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