
255 goto nomem;
256
257 /* Create event notifier error counter. */
258 counter->ops = &counter_transport->ops;
259 counter->transport = counter_transport;
260
261 counter->counter = counter->ops->counter_create(
262 number_dimensions, dimensions_sizes, 0);
263 if (!counter->counter) {
264 goto create_error;
265 }
266
267 return counter;
268
269 create_error:
270 lttng_kvfree(counter);
271 nomem:
272 if (counter_transport)
273 module_put(counter_transport->owner);
274 notransport:
275 return NULL;
276 }
277
278 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
279 {
280 struct lttng_transport *transport = NULL;
281 struct lttng_event_notifier_group *event_notifier_group;
282 const char *transport_name = "relay-event-notifier";
283 size_t subbuf_size = 4096; //TODO
284 size_t num_subbuf = 16; //TODO
285 unsigned int switch_timer_interval = 0;
286 unsigned int read_timer_interval = 0;
287 int i;
288
289 mutex_lock(&sessions_mutex);
290
291 transport = lttng_transport_find(transport_name);
292 if (!transport) {
293 printk(KERN_WARNING "LTTng: transport %s not found\n",
294 transport_name);
295 goto notransport;
296 }
297 if (!try_module_get(transport->owner)) {
298 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
299 transport_name);
300 goto notransport;
301 }
302
303 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
304 GFP_KERNEL);
305 if (!event_notifier_group)
306 goto nomem;
307
308 /*
309 * Initialize the ring buffer used to store event notifier
310 * notifications.
311 */
312 event_notifier_group->ops = &transport->ops;
313 event_notifier_group->chan = transport->ops.priv->channel_create(
314 transport_name, event_notifier_group, NULL,
315 subbuf_size, num_subbuf, switch_timer_interval,
316 read_timer_interval);
317 if (!event_notifier_group->chan)
318 goto create_error;
319
320 event_notifier_group->transport = transport;
321
322 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
323 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
324 for (i = 0; i < LTTNG_EVENT_NOTIFIER_HT_SIZE; i++)
325 INIT_HLIST_HEAD(&event_notifier_group->event_notifiers_ht.table[i]);
326
327 list_add(&event_notifier_group->node, &event_notifier_groups);
328
329 mutex_unlock(&sessions_mutex);
330
331 return event_notifier_group;
332
333 create_error:
334 lttng_kvfree(event_notifier_group);
335 nomem:
336 if (transport)
337 module_put(transport->owner);
338 notransport:
339 mutex_unlock(&sessions_mutex);
340 return NULL;
341 }
342
343 void metadata_cache_destroy(struct kref *kref)
344 {
345 struct lttng_metadata_cache *cache =
346 container_of(kref, struct lttng_metadata_cache, refcount);
347 vfree(cache->data);
348 kfree(cache);
349 }
350
351 void lttng_session_destroy(struct lttng_kernel_session *session)
352 {
353 struct lttng_kernel_channel_buffer_private *chan_priv, *tmpchan_priv;
354 struct lttng_kernel_event_recorder_private *event_recorder_priv, *tmpevent_recorder_priv;
355 struct lttng_metadata_stream *metadata_stream;
356 struct lttng_event_enabler *event_enabler, *tmp_event_enabler;
357 int ret;
358
359 mutex_lock(&sessions_mutex);
360 WRITE_ONCE(session->active, 0);
361 list_for_each_entry(chan_priv, &session->priv->chan, node) {
362 ret = lttng_syscalls_unregister_channel(chan_priv->pub);
363 WARN_ON(ret);
364 }
365 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
366 ret = _lttng_event_unregister(event_recorder_priv->pub);
367 WARN_ON(ret);
368 }
369 synchronize_trace(); /* Wait for in-flight events to complete */
370 list_for_each_entry(chan_priv, &session->priv->chan, node) {
371 ret = lttng_syscalls_destroy_event(chan_priv->pub);
372 WARN_ON(ret);
373 }
374 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
375 &session->priv->enablers_head, node)
376 lttng_event_enabler_destroy(event_enabler);
377 list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv, &session->priv->events, node)
378 _lttng_event_destroy(&event_recorder_priv->pub->parent);
379 list_for_each_entry_safe(chan_priv, tmpchan_priv, &session->priv->chan, node) {
380 BUG_ON(chan_priv->channel_type == METADATA_CHANNEL);
381 _lttng_channel_destroy(chan_priv->pub);
382 }
383 mutex_lock(&session->priv->metadata_cache->lock);
384 list_for_each_entry(metadata_stream, &session->priv->metadata_cache->metadata_stream, list)
385 _lttng_metadata_channel_hangup(metadata_stream);
386 mutex_unlock(&session->priv->metadata_cache->lock);
387 lttng_id_tracker_fini(&session->pid_tracker);
388 lttng_id_tracker_fini(&session->vpid_tracker);
389 lttng_id_tracker_fini(&session->uid_tracker);
390 lttng_id_tracker_fini(&session->vuid_tracker);
391 lttng_id_tracker_fini(&session->gid_tracker);
392 lttng_id_tracker_fini(&session->vgid_tracker);
393 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
394 list_del(&session->priv->list);
395 mutex_unlock(&sessions_mutex);
396 lttng_kvfree(session->priv);
397 lttng_kvfree(session);
398 }
399
400 void lttng_event_notifier_group_destroy(
401 struct lttng_event_notifier_group *event_notifier_group)
402 {
403 struct lttng_event_notifier_enabler *event_notifier_enabler, *tmp_event_notifier_enabler;
404 struct lttng_kernel_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
405 int ret;
406
407 if (!event_notifier_group)
408 return;
409
410 mutex_lock(&sessions_mutex);
411
412 ret = lttng_syscalls_unregister_event_notifier_group(event_notifier_group);
413 WARN_ON(ret);
414
415 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
416 &event_notifier_group->event_notifiers_head, node) {
417 ret = _lttng_event_notifier_unregister(event_notifier_priv->pub);
418 WARN_ON(ret);
419 }
420
421 /* Wait for in-flight event notifier to complete */
422 synchronize_trace();
423
424 irq_work_sync(&event_notifier_group->wakeup_pending);
425
426 kfree(event_notifier_group->sc_filter);
427
428 list_for_each_entry_safe(event_notifier_enabler, tmp_event_notifier_enabler,
429 &event_notifier_group->enablers_head, node)
430 lttng_event_notifier_enabler_destroy(event_notifier_enabler);
431
432 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
433 &event_notifier_group->event_notifiers_head, node)
434 _lttng_event_destroy(&event_notifier_priv->pub->parent);
435
436 if (event_notifier_group->error_counter) {
437 struct lttng_counter *error_counter = event_notifier_group->error_counter;
438
439 error_counter->ops->counter_destroy(error_counter->counter);
440 module_put(error_counter->transport->owner);
441 lttng_kvfree(error_counter);
442 event_notifier_group->error_counter = NULL;
443 }
444
445 event_notifier_group->ops->priv->channel_destroy(event_notifier_group->chan);
446 module_put(event_notifier_group->transport->owner);
447 list_del(&event_notifier_group->node);
448
449 mutex_unlock(&sessions_mutex);
450 lttng_kvfree(event_notifier_group);
451 }
452
453 int lttng_session_statedump(struct lttng_kernel_session *session)
454 {
455 int ret;
456
457 mutex_lock(&sessions_mutex);
458 ret = lttng_statedump_start(session);
459 mutex_unlock(&sessions_mutex);
460 return ret;
461 }
462
463 int lttng_session_enable(struct lttng_kernel_session *session)
464 {
465 int ret = 0;
466 struct lttng_kernel_channel_buffer_private *chan_priv;
467
468 mutex_lock(&sessions_mutex);
469 if (session->active) {
470 ret = -EBUSY;
471 goto end;
472 }
473
474 /* Set transient enabler state to "enabled" */
475 session->priv->tstate = 1;
476
477 /* We need to sync enablers with session before activation. */
478 lttng_session_sync_event_enablers(session);
479
480 /*
481 * Snapshot the number of events per channel to know the type of header
482 * we need to use.
483 */
484 list_for_each_entry(chan_priv, &session->priv->chan, node) {
485 if (chan_priv->header_type)
486 continue; /* don't change it if session stop/restart */
487 if (chan_priv->free_event_id < 31)
488 chan_priv->header_type = 1; /* compact */
489 else
490 chan_priv->header_type = 2; /* large */
491 }
492
493 /* Clear each stream's quiescent state. */
494 list_for_each_entry(chan_priv, &session->priv->chan, node) {
495 if (chan_priv->channel_type != METADATA_CHANNEL)
496 lib_ring_buffer_clear_quiescent_channel(chan_priv->rb_chan);
497 }
498
499 WRITE_ONCE(session->active, 1);
500 WRITE_ONCE(session->priv->been_active, 1);
501 ret = _lttng_session_metadata_statedump(session);
502 if (ret) {
503 WRITE_ONCE(session->active, 0);
504 goto end;
505 }
506 ret = lttng_statedump_start(session);
507 if (ret)
508 WRITE_ONCE(session->active, 0);
509 end:
510 mutex_unlock(&sessions_mutex);
511 return ret;
512 }
513
514 int lttng_session_disable(struct lttng_kernel_session *session)
515 {
516 int ret = 0;
517 struct lttng_kernel_channel_buffer_private *chan_priv;
518
519 mutex_lock(&sessions_mutex);
520 if (!session->active) {
521 ret = -EBUSY;
522 goto end;
523 }
524 WRITE_ONCE(session->active, 0);
525
526 /* Set transient enabler state to "disabled" */
527 session->priv->tstate = 0;
528 lttng_session_sync_event_enablers(session);
529
530 /* Set each stream's quiescent state. */
531 list_for_each_entry(chan_priv, &session->priv->chan, node) {
532 if (chan_priv->channel_type != METADATA_CHANNEL)
533 lib_ring_buffer_set_quiescent_channel(chan_priv->rb_chan);
534 }
535 end:
536 mutex_unlock(&sessions_mutex);
537 return ret;
538 }
539
540 int lttng_session_metadata_regenerate(struct lttng_kernel_session *session)
541 {
542 int ret = 0;
543 struct lttng_kernel_channel_buffer_private *chan_priv;
544 struct lttng_kernel_event_recorder_private *event_recorder_priv;
545 struct lttng_metadata_cache *cache = session->priv->metadata_cache;
546 struct lttng_metadata_stream *stream;
547
548 mutex_lock(&sessions_mutex);
549 if (!session->active) {
550 ret = -EBUSY;
551 goto end;
552 }
553
554 mutex_lock(&cache->lock);
555 memset(cache->data, 0, cache->cache_alloc);
556 cache->metadata_written = 0;
557 cache->version++;
558 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list) {
559 stream->metadata_out = 0;
560 stream->metadata_in = 0;
561 }
562 mutex_unlock(&cache->lock);
563
564 session->priv->metadata_dumped = 0;
565 list_for_each_entry(chan_priv, &session->priv->chan, node) {
566 chan_priv->metadata_dumped = 0;
567 }
568
569 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
570 event_recorder_priv->metadata_dumped = 0;
571 }
572
573 ret = _lttng_session_metadata_statedump(session);
574
575 end:
576 mutex_unlock(&sessions_mutex);
577 return ret;
578 }
579
580 int lttng_channel_enable(struct lttng_kernel_channel_buffer *channel)
581 {
582 int ret = 0;
583
584 mutex_lock(&sessions_mutex);
585 if (channel->priv->channel_type == METADATA_CHANNEL) {
586 ret = -EPERM;
587 goto end;
588 }
589 if (channel->parent.enabled) {
590 ret = -EEXIST;
591 goto end;
592 }
593 /* Set transient enabler state to "enabled" */
594 channel->priv->parent.tstate = 1;
595 lttng_session_sync_event_enablers(channel->parent.session);
596 /* Set atomically the state to "enabled" */
597 WRITE_ONCE(channel->parent.enabled, 1);
598 end:
599 mutex_unlock(&sessions_mutex);
600 return ret;
601 }
602
603 int lttng_channel_disable(struct lttng_kernel_channel_buffer *channel)
604 {
605 int ret = 0;
606
607 mutex_lock(&sessions_mutex);
608 if (channel->priv->channel_type == METADATA_CHANNEL) {
609 ret = -EPERM;
610 goto end;
611 }
612 if (!channel->parent.enabled) {
613 ret = -EEXIST;
614 goto end;
615 }
616 /* Set atomically the state to "disabled" */
617 WRITE_ONCE(channel->parent.enabled, 0);
618 /* Set transient enabler state to "enabled" */
619 channel->priv->parent.tstate = 0;
620 lttng_session_sync_event_enablers(channel->parent.session);
621 end:
622 mutex_unlock(&sessions_mutex);
623 return ret;
624 }
625
626 int lttng_event_enable(struct lttng_kernel_event_common *event)
627 {
628 int ret = 0;
629
630 mutex_lock(&sessions_mutex);
631 switch (event->type) {
632 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
633 {
634 struct lttng_kernel_event_recorder *event_recorder =
635 container_of(event, struct lttng_kernel_event_recorder, parent);
636
637 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
638 ret = -EPERM;
639 goto end;
640 }
641 break;
642 }
643 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
644 switch (event->priv->instrumentation) {
645 case LTTNG_KERNEL_ABI_KRETPROBE:
646 ret = -EINVAL;
647 goto end;
648 default:
649 break;
650 }
651 break;
652 default:
653 break;
654 }
655
656 if (event->enabled) {
657 ret = -EEXIST;
658 goto end;
659 }
660 switch (event->priv->instrumentation) {
661 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
662 case LTTNG_KERNEL_ABI_SYSCALL:
663 ret = -EINVAL;
664 break;
665
666 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
667 case LTTNG_KERNEL_ABI_UPROBE:
668 WRITE_ONCE(event->enabled, 1);
669 break;
670
671 case LTTNG_KERNEL_ABI_KRETPROBE:
672 ret = lttng_kretprobes_event_enable_state(event, 1);
673 break;
674
675 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
676 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
677 default:
678 WARN_ON_ONCE(1);
679 ret = -EINVAL;
680 }
681 end:
682 mutex_unlock(&sessions_mutex);
683 return ret;
684 }
685
686 int lttng_event_disable(struct lttng_kernel_event_common *event)
687 {
688 int ret = 0;
689
690 mutex_lock(&sessions_mutex);
691 switch (event->type) {
692 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
693 {
694 struct lttng_kernel_event_recorder *event_recorder =
695 container_of(event, struct lttng_kernel_event_recorder, parent);
696
697 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
698 ret = -EPERM;
699 goto end;
700 }
701 break;
702 }
703 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
704 switch (event->priv->instrumentation) {
705 case LTTNG_KERNEL_ABI_KRETPROBE:
706 ret = -EINVAL;
707 goto end;
708 default:
709 break;
710 }
711 break;
712 default:
713 break;
714 }
715
716 if (!event->enabled) {
717 ret = -EEXIST;
718 goto end;
719 }
720 switch (event->priv->instrumentation) {
721 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
722 case LTTNG_KERNEL_ABI_SYSCALL:
723 ret = -EINVAL;
724 break;
725
726 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
727 case LTTNG_KERNEL_ABI_UPROBE:
728 WRITE_ONCE(event->enabled, 0);
729 break;
730
731 case LTTNG_KERNEL_ABI_KRETPROBE:
732 ret = lttng_kretprobes_event_enable_state(event, 0);
733 break;
734
735 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
736 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
737 default:
738 WARN_ON_ONCE(1);
739 ret = -EINVAL;
740 }
741 end:
742 mutex_unlock(&sessions_mutex);
743 return ret;
744 }
745
746 struct lttng_kernel_channel_buffer *lttng_channel_create(struct lttng_kernel_session *session,
747 const char *transport_name,
748 void *buf_addr,
749 size_t subbuf_size, size_t num_subbuf,
750 unsigned int switch_timer_interval,
751 unsigned int read_timer_interval,
752 enum channel_type channel_type)
753 {
754 struct lttng_kernel_channel_buffer *chan;
755 struct lttng_kernel_channel_buffer_private *chan_priv;
756 struct lttng_transport *transport = NULL;
757
758 mutex_lock(&sessions_mutex);
759 if (session->priv->been_active && channel_type != METADATA_CHANNEL)
760 goto active; /* Refuse to add channel to active session */
761 transport = lttng_transport_find(transport_name);
762 if (!transport) {
763 printk(KERN_WARNING "LTTng: transport %s not found\n",
764 transport_name);
765 goto notransport;
766 }
767 if (!try_module_get(transport->owner)) {
768 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
769 goto notransport;
770 }
771 chan = kzalloc(sizeof(struct lttng_kernel_channel_buffer), GFP_KERNEL);
772 if (!chan)
773 goto nomem;
774 chan_priv = kzalloc(sizeof(struct lttng_kernel_channel_buffer_private), GFP_KERNEL);
775 if (!chan_priv)
776 goto nomem_priv;
777 chan->priv = chan_priv;
778 chan_priv->pub = chan;
779 chan->parent.type = LTTNG_KERNEL_CHANNEL_TYPE_BUFFER;
780 chan->parent.session = session;
781 chan->priv->id = session->priv->free_chan_id++;
782 chan->ops = &transport->ops;
783 /*
784 * Note: the channel creation op already writes into the packet
785 * headers. Therefore the "chan" information used as input
786 * should be already accessible.
787 */
788 chan->priv->rb_chan = transport->ops.priv->channel_create(transport_name,
789 chan, buf_addr, subbuf_size, num_subbuf,
790 switch_timer_interval, read_timer_interval);
791 if (!chan->priv->rb_chan)
792 goto create_error;
793 chan->priv->parent.tstate = 1;
794 chan->parent.enabled = 1;
795 chan->priv->transport = transport;
796 chan->priv->channel_type = channel_type;
797 list_add(&chan->priv->node, &session->priv->chan);
798 mutex_unlock(&sessions_mutex);
799 return chan;
800
801 create_error:
802 kfree(chan_priv);
803 nomem_priv:
804 kfree(chan);
805 nomem:
806 if (transport)
807 module_put(transport->owner);
808 notransport:
809 active:
810 mutex_unlock(&sessions_mutex);
811 return NULL;
812 }
813
814 /*
815 * Only used internally at session destruction for per-cpu channels, and
816 * when metadata channel is released.
817 * Needs to be called with sessions mutex held.
818 */
819 static
820 void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan)
821 {
822 chan->ops->priv->channel_destroy(chan->priv->rb_chan);
823 module_put(chan->priv->transport->owner);
824 list_del(&chan->priv->node);
825 lttng_kernel_destroy_context(chan->priv->ctx);
826 kfree(chan->priv);
827 kfree(chan);
828 }
829
830 void lttng_metadata_channel_destroy(struct lttng_kernel_channel_buffer *chan)
831 {
832 BUG_ON(chan->priv->channel_type != METADATA_CHANNEL);
833
834 /* Protect the metadata cache with the sessions_mutex. */
835 mutex_lock(&sessions_mutex);
836 _lttng_channel_destroy(chan);
837 mutex_unlock(&sessions_mutex);
838 }
839 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
840
841 static
842 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
843 {
844 stream->finalized = 1;
845 wake_up_interruptible(&stream->read_wait);
846 }
847
848
849 /*
850 * Supports event creation while tracing session is active.
851 * Needs to be called with sessions mutex held.
852 */
853 struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
854 struct lttng_kernel_abi_event *event_param,
855 const struct lttng_kernel_event_desc *event_desc,
856 enum lttng_kernel_abi_instrumentation itype)
857 {
858 struct lttng_kernel_session *session = chan->parent.session;
859 struct lttng_kernel_event_recorder *event_recorder;
860 struct lttng_kernel_event_recorder_private *event_recorder_priv;
861 const char *event_name;
862 struct hlist_head *head;
863 int ret;
864
865 if (chan->priv->free_event_id == -1U) {
866 ret = -EMFILE;
867 goto full;
868 }
869
870 switch (itype) {
871 case LTTNG_KERNEL_ABI_TRACEPOINT:
872 event_name = event_desc->event_name;
873 break;
874
875 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
876 case LTTNG_KERNEL_ABI_UPROBE: /* Fall-through */
877 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
878 case LTTNG_KERNEL_ABI_SYSCALL:
879 event_name = event_param->name;
880 break;
881
882 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
883 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
884 default:
885 WARN_ON_ONCE(1);
886 ret = -EINVAL;
887 goto type_error;
888 }
889
890 head = utils_borrow_hash_table_bucket(session->priv->events_ht.table,
891 LTTNG_EVENT_HT_SIZE, event_name);
892 lttng_hlist_for_each_entry(event_recorder_priv, head, hlist) {
893 WARN_ON_ONCE(!event_recorder_priv->parent.desc);
894 if (!strncmp(event_recorder_priv->parent.desc->event_name, event_name,
895 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
896 && chan == event_recorder_priv->pub->chan) {
897 ret = -EEXIST;
898 goto exist;
899 }
900 }
901
902 event_recorder = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
903 if (!event_recorder) {
904 ret = -ENOMEM;
905 goto cache_error;
906 }
907 event_recorder_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
908 if (!event_recorder_priv) {
909 ret = -ENOMEM;
910 goto cache_private_error;
911 }
912 event_recorder_priv->pub = event_recorder;
913 event_recorder_priv->parent.pub = &event_recorder->parent;
914 event_recorder->priv = event_recorder_priv;
915 event_recorder->parent.priv = &event_recorder_priv->parent;
916 event_recorder->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
917
918 event_recorder->parent.run_filter = lttng_kernel_interpret_event_filter;
919 event_recorder->chan = chan;
920 event_recorder->priv->id = chan->priv->free_event_id++;
921 event_recorder->priv->parent.instrumentation = itype;
922 INIT_LIST_HEAD(&event_recorder->priv->parent.filter_bytecode_runtime_head);
923 INIT_LIST_HEAD(&event_recorder->priv->parent.enablers_ref_head);
924
925 switch (itype) {
926 case LTTNG_KERNEL_ABI_TRACEPOINT:
927 /* Event will be enabled by enabler sync. */
928 event_recorder->parent.enabled = 0;
929 event_recorder->priv->parent.registered = 0;
930 event_recorder->priv->parent.desc = lttng_event_desc_get(event_name);
931 if (!event_recorder->priv->parent.desc) {
932 ret = -ENOENT;
933 goto register_error;
934 }
935 /* Populate lttng_event structure before event registration. */
936 smp_wmb();
937 break;
938
939 case LTTNG_KERNEL_ABI_KPROBE:
940 /*
941 * Needs to be explicitly enabled after creation, since
942 * we may want to apply filters.
943 */
944 event_recorder->parent.enabled = 0;
945 event_recorder->priv->parent.registered = 1;
946 /*
947 * Populate lttng_event structure before event
948 * registration.
949 */
950 smp_wmb();
951 ret = lttng_kprobes_register_event(event_name,
952 event_param->u.kprobe.symbol_name,
953 event_param->u.kprobe.offset,
954 event_param->u.kprobe.addr,
955 event_recorder);
956 if (ret) {
957 ret = -EINVAL;
958 goto register_error;
959 }
960 ret = try_module_get(event_recorder->priv->parent.desc->owner);
961 WARN_ON_ONCE(!ret);
962 break;
963
964 case LTTNG_KERNEL_ABI_KRETPROBE:
965 {
966 struct lttng_kernel_event_recorder *event_recorder_return;
967 struct lttng_kernel_event_recorder_private *event_recorder_return_priv;
968
969 /* kretprobe defines 2 events */
970 /*
971 * Needs to be explicitly enabled after creation, since
972 * we may want to apply filters.
973 */
974 event_recorder->parent.enabled = 0;
975 event_recorder->priv->parent.registered = 1;
976
977 event_recorder_return = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
978 if (!event_recorder_return) {
979 ret = -ENOMEM;
980 goto register_error;
981 }
982 event_recorder_return_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
983 if (!event_recorder_return_priv) {
984 kmem_cache_free(event_recorder_cache, event_recorder_return);
985 ret = -ENOMEM;
986 goto register_error;
987 }
988 event_recorder_return_priv->pub = event_recorder_return;
989 event_recorder_return_priv->parent.pub = &event_recorder_return->parent;
990 event_recorder_return->priv = event_recorder_return_priv;
991 event_recorder_return->parent.priv = &event_recorder_return_priv->parent;
992 event_recorder_return->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
993
994 event_recorder_return->parent.run_filter = lttng_kernel_interpret_event_filter;
995 event_recorder_return->chan = chan;
996 event_recorder_return->priv->id = chan->priv->free_event_id++;
997 event_recorder_return->priv->parent.instrumentation = itype;
998 event_recorder_return->parent.enabled = 0;
999 event_recorder_return->priv->parent.registered = 1;
1000 INIT_LIST_HEAD(&event_recorder_return->priv->parent.filter_bytecode_runtime_head);
1001 INIT_LIST_HEAD(&event_recorder_return->priv->parent.enablers_ref_head);
1002 /*
1003 * Populate lttng_event structure before kretprobe registration.
1004 */
1005 smp_wmb();
1006 ret = lttng_kretprobes_register(event_name,
1007 event_param->u.kretprobe.symbol_name,
1008 event_param->u.kretprobe.offset,
1009 event_param->u.kretprobe.addr,
1010 event_recorder, event_recorder_return);
1011 if (ret) {
1012 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
1013 kmem_cache_free(event_recorder_cache, event_recorder_return);
1014 ret = -EINVAL;
1015 goto register_error;
1016 }
1017 /* Take 2 refs on the module: one per event. */
1018 ret = try_module_get(event_recorder->priv->parent.desc->owner);
1019 WARN_ON_ONCE(!ret);
1020 ret = try_module_get(event_recorder_return->priv->parent.desc->owner);
1021 WARN_ON_ONCE(!ret);
1022 ret = _lttng_event_metadata_statedump(chan->parent.session, chan,
1023 event_recorder_return);
1024 WARN_ON_ONCE(ret > 0);
1025 if (ret) {
1026 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
1027 kmem_cache_free(event_recorder_cache, event_recorder_return);
1028 module_put(event_recorder_return->priv->parent.desc->owner);
1029 module_put(event_recorder->priv->parent.desc->owner);
1030 goto statedump_error;
1031 }
1032 list_add(&event_recorder_return->priv->node, &chan->parent.session->priv->events);
1033 break;
1034 }
1035
1036 case LTTNG_KERNEL_ABI_SYSCALL:
1037 /*
1038 * Needs to be explicitly enabled after creation, since
1039 * we may want to apply filters.
1040 */
1041 event_recorder->parent.enabled = 0;
1042 event_recorder->priv->parent.registered = 0;
1043 event_recorder->priv->parent.desc = event_desc;
1044 switch (event_param->u.syscall.entryexit) {
1045 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1046 ret = -EINVAL;
1047 goto register_error;
1048 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1049 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1050 break;
1051 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1052 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1053 break;
1054 }
1055 switch (event_param->u.syscall.abi) {
1056 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1057 ret = -EINVAL;
1058 goto register_error;
1059 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1060 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1061 break;
1062 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1063 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1064 break;
1065 }
1066 if (!event_recorder->priv->parent.desc) {
1067 ret = -EINVAL;
1068 goto register_error;
1069 }
1070 break;
1071
1072 case LTTNG_KERNEL_ABI_UPROBE:
1073 /*
1074 * Needs to be explicitly enabled after creation, since
1075 * we may want to apply filters.
1076 */
1077 event_recorder->parent.enabled = 0;
1078 event_recorder->priv->parent.registered = 1;
1079
1080 /*
1081 * Populate lttng_event structure before event
1082 * registration.
1083 */
1084 smp_wmb();
1085
1086 ret = lttng_uprobes_register_event(event_param->name,
1087 event_param->u.uprobe.fd,
1088 event_recorder);
1089 if (ret)
1090 goto register_error;
1091 ret = try_module_get(event_recorder->priv->parent.desc->owner);
1092 WARN_ON_ONCE(!ret);
1093 break;
1094
1095 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1096 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1097 default:
1098 WARN_ON_ONCE(1);
1099 ret = -EINVAL;
1100 goto register_error;
1101 }
1102 ret = _lttng_event_metadata_statedump(chan->parent.session, chan, event_recorder);
1103 WARN_ON_ONCE(ret > 0);
1104 if (ret) {
1105 goto statedump_error;
1106 }
1107 hlist_add_head(&event_recorder->priv->hlist, head);
1108 list_add(&event_recorder->priv->node, &chan->parent.session->priv->events);
1109 return event_recorder;
1110
1111 statedump_error:
1112 /* If a statedump error occurs, events will not be readable. */
1113 register_error:
1114 kmem_cache_free(event_recorder_private_cache, event_recorder_priv);
1115 cache_private_error:
1116 kmem_cache_free(event_recorder_cache, event_recorder);
1117 cache_error:
1118 exist:
1119 type_error:
1120 full:
1121 return ERR_PTR(ret);
1122 }
1123
1124 struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
1125 const struct lttng_kernel_event_desc *event_desc,
1126 uint64_t token, uint64_t error_counter_index,
1127 struct lttng_event_notifier_group *event_notifier_group,
1128 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1129 enum lttng_kernel_abi_instrumentation itype)
1130 {
1131 struct lttng_kernel_event_notifier *event_notifier;
1132 struct lttng_kernel_event_notifier_private *event_notifier_priv;
1133 struct lttng_counter *error_counter;
1134 const char *event_name;
1135 struct hlist_head *head;
1136 int ret;
1137
1138 switch (itype) {
1139 case LTTNG_KERNEL_ABI_TRACEPOINT:
1140 event_name = event_desc->event_name;
1141 break;
1142
1143 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
1144 case LTTNG_KERNEL_ABI_UPROBE: /* Fall-through */
1145 case LTTNG_KERNEL_ABI_SYSCALL:
1146 event_name = event_notifier_param->event.name;
1147 break;
1148
1149 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1150 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1151 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1152 default:
1153 WARN_ON_ONCE(1);
1154 ret = -EINVAL;
1155 goto type_error;
1156 }
1157
1158 head = utils_borrow_hash_table_bucket(event_notifier_group->event_notifiers_ht.table,
1159 LTTNG_EVENT_NOTIFIER_HT_SIZE, event_name);
1160 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
1161 WARN_ON_ONCE(!event_notifier_priv->parent.desc);
1162 if (!strncmp(event_notifier_priv->parent.desc->event_name, event_name,
1163 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
1164 && event_notifier_group == event_notifier_priv->group
1165 && token == event_notifier_priv->parent.user_token) {
1166 ret = -EEXIST;
1167 goto exist;
1168 }
1169 }
1170
1171 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
1172 if (!event_notifier) {
1173 ret = -ENOMEM;
1174 goto cache_error;
1175 }
1176 event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
1177 if (!event_notifier_priv) {
1178 ret = -ENOMEM;
1179 goto cache_private_error;
1180 }
1181 event_notifier_priv->pub = event_notifier;
1182 event_notifier_priv->parent.pub = &event_notifier->parent;
1183 event_notifier->priv = event_notifier_priv;
1184 event_notifier->parent.priv = &event_notifier_priv->parent;
1185 event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
1186
1187 event_notifier->priv->group = event_notifier_group;
1188 event_notifier->priv->parent.user_token = token;
1189 event_notifier->priv->error_counter_index = error_counter_index;
1190 event_notifier->priv->num_captures = 0;
1191 event_notifier->priv->parent.instrumentation = itype;
1192 event_notifier->notification_send = lttng_event_notifier_notification_send;
1193 INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
1194 INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
1195 INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
1196 event_notifier->parent.run_filter = lttng_kernel_interpret_event_filter;
1197
1198 switch (itype) {
1199 case LTTNG_KERNEL_ABI_TRACEPOINT:
1200 /* Event will be enabled by enabler sync. */
1201 event_notifier->parent.enabled = 0;
1202 event_notifier->priv->parent.registered = 0;
1203 event_notifier->priv->parent.desc = lttng_event_desc_get(event_name);
1204 if (!event_notifier->priv->parent.desc) {
1205 ret = -ENOENT;
1206 goto register_error;
1207 }
1208 /* Populate lttng_event_notifier structure before event registration. */
1209 smp_wmb();
1210 break;
1211
1212 case LTTNG_KERNEL_ABI_KPROBE:
1213 /*
1214 * Needs to be explicitly enabled after creation, since
1215 * we may want to apply filters.
1216 */
1217 event_notifier->parent.enabled = 0;
1218 event_notifier->priv->parent.registered = 1;
1219 /*
1220 * Populate lttng_event_notifier structure before event
1221 * registration.
1222 */
1223 smp_wmb();
1224 ret = lttng_kprobes_register_event_notifier(
1225 event_notifier_param->event.u.kprobe.symbol_name,
1226 event_notifier_param->event.u.kprobe.offset,
1227 event_notifier_param->event.u.kprobe.addr,
1228 event_notifier);
1229 if (ret) {
1230 ret = -EINVAL;
1231 goto register_error;
1232 }
1233 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1234 WARN_ON_ONCE(!ret);
1235 break;
1236
1237 case LTTNG_KERNEL_ABI_SYSCALL:
1238 /*
1239 * Needs to be explicitly enabled after creation, since
1240 * we may want to apply filters.
1241 */
1242 event_notifier->parent.enabled = 0;
1243 event_notifier->priv->parent.registered = 0;
1244 event_notifier->priv->parent.desc = event_desc;
1245 switch (event_notifier_param->event.u.syscall.entryexit) {
1246 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1247 ret = -EINVAL;
1248 goto register_error;
1249 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1250 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1251 break;
1252 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1253 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1254 break;
1255 }
1256 switch (event_notifier_param->event.u.syscall.abi) {
1257 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1258 ret = -EINVAL;
1259 goto register_error;
1260 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1261 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1262 break;
1263 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1264 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1265 break;
1266 }
1267
1268 if (!event_notifier->priv->parent.desc) {
1269 ret = -EINVAL;
1270 goto register_error;
1271 }
1272 break;
1273
1274 case LTTNG_KERNEL_ABI_UPROBE:
1275 /*
1276 * Needs to be explicitly enabled after creation, since
1277 * we may want to apply filters.
1278 */
1279 event_notifier->parent.enabled = 0;
1280 event_notifier->priv->parent.registered = 1;
1281
1282 /*
1283 * Populate lttng_event_notifier structure before
1284 * event_notifier registration.
1285 */
1286 smp_wmb();
1287
1288 ret = lttng_uprobes_register_event_notifier(
1289 event_notifier_param->event.name,
1290 event_notifier_param->event.u.uprobe.fd,
1291 event_notifier);
1292 if (ret)
1293 goto register_error;
1294 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1295 WARN_ON_ONCE(!ret);
1296 break;
1297
1298 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1299 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1300 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1301 default:
1302 WARN_ON_ONCE(1);
1303 ret = -EINVAL;
1304 goto register_error;
1305 }
1306
1307 list_add(&event_notifier->priv->node, &event_notifier_group->event_notifiers_head);
1308 hlist_add_head(&event_notifier->priv->hlist, head);
1309
1310 /*
1311 * Clear the error counter bucket. The sessiond keeps track of which
1312 * bucket is currently in use. We trust it. The session lock
1313 * synchronizes against concurrent creation of the error
1314 * counter.
1315 */
1316 error_counter = event_notifier_group->error_counter;
1317 if (error_counter) {
1318 size_t dimension_index[1];
1319
1320 /*
1321 * Check that the index is within the boundary of the counter.
1322 */
1323 if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
1324 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1325 event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
1326 ret = -EINVAL;
1327 goto register_error;
1328 }
1329
1330 dimension_index[0] = event_notifier->priv->error_counter_index;
1331 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1332 if (ret) {
1333 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1334 event_notifier->priv->error_counter_index);
1335 goto register_error;
1336 }
1337 }
1338
1339 return event_notifier;
1340
1341 register_error:
1342 kmem_cache_free(event_notifier_private_cache, event_notifier_priv);
1343 cache_private_error:
1344 kmem_cache_free(event_notifier_cache, event_notifier);
1345 cache_error:
1346 exist:
1347 type_error:
1348 return ERR_PTR(ret);
1349 }
1350
1351 int lttng_kernel_counter_read(struct lttng_counter *counter,
1352 const size_t *dim_indexes, int32_t cpu,
1353 int64_t *val, bool *overflow, bool *underflow)
1354 {
1355 return counter->ops->counter_read(counter->counter, dim_indexes,
1356 cpu, val, overflow, underflow);
1357 }
1358
1359 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1360 const size_t *dim_indexes, int64_t *val,
1361 bool *overflow, bool *underflow)
1362 {
1363 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1364 val, overflow, underflow);
1365 }
1366
1367 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1368 const size_t *dim_indexes)
1369 {
1370 return counter->ops->counter_clear(counter->counter, dim_indexes);
1371 }
1372
1373 struct lttng_kernel_event_recorder *lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
1374 struct lttng_kernel_abi_event *event_param,
1375 const struct lttng_kernel_event_desc *event_desc,
1376 enum lttng_kernel_abi_instrumentation itype)
1377 {
1378 struct lttng_kernel_event_recorder *event;
1379
1380 mutex_lock(&sessions_mutex);
1381 event = _lttng_kernel_event_recorder_create(chan, event_param, event_desc, itype);
1382 mutex_unlock(&sessions_mutex);
1383 return event;
1384 }
1385
1386 struct lttng_kernel_event_notifier *lttng_event_notifier_create(
1387 const struct lttng_kernel_event_desc *event_desc,
1388 uint64_t id, uint64_t error_counter_index,
1389 struct lttng_event_notifier_group *event_notifier_group,
1390 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1391 enum lttng_kernel_abi_instrumentation itype)
1392 {
1393 struct lttng_kernel_event_notifier *event_notifier;
1394
1395 mutex_lock(&sessions_mutex);
1396 event_notifier = _lttng_event_notifier_create(event_desc, id,
1397 error_counter_index, event_notifier_group,
1398 event_notifier_param, itype);
1399 mutex_unlock(&sessions_mutex);
1400 return event_notifier;
1401 }
1402
1403 /* Only used for tracepoints for now. */
1404 static
1405 void register_event(struct lttng_kernel_event_recorder *event_recorder)
1406 {
1407 const struct lttng_kernel_event_desc *desc;
1408 int ret = -EINVAL;
1409
1410 if (event_recorder->priv->parent.registered)
1411 return;
1412
1413 desc = event_recorder->priv->parent.desc;
1414 switch (event_recorder->priv->parent.instrumentation) {
1415 case LTTNG_KERNEL_ABI_TRACEPOINT:
1416 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1417 desc->tp_class->probe_callback,
1418 event_recorder);
1419 break;
1420
1421 case LTTNG_KERNEL_ABI_SYSCALL:
1422 ret = lttng_syscall_filter_enable_event(event_recorder->chan, event_recorder);
1423 break;
1424
1425 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
1426 case LTTNG_KERNEL_ABI_UPROBE: /* Fall-through */
1427 case LTTNG_KERNEL_ABI_KRETPROBE:
1428 ret = 0;
1429 break;
1430
1431 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1432 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1433 default:
1434 WARN_ON_ONCE(1);
1435 }
1436 if (!ret)
1437 event_recorder->priv->parent.registered = 1;
1438 }
1439
1440 /*
1441 * Only used internally at session destruction.
1442 */
1443 int _lttng_event_unregister(struct lttng_kernel_event_recorder *event_recorder)
1444 {
1445 struct lttng_kernel_event_common_private *event_priv = &event_recorder->priv->parent;
1446 const struct lttng_kernel_event_desc *desc;
1447 int ret = -EINVAL;
1448
1449 if (!event_priv->registered)
1450 return 0;
1451
1452 desc = event_priv->desc;
1453 switch (event_priv->instrumentation) {
1454 case LTTNG_KERNEL_ABI_TRACEPOINT:
1455 ret = lttng_wrapper_tracepoint_probe_unregister(event_priv->desc->event_kname,
1456 event_priv->desc->tp_class->probe_callback,
1457 event_recorder);
1458 break;
1459
1460 case LTTNG_KERNEL_ABI_KPROBE:
1461 lttng_kprobes_unregister_event(event_recorder);
1462 ret = 0;
1463 break;
1464
1465 case LTTNG_KERNEL_ABI_KRETPROBE:
1466 lttng_kretprobes_unregister(event_recorder);
1467 ret = 0;
1468 break;
1469
1470 case LTTNG_KERNEL_ABI_SYSCALL:
1471 ret = lttng_syscall_filter_disable_event(event_recorder->chan, event_recorder);
1472 break;
1473
1474 case LTTNG_KERNEL_ABI_NOOP:
1475 ret = 0;
1476 break;
1477
1478 case LTTNG_KERNEL_ABI_UPROBE:
1479 lttng_uprobes_unregister_event(event_recorder);
1480 ret = 0;
1481 break;
1482
1483 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1484 default:
1485 WARN_ON_ONCE(1);
1486 }
1487 if (!ret)
1488 event_priv->registered = 0;
1489 return ret;
1490 }
1491
1492 /* Only used for tracepoints for now. */
1493 static
1494 void register_event_notifier(struct lttng_kernel_event_notifier *event_notifier)
1495 {
1496 const struct lttng_kernel_event_desc *desc;
1497 int ret = -EINVAL;
1498
1499 if (event_notifier->priv->parent.registered)
1500 return;
1501
1502 desc = event_notifier->priv->parent.desc;
1503 switch (event_notifier->priv->parent.instrumentation) {
1504 case LTTNG_KERNEL_ABI_TRACEPOINT:
1505 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1506 desc->tp_class->probe_callback,
1507 event_notifier);
1508 break;
1509
1510 case LTTNG_KERNEL_ABI_SYSCALL:
1511 ret = lttng_syscall_filter_enable_event_notifier(event_notifier);
1512 break;
1513
1514 case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
1515 case LTTNG_KERNEL_ABI_UPROBE:
1516 ret = 0;
1517 break;
1518
1519 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1520 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1521 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1522 default:
1523 WARN_ON_ONCE(1);
1524 }
1525 if (!ret)
1526 event_notifier->priv->parent.registered = 1;
1527 }
1528
1529 static
1530 int _lttng_event_notifier_unregister(
1531 struct lttng_kernel_event_notifier *event_notifier)
1532 {
1533 const struct lttng_kernel_event_desc *desc;
1534 int ret = -EINVAL;
1535
1536 if (!event_notifier->priv->parent.registered)
1537 return 0;
1538
1539 desc = event_notifier->priv->parent.desc;
1540 switch (event_notifier->priv->parent.instrumentation) {
1541 case LTTNG_KERNEL_ABI_TRACEPOINT:
1542 ret = lttng_wrapper_tracepoint_probe_unregister(event_notifier->priv->parent.desc->event_kname,
1543 event_notifier->priv->parent.desc->tp_class->probe_callback,
1544 event_notifier);
1545 break;
1546
1547 case LTTNG_KERNEL_ABI_KPROBE:
1548 lttng_kprobes_unregister_event_notifier(event_notifier);
1549 ret = 0;
1550 break;
1551
1552 case LTTNG_KERNEL_ABI_UPROBE:
1553 lttng_uprobes_unregister_event_notifier(event_notifier);
1554 ret = 0;
1555 break;
1556
1557 case LTTNG_KERNEL_ABI_SYSCALL:
1558 ret = lttng_syscall_filter_disable_event_notifier(event_notifier);
1559 break;
1560
1561 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1562 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1563 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1564 default:
1565 WARN_ON_ONCE(1);
1566 }
1567 if (!ret)
1568 event_notifier->priv->parent.registered = 0;
1569 return ret;
1570 }
1571
1572 /*
1573 * Only used internally at session destruction.
1574 */
1575 static
1576 void _lttng_event_destroy(struct lttng_kernel_event_common *event)
1577 {
1578 struct lttng_kernel_event_common_private *event_priv = event->priv;
1579 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1580
1581 lttng_free_event_filter_runtime(event);
1582 /* Free event enabler refs */
1583 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1584 &event_priv->enablers_ref_head, node)
1585 kfree(enabler_ref);
1586
1587 switch (event->type) {
1588 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1589 {
1590 struct lttng_kernel_event_recorder *event_recorder =
1591 container_of(event, struct lttng_kernel_event_recorder, parent);
1592
1593 switch (event_priv->instrumentation) {
1594 case LTTNG_KERNEL_ABI_TRACEPOINT:
1595 lttng_event_desc_put(event_priv->desc);
1596 break;
1597
1598 case LTTNG_KERNEL_ABI_KPROBE:
1599 module_put(event_priv->desc->owner);
1600 lttng_kprobes_destroy_event_private(event_recorder);
1601 break;
1602
1603 case LTTNG_KERNEL_ABI_KRETPROBE:
1604 module_put(event_priv->desc->owner);
1605 lttng_kretprobes_destroy_private(event_recorder);
1606 break;
1607
1608 case LTTNG_KERNEL_ABI_SYSCALL:
1609 break;
1610
1611 case LTTNG_KERNEL_ABI_UPROBE:
1612 module_put(event_priv->desc->owner);
1613 lttng_uprobes_destroy_event_private(event_recorder);
1614 break;
1615
1616 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1617 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1618 default:
1619 WARN_ON_ONCE(1);
1620 }
1621 list_del(&event_recorder->priv->node);
1622 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
1623 kmem_cache_free(event_recorder_cache, event_recorder);
1624 break;
1625 }
1626 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1627 {
1628 struct lttng_kernel_event_notifier *event_notifier =
1629 container_of(event, struct lttng_kernel_event_notifier, parent);
1630
1631 switch (event_notifier->priv->parent.instrumentation) {
1632 case LTTNG_KERNEL_ABI_TRACEPOINT:
1633 lttng_event_desc_put(event_notifier->priv->parent.desc);
1634 break;
1635
1636 case LTTNG_KERNEL_ABI_KPROBE:
1637 module_put(event_notifier->priv->parent.desc->owner);
1638 lttng_kprobes_destroy_event_notifier_private(event_notifier);
1639 break;
1640
1641 case LTTNG_KERNEL_ABI_SYSCALL:
1642 break;
1643
1644 case LTTNG_KERNEL_ABI_UPROBE:
1645 module_put(event_notifier->priv->parent.desc->owner);
1646 lttng_uprobes_destroy_event_notifier_private(event_notifier);
1647 break;
1648
1649 case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
1650 case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
1651 case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
1652 default:
1653 WARN_ON_ONCE(1);
1654 }
1655 list_del(&event_notifier->priv->node);
1656 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1657 kmem_cache_free(event_notifier_cache, event_notifier);
1658 break;
1659 }
1660 default:
1661 WARN_ON_ONCE(1);
1662 }
1663 }
1664
1665 struct lttng_kernel_id_tracker *get_tracker(struct lttng_kernel_session *session,
1666 enum tracker_type tracker_type)
1667 {
1668 switch (tracker_type) {
1669 case TRACKER_PID:
1670 return &session->pid_tracker;
1671 case TRACKER_VPID:
1672 return &session->vpid_tracker;
1673 case TRACKER_UID:
1674 return &session->uid_tracker;
1675 case TRACKER_VUID:
1676 return &session->vuid_tracker;
1677 case TRACKER_GID:
1678 return &session->gid_tracker;
1679 case TRACKER_VGID:
1680 return &session->vgid_tracker;
1681 default:
1682 WARN_ON_ONCE(1);
1683 return NULL;
1684 }
1685 }
1686
1687 int lttng_session_track_id(struct lttng_kernel_session *session,
1688 enum tracker_type tracker_type, int id)
1689 {
1690 struct lttng_kernel_id_tracker *tracker;
1691 int ret;
1692
1693 tracker = get_tracker(session, tracker_type);
1694 if (!tracker)
1695 return -EINVAL;
1696 if (id < -1)
1697 return -EINVAL;
1698 mutex_lock(&sessions_mutex);
1699 if (id == -1) {
1700 /* track all ids: destroy tracker. */
1701 lttng_id_tracker_destroy(tracker, true);
1702 ret = 0;
1703 } else {
1704 ret = lttng_id_tracker_add(tracker, id);
1705 }
1706 mutex_unlock(&sessions_mutex);
1707 return ret;
1708 }
1709
1710 int lttng_session_untrack_id(struct lttng_kernel_session *session,
1711 enum tracker_type tracker_type, int id)
1712 {
1713 struct lttng_kernel_id_tracker *tracker;
1714 int ret;
1715
1716 tracker = get_tracker(session, tracker_type);
1717 if (!tracker)
1718 return -EINVAL;
1719 if (id < -1)
1720 return -EINVAL;
1721 mutex_lock(&sessions_mutex);
1722 if (id == -1) {
1723 /* untrack all ids: replace by empty tracker. */
1724 ret = lttng_id_tracker_empty_set(tracker);
1725 } else {
1726 ret = lttng_id_tracker_del(tracker, id);
1727 }
1728 mutex_unlock(&sessions_mutex);
1729 return ret;
1730 }
1731
1732 static
1733 void *id_list_start(struct seq_file *m, loff_t *pos)
1734 {
1735 struct lttng_kernel_id_tracker *id_tracker = m->private;
1736 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1737 struct lttng_id_hash_node *e;
1738 int iter = 0, i;
1739
1740 mutex_lock(&sessions_mutex);
1741 if (id_tracker_p) {
1742 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1743 struct hlist_head *head = &id_tracker_p->id_hash[i];
1744
1745 lttng_hlist_for_each_entry(e, head, hlist) {
1746 if (iter++ >= *pos)
1747 return e;
1748 }
1749 }
1750 } else {
1751 /* ID tracker disabled. */
1752 if (iter >= *pos && iter == 0) {
1753 return id_tracker_p; /* empty tracker */
1754 }
1755 iter++;
1756 }
1757 /* End of list */
1758 return NULL;
1759 }
1760
1761 /* Called with sessions_mutex held. */
1762 static
1763 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1764 {
1765 struct lttng_kernel_id_tracker *id_tracker = m->private;
1766 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1767 struct lttng_id_hash_node *e;
1768 int iter = 0, i;
1769
1770 (*ppos)++;
1771 if (id_tracker_p) {
1772 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1773 struct hlist_head *head = &id_tracker_p->id_hash[i];
1774
1775 lttng_hlist_for_each_entry(e, head, hlist) {
1776 if (iter++ >= *ppos)
1777 return e;
1778 }
1779 }
1780 } else {
1781 /* ID tracker disabled. */
1782 if (iter >= *ppos && iter == 0)
1783 return p; /* empty tracker */
1784 iter++;
1785 }
1786
1787 /* End of list */
1788 return NULL;
1789 }
1790
1791 static
1792 void id_list_stop(struct seq_file *m, void *p)
1793 {
1794 mutex_unlock(&sessions_mutex);
1795 }
1796
1797 static
1798 int id_list_show(struct seq_file *m, void *p)
1799 {
1800 struct lttng_kernel_id_tracker *id_tracker = m->private;
1801 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1802 int id;
1803
1804 if (p == id_tracker_p) {
1805 /* Tracker disabled. */
1806 id = -1;
1807 } else {
1808 const struct lttng_id_hash_node *e = p;
1809
1810 id = lttng_id_tracker_get_node_id(e);
1811 }
1812 switch (id_tracker->priv->tracker_type) {
1813 case TRACKER_PID:
1814 seq_printf(m, "process { pid = %d; };\n", id);
1815 break;
1816 case TRACKER_VPID:
1817 seq_printf(m, "process { vpid = %d; };\n", id);
1818 break;
1819 case TRACKER_UID:
1820 seq_printf(m, "user { uid = %d; };\n", id);
1821 break;
1822 case TRACKER_VUID:
1823 seq_printf(m, "user { vuid = %d; };\n", id);
1824 break;
1825 case TRACKER_GID:
1826 seq_printf(m, "group { gid = %d; };\n", id);
1827 break;
1828 case TRACKER_VGID:
1829 seq_printf(m, "group { vgid = %d; };\n", id);
1830 break;
1831 default:
1832 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1833 }
1834 return 0;
1835 }
1836
1837 static
1838 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1839 .start = id_list_start,
1840 .next = id_list_next,
1841 .stop = id_list_stop,
1842 .show = id_list_show,
1843 };
1844
1845 static
1846 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1847 {
1848 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1849 }
1850
1851 static
1852 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1853 {
1854 struct seq_file *m = file->private_data;
1855 struct lttng_kernel_id_tracker *id_tracker = m->private;
1856 int ret;
1857
1858 WARN_ON_ONCE(!id_tracker);
1859 ret = seq_release(inode, file);
1860 if (!ret)
1861 fput(id_tracker->priv->session->priv->file);
1862 return ret;
1863 }
1864
1865 const struct file_operations lttng_tracker_ids_list_fops = {
1866 .owner = THIS_MODULE,
1867 .open = lttng_tracker_ids_list_open,
1868 .read = seq_read,
1869 .llseek = seq_lseek,
1870 .release = lttng_tracker_ids_list_release,
1871 };
1872
1873 int lttng_session_list_tracker_ids(struct lttng_kernel_session *session,
1874 enum tracker_type tracker_type)
1875 {
1876 struct file *tracker_ids_list_file;
1877 struct seq_file *m;
1878 int file_fd, ret;
1879
1880 file_fd = lttng_get_unused_fd();
1881 if (file_fd < 0) {
1882 ret = file_fd;
1883 goto fd_error;
1884 }
1885
1886 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1887 &lttng_tracker_ids_list_fops,
1888 NULL, O_RDWR);
1889 if (IS_ERR(tracker_ids_list_file)) {
1890 ret = PTR_ERR(tracker_ids_list_file);
1891 goto file_error;
1892 }
1893 if (!atomic_long_add_unless(&session->priv->file->f_count, 1, LONG_MAX)) {
1894 ret = -EOVERFLOW;
1895 goto refcount_error;
1896 }
1897 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1898 if (ret < 0)
1899 goto open_error;
1900 m = tracker_ids_list_file->private_data;
1901
1902 m->private = get_tracker(session, tracker_type);
1903 BUG_ON(!m->private);
1904 fd_install(file_fd, tracker_ids_list_file);
1905
1906 return file_fd;
1907
1908 open_error:
1909 atomic_long_dec(&session->priv->file->f_count);
1910 refcount_error:
1911 fput(tracker_ids_list_file);
1912 file_error:
1913 put_unused_fd(file_fd);
1914 fd_error:
1915 return ret;
1916 }
1917
1918 /*
1919 * Enabler management.
1920 */
1921 static
1922 int lttng_match_enabler_star_glob(const char *desc_name,
1923 const char *pattern)
1924 {
1925 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1926 desc_name, LTTNG_SIZE_MAX))
1927 return 0;
1928 return 1;
1929 }
1930
1931 static
1932 int lttng_match_enabler_name(const char *desc_name,
1933 const char *name)
1934 {
1935 if (strcmp(desc_name, name))
1936 return 0;
1937 return 1;
1938 }
1939
1940 int lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
1941 struct lttng_enabler *enabler)
1942 {
1943 const char *desc_name, *enabler_name;
1944 bool compat = false, entry = false;
1945
1946 enabler_name = enabler->event_param.name;
1947 switch (enabler->event_param.instrumentation) {
1948 case LTTNG_KERNEL_ABI_TRACEPOINT:
1949 desc_name = desc->event_name;
1950 switch (enabler->format_type) {
1951 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1952 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1953 case LTTNG_ENABLER_FORMAT_NAME:
1954 return lttng_match_enabler_name(desc_name, enabler_name);
1955 default:
1956 return -EINVAL;
1957 }
1958 break;
1959
1960 case LTTNG_KERNEL_ABI_SYSCALL:
1961 desc_name = desc->event_name;
1962 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1963 desc_name += strlen("compat_");
1964 compat = true;
1965 }
1966 if (!strncmp(desc_name, "syscall_exit_",
1967 strlen("syscall_exit_"))) {
1968 desc_name += strlen("syscall_exit_");
1969 } else if (!strncmp(desc_name, "syscall_entry_",
1970 strlen("syscall_entry_"))) {
1971 desc_name += strlen("syscall_entry_");
1972 entry = true;
1973 } else {
1974 WARN_ON_ONCE(1);
1975 return -EINVAL;
1976 }
1977 switch (enabler->event_param.u.syscall.entryexit) {
1978 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1979 break;
1980 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1981 if (!entry)
1982 return 0;
1983 break;
1984 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1985 if (entry)
1986 return 0;
1987 break;
1988 default:
1989 return -EINVAL;
1990 }
1991 switch (enabler->event_param.u.syscall.abi) {
1992 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1993 break;
1994 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1995 if (compat)
1996 return 0;
1997 break;
1998 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1999 if (!compat)
2000 return 0;
2001 break;
2002 default:
2003 return -EINVAL;
2004 }
2005 switch (enabler->event_param.u.syscall.match) {
2006 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
2007 switch (enabler->format_type) {
2008 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2009 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2010 case LTTNG_ENABLER_FORMAT_NAME:
2011 return lttng_match_enabler_name(desc_name, enabler_name);
2012 default:
2013 return -EINVAL;
2014 }
2015 break;
2016 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
2017 return -EINVAL; /* Not implemented. */
2018 default:
2019 return -EINVAL;
2020 }
2021 break;
2022
2023 default:
2024 WARN_ON_ONCE(1);
2025 return -EINVAL;
2026 }
2027 }
2028
2029 static
2030 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
2031 struct lttng_kernel_event_recorder *event_recorder)
2032 {
2033 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
2034 event_enabler);
2035
2036 if (base_enabler->event_param.instrumentation != event_recorder->priv->parent.instrumentation)
2037 return 0;
2038 if (lttng_desc_match_enabler(event_recorder->priv->parent.desc, base_enabler)
2039 && event_recorder->chan == event_enabler->chan)
2040 return 1;
2041 else
2042 return 0;
2043 }
2044
2045 static
2046 int lttng_event_notifier_enabler_match_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler,
2047 struct lttng_kernel_event_notifier *event_notifier)
2048 {
2049 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(
2050 event_notifier_enabler);
2051
2052 if (base_enabler->event_param.instrumentation != event_notifier->priv->parent.instrumentation)
2053 return 0;
2054 if (lttng_desc_match_enabler(event_notifier->priv->parent.desc, base_enabler)
2055 && event_notifier->priv->group == event_notifier_enabler->group
2056 && event_notifier->priv->parent.user_token == event_notifier_enabler->base.user_token)
2057 return 1;
2058 else
2059 return 0;
2060 }
2061
2062 static
2063 struct lttng_enabler_ref *lttng_enabler_ref(
2064 struct list_head *enablers_ref_list,
2065 struct lttng_enabler *enabler)
2066 {
2067 struct lttng_enabler_ref *enabler_ref;
2068
2069 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2070 if (enabler_ref->ref == enabler)
2071 return enabler_ref;
2072 }
2073 return NULL;
2074 }
2075
2076 static
2077 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
2078 {
2079 struct lttng_kernel_session *session = event_enabler->chan->parent.session;
2080 struct lttng_kernel_probe_desc *probe_desc;
2081 const struct lttng_kernel_event_desc *desc;
2082 int i;
2083 struct list_head *probe_list;
2084
2085 probe_list = lttng_get_probe_list_head();
2086 /*
2087 * For each probe event, if we find that a probe event matches
2088 * our enabler, create an associated lttng_event if not
2089 * already present.
2090 */
2091 list_for_each_entry(probe_desc, probe_list, head) {
2092 for (i = 0; i < probe_desc->nr_events; i++) {
2093 int found = 0;
2094 struct hlist_head *head;
2095 struct lttng_kernel_event_recorder_private *event_recorder_private;
2096 struct lttng_kernel_event_recorder *event_recorder;
2097
2098 desc = probe_desc->event_desc[i];
2099 if (!lttng_desc_match_enabler(desc,
2100 lttng_event_enabler_as_enabler(event_enabler)))
2101 continue;
2102
2103 /*
2104 * Check if already created.
2105 */
2106 head = utils_borrow_hash_table_bucket(
2107 session->priv->events_ht.table, LTTNG_EVENT_HT_SIZE,
2108 desc->event_name);
2109 lttng_hlist_for_each_entry(event_recorder_private, head, hlist) {
2110 if (event_recorder_private->parent.desc == desc
2111 && event_recorder_private->pub->chan == event_enabler->chan)
2112 found = 1;
2113 }
2114 if (found)
2115 continue;
2116
2117 /*
2118 * We need to create an event for this
2119 * event probe.
2120 */
2121 event_recorder = _lttng_kernel_event_recorder_create(event_enabler->chan,
2122 NULL, desc, LTTNG_KERNEL_ABI_TRACEPOINT);
2123 if (!event_recorder) {
2124 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2125 probe_desc->event_desc[i]->event_name);
2126 }
2127 }
2128 }
2129 }
2130
2131 static
2132 void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2133 {
2134 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2135 struct lttng_kernel_probe_desc *probe_desc;
2136 const struct lttng_kernel_event_desc *desc;
2137 int i;
2138 struct list_head *probe_list;
2139
2140 probe_list = lttng_get_probe_list_head();
2141 /*
2142 * For each probe event, if we find that a probe event matches
2143 * our enabler, create an associated lttng_event_notifier if not
2144 * already present.
2145 */
2146 list_for_each_entry(probe_desc, probe_list, head) {
2147 for (i = 0; i < probe_desc->nr_events; i++) {
2148 int found = 0;
2149 struct hlist_head *head;
2150 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2151 struct lttng_kernel_event_notifier *event_notifier;
2152
2153 desc = probe_desc->event_desc[i];
2154 if (!lttng_desc_match_enabler(desc,
2155 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
2156 continue;
2157
2158 /*
2159 * Check if already created.
2160 */
2161 head = utils_borrow_hash_table_bucket(
2162 event_notifier_group->event_notifiers_ht.table,
2163 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->event_name);
2164 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
2165 if (event_notifier_priv->parent.desc == desc
2166 && event_notifier_priv->parent.user_token == event_notifier_enabler->base.user_token)
2167 found = 1;
2168 }
2169 if (found)
2170 continue;
2171
2172 /*
2173 * We need to create a event_notifier for this event probe.
2174 */
2175 event_notifier = _lttng_event_notifier_create(desc,
2176 event_notifier_enabler->base.user_token,
2177 event_notifier_enabler->error_counter_index,
2178 event_notifier_group, NULL,
2179 LTTNG_KERNEL_ABI_TRACEPOINT);
2180 if (IS_ERR(event_notifier)) {
2181 printk(KERN_INFO "Unable to create event_notifier %s\n",
2182 probe_desc->event_desc[i]->event_name);
2183 }
2184 }
2185 }
2186 }
2187
2188 static
2189 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
2190 {
2191 int ret;
2192
2193 ret = lttng_syscalls_register_event(event_enabler);
2194 WARN_ON_ONCE(ret);
2195 }
2196
2197 static
2198 void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2199 {
2200 int ret;
2201
2202 ret = lttng_syscalls_register_event_notifier(event_notifier_enabler);
2203 WARN_ON_ONCE(ret);
2204 ret = lttng_syscalls_create_matching_event_notifiers(event_notifier_enabler);
2205 WARN_ON_ONCE(ret);
2206 }
2207
2208 /*
2209 * Create struct lttng_kernel_event_recorder if it is missing and present in the list of
2210 * tracepoint probes.
2211 * Should be called with sessions mutex held.
2212 */
2213 static
2214 void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
2215 {
2216 switch (event_enabler->base.event_param.instrumentation) {
2217 case LTTNG_KERNEL_ABI_TRACEPOINT:
2218 lttng_create_tracepoint_event_if_missing(event_enabler);
2219 break;
2220
2221 case LTTNG_KERNEL_ABI_SYSCALL:
2222 lttng_create_syscall_event_if_missing(event_enabler);
2223 break;
2224
2225 default:
2226 WARN_ON_ONCE(1);
2227 break;
2228 }
2229 }
2230
2231 /*
2232 * Create events associated with an event_enabler (if not already present),
2233 * and add backward reference from the event to the enabler.
2234 * Should be called with sessions mutex held.
2235 */
2236 static
2237 int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
2238 {
2239 struct lttng_kernel_channel_buffer *chan = event_enabler->chan;
2240 struct lttng_kernel_session *session = event_enabler->chan->parent.session;
2241 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
2242 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2243
2244 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2245 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2246 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2247 !strcmp(base_enabler->event_param.name, "*")) {
2248 int enabled = base_enabler->enabled;
2249 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2250
2251 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2252 WRITE_ONCE(chan->priv->parent.syscall_all_entry, enabled);
2253
2254 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2255 WRITE_ONCE(chan->priv->parent.syscall_all_exit, enabled);
2256 }
2257
2258 /* First ensure that probe events are created for this enabler. */
2259 lttng_create_event_if_missing(event_enabler);
2260
2261 /* For each event matching event_enabler in session event list. */
2262 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
2263 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2264 struct lttng_enabler_ref *enabler_ref;
2265
2266 if (!lttng_event_enabler_match_event(event_enabler, event_recorder))
2267 continue;
2268 enabler_ref = lttng_enabler_ref(&event_recorder_priv->parent.enablers_ref_head,
2269 lttng_event_enabler_as_enabler(event_enabler));
2270 if (!enabler_ref) {
2271 /*
2272 * If no backward ref, create it.
2273 * Add backward ref from event to event_enabler.
2274 */
2275 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2276 if (!enabler_ref)
2277 return -ENOMEM;
2278 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
2279 list_add(&enabler_ref->node,
2280 &event_recorder_priv->parent.enablers_ref_head);
2281 }
2282
2283 /*
2284 * Link filter bytecodes if not linked yet.
2285 */
2286 lttng_enabler_link_bytecode(event_recorder_priv->parent.desc,
2287 lttng_static_ctx,
2288 &event_recorder_priv->parent.filter_bytecode_runtime_head,
2289 &lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
2290 }
2291 return 0;
2292 }
2293
2294 /*
2295 * Create struct lttng_kernel_event_notifier if it is missing and present in the list of
2296 * tracepoint probes.
2297 * Should be called with sessions mutex held.
2298 */
2299 static
2300 void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2301 {
2302 switch (event_notifier_enabler->base.event_param.instrumentation) {
2303 case LTTNG_KERNEL_ABI_TRACEPOINT:
2304 lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
2305 break;
2306
2307 case LTTNG_KERNEL_ABI_SYSCALL:
2308 lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler);
2309 break;
2310
2311 default:
2312 WARN_ON_ONCE(1);
2313 break;
2314 }
2315 }
2316
2317 /*
2318 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2319 */
2320 static
2321 int lttng_event_notifier_enabler_ref_event_notifiers(
2322 struct lttng_event_notifier_enabler *event_notifier_enabler)
2323 {
2324 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2325 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2326 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2327
2328 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2329 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2330 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2331 !strcmp(base_enabler->event_param.name, "*")) {
2332
2333 int enabled = base_enabler->enabled;
2334 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2335
2336 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2337 WRITE_ONCE(event_notifier_group->syscall_all_entry, enabled);
2338
2339 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2340 WRITE_ONCE(event_notifier_group->syscall_all_exit, enabled);
2341
2342 }
2343
2344 /* First ensure that probe event_notifiers are created for this enabler. */
2345 lttng_create_event_notifier_if_missing(event_notifier_enabler);
2346
2347 /* Link the created event_notifier with its associated enabler. */
2348 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2349 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2350 struct lttng_enabler_ref *enabler_ref;
2351
2352 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier))
2353 continue;
2354
2355 enabler_ref = lttng_enabler_ref(&event_notifier_priv->parent.enablers_ref_head,
2356 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2357 if (!enabler_ref) {
2358 /*
2359 * If no backward ref, create it.
2360 * Add backward ref from event_notifier to enabler.
2361 */
2362 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2363 if (!enabler_ref)
2364 return -ENOMEM;
2365
2366 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2367 event_notifier_enabler);
2368 list_add(&enabler_ref->node,
2369 &event_notifier_priv->parent.enablers_ref_head);
2370 }
2371
2372 /*
2373 * Link filter bytecodes if not linked yet.
2374 */
2375 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2376 lttng_static_ctx, &event_notifier_priv->parent.filter_bytecode_runtime_head,
2377 &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
2378
2379 /* Link capture bytecodes if not linked yet. */
2380 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2381 lttng_static_ctx, &event_notifier_priv->capture_bytecode_runtime_head,
2382 &event_notifier_enabler->capture_bytecode_head);
2383
2384 event_notifier_priv->num_captures = event_notifier_enabler->num_captures;
2385 }
2386 return 0;
2387 }
2388
2389 /*
2390 * Called at module load: connect the probe on all enablers matching
2391 * this event.
2392 * Called with sessions lock held.
2393 */
2394 int lttng_fix_pending_events(void)
2395 {
2396 struct lttng_kernel_session_private *session_priv;
2397
2398 list_for_each_entry(session_priv, &sessions, list)
2399 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2400 return 0;
2401 }
2402
2403 static bool lttng_event_notifier_group_has_active_event_notifiers(
2404 struct lttng_event_notifier_group *event_notifier_group)
2405 {
2406 struct lttng_event_notifier_enabler *event_notifier_enabler;
2407
2408 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2409 node) {
2410 if (event_notifier_enabler->base.enabled)
2411 return true;
2412 }
2413 return false;
2414 }
2415
2416 bool lttng_event_notifier_active(void)
2417 {
2418 struct lttng_event_notifier_group *event_notifier_group;
2419
2420 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2421 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2422 return true;
2423 }
2424 return false;
2425 }
2426
2427 int lttng_fix_pending_event_notifiers(void)
2428 {
2429 struct lttng_event_notifier_group *event_notifier_group;
2430
2431 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2432 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2433 return 0;
2434 }
2435
2436 struct lttng_event_enabler *lttng_event_enabler_create(
2437 enum lttng_enabler_format_type format_type,
2438 struct lttng_kernel_abi_event *event_param,
2439 struct lttng_kernel_channel_buffer *chan)
2440 {
2441 struct lttng_event_enabler *event_enabler;
2442
2443 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2444 if (!event_enabler)
2445 return NULL;
2446 event_enabler->base.format_type = format_type;
2447 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2448 memcpy(&event_enabler->base.event_param, event_param,
2449 sizeof(event_enabler->base.event_param));
2450 event_enabler->chan = chan;
2451 /* ctx left NULL */
2452 event_enabler->base.enabled = 0;
2453 mutex_lock(&sessions_mutex);
2454 list_add(&event_enabler->node, &event_enabler->chan->parent.session->priv->enablers_head);
2455 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2456 mutex_unlock(&sessions_mutex);
2457 return event_enabler;
2458 }
2459
2460 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2461 {
2462 mutex_lock(&sessions_mutex);
2463 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2464 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2465 mutex_unlock(&sessions_mutex);
2466 return 0;
2467 }
2468
2469 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2470 {
2471 mutex_lock(&sessions_mutex);
2472 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2473 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2474 mutex_unlock(&sessions_mutex);
2475 return 0;
2476 }
2477
2478 static
2479 int lttng_enabler_attach_filter_bytecode(struct lttng_enabler *enabler,
2480 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2481 {
2482 struct lttng_kernel_bytecode_node *bytecode_node;
2483 uint32_t bytecode_len;
2484 int ret;
2485
2486 ret = get_user(bytecode_len, &bytecode->len);
2487 if (ret)
2488 return ret;
2489 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2490 GFP_KERNEL);
2491 if (!bytecode_node)
2492 return -ENOMEM;
2493 ret = copy_from_user(&bytecode_node->bc, bytecode,
2494 sizeof(*bytecode) + bytecode_len);
2495 if (ret)
2496 goto error_free;
2497
2498 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2499 bytecode_node->enabler = enabler;
2500 /* Enforce length based on allocated size */
2501 bytecode_node->bc.len = bytecode_len;
2502 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2503
2504 return 0;
2505
2506 error_free:
2507 lttng_kvfree(bytecode_node);
2508 return ret;
2509 }
2510
2511 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler *event_enabler,
2512 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2513 {
2514 int ret;
2515 ret = lttng_enabler_attach_filter_bytecode(
2516 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2517 if (ret)
2518 goto error;
2519
2520 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2521 return 0;
2522
2523 error:
2524 return ret;
2525 }
2526
2527 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2528 struct lttng_kernel_abi_event_callsite __user *callsite)
2529 {
2530
2531 switch (event->priv->instrumentation) {
2532 case LTTNG_KERNEL_ABI_UPROBE:
2533 return lttng_uprobes_event_add_callsite(event, callsite);
2534 default:
2535 return -EINVAL;
2536 }
2537 }
2538
2539 static
2540 void lttng_enabler_destroy(struct lttng_enabler *enabler)
2541 {
2542 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2543
2544 /* Destroy filter bytecode */
2545 list_for_each_entry_safe(filter_node, tmp_filter_node,
2546 &enabler->filter_bytecode_head, node) {
2547 lttng_kvfree(filter_node);
2548 }
2549 }
2550
2551 static
2552 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2553 {
2554 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2555
2556 list_del(&event_enabler->node);
2557 kfree(event_enabler);
2558 }
2559
2560 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2561 struct lttng_event_notifier_group *event_notifier_group,
2562 enum lttng_enabler_format_type format_type,
2563 struct lttng_kernel_abi_event_notifier *event_notifier_param)
2564 {
2565 struct lttng_event_notifier_enabler *event_notifier_enabler;
2566
2567 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2568 if (!event_notifier_enabler)
2569 return NULL;
2570
2571 event_notifier_enabler->base.format_type = format_type;
2572 INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
2573 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2574
2575 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2576 event_notifier_enabler->num_captures = 0;
2577
2578 memcpy(&event_notifier_enabler->base.event_param, &event_notifier_param->event,
2579 sizeof(event_notifier_enabler->base.event_param));
2580
2581 event_notifier_enabler->base.enabled = 0;
2582 event_notifier_enabler->base.user_token = event_notifier_param->event.token;
2583 event_notifier_enabler->group = event_notifier_group;
2584
2585 mutex_lock(&sessions_mutex);
2586 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2587 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2588
2589 mutex_unlock(&sessions_mutex);
2590
2591 return event_notifier_enabler;
2592 }
2593
2594 int lttng_event_notifier_enabler_enable(
2595 struct lttng_event_notifier_enabler *event_notifier_enabler)
2596 {
2597 mutex_lock(&sessions_mutex);
2598 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2599 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2600 mutex_unlock(&sessions_mutex);
2601 return 0;
2602 }
2603
2604 int lttng_event_notifier_enabler_disable(
2605 struct lttng_event_notifier_enabler *event_notifier_enabler)
2606 {
2607 mutex_lock(&sessions_mutex);
2608 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2609 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2610 mutex_unlock(&sessions_mutex);
2611 return 0;
2612 }
2613
2614 int lttng_event_notifier_enabler_attach_filter_bytecode(
2615 struct lttng_event_notifier_enabler *event_notifier_enabler,
2616 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2617 {
2618 int ret;
2619
2620 ret = lttng_enabler_attach_filter_bytecode(
2621 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
2622 bytecode);
2623 if (ret)
2624 goto error;
2625
2626 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2627 return 0;
2628
2629 error:
2630 return ret;
2631 }
2632
2633 int lttng_event_notifier_enabler_attach_capture_bytecode(
2634 struct lttng_event_notifier_enabler *event_notifier_enabler,
2635 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2636 {
2637 struct lttng_kernel_bytecode_node *bytecode_node;
2638 struct lttng_enabler *enabler =
2639 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2640 uint32_t bytecode_len;
2641 int ret;
2642
2643 ret = get_user(bytecode_len, &bytecode->len);
2644 if (ret)
2645 return ret;
2646
2647 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2648 GFP_KERNEL);
2649 if (!bytecode_node)
2650 return -ENOMEM;
2651
2652 ret = copy_from_user(&bytecode_node->bc, bytecode,
2653 sizeof(*bytecode) + bytecode_len);
2654 if (ret)
2655 goto error_free;
2656
2657 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2658 bytecode_node->enabler = enabler;
2659
2660 /* Enforce length based on allocated size */
2661 bytecode_node->bc.len = bytecode_len;
2662 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2663
2664 event_notifier_enabler->num_captures++;
2665
2666 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2667 goto end;
2668
2669 error_free:
2670 lttng_kvfree(bytecode_node);
2671 end:
2672 return ret;
2673 }
2674
2675 static
2676 void lttng_event_notifier_enabler_destroy(
2677 struct lttng_event_notifier_enabler *event_notifier_enabler)
2678 {
2679 if (!event_notifier_enabler) {
2680 return;
2681 }
2682
2683 list_del(&event_notifier_enabler->node);
2684
2685 lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2686 kfree(event_notifier_enabler);
2687 }
2688
2689 /*
2690 * lttng_session_sync_event_enablers should be called just before starting a
2691 * session.
2692 * Should be called with sessions mutex held.
2693 */
2694 static
2695 void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2696 {
2697 struct lttng_event_enabler *event_enabler;
2698 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2699
2700 list_for_each_entry(event_enabler, &session->priv->enablers_head, node)
2701 lttng_event_enabler_ref_events(event_enabler);
2702 /*
2703 * For each event, if at least one of its enablers is enabled,
2704 * and its channel and session transient states are enabled, we
2705 * enable the event, else we disable it.
2706 */
2707 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
2708 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2709 struct lttng_enabler_ref *enabler_ref;
2710 struct lttng_kernel_bytecode_runtime *runtime;
2711 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2712 int nr_filters = 0;
2713
2714 switch (event_recorder_priv->parent.instrumentation) {
2715 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
2716 case LTTNG_KERNEL_ABI_SYSCALL:
2717 /* Enable events */
2718 list_for_each_entry(enabler_ref,
2719 &event_recorder_priv->parent.enablers_ref_head, node) {
2720 if (enabler_ref->ref->enabled) {
2721 enabled = 1;
2722 break;
2723 }
2724 }
2725 break;
2726
2727 default:
2728 /* Not handled with lazy sync. */
2729 continue;
2730 }
2731 /*
2732 * Enabled state is based on union of enablers, with
2733 * intesection of session and channel transient enable
2734 * states.
2735 */
2736 enabled = enabled && session->priv->tstate && event_recorder->chan->priv->parent.tstate;
2737
2738 WRITE_ONCE(event_recorder->parent.enabled, enabled);
2739 /*
2740 * Sync tracepoint registration with event enabled
2741 * state.
2742 */
2743 if (enabled) {
2744 register_event(event_recorder);
2745 } else {
2746 _lttng_event_unregister(event_recorder);
2747 }
2748
2749 /* Check if has enablers without bytecode enabled */
2750 list_for_each_entry(enabler_ref,
2751 &event_recorder_priv->parent.enablers_ref_head, node) {
2752 if (enabler_ref->ref->enabled
2753 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2754 has_enablers_without_filter_bytecode = 1;
2755 break;
2756 }
2757 }
2758 event_recorder_priv->parent.has_enablers_without_filter_bytecode =
2759 has_enablers_without_filter_bytecode;
2760
2761 /* Enable filters */
2762 list_for_each_entry(runtime,
2763 &event_recorder_priv->parent.filter_bytecode_runtime_head, node) {
2764 lttng_bytecode_sync_state(runtime);
2765 nr_filters++;
2766 }
2767 WRITE_ONCE(event_recorder_priv->parent.pub->eval_filter,
2768 !(has_enablers_without_filter_bytecode || !nr_filters));
2769 }
2770 }
2771
2772 /*
2773 * Apply enablers to session events, adding events to session if need
2774 * be. It is required after each modification applied to an active
2775 * session, and right before session "start".
2776 * "lazy" sync means we only sync if required.
2777 * Should be called with sessions mutex held.
2778 */
2779 static
2780 void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2781 {
2782 /* We can skip if session is not active */
2783 if (!session->active)
2784 return;
2785 lttng_session_sync_event_enablers(session);
2786 }
2787
2788 static
2789 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2790 {
2791 struct lttng_event_notifier_enabler *event_notifier_enabler;
2792 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2793
2794 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2795 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2796
2797 /*
2798 * For each event_notifier, if at least one of its enablers is enabled,
2799 * we enable the event_notifier, else we disable it.
2800 */
2801 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2802 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2803 struct lttng_enabler_ref *enabler_ref;
2804 struct lttng_kernel_bytecode_runtime *runtime;
2805 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2806 int nr_filters = 0, nr_captures = 0;
2807
2808 switch (event_notifier_priv->parent.instrumentation) {
2809 case LTTNG_KERNEL_ABI_TRACEPOINT: /* Fall-through */
2810 case LTTNG_KERNEL_ABI_SYSCALL:
2811 /* Enable event_notifiers */
2812 list_for_each_entry(enabler_ref,
2813 &event_notifier_priv->parent.enablers_ref_head, node) {
2814 if (enabler_ref->ref->enabled) {
2815 enabled = 1;
2816 break;
2817 }
2818 }
2819 break;
2820
2821 default:
2822 /* Not handled with sync. */
2823 continue;
2824 }
2825
2826 WRITE_ONCE(event_notifier->parent.enabled, enabled);
2827 /*
2828 * Sync tracepoint registration with event_notifier enabled
2829 * state.
2830 */
2831 if (enabled) {
2832 if (!event_notifier_priv->parent.registered)
2833 register_event_notifier(event_notifier);
2834 } else {
2835 if (event_notifier_priv->parent.registered)
2836 _lttng_event_notifier_unregister(event_notifier);
2837 }
2838
2839 /* Check if has enablers without bytecode enabled */
2840 list_for_each_entry(enabler_ref,
2841 &event_notifier_priv->parent.enablers_ref_head, node) {
2842 if (enabler_ref->ref->enabled
2843 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2844 has_enablers_without_filter_bytecode = 1;
2845 break;
2846 }
2847 }
2848 event_notifier_priv->parent.has_enablers_without_filter_bytecode =
2849 has_enablers_without_filter_bytecode;
2850
2851 /* Enable filters */
2852 list_for_each_entry(runtime,
2853 &event_notifier_priv->parent.filter_bytecode_runtime_head, node) {
2854 lttng_bytecode_sync_state(runtime);
2855 nr_filters++;
2856 }
2857 WRITE_ONCE(event_notifier_priv->parent.pub->eval_filter,
2858 !(has_enablers_without_filter_bytecode || !nr_filters));
2859
2860 /* Enable captures */
2861 list_for_each_entry(runtime,
2862 &event_notifier_priv->capture_bytecode_runtime_head, node) {
2863 lttng_bytecode_sync_state(runtime);
2864 nr_captures++;
2865 }
2866 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2867 }
2868 }
2869
2870 /*
2871 * Serialize at most one packet worth of metadata into a metadata
2872 * channel.
2873 * We grab the metadata cache mutex to get exclusive access to our metadata
2874 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2875 * allows us to do racy operations such as looking for remaining space left in
2876 * packet and write, since mutual exclusion protects us from concurrent writes.
2877 * Mutual exclusion on the metadata cache allow us to read the cache content
2878 * without racing against reallocation of the cache by updates.
2879 * Returns the number of bytes written in the channel, 0 if no data
2880 * was written and a negative value on error.
2881 */
2882 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2883 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2884 {
2885 struct lttng_kernel_ring_buffer_ctx ctx;
2886 int ret = 0;
2887 size_t len, reserve_len;
2888
2889 /*
2890 * Ensure we support mutiple get_next / put sequences followed by
2891 * put_next. The metadata cache lock protects reading the metadata
2892 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2893 * "flush" operations on the buffer invoked by different processes.
2894 * Moreover, since the metadata cache memory can be reallocated, we
2895 * need to have exclusive access against updates even though we only
2896 * read it.
2897 */
2898 mutex_lock(&stream->metadata_cache->lock);
2899 WARN_ON(stream->metadata_in < stream->metadata_out);
2900 if (stream->metadata_in != stream->metadata_out)
2901 goto end;
2902
2903 /* Metadata regenerated, change the version. */
2904 if (stream->metadata_cache->version != stream->version)
2905 stream->version = stream->metadata_cache->version;
2906
2907 len = stream->metadata_cache->metadata_written -
2908 stream->metadata_in;
2909 if (!len)
2910 goto end;
2911 reserve_len = min_t(size_t,
2912 stream->transport->ops.priv->packet_avail_size(chan),
2913 len);
2914 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2915 sizeof(char), NULL);
2916 /*
2917 * If reservation failed, return an error to the caller.
2918 */
2919 ret = stream->transport->ops.event_reserve(&ctx);
2920 if (ret != 0) {
2921 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2922 stream->coherent = false;
2923 goto end;
2924 }
2925 stream->transport->ops.event_write(&ctx,
2926 stream->metadata_cache->data + stream->metadata_in,
2927 reserve_len);
2928 stream->transport->ops.event_commit(&ctx);
2929 stream->metadata_in += reserve_len;
2930 if (reserve_len < len)
2931 stream->coherent = false;
2932 else
2933 stream->coherent = true;
2934 ret = reserve_len;
2935
2936 end:
2937 if (coherent)
2938 *coherent = stream->coherent;
2939 mutex_unlock(&stream->metadata_cache->lock);
2940 return ret;
2941 }
2942
2943 static
2944 void lttng_metadata_begin(struct lttng_kernel_session *session)
2945 {
2946 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
2947 mutex_lock(&session->priv->metadata_cache->lock);
2948 }
2949
2950 static
2951 void lttng_metadata_end(struct lttng_kernel_session *session)
2952 {
2953 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2954 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
2955 struct lttng_metadata_stream *stream;
2956
2957 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
2958 wake_up_interruptible(&stream->read_wait);
2959 mutex_unlock(&session->priv->metadata_cache->lock);
2960 }
2961 }
2962
2963 /*
2964 * Write the metadata to the metadata cache.
2965 * Must be called with sessions_mutex held.
2966 * The metadata cache lock protects us from concurrent read access from
2967 * thread outputting metadata content to ring buffer.
2968 * The content of the printf is printed as a single atomic metadata
2969 * transaction.
2970 */
2971 int lttng_metadata_printf(struct lttng_kernel_session *session,
2972 const char *fmt, ...)
2973 {
2974 char *str;
2975 size_t len;
2976 va_list ap;
2977
2978 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2979
2980 va_start(ap, fmt);
2981 str = kvasprintf(GFP_KERNEL, fmt, ap);
2982 va_end(ap);
2983 if (!str)
2984 return -ENOMEM;
2985
2986 len = strlen(str);
2987 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2988 if (session->priv->metadata_cache->metadata_written + len >
2989 session->priv->metadata_cache->cache_alloc) {
2990 char *tmp_cache_realloc;
2991 unsigned int tmp_cache_alloc_size;
2992
2993 tmp_cache_alloc_size = max_t(unsigned int,
2994 session->priv->metadata_cache->cache_alloc + len,
2995 session->priv->metadata_cache->cache_alloc << 1);
2996 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2997 if (!tmp_cache_realloc)
2998 goto err;
2999 if (session->priv->metadata_cache->data) {
3000 memcpy(tmp_cache_realloc,
3001 session->priv->metadata_cache->data,
3002 session->priv->metadata_cache->cache_alloc);
3003 vfree(session->priv->metadata_cache->data);
3004 }
3005
3006 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
3007 session->priv->metadata_cache->data = tmp_cache_realloc;
3008 }
3009 memcpy(session->priv->metadata_cache->data +
3010 session->priv->metadata_cache->metadata_written,
3011 str, len);
3012 session->priv->metadata_cache->metadata_written += len;
3013 kfree(str);
3014
3015 return 0;
3016
3017 err:
3018 kfree(str);
3019 return -ENOMEM;
3020 }
3021
3022 static
3023 int print_tabs(struct lttng_kernel_session *session, size_t nesting)
3024 {
3025 size_t i;
3026
3027 for (i = 0; i < nesting; i++) {
3028 int ret;
3029
3030 ret = lttng_metadata_printf(session, " ");
3031 if (ret) {
3032 return ret;
3033 }
3034 }
3035 return 0;
3036 }
3037
3038 static
3039 int lttng_field_name_statedump(struct lttng_kernel_session *session,
3040 const struct lttng_kernel_event_field *field,
3041 size_t nesting)
3042 {
3043 return lttng_metadata_printf(session, " _%s;\n", field->name);
3044 }
3045
3046 static
3047 int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
3048 const struct lttng_kernel_type_integer *type,
3049 enum lttng_kernel_string_encoding parent_encoding,
3050 size_t nesting)
3051 {
3052 int ret;
3053
3054 ret = print_tabs(session, nesting);
3055 if (ret)
3056 return ret;
3057 ret = lttng_metadata_printf(session,
3058 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
3059 type->size,
3060 type->alignment,
3061 type->signedness,
3062 (parent_encoding == lttng_kernel_string_encoding_none)
3063 ? "none"
3064 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
3065 ? "UTF8"
3066 : "ASCII",
3067 type->base,
3068 #if __BYTE_ORDER == __BIG_ENDIAN
3069 type->reverse_byte_order ? " byte_order = le;" : ""
3070 #else
3071 type->reverse_byte_order ? " byte_order = be;" : ""
3072 #endif
3073 );
3074 return ret;
3075 }
3076
3077 /*
3078 * Must be called with sessions_mutex held.
3079 */
3080 static
3081 int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
3082 const struct lttng_kernel_type_struct *type,
3083 size_t nesting)
3084 {
3085 const char *prev_field_name = NULL;
3086 int ret;
3087 uint32_t i, nr_fields;
3088 unsigned int alignment;
3089
3090 ret = print_tabs(session, nesting);
3091 if (ret)
3092 return ret;
3093 ret = lttng_metadata_printf(session,
3094 "struct {\n");
3095 if (ret)
3096 return ret;
3097 nr_fields = type->nr_fields;
3098 for (i = 0; i < nr_fields; i++) {
3099 const struct lttng_kernel_event_field *iter_field;
3100
3101 iter_field = type->fields[i];
3102 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
3103 if (ret)
3104 return ret;
3105 }
3106 ret = print_tabs(session, nesting);
3107 if (ret)
3108 return ret;
3109 alignment = type->alignment;
3110 if (alignment) {
3111 ret = lttng_metadata_printf(session,
3112 "} align(%u)",
3113 alignment);
3114 } else {
3115 ret = lttng_metadata_printf(session,
3116 "}");
3117 }
3118 return ret;
3119 }
3120
3121 /*
3122 * Must be called with sessions_mutex held.
3123 */
3124 static
3125 int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
3126 const struct lttng_kernel_event_field *field,
3127 size_t nesting)
3128 {
3129 int ret;
3130
3131 ret = _lttng_struct_type_statedump(session,
3132 lttng_kernel_get_type_struct(field->type), nesting);
3133 if (ret)
3134 return ret;
3135 return lttng_field_name_statedump(session, field, nesting);
3136 }
3137
3138 /*
3139 * Must be called with sessions_mutex held.
3140 */
3141 static
3142 int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
3143 const struct lttng_kernel_type_variant *type,
3144 size_t nesting,
3145 const char *prev_field_name)
3146 {
3147 const char *tag_name;
3148 int ret;
3149 uint32_t i, nr_choices;
3150
3151 tag_name = type->tag_name;
3152 if (!tag_name)
3153 tag_name = prev_field_name;
3154 if (!tag_name)
3155 return -EINVAL;
3156 /*
3157 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3158 */
3159 if (type->alignment != 0)
3160 return -EINVAL;
3161 ret = print_tabs(session, nesting);
3162 if (ret)
3163 return ret;
3164 ret = lttng_metadata_printf(session,
3165 "variant <_%s> {\n",
3166 tag_name);
3167 if (ret)
3168 return ret;
3169 nr_choices = type->nr_choices;
3170 for (i = 0; i < nr_choices; i++) {
3171 const struct lttng_kernel_event_field *iter_field;
3172
3173 iter_field = type->choices[i];
3174 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3175 if (ret)
3176 return ret;
3177 }
3178 ret = print_tabs(session, nesting);
3179 if (ret)
3180 return ret;
3181 ret = lttng_metadata_printf(session,
3182 "}");
3183 return ret;
3184 }
3185
3186 /*
3187 * Must be called with sessions_mutex held.
3188 */
3189 static
3190 int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3191 const struct lttng_kernel_event_field *field,
3192 size_t nesting,
3193 const char *prev_field_name)
3194 {
3195 int ret;
3196
3197 ret = _lttng_variant_type_statedump(session,
3198 lttng_kernel_get_type_variant(field->type), nesting,
3199 prev_field_name);
3200 if (ret)
3201 return ret;
3202 return lttng_field_name_statedump(session, field, nesting);
3203 }
3204
3205 /*
3206 * Must be called with sessions_mutex held.
3207 */
3208 static
3209 int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3210 const struct lttng_kernel_event_field *field,
3211 size_t nesting)
3212 {
3213 int ret;
3214 const struct lttng_kernel_type_array *array_type;
3215 const struct lttng_kernel_type_common *elem_type;
3216
3217 array_type = lttng_kernel_get_type_array(field->type);
3218 WARN_ON_ONCE(!array_type);
3219
3220 if (array_type->alignment) {
3221 ret = print_tabs(session, nesting);
3222 if (ret)
3223 return ret;
3224 ret = lttng_metadata_printf(session,
3225 "struct { } align(%u) _%s_padding;\n",
3226 array_type->alignment * CHAR_BIT,
3227 field->name);
3228 if (ret)
3229 return ret;
3230 }
3231 /*
3232 * Nested compound types: Only array of structures and variants are
3233 * currently supported.
3234 */
3235 elem_type = array_type->elem_type;
3236 switch (elem_type->type) {
3237 case lttng_kernel_type_integer:
3238 case lttng_kernel_type_struct:
3239 case lttng_kernel_type_variant:
3240 ret = _lttng_type_statedump(session, elem_type,
3241 array_type->encoding, nesting);
3242 if (ret)
3243 return ret;
3244 break;
3245
3246 default:
3247 return -EINVAL;
3248 }
3249 ret = lttng_metadata_printf(session,
3250 " _%s[%u];\n",
3251 field->name,
3252 array_type->length);
3253 return ret;
3254 }
3255
3256 /*
3257 * Must be called with sessions_mutex held.
3258 */
3259 static
3260 int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3261 const struct lttng_kernel_event_field *field,
3262 size_t nesting,
3263 const char *prev_field_name)
3264 {
3265 int ret;
3266 const char *length_name;
3267 const struct lttng_kernel_type_sequence *sequence_type;
3268 const struct lttng_kernel_type_common *elem_type;
3269
3270 sequence_type = lttng_kernel_get_type_sequence(field->type);
3271 WARN_ON_ONCE(!sequence_type);
3272
3273 length_name = sequence_type->length_name;
3274 if (!length_name)
3275 length_name = prev_field_name;
3276 if (!length_name)
3277 return -EINVAL;
3278
3279 if (sequence_type->alignment) {
3280 ret = print_tabs(session, nesting);
3281 if (ret)
3282 return ret;
3283 ret = lttng_metadata_printf(session,
3284 "struct { } align(%u) _%s_padding;\n",
3285 sequence_type->alignment * CHAR_BIT,
3286 field->name);
3287 if (ret)
3288 return ret;
3289 }
3290
3291 /*
3292 * Nested compound types: Only array of structures and variants are
3293 * currently supported.
3294 */
3295 elem_type = sequence_type->elem_type;
3296 switch (elem_type->type) {
3297 case lttng_kernel_type_integer:
3298 case lttng_kernel_type_struct:
3299 case lttng_kernel_type_variant:
3300 ret = _lttng_type_statedump(session, elem_type,
3301 sequence_type->encoding, nesting);
3302 if (ret)
3303 return ret;
3304 break;
3305
3306 default:
3307 return -EINVAL;
3308 }
3309 ret = lttng_metadata_printf(session,
3310 " _%s[ _%s ];\n",
3311 field->name,
3312 length_name);
3313 return ret;
3314 }
3315
3316 /*
3317 * Must be called with sessions_mutex held.
3318 */
3319 static
3320 int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3321 const struct lttng_kernel_type_enum *type,
3322 size_t nesting)
3323 {
3324 const struct lttng_kernel_enum_desc *enum_desc;
3325 const struct lttng_kernel_type_common *container_type;
3326 int ret;
3327 unsigned int i, nr_entries;
3328
3329 container_type = type->container_type;
3330 if (container_type->type != lttng_kernel_type_integer) {
3331 ret = -EINVAL;
3332 goto end;
3333 }
3334 enum_desc = type->desc;
3335 nr_entries = enum_desc->nr_entries;
3336
3337 ret = print_tabs(session, nesting);
3338 if (ret)
3339 goto end;
3340 ret = lttng_metadata_printf(session, "enum : ");
3341 if (ret)
3342 goto end;
3343 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3344 lttng_kernel_string_encoding_none, 0);
3345 if (ret)
3346 goto end;
3347 ret = lttng_metadata_printf(session, " {\n");
3348 if (ret)
3349 goto end;
3350 /* Dump all entries */
3351 for (i = 0; i < nr_entries; i++) {
3352 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3353 int j, len;
3354
3355 ret = print_tabs(session, nesting + 1);
3356 if (ret)
3357 goto end;
3358 ret = lttng_metadata_printf(session,
3359 "\"");
3360 if (ret)
3361 goto end;
3362 len = strlen(entry->string);
3363 /* Escape the character '"' */
3364 for (j = 0; j < len; j++) {
3365 char c = entry->string[j];
3366
3367 switch (c) {
3368 case '"':
3369 ret = lttng_metadata_printf(session,
3370 "\\\"");
3371 break;
3372 case '\\':
3373 ret = lttng_metadata_printf(session,
3374 "\\\\");
3375 break;
3376 default:
3377 ret = lttng_metadata_printf(session,
3378 "%c", c);
3379 break;
3380 }
3381 if (ret)
3382 goto end;
3383 }
3384 ret = lttng_metadata_printf(session, "\"");
3385 if (ret)
3386 goto end;
3387
3388 if (entry->options.is_auto) {
3389 ret = lttng_metadata_printf(session, ",\n");
3390 if (ret)
3391 goto end;
3392 } else {
3393 ret = lttng_metadata_printf(session,
3394 " = ");
3395 if (ret)
3396 goto end;
3397 if (entry->start.signedness)
3398 ret = lttng_metadata_printf(session,
3399 "%lld", (long long) entry->start.value);
3400 else
3401 ret = lttng_metadata_printf(session,
3402 "%llu", entry->start.value);
3403 if (ret)
3404 goto end;
3405 if (entry->start.signedness == entry->end.signedness &&
3406 entry->start.value
3407 == entry->end.value) {
3408 ret = lttng_metadata_printf(session,
3409 ",\n");
3410 } else {
3411 if (entry->end.signedness) {
3412 ret = lttng_metadata_printf(session,
3413 " ... %lld,\n",
3414 (long long) entry->end.value);
3415 } else {
3416 ret = lttng_metadata_printf(session,
3417 " ... %llu,\n",
3418 entry->end.value);
3419 }
3420 }
3421 if (ret)
3422 goto end;
3423 }
3424 }
3425 ret = print_tabs(session, nesting);
3426 if (ret)
3427 goto end;
3428 ret = lttng_metadata_printf(session, "}");
3429 end:
3430 return ret;
3431 }
3432
3433 /*
3434 * Must be called with sessions_mutex held.
3435 */
3436 static
3437 int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3438 const struct lttng_kernel_event_field *field,
3439 size_t nesting)
3440 {
3441 int ret;
3442 const struct lttng_kernel_type_enum *enum_type;
3443
3444 enum_type = lttng_kernel_get_type_enum(field->type);
3445 WARN_ON_ONCE(!enum_type);
3446 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3447 if (ret)
3448 return ret;
3449 return lttng_field_name_statedump(session, field, nesting);
3450 }
3451
3452 static
3453 int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3454 const struct lttng_kernel_event_field *field,
3455 size_t nesting)
3456 {
3457 int ret;
3458
3459 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3460 lttng_kernel_string_encoding_none, nesting);
3461 if (ret)
3462 return ret;
3463 return lttng_field_name_statedump(session, field, nesting);
3464 }
3465
3466 static
3467 int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3468 const struct lttng_kernel_type_string *type,
3469 size_t nesting)
3470 {
3471 int ret;
3472
3473 /* Default encoding is UTF8 */
3474 ret = print_tabs(session, nesting);
3475 if (ret)
3476 return ret;
3477 ret = lttng_metadata_printf(session,
3478 "string%s",
3479 type->encoding == lttng_kernel_string_encoding_ASCII ?
3480 " { encoding = ASCII; }" : "");
3481 return ret;
3482 }
3483
3484 static
3485 int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3486 const struct lttng_kernel_event_field *field,
3487 size_t nesting)
3488 {
3489 const struct lttng_kernel_type_string *string_type;
3490 int ret;
3491
3492 string_type = lttng_kernel_get_type_string(field->type);
3493 WARN_ON_ONCE(!string_type);
3494 ret = _lttng_string_type_statedump(session, string_type, nesting);
3495 if (ret)
3496 return ret;
3497 return lttng_field_name_statedump(session, field, nesting);
3498 }
3499
3500 /*
3501 * Must be called with sessions_mutex held.
3502 */
3503 static
3504 int _lttng_type_statedump(struct lttng_kernel_session *session,
3505 const struct lttng_kernel_type_common *type,
3506 enum lttng_kernel_string_encoding parent_encoding,
3507 size_t nesting)
3508 {
3509 int ret = 0;
3510
3511 switch (type->type) {
3512 case lttng_kernel_type_integer:
3513 ret = _lttng_integer_type_statedump(session,
3514 lttng_kernel_get_type_integer(type),
3515 parent_encoding, nesting);
3516 break;
3517 case lttng_kernel_type_enum:
3518 ret = _lttng_enum_type_statedump(session,
3519 lttng_kernel_get_type_enum(type),
3520 nesting);
3521 break;
3522 case lttng_kernel_type_string:
3523 ret = _lttng_string_type_statedump(session,
3524 lttng_kernel_get_type_string(type),
3525 nesting);
3526 break;
3527 case lttng_kernel_type_struct:
3528 ret = _lttng_struct_type_statedump(session,
3529 lttng_kernel_get_type_struct(type),
3530 nesting);
3531 break;
3532 case lttng_kernel_type_variant:
3533 ret = _lttng_variant_type_statedump(session,
3534 lttng_kernel_get_type_variant(type),
3535 nesting, NULL);
3536 break;
3537
3538 /* Nested arrays and sequences are not supported yet. */
3539 case lttng_kernel_type_array:
3540 case lttng_kernel_type_sequence:
3541 default:
3542 WARN_ON_ONCE(1);
3543 return -EINVAL;
3544 }
3545 return ret;
3546 }
3547
3548 /*
3549 * Must be called with sessions_mutex held.
3550 */
3551 static
3552 int _lttng_field_statedump(struct lttng_kernel_session *session,
3553 const struct lttng_kernel_event_field *field,
3554 size_t nesting,
3555 const char **prev_field_name_p)
3556 {
3557 const char *prev_field_name = NULL;
3558 int ret = 0;
3559
3560 if (prev_field_name_p)
3561 prev_field_name = *prev_field_name_p;
3562 switch (field->type->type) {
3563 case lttng_kernel_type_integer:
3564 ret = _lttng_integer_field_statedump(session, field, nesting);
3565 break;
3566 case lttng_kernel_type_enum:
3567 ret = _lttng_enum_field_statedump(session, field, nesting);
3568 break;
3569 case lttng_kernel_type_string:
3570 ret = _lttng_string_field_statedump(session, field, nesting);
3571 break;
3572 case lttng_kernel_type_struct:
3573 ret = _lttng_struct_field_statedump(session, field, nesting);
3574 break;
3575 case lttng_kernel_type_array:
3576 ret = _lttng_array_field_statedump(session, field, nesting);
3577 break;
3578 case lttng_kernel_type_sequence:
3579 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3580 break;
3581 case lttng_kernel_type_variant:
3582 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3583 break;
3584
3585 default:
3586 WARN_ON_ONCE(1);
3587 return -EINVAL;
3588 }
3589 if (prev_field_name_p)
3590 *prev_field_name_p = field->name;
3591 return ret;
3592 }
3593
3594 static
3595 int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3596 struct lttng_kernel_ctx *ctx)
3597 {
3598 const char *prev_field_name = NULL;
3599 int ret = 0;
3600 int i;
3601
3602 if (!ctx)
3603 return 0;
3604 for (i = 0; i < ctx->nr_fields; i++) {
3605 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3606
3607 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3608 if (ret)
3609 return ret;
3610 }
3611 return ret;
3612 }
3613
3614 static
3615 int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3616 struct lttng_kernel_event_recorder *event_recorder)
3617 {
3618 const char *prev_field_name = NULL;
3619 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3620 int ret = 0;
3621 int i;
3622
3623 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3624 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3625
3626 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3627 if (ret)
3628 return ret;
3629 }
3630 return ret;
3631 }
3632
3633 /*
3634 * Must be called with sessions_mutex held.
3635 * The entire event metadata is printed as a single atomic metadata
3636 * transaction.
3637 */
3638 static
3639 int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
3640 struct lttng_kernel_channel_buffer *chan,
3641 struct lttng_kernel_event_recorder *event_recorder)
3642 {
3643 int ret = 0;
3644
3645 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3646 return 0;
3647 if (chan->priv->channel_type == METADATA_CHANNEL)
3648 return 0;
3649
3650 lttng_metadata_begin(session);
3651
3652 ret = lttng_metadata_printf(session,
3653 "event {\n"
3654 " name = \"%s\";\n"
3655 " id = %u;\n"
3656 " stream_id = %u;\n",
3657 event_recorder->priv->parent.desc->event_name,
3658 event_recorder->priv->id,
3659 event_recorder->chan->priv->id);
3660 if (ret)
3661 goto end;
3662
3663 ret = lttng_metadata_printf(session,
3664 " fields := struct {\n"
3665 );
3666 if (ret)
3667 goto end;
3668
3669 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3670 if (ret)
3671 goto end;
3672
3673 /*
3674 * LTTng space reservation can only reserve multiples of the
3675 * byte size.
3676 */
3677 ret = lttng_metadata_printf(session,
3678 " };\n"
3679 "};\n\n");
3680 if (ret)
3681 goto end;
3682
3683 event_recorder->priv->metadata_dumped = 1;
3684 end:
3685 lttng_metadata_end(session);
3686 return ret;
3687
3688 }
3689
3690 /*
3691 * Must be called with sessions_mutex held.
3692 * The entire channel metadata is printed as a single atomic metadata
3693 * transaction.
3694 */
3695 static
3696 int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3697 struct lttng_kernel_channel_buffer *chan)
3698 {
3699 int ret = 0;
3700
3701 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3702 return 0;
3703
3704 if (chan->priv->channel_type == METADATA_CHANNEL)
3705 return 0;
3706
3707 lttng_metadata_begin(session);
3708
3709 WARN_ON_ONCE(!chan->priv->header_type);
3710 ret = lttng_metadata_printf(session,
3711 "stream {\n"
3712 " id = %u;\n"
3713 " event.header := %s;\n"
3714 " packet.context := struct packet_context;\n",
3715 chan->priv->id,
3716 chan->priv->header_type == 1 ? "struct event_header_compact" :
3717 "struct event_header_large");
3718 if (ret)
3719 goto end;
3720
3721 if (chan->priv->ctx) {
3722 ret = lttng_metadata_printf(session,
3723 " event.context := struct {\n");
3724 if (ret)
3725 goto end;
3726 }
3727 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3728 if (ret)
3729 goto end;
3730 if (chan->priv->ctx) {
3731 ret = lttng_metadata_printf(session,
3732 " };\n");
3733 if (ret)
3734 goto end;
3735 }
3736
3737 ret = lttng_metadata_printf(session,
3738 "};\n\n");
3739
3740 chan->priv->metadata_dumped = 1;
3741 end:
3742 lttng_metadata_end(session);
3743 return ret;
3744 }
3745
3746 /*
3747 * Must be called with sessions_mutex held.
3748 */
3749 static
3750 int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3751 {
3752 return lttng_metadata_printf(session,
3753 "struct packet_context {\n"
3754 " uint64_clock_monotonic_t timestamp_begin;\n"
3755 " uint64_clock_monotonic_t timestamp_end;\n"
3756 " uint64_t content_size;\n"
3757 " uint64_t packet_size;\n"
3758 " uint64_t packet_seq_num;\n"
3759 " unsigned long events_discarded;\n"
3760 " uint32_t cpu_id;\n"
3761 "};\n\n"
3762 );
3763 }
3764
3765 /*
3766 * Compact header:
3767 * id: range: 0 - 30.
3768 * id 31 is reserved to indicate an extended header.
3769 *
3770 * Large header:
3771 * id: range: 0 - 65534.
3772 * id 65535 is reserved to indicate an extended header.
3773 *
3774 * Must be called with sessions_mutex held.
3775 */
3776 static
3777 int _lttng_event_header_declare(struct lttng_kernel_session *session)
3778 {
3779 return lttng_metadata_printf(session,
3780 "struct event_header_compact {\n"
3781 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3782 " variant <id> {\n"
3783 " struct {\n"
3784 " uint27_clock_monotonic_t timestamp;\n"
3785 " } compact;\n"
3786 " struct {\n"
3787 " uint32_t id;\n"
3788 " uint64_clock_monotonic_t timestamp;\n"
3789 " } extended;\n"
3790 " } v;\n"
3791 "} align(%u);\n"
3792 "\n"
3793 "struct event_header_large {\n"
3794 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3795 " variant <id> {\n"
3796 " struct {\n"
3797 " uint32_clock_monotonic_t timestamp;\n"
3798 " } compact;\n"
3799 " struct {\n"
3800 " uint32_t id;\n"
3801 " uint64_clock_monotonic_t timestamp;\n"
3802 " } extended;\n"
3803 " } v;\n"
3804 "} align(%u);\n\n",
3805 lttng_alignof(uint32_t) * CHAR_BIT,
3806 lttng_alignof(uint16_t) * CHAR_BIT
3807 );
3808 }
3809
3810 /*
3811 * Approximation of NTP time of day to clock monotonic correlation,
3812 * taken at start of trace.
3813 * Yes, this is only an approximation. Yes, we can (and will) do better
3814 * in future versions.
3815 * This function may return a negative offset. It may happen if the
3816 * system sets the REALTIME clock to 0 after boot.
3817 *
3818 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3819 * y2038 compliant.
3820 */
3821 static
3822 int64_t measure_clock_offset(void)
3823 {
3824 uint64_t monotonic_avg, monotonic[2], realtime;
3825 uint64_t tcf = trace_clock_freq();
3826 int64_t offset;
3827 unsigned long flags;
3828 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3829 struct timespec64 rts = { 0, 0 };
3830 #else
3831 struct timespec rts = { 0, 0 };
3832 #endif
3833
3834 /* Disable interrupts to increase correlation precision. */
3835 local_irq_save(flags);
3836 monotonic[0] = trace_clock_read64();
3837 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3838 ktime_get_real_ts64(&rts);
3839 #else
3840 getnstimeofday(&rts);
3841 #endif
3842 monotonic[1] = trace_clock_read64();
3843 local_irq_restore(flags);
3844
3845 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3846 realtime = (uint64_t) rts.tv_sec * tcf;
3847 if (tcf == NSEC_PER_SEC) {
3848 realtime += rts.tv_nsec;
3849 } else {
3850 uint64_t n = rts.tv_nsec * tcf;
3851
3852 do_div(n, NSEC_PER_SEC);
3853 realtime += n;
3854 }
3855 offset = (int64_t) realtime - monotonic_avg;
3856 return offset;
3857 }
3858
3859 static
3860 int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3861 {
3862 int ret = 0;
3863 size_t i;
3864 char cur;
3865
3866 i = 0;
3867 cur = string[i];
3868 while (cur != '\0') {
3869 switch (cur) {
3870 case '\n':
3871 ret = lttng_metadata_printf(session, "%s", "\\n");
3872 break;
3873 case '\\':
3874 case '"':
3875 ret = lttng_metadata_printf(session, "%c", '\\');
3876 if (ret)
3877 goto error;
3878 /* We still print the current char */
3879 /* Fallthrough */
3880 default:
3881 ret = lttng_metadata_printf(session, "%c", cur);
3882 break;
3883 }
3884
3885 if (ret)
3886 goto error;
3887
3888 cur = string[++i];
3889 }
3890 error:
3891 return ret;
3892 }
3893
3894 static
3895 int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3896 const char *field_value)
3897 {
3898 int ret;
3899
3900 ret = lttng_metadata_printf(session, " %s = \"", field);
3901 if (ret)
3902 goto error;
3903
3904 ret = print_escaped_ctf_string(session, field_value);
3905 if (ret)
3906 goto error;
3907
3908 ret = lttng_metadata_printf(session, "\";\n");
3909
3910 error:
3911 return ret;
3912 }
3913
3914 /*
3915 * Output metadata into this session's metadata buffers.
3916 * Must be called with sessions_mutex held.
3917 */
3918 static
3919 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3920 {
3921 unsigned char *uuid_c = session->priv->uuid.b;
3922 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3923 const char *product_uuid;
3924 struct lttng_kernel_channel_buffer_private *chan_priv;
3925 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3926 int ret = 0;
3927
3928 if (!LTTNG_READ_ONCE(session->active))
3929 return 0;
3930
3931 lttng_metadata_begin(session);
3932
3933 if (session->priv->metadata_dumped)
3934 goto skip_session;
3935
3936 snprintf(uuid_s, sizeof(uuid_s),
3937 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3938 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3939 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3940 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3941 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3942
3943 ret = lttng_metadata_printf(session,
3944 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3945 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3946 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3947 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3948 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3949 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3950 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3951 "\n"
3952 "trace {\n"
3953 " major = %u;\n"
3954 " minor = %u;\n"
3955 " uuid = \"%s\";\n"
3956 " byte_order = %s;\n"
3957 " packet.header := struct {\n"
3958 " uint32_t magic;\n"
3959 " uint8_t uuid[16];\n"
3960 " uint32_t stream_id;\n"
3961 " uint64_t stream_instance_id;\n"
3962 " };\n"
3963 "};\n\n",
3964 lttng_alignof(uint8_t) * CHAR_BIT,
3965 lttng_alignof(uint16_t) * CHAR_BIT,
3966 lttng_alignof(uint32_t) * CHAR_BIT,
3967 lttng_alignof(uint64_t) * CHAR_BIT,
3968 sizeof(unsigned long) * CHAR_BIT,
3969 lttng_alignof(unsigned long) * CHAR_BIT,
3970 CTF_SPEC_MAJOR,
3971 CTF_SPEC_MINOR,
3972 uuid_s,
3973 #if __BYTE_ORDER == __BIG_ENDIAN
3974 "be"
3975 #else
3976 "le"
3977 #endif
3978 );
3979 if (ret)
3980 goto end;
3981
3982 ret = lttng_metadata_printf(session,
3983 "env {\n"
3984 " hostname = \"%s\";\n"
3985 " domain = \"kernel\";\n"
3986 " sysname = \"%s\";\n"
3987 " kernel_release = \"%s\";\n"
3988 " kernel_version = \"%s\";\n"
3989 " tracer_name = \"lttng-modules\";\n"
3990 " tracer_major = %d;\n"
3991 " tracer_minor = %d;\n"
3992 " tracer_patchlevel = %d;\n"
3993 " trace_buffering_scheme = \"global\";\n",
3994 current->nsproxy->uts_ns->name.nodename,
3995 utsname()->sysname,
3996 utsname()->release,
3997 utsname()->version,
3998 LTTNG_MODULES_MAJOR_VERSION,
3999 LTTNG_MODULES_MINOR_VERSION,
4000 LTTNG_MODULES_PATCHLEVEL_VERSION
4001 );
4002 if (ret)
4003 goto end;
4004
4005 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
4006 if (ret)
4007 goto end;
4008 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
4009 session->priv->creation_time);
4010 if (ret)
4011 goto end;
4012
4013 /* Add the product UUID to the 'env' section */
4014 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
4015 if (product_uuid) {
4016 ret = lttng_metadata_printf(session,
4017 " product_uuid = \"%s\";\n",
4018 product_uuid
4019 );
4020 if (ret)
4021 goto end;
4022 }
4023
4024 /* Close the 'env' section */
4025 ret = lttng_metadata_printf(session, "};\n\n");
4026 if (ret)
4027 goto end;
4028
4029 ret = lttng_metadata_printf(session,
4030 "clock {\n"
4031 " name = \"%s\";\n",
4032 trace_clock_name()
4033 );
4034 if (ret)
4035 goto end;
4036
4037 if (!trace_clock_uuid(clock_uuid_s)) {
4038 ret = lttng_metadata_printf(session,
4039 " uuid = \"%s\";\n",
4040 clock_uuid_s
4041 );
4042 if (ret)
4043 goto end;
4044 }
4045
4046 ret = lttng_metadata_printf(session,
4047 " description = \"%s\";\n"
4048 " freq = %llu; /* Frequency, in Hz */\n"
4049 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
4050 " offset = %lld;\n"
4051 "};\n\n",
4052 trace_clock_description(),
4053 (unsigned long long) trace_clock_freq(),
4054 (long long) measure_clock_offset()
4055 );
4056 if (ret)
4057 goto end;
4058
4059 ret = lttng_metadata_printf(session,
4060 "typealias integer {\n"
4061 " size = 27; align = 1; signed = false;\n"
4062 " map = clock.%s.value;\n"
4063 "} := uint27_clock_monotonic_t;\n"
4064 "\n"
4065 "typealias integer {\n"
4066 " size = 32; align = %u; signed = false;\n"
4067 " map = clock.%s.value;\n"
4068 "} := uint32_clock_monotonic_t;\n"
4069 "\n"
4070 "typealias integer {\n"
4071 " size = 64; align = %u; signed = false;\n"
4072 " map = clock.%s.value;\n"
4073 "} := uint64_clock_monotonic_t;\n\n",
4074 trace_clock_name(),
4075 lttng_alignof(uint32_t) * CHAR_BIT,
4076 trace_clock_name(),
4077 lttng_alignof(uint64_t) * CHAR_BIT,
4078 trace_clock_name()
4079 );
4080 if (ret)
4081 goto end;
4082
4083 ret = _lttng_stream_packet_context_declare(session);
4084 if (ret)
4085 goto end;
4086
4087 ret = _lttng_event_header_declare(session);
4088 if (ret)
4089 goto end;
4090
4091 skip_session:
4092 list_for_each_entry(chan_priv, &session->priv->chan, node) {
4093 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
4094 if (ret)
4095 goto end;
4096 }
4097
4098 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
4099 ret = _lttng_event_metadata_statedump(session, event_recorder_priv->pub->chan,
4100 event_recorder_priv->pub);
4101 if (ret)
4102 goto end;
4103 }
4104 session->priv->metadata_dumped = 1;
4105 end:
4106 lttng_metadata_end(session);
4107 return ret;
4108 }
4109
4110 /**
4111 * lttng_transport_register - LTT transport registration
4112 * @transport: transport structure
4113 *
4114 * Registers a transport which can be used as output to extract the data out of
4115 * LTTng. The module calling this registration function must ensure that no
4116 * trap-inducing code will be executed by the transport functions. E.g.
4117 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
4118 * is made visible to the transport function. This registration acts as a
4119 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
4120 * after its registration must it synchronize the TLBs.
4121 */
4122 void lttng_transport_register(struct lttng_transport *transport)
4123 {
4124 /*
4125 * Make sure no page fault can be triggered by the module about to be
4126 * registered. We deal with this here so we don't have to call
4127 * vmalloc_sync_mappings() in each module's init.
4128 */
4129 wrapper_vmalloc_sync_mappings();
4130
4131 mutex_lock(&sessions_mutex);
4132 list_add_tail(&transport->node, &lttng_transport_list);
4133 mutex_unlock(&sessions_mutex);
4134 }
4135 EXPORT_SYMBOL_GPL(lttng_transport_register);
4136
4137 /**
4138 * lttng_transport_unregister - LTT transport unregistration
4139 * @transport: transport structure
4140 */
4141 void lttng_transport_unregister(struct lttng_transport *transport)
4142 {
4143 mutex_lock(&sessions_mutex);
4144 list_del(&transport->node);
4145 mutex_unlock(&sessions_mutex);
4146 }
4147 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4148
4149 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4150 {
4151 /*
4152 * Make sure no page fault can be triggered by the module about to be
4153 * registered. We deal with this here so we don't have to call
4154 * vmalloc_sync_mappings() in each module's init.
4155 */
4156 wrapper_vmalloc_sync_mappings();
4157
4158 mutex_lock(&sessions_mutex);
4159 list_add_tail(&transport->node, &lttng_counter_transport_list);
4160 mutex_unlock(&sessions_mutex);
4161 }
4162 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4163
4164 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4165 {
4166 mutex_lock(&sessions_mutex);
4167 list_del(&transport->node);
4168 mutex_unlock(&sessions_mutex);
4169 }
4170 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4171
4172 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4173
4174 enum cpuhp_state lttng_hp_prepare;
4175 enum cpuhp_state lttng_hp_online;
4176
4177 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4178 {
4179 struct lttng_cpuhp_node *lttng_node;
4180
4181 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4182 switch (lttng_node->component) {
4183 case LTTNG_RING_BUFFER_FRONTEND:
4184 return 0;
4185 case LTTNG_RING_BUFFER_BACKEND:
4186 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4187 case LTTNG_RING_BUFFER_ITER:
4188 return 0;
4189 case LTTNG_CONTEXT_PERF_COUNTERS:
4190 return 0;
4191 default:
4192 return -EINVAL;
4193 }
4194 }
4195
4196 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4197 {
4198 struct lttng_cpuhp_node *lttng_node;
4199
4200 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4201 switch (lttng_node->component) {
4202 case LTTNG_RING_BUFFER_FRONTEND:
4203 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4204 case LTTNG_RING_BUFFER_BACKEND:
4205 return 0;
4206 case LTTNG_RING_BUFFER_ITER:
4207 return 0;
4208 case LTTNG_CONTEXT_PERF_COUNTERS:
4209 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4210 default:
4211 return -EINVAL;
4212 }
4213 }
4214
4215 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4216 {
4217 struct lttng_cpuhp_node *lttng_node;
4218
4219 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4220 switch (lttng_node->component) {
4221 case LTTNG_RING_BUFFER_FRONTEND:
4222 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4223 case LTTNG_RING_BUFFER_BACKEND:
4224 return 0;
4225 case LTTNG_RING_BUFFER_ITER:
4226 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4227 case LTTNG_CONTEXT_PERF_COUNTERS:
4228 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4229 default:
4230 return -EINVAL;
4231 }
4232 }
4233
4234 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4235 {
4236 struct lttng_cpuhp_node *lttng_node;
4237
4238 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4239 switch (lttng_node->component) {
4240 case LTTNG_RING_BUFFER_FRONTEND:
4241 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4242 case LTTNG_RING_BUFFER_BACKEND:
4243 return 0;
4244 case LTTNG_RING_BUFFER_ITER:
4245 return 0;
4246 case LTTNG_CONTEXT_PERF_COUNTERS:
4247 return 0;
4248 default:
4249 return -EINVAL;
4250 }
4251 }
4252
4253 static int __init lttng_init_cpu_hotplug(void)
4254 {
4255 int ret;
4256
4257 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4258 lttng_hotplug_prepare,
4259 lttng_hotplug_dead);
4260 if (ret < 0) {
4261 return ret;
4262 }
4263 lttng_hp_prepare = ret;
4264 lttng_rb_set_hp_prepare(ret);
4265
4266 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4267 lttng_hotplug_online,
4268 lttng_hotplug_offline);
4269 if (ret < 0) {
4270 cpuhp_remove_multi_state(lttng_hp_prepare);
4271 lttng_hp_prepare = 0;
4272 return ret;
4273 }
4274 lttng_hp_online = ret;
4275 lttng_rb_set_hp_online(ret);
4276
4277 return 0;
4278 }
4279
4280 static void __exit lttng_exit_cpu_hotplug(void)
4281 {
4282 lttng_rb_set_hp_online(0);
4283 cpuhp_remove_multi_state(lttng_hp_online);
4284 lttng_rb_set_hp_prepare(0);
4285 cpuhp_remove_multi_state(lttng_hp_prepare);
4286 }
4287
4288 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4289 static int lttng_init_cpu_hotplug(void)
4290 {
4291 return 0;
4292 }
4293 static void lttng_exit_cpu_hotplug(void)
4294 {
4295 }
4296 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4297
4298 static int __init lttng_events_init(void)
4299 {
4300 int ret;
4301
4302 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4303 if (ret)
4304 return ret;
4305 ret = wrapper_get_pfnblock_flags_mask_init();
4306 if (ret)
4307 return ret;
4308 ret = wrapper_get_pageblock_flags_mask_init();
4309 if (ret)
4310 return ret;
4311 ret = lttng_probes_init();
4312 if (ret)
4313 return ret;
4314 ret = lttng_context_init();
4315 if (ret)
4316 return ret;
4317 ret = lttng_tracepoint_init();
4318 if (ret)
4319 goto error_tp;
4320 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4321 if (!event_recorder_cache) {
4322 ret = -ENOMEM;
4323 goto error_kmem_event_recorder;
4324 }
4325 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4326 if (!event_recorder_private_cache) {
4327 ret = -ENOMEM;
4328 goto error_kmem_event_recorder_private;
4329 }
4330 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4331 if (!event_notifier_cache) {
4332 ret = -ENOMEM;
4333 goto error_kmem_event_notifier;
4334 }
4335 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4336 if (!event_notifier_private_cache) {
4337 ret = -ENOMEM;
4338 goto error_kmem_event_notifier_private;
4339 }
4340 ret = lttng_abi_init();
4341 if (ret)
4342 goto error_abi;
4343 ret = lttng_logger_init();
4344 if (ret)
4345 goto error_logger;
4346 ret = lttng_init_cpu_hotplug();
4347 if (ret)
4348 goto error_hotplug;
4349 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4350 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4351 __stringify(LTTNG_MODULES_MINOR_VERSION),
4352 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4353 LTTNG_MODULES_EXTRAVERSION,
4354 LTTNG_VERSION_NAME,
4355 #ifdef LTTNG_EXTRA_VERSION_GIT
4356 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4357 #else
4358 "",
4359 #endif
4360 #ifdef LTTNG_EXTRA_VERSION_NAME
4361 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4362 #else
4363 "");
4364 #endif
4365 return 0;
4366
4367 error_hotplug:
4368 lttng_logger_exit();
4369 error_logger:
4370 lttng_abi_exit();
4371 error_abi:
4372 kmem_cache_destroy(event_notifier_private_cache);
4373 error_kmem_event_notifier_private:
4374 kmem_cache_destroy(event_notifier_cache);
4375 error_kmem_event_notifier:
4376 kmem_cache_destroy(event_recorder_private_cache);
4377 error_kmem_event_recorder_private:
4378 kmem_cache_destroy(event_recorder_cache);
4379 error_kmem_event_recorder:
4380 lttng_tracepoint_exit();
4381 error_tp:
4382 lttng_context_exit();
4383 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4384 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4385 __stringify(LTTNG_MODULES_MINOR_VERSION),
4386 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4387 LTTNG_MODULES_EXTRAVERSION,
4388 LTTNG_VERSION_NAME,
4389 #ifdef LTTNG_EXTRA_VERSION_GIT
4390 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4391 #else
4392 "",
4393 #endif
4394 #ifdef LTTNG_EXTRA_VERSION_NAME
4395 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4396 #else
4397 "");
4398 #endif
4399 return ret;
4400 }
4401
4402 module_init(lttng_events_init);
4403
4404 static void __exit lttng_events_exit(void)
4405 {
4406 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4407
4408 lttng_exit_cpu_hotplug();
4409 lttng_logger_exit();
4410 lttng_abi_exit();
4411 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4412 lttng_session_destroy(session_priv->pub);
4413 kmem_cache_destroy(event_recorder_cache);
4414 kmem_cache_destroy(event_recorder_private_cache);
4415 kmem_cache_destroy(event_notifier_cache);
4416 kmem_cache_destroy(event_notifier_private_cache);
4417 lttng_tracepoint_exit();
4418 lttng_context_exit();
4419 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4420 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4421 __stringify(LTTNG_MODULES_MINOR_VERSION),
4422 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4423 LTTNG_MODULES_EXTRAVERSION,
4424 LTTNG_VERSION_NAME,
4425 #ifdef LTTNG_EXTRA_VERSION_GIT
4426 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4427 #else
4428 "",
4429 #endif
4430 #ifdef LTTNG_EXTRA_VERSION_NAME
4431 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4432 #else
4433 "");
4434 #endif
4435 }
4436
4437 module_exit(lttng_events_exit);
4438
4439 #include <generated/patches.h>
4440 #ifdef LTTNG_EXTRA_VERSION_GIT
4441 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4442 #endif
4443 #ifdef LTTNG_EXTRA_VERSION_NAME
4444 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4445 #endif
4446 MODULE_LICENSE("GPL and additional rights");
4447 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4448 MODULE_DESCRIPTION("LTTng tracer");
4449 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4450 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4451 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4452 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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