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SoW-2019-0002: Dynamic Snapshot
[deliverable/lttng-modules.git] / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
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/uuid.h>
30 #include <linux/dmi.h>
31
32 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_all() */
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-tracer.h>
40 #include <lttng-abi-old.h>
41 #include <lttng-endian.h>
42 #include <lttng-string-utils.h>
43 #include <lttng-utils.h>
44 #include <wrapper/ringbuffer/backend.h>
45 #include <wrapper/ringbuffer/frontend.h>
46
47 #define METADATA_CACHE_DEFAULT_SIZE 4096
48
49 static LIST_HEAD(sessions);
50 static LIST_HEAD(trigger_groups);
51 static LIST_HEAD(lttng_transport_list);
52 /*
53 * Protect the sessions and metadata caches.
54 */
55 static DEFINE_MUTEX(sessions_mutex);
56 static struct kmem_cache *event_cache;
57 static struct kmem_cache *trigger_cache;
58
59 static void lttng_session_lazy_sync_event_enablers(struct lttng_session *session);
60 static void lttng_session_sync_event_enablers(struct lttng_session *session);
61 static void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler);
62 static void lttng_trigger_enabler_destroy(struct lttng_trigger_enabler *trigger_enabler);
63 static void lttng_trigger_group_sync_enablers(struct lttng_trigger_group *trigger_group);
64
65 static void _lttng_event_destroy(struct lttng_event *event);
66 static void _lttng_trigger_destroy(struct lttng_trigger *trigger);
67 static void _lttng_channel_destroy(struct lttng_channel *chan);
68 static int _lttng_event_unregister(struct lttng_event *event);
69 static int _lttng_trigger_unregister(struct lttng_trigger *trigger);
70 static
71 int _lttng_event_metadata_statedump(struct lttng_session *session,
72 struct lttng_channel *chan,
73 struct lttng_event *event);
74 static
75 int _lttng_session_metadata_statedump(struct lttng_session *session);
76 static
77 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
78 static
79 int _lttng_field_statedump(struct lttng_session *session,
80 const struct lttng_event_field *field,
81 size_t nesting);
82
83 void synchronize_trace(void)
84 {
85 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,1,0))
86 synchronize_rcu();
87 #else
88 synchronize_sched();
89 #endif
90
91 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
92 #ifdef CONFIG_PREEMPT_RT_FULL
93 synchronize_rcu();
94 #endif
95 #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
96 #ifdef CONFIG_PREEMPT_RT
97 synchronize_rcu();
98 #endif
99 #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
100 }
101
102 void lttng_lock_sessions(void)
103 {
104 mutex_lock(&sessions_mutex);
105 }
106
107 void lttng_unlock_sessions(void)
108 {
109 mutex_unlock(&sessions_mutex);
110 }
111
112 static struct lttng_transport *lttng_transport_find(const char *name)
113 {
114 struct lttng_transport *transport;
115
116 list_for_each_entry(transport, &lttng_transport_list, node) {
117 if (!strcmp(transport->name, name))
118 return transport;
119 }
120 return NULL;
121 }
122
123 /*
124 * Called with sessions lock held.
125 */
126 int lttng_session_active(void)
127 {
128 struct lttng_session *iter;
129
130 list_for_each_entry(iter, &sessions, list) {
131 if (iter->active)
132 return 1;
133 }
134 return 0;
135 }
136
137 struct lttng_session *lttng_session_create(void)
138 {
139 struct lttng_session *session;
140 struct lttng_metadata_cache *metadata_cache;
141 int i;
142
143 mutex_lock(&sessions_mutex);
144 session = lttng_kvzalloc(sizeof(struct lttng_session), GFP_KERNEL);
145 if (!session)
146 goto err;
147 INIT_LIST_HEAD(&session->chan);
148 INIT_LIST_HEAD(&session->events);
149 uuid_le_gen(&session->uuid);
150
151 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
152 GFP_KERNEL);
153 if (!metadata_cache)
154 goto err_free_session;
155 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
156 if (!metadata_cache->data)
157 goto err_free_cache;
158 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
159 kref_init(&metadata_cache->refcount);
160 mutex_init(&metadata_cache->lock);
161 session->metadata_cache = metadata_cache;
162 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
163 memcpy(&metadata_cache->uuid, &session->uuid,
164 sizeof(metadata_cache->uuid));
165 INIT_LIST_HEAD(&session->enablers_head);
166 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
167 INIT_HLIST_HEAD(&session->events_ht.table[i]);
168 list_add(&session->list, &sessions);
169 session->pid_tracker.session = session;
170 session->pid_tracker.tracker_type = TRACKER_PID;
171 session->vpid_tracker.session = session;
172 session->vpid_tracker.tracker_type = TRACKER_VPID;
173 session->uid_tracker.session = session;
174 session->uid_tracker.tracker_type = TRACKER_UID;
175 session->vuid_tracker.session = session;
176 session->vuid_tracker.tracker_type = TRACKER_VUID;
177 session->gid_tracker.session = session;
178 session->gid_tracker.tracker_type = TRACKER_GID;
179 session->vgid_tracker.session = session;
180 session->vgid_tracker.tracker_type = TRACKER_VGID;
181 mutex_unlock(&sessions_mutex);
182 return session;
183
184 err_free_cache:
185 kfree(metadata_cache);
186 err_free_session:
187 lttng_kvfree(session);
188 err:
189 mutex_unlock(&sessions_mutex);
190 return NULL;
191 }
192
193 struct lttng_trigger_group *lttng_trigger_group_create(void)
194 {
195 struct lttng_transport *transport = NULL;
196 struct lttng_trigger_group *trigger_group;
197 const char *transport_name = "relay-trigger";
198 size_t subbuf_size = 4096; //TODO
199 size_t num_subbuf = 16; //TODO
200 unsigned int switch_timer_interval = 0;
201 unsigned int read_timer_interval = 0;
202 int i;
203
204 mutex_lock(&sessions_mutex);
205
206 transport = lttng_transport_find(transport_name);
207 if (!transport) {
208 printk(KERN_WARNING "LTTng transport %s not found\n",
209 transport_name);
210 goto notransport;
211 }
212 if (!try_module_get(transport->owner)) {
213 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
214 goto notransport;
215 }
216
217 trigger_group = lttng_kvzalloc(sizeof(struct lttng_trigger_group),
218 GFP_KERNEL);
219 if (!trigger_group)
220 goto nomem;
221
222 trigger_group->ops = &transport->ops;
223 trigger_group->chan = transport->ops.channel_create(transport_name,
224 trigger_group, NULL, subbuf_size, num_subbuf,
225 switch_timer_interval, read_timer_interval);
226 if (!trigger_group->chan)
227 goto create_error;
228
229 trigger_group->transport = transport;
230 INIT_LIST_HEAD(&trigger_group->enablers_head);
231 INIT_LIST_HEAD(&trigger_group->triggers_head);
232 for (i = 0; i < LTTNG_TRIGGER_HT_SIZE; i++)
233 INIT_HLIST_HEAD(&trigger_group->triggers_ht.table[i]);
234
235 list_add(&trigger_group->node, &trigger_groups);
236 mutex_unlock(&sessions_mutex);
237
238 return trigger_group;
239
240 create_error:
241 lttng_kvfree(trigger_group);
242 nomem:
243 if (transport)
244 module_put(transport->owner);
245 notransport:
246 mutex_unlock(&sessions_mutex);
247 return NULL;
248 }
249
250 void metadata_cache_destroy(struct kref *kref)
251 {
252 struct lttng_metadata_cache *cache =
253 container_of(kref, struct lttng_metadata_cache, refcount);
254 vfree(cache->data);
255 kfree(cache);
256 }
257
258 void lttng_session_destroy(struct lttng_session *session)
259 {
260 struct lttng_channel *chan, *tmpchan;
261 struct lttng_event *event, *tmpevent;
262 struct lttng_metadata_stream *metadata_stream;
263 struct lttng_event_enabler *event_enabler, *tmp_event_enabler;
264 int ret;
265
266 mutex_lock(&sessions_mutex);
267 WRITE_ONCE(session->active, 0);
268 list_for_each_entry(chan, &session->chan, list) {
269 ret = lttng_syscalls_unregister_event(chan);
270 WARN_ON(ret);
271 }
272 list_for_each_entry(event, &session->events, list) {
273 ret = _lttng_event_unregister(event);
274 WARN_ON(ret);
275 }
276 synchronize_trace(); /* Wait for in-flight events to complete */
277 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
278 &session->enablers_head, node)
279 lttng_event_enabler_destroy(event_enabler);
280 list_for_each_entry_safe(event, tmpevent, &session->events, list)
281 _lttng_event_destroy(event);
282 list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
283 BUG_ON(chan->channel_type == METADATA_CHANNEL);
284 _lttng_channel_destroy(chan);
285 }
286 list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
287 _lttng_metadata_channel_hangup(metadata_stream);
288 lttng_id_tracker_destroy(&session->pid_tracker, false);
289 lttng_id_tracker_destroy(&session->vpid_tracker, false);
290 lttng_id_tracker_destroy(&session->uid_tracker, false);
291 lttng_id_tracker_destroy(&session->vuid_tracker, false);
292 lttng_id_tracker_destroy(&session->gid_tracker, false);
293 lttng_id_tracker_destroy(&session->vgid_tracker, false);
294 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
295 list_del(&session->list);
296 mutex_unlock(&sessions_mutex);
297 lttng_kvfree(session);
298 }
299
300 void lttng_trigger_group_destroy(struct lttng_trigger_group *trigger_group)
301 {
302 struct lttng_trigger_enabler *trigger_enabler, *tmp_trigger_enabler;
303 struct lttng_trigger *trigger, *tmptrigger;
304 int ret;
305
306 if (!trigger_group)
307 return;
308
309 mutex_lock(&sessions_mutex);
310
311 ret = lttng_syscalls_unregister_trigger(trigger_group);
312 WARN_ON(ret);
313
314 list_for_each_entry_safe(trigger, tmptrigger,
315 &trigger_group->triggers_head, list) {
316 ret = _lttng_trigger_unregister(trigger);
317 WARN_ON(ret);
318 }
319
320 synchronize_trace(); /* Wait for in-flight triggers to complete */
321
322 irq_work_sync(&trigger_group->wakeup_pending);
323
324 list_for_each_entry_safe(trigger_enabler, tmp_trigger_enabler,
325 &trigger_group->enablers_head, node)
326 lttng_trigger_enabler_destroy(trigger_enabler);
327
328 list_for_each_entry_safe(trigger, tmptrigger,
329 &trigger_group->triggers_head, list)
330 _lttng_trigger_destroy(trigger);
331
332 trigger_group->ops->channel_destroy(trigger_group->chan);
333 module_put(trigger_group->transport->owner);
334 list_del(&trigger_group->node);
335 mutex_unlock(&sessions_mutex);
336 lttng_kvfree(trigger_group);
337 }
338
339 int lttng_session_statedump(struct lttng_session *session)
340 {
341 int ret;
342
343 mutex_lock(&sessions_mutex);
344 ret = lttng_statedump_start(session);
345 mutex_unlock(&sessions_mutex);
346 return ret;
347 }
348
349 int lttng_session_enable(struct lttng_session *session)
350 {
351 int ret = 0;
352 struct lttng_channel *chan;
353
354 mutex_lock(&sessions_mutex);
355 if (session->active) {
356 ret = -EBUSY;
357 goto end;
358 }
359
360 /* Set transient enabler state to "enabled" */
361 session->tstate = 1;
362
363 /* We need to sync enablers with session before activation. */
364 lttng_session_sync_event_enablers(session);
365
366 /*
367 * Snapshot the number of events per channel to know the type of header
368 * we need to use.
369 */
370 list_for_each_entry(chan, &session->chan, list) {
371 if (chan->header_type)
372 continue; /* don't change it if session stop/restart */
373 if (chan->free_event_id < 31)
374 chan->header_type = 1; /* compact */
375 else
376 chan->header_type = 2; /* large */
377 }
378
379 /* Clear each stream's quiescent state. */
380 list_for_each_entry(chan, &session->chan, list) {
381 if (chan->channel_type != METADATA_CHANNEL)
382 lib_ring_buffer_clear_quiescent_channel(chan->chan);
383 }
384
385 WRITE_ONCE(session->active, 1);
386 WRITE_ONCE(session->been_active, 1);
387 ret = _lttng_session_metadata_statedump(session);
388 if (ret) {
389 WRITE_ONCE(session->active, 0);
390 goto end;
391 }
392 ret = lttng_statedump_start(session);
393 if (ret)
394 WRITE_ONCE(session->active, 0);
395 end:
396 mutex_unlock(&sessions_mutex);
397 return ret;
398 }
399
400 int lttng_session_disable(struct lttng_session *session)
401 {
402 int ret = 0;
403 struct lttng_channel *chan;
404
405 mutex_lock(&sessions_mutex);
406 if (!session->active) {
407 ret = -EBUSY;
408 goto end;
409 }
410 WRITE_ONCE(session->active, 0);
411
412 /* Set transient enabler state to "disabled" */
413 session->tstate = 0;
414 lttng_session_sync_event_enablers(session);
415
416 /* Set each stream's quiescent state. */
417 list_for_each_entry(chan, &session->chan, list) {
418 if (chan->channel_type != METADATA_CHANNEL)
419 lib_ring_buffer_set_quiescent_channel(chan->chan);
420 }
421 end:
422 mutex_unlock(&sessions_mutex);
423 return ret;
424 }
425
426 int lttng_session_metadata_regenerate(struct lttng_session *session)
427 {
428 int ret = 0;
429 struct lttng_channel *chan;
430 struct lttng_event *event;
431 struct lttng_metadata_cache *cache = session->metadata_cache;
432 struct lttng_metadata_stream *stream;
433
434 mutex_lock(&sessions_mutex);
435 if (!session->active) {
436 ret = -EBUSY;
437 goto end;
438 }
439
440 mutex_lock(&cache->lock);
441 memset(cache->data, 0, cache->cache_alloc);
442 cache->metadata_written = 0;
443 cache->version++;
444 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list) {
445 stream->metadata_out = 0;
446 stream->metadata_in = 0;
447 }
448 mutex_unlock(&cache->lock);
449
450 session->metadata_dumped = 0;
451 list_for_each_entry(chan, &session->chan, list) {
452 chan->metadata_dumped = 0;
453 }
454
455 list_for_each_entry(event, &session->events, list) {
456 event->metadata_dumped = 0;
457 }
458
459 ret = _lttng_session_metadata_statedump(session);
460
461 end:
462 mutex_unlock(&sessions_mutex);
463 return ret;
464 }
465
466 int lttng_channel_enable(struct lttng_channel *channel)
467 {
468 int ret = 0;
469
470 mutex_lock(&sessions_mutex);
471 if (channel->channel_type == METADATA_CHANNEL) {
472 ret = -EPERM;
473 goto end;
474 }
475 if (channel->enabled) {
476 ret = -EEXIST;
477 goto end;
478 }
479 /* Set transient enabler state to "enabled" */
480 channel->tstate = 1;
481 lttng_session_sync_event_enablers(channel->session);
482 /* Set atomically the state to "enabled" */
483 WRITE_ONCE(channel->enabled, 1);
484 end:
485 mutex_unlock(&sessions_mutex);
486 return ret;
487 }
488
489 int lttng_channel_disable(struct lttng_channel *channel)
490 {
491 int ret = 0;
492
493 mutex_lock(&sessions_mutex);
494 if (channel->channel_type == METADATA_CHANNEL) {
495 ret = -EPERM;
496 goto end;
497 }
498 if (!channel->enabled) {
499 ret = -EEXIST;
500 goto end;
501 }
502 /* Set atomically the state to "disabled" */
503 WRITE_ONCE(channel->enabled, 0);
504 /* Set transient enabler state to "enabled" */
505 channel->tstate = 0;
506 lttng_session_sync_event_enablers(channel->session);
507 end:
508 mutex_unlock(&sessions_mutex);
509 return ret;
510 }
511
512 int lttng_event_enable(struct lttng_event *event)
513 {
514 int ret = 0;
515
516 mutex_lock(&sessions_mutex);
517 if (event->chan->channel_type == METADATA_CHANNEL) {
518 ret = -EPERM;
519 goto end;
520 }
521 if (event->enabled) {
522 ret = -EEXIST;
523 goto end;
524 }
525 switch (event->instrumentation) {
526 case LTTNG_KERNEL_TRACEPOINT:
527 case LTTNG_KERNEL_SYSCALL:
528 ret = -EINVAL;
529 break;
530 case LTTNG_KERNEL_KPROBE:
531 case LTTNG_KERNEL_FUNCTION:
532 case LTTNG_KERNEL_UPROBE:
533 case LTTNG_KERNEL_NOOP:
534 WRITE_ONCE(event->enabled, 1);
535 break;
536 case LTTNG_KERNEL_KRETPROBE:
537 ret = lttng_kretprobes_event_enable_state(event, 1);
538 break;
539 default:
540 WARN_ON_ONCE(1);
541 ret = -EINVAL;
542 }
543 end:
544 mutex_unlock(&sessions_mutex);
545 return ret;
546 }
547
548 int lttng_event_disable(struct lttng_event *event)
549 {
550 int ret = 0;
551
552 mutex_lock(&sessions_mutex);
553 if (event->chan->channel_type == METADATA_CHANNEL) {
554 ret = -EPERM;
555 goto end;
556 }
557 if (!event->enabled) {
558 ret = -EEXIST;
559 goto end;
560 }
561 switch (event->instrumentation) {
562 case LTTNG_KERNEL_TRACEPOINT:
563 case LTTNG_KERNEL_SYSCALL:
564 ret = -EINVAL;
565 break;
566 case LTTNG_KERNEL_KPROBE:
567 case LTTNG_KERNEL_FUNCTION:
568 case LTTNG_KERNEL_UPROBE:
569 case LTTNG_KERNEL_NOOP:
570 WRITE_ONCE(event->enabled, 0);
571 break;
572 case LTTNG_KERNEL_KRETPROBE:
573 ret = lttng_kretprobes_event_enable_state(event, 0);
574 break;
575 default:
576 WARN_ON_ONCE(1);
577 ret = -EINVAL;
578 }
579 end:
580 mutex_unlock(&sessions_mutex);
581 return ret;
582 }
583
584 int lttng_trigger_enable(struct lttng_trigger *trigger)
585 {
586 int ret = 0;
587
588 mutex_lock(&sessions_mutex);
589 if (trigger->enabled) {
590 ret = -EEXIST;
591 goto end;
592 }
593 switch (trigger->instrumentation) {
594 case LTTNG_KERNEL_TRACEPOINT:
595 case LTTNG_KERNEL_SYSCALL:
596 ret = -EINVAL;
597 break;
598 case LTTNG_KERNEL_KPROBE:
599 case LTTNG_KERNEL_UPROBE:
600 WRITE_ONCE(trigger->enabled, 1);
601 break;
602 case LTTNG_KERNEL_FUNCTION:
603 case LTTNG_KERNEL_NOOP:
604 case LTTNG_KERNEL_KRETPROBE:
605 default:
606 WARN_ON_ONCE(1);
607 ret = -EINVAL;
608 }
609 end:
610 mutex_unlock(&sessions_mutex);
611 return ret;
612 }
613
614 int lttng_trigger_disable(struct lttng_trigger *trigger)
615 {
616 int ret = 0;
617
618 mutex_lock(&sessions_mutex);
619 if (!trigger->enabled) {
620 ret = -EEXIST;
621 goto end;
622 }
623 switch (trigger->instrumentation) {
624 case LTTNG_KERNEL_TRACEPOINT:
625 case LTTNG_KERNEL_SYSCALL:
626 ret = -EINVAL;
627 break;
628 case LTTNG_KERNEL_KPROBE:
629 case LTTNG_KERNEL_UPROBE:
630 WRITE_ONCE(trigger->enabled, 0);
631 break;
632 case LTTNG_KERNEL_FUNCTION:
633 case LTTNG_KERNEL_NOOP:
634 case LTTNG_KERNEL_KRETPROBE:
635 default:
636 WARN_ON_ONCE(1);
637 ret = -EINVAL;
638 }
639 end:
640 mutex_unlock(&sessions_mutex);
641 return ret;
642 }
643
644 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
645 const char *transport_name,
646 void *buf_addr,
647 size_t subbuf_size, size_t num_subbuf,
648 unsigned int switch_timer_interval,
649 unsigned int read_timer_interval,
650 enum channel_type channel_type)
651 {
652 struct lttng_channel *chan;
653 struct lttng_transport *transport = NULL;
654
655 mutex_lock(&sessions_mutex);
656 if (session->been_active && channel_type != METADATA_CHANNEL)
657 goto active; /* Refuse to add channel to active session */
658 transport = lttng_transport_find(transport_name);
659 if (!transport) {
660 printk(KERN_WARNING "LTTng transport %s not found\n",
661 transport_name);
662 goto notransport;
663 }
664 if (!try_module_get(transport->owner)) {
665 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
666 goto notransport;
667 }
668 chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL);
669 if (!chan)
670 goto nomem;
671 chan->session = session;
672 chan->id = session->free_chan_id++;
673 chan->ops = &transport->ops;
674 /*
675 * Note: the channel creation op already writes into the packet
676 * headers. Therefore the "chan" information used as input
677 * should be already accessible.
678 */
679 chan->chan = transport->ops.channel_create(transport_name,
680 chan, buf_addr, subbuf_size, num_subbuf,
681 switch_timer_interval, read_timer_interval);
682 if (!chan->chan)
683 goto create_error;
684 chan->tstate = 1;
685 chan->enabled = 1;
686 chan->transport = transport;
687 chan->channel_type = channel_type;
688 list_add(&chan->list, &session->chan);
689 mutex_unlock(&sessions_mutex);
690 return chan;
691
692 create_error:
693 kfree(chan);
694 nomem:
695 if (transport)
696 module_put(transport->owner);
697 notransport:
698 active:
699 mutex_unlock(&sessions_mutex);
700 return NULL;
701 }
702
703 /*
704 * Only used internally at session destruction for per-cpu channels, and
705 * when metadata channel is released.
706 * Needs to be called with sessions mutex held.
707 */
708 static
709 void _lttng_channel_destroy(struct lttng_channel *chan)
710 {
711 chan->ops->channel_destroy(chan->chan);
712 module_put(chan->transport->owner);
713 list_del(&chan->list);
714 lttng_destroy_context(chan->ctx);
715 kfree(chan);
716 }
717
718 void lttng_metadata_channel_destroy(struct lttng_channel *chan)
719 {
720 BUG_ON(chan->channel_type != METADATA_CHANNEL);
721
722 /* Protect the metadata cache with the sessions_mutex. */
723 mutex_lock(&sessions_mutex);
724 _lttng_channel_destroy(chan);
725 mutex_unlock(&sessions_mutex);
726 }
727 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
728
729 static
730 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
731 {
732 stream->finalized = 1;
733 wake_up_interruptible(&stream->read_wait);
734 }
735
736 /*
737 * Supports event creation while tracing session is active.
738 * Needs to be called with sessions mutex held.
739 */
740 struct lttng_event *_lttng_event_create(struct lttng_channel *chan,
741 struct lttng_kernel_event *event_param,
742 void *filter,
743 const struct lttng_event_desc *event_desc,
744 enum lttng_kernel_instrumentation itype)
745 {
746 struct lttng_session *session = chan->session;
747 struct lttng_event *event;
748 const char *event_name;
749 struct hlist_head *head;
750 int ret;
751
752 if (chan->free_event_id == -1U) {
753 ret = -EMFILE;
754 goto full;
755 }
756
757 switch (itype) {
758 case LTTNG_KERNEL_TRACEPOINT:
759 event_name = event_desc->name;
760 break;
761 case LTTNG_KERNEL_KPROBE:
762 case LTTNG_KERNEL_UPROBE:
763 case LTTNG_KERNEL_KRETPROBE:
764 case LTTNG_KERNEL_FUNCTION:
765 case LTTNG_KERNEL_NOOP:
766 case LTTNG_KERNEL_SYSCALL:
767 event_name = event_param->name;
768 break;
769 default:
770 WARN_ON_ONCE(1);
771 ret = -EINVAL;
772 goto type_error;
773 }
774
775 head = utils_borrow_hash_table_bucket(session->events_ht.table,
776 LTTNG_EVENT_HT_SIZE, event_name);
777 lttng_hlist_for_each_entry(event, head, hlist) {
778 WARN_ON_ONCE(!event->desc);
779 if (!strncmp(event->desc->name, event_name,
780 LTTNG_KERNEL_SYM_NAME_LEN - 1)
781 && chan == event->chan) {
782 ret = -EEXIST;
783 goto exist;
784 }
785 }
786
787 event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
788 if (!event) {
789 ret = -ENOMEM;
790 goto cache_error;
791 }
792 event->chan = chan;
793 event->filter = filter;
794 event->id = chan->free_event_id++;
795 event->instrumentation = itype;
796 event->evtype = LTTNG_TYPE_EVENT;
797 INIT_LIST_HEAD(&event->bytecode_runtime_head);
798 INIT_LIST_HEAD(&event->enablers_ref_head);
799
800 switch (itype) {
801 case LTTNG_KERNEL_TRACEPOINT:
802 /* Event will be enabled by enabler sync. */
803 event->enabled = 0;
804 event->registered = 0;
805 event->desc = lttng_event_desc_get(event_name);
806 if (!event->desc) {
807 ret = -ENOENT;
808 goto register_error;
809 }
810 /* Populate lttng_event structure before event registration. */
811 smp_wmb();
812 break;
813 case LTTNG_KERNEL_KPROBE:
814 /*
815 * Needs to be explicitly enabled after creation, since
816 * we may want to apply filters.
817 */
818 event->enabled = 0;
819 event->registered = 1;
820 /*
821 * Populate lttng_event structure before event
822 * registration.
823 */
824 smp_wmb();
825 ret = lttng_kprobes_register_event(event_name,
826 event_param->u.kprobe.symbol_name,
827 event_param->u.kprobe.offset,
828 event_param->u.kprobe.addr,
829 event);
830 if (ret) {
831 ret = -EINVAL;
832 goto register_error;
833 }
834 ret = try_module_get(event->desc->owner);
835 WARN_ON_ONCE(!ret);
836 break;
837 case LTTNG_KERNEL_KRETPROBE:
838 {
839 struct lttng_event *event_return;
840
841 /* kretprobe defines 2 events */
842 /*
843 * Needs to be explicitly enabled after creation, since
844 * we may want to apply filters.
845 */
846 event->enabled = 0;
847 event->registered = 1;
848 event_return =
849 kmem_cache_zalloc(event_cache, GFP_KERNEL);
850 if (!event_return) {
851 ret = -ENOMEM;
852 goto register_error;
853 }
854 event_return->chan = chan;
855 event_return->filter = filter;
856 event_return->id = chan->free_event_id++;
857 event_return->enabled = 0;
858 event_return->registered = 1;
859 event_return->instrumentation = itype;
860 /*
861 * Populate lttng_event structure before kretprobe registration.
862 */
863 smp_wmb();
864 ret = lttng_kretprobes_register(event_name,
865 event_param->u.kretprobe.symbol_name,
866 event_param->u.kretprobe.offset,
867 event_param->u.kretprobe.addr,
868 event, event_return);
869 if (ret) {
870 kmem_cache_free(event_cache, event_return);
871 ret = -EINVAL;
872 goto register_error;
873 }
874 /* Take 2 refs on the module: one per event. */
875 ret = try_module_get(event->desc->owner);
876 WARN_ON_ONCE(!ret);
877 ret = try_module_get(event->desc->owner);
878 WARN_ON_ONCE(!ret);
879 ret = _lttng_event_metadata_statedump(chan->session, chan,
880 event_return);
881 WARN_ON_ONCE(ret > 0);
882 if (ret) {
883 kmem_cache_free(event_cache, event_return);
884 module_put(event->desc->owner);
885 module_put(event->desc->owner);
886 goto statedump_error;
887 }
888 list_add(&event_return->list, &chan->session->events);
889 break;
890 }
891 case LTTNG_KERNEL_FUNCTION:
892 /*
893 * Needs to be explicitly enabled after creation, since
894 * we may want to apply filters.
895 */
896 event->enabled = 0;
897 event->registered = 1;
898 /*
899 * Populate lttng_event structure before event
900 * registration.
901 */
902 smp_wmb();
903 ret = lttng_ftrace_register(event_name,
904 event_param->u.ftrace.symbol_name,
905 event);
906 if (ret) {
907 goto register_error;
908 }
909 ret = try_module_get(event->desc->owner);
910 WARN_ON_ONCE(!ret);
911 break;
912 case LTTNG_KERNEL_NOOP:
913 case LTTNG_KERNEL_SYSCALL:
914 /*
915 * Needs to be explicitly enabled after creation, since
916 * we may want to apply filters.
917 */
918 event->enabled = 0;
919 event->registered = 0;
920 event->desc = event_desc;
921 if (!event->desc) {
922 ret = -EINVAL;
923 goto register_error;
924 }
925 break;
926 case LTTNG_KERNEL_UPROBE:
927 /*
928 * Needs to be explicitly enabled after creation, since
929 * we may want to apply filters.
930 */
931 event->enabled = 0;
932 event->registered = 1;
933
934 /*
935 * Populate lttng_event structure before event
936 * registration.
937 */
938 smp_wmb();
939
940 ret = lttng_uprobes_register_event(event_param->name,
941 event_param->u.uprobe.fd,
942 event);
943 if (ret)
944 goto register_error;
945 ret = try_module_get(event->desc->owner);
946 WARN_ON_ONCE(!ret);
947 break;
948 default:
949 WARN_ON_ONCE(1);
950 ret = -EINVAL;
951 goto register_error;
952 }
953 ret = _lttng_event_metadata_statedump(chan->session, chan, event);
954 WARN_ON_ONCE(ret > 0);
955 if (ret) {
956 goto statedump_error;
957 }
958 hlist_add_head(&event->hlist, head);
959 list_add(&event->list, &chan->session->events);
960 return event;
961
962 statedump_error:
963 /* If a statedump error occurs, events will not be readable. */
964 register_error:
965 kmem_cache_free(event_cache, event);
966 cache_error:
967 exist:
968 type_error:
969 full:
970 return ERR_PTR(ret);
971 }
972
973 static
974 void lttng_trigger_send_notification(struct lttng_trigger *trigger)
975 {
976 struct lttng_trigger_group *trigger_group = trigger->group;
977 struct lib_ring_buffer_ctx ctx;
978 int ret;
979
980 if (unlikely(!READ_ONCE(trigger->enabled)))
981 return;
982
983 lib_ring_buffer_ctx_init(&ctx, trigger_group->chan, NULL, sizeof(trigger->id),
984 lttng_alignof(trigger->id), -1);
985 ret = trigger_group->ops->event_reserve(&ctx, 0);
986 if (ret < 0) {
987 //TODO: error handling with counter maps
988 //silently drop for now. WARN_ON_ONCE(1);
989 return;
990 }
991 lib_ring_buffer_align_ctx(&ctx, lttng_alignof(trigger->id));
992 trigger_group->ops->event_write(&ctx, &trigger->id, sizeof(trigger->id));
993 trigger_group->ops->event_commit(&ctx);
994 irq_work_queue(&trigger_group->wakeup_pending);
995 }
996
997 struct lttng_trigger *_lttng_trigger_create(
998 const struct lttng_event_desc *event_desc,
999 uint64_t id, struct lttng_trigger_group *trigger_group,
1000 struct lttng_kernel_trigger *trigger_param, void *filter,
1001 enum lttng_kernel_instrumentation itype)
1002 {
1003 struct lttng_trigger *trigger;
1004 const char *event_name;
1005 struct hlist_head *head;
1006 int ret;
1007
1008 switch (itype) {
1009 case LTTNG_KERNEL_TRACEPOINT:
1010 event_name = event_desc->name;
1011 break;
1012 case LTTNG_KERNEL_KPROBE:
1013 case LTTNG_KERNEL_UPROBE:
1014 case LTTNG_KERNEL_SYSCALL:
1015 event_name = trigger_param->name;
1016 break;
1017 case LTTNG_KERNEL_KRETPROBE:
1018 case LTTNG_KERNEL_FUNCTION:
1019 case LTTNG_KERNEL_NOOP:
1020 default:
1021 WARN_ON_ONCE(1);
1022 ret = -EINVAL;
1023 goto type_error;
1024 }
1025
1026 head = utils_borrow_hash_table_bucket(trigger_group->triggers_ht.table,
1027 LTTNG_TRIGGER_HT_SIZE, event_name);
1028 lttng_hlist_for_each_entry(trigger, head, hlist) {
1029 WARN_ON_ONCE(!trigger->desc);
1030 if (!strncmp(trigger->desc->name, event_name,
1031 LTTNG_KERNEL_SYM_NAME_LEN - 1)
1032 && trigger_group == trigger->group
1033 && id == trigger->id) {
1034 ret = -EEXIST;
1035 goto exist;
1036 }
1037 }
1038
1039 trigger = kmem_cache_zalloc(trigger_cache, GFP_KERNEL);
1040 if (!trigger) {
1041 ret = -ENOMEM;
1042 goto cache_error;
1043 }
1044 trigger->group = trigger_group;
1045 trigger->id = id;
1046 trigger->filter = filter;
1047 trigger->instrumentation = itype;
1048 trigger->evtype = LTTNG_TYPE_EVENT;
1049 trigger->send_notification = lttng_trigger_send_notification;
1050 INIT_LIST_HEAD(&trigger->bytecode_runtime_head);
1051 INIT_LIST_HEAD(&trigger->enablers_ref_head);
1052
1053 switch (itype) {
1054 case LTTNG_KERNEL_TRACEPOINT:
1055 /* Event will be enabled by enabler sync. */
1056 trigger->enabled = 0;
1057 trigger->registered = 0;
1058 trigger->desc = lttng_event_desc_get(event_name);
1059 if (!trigger->desc) {
1060 ret = -ENOENT;
1061 goto register_error;
1062 }
1063 /* Populate lttng_trigger structure before event registration. */
1064 smp_wmb();
1065 break;
1066 case LTTNG_KERNEL_KPROBE:
1067 /*
1068 * Needs to be explicitly enabled after creation, since
1069 * we may want to apply filters.
1070 */
1071 trigger->enabled = 0;
1072 trigger->registered = 1;
1073 /*
1074 * Populate lttng_trigger structure before event
1075 * registration.
1076 */
1077 smp_wmb();
1078 ret = lttng_kprobes_register_trigger(
1079 trigger_param->u.kprobe.symbol_name,
1080 trigger_param->u.kprobe.offset,
1081 trigger_param->u.kprobe.addr,
1082 trigger);
1083 if (ret) {
1084 ret = -EINVAL;
1085 goto register_error;
1086 }
1087 ret = try_module_get(trigger->desc->owner);
1088 WARN_ON_ONCE(!ret);
1089 break;
1090 case LTTNG_KERNEL_NOOP:
1091 case LTTNG_KERNEL_SYSCALL:
1092 /*
1093 * Needs to be explicitly enabled after creation, since
1094 * we may want to apply filters.
1095 */
1096 trigger->enabled = 0;
1097 trigger->registered = 0;
1098 trigger->desc = event_desc;
1099 if (!trigger->desc) {
1100 ret = -EINVAL;
1101 goto register_error;
1102 }
1103 break;
1104 case LTTNG_KERNEL_UPROBE:
1105 /*
1106 * Needs to be explicitly enabled after creation, since
1107 * we may want to apply filters.
1108 */
1109 trigger->enabled = 0;
1110 trigger->registered = 1;
1111
1112 /*
1113 * Populate lttng_trigger structure before trigger
1114 * registration.
1115 */
1116 smp_wmb();
1117
1118 ret = lttng_uprobes_register_trigger(trigger_param->name,
1119 trigger_param->u.uprobe.fd,
1120 trigger);
1121 if (ret)
1122 goto register_error;
1123 ret = try_module_get(trigger->desc->owner);
1124 WARN_ON_ONCE(!ret);
1125 break;
1126 case LTTNG_KERNEL_KRETPROBE:
1127 case LTTNG_KERNEL_FUNCTION:
1128 default:
1129 WARN_ON_ONCE(1);
1130 ret = -EINVAL;
1131 goto register_error;
1132 }
1133
1134 list_add(&trigger->list, &trigger_group->triggers_head);
1135 hlist_add_head(&trigger->hlist, head);
1136 return trigger;
1137
1138 register_error:
1139 kmem_cache_free(trigger_cache, trigger);
1140 cache_error:
1141 exist:
1142 type_error:
1143 return ERR_PTR(ret);
1144 }
1145
1146 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
1147 struct lttng_kernel_event *event_param,
1148 void *filter,
1149 const struct lttng_event_desc *event_desc,
1150 enum lttng_kernel_instrumentation itype)
1151 {
1152 struct lttng_event *event;
1153
1154 mutex_lock(&sessions_mutex);
1155 event = _lttng_event_create(chan, event_param, filter, event_desc,
1156 itype);
1157 mutex_unlock(&sessions_mutex);
1158 return event;
1159 }
1160
1161 struct lttng_trigger *lttng_trigger_create(
1162 const struct lttng_event_desc *event_desc,
1163 uint64_t id, struct lttng_trigger_group *trigger_group,
1164 struct lttng_kernel_trigger *trigger_param, void *filter,
1165 enum lttng_kernel_instrumentation itype)
1166 {
1167 struct lttng_trigger *trigger;
1168
1169 mutex_lock(&sessions_mutex);
1170 trigger = _lttng_trigger_create(event_desc, id, trigger_group,
1171 trigger_param, filter, itype);
1172 mutex_unlock(&sessions_mutex);
1173 return trigger;
1174 }
1175
1176 /* Only used for tracepoints for now. */
1177 static
1178 void register_event(struct lttng_event *event)
1179 {
1180 const struct lttng_event_desc *desc;
1181 int ret = -EINVAL;
1182
1183 if (event->registered)
1184 return;
1185
1186 desc = event->desc;
1187 switch (event->instrumentation) {
1188 case LTTNG_KERNEL_TRACEPOINT:
1189 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
1190 desc->probe_callback,
1191 event);
1192 break;
1193 case LTTNG_KERNEL_SYSCALL:
1194 ret = lttng_syscall_filter_enable_event(event->chan,
1195 desc->name);
1196 break;
1197 case LTTNG_KERNEL_KPROBE:
1198 case LTTNG_KERNEL_UPROBE:
1199 case LTTNG_KERNEL_KRETPROBE:
1200 case LTTNG_KERNEL_FUNCTION:
1201 case LTTNG_KERNEL_NOOP:
1202 ret = 0;
1203 break;
1204 default:
1205 WARN_ON_ONCE(1);
1206 }
1207 if (!ret)
1208 event->registered = 1;
1209 }
1210
1211 /*
1212 * Only used internally at session destruction.
1213 */
1214 int _lttng_event_unregister(struct lttng_event *event)
1215 {
1216 const struct lttng_event_desc *desc;
1217 int ret = -EINVAL;
1218
1219 if (!event->registered)
1220 return 0;
1221
1222 desc = event->desc;
1223 switch (event->instrumentation) {
1224 case LTTNG_KERNEL_TRACEPOINT:
1225 ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname,
1226 event->desc->probe_callback,
1227 event);
1228 break;
1229 case LTTNG_KERNEL_KPROBE:
1230 lttng_kprobes_unregister_event(event);
1231 ret = 0;
1232 break;
1233 case LTTNG_KERNEL_KRETPROBE:
1234 lttng_kretprobes_unregister(event);
1235 ret = 0;
1236 break;
1237 case LTTNG_KERNEL_FUNCTION:
1238 lttng_ftrace_unregister(event);
1239 ret = 0;
1240 break;
1241 case LTTNG_KERNEL_SYSCALL:
1242 ret = lttng_syscall_filter_disable_event(event->chan,
1243 desc->name);
1244 break;
1245 case LTTNG_KERNEL_NOOP:
1246 ret = 0;
1247 break;
1248 case LTTNG_KERNEL_UPROBE:
1249 lttng_uprobes_unregister_event(event);
1250 ret = 0;
1251 break;
1252 default:
1253 WARN_ON_ONCE(1);
1254 }
1255 if (!ret)
1256 event->registered = 0;
1257 return ret;
1258 }
1259
1260 /* Only used for tracepoints for now. */
1261 static
1262 void register_trigger(struct lttng_trigger *trigger)
1263 {
1264 const struct lttng_event_desc *desc;
1265 int ret = -EINVAL;
1266
1267 if (trigger->registered)
1268 return;
1269
1270 desc = trigger->desc;
1271 switch (trigger->instrumentation) {
1272 case LTTNG_KERNEL_TRACEPOINT:
1273 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
1274 desc->trigger_callback,
1275 trigger);
1276 break;
1277 case LTTNG_KERNEL_SYSCALL:
1278 ret = lttng_syscall_filter_enable_trigger(trigger);
1279 break;
1280 case LTTNG_KERNEL_KPROBE:
1281 case LTTNG_KERNEL_UPROBE:
1282 ret = 0;
1283 break;
1284 case LTTNG_KERNEL_KRETPROBE:
1285 case LTTNG_KERNEL_FUNCTION:
1286 case LTTNG_KERNEL_NOOP:
1287 default:
1288 WARN_ON_ONCE(1);
1289 }
1290 if (!ret)
1291 trigger->registered = 1;
1292 }
1293
1294 static
1295 int _lttng_trigger_unregister(struct lttng_trigger *trigger)
1296 {
1297 const struct lttng_event_desc *desc;
1298 int ret = -EINVAL;
1299
1300 if (!trigger->registered)
1301 return 0;
1302
1303 desc = trigger->desc;
1304 switch (trigger->instrumentation) {
1305 case LTTNG_KERNEL_TRACEPOINT:
1306 ret = lttng_wrapper_tracepoint_probe_unregister(trigger->desc->kname,
1307 trigger->desc->trigger_callback,
1308 trigger);
1309 break;
1310 case LTTNG_KERNEL_KPROBE:
1311 lttng_kprobes_unregister_trigger(trigger);
1312 ret = 0;
1313 break;
1314 case LTTNG_KERNEL_UPROBE:
1315 lttng_uprobes_unregister_trigger(trigger);
1316 ret = 0;
1317 break;
1318 case LTTNG_KERNEL_SYSCALL:
1319 ret = lttng_syscall_filter_disable_trigger(trigger);
1320 break;
1321 case LTTNG_KERNEL_KRETPROBE:
1322 case LTTNG_KERNEL_FUNCTION:
1323 case LTTNG_KERNEL_NOOP:
1324 default:
1325 WARN_ON_ONCE(1);
1326 }
1327 if (!ret)
1328 trigger->registered = 0;
1329 return ret;
1330 }
1331
1332 /*
1333 * Only used internally at session destruction.
1334 */
1335 static
1336 void _lttng_event_destroy(struct lttng_event *event)
1337 {
1338 switch (event->instrumentation) {
1339 case LTTNG_KERNEL_TRACEPOINT:
1340 lttng_event_desc_put(event->desc);
1341 break;
1342 case LTTNG_KERNEL_KPROBE:
1343 module_put(event->desc->owner);
1344 lttng_kprobes_destroy_event_private(event);
1345 break;
1346 case LTTNG_KERNEL_KRETPROBE:
1347 module_put(event->desc->owner);
1348 lttng_kretprobes_destroy_private(event);
1349 break;
1350 case LTTNG_KERNEL_FUNCTION:
1351 module_put(event->desc->owner);
1352 lttng_ftrace_destroy_private(event);
1353 break;
1354 case LTTNG_KERNEL_NOOP:
1355 case LTTNG_KERNEL_SYSCALL:
1356 break;
1357 case LTTNG_KERNEL_UPROBE:
1358 module_put(event->desc->owner);
1359 lttng_uprobes_destroy_event_private(event);
1360 break;
1361 default:
1362 WARN_ON_ONCE(1);
1363 }
1364 list_del(&event->list);
1365 lttng_destroy_context(event->ctx);
1366 kmem_cache_free(event_cache, event);
1367 }
1368
1369 /*
1370 * Only used internally at session destruction.
1371 */
1372 static
1373 void _lttng_trigger_destroy(struct lttng_trigger *trigger)
1374 {
1375 switch (trigger->instrumentation) {
1376 case LTTNG_KERNEL_TRACEPOINT:
1377 lttng_event_desc_put(trigger->desc);
1378 break;
1379 case LTTNG_KERNEL_KPROBE:
1380 module_put(trigger->desc->owner);
1381 lttng_kprobes_destroy_trigger_private(trigger);
1382 break;
1383 case LTTNG_KERNEL_NOOP:
1384 case LTTNG_KERNEL_SYSCALL:
1385 break;
1386 case LTTNG_KERNEL_UPROBE:
1387 module_put(trigger->desc->owner);
1388 lttng_uprobes_destroy_trigger_private(trigger);
1389 break;
1390 case LTTNG_KERNEL_KRETPROBE:
1391 case LTTNG_KERNEL_FUNCTION:
1392 default:
1393 WARN_ON_ONCE(1);
1394 }
1395 list_del(&trigger->list);
1396 kmem_cache_free(trigger_cache, trigger);
1397 }
1398
1399 struct lttng_id_tracker *get_tracker(struct lttng_session *session,
1400 enum tracker_type tracker_type)
1401 {
1402 switch (tracker_type) {
1403 case TRACKER_PID:
1404 return &session->pid_tracker;
1405 case TRACKER_VPID:
1406 return &session->vpid_tracker;
1407 case TRACKER_UID:
1408 return &session->uid_tracker;
1409 case TRACKER_VUID:
1410 return &session->vuid_tracker;
1411 case TRACKER_GID:
1412 return &session->gid_tracker;
1413 case TRACKER_VGID:
1414 return &session->vgid_tracker;
1415 default:
1416 WARN_ON_ONCE(1);
1417 return NULL;
1418 }
1419 }
1420
1421 int lttng_session_track_id(struct lttng_session *session,
1422 enum tracker_type tracker_type, int id)
1423 {
1424 struct lttng_id_tracker *tracker;
1425 int ret;
1426
1427 tracker = get_tracker(session, tracker_type);
1428 if (!tracker)
1429 return -EINVAL;
1430 if (id < -1)
1431 return -EINVAL;
1432 mutex_lock(&sessions_mutex);
1433 if (id == -1) {
1434 /* track all ids: destroy tracker. */
1435 lttng_id_tracker_destroy(tracker, true);
1436 ret = 0;
1437 } else {
1438 ret = lttng_id_tracker_add(tracker, id);
1439 }
1440 mutex_unlock(&sessions_mutex);
1441 return ret;
1442 }
1443
1444 int lttng_session_untrack_id(struct lttng_session *session,
1445 enum tracker_type tracker_type, int id)
1446 {
1447 struct lttng_id_tracker *tracker;
1448 int ret;
1449
1450 tracker = get_tracker(session, tracker_type);
1451 if (!tracker)
1452 return -EINVAL;
1453 if (id < -1)
1454 return -EINVAL;
1455 mutex_lock(&sessions_mutex);
1456 if (id == -1) {
1457 /* untrack all ids: replace by empty tracker. */
1458 ret = lttng_id_tracker_empty_set(tracker);
1459 } else {
1460 ret = lttng_id_tracker_del(tracker, id);
1461 }
1462 mutex_unlock(&sessions_mutex);
1463 return ret;
1464 }
1465
1466 static
1467 void *id_list_start(struct seq_file *m, loff_t *pos)
1468 {
1469 struct lttng_id_tracker *id_tracker = m->private;
1470 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1471 struct lttng_id_hash_node *e;
1472 int iter = 0, i;
1473
1474 mutex_lock(&sessions_mutex);
1475 if (id_tracker_p) {
1476 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1477 struct hlist_head *head = &id_tracker_p->id_hash[i];
1478
1479 lttng_hlist_for_each_entry(e, head, hlist) {
1480 if (iter++ >= *pos)
1481 return e;
1482 }
1483 }
1484 } else {
1485 /* ID tracker disabled. */
1486 if (iter >= *pos && iter == 0) {
1487 return id_tracker_p; /* empty tracker */
1488 }
1489 iter++;
1490 }
1491 /* End of list */
1492 return NULL;
1493 }
1494
1495 /* Called with sessions_mutex held. */
1496 static
1497 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1498 {
1499 struct lttng_id_tracker *id_tracker = m->private;
1500 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1501 struct lttng_id_hash_node *e;
1502 int iter = 0, i;
1503
1504 (*ppos)++;
1505 if (id_tracker_p) {
1506 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1507 struct hlist_head *head = &id_tracker_p->id_hash[i];
1508
1509 lttng_hlist_for_each_entry(e, head, hlist) {
1510 if (iter++ >= *ppos)
1511 return e;
1512 }
1513 }
1514 } else {
1515 /* ID tracker disabled. */
1516 if (iter >= *ppos && iter == 0)
1517 return p; /* empty tracker */
1518 iter++;
1519 }
1520
1521 /* End of list */
1522 return NULL;
1523 }
1524
1525 static
1526 void id_list_stop(struct seq_file *m, void *p)
1527 {
1528 mutex_unlock(&sessions_mutex);
1529 }
1530
1531 static
1532 int id_list_show(struct seq_file *m, void *p)
1533 {
1534 struct lttng_id_tracker *id_tracker = m->private;
1535 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1536 int id;
1537
1538 if (p == id_tracker_p) {
1539 /* Tracker disabled. */
1540 id = -1;
1541 } else {
1542 const struct lttng_id_hash_node *e = p;
1543
1544 id = lttng_id_tracker_get_node_id(e);
1545 }
1546 switch (id_tracker->tracker_type) {
1547 case TRACKER_PID:
1548 seq_printf(m, "process { pid = %d; };\n", id);
1549 break;
1550 case TRACKER_VPID:
1551 seq_printf(m, "process { vpid = %d; };\n", id);
1552 break;
1553 case TRACKER_UID:
1554 seq_printf(m, "user { uid = %d; };\n", id);
1555 break;
1556 case TRACKER_VUID:
1557 seq_printf(m, "user { vuid = %d; };\n", id);
1558 break;
1559 case TRACKER_GID:
1560 seq_printf(m, "group { gid = %d; };\n", id);
1561 break;
1562 case TRACKER_VGID:
1563 seq_printf(m, "group { vgid = %d; };\n", id);
1564 break;
1565 default:
1566 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1567 }
1568 return 0;
1569 }
1570
1571 static
1572 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1573 .start = id_list_start,
1574 .next = id_list_next,
1575 .stop = id_list_stop,
1576 .show = id_list_show,
1577 };
1578
1579 static
1580 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1581 {
1582 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1583 }
1584
1585 static
1586 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1587 {
1588 struct seq_file *m = file->private_data;
1589 struct lttng_id_tracker *id_tracker = m->private;
1590 int ret;
1591
1592 WARN_ON_ONCE(!id_tracker);
1593 ret = seq_release(inode, file);
1594 if (!ret)
1595 fput(id_tracker->session->file);
1596 return ret;
1597 }
1598
1599 const struct file_operations lttng_tracker_ids_list_fops = {
1600 .owner = THIS_MODULE,
1601 .open = lttng_tracker_ids_list_open,
1602 .read = seq_read,
1603 .llseek = seq_lseek,
1604 .release = lttng_tracker_ids_list_release,
1605 };
1606
1607 int lttng_session_list_tracker_ids(struct lttng_session *session,
1608 enum tracker_type tracker_type)
1609 {
1610 struct file *tracker_ids_list_file;
1611 struct seq_file *m;
1612 int file_fd, ret;
1613
1614 file_fd = lttng_get_unused_fd();
1615 if (file_fd < 0) {
1616 ret = file_fd;
1617 goto fd_error;
1618 }
1619
1620 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1621 &lttng_tracker_ids_list_fops,
1622 NULL, O_RDWR);
1623 if (IS_ERR(tracker_ids_list_file)) {
1624 ret = PTR_ERR(tracker_ids_list_file);
1625 goto file_error;
1626 }
1627 if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
1628 ret = -EOVERFLOW;
1629 goto refcount_error;
1630 }
1631 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1632 if (ret < 0)
1633 goto open_error;
1634 m = tracker_ids_list_file->private_data;
1635
1636 m->private = get_tracker(session, tracker_type);
1637 BUG_ON(!m->private);
1638 fd_install(file_fd, tracker_ids_list_file);
1639
1640 return file_fd;
1641
1642 open_error:
1643 atomic_long_dec(&session->file->f_count);
1644 refcount_error:
1645 fput(tracker_ids_list_file);
1646 file_error:
1647 put_unused_fd(file_fd);
1648 fd_error:
1649 return ret;
1650 }
1651
1652 /*
1653 * Enabler management.
1654 */
1655 static
1656 int lttng_match_enabler_star_glob(const char *desc_name,
1657 const char *pattern)
1658 {
1659 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1660 desc_name, LTTNG_SIZE_MAX))
1661 return 0;
1662 return 1;
1663 }
1664
1665 static
1666 int lttng_match_enabler_name(const char *desc_name,
1667 const char *name)
1668 {
1669 if (strcmp(desc_name, name))
1670 return 0;
1671 return 1;
1672 }
1673
1674 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
1675 struct lttng_enabler *enabler)
1676 {
1677 const char *desc_name, *enabler_name;
1678
1679 enabler_name = enabler->event_param.name;
1680 switch (enabler->event_param.instrumentation) {
1681 case LTTNG_KERNEL_TRACEPOINT:
1682 desc_name = desc->name;
1683 break;
1684 case LTTNG_KERNEL_SYSCALL:
1685 desc_name = desc->name;
1686 if (!strncmp(desc_name, "compat_", strlen("compat_")))
1687 desc_name += strlen("compat_");
1688 if (!strncmp(desc_name, "syscall_exit_",
1689 strlen("syscall_exit_"))) {
1690 desc_name += strlen("syscall_exit_");
1691 } else if (!strncmp(desc_name, "syscall_entry_",
1692 strlen("syscall_entry_"))) {
1693 desc_name += strlen("syscall_entry_");
1694 } else {
1695 WARN_ON_ONCE(1);
1696 return -EINVAL;
1697 }
1698 break;
1699 default:
1700 WARN_ON_ONCE(1);
1701 return -EINVAL;
1702 }
1703 switch (enabler->format_type) {
1704 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1705 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1706 case LTTNG_ENABLER_FORMAT_NAME:
1707 return lttng_match_enabler_name(desc_name, enabler_name);
1708 default:
1709 return -EINVAL;
1710 }
1711 }
1712
1713 static
1714 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
1715 struct lttng_event *event)
1716 {
1717 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
1718 event_enabler);
1719
1720 if (base_enabler->event_param.instrumentation != event->instrumentation)
1721 return 0;
1722 if (lttng_desc_match_enabler(event->desc, base_enabler)
1723 && event->chan == event_enabler->chan)
1724 return 1;
1725 else
1726 return 0;
1727 }
1728
1729 static
1730 int lttng_trigger_enabler_match_trigger(struct lttng_trigger_enabler *trigger_enabler,
1731 struct lttng_trigger *trigger)
1732 {
1733 struct lttng_enabler *base_enabler = lttng_trigger_enabler_as_enabler(
1734 trigger_enabler);
1735
1736 if (base_enabler->event_param.instrumentation != trigger->instrumentation)
1737 return 0;
1738 if (lttng_desc_match_enabler(trigger->desc, base_enabler)
1739 && trigger->group == trigger_enabler->group
1740 && trigger->id == trigger_enabler->id)
1741 return 1;
1742 else
1743 return 0;
1744 }
1745
1746 static
1747 struct lttng_enabler_ref *lttng_enabler_ref(
1748 struct list_head *enablers_ref_list,
1749 struct lttng_enabler *enabler)
1750 {
1751 struct lttng_enabler_ref *enabler_ref;
1752
1753 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
1754 if (enabler_ref->ref == enabler)
1755 return enabler_ref;
1756 }
1757 return NULL;
1758 }
1759
1760 static
1761 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
1762 {
1763 struct lttng_session *session = event_enabler->chan->session;
1764 struct lttng_probe_desc *probe_desc;
1765 const struct lttng_event_desc *desc;
1766 int i;
1767 struct list_head *probe_list;
1768
1769 probe_list = lttng_get_probe_list_head();
1770 /*
1771 * For each probe event, if we find that a probe event matches
1772 * our enabler, create an associated lttng_event if not
1773 * already present.
1774 */
1775 list_for_each_entry(probe_desc, probe_list, head) {
1776 for (i = 0; i < probe_desc->nr_events; i++) {
1777 int found = 0;
1778 struct hlist_head *head;
1779 struct lttng_event *event;
1780
1781 desc = probe_desc->event_desc[i];
1782 if (!lttng_desc_match_enabler(desc,
1783 lttng_event_enabler_as_enabler(event_enabler)))
1784 continue;
1785
1786 /*
1787 * Check if already created.
1788 */
1789 head = utils_borrow_hash_table_bucket(
1790 session->events_ht.table, LTTNG_EVENT_HT_SIZE,
1791 desc->name);
1792 lttng_hlist_for_each_entry(event, head, hlist) {
1793 if (event->desc == desc
1794 && event->chan == event_enabler->chan)
1795 found = 1;
1796 }
1797 if (found)
1798 continue;
1799
1800 /*
1801 * We need to create an event for this
1802 * event probe.
1803 */
1804 event = _lttng_event_create(event_enabler->chan,
1805 NULL, NULL, desc,
1806 LTTNG_KERNEL_TRACEPOINT);
1807 if (!event) {
1808 printk(KERN_INFO "Unable to create event %s\n",
1809 probe_desc->event_desc[i]->name);
1810 }
1811 }
1812 }
1813 }
1814
1815 static
1816 void lttng_create_tracepoint_trigger_if_missing(struct lttng_trigger_enabler *trigger_enabler)
1817 {
1818 struct lttng_trigger_group *trigger_group = trigger_enabler->group;
1819 struct lttng_probe_desc *probe_desc;
1820 const struct lttng_event_desc *desc;
1821 int i;
1822 struct list_head *probe_list;
1823
1824 probe_list = lttng_get_probe_list_head();
1825 /*
1826 * For each probe event, if we find that a probe event matches
1827 * our enabler, create an associated lttng_trigger if not
1828 * already present.
1829 */
1830 list_for_each_entry(probe_desc, probe_list, head) {
1831 for (i = 0; i < probe_desc->nr_events; i++) {
1832 int found = 0;
1833 struct hlist_head *head;
1834 struct lttng_trigger *trigger;
1835
1836 desc = probe_desc->event_desc[i];
1837 if (!lttng_desc_match_enabler(desc,
1838 lttng_trigger_enabler_as_enabler(trigger_enabler)))
1839 continue;
1840
1841 /*
1842 * Check if already created.
1843 */
1844 head = utils_borrow_hash_table_bucket(
1845 trigger_group->triggers_ht.table,
1846 LTTNG_TRIGGER_HT_SIZE, desc->name);
1847 lttng_hlist_for_each_entry(trigger, head, hlist) {
1848 if (trigger->desc == desc
1849 && trigger->id == trigger_enabler->id)
1850 found = 1;
1851 }
1852 if (found)
1853 continue;
1854
1855 /*
1856 * We need to create a trigger for this event probe.
1857 */
1858 trigger = _lttng_trigger_create(desc,
1859 trigger_enabler->id, trigger_group, NULL, NULL,
1860 LTTNG_KERNEL_TRACEPOINT);
1861 if (IS_ERR(trigger)) {
1862 printk(KERN_INFO "Unable to create trigger %s\n",
1863 probe_desc->event_desc[i]->name);
1864 }
1865 }
1866 }
1867 }
1868
1869 static
1870 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
1871 {
1872 int ret;
1873
1874 ret = lttng_syscalls_register_event(event_enabler->chan, NULL);
1875 WARN_ON_ONCE(ret);
1876 }
1877
1878 static
1879 void lttng_create_syscall_trigger_if_missing(struct lttng_trigger_enabler *trigger_enabler)
1880 {
1881 int ret;
1882
1883 ret = lttng_syscalls_register_trigger(trigger_enabler, NULL);
1884 WARN_ON_ONCE(ret);
1885 ret = lttng_syscals_create_matching_triggers(trigger_enabler, NULL);
1886 WARN_ON_ONCE(ret);
1887 }
1888
1889 /*
1890 * Create struct lttng_event if it is missing and present in the list of
1891 * tracepoint probes.
1892 * Should be called with sessions mutex held.
1893 */
1894 static
1895 void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
1896 {
1897 switch (event_enabler->base.event_param.instrumentation) {
1898 case LTTNG_KERNEL_TRACEPOINT:
1899 lttng_create_tracepoint_event_if_missing(event_enabler);
1900 break;
1901 case LTTNG_KERNEL_SYSCALL:
1902 lttng_create_syscall_event_if_missing(event_enabler);
1903 break;
1904 default:
1905 WARN_ON_ONCE(1);
1906 break;
1907 }
1908 }
1909
1910 /*
1911 * Create events associated with an event_enabler (if not already present),
1912 * and add backward reference from the event to the enabler.
1913 * Should be called with sessions mutex held.
1914 */
1915 static
1916 int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
1917 {
1918 struct lttng_session *session = event_enabler->chan->session;
1919 struct lttng_event *event;
1920
1921 /* First ensure that probe events are created for this enabler. */
1922 lttng_create_event_if_missing(event_enabler);
1923
1924 /* For each event matching event_enabler in session event list. */
1925 list_for_each_entry(event, &session->events, list) {
1926 struct lttng_enabler_ref *enabler_ref;
1927
1928 if (!lttng_event_enabler_match_event(event_enabler, event))
1929 continue;
1930 enabler_ref = lttng_enabler_ref(&event->enablers_ref_head,
1931 lttng_event_enabler_as_enabler(event_enabler));
1932 if (!enabler_ref) {
1933 /*
1934 * If no backward ref, create it.
1935 * Add backward ref from event to event_enabler.
1936 */
1937 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
1938 if (!enabler_ref)
1939 return -ENOMEM;
1940 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
1941 list_add(&enabler_ref->node,
1942 &event->enablers_ref_head);
1943 }
1944
1945 /*
1946 * Link filter bytecodes if not linked yet.
1947 */
1948 lttng_enabler_link_bytecode(event->desc,
1949 lttng_static_ctx,
1950 &event->bytecode_runtime_head,
1951 lttng_event_enabler_as_enabler(event_enabler));
1952
1953 /* TODO: merge event context. */
1954 }
1955 return 0;
1956 }
1957
1958 /*
1959 * Create struct lttng_trigger if it is missing and present in the list of
1960 * tracepoint probes.
1961 * Should be called with sessions mutex held.
1962 */
1963 static
1964 void lttng_create_trigger_if_missing(struct lttng_trigger_enabler *trigger_enabler)
1965 {
1966 switch (trigger_enabler->base.event_param.instrumentation) {
1967 case LTTNG_KERNEL_TRACEPOINT:
1968 lttng_create_tracepoint_trigger_if_missing(trigger_enabler);
1969 break;
1970 case LTTNG_KERNEL_SYSCALL:
1971 lttng_create_syscall_trigger_if_missing(trigger_enabler);
1972 break;
1973 default:
1974 WARN_ON_ONCE(1);
1975 break;
1976 }
1977 }
1978
1979 /*
1980 * Create triggers associated with a trigger enabler (if not already present).
1981 */
1982 static
1983 int lttng_trigger_enabler_ref_triggers(struct lttng_trigger_enabler *trigger_enabler)
1984 {
1985 struct lttng_trigger_group *trigger_group = trigger_enabler->group;
1986 struct lttng_trigger *trigger;
1987
1988 /* First ensure that probe triggers are created for this enabler. */
1989 lttng_create_trigger_if_missing(trigger_enabler);
1990
1991 /* Link the created trigger with its associated enabler. */
1992 list_for_each_entry(trigger, &trigger_group->triggers_head, list) {
1993 struct lttng_enabler_ref *enabler_ref;
1994
1995 if (!lttng_trigger_enabler_match_trigger(trigger_enabler, trigger))
1996 continue;
1997
1998 enabler_ref = lttng_enabler_ref(&trigger->enablers_ref_head,
1999 lttng_trigger_enabler_as_enabler(trigger_enabler));
2000 if (!enabler_ref) {
2001 /*
2002 * If no backward ref, create it.
2003 * Add backward ref from trigger to enabler.
2004 */
2005 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2006 if (!enabler_ref)
2007 return -ENOMEM;
2008
2009 enabler_ref->ref = lttng_trigger_enabler_as_enabler(
2010 trigger_enabler);
2011 list_add(&enabler_ref->node,
2012 &trigger->enablers_ref_head);
2013 }
2014
2015 /*
2016 * Link filter bytecodes if not linked yet.
2017 */
2018 lttng_enabler_link_bytecode(trigger->desc,
2019 trigger_group->ctx, &trigger->bytecode_runtime_head,
2020 lttng_trigger_enabler_as_enabler(trigger_enabler));
2021 }
2022 return 0;
2023 }
2024
2025 /*
2026 * Called at module load: connect the probe on all enablers matching
2027 * this event.
2028 * Called with sessions lock held.
2029 */
2030 int lttng_fix_pending_events(void)
2031 {
2032 struct lttng_session *session;
2033
2034 list_for_each_entry(session, &sessions, list)
2035 lttng_session_lazy_sync_event_enablers(session);
2036 return 0;
2037 }
2038
2039 static bool lttng_trigger_group_has_active_triggers(
2040 struct lttng_trigger_group *trigger_group)
2041 {
2042 struct lttng_trigger_enabler *trigger_enabler;
2043
2044 list_for_each_entry(trigger_enabler, &trigger_group->enablers_head,
2045 node) {
2046 if (trigger_enabler->base.enabled)
2047 return true;
2048 }
2049 return false;
2050 }
2051
2052 bool lttng_trigger_active(void)
2053 {
2054 struct lttng_trigger_group *trigger_group;
2055
2056 list_for_each_entry(trigger_group, &trigger_groups, node) {
2057 if (lttng_trigger_group_has_active_triggers(trigger_group))
2058 return true;
2059 }
2060 return false;
2061 }
2062
2063 int lttng_fix_pending_triggers(void)
2064 {
2065 struct lttng_trigger_group *trigger_group;
2066
2067 list_for_each_entry(trigger_group, &trigger_groups, node)
2068 lttng_trigger_group_sync_enablers(trigger_group);
2069 return 0;
2070 }
2071
2072 struct lttng_event_enabler *lttng_event_enabler_create(
2073 enum lttng_enabler_format_type format_type,
2074 struct lttng_kernel_event *event_param,
2075 struct lttng_channel *chan)
2076 {
2077 struct lttng_event_enabler *event_enabler;
2078
2079 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2080 if (!event_enabler)
2081 return NULL;
2082 event_enabler->base.format_type = format_type;
2083 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2084 memcpy(&event_enabler->base.event_param, event_param,
2085 sizeof(event_enabler->base.event_param));
2086 event_enabler->chan = chan;
2087 /* ctx left NULL */
2088 event_enabler->base.enabled = 0;
2089 event_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2090 mutex_lock(&sessions_mutex);
2091 list_add(&event_enabler->node, &event_enabler->chan->session->enablers_head);
2092 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2093 mutex_unlock(&sessions_mutex);
2094 return event_enabler;
2095 }
2096
2097 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2098 {
2099 mutex_lock(&sessions_mutex);
2100 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2101 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2102 mutex_unlock(&sessions_mutex);
2103 return 0;
2104 }
2105
2106 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2107 {
2108 mutex_lock(&sessions_mutex);
2109 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2110 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2111 mutex_unlock(&sessions_mutex);
2112 return 0;
2113 }
2114
2115 static
2116 int lttng_enabler_attach_bytecode(struct lttng_enabler *enabler,
2117 struct lttng_kernel_filter_bytecode __user *bytecode)
2118 {
2119 struct lttng_filter_bytecode_node *bytecode_node;
2120 uint32_t bytecode_len;
2121 int ret;
2122
2123 ret = get_user(bytecode_len, &bytecode->len);
2124 if (ret)
2125 return ret;
2126 bytecode_node = kzalloc(sizeof(*bytecode_node) + bytecode_len,
2127 GFP_KERNEL);
2128 if (!bytecode_node)
2129 return -ENOMEM;
2130 ret = copy_from_user(&bytecode_node->bc, bytecode,
2131 sizeof(*bytecode) + bytecode_len);
2132 if (ret)
2133 goto error_free;
2134
2135 bytecode_node->enabler = enabler;
2136 /* Enforce length based on allocated size */
2137 bytecode_node->bc.len = bytecode_len;
2138 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2139
2140 return 0;
2141
2142 error_free:
2143 kfree(bytecode_node);
2144 return ret;
2145 }
2146
2147 int lttng_event_enabler_attach_bytecode(struct lttng_event_enabler *event_enabler,
2148 struct lttng_kernel_filter_bytecode __user *bytecode)
2149 {
2150 int ret;
2151 ret = lttng_enabler_attach_bytecode(
2152 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2153 if (ret)
2154 goto error;
2155
2156 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2157 return 0;
2158
2159 error:
2160 return ret;
2161 }
2162
2163 int lttng_event_add_callsite(struct lttng_event *event,
2164 struct lttng_kernel_event_callsite __user *callsite)
2165 {
2166
2167 switch (event->instrumentation) {
2168 case LTTNG_KERNEL_UPROBE:
2169 return lttng_uprobes_event_add_callsite(event, callsite);
2170 default:
2171 return -EINVAL;
2172 }
2173 }
2174
2175 int lttng_event_enabler_attach_context(struct lttng_event_enabler *event_enabler,
2176 struct lttng_kernel_context *context_param)
2177 {
2178 return -ENOSYS;
2179 }
2180
2181 static
2182 void lttng_enabler_destroy(struct lttng_enabler *enabler)
2183 {
2184 struct lttng_filter_bytecode_node *filter_node, *tmp_filter_node;
2185
2186 /* Destroy filter bytecode */
2187 list_for_each_entry_safe(filter_node, tmp_filter_node,
2188 &enabler->filter_bytecode_head, node) {
2189 kfree(filter_node);
2190 }
2191 }
2192
2193 static
2194 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2195 {
2196 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2197
2198 /* Destroy contexts */
2199 lttng_destroy_context(event_enabler->ctx);
2200
2201 list_del(&event_enabler->node);
2202 kfree(event_enabler);
2203 }
2204
2205 struct lttng_trigger_enabler *lttng_trigger_enabler_create(
2206 struct lttng_trigger_group *trigger_group,
2207 enum lttng_enabler_format_type format_type,
2208 struct lttng_kernel_trigger *trigger_param)
2209 {
2210 struct lttng_trigger_enabler *trigger_enabler;
2211
2212 trigger_enabler = kzalloc(sizeof(*trigger_enabler), GFP_KERNEL);
2213 if (!trigger_enabler)
2214 return NULL;
2215
2216 trigger_enabler->base.format_type = format_type;
2217 INIT_LIST_HEAD(&trigger_enabler->base.filter_bytecode_head);
2218
2219 trigger_enabler->id = trigger_param->id;
2220
2221 memcpy(&trigger_enabler->base.event_param.name, trigger_param->name,
2222 sizeof(trigger_enabler->base.event_param.name));
2223 trigger_enabler->base.event_param.instrumentation = trigger_param->instrumentation;
2224 trigger_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2225
2226 trigger_enabler->base.enabled = 0;
2227 trigger_enabler->group = trigger_group;
2228
2229 mutex_lock(&sessions_mutex);
2230 list_add(&trigger_enabler->node, &trigger_enabler->group->enablers_head);
2231 lttng_trigger_group_sync_enablers(trigger_enabler->group);
2232
2233 mutex_unlock(&sessions_mutex);
2234
2235 return trigger_enabler;
2236 }
2237
2238 int lttng_trigger_enabler_enable(struct lttng_trigger_enabler *trigger_enabler)
2239 {
2240 mutex_lock(&sessions_mutex);
2241 lttng_trigger_enabler_as_enabler(trigger_enabler)->enabled = 1;
2242 lttng_trigger_group_sync_enablers(trigger_enabler->group);
2243 mutex_unlock(&sessions_mutex);
2244 return 0;
2245 }
2246
2247 int lttng_trigger_enabler_disable(struct lttng_trigger_enabler *trigger_enabler)
2248 {
2249 mutex_lock(&sessions_mutex);
2250 lttng_trigger_enabler_as_enabler(trigger_enabler)->enabled = 0;
2251 lttng_trigger_group_sync_enablers(trigger_enabler->group);
2252 mutex_unlock(&sessions_mutex);
2253 return 0;
2254 }
2255
2256 int lttng_trigger_enabler_attach_bytecode(struct lttng_trigger_enabler *trigger_enabler,
2257 struct lttng_kernel_filter_bytecode __user *bytecode)
2258 {
2259 int ret;
2260
2261 ret = lttng_enabler_attach_bytecode(
2262 lttng_trigger_enabler_as_enabler(trigger_enabler), bytecode);
2263 if (ret)
2264 goto error;
2265
2266 lttng_trigger_group_sync_enablers(trigger_enabler->group);
2267 return 0;
2268
2269 error:
2270 return ret;
2271 }
2272
2273 int lttng_trigger_add_callsite(struct lttng_trigger *trigger,
2274 struct lttng_kernel_event_callsite __user *callsite)
2275 {
2276
2277 switch (trigger->instrumentation) {
2278 case LTTNG_KERNEL_UPROBE:
2279 return lttng_uprobes_trigger_add_callsite(trigger, callsite);
2280 default:
2281 return -EINVAL;
2282 }
2283 }
2284
2285 int lttng_trigger_enabler_attach_context(struct lttng_trigger_enabler *trigger_enabler,
2286 struct lttng_kernel_context *context_param)
2287 {
2288 return -ENOSYS;
2289 }
2290
2291 static
2292 void lttng_trigger_enabler_destroy(struct lttng_trigger_enabler *trigger_enabler)
2293 {
2294 if (!trigger_enabler) {
2295 return;
2296 }
2297
2298 list_del(&trigger_enabler->node);
2299
2300 lttng_enabler_destroy(lttng_trigger_enabler_as_enabler(trigger_enabler));
2301 kfree(trigger_enabler);
2302 }
2303
2304 /*
2305 * lttng_session_sync_event_enablers should be called just before starting a
2306 * session.
2307 * Should be called with sessions mutex held.
2308 */
2309 static
2310 void lttng_session_sync_event_enablers(struct lttng_session *session)
2311 {
2312 struct lttng_event_enabler *event_enabler;
2313 struct lttng_event *event;
2314
2315 list_for_each_entry(event_enabler, &session->enablers_head, node)
2316 lttng_event_enabler_ref_events(event_enabler);
2317 /*
2318 * For each event, if at least one of its enablers is enabled,
2319 * and its channel and session transient states are enabled, we
2320 * enable the event, else we disable it.
2321 */
2322 list_for_each_entry(event, &session->events, list) {
2323 struct lttng_enabler_ref *enabler_ref;
2324 struct lttng_bytecode_runtime *runtime;
2325 int enabled = 0, has_enablers_without_bytecode = 0;
2326
2327 switch (event->instrumentation) {
2328 case LTTNG_KERNEL_TRACEPOINT:
2329 case LTTNG_KERNEL_SYSCALL:
2330 /* Enable events */
2331 list_for_each_entry(enabler_ref,
2332 &event->enablers_ref_head, node) {
2333 if (enabler_ref->ref->enabled) {
2334 enabled = 1;
2335 break;
2336 }
2337 }
2338 break;
2339 default:
2340 /* Not handled with lazy sync. */
2341 continue;
2342 }
2343 /*
2344 * Enabled state is based on union of enablers, with
2345 * intesection of session and channel transient enable
2346 * states.
2347 */
2348 enabled = enabled && session->tstate && event->chan->tstate;
2349
2350 WRITE_ONCE(event->enabled, enabled);
2351 /*
2352 * Sync tracepoint registration with event enabled
2353 * state.
2354 */
2355 if (enabled) {
2356 register_event(event);
2357 } else {
2358 _lttng_event_unregister(event);
2359 }
2360
2361 /* Check if has enablers without bytecode enabled */
2362 list_for_each_entry(enabler_ref,
2363 &event->enablers_ref_head, node) {
2364 if (enabler_ref->ref->enabled
2365 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2366 has_enablers_without_bytecode = 1;
2367 break;
2368 }
2369 }
2370 event->has_enablers_without_bytecode =
2371 has_enablers_without_bytecode;
2372
2373 /* Enable filters */
2374 list_for_each_entry(runtime,
2375 &event->bytecode_runtime_head, node)
2376 lttng_filter_sync_state(runtime);
2377 }
2378 }
2379
2380 /*
2381 * Apply enablers to session events, adding events to session if need
2382 * be. It is required after each modification applied to an active
2383 * session, and right before session "start".
2384 * "lazy" sync means we only sync if required.
2385 * Should be called with sessions mutex held.
2386 */
2387 static
2388 void lttng_session_lazy_sync_event_enablers(struct lttng_session *session)
2389 {
2390 /* We can skip if session is not active */
2391 if (!session->active)
2392 return;
2393 lttng_session_sync_event_enablers(session);
2394 }
2395
2396 static
2397 void lttng_trigger_group_sync_enablers(struct lttng_trigger_group *trigger_group)
2398 {
2399 struct lttng_trigger_enabler *trigger_enabler;
2400 struct lttng_trigger *trigger;
2401
2402 list_for_each_entry(trigger_enabler, &trigger_group->enablers_head, node)
2403 lttng_trigger_enabler_ref_triggers(trigger_enabler);
2404
2405 /*
2406 * For each trigger, if at least one of its enablers is enabled,
2407 * we enable the trigger, else we disable it.
2408 */
2409 list_for_each_entry(trigger, &trigger_group->triggers_head, list) {
2410 struct lttng_enabler_ref *enabler_ref;
2411 struct lttng_bytecode_runtime *runtime;
2412 int enabled = 0, has_enablers_without_bytecode = 0;
2413
2414 switch (trigger->instrumentation) {
2415 case LTTNG_KERNEL_TRACEPOINT:
2416 case LTTNG_KERNEL_SYSCALL:
2417 /* Enable triggers */
2418 list_for_each_entry(enabler_ref,
2419 &trigger->enablers_ref_head, node) {
2420 if (enabler_ref->ref->enabled) {
2421 enabled = 1;
2422 break;
2423 }
2424 }
2425 break;
2426 default:
2427 /* Not handled with sync. */
2428 continue;
2429 }
2430
2431 WRITE_ONCE(trigger->enabled, enabled);
2432 /*
2433 * Sync tracepoint registration with trigger enabled
2434 * state.
2435 */
2436 if (enabled) {
2437 if (!trigger->registered)
2438 register_trigger(trigger);
2439 } else {
2440 if (trigger->registered)
2441 _lttng_trigger_unregister(trigger);
2442 }
2443
2444 /* Check if has enablers without bytecode enabled */
2445 list_for_each_entry(enabler_ref,
2446 &trigger->enablers_ref_head, node) {
2447 if (enabler_ref->ref->enabled
2448 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2449 has_enablers_without_bytecode = 1;
2450 break;
2451 }
2452 }
2453 trigger->has_enablers_without_bytecode =
2454 has_enablers_without_bytecode;
2455
2456 /* Enable filters */
2457 list_for_each_entry(runtime,
2458 &trigger->bytecode_runtime_head, node)
2459 lttng_filter_sync_state(runtime);
2460 }
2461 }
2462
2463 /*
2464 * Serialize at most one packet worth of metadata into a metadata
2465 * channel.
2466 * We grab the metadata cache mutex to get exclusive access to our metadata
2467 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2468 * allows us to do racy operations such as looking for remaining space left in
2469 * packet and write, since mutual exclusion protects us from concurrent writes.
2470 * Mutual exclusion on the metadata cache allow us to read the cache content
2471 * without racing against reallocation of the cache by updates.
2472 * Returns the number of bytes written in the channel, 0 if no data
2473 * was written and a negative value on error.
2474 */
2475 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2476 struct channel *chan)
2477 {
2478 struct lib_ring_buffer_ctx ctx;
2479 int ret = 0;
2480 size_t len, reserve_len;
2481
2482 /*
2483 * Ensure we support mutiple get_next / put sequences followed by
2484 * put_next. The metadata cache lock protects reading the metadata
2485 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2486 * "flush" operations on the buffer invoked by different processes.
2487 * Moreover, since the metadata cache memory can be reallocated, we
2488 * need to have exclusive access against updates even though we only
2489 * read it.
2490 */
2491 mutex_lock(&stream->metadata_cache->lock);
2492 WARN_ON(stream->metadata_in < stream->metadata_out);
2493 if (stream->metadata_in != stream->metadata_out)
2494 goto end;
2495
2496 /* Metadata regenerated, change the version. */
2497 if (stream->metadata_cache->version != stream->version)
2498 stream->version = stream->metadata_cache->version;
2499
2500 len = stream->metadata_cache->metadata_written -
2501 stream->metadata_in;
2502 if (!len)
2503 goto end;
2504 reserve_len = min_t(size_t,
2505 stream->transport->ops.packet_avail_size(chan),
2506 len);
2507 lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
2508 sizeof(char), -1);
2509 /*
2510 * If reservation failed, return an error to the caller.
2511 */
2512 ret = stream->transport->ops.event_reserve(&ctx, 0);
2513 if (ret != 0) {
2514 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2515 goto end;
2516 }
2517 stream->transport->ops.event_write(&ctx,
2518 stream->metadata_cache->data + stream->metadata_in,
2519 reserve_len);
2520 stream->transport->ops.event_commit(&ctx);
2521 stream->metadata_in += reserve_len;
2522 ret = reserve_len;
2523
2524 end:
2525 mutex_unlock(&stream->metadata_cache->lock);
2526 return ret;
2527 }
2528
2529 /*
2530 * Write the metadata to the metadata cache.
2531 * Must be called with sessions_mutex held.
2532 * The metadata cache lock protects us from concurrent read access from
2533 * thread outputting metadata content to ring buffer.
2534 */
2535 int lttng_metadata_printf(struct lttng_session *session,
2536 const char *fmt, ...)
2537 {
2538 char *str;
2539 size_t len;
2540 va_list ap;
2541 struct lttng_metadata_stream *stream;
2542
2543 WARN_ON_ONCE(!READ_ONCE(session->active));
2544
2545 va_start(ap, fmt);
2546 str = kvasprintf(GFP_KERNEL, fmt, ap);
2547 va_end(ap);
2548 if (!str)
2549 return -ENOMEM;
2550
2551 len = strlen(str);
2552 mutex_lock(&session->metadata_cache->lock);
2553 if (session->metadata_cache->metadata_written + len >
2554 session->metadata_cache->cache_alloc) {
2555 char *tmp_cache_realloc;
2556 unsigned int tmp_cache_alloc_size;
2557
2558 tmp_cache_alloc_size = max_t(unsigned int,
2559 session->metadata_cache->cache_alloc + len,
2560 session->metadata_cache->cache_alloc << 1);
2561 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2562 if (!tmp_cache_realloc)
2563 goto err;
2564 if (session->metadata_cache->data) {
2565 memcpy(tmp_cache_realloc,
2566 session->metadata_cache->data,
2567 session->metadata_cache->cache_alloc);
2568 vfree(session->metadata_cache->data);
2569 }
2570
2571 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2572 session->metadata_cache->data = tmp_cache_realloc;
2573 }
2574 memcpy(session->metadata_cache->data +
2575 session->metadata_cache->metadata_written,
2576 str, len);
2577 session->metadata_cache->metadata_written += len;
2578 mutex_unlock(&session->metadata_cache->lock);
2579 kfree(str);
2580
2581 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
2582 wake_up_interruptible(&stream->read_wait);
2583
2584 return 0;
2585
2586 err:
2587 mutex_unlock(&session->metadata_cache->lock);
2588 kfree(str);
2589 return -ENOMEM;
2590 }
2591
2592 static
2593 int print_tabs(struct lttng_session *session, size_t nesting)
2594 {
2595 size_t i;
2596
2597 for (i = 0; i < nesting; i++) {
2598 int ret;
2599
2600 ret = lttng_metadata_printf(session, " ");
2601 if (ret) {
2602 return ret;
2603 }
2604 }
2605 return 0;
2606 }
2607
2608 /*
2609 * Must be called with sessions_mutex held.
2610 */
2611 static
2612 int _lttng_struct_type_statedump(struct lttng_session *session,
2613 const struct lttng_type *type,
2614 size_t nesting)
2615 {
2616 int ret;
2617 uint32_t i, nr_fields;
2618
2619 ret = print_tabs(session, nesting);
2620 if (ret)
2621 return ret;
2622 ret = lttng_metadata_printf(session,
2623 "struct {\n");
2624 if (ret)
2625 return ret;
2626 nr_fields = type->u._struct.nr_fields;
2627 for (i = 0; i < nr_fields; i++) {
2628 const struct lttng_event_field *iter_field;
2629
2630 iter_field = &type->u._struct.fields[i];
2631 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
2632 if (ret)
2633 return ret;
2634 }
2635 ret = print_tabs(session, nesting);
2636 if (ret)
2637 return ret;
2638 ret = lttng_metadata_printf(session,
2639 "}");
2640 return ret;
2641 }
2642
2643 /*
2644 * Must be called with sessions_mutex held.
2645 */
2646 static
2647 int _lttng_struct_statedump(struct lttng_session *session,
2648 const struct lttng_event_field *field,
2649 size_t nesting)
2650 {
2651 int ret;
2652
2653 ret = _lttng_struct_type_statedump(session,
2654 &field->type, nesting);
2655 if (ret)
2656 return ret;
2657 ret = lttng_metadata_printf(session,
2658 "_%s;\n",
2659 field->name);
2660 return ret;
2661 }
2662
2663 /*
2664 * Must be called with sessions_mutex held.
2665 */
2666 static
2667 int _lttng_variant_type_statedump(struct lttng_session *session,
2668 const struct lttng_type *type,
2669 size_t nesting)
2670 {
2671 int ret;
2672 uint32_t i, nr_choices;
2673
2674 ret = print_tabs(session, nesting);
2675 if (ret)
2676 return ret;
2677 ret = lttng_metadata_printf(session,
2678 "variant <_%s> {\n",
2679 type->u.variant.tag_name);
2680 if (ret)
2681 return ret;
2682 nr_choices = type->u.variant.nr_choices;
2683 for (i = 0; i < nr_choices; i++) {
2684 const struct lttng_event_field *iter_field;
2685
2686 iter_field = &type->u.variant.choices[i];
2687 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
2688 if (ret)
2689 return ret;
2690 }
2691 ret = print_tabs(session, nesting);
2692 if (ret)
2693 return ret;
2694 ret = lttng_metadata_printf(session,
2695 "}");
2696 return ret;
2697 }
2698
2699 /*
2700 * Must be called with sessions_mutex held.
2701 */
2702 static
2703 int _lttng_variant_statedump(struct lttng_session *session,
2704 const struct lttng_event_field *field,
2705 size_t nesting)
2706 {
2707 int ret;
2708
2709 ret = _lttng_variant_type_statedump(session,
2710 &field->type, nesting);
2711 if (ret)
2712 return ret;
2713 ret = lttng_metadata_printf(session,
2714 "_%s;\n",
2715 field->name);
2716 return ret;
2717 }
2718
2719 /*
2720 * Must be called with sessions_mutex held.
2721 */
2722 static
2723 int _lttng_array_compound_statedump(struct lttng_session *session,
2724 const struct lttng_event_field *field,
2725 size_t nesting)
2726 {
2727 int ret;
2728 const struct lttng_type *elem_type;
2729
2730 /* Only array of structures and variants are currently supported. */
2731 elem_type = field->type.u.array_compound.elem_type;
2732 switch (elem_type->atype) {
2733 case atype_struct:
2734 ret = _lttng_struct_type_statedump(session, elem_type, nesting);
2735 if (ret)
2736 return ret;
2737 break;
2738 case atype_variant:
2739 ret = _lttng_variant_type_statedump(session, elem_type, nesting);
2740 if (ret)
2741 return ret;
2742 break;
2743 default:
2744 return -EINVAL;
2745 }
2746 ret = lttng_metadata_printf(session,
2747 " _%s[%u];\n",
2748 field->name,
2749 field->type.u.array_compound.length);
2750 return ret;
2751 }
2752
2753 /*
2754 * Must be called with sessions_mutex held.
2755 */
2756 static
2757 int _lttng_sequence_compound_statedump(struct lttng_session *session,
2758 const struct lttng_event_field *field,
2759 size_t nesting)
2760 {
2761 int ret;
2762 const char *length_name;
2763 const struct lttng_type *elem_type;
2764
2765 length_name = field->type.u.sequence_compound.length_name;
2766
2767 /* Only array of structures and variants are currently supported. */
2768 elem_type = field->type.u.sequence_compound.elem_type;
2769 switch (elem_type->atype) {
2770 case atype_struct:
2771 ret = _lttng_struct_type_statedump(session, elem_type, nesting);
2772 if (ret)
2773 return ret;
2774 break;
2775 case atype_variant:
2776 ret = _lttng_variant_type_statedump(session, elem_type, nesting);
2777 if (ret)
2778 return ret;
2779 break;
2780 default:
2781 return -EINVAL;
2782 }
2783 ret = lttng_metadata_printf(session,
2784 " _%s[ _%s ];\n",
2785 field->name,
2786 length_name);
2787 return ret;
2788 }
2789
2790 /*
2791 * Must be called with sessions_mutex held.
2792 */
2793 static
2794 int _lttng_enum_statedump(struct lttng_session *session,
2795 const struct lttng_event_field *field,
2796 size_t nesting)
2797 {
2798 const struct lttng_enum_desc *enum_desc;
2799 const struct lttng_integer_type *container_type;
2800 int ret;
2801 unsigned int i, nr_entries;
2802
2803 enum_desc = field->type.u.basic.enumeration.desc;
2804 container_type = &field->type.u.basic.enumeration.container_type;
2805 nr_entries = enum_desc->nr_entries;
2806
2807 ret = print_tabs(session, nesting);
2808 if (ret)
2809 goto end;
2810 ret = lttng_metadata_printf(session,
2811 "enum : integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } {\n",
2812 container_type->size,
2813 container_type->alignment,
2814 container_type->signedness,
2815 (container_type->encoding == lttng_encode_none)
2816 ? "none"
2817 : (container_type->encoding == lttng_encode_UTF8)
2818 ? "UTF8"
2819 : "ASCII",
2820 container_type->base,
2821 #if __BYTE_ORDER == __BIG_ENDIAN
2822 container_type->reverse_byte_order ? " byte_order = le;" : ""
2823 #else
2824 container_type->reverse_byte_order ? " byte_order = be;" : ""
2825 #endif
2826 );
2827 if (ret)
2828 goto end;
2829 /* Dump all entries */
2830 for (i = 0; i < nr_entries; i++) {
2831 const struct lttng_enum_entry *entry = &enum_desc->entries[i];
2832 int j, len;
2833
2834 ret = print_tabs(session, nesting + 1);
2835 if (ret)
2836 goto end;
2837 ret = lttng_metadata_printf(session,
2838 "\"");
2839 if (ret)
2840 goto end;
2841 len = strlen(entry->string);
2842 /* Escape the character '"' */
2843 for (j = 0; j < len; j++) {
2844 char c = entry->string[j];
2845
2846 switch (c) {
2847 case '"':
2848 ret = lttng_metadata_printf(session,
2849 "\\\"");
2850 break;
2851 case '\\':
2852 ret = lttng_metadata_printf(session,
2853 "\\\\");
2854 break;
2855 default:
2856 ret = lttng_metadata_printf(session,
2857 "%c", c);
2858 break;
2859 }
2860 if (ret)
2861 goto end;
2862 }
2863 ret = lttng_metadata_printf(session, "\"");
2864 if (ret)
2865 goto end;
2866
2867 if (entry->options.is_auto) {
2868 ret = lttng_metadata_printf(session, ",\n");
2869 if (ret)
2870 goto end;
2871 } else {
2872 ret = lttng_metadata_printf(session,
2873 " = ");
2874 if (ret)
2875 goto end;
2876 if (entry->start.signedness)
2877 ret = lttng_metadata_printf(session,
2878 "%lld", (long long) entry->start.value);
2879 else
2880 ret = lttng_metadata_printf(session,
2881 "%llu", entry->start.value);
2882 if (ret)
2883 goto end;
2884 if (entry->start.signedness == entry->end.signedness &&
2885 entry->start.value
2886 == entry->end.value) {
2887 ret = lttng_metadata_printf(session,
2888 ",\n");
2889 } else {
2890 if (entry->end.signedness) {
2891 ret = lttng_metadata_printf(session,
2892 " ... %lld,\n",
2893 (long long) entry->end.value);
2894 } else {
2895 ret = lttng_metadata_printf(session,
2896 " ... %llu,\n",
2897 entry->end.value);
2898 }
2899 }
2900 if (ret)
2901 goto end;
2902 }
2903 }
2904 ret = print_tabs(session, nesting);
2905 if (ret)
2906 goto end;
2907 ret = lttng_metadata_printf(session, "} _%s;\n",
2908 field->name);
2909 end:
2910 return ret;
2911 }
2912
2913 /*
2914 * Must be called with sessions_mutex held.
2915 */
2916 static
2917 int _lttng_field_statedump(struct lttng_session *session,
2918 const struct lttng_event_field *field,
2919 size_t nesting)
2920 {
2921 int ret = 0;
2922
2923 switch (field->type.atype) {
2924 case atype_integer:
2925 ret = print_tabs(session, nesting);
2926 if (ret)
2927 return ret;
2928 ret = lttng_metadata_printf(session,
2929 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
2930 field->type.u.basic.integer.size,
2931 field->type.u.basic.integer.alignment,
2932 field->type.u.basic.integer.signedness,
2933 (field->type.u.basic.integer.encoding == lttng_encode_none)
2934 ? "none"
2935 : (field->type.u.basic.integer.encoding == lttng_encode_UTF8)
2936 ? "UTF8"
2937 : "ASCII",
2938 field->type.u.basic.integer.base,
2939 #if __BYTE_ORDER == __BIG_ENDIAN
2940 field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2941 #else
2942 field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2943 #endif
2944 field->name);
2945 break;
2946 case atype_enum:
2947 ret = _lttng_enum_statedump(session, field, nesting);
2948 break;
2949 case atype_array:
2950 case atype_array_bitfield:
2951 {
2952 const struct lttng_basic_type *elem_type;
2953
2954 elem_type = &field->type.u.array.elem_type;
2955 if (field->type.u.array.elem_alignment) {
2956 ret = print_tabs(session, nesting);
2957 if (ret)
2958 return ret;
2959 ret = lttng_metadata_printf(session,
2960 "struct { } align(%u) _%s_padding;\n",
2961 field->type.u.array.elem_alignment * CHAR_BIT,
2962 field->name);
2963 if (ret)
2964 return ret;
2965 }
2966 ret = print_tabs(session, nesting);
2967 if (ret)
2968 return ret;
2969 ret = lttng_metadata_printf(session,
2970 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
2971 elem_type->u.basic.integer.size,
2972 elem_type->u.basic.integer.alignment,
2973 elem_type->u.basic.integer.signedness,
2974 (elem_type->u.basic.integer.encoding == lttng_encode_none)
2975 ? "none"
2976 : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
2977 ? "UTF8"
2978 : "ASCII",
2979 elem_type->u.basic.integer.base,
2980 #if __BYTE_ORDER == __BIG_ENDIAN
2981 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2982 #else
2983 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2984 #endif
2985 field->name, field->type.u.array.length);
2986 break;
2987 }
2988 case atype_sequence:
2989 case atype_sequence_bitfield:
2990 {
2991 const struct lttng_basic_type *elem_type;
2992 const struct lttng_basic_type *length_type;
2993
2994 elem_type = &field->type.u.sequence.elem_type;
2995 length_type = &field->type.u.sequence.length_type;
2996 ret = print_tabs(session, nesting);
2997 if (ret)
2998 return ret;
2999 ret = lttng_metadata_printf(session,
3000 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
3001 length_type->u.basic.integer.size,
3002 (unsigned int) length_type->u.basic.integer.alignment,
3003 length_type->u.basic.integer.signedness,
3004 (length_type->u.basic.integer.encoding == lttng_encode_none)
3005 ? "none"
3006 : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8)
3007 ? "UTF8"
3008 : "ASCII"),
3009 length_type->u.basic.integer.base,
3010 #if __BYTE_ORDER == __BIG_ENDIAN
3011 length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
3012 #else
3013 length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
3014 #endif
3015 field->name);
3016 if (ret)
3017 return ret;
3018
3019 if (field->type.u.sequence.elem_alignment) {
3020 ret = print_tabs(session, nesting);
3021 if (ret)
3022 return ret;
3023 ret = lttng_metadata_printf(session,
3024 "struct { } align(%u) _%s_padding;\n",
3025 field->type.u.sequence.elem_alignment * CHAR_BIT,
3026 field->name);
3027 if (ret)
3028 return ret;
3029 }
3030 ret = print_tabs(session, nesting);
3031 if (ret)
3032 return ret;
3033 ret = lttng_metadata_printf(session,
3034 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
3035 elem_type->u.basic.integer.size,
3036 (unsigned int) elem_type->u.basic.integer.alignment,
3037 elem_type->u.basic.integer.signedness,
3038 (elem_type->u.basic.integer.encoding == lttng_encode_none)
3039 ? "none"
3040 : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
3041 ? "UTF8"
3042 : "ASCII"),
3043 elem_type->u.basic.integer.base,
3044 #if __BYTE_ORDER == __BIG_ENDIAN
3045 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
3046 #else
3047 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
3048 #endif
3049 field->name,
3050 field->name);
3051 break;
3052 }
3053
3054 case atype_string:
3055 /* Default encoding is UTF8 */
3056 ret = print_tabs(session, nesting);
3057 if (ret)
3058 return ret;
3059 ret = lttng_metadata_printf(session,
3060 "string%s _%s;\n",
3061 field->type.u.basic.string.encoding == lttng_encode_ASCII ?
3062 " { encoding = ASCII; }" : "",
3063 field->name);
3064 break;
3065 case atype_struct:
3066 ret = _lttng_struct_statedump(session, field, nesting);
3067 break;
3068 case atype_array_compound:
3069 ret = _lttng_array_compound_statedump(session, field, nesting);
3070 break;
3071 case atype_sequence_compound:
3072 ret = _lttng_sequence_compound_statedump(session, field, nesting);
3073 break;
3074 case atype_variant:
3075 ret = _lttng_variant_statedump(session, field, nesting);
3076 break;
3077
3078 default:
3079 WARN_ON_ONCE(1);
3080 return -EINVAL;
3081 }
3082 return ret;
3083 }
3084
3085 static
3086 int _lttng_context_metadata_statedump(struct lttng_session *session,
3087 struct lttng_ctx *ctx)
3088 {
3089 int ret = 0;
3090 int i;
3091
3092 if (!ctx)
3093 return 0;
3094 for (i = 0; i < ctx->nr_fields; i++) {
3095 const struct lttng_ctx_field *field = &ctx->fields[i];
3096
3097 ret = _lttng_field_statedump(session, &field->event_field, 2);
3098 if (ret)
3099 return ret;
3100 }
3101 return ret;
3102 }
3103
3104 static
3105 int _lttng_fields_metadata_statedump(struct lttng_session *session,
3106 struct lttng_event *event)
3107 {
3108 const struct lttng_event_desc *desc = event->desc;
3109 int ret = 0;
3110 int i;
3111
3112 for (i = 0; i < desc->nr_fields; i++) {
3113 const struct lttng_event_field *field = &desc->fields[i];
3114
3115 ret = _lttng_field_statedump(session, field, 2);
3116 if (ret)
3117 return ret;
3118 }
3119 return ret;
3120 }
3121
3122 /*
3123 * Must be called with sessions_mutex held.
3124 */
3125 static
3126 int _lttng_event_metadata_statedump(struct lttng_session *session,
3127 struct lttng_channel *chan,
3128 struct lttng_event *event)
3129 {
3130 int ret = 0;
3131
3132 if (event->metadata_dumped || !READ_ONCE(session->active))
3133 return 0;
3134 if (chan->channel_type == METADATA_CHANNEL)
3135 return 0;
3136
3137 ret = lttng_metadata_printf(session,
3138 "event {\n"
3139 " name = \"%s\";\n"
3140 " id = %u;\n"
3141 " stream_id = %u;\n",
3142 event->desc->name,
3143 event->id,
3144 event->chan->id);
3145 if (ret)
3146 goto end;
3147
3148 if (event->ctx) {
3149 ret = lttng_metadata_printf(session,
3150 " context := struct {\n");
3151 if (ret)
3152 goto end;
3153 }
3154 ret = _lttng_context_metadata_statedump(session, event->ctx);
3155 if (ret)
3156 goto end;
3157 if (event->ctx) {
3158 ret = lttng_metadata_printf(session,
3159 " };\n");
3160 if (ret)
3161 goto end;
3162 }
3163
3164 ret = lttng_metadata_printf(session,
3165 " fields := struct {\n"
3166 );
3167 if (ret)
3168 goto end;
3169
3170 ret = _lttng_fields_metadata_statedump(session, event);
3171 if (ret)
3172 goto end;
3173
3174 /*
3175 * LTTng space reservation can only reserve multiples of the
3176 * byte size.
3177 */
3178 ret = lttng_metadata_printf(session,
3179 " };\n"
3180 "};\n\n");
3181 if (ret)
3182 goto end;
3183
3184 event->metadata_dumped = 1;
3185 end:
3186 return ret;
3187
3188 }
3189
3190 /*
3191 * Must be called with sessions_mutex held.
3192 */
3193 static
3194 int _lttng_channel_metadata_statedump(struct lttng_session *session,
3195 struct lttng_channel *chan)
3196 {
3197 int ret = 0;
3198
3199 if (chan->metadata_dumped || !READ_ONCE(session->active))
3200 return 0;
3201
3202 if (chan->channel_type == METADATA_CHANNEL)
3203 return 0;
3204
3205 WARN_ON_ONCE(!chan->header_type);
3206 ret = lttng_metadata_printf(session,
3207 "stream {\n"
3208 " id = %u;\n"
3209 " event.header := %s;\n"
3210 " packet.context := struct packet_context;\n",
3211 chan->id,
3212 chan->header_type == 1 ? "struct event_header_compact" :
3213 "struct event_header_large");
3214 if (ret)
3215 goto end;
3216
3217 if (chan->ctx) {
3218 ret = lttng_metadata_printf(session,
3219 " event.context := struct {\n");
3220 if (ret)
3221 goto end;
3222 }
3223 ret = _lttng_context_metadata_statedump(session, chan->ctx);
3224 if (ret)
3225 goto end;
3226 if (chan->ctx) {
3227 ret = lttng_metadata_printf(session,
3228 " };\n");
3229 if (ret)
3230 goto end;
3231 }
3232
3233 ret = lttng_metadata_printf(session,
3234 "};\n\n");
3235
3236 chan->metadata_dumped = 1;
3237 end:
3238 return ret;
3239 }
3240
3241 /*
3242 * Must be called with sessions_mutex held.
3243 */
3244 static
3245 int _lttng_stream_packet_context_declare(struct lttng_session *session)
3246 {
3247 return lttng_metadata_printf(session,
3248 "struct packet_context {\n"
3249 " uint64_clock_monotonic_t timestamp_begin;\n"
3250 " uint64_clock_monotonic_t timestamp_end;\n"
3251 " uint64_t content_size;\n"
3252 " uint64_t packet_size;\n"
3253 " uint64_t packet_seq_num;\n"
3254 " unsigned long events_discarded;\n"
3255 " uint32_t cpu_id;\n"
3256 "};\n\n"
3257 );
3258 }
3259
3260 /*
3261 * Compact header:
3262 * id: range: 0 - 30.
3263 * id 31 is reserved to indicate an extended header.
3264 *
3265 * Large header:
3266 * id: range: 0 - 65534.
3267 * id 65535 is reserved to indicate an extended header.
3268 *
3269 * Must be called with sessions_mutex held.
3270 */
3271 static
3272 int _lttng_event_header_declare(struct lttng_session *session)
3273 {
3274 return lttng_metadata_printf(session,
3275 "struct event_header_compact {\n"
3276 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3277 " variant <id> {\n"
3278 " struct {\n"
3279 " uint27_clock_monotonic_t timestamp;\n"
3280 " } compact;\n"
3281 " struct {\n"
3282 " uint32_t id;\n"
3283 " uint64_clock_monotonic_t timestamp;\n"
3284 " } extended;\n"
3285 " } v;\n"
3286 "} align(%u);\n"
3287 "\n"
3288 "struct event_header_large {\n"
3289 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3290 " variant <id> {\n"
3291 " struct {\n"
3292 " uint32_clock_monotonic_t timestamp;\n"
3293 " } compact;\n"
3294 " struct {\n"
3295 " uint32_t id;\n"
3296 " uint64_clock_monotonic_t timestamp;\n"
3297 " } extended;\n"
3298 " } v;\n"
3299 "} align(%u);\n\n",
3300 lttng_alignof(uint32_t) * CHAR_BIT,
3301 lttng_alignof(uint16_t) * CHAR_BIT
3302 );
3303 }
3304
3305 /*
3306 * Approximation of NTP time of day to clock monotonic correlation,
3307 * taken at start of trace.
3308 * Yes, this is only an approximation. Yes, we can (and will) do better
3309 * in future versions.
3310 * This function may return a negative offset. It may happen if the
3311 * system sets the REALTIME clock to 0 after boot.
3312 */
3313 static
3314 int64_t measure_clock_offset(void)
3315 {
3316 uint64_t monotonic_avg, monotonic[2], realtime;
3317 uint64_t tcf = trace_clock_freq();
3318 int64_t offset;
3319 struct timespec rts = { 0, 0 };
3320 unsigned long flags;
3321
3322 /* Disable interrupts to increase correlation precision. */
3323 local_irq_save(flags);
3324 monotonic[0] = trace_clock_read64();
3325 getnstimeofday(&rts);
3326 monotonic[1] = trace_clock_read64();
3327 local_irq_restore(flags);
3328
3329 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3330 realtime = (uint64_t) rts.tv_sec * tcf;
3331 if (tcf == NSEC_PER_SEC) {
3332 realtime += rts.tv_nsec;
3333 } else {
3334 uint64_t n = rts.tv_nsec * tcf;
3335
3336 do_div(n, NSEC_PER_SEC);
3337 realtime += n;
3338 }
3339 offset = (int64_t) realtime - monotonic_avg;
3340 return offset;
3341 }
3342
3343 static
3344 int print_escaped_ctf_string(struct lttng_session *session, const char *string)
3345 {
3346 int ret;
3347 size_t i;
3348 char cur;
3349
3350 i = 0;
3351 cur = string[i];
3352 while (cur != '\0') {
3353 switch (cur) {
3354 case '\n':
3355 ret = lttng_metadata_printf(session, "%s", "\\n");
3356 break;
3357 case '\\':
3358 case '"':
3359 ret = lttng_metadata_printf(session, "%c", '\\');
3360 if (ret)
3361 goto error;
3362 /* We still print the current char */
3363 /* Fallthrough */
3364 default:
3365 ret = lttng_metadata_printf(session, "%c", cur);
3366 break;
3367 }
3368
3369 if (ret)
3370 goto error;
3371
3372 cur = string[++i];
3373 }
3374 error:
3375 return ret;
3376 }
3377
3378 static
3379 int print_metadata_escaped_field(struct lttng_session *session, const char *field,
3380 const char *field_value)
3381 {
3382 int ret;
3383
3384 ret = lttng_metadata_printf(session, " %s = \"", field);
3385 if (ret)
3386 goto error;
3387
3388 ret = print_escaped_ctf_string(session, field_value);
3389 if (ret)
3390 goto error;
3391
3392 ret = lttng_metadata_printf(session, "\";\n");
3393
3394 error:
3395 return ret;
3396 }
3397
3398 /*
3399 * Output metadata into this session's metadata buffers.
3400 * Must be called with sessions_mutex held.
3401 */
3402 static
3403 int _lttng_session_metadata_statedump(struct lttng_session *session)
3404 {
3405 unsigned char *uuid_c = session->uuid.b;
3406 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3407 const char *product_uuid;
3408 struct lttng_channel *chan;
3409 struct lttng_event *event;
3410 int ret = 0;
3411
3412 if (!READ_ONCE(session->active))
3413 return 0;
3414 if (session->metadata_dumped)
3415 goto skip_session;
3416
3417 snprintf(uuid_s, sizeof(uuid_s),
3418 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3419 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3420 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3421 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3422 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3423
3424 ret = lttng_metadata_printf(session,
3425 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3426 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3427 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3428 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3429 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3430 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3431 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3432 "\n"
3433 "trace {\n"
3434 " major = %u;\n"
3435 " minor = %u;\n"
3436 " uuid = \"%s\";\n"
3437 " byte_order = %s;\n"
3438 " packet.header := struct {\n"
3439 " uint32_t magic;\n"
3440 " uint8_t uuid[16];\n"
3441 " uint32_t stream_id;\n"
3442 " uint64_t stream_instance_id;\n"
3443 " };\n"
3444 "};\n\n",
3445 lttng_alignof(uint8_t) * CHAR_BIT,
3446 lttng_alignof(uint16_t) * CHAR_BIT,
3447 lttng_alignof(uint32_t) * CHAR_BIT,
3448 lttng_alignof(uint64_t) * CHAR_BIT,
3449 sizeof(unsigned long) * CHAR_BIT,
3450 lttng_alignof(unsigned long) * CHAR_BIT,
3451 CTF_SPEC_MAJOR,
3452 CTF_SPEC_MINOR,
3453 uuid_s,
3454 #if __BYTE_ORDER == __BIG_ENDIAN
3455 "be"
3456 #else
3457 "le"
3458 #endif
3459 );
3460 if (ret)
3461 goto end;
3462
3463 ret = lttng_metadata_printf(session,
3464 "env {\n"
3465 " hostname = \"%s\";\n"
3466 " domain = \"kernel\";\n"
3467 " sysname = \"%s\";\n"
3468 " kernel_release = \"%s\";\n"
3469 " kernel_version = \"%s\";\n"
3470 " tracer_name = \"lttng-modules\";\n"
3471 " tracer_major = %d;\n"
3472 " tracer_minor = %d;\n"
3473 " tracer_patchlevel = %d;\n"
3474 " trace_buffering_scheme = \"global\";\n",
3475 current->nsproxy->uts_ns->name.nodename,
3476 utsname()->sysname,
3477 utsname()->release,
3478 utsname()->version,
3479 LTTNG_MODULES_MAJOR_VERSION,
3480 LTTNG_MODULES_MINOR_VERSION,
3481 LTTNG_MODULES_PATCHLEVEL_VERSION
3482 );
3483 if (ret)
3484 goto end;
3485
3486 ret = print_metadata_escaped_field(session, "trace_name", session->name);
3487 if (ret)
3488 goto end;
3489 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3490 session->creation_time);
3491 if (ret)
3492 goto end;
3493
3494 /* Add the product UUID to the 'env' section */
3495 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3496 if (product_uuid) {
3497 ret = lttng_metadata_printf(session,
3498 " product_uuid = \"%s\";\n",
3499 product_uuid
3500 );
3501 if (ret)
3502 goto end;
3503 }
3504
3505 /* Close the 'env' section */
3506 ret = lttng_metadata_printf(session, "};\n\n");
3507 if (ret)
3508 goto end;
3509
3510 ret = lttng_metadata_printf(session,
3511 "clock {\n"
3512 " name = \"%s\";\n",
3513 trace_clock_name()
3514 );
3515 if (ret)
3516 goto end;
3517
3518 if (!trace_clock_uuid(clock_uuid_s)) {
3519 ret = lttng_metadata_printf(session,
3520 " uuid = \"%s\";\n",
3521 clock_uuid_s
3522 );
3523 if (ret)
3524 goto end;
3525 }
3526
3527 ret = lttng_metadata_printf(session,
3528 " description = \"%s\";\n"
3529 " freq = %llu; /* Frequency, in Hz */\n"
3530 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
3531 " offset = %lld;\n"
3532 "};\n\n",
3533 trace_clock_description(),
3534 (unsigned long long) trace_clock_freq(),
3535 (long long) measure_clock_offset()
3536 );
3537 if (ret)
3538 goto end;
3539
3540 ret = lttng_metadata_printf(session,
3541 "typealias integer {\n"
3542 " size = 27; align = 1; signed = false;\n"
3543 " map = clock.%s.value;\n"
3544 "} := uint27_clock_monotonic_t;\n"
3545 "\n"
3546 "typealias integer {\n"
3547 " size = 32; align = %u; signed = false;\n"
3548 " map = clock.%s.value;\n"
3549 "} := uint32_clock_monotonic_t;\n"
3550 "\n"
3551 "typealias integer {\n"
3552 " size = 64; align = %u; signed = false;\n"
3553 " map = clock.%s.value;\n"
3554 "} := uint64_clock_monotonic_t;\n\n",
3555 trace_clock_name(),
3556 lttng_alignof(uint32_t) * CHAR_BIT,
3557 trace_clock_name(),
3558 lttng_alignof(uint64_t) * CHAR_BIT,
3559 trace_clock_name()
3560 );
3561 if (ret)
3562 goto end;
3563
3564 ret = _lttng_stream_packet_context_declare(session);
3565 if (ret)
3566 goto end;
3567
3568 ret = _lttng_event_header_declare(session);
3569 if (ret)
3570 goto end;
3571
3572 skip_session:
3573 list_for_each_entry(chan, &session->chan, list) {
3574 ret = _lttng_channel_metadata_statedump(session, chan);
3575 if (ret)
3576 goto end;
3577 }
3578
3579 list_for_each_entry(event, &session->events, list) {
3580 ret = _lttng_event_metadata_statedump(session, event->chan, event);
3581 if (ret)
3582 goto end;
3583 }
3584 session->metadata_dumped = 1;
3585 end:
3586 return ret;
3587 }
3588
3589 /**
3590 * lttng_transport_register - LTT transport registration
3591 * @transport: transport structure
3592 *
3593 * Registers a transport which can be used as output to extract the data out of
3594 * LTTng. The module calling this registration function must ensure that no
3595 * trap-inducing code will be executed by the transport functions. E.g.
3596 * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
3597 * is made visible to the transport function. This registration acts as a
3598 * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
3599 * after its registration must it synchronize the TLBs.
3600 */
3601 void lttng_transport_register(struct lttng_transport *transport)
3602 {
3603 /*
3604 * Make sure no page fault can be triggered by the module about to be
3605 * registered. We deal with this here so we don't have to call
3606 * vmalloc_sync_all() in each module's init.
3607 */
3608 wrapper_vmalloc_sync_all();
3609
3610 mutex_lock(&sessions_mutex);
3611 list_add_tail(&transport->node, &lttng_transport_list);
3612 mutex_unlock(&sessions_mutex);
3613 }
3614 EXPORT_SYMBOL_GPL(lttng_transport_register);
3615
3616 /**
3617 * lttng_transport_unregister - LTT transport unregistration
3618 * @transport: transport structure
3619 */
3620 void lttng_transport_unregister(struct lttng_transport *transport)
3621 {
3622 mutex_lock(&sessions_mutex);
3623 list_del(&transport->node);
3624 mutex_unlock(&sessions_mutex);
3625 }
3626 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
3627
3628 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
3629
3630 enum cpuhp_state lttng_hp_prepare;
3631 enum cpuhp_state lttng_hp_online;
3632
3633 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
3634 {
3635 struct lttng_cpuhp_node *lttng_node;
3636
3637 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
3638 switch (lttng_node->component) {
3639 case LTTNG_RING_BUFFER_FRONTEND:
3640 return 0;
3641 case LTTNG_RING_BUFFER_BACKEND:
3642 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
3643 case LTTNG_RING_BUFFER_ITER:
3644 return 0;
3645 case LTTNG_CONTEXT_PERF_COUNTERS:
3646 return 0;
3647 default:
3648 return -EINVAL;
3649 }
3650 }
3651
3652 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
3653 {
3654 struct lttng_cpuhp_node *lttng_node;
3655
3656 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
3657 switch (lttng_node->component) {
3658 case LTTNG_RING_BUFFER_FRONTEND:
3659 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
3660 case LTTNG_RING_BUFFER_BACKEND:
3661 return 0;
3662 case LTTNG_RING_BUFFER_ITER:
3663 return 0;
3664 case LTTNG_CONTEXT_PERF_COUNTERS:
3665 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
3666 default:
3667 return -EINVAL;
3668 }
3669 }
3670
3671 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
3672 {
3673 struct lttng_cpuhp_node *lttng_node;
3674
3675 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
3676 switch (lttng_node->component) {
3677 case LTTNG_RING_BUFFER_FRONTEND:
3678 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
3679 case LTTNG_RING_BUFFER_BACKEND:
3680 return 0;
3681 case LTTNG_RING_BUFFER_ITER:
3682 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
3683 case LTTNG_CONTEXT_PERF_COUNTERS:
3684 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
3685 default:
3686 return -EINVAL;
3687 }
3688 }
3689
3690 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
3691 {
3692 struct lttng_cpuhp_node *lttng_node;
3693
3694 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
3695 switch (lttng_node->component) {
3696 case LTTNG_RING_BUFFER_FRONTEND:
3697 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
3698 case LTTNG_RING_BUFFER_BACKEND:
3699 return 0;
3700 case LTTNG_RING_BUFFER_ITER:
3701 return 0;
3702 case LTTNG_CONTEXT_PERF_COUNTERS:
3703 return 0;
3704 default:
3705 return -EINVAL;
3706 }
3707 }
3708
3709 static int __init lttng_init_cpu_hotplug(void)
3710 {
3711 int ret;
3712
3713 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
3714 lttng_hotplug_prepare,
3715 lttng_hotplug_dead);
3716 if (ret < 0) {
3717 return ret;
3718 }
3719 lttng_hp_prepare = ret;
3720 lttng_rb_set_hp_prepare(ret);
3721
3722 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
3723 lttng_hotplug_online,
3724 lttng_hotplug_offline);
3725 if (ret < 0) {
3726 cpuhp_remove_multi_state(lttng_hp_prepare);
3727 lttng_hp_prepare = 0;
3728 return ret;
3729 }
3730 lttng_hp_online = ret;
3731 lttng_rb_set_hp_online(ret);
3732
3733 return 0;
3734 }
3735
3736 static void __exit lttng_exit_cpu_hotplug(void)
3737 {
3738 lttng_rb_set_hp_online(0);
3739 cpuhp_remove_multi_state(lttng_hp_online);
3740 lttng_rb_set_hp_prepare(0);
3741 cpuhp_remove_multi_state(lttng_hp_prepare);
3742 }
3743
3744 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
3745 static int lttng_init_cpu_hotplug(void)
3746 {
3747 return 0;
3748 }
3749 static void lttng_exit_cpu_hotplug(void)
3750 {
3751 }
3752 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
3753
3754
3755 static int __init lttng_events_init(void)
3756 {
3757 int ret;
3758
3759 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
3760 if (ret)
3761 return ret;
3762 ret = wrapper_get_pfnblock_flags_mask_init();
3763 if (ret)
3764 return ret;
3765 ret = wrapper_get_pageblock_flags_mask_init();
3766 if (ret)
3767 return ret;
3768 ret = lttng_probes_init();
3769 if (ret)
3770 return ret;
3771 ret = lttng_context_init();
3772 if (ret)
3773 return ret;
3774 ret = lttng_tracepoint_init();
3775 if (ret)
3776 goto error_tp;
3777 event_cache = KMEM_CACHE(lttng_event, 0);
3778 if (!event_cache) {
3779 ret = -ENOMEM;
3780 goto error_kmem_event;
3781 }
3782 trigger_cache = KMEM_CACHE(lttng_trigger, 0);
3783 if (!trigger_cache) {
3784 ret = -ENOMEM;
3785 goto error_kmem_trigger;
3786 }
3787 ret = lttng_abi_init();
3788 if (ret)
3789 goto error_abi;
3790 ret = lttng_logger_init();
3791 if (ret)
3792 goto error_logger;
3793 ret = lttng_init_cpu_hotplug();
3794 if (ret)
3795 goto error_hotplug;
3796 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
3797 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3798 __stringify(LTTNG_MODULES_MINOR_VERSION),
3799 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3800 LTTNG_MODULES_EXTRAVERSION,
3801 LTTNG_VERSION_NAME,
3802 #ifdef LTTNG_EXTRA_VERSION_GIT
3803 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3804 #else
3805 "",
3806 #endif
3807 #ifdef LTTNG_EXTRA_VERSION_NAME
3808 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3809 #else
3810 "");
3811 #endif
3812 return 0;
3813
3814 error_hotplug:
3815 lttng_logger_exit();
3816 error_logger:
3817 lttng_abi_exit();
3818 error_abi:
3819 kmem_cache_destroy(trigger_cache);
3820 error_kmem_trigger:
3821 kmem_cache_destroy(event_cache);
3822 error_kmem_event:
3823 lttng_tracepoint_exit();
3824 error_tp:
3825 lttng_context_exit();
3826 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
3827 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3828 __stringify(LTTNG_MODULES_MINOR_VERSION),
3829 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3830 LTTNG_MODULES_EXTRAVERSION,
3831 LTTNG_VERSION_NAME,
3832 #ifdef LTTNG_EXTRA_VERSION_GIT
3833 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3834 #else
3835 "",
3836 #endif
3837 #ifdef LTTNG_EXTRA_VERSION_NAME
3838 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3839 #else
3840 "");
3841 #endif
3842 return ret;
3843 }
3844
3845 module_init(lttng_events_init);
3846
3847 static void __exit lttng_events_exit(void)
3848 {
3849 struct lttng_session *session, *tmpsession;
3850
3851 lttng_exit_cpu_hotplug();
3852 lttng_logger_exit();
3853 lttng_abi_exit();
3854 list_for_each_entry_safe(session, tmpsession, &sessions, list)
3855 lttng_session_destroy(session);
3856 kmem_cache_destroy(event_cache);
3857 kmem_cache_destroy(trigger_cache);
3858 lttng_tracepoint_exit();
3859 lttng_context_exit();
3860 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
3861 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3862 __stringify(LTTNG_MODULES_MINOR_VERSION),
3863 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3864 LTTNG_MODULES_EXTRAVERSION,
3865 LTTNG_VERSION_NAME,
3866 #ifdef LTTNG_EXTRA_VERSION_GIT
3867 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3868 #else
3869 "",
3870 #endif
3871 #ifdef LTTNG_EXTRA_VERSION_NAME
3872 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3873 #else
3874 "");
3875 #endif
3876 }
3877
3878 module_exit(lttng_events_exit);
3879
3880 #include "extra_version/patches.i"
3881 #ifdef LTTNG_EXTRA_VERSION_GIT
3882 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
3883 #endif
3884 #ifdef LTTNG_EXTRA_VERSION_NAME
3885 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
3886 #endif
3887 MODULE_LICENSE("GPL and additional rights");
3888 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
3889 MODULE_DESCRIPTION("LTTng tracer");
3890 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
3891 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
3892 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
3893 LTTNG_MODULES_EXTRAVERSION);
LTTng modules - Deliverables
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