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