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Implement event notifiers for uprobes
[lttng-modules.git] / src / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
2 *
3 * lttng-events.c
4 *
5 * Holds LTTng per-session event registry.
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10 /*
11 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
12 * overrides a function with a define.
13 */
14 #include "wrapper/page_alloc.h"
15
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/jiffies.h>
21 #include <linux/utsname.h>
22 #include <linux/err.h>
23 #include <linux/seq_file.h>
24 #include <linux/file.h>
25 #include <linux/anon_inodes.h>
26 #include <wrapper/file.h>
27 #include <linux/uaccess.h>
28 #include <linux/vmalloc.h>
29 #include <linux/dmi.h>
30
31 #include <wrapper/uuid.h>
32 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
33 #include <wrapper/random.h>
34 #include <wrapper/tracepoint.h>
35 #include <wrapper/list.h>
36 #include <wrapper/types.h>
37 #include <lttng/kernel-version.h>
38 #include <lttng/events.h>
39 #include <lttng/tracer.h>
40 #include <lttng/event-notifier-notification.h>
41 #include <lttng/abi-old.h>
42 #include <lttng/endian.h>
43 #include <lttng/string-utils.h>
44 #include <lttng/utils.h>
45 #include <ringbuffer/backend.h>
46 #include <ringbuffer/frontend.h>
47 #include <wrapper/time.h>
48
49 #define METADATA_CACHE_DEFAULT_SIZE 4096
50
51 static LIST_HEAD(sessions);
52 static LIST_HEAD(event_notifier_groups);
53 static LIST_HEAD(lttng_transport_list);
54 /*
55 * Protect the sessions and metadata caches.
56 */
57 static DEFINE_MUTEX(sessions_mutex);
58 static struct kmem_cache *event_cache;
59 static struct kmem_cache *event_notifier_cache;
60
61 static void lttng_session_lazy_sync_event_enablers(struct lttng_session *session);
62 static void lttng_session_sync_event_enablers(struct lttng_session *session);
63 static void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler);
64 static void lttng_event_notifier_enabler_destroy(struct lttng_event_notifier_enabler *event_notifier_enabler);
65 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
66
67 static void _lttng_event_destroy(struct lttng_event *event);
68 static void _lttng_event_notifier_destroy(struct lttng_event_notifier *event_notifier);
69 static void _lttng_channel_destroy(struct lttng_channel *chan);
70 static int _lttng_event_unregister(struct lttng_event *event);
71 static int _lttng_event_notifier_unregister(struct lttng_event_notifier *event_notifier);
72 static
73 int _lttng_event_metadata_statedump(struct lttng_session *session,
74 struct lttng_channel *chan,
75 struct lttng_event *event);
76 static
77 int _lttng_session_metadata_statedump(struct lttng_session *session);
78 static
79 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
80 static
81 int _lttng_type_statedump(struct lttng_session *session,
82 const struct lttng_type *type,
83 size_t nesting);
84 static
85 int _lttng_field_statedump(struct lttng_session *session,
86 const struct lttng_event_field *field,
87 size_t nesting);
88
89 void synchronize_trace(void)
90 {
91 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,1,0))
92 synchronize_rcu();
93 #else
94 synchronize_sched();
95 #endif
96
97 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
98 #ifdef CONFIG_PREEMPT_RT_FULL
99 synchronize_rcu();
100 #endif
101 #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
102 #ifdef CONFIG_PREEMPT_RT
103 synchronize_rcu();
104 #endif
105 #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
106 }
107
108 void lttng_lock_sessions(void)
109 {
110 mutex_lock(&sessions_mutex);
111 }
112
113 void lttng_unlock_sessions(void)
114 {
115 mutex_unlock(&sessions_mutex);
116 }
117
118 static struct lttng_transport *lttng_transport_find(const char *name)
119 {
120 struct lttng_transport *transport;
121
122 list_for_each_entry(transport, &lttng_transport_list, node) {
123 if (!strcmp(transport->name, name))
124 return transport;
125 }
126 return NULL;
127 }
128
129 /*
130 * Called with sessions lock held.
131 */
132 int lttng_session_active(void)
133 {
134 struct lttng_session *iter;
135
136 list_for_each_entry(iter, &sessions, list) {
137 if (iter->active)
138 return 1;
139 }
140 return 0;
141 }
142
143 struct lttng_session *lttng_session_create(void)
144 {
145 struct lttng_session *session;
146 struct lttng_metadata_cache *metadata_cache;
147 int i;
148
149 mutex_lock(&sessions_mutex);
150 session = lttng_kvzalloc(sizeof(struct lttng_session), GFP_KERNEL);
151 if (!session)
152 goto err;
153 INIT_LIST_HEAD(&session->chan);
154 INIT_LIST_HEAD(&session->events);
155 lttng_guid_gen(&session->uuid);
156
157 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
158 GFP_KERNEL);
159 if (!metadata_cache)
160 goto err_free_session;
161 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
162 if (!metadata_cache->data)
163 goto err_free_cache;
164 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
165 kref_init(&metadata_cache->refcount);
166 mutex_init(&metadata_cache->lock);
167 session->metadata_cache = metadata_cache;
168 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
169 memcpy(&metadata_cache->uuid, &session->uuid,
170 sizeof(metadata_cache->uuid));
171 INIT_LIST_HEAD(&session->enablers_head);
172 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
173 INIT_HLIST_HEAD(&session->events_ht.table[i]);
174 list_add(&session->list, &sessions);
175 session->pid_tracker.session = session;
176 session->pid_tracker.tracker_type = TRACKER_PID;
177 session->vpid_tracker.session = session;
178 session->vpid_tracker.tracker_type = TRACKER_VPID;
179 session->uid_tracker.session = session;
180 session->uid_tracker.tracker_type = TRACKER_UID;
181 session->vuid_tracker.session = session;
182 session->vuid_tracker.tracker_type = TRACKER_VUID;
183 session->gid_tracker.session = session;
184 session->gid_tracker.tracker_type = TRACKER_GID;
185 session->vgid_tracker.session = session;
186 session->vgid_tracker.tracker_type = TRACKER_VGID;
187 mutex_unlock(&sessions_mutex);
188 return session;
189
190 err_free_cache:
191 kfree(metadata_cache);
192 err_free_session:
193 lttng_kvfree(session);
194 err:
195 mutex_unlock(&sessions_mutex);
196 return NULL;
197 }
198
199 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
200 {
201 struct lttng_transport *transport = NULL;
202 struct lttng_event_notifier_group *event_notifier_group;
203 const char *transport_name = "relay-event-notifier";
204 size_t subbuf_size = 4096; //TODO
205 size_t num_subbuf = 16; //TODO
206 unsigned int switch_timer_interval = 0;
207 unsigned int read_timer_interval = 0;
208 int i;
209
210 mutex_lock(&sessions_mutex);
211
212 transport = lttng_transport_find(transport_name);
213 if (!transport) {
214 printk(KERN_WARNING "LTTng: transport %s not found\n",
215 transport_name);
216 goto notransport;
217 }
218 if (!try_module_get(transport->owner)) {
219 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
220 transport_name);
221 goto notransport;
222 }
223
224 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
225 GFP_KERNEL);
226 if (!event_notifier_group)
227 goto nomem;
228
229 /*
230 * Initialize the ring buffer used to store event notifier
231 * notifications.
232 */
233 event_notifier_group->ops = &transport->ops;
234 event_notifier_group->chan = transport->ops.channel_create(
235 transport_name, event_notifier_group, NULL,
236 subbuf_size, num_subbuf, switch_timer_interval,
237 read_timer_interval);
238 if (!event_notifier_group->chan)
239 goto create_error;
240
241 event_notifier_group->transport = transport;
242
243 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
244 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
245 for (i = 0; i < LTTNG_EVENT_NOTIFIER_HT_SIZE; i++)
246 INIT_HLIST_HEAD(&event_notifier_group->event_notifiers_ht.table[i]);
247
248 list_add(&event_notifier_group->node, &event_notifier_groups);
249
250 mutex_unlock(&sessions_mutex);
251
252 return event_notifier_group;
253
254 create_error:
255 lttng_kvfree(event_notifier_group);
256 nomem:
257 if (transport)
258 module_put(transport->owner);
259 notransport:
260 mutex_unlock(&sessions_mutex);
261 return NULL;
262 }
263
264 void metadata_cache_destroy(struct kref *kref)
265 {
266 struct lttng_metadata_cache *cache =
267 container_of(kref, struct lttng_metadata_cache, refcount);
268 vfree(cache->data);
269 kfree(cache);
270 }
271
272 void lttng_session_destroy(struct lttng_session *session)
273 {
274 struct lttng_channel *chan, *tmpchan;
275 struct lttng_event *event, *tmpevent;
276 struct lttng_metadata_stream *metadata_stream;
277 struct lttng_event_enabler *event_enabler, *tmp_event_enabler;
278 int ret;
279
280 mutex_lock(&sessions_mutex);
281 WRITE_ONCE(session->active, 0);
282 list_for_each_entry(chan, &session->chan, list) {
283 ret = lttng_syscalls_unregister(chan);
284 WARN_ON(ret);
285 }
286 list_for_each_entry(event, &session->events, list) {
287 ret = _lttng_event_unregister(event);
288 WARN_ON(ret);
289 }
290 synchronize_trace(); /* Wait for in-flight events to complete */
291 list_for_each_entry(chan, &session->chan, list) {
292 ret = lttng_syscalls_destroy(chan);
293 WARN_ON(ret);
294 }
295 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
296 &session->enablers_head, node)
297 lttng_event_enabler_destroy(event_enabler);
298 list_for_each_entry_safe(event, tmpevent, &session->events, list)
299 _lttng_event_destroy(event);
300 list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
301 BUG_ON(chan->channel_type == METADATA_CHANNEL);
302 _lttng_channel_destroy(chan);
303 }
304 mutex_lock(&session->metadata_cache->lock);
305 list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
306 _lttng_metadata_channel_hangup(metadata_stream);
307 mutex_unlock(&session->metadata_cache->lock);
308 lttng_id_tracker_destroy(&session->pid_tracker, false);
309 lttng_id_tracker_destroy(&session->vpid_tracker, false);
310 lttng_id_tracker_destroy(&session->uid_tracker, false);
311 lttng_id_tracker_destroy(&session->vuid_tracker, false);
312 lttng_id_tracker_destroy(&session->gid_tracker, false);
313 lttng_id_tracker_destroy(&session->vgid_tracker, false);
314 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
315 list_del(&session->list);
316 mutex_unlock(&sessions_mutex);
317 lttng_kvfree(session);
318 }
319
320 void lttng_event_notifier_group_destroy(
321 struct lttng_event_notifier_group *event_notifier_group)
322 {
323 struct lttng_event_notifier_enabler *event_notifier_enabler, *tmp_event_notifier_enabler;
324 struct lttng_event_notifier *event_notifier, *tmpevent_notifier;
325 int ret;
326
327 if (!event_notifier_group)
328 return;
329
330 mutex_lock(&sessions_mutex);
331
332 list_for_each_entry_safe(event_notifier, tmpevent_notifier,
333 &event_notifier_group->event_notifiers_head, list) {
334 ret = _lttng_event_notifier_unregister(event_notifier);
335 WARN_ON(ret);
336 }
337
338 /* Wait for in-flight event notifier to complete */
339 synchronize_trace();
340
341 irq_work_sync(&event_notifier_group->wakeup_pending);
342
343 list_for_each_entry_safe(event_notifier_enabler, tmp_event_notifier_enabler,
344 &event_notifier_group->enablers_head, node)
345 lttng_event_notifier_enabler_destroy(event_notifier_enabler);
346
347 list_for_each_entry_safe(event_notifier, tmpevent_notifier,
348 &event_notifier_group->event_notifiers_head, list)
349 _lttng_event_notifier_destroy(event_notifier);
350
351 event_notifier_group->ops->channel_destroy(event_notifier_group->chan);
352 module_put(event_notifier_group->transport->owner);
353 list_del(&event_notifier_group->node);
354
355 mutex_unlock(&sessions_mutex);
356 lttng_kvfree(event_notifier_group);
357 }
358
359 int lttng_session_statedump(struct lttng_session *session)
360 {
361 int ret;
362
363 mutex_lock(&sessions_mutex);
364 ret = lttng_statedump_start(session);
365 mutex_unlock(&sessions_mutex);
366 return ret;
367 }
368
369 int lttng_session_enable(struct lttng_session *session)
370 {
371 int ret = 0;
372 struct lttng_channel *chan;
373
374 mutex_lock(&sessions_mutex);
375 if (session->active) {
376 ret = -EBUSY;
377 goto end;
378 }
379
380 /* Set transient enabler state to "enabled" */
381 session->tstate = 1;
382
383 /* We need to sync enablers with session before activation. */
384 lttng_session_sync_event_enablers(session);
385
386 /*
387 * Snapshot the number of events per channel to know the type of header
388 * we need to use.
389 */
390 list_for_each_entry(chan, &session->chan, list) {
391 if (chan->header_type)
392 continue; /* don't change it if session stop/restart */
393 if (chan->free_event_id < 31)
394 chan->header_type = 1; /* compact */
395 else
396 chan->header_type = 2; /* large */
397 }
398
399 /* Clear each stream's quiescent state. */
400 list_for_each_entry(chan, &session->chan, list) {
401 if (chan->channel_type != METADATA_CHANNEL)
402 lib_ring_buffer_clear_quiescent_channel(chan->chan);
403 }
404
405 WRITE_ONCE(session->active, 1);
406 WRITE_ONCE(session->been_active, 1);
407 ret = _lttng_session_metadata_statedump(session);
408 if (ret) {
409 WRITE_ONCE(session->active, 0);
410 goto end;
411 }
412 ret = lttng_statedump_start(session);
413 if (ret)
414 WRITE_ONCE(session->active, 0);
415 end:
416 mutex_unlock(&sessions_mutex);
417 return ret;
418 }
419
420 int lttng_session_disable(struct lttng_session *session)
421 {
422 int ret = 0;
423 struct lttng_channel *chan;
424
425 mutex_lock(&sessions_mutex);
426 if (!session->active) {
427 ret = -EBUSY;
428 goto end;
429 }
430 WRITE_ONCE(session->active, 0);
431
432 /* Set transient enabler state to "disabled" */
433 session->tstate = 0;
434 lttng_session_sync_event_enablers(session);
435
436 /* Set each stream's quiescent state. */
437 list_for_each_entry(chan, &session->chan, list) {
438 if (chan->channel_type != METADATA_CHANNEL)
439 lib_ring_buffer_set_quiescent_channel(chan->chan);
440 }
441 end:
442 mutex_unlock(&sessions_mutex);
443 return ret;
444 }
445
446 int lttng_session_metadata_regenerate(struct lttng_session *session)
447 {
448 int ret = 0;
449 struct lttng_channel *chan;
450 struct lttng_event *event;
451 struct lttng_metadata_cache *cache = session->metadata_cache;
452 struct lttng_metadata_stream *stream;
453
454 mutex_lock(&sessions_mutex);
455 if (!session->active) {
456 ret = -EBUSY;
457 goto end;
458 }
459
460 mutex_lock(&cache->lock);
461 memset(cache->data, 0, cache->cache_alloc);
462 cache->metadata_written = 0;
463 cache->version++;
464 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list) {
465 stream->metadata_out = 0;
466 stream->metadata_in = 0;
467 }
468 mutex_unlock(&cache->lock);
469
470 session->metadata_dumped = 0;
471 list_for_each_entry(chan, &session->chan, list) {
472 chan->metadata_dumped = 0;
473 }
474
475 list_for_each_entry(event, &session->events, list) {
476 event->metadata_dumped = 0;
477 }
478
479 ret = _lttng_session_metadata_statedump(session);
480
481 end:
482 mutex_unlock(&sessions_mutex);
483 return ret;
484 }
485
486 int lttng_channel_enable(struct lttng_channel *channel)
487 {
488 int ret = 0;
489
490 mutex_lock(&sessions_mutex);
491 if (channel->channel_type == METADATA_CHANNEL) {
492 ret = -EPERM;
493 goto end;
494 }
495 if (channel->enabled) {
496 ret = -EEXIST;
497 goto end;
498 }
499 /* Set transient enabler state to "enabled" */
500 channel->tstate = 1;
501 lttng_session_sync_event_enablers(channel->session);
502 /* Set atomically the state to "enabled" */
503 WRITE_ONCE(channel->enabled, 1);
504 end:
505 mutex_unlock(&sessions_mutex);
506 return ret;
507 }
508
509 int lttng_channel_disable(struct lttng_channel *channel)
510 {
511 int ret = 0;
512
513 mutex_lock(&sessions_mutex);
514 if (channel->channel_type == METADATA_CHANNEL) {
515 ret = -EPERM;
516 goto end;
517 }
518 if (!channel->enabled) {
519 ret = -EEXIST;
520 goto end;
521 }
522 /* Set atomically the state to "disabled" */
523 WRITE_ONCE(channel->enabled, 0);
524 /* Set transient enabler state to "enabled" */
525 channel->tstate = 0;
526 lttng_session_sync_event_enablers(channel->session);
527 end:
528 mutex_unlock(&sessions_mutex);
529 return ret;
530 }
531
532 int lttng_event_enable(struct lttng_event *event)
533 {
534 int ret = 0;
535
536 mutex_lock(&sessions_mutex);
537 if (event->chan->channel_type == METADATA_CHANNEL) {
538 ret = -EPERM;
539 goto end;
540 }
541 if (event->enabled) {
542 ret = -EEXIST;
543 goto end;
544 }
545 switch (event->instrumentation) {
546 case LTTNG_KERNEL_TRACEPOINT:
547 case LTTNG_KERNEL_SYSCALL:
548 ret = -EINVAL;
549 break;
550 case LTTNG_KERNEL_KPROBE:
551 case LTTNG_KERNEL_UPROBE:
552 case LTTNG_KERNEL_NOOP:
553 WRITE_ONCE(event->enabled, 1);
554 break;
555 case LTTNG_KERNEL_KRETPROBE:
556 ret = lttng_kretprobes_event_enable_state(event, 1);
557 break;
558 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
559 default:
560 WARN_ON_ONCE(1);
561 ret = -EINVAL;
562 }
563 end:
564 mutex_unlock(&sessions_mutex);
565 return ret;
566 }
567
568 int lttng_event_disable(struct lttng_event *event)
569 {
570 int ret = 0;
571
572 mutex_lock(&sessions_mutex);
573 if (event->chan->channel_type == METADATA_CHANNEL) {
574 ret = -EPERM;
575 goto end;
576 }
577 if (!event->enabled) {
578 ret = -EEXIST;
579 goto end;
580 }
581 switch (event->instrumentation) {
582 case LTTNG_KERNEL_TRACEPOINT:
583 case LTTNG_KERNEL_SYSCALL:
584 ret = -EINVAL;
585 break;
586 case LTTNG_KERNEL_KPROBE:
587 case LTTNG_KERNEL_UPROBE:
588 case LTTNG_KERNEL_NOOP:
589 WRITE_ONCE(event->enabled, 0);
590 break;
591 case LTTNG_KERNEL_KRETPROBE:
592 ret = lttng_kretprobes_event_enable_state(event, 0);
593 break;
594 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
595 default:
596 WARN_ON_ONCE(1);
597 ret = -EINVAL;
598 }
599 end:
600 mutex_unlock(&sessions_mutex);
601 return ret;
602 }
603
604 int lttng_event_notifier_enable(struct lttng_event_notifier *event_notifier)
605 {
606 int ret = 0;
607
608 mutex_lock(&sessions_mutex);
609 if (event_notifier->enabled) {
610 ret = -EEXIST;
611 goto end;
612 }
613 switch (event_notifier->instrumentation) {
614 case LTTNG_KERNEL_TRACEPOINT:
615 ret = -EINVAL;
616 break;
617 case LTTNG_KERNEL_KPROBE:
618 case LTTNG_KERNEL_UPROBE:
619 WRITE_ONCE(event_notifier->enabled, 1);
620 break;
621 case LTTNG_KERNEL_SYSCALL:
622 case LTTNG_KERNEL_FUNCTION:
623 case LTTNG_KERNEL_NOOP:
624 case LTTNG_KERNEL_KRETPROBE:
625 default:
626 WARN_ON_ONCE(1);
627 ret = -EINVAL;
628 }
629 end:
630 mutex_unlock(&sessions_mutex);
631 return ret;
632 }
633
634 int lttng_event_notifier_disable(struct lttng_event_notifier *event_notifier)
635 {
636 int ret = 0;
637
638 mutex_lock(&sessions_mutex);
639 if (!event_notifier->enabled) {
640 ret = -EEXIST;
641 goto end;
642 }
643 switch (event_notifier->instrumentation) {
644 case LTTNG_KERNEL_TRACEPOINT:
645 ret = -EINVAL;
646 break;
647 case LTTNG_KERNEL_KPROBE:
648 case LTTNG_KERNEL_UPROBE:
649 WRITE_ONCE(event_notifier->enabled, 0);
650 break;
651 case LTTNG_KERNEL_SYSCALL:
652 case LTTNG_KERNEL_FUNCTION:
653 case LTTNG_KERNEL_NOOP:
654 case LTTNG_KERNEL_KRETPROBE:
655 default:
656 WARN_ON_ONCE(1);
657 ret = -EINVAL;
658 }
659 end:
660 mutex_unlock(&sessions_mutex);
661 return ret;
662 }
663
664 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
665 const char *transport_name,
666 void *buf_addr,
667 size_t subbuf_size, size_t num_subbuf,
668 unsigned int switch_timer_interval,
669 unsigned int read_timer_interval,
670 enum channel_type channel_type)
671 {
672 struct lttng_channel *chan;
673 struct lttng_transport *transport = NULL;
674
675 mutex_lock(&sessions_mutex);
676 if (session->been_active && channel_type != METADATA_CHANNEL)
677 goto active; /* Refuse to add channel to active session */
678 transport = lttng_transport_find(transport_name);
679 if (!transport) {
680 printk(KERN_WARNING "LTTng: transport %s not found\n",
681 transport_name);
682 goto notransport;
683 }
684 if (!try_module_get(transport->owner)) {
685 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
686 goto notransport;
687 }
688 chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL);
689 if (!chan)
690 goto nomem;
691 chan->session = session;
692 chan->id = session->free_chan_id++;
693 chan->ops = &transport->ops;
694 /*
695 * Note: the channel creation op already writes into the packet
696 * headers. Therefore the "chan" information used as input
697 * should be already accessible.
698 */
699 chan->chan = transport->ops.channel_create(transport_name,
700 chan, buf_addr, subbuf_size, num_subbuf,
701 switch_timer_interval, read_timer_interval);
702 if (!chan->chan)
703 goto create_error;
704 chan->tstate = 1;
705 chan->enabled = 1;
706 chan->transport = transport;
707 chan->channel_type = channel_type;
708 list_add(&chan->list, &session->chan);
709 mutex_unlock(&sessions_mutex);
710 return chan;
711
712 create_error:
713 kfree(chan);
714 nomem:
715 if (transport)
716 module_put(transport->owner);
717 notransport:
718 active:
719 mutex_unlock(&sessions_mutex);
720 return NULL;
721 }
722
723 /*
724 * Only used internally at session destruction for per-cpu channels, and
725 * when metadata channel is released.
726 * Needs to be called with sessions mutex held.
727 */
728 static
729 void _lttng_channel_destroy(struct lttng_channel *chan)
730 {
731 chan->ops->channel_destroy(chan->chan);
732 module_put(chan->transport->owner);
733 list_del(&chan->list);
734 lttng_destroy_context(chan->ctx);
735 kfree(chan);
736 }
737
738 void lttng_metadata_channel_destroy(struct lttng_channel *chan)
739 {
740 BUG_ON(chan->channel_type != METADATA_CHANNEL);
741
742 /* Protect the metadata cache with the sessions_mutex. */
743 mutex_lock(&sessions_mutex);
744 _lttng_channel_destroy(chan);
745 mutex_unlock(&sessions_mutex);
746 }
747 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
748
749 static
750 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
751 {
752 stream->finalized = 1;
753 wake_up_interruptible(&stream->read_wait);
754 }
755
756 /*
757 * Supports event creation while tracing session is active.
758 * Needs to be called with sessions mutex held.
759 */
760 struct lttng_event *_lttng_event_create(struct lttng_channel *chan,
761 struct lttng_kernel_event *event_param,
762 void *filter,
763 const struct lttng_event_desc *event_desc,
764 enum lttng_kernel_instrumentation itype)
765 {
766 struct lttng_session *session = chan->session;
767 struct lttng_event *event;
768 const char *event_name;
769 struct hlist_head *head;
770 int ret;
771
772 if (chan->free_event_id == -1U) {
773 ret = -EMFILE;
774 goto full;
775 }
776
777 switch (itype) {
778 case LTTNG_KERNEL_TRACEPOINT:
779 event_name = event_desc->name;
780 break;
781 case LTTNG_KERNEL_KPROBE:
782 case LTTNG_KERNEL_UPROBE:
783 case LTTNG_KERNEL_KRETPROBE:
784 case LTTNG_KERNEL_NOOP:
785 case LTTNG_KERNEL_SYSCALL:
786 event_name = event_param->name;
787 break;
788 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
789 default:
790 WARN_ON_ONCE(1);
791 ret = -EINVAL;
792 goto type_error;
793 }
794
795 head = utils_borrow_hash_table_bucket(session->events_ht.table,
796 LTTNG_EVENT_HT_SIZE, event_name);
797 lttng_hlist_for_each_entry(event, head, hlist) {
798 WARN_ON_ONCE(!event->desc);
799 if (!strncmp(event->desc->name, event_name,
800 LTTNG_KERNEL_SYM_NAME_LEN - 1)
801 && chan == event->chan) {
802 ret = -EEXIST;
803 goto exist;
804 }
805 }
806
807 event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
808 if (!event) {
809 ret = -ENOMEM;
810 goto cache_error;
811 }
812 event->chan = chan;
813 event->filter = filter;
814 event->id = chan->free_event_id++;
815 event->instrumentation = itype;
816 event->evtype = LTTNG_TYPE_EVENT;
817 INIT_LIST_HEAD(&event->bytecode_runtime_head);
818 INIT_LIST_HEAD(&event->enablers_ref_head);
819
820 switch (itype) {
821 case LTTNG_KERNEL_TRACEPOINT:
822 /* Event will be enabled by enabler sync. */
823 event->enabled = 0;
824 event->registered = 0;
825 event->desc = lttng_event_desc_get(event_name);
826 if (!event->desc) {
827 ret = -ENOENT;
828 goto register_error;
829 }
830 /* Populate lttng_event structure before event registration. */
831 smp_wmb();
832 break;
833 case LTTNG_KERNEL_KPROBE:
834 /*
835 * Needs to be explicitly enabled after creation, since
836 * we may want to apply filters.
837 */
838 event->enabled = 0;
839 event->registered = 1;
840 /*
841 * Populate lttng_event structure before event
842 * registration.
843 */
844 smp_wmb();
845 ret = lttng_kprobes_register_event(event_name,
846 event_param->u.kprobe.symbol_name,
847 event_param->u.kprobe.offset,
848 event_param->u.kprobe.addr,
849 event);
850 if (ret) {
851 ret = -EINVAL;
852 goto register_error;
853 }
854 ret = try_module_get(event->desc->owner);
855 WARN_ON_ONCE(!ret);
856 break;
857 case LTTNG_KERNEL_KRETPROBE:
858 {
859 struct lttng_event *event_return;
860
861 /* kretprobe defines 2 events */
862 /*
863 * Needs to be explicitly enabled after creation, since
864 * we may want to apply filters.
865 */
866 event->enabled = 0;
867 event->registered = 1;
868 event_return =
869 kmem_cache_zalloc(event_cache, GFP_KERNEL);
870 if (!event_return) {
871 ret = -ENOMEM;
872 goto register_error;
873 }
874 event_return->chan = chan;
875 event_return->filter = filter;
876 event_return->id = chan->free_event_id++;
877 event_return->enabled = 0;
878 event_return->registered = 1;
879 event_return->instrumentation = itype;
880 /*
881 * Populate lttng_event structure before kretprobe registration.
882 */
883 smp_wmb();
884 ret = lttng_kretprobes_register(event_name,
885 event_param->u.kretprobe.symbol_name,
886 event_param->u.kretprobe.offset,
887 event_param->u.kretprobe.addr,
888 event, event_return);
889 if (ret) {
890 kmem_cache_free(event_cache, event_return);
891 ret = -EINVAL;
892 goto register_error;
893 }
894 /* Take 2 refs on the module: one per event. */
895 ret = try_module_get(event->desc->owner);
896 WARN_ON_ONCE(!ret);
897 ret = try_module_get(event->desc->owner);
898 WARN_ON_ONCE(!ret);
899 ret = _lttng_event_metadata_statedump(chan->session, chan,
900 event_return);
901 WARN_ON_ONCE(ret > 0);
902 if (ret) {
903 kmem_cache_free(event_cache, event_return);
904 module_put(event->desc->owner);
905 module_put(event->desc->owner);
906 goto statedump_error;
907 }
908 list_add(&event_return->list, &chan->session->events);
909 break;
910 }
911 case LTTNG_KERNEL_NOOP:
912 case LTTNG_KERNEL_SYSCALL:
913 /*
914 * Needs to be explicitly enabled after creation, since
915 * we may want to apply filters.
916 */
917 event->enabled = 0;
918 event->registered = 0;
919 event->desc = event_desc;
920 switch (event_param->u.syscall.entryexit) {
921 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
922 ret = -EINVAL;
923 goto register_error;
924 case LTTNG_KERNEL_SYSCALL_ENTRY:
925 event->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
926 break;
927 case LTTNG_KERNEL_SYSCALL_EXIT:
928 event->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
929 break;
930 }
931 switch (event_param->u.syscall.abi) {
932 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
933 ret = -EINVAL;
934 goto register_error;
935 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
936 event->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
937 break;
938 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
939 event->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
940 break;
941 }
942 if (!event->desc) {
943 ret = -EINVAL;
944 goto register_error;
945 }
946 break;
947 case LTTNG_KERNEL_UPROBE:
948 /*
949 * Needs to be explicitly enabled after creation, since
950 * we may want to apply filters.
951 */
952 event->enabled = 0;
953 event->registered = 1;
954
955 /*
956 * Populate lttng_event structure before event
957 * registration.
958 */
959 smp_wmb();
960
961 ret = lttng_uprobes_register_event(event_param->name,
962 event_param->u.uprobe.fd,
963 event);
964 if (ret)
965 goto register_error;
966 ret = try_module_get(event->desc->owner);
967 WARN_ON_ONCE(!ret);
968 break;
969 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
970 default:
971 WARN_ON_ONCE(1);
972 ret = -EINVAL;
973 goto register_error;
974 }
975 ret = _lttng_event_metadata_statedump(chan->session, chan, event);
976 WARN_ON_ONCE(ret > 0);
977 if (ret) {
978 goto statedump_error;
979 }
980 hlist_add_head(&event->hlist, head);
981 list_add(&event->list, &chan->session->events);
982 return event;
983
984 statedump_error:
985 /* If a statedump error occurs, events will not be readable. */
986 register_error:
987 kmem_cache_free(event_cache, event);
988 cache_error:
989 exist:
990 type_error:
991 full:
992 return ERR_PTR(ret);
993 }
994
995 struct lttng_event_notifier *_lttng_event_notifier_create(
996 const struct lttng_event_desc *event_desc,
997 uint64_t token, struct lttng_event_notifier_group *event_notifier_group,
998 struct lttng_kernel_event_notifier *event_notifier_param,
999 void *filter, enum lttng_kernel_instrumentation itype)
1000 {
1001 struct lttng_event_notifier *event_notifier;
1002 const char *event_name;
1003 struct hlist_head *head;
1004 int ret;
1005
1006 switch (itype) {
1007 case LTTNG_KERNEL_TRACEPOINT:
1008 event_name = event_desc->name;
1009 break;
1010 case LTTNG_KERNEL_KPROBE:
1011 case LTTNG_KERNEL_UPROBE:
1012 event_name = event_notifier_param->event.name;
1013 break;
1014 case LTTNG_KERNEL_KRETPROBE:
1015 case LTTNG_KERNEL_FUNCTION:
1016 case LTTNG_KERNEL_NOOP:
1017 case LTTNG_KERNEL_SYSCALL:
1018 default:
1019 WARN_ON_ONCE(1);
1020 ret = -EINVAL;
1021 goto type_error;
1022 }
1023
1024 head = utils_borrow_hash_table_bucket(event_notifier_group->event_notifiers_ht.table,
1025 LTTNG_EVENT_NOTIFIER_HT_SIZE, event_name);
1026 lttng_hlist_for_each_entry(event_notifier, head, hlist) {
1027 WARN_ON_ONCE(!event_notifier->desc);
1028 if (!strncmp(event_notifier->desc->name, event_name,
1029 LTTNG_KERNEL_SYM_NAME_LEN - 1)
1030 && event_notifier_group == event_notifier->group
1031 && token == event_notifier->user_token) {
1032 ret = -EEXIST;
1033 goto exist;
1034 }
1035 }
1036
1037 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
1038 if (!event_notifier) {
1039 ret = -ENOMEM;
1040 goto cache_error;
1041 }
1042
1043 event_notifier->group = event_notifier_group;
1044 event_notifier->user_token = token;
1045 event_notifier->filter = filter;
1046 event_notifier->instrumentation = itype;
1047 event_notifier->evtype = LTTNG_TYPE_EVENT;
1048 event_notifier->send_notification = lttng_event_notifier_notification_send;
1049 INIT_LIST_HEAD(&event_notifier->bytecode_runtime_head);
1050 INIT_LIST_HEAD(&event_notifier->enablers_ref_head);
1051
1052 switch (itype) {
1053 case LTTNG_KERNEL_TRACEPOINT:
1054 /* Event will be enabled by enabler sync. */
1055 event_notifier->enabled = 0;
1056 event_notifier->registered = 0;
1057 event_notifier->desc = lttng_event_desc_get(event_name);
1058 if (!event_notifier->desc) {
1059 ret = -ENOENT;
1060 goto register_error;
1061 }
1062 /* Populate lttng_event_notifier structure before event registration. */
1063 smp_wmb();
1064 break;
1065 case LTTNG_KERNEL_KPROBE:
1066 /*
1067 * Needs to be explicitly enabled after creation, since
1068 * we may want to apply filters.
1069 */
1070 event_notifier->enabled = 0;
1071 event_notifier->registered = 1;
1072 /*
1073 * Populate lttng_event_notifier structure before event
1074 * registration.
1075 */
1076 smp_wmb();
1077 ret = lttng_kprobes_register_event_notifier(
1078 event_notifier_param->event.u.kprobe.symbol_name,
1079 event_notifier_param->event.u.kprobe.offset,
1080 event_notifier_param->event.u.kprobe.addr,
1081 event_notifier);
1082 if (ret) {
1083 ret = -EINVAL;
1084 goto register_error;
1085 }
1086 ret = try_module_get(event_notifier->desc->owner);
1087 WARN_ON_ONCE(!ret);
1088 break;
1089 case LTTNG_KERNEL_UPROBE:
1090 /*
1091 * Needs to be explicitly enabled after creation, since
1092 * we may want to apply filters.
1093 */
1094 event_notifier->enabled = 0;
1095 event_notifier->registered = 1;
1096
1097 /*
1098 * Populate lttng_event_notifier structure before
1099 * event_notifier registration.
1100 */
1101 smp_wmb();
1102
1103 ret = lttng_uprobes_register_event_notifier(
1104 event_notifier_param->event.name,
1105 event_notifier_param->event.u.uprobe.fd,
1106 event_notifier);
1107 if (ret)
1108 goto register_error;
1109 ret = try_module_get(event_notifier->desc->owner);
1110 WARN_ON_ONCE(!ret);
1111 break;
1112 case LTTNG_KERNEL_KRETPROBE:
1113 case LTTNG_KERNEL_FUNCTION:
1114 case LTTNG_KERNEL_NOOP:
1115 case LTTNG_KERNEL_SYSCALL:
1116 default:
1117 WARN_ON_ONCE(1);
1118 ret = -EINVAL;
1119 goto register_error;
1120 }
1121
1122 list_add(&event_notifier->list, &event_notifier_group->event_notifiers_head);
1123 hlist_add_head(&event_notifier->hlist, head);
1124 return event_notifier;
1125
1126 register_error:
1127 kmem_cache_free(event_notifier_cache, event_notifier);
1128 cache_error:
1129 exist:
1130 type_error:
1131 return ERR_PTR(ret);
1132 }
1133
1134 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
1135 struct lttng_kernel_event *event_param,
1136 void *filter,
1137 const struct lttng_event_desc *event_desc,
1138 enum lttng_kernel_instrumentation itype)
1139 {
1140 struct lttng_event *event;
1141
1142 mutex_lock(&sessions_mutex);
1143 event = _lttng_event_create(chan, event_param, filter, event_desc,
1144 itype);
1145 mutex_unlock(&sessions_mutex);
1146 return event;
1147 }
1148
1149 struct lttng_event_notifier *lttng_event_notifier_create(
1150 const struct lttng_event_desc *event_desc,
1151 uint64_t id, struct lttng_event_notifier_group *event_notifier_group,
1152 struct lttng_kernel_event_notifier *event_notifier_param,
1153 void *filter, enum lttng_kernel_instrumentation itype)
1154 {
1155 struct lttng_event_notifier *event_notifier;
1156
1157 mutex_lock(&sessions_mutex);
1158 event_notifier = _lttng_event_notifier_create(event_desc, id,
1159 event_notifier_group, event_notifier_param, filter, itype);
1160 mutex_unlock(&sessions_mutex);
1161 return event_notifier;
1162 }
1163
1164 /* Only used for tracepoints for now. */
1165 static
1166 void register_event(struct lttng_event *event)
1167 {
1168 const struct lttng_event_desc *desc;
1169 int ret = -EINVAL;
1170
1171 if (event->registered)
1172 return;
1173
1174 desc = event->desc;
1175 switch (event->instrumentation) {
1176 case LTTNG_KERNEL_TRACEPOINT:
1177 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
1178 desc->probe_callback,
1179 event);
1180 break;
1181 case LTTNG_KERNEL_SYSCALL:
1182 ret = lttng_syscall_filter_enable(event->chan, event);
1183 break;
1184 case LTTNG_KERNEL_KPROBE:
1185 case LTTNG_KERNEL_UPROBE:
1186 case LTTNG_KERNEL_KRETPROBE:
1187 case LTTNG_KERNEL_NOOP:
1188 ret = 0;
1189 break;
1190 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1191 default:
1192 WARN_ON_ONCE(1);
1193 }
1194 if (!ret)
1195 event->registered = 1;
1196 }
1197
1198 /*
1199 * Only used internally at session destruction.
1200 */
1201 int _lttng_event_unregister(struct lttng_event *event)
1202 {
1203 const struct lttng_event_desc *desc;
1204 int ret = -EINVAL;
1205
1206 if (!event->registered)
1207 return 0;
1208
1209 desc = event->desc;
1210 switch (event->instrumentation) {
1211 case LTTNG_KERNEL_TRACEPOINT:
1212 ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname,
1213 event->desc->probe_callback,
1214 event);
1215 break;
1216 case LTTNG_KERNEL_KPROBE:
1217 lttng_kprobes_unregister_event(event);
1218 ret = 0;
1219 break;
1220 case LTTNG_KERNEL_KRETPROBE:
1221 lttng_kretprobes_unregister(event);
1222 ret = 0;
1223 break;
1224 case LTTNG_KERNEL_SYSCALL:
1225 ret = lttng_syscall_filter_disable(event->chan, event);
1226 break;
1227 case LTTNG_KERNEL_NOOP:
1228 ret = 0;
1229 break;
1230 case LTTNG_KERNEL_UPROBE:
1231 lttng_uprobes_unregister_event(event);
1232 ret = 0;
1233 break;
1234 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1235 default:
1236 WARN_ON_ONCE(1);
1237 }
1238 if (!ret)
1239 event->registered = 0;
1240 return ret;
1241 }
1242
1243 /* Only used for tracepoints for now. */
1244 static
1245 void register_event_notifier(struct lttng_event_notifier *event_notifier)
1246 {
1247 const struct lttng_event_desc *desc;
1248 int ret = -EINVAL;
1249
1250 if (event_notifier->registered)
1251 return;
1252
1253 desc = event_notifier->desc;
1254 switch (event_notifier->instrumentation) {
1255 case LTTNG_KERNEL_TRACEPOINT:
1256 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
1257 desc->event_notifier_callback,
1258 event_notifier);
1259 break;
1260 case LTTNG_KERNEL_KPROBE:
1261 case LTTNG_KERNEL_UPROBE:
1262 ret = 0;
1263 break;
1264 case LTTNG_KERNEL_SYSCALL:
1265 case LTTNG_KERNEL_KRETPROBE:
1266 case LTTNG_KERNEL_FUNCTION:
1267 case LTTNG_KERNEL_NOOP:
1268 default:
1269 WARN_ON_ONCE(1);
1270 }
1271 if (!ret)
1272 event_notifier->registered = 1;
1273 }
1274
1275 static
1276 int _lttng_event_notifier_unregister(
1277 struct lttng_event_notifier *event_notifier)
1278 {
1279 const struct lttng_event_desc *desc;
1280 int ret = -EINVAL;
1281
1282 if (!event_notifier->registered)
1283 return 0;
1284
1285 desc = event_notifier->desc;
1286 switch (event_notifier->instrumentation) {
1287 case LTTNG_KERNEL_TRACEPOINT:
1288 ret = lttng_wrapper_tracepoint_probe_unregister(event_notifier->desc->kname,
1289 event_notifier->desc->event_notifier_callback,
1290 event_notifier);
1291 break;
1292 case LTTNG_KERNEL_KPROBE:
1293 lttng_kprobes_unregister_event_notifier(event_notifier);
1294 ret = 0;
1295 break;
1296 case LTTNG_KERNEL_UPROBE:
1297 lttng_uprobes_unregister_event_notifier(event_notifier);
1298 ret = 0;
1299 break;
1300 case LTTNG_KERNEL_KRETPROBE:
1301 case LTTNG_KERNEL_FUNCTION:
1302 case LTTNG_KERNEL_SYSCALL:
1303 case LTTNG_KERNEL_NOOP:
1304 default:
1305 WARN_ON_ONCE(1);
1306 }
1307 if (!ret)
1308 event_notifier->registered = 0;
1309 return ret;
1310 }
1311
1312 /*
1313 * Only used internally at session destruction.
1314 */
1315 static
1316 void _lttng_event_destroy(struct lttng_event *event)
1317 {
1318 switch (event->instrumentation) {
1319 case LTTNG_KERNEL_TRACEPOINT:
1320 lttng_event_desc_put(event->desc);
1321 break;
1322 case LTTNG_KERNEL_KPROBE:
1323 module_put(event->desc->owner);
1324 lttng_kprobes_destroy_event_private(event);
1325 break;
1326 case LTTNG_KERNEL_KRETPROBE:
1327 module_put(event->desc->owner);
1328 lttng_kretprobes_destroy_private(event);
1329 break;
1330 case LTTNG_KERNEL_NOOP:
1331 case LTTNG_KERNEL_SYSCALL:
1332 break;
1333 case LTTNG_KERNEL_UPROBE:
1334 module_put(event->desc->owner);
1335 lttng_uprobes_destroy_event_private(event);
1336 break;
1337 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
1338 default:
1339 WARN_ON_ONCE(1);
1340 }
1341 list_del(&event->list);
1342 lttng_destroy_context(event->ctx);
1343 kmem_cache_free(event_cache, event);
1344 }
1345
1346 /*
1347 * Only used internally at session destruction.
1348 */
1349 static
1350 void _lttng_event_notifier_destroy(struct lttng_event_notifier *event_notifier)
1351 {
1352 switch (event_notifier->instrumentation) {
1353 case LTTNG_KERNEL_TRACEPOINT:
1354 lttng_event_desc_put(event_notifier->desc);
1355 break;
1356 case LTTNG_KERNEL_KPROBE:
1357 module_put(event_notifier->desc->owner);
1358 lttng_kprobes_destroy_event_notifier_private(event_notifier);
1359 break;
1360 case LTTNG_KERNEL_UPROBE:
1361 module_put(event_notifier->desc->owner);
1362 lttng_uprobes_destroy_event_notifier_private(event_notifier);
1363 break;
1364 case LTTNG_KERNEL_KRETPROBE:
1365 case LTTNG_KERNEL_FUNCTION:
1366 case LTTNG_KERNEL_NOOP:
1367 case LTTNG_KERNEL_SYSCALL:
1368 default:
1369 WARN_ON_ONCE(1);
1370 }
1371 list_del(&event_notifier->list);
1372 kmem_cache_free(event_notifier_cache, event_notifier);
1373 }
1374
1375 struct lttng_id_tracker *get_tracker(struct lttng_session *session,
1376 enum tracker_type tracker_type)
1377 {
1378 switch (tracker_type) {
1379 case TRACKER_PID:
1380 return &session->pid_tracker;
1381 case TRACKER_VPID:
1382 return &session->vpid_tracker;
1383 case TRACKER_UID:
1384 return &session->uid_tracker;
1385 case TRACKER_VUID:
1386 return &session->vuid_tracker;
1387 case TRACKER_GID:
1388 return &session->gid_tracker;
1389 case TRACKER_VGID:
1390 return &session->vgid_tracker;
1391 default:
1392 WARN_ON_ONCE(1);
1393 return NULL;
1394 }
1395 }
1396
1397 int lttng_session_track_id(struct lttng_session *session,
1398 enum tracker_type tracker_type, int id)
1399 {
1400 struct lttng_id_tracker *tracker;
1401 int ret;
1402
1403 tracker = get_tracker(session, tracker_type);
1404 if (!tracker)
1405 return -EINVAL;
1406 if (id < -1)
1407 return -EINVAL;
1408 mutex_lock(&sessions_mutex);
1409 if (id == -1) {
1410 /* track all ids: destroy tracker. */
1411 lttng_id_tracker_destroy(tracker, true);
1412 ret = 0;
1413 } else {
1414 ret = lttng_id_tracker_add(tracker, id);
1415 }
1416 mutex_unlock(&sessions_mutex);
1417 return ret;
1418 }
1419
1420 int lttng_session_untrack_id(struct lttng_session *session,
1421 enum tracker_type tracker_type, int id)
1422 {
1423 struct lttng_id_tracker *tracker;
1424 int ret;
1425
1426 tracker = get_tracker(session, tracker_type);
1427 if (!tracker)
1428 return -EINVAL;
1429 if (id < -1)
1430 return -EINVAL;
1431 mutex_lock(&sessions_mutex);
1432 if (id == -1) {
1433 /* untrack all ids: replace by empty tracker. */
1434 ret = lttng_id_tracker_empty_set(tracker);
1435 } else {
1436 ret = lttng_id_tracker_del(tracker, id);
1437 }
1438 mutex_unlock(&sessions_mutex);
1439 return ret;
1440 }
1441
1442 static
1443 void *id_list_start(struct seq_file *m, loff_t *pos)
1444 {
1445 struct lttng_id_tracker *id_tracker = m->private;
1446 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1447 struct lttng_id_hash_node *e;
1448 int iter = 0, i;
1449
1450 mutex_lock(&sessions_mutex);
1451 if (id_tracker_p) {
1452 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1453 struct hlist_head *head = &id_tracker_p->id_hash[i];
1454
1455 lttng_hlist_for_each_entry(e, head, hlist) {
1456 if (iter++ >= *pos)
1457 return e;
1458 }
1459 }
1460 } else {
1461 /* ID tracker disabled. */
1462 if (iter >= *pos && iter == 0) {
1463 return id_tracker_p; /* empty tracker */
1464 }
1465 iter++;
1466 }
1467 /* End of list */
1468 return NULL;
1469 }
1470
1471 /* Called with sessions_mutex held. */
1472 static
1473 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1474 {
1475 struct lttng_id_tracker *id_tracker = m->private;
1476 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1477 struct lttng_id_hash_node *e;
1478 int iter = 0, i;
1479
1480 (*ppos)++;
1481 if (id_tracker_p) {
1482 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1483 struct hlist_head *head = &id_tracker_p->id_hash[i];
1484
1485 lttng_hlist_for_each_entry(e, head, hlist) {
1486 if (iter++ >= *ppos)
1487 return e;
1488 }
1489 }
1490 } else {
1491 /* ID tracker disabled. */
1492 if (iter >= *ppos && iter == 0)
1493 return p; /* empty tracker */
1494 iter++;
1495 }
1496
1497 /* End of list */
1498 return NULL;
1499 }
1500
1501 static
1502 void id_list_stop(struct seq_file *m, void *p)
1503 {
1504 mutex_unlock(&sessions_mutex);
1505 }
1506
1507 static
1508 int id_list_show(struct seq_file *m, void *p)
1509 {
1510 struct lttng_id_tracker *id_tracker = m->private;
1511 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1512 int id;
1513
1514 if (p == id_tracker_p) {
1515 /* Tracker disabled. */
1516 id = -1;
1517 } else {
1518 const struct lttng_id_hash_node *e = p;
1519
1520 id = lttng_id_tracker_get_node_id(e);
1521 }
1522 switch (id_tracker->tracker_type) {
1523 case TRACKER_PID:
1524 seq_printf(m, "process { pid = %d; };\n", id);
1525 break;
1526 case TRACKER_VPID:
1527 seq_printf(m, "process { vpid = %d; };\n", id);
1528 break;
1529 case TRACKER_UID:
1530 seq_printf(m, "user { uid = %d; };\n", id);
1531 break;
1532 case TRACKER_VUID:
1533 seq_printf(m, "user { vuid = %d; };\n", id);
1534 break;
1535 case TRACKER_GID:
1536 seq_printf(m, "group { gid = %d; };\n", id);
1537 break;
1538 case TRACKER_VGID:
1539 seq_printf(m, "group { vgid = %d; };\n", id);
1540 break;
1541 default:
1542 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1543 }
1544 return 0;
1545 }
1546
1547 static
1548 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1549 .start = id_list_start,
1550 .next = id_list_next,
1551 .stop = id_list_stop,
1552 .show = id_list_show,
1553 };
1554
1555 static
1556 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1557 {
1558 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1559 }
1560
1561 static
1562 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1563 {
1564 struct seq_file *m = file->private_data;
1565 struct lttng_id_tracker *id_tracker = m->private;
1566 int ret;
1567
1568 WARN_ON_ONCE(!id_tracker);
1569 ret = seq_release(inode, file);
1570 if (!ret)
1571 fput(id_tracker->session->file);
1572 return ret;
1573 }
1574
1575 const struct file_operations lttng_tracker_ids_list_fops = {
1576 .owner = THIS_MODULE,
1577 .open = lttng_tracker_ids_list_open,
1578 .read = seq_read,
1579 .llseek = seq_lseek,
1580 .release = lttng_tracker_ids_list_release,
1581 };
1582
1583 int lttng_session_list_tracker_ids(struct lttng_session *session,
1584 enum tracker_type tracker_type)
1585 {
1586 struct file *tracker_ids_list_file;
1587 struct seq_file *m;
1588 int file_fd, ret;
1589
1590 file_fd = lttng_get_unused_fd();
1591 if (file_fd < 0) {
1592 ret = file_fd;
1593 goto fd_error;
1594 }
1595
1596 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1597 &lttng_tracker_ids_list_fops,
1598 NULL, O_RDWR);
1599 if (IS_ERR(tracker_ids_list_file)) {
1600 ret = PTR_ERR(tracker_ids_list_file);
1601 goto file_error;
1602 }
1603 if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
1604 ret = -EOVERFLOW;
1605 goto refcount_error;
1606 }
1607 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1608 if (ret < 0)
1609 goto open_error;
1610 m = tracker_ids_list_file->private_data;
1611
1612 m->private = get_tracker(session, tracker_type);
1613 BUG_ON(!m->private);
1614 fd_install(file_fd, tracker_ids_list_file);
1615
1616 return file_fd;
1617
1618 open_error:
1619 atomic_long_dec(&session->file->f_count);
1620 refcount_error:
1621 fput(tracker_ids_list_file);
1622 file_error:
1623 put_unused_fd(file_fd);
1624 fd_error:
1625 return ret;
1626 }
1627
1628 /*
1629 * Enabler management.
1630 */
1631 static
1632 int lttng_match_enabler_star_glob(const char *desc_name,
1633 const char *pattern)
1634 {
1635 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1636 desc_name, LTTNG_SIZE_MAX))
1637 return 0;
1638 return 1;
1639 }
1640
1641 static
1642 int lttng_match_enabler_name(const char *desc_name,
1643 const char *name)
1644 {
1645 if (strcmp(desc_name, name))
1646 return 0;
1647 return 1;
1648 }
1649
1650 static
1651 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
1652 struct lttng_enabler *enabler)
1653 {
1654 const char *desc_name, *enabler_name;
1655 bool compat = false, entry = false;
1656
1657 enabler_name = enabler->event_param.name;
1658 switch (enabler->event_param.instrumentation) {
1659 case LTTNG_KERNEL_TRACEPOINT:
1660 desc_name = desc->name;
1661 switch (enabler->format_type) {
1662 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1663 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1664 case LTTNG_ENABLER_FORMAT_NAME:
1665 return lttng_match_enabler_name(desc_name, enabler_name);
1666 default:
1667 return -EINVAL;
1668 }
1669 break;
1670 case LTTNG_KERNEL_SYSCALL:
1671 desc_name = desc->name;
1672 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1673 desc_name += strlen("compat_");
1674 compat = true;
1675 }
1676 if (!strncmp(desc_name, "syscall_exit_",
1677 strlen("syscall_exit_"))) {
1678 desc_name += strlen("syscall_exit_");
1679 } else if (!strncmp(desc_name, "syscall_entry_",
1680 strlen("syscall_entry_"))) {
1681 desc_name += strlen("syscall_entry_");
1682 entry = true;
1683 } else {
1684 WARN_ON_ONCE(1);
1685 return -EINVAL;
1686 }
1687 switch (enabler->event_param.u.syscall.entryexit) {
1688 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1689 break;
1690 case LTTNG_KERNEL_SYSCALL_ENTRY:
1691 if (!entry)
1692 return 0;
1693 break;
1694 case LTTNG_KERNEL_SYSCALL_EXIT:
1695 if (entry)
1696 return 0;
1697 break;
1698 default:
1699 return -EINVAL;
1700 }
1701 switch (enabler->event_param.u.syscall.abi) {
1702 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1703 break;
1704 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1705 if (compat)
1706 return 0;
1707 break;
1708 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1709 if (!compat)
1710 return 0;
1711 break;
1712 default:
1713 return -EINVAL;
1714 }
1715 switch (enabler->event_param.u.syscall.match) {
1716 case LTTNG_SYSCALL_MATCH_NAME:
1717 switch (enabler->format_type) {
1718 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
1719 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1720 case LTTNG_ENABLER_FORMAT_NAME:
1721 return lttng_match_enabler_name(desc_name, enabler_name);
1722 default:
1723 return -EINVAL;
1724 }
1725 break;
1726 case LTTNG_SYSCALL_MATCH_NR:
1727 return -EINVAL; /* Not implemented. */
1728 default:
1729 return -EINVAL;
1730 }
1731 break;
1732 default:
1733 WARN_ON_ONCE(1);
1734 return -EINVAL;
1735 }
1736 }
1737
1738 static
1739 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
1740 struct lttng_event *event)
1741 {
1742 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
1743 event_enabler);
1744
1745 if (base_enabler->event_param.instrumentation != event->instrumentation)
1746 return 0;
1747 if (lttng_desc_match_enabler(event->desc, base_enabler)
1748 && event->chan == event_enabler->chan)
1749 return 1;
1750 else
1751 return 0;
1752 }
1753
1754 static
1755 int lttng_event_notifier_enabler_match_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler,
1756 struct lttng_event_notifier *event_notifier)
1757 {
1758 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(
1759 event_notifier_enabler);
1760
1761 if (base_enabler->event_param.instrumentation != event_notifier->instrumentation)
1762 return 0;
1763 if (lttng_desc_match_enabler(event_notifier->desc, base_enabler)
1764 && event_notifier->group == event_notifier_enabler->group
1765 && event_notifier->user_token == event_notifier_enabler->base.user_token)
1766 return 1;
1767 else
1768 return 0;
1769 }
1770
1771 static
1772 struct lttng_enabler_ref *lttng_enabler_ref(
1773 struct list_head *enablers_ref_list,
1774 struct lttng_enabler *enabler)
1775 {
1776 struct lttng_enabler_ref *enabler_ref;
1777
1778 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
1779 if (enabler_ref->ref == enabler)
1780 return enabler_ref;
1781 }
1782 return NULL;
1783 }
1784
1785 static
1786 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
1787 {
1788 struct lttng_session *session = event_enabler->chan->session;
1789 struct lttng_probe_desc *probe_desc;
1790 const struct lttng_event_desc *desc;
1791 int i;
1792 struct list_head *probe_list;
1793
1794 probe_list = lttng_get_probe_list_head();
1795 /*
1796 * For each probe event, if we find that a probe event matches
1797 * our enabler, create an associated lttng_event if not
1798 * already present.
1799 */
1800 list_for_each_entry(probe_desc, probe_list, head) {
1801 for (i = 0; i < probe_desc->nr_events; i++) {
1802 int found = 0;
1803 struct hlist_head *head;
1804 struct lttng_event *event;
1805
1806 desc = probe_desc->event_desc[i];
1807 if (!lttng_desc_match_enabler(desc,
1808 lttng_event_enabler_as_enabler(event_enabler)))
1809 continue;
1810
1811 /*
1812 * Check if already created.
1813 */
1814 head = utils_borrow_hash_table_bucket(
1815 session->events_ht.table, LTTNG_EVENT_HT_SIZE,
1816 desc->name);
1817 lttng_hlist_for_each_entry(event, head, hlist) {
1818 if (event->desc == desc
1819 && event->chan == event_enabler->chan)
1820 found = 1;
1821 }
1822 if (found)
1823 continue;
1824
1825 /*
1826 * We need to create an event for this
1827 * event probe.
1828 */
1829 event = _lttng_event_create(event_enabler->chan,
1830 NULL, NULL, desc,
1831 LTTNG_KERNEL_TRACEPOINT);
1832 if (!event) {
1833 printk(KERN_INFO "LTTng: Unable to create event %s\n",
1834 probe_desc->event_desc[i]->name);
1835 }
1836 }
1837 }
1838 }
1839
1840 static
1841 void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
1842 {
1843 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
1844 struct lttng_probe_desc *probe_desc;
1845 const struct lttng_event_desc *desc;
1846 int i;
1847 struct list_head *probe_list;
1848
1849 probe_list = lttng_get_probe_list_head();
1850 /*
1851 * For each probe event, if we find that a probe event matches
1852 * our enabler, create an associated lttng_event_notifier if not
1853 * already present.
1854 */
1855 list_for_each_entry(probe_desc, probe_list, head) {
1856 for (i = 0; i < probe_desc->nr_events; i++) {
1857 int found = 0;
1858 struct hlist_head *head;
1859 struct lttng_event_notifier *event_notifier;
1860
1861 desc = probe_desc->event_desc[i];
1862 if (!lttng_desc_match_enabler(desc,
1863 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
1864 continue;
1865
1866 /*
1867 * Check if already created.
1868 */
1869 head = utils_borrow_hash_table_bucket(
1870 event_notifier_group->event_notifiers_ht.table,
1871 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->name);
1872 lttng_hlist_for_each_entry(event_notifier, head, hlist) {
1873 if (event_notifier->desc == desc
1874 && event_notifier->user_token == event_notifier_enabler->base.user_token)
1875 found = 1;
1876 }
1877 if (found)
1878 continue;
1879
1880 /*
1881 * We need to create a event_notifier for this event probe.
1882 */
1883 event_notifier = _lttng_event_notifier_create(desc,
1884 event_notifier_enabler->base.user_token,
1885 event_notifier_group, NULL, NULL,
1886 LTTNG_KERNEL_TRACEPOINT);
1887 if (IS_ERR(event_notifier)) {
1888 printk(KERN_INFO "Unable to create event_notifier %s\n",
1889 probe_desc->event_desc[i]->name);
1890 }
1891 }
1892 }
1893 }
1894
1895 static
1896 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
1897 {
1898 int ret;
1899
1900 ret = lttng_syscalls_register(event_enabler->chan, NULL);
1901 WARN_ON_ONCE(ret);
1902 }
1903
1904 /*
1905 * Create struct lttng_event if it is missing and present in the list of
1906 * tracepoint probes.
1907 * Should be called with sessions mutex held.
1908 */
1909 static
1910 void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
1911 {
1912 switch (event_enabler->base.event_param.instrumentation) {
1913 case LTTNG_KERNEL_TRACEPOINT:
1914 lttng_create_tracepoint_event_if_missing(event_enabler);
1915 break;
1916 case LTTNG_KERNEL_SYSCALL:
1917 lttng_create_syscall_event_if_missing(event_enabler);
1918 break;
1919 default:
1920 WARN_ON_ONCE(1);
1921 break;
1922 }
1923 }
1924
1925 /*
1926 * Create events associated with an event_enabler (if not already present),
1927 * and add backward reference from the event to the enabler.
1928 * Should be called with sessions mutex held.
1929 */
1930 static
1931 int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
1932 {
1933 struct lttng_channel *chan = event_enabler->chan;
1934 struct lttng_session *session = event_enabler->chan->session;
1935 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
1936 struct lttng_event *event;
1937
1938 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
1939 base_enabler->event_param.u.syscall.entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT &&
1940 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
1941 base_enabler->event_param.u.syscall.match == LTTNG_SYSCALL_MATCH_NAME &&
1942 !strcmp(base_enabler->event_param.name, "*")) {
1943 if (base_enabler->enabled)
1944 WRITE_ONCE(chan->syscall_all, 1);
1945 else
1946 WRITE_ONCE(chan->syscall_all, 0);
1947 }
1948
1949 /* First ensure that probe events are created for this enabler. */
1950 lttng_create_event_if_missing(event_enabler);
1951
1952 /* For each event matching event_enabler in session event list. */
1953 list_for_each_entry(event, &session->events, list) {
1954 struct lttng_enabler_ref *enabler_ref;
1955
1956 if (!lttng_event_enabler_match_event(event_enabler, event))
1957 continue;
1958 enabler_ref = lttng_enabler_ref(&event->enablers_ref_head,
1959 lttng_event_enabler_as_enabler(event_enabler));
1960 if (!enabler_ref) {
1961 /*
1962 * If no backward ref, create it.
1963 * Add backward ref from event to event_enabler.
1964 */
1965 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
1966 if (!enabler_ref)
1967 return -ENOMEM;
1968 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
1969 list_add(&enabler_ref->node,
1970 &event->enablers_ref_head);
1971 }
1972
1973 /*
1974 * Link filter bytecodes if not linked yet.
1975 */
1976 lttng_enabler_link_bytecode(event->desc,
1977 lttng_static_ctx,
1978 &event->bytecode_runtime_head,
1979 lttng_event_enabler_as_enabler(event_enabler));
1980
1981 /* TODO: merge event context. */
1982 }
1983 return 0;
1984 }
1985
1986 /*
1987 * Create struct lttng_event_notifier if it is missing and present in the list of
1988 * tracepoint probes.
1989 * Should be called with sessions mutex held.
1990 */
1991 static
1992 void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
1993 {
1994 switch (event_notifier_enabler->base.event_param.instrumentation) {
1995 case LTTNG_KERNEL_TRACEPOINT:
1996 lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
1997 break;
1998 default:
1999 WARN_ON_ONCE(1);
2000 break;
2001 }
2002 }
2003
2004 /*
2005 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2006 */
2007 static
2008 int lttng_event_notifier_enabler_ref_event_notifiers(struct lttng_event_notifier_enabler *event_notifier_enabler)
2009 {
2010 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2011 struct lttng_event_notifier *event_notifier;
2012
2013 /* First ensure that probe event_notifiers are created for this enabler. */
2014 lttng_create_event_notifier_if_missing(event_notifier_enabler);
2015
2016 /* Link the created event_notifier with its associated enabler. */
2017 list_for_each_entry(event_notifier, &event_notifier_group->event_notifiers_head, list) {
2018 struct lttng_enabler_ref *enabler_ref;
2019
2020 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier))
2021 continue;
2022
2023 enabler_ref = lttng_enabler_ref(&event_notifier->enablers_ref_head,
2024 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2025 if (!enabler_ref) {
2026 /*
2027 * If no backward ref, create it.
2028 * Add backward ref from event_notifier to enabler.
2029 */
2030 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2031 if (!enabler_ref)
2032 return -ENOMEM;
2033
2034 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2035 event_notifier_enabler);
2036 list_add(&enabler_ref->node,
2037 &event_notifier->enablers_ref_head);
2038 }
2039
2040 /*
2041 * Link filter bytecodes if not linked yet.
2042 */
2043 lttng_enabler_link_bytecode(event_notifier->desc,
2044 lttng_static_ctx, &event_notifier->bytecode_runtime_head,
2045 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2046 }
2047 return 0;
2048 }
2049
2050 /*
2051 * Called at module load: connect the probe on all enablers matching
2052 * this event.
2053 * Called with sessions lock held.
2054 */
2055 int lttng_fix_pending_events(void)
2056 {
2057 struct lttng_session *session;
2058
2059 list_for_each_entry(session, &sessions, list)
2060 lttng_session_lazy_sync_event_enablers(session);
2061 return 0;
2062 }
2063
2064 static bool lttng_event_notifier_group_has_active_event_notifiers(
2065 struct lttng_event_notifier_group *event_notifier_group)
2066 {
2067 struct lttng_event_notifier_enabler *event_notifier_enabler;
2068
2069 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2070 node) {
2071 if (event_notifier_enabler->base.enabled)
2072 return true;
2073 }
2074 return false;
2075 }
2076
2077 bool lttng_event_notifier_active(void)
2078 {
2079 struct lttng_event_notifier_group *event_notifier_group;
2080
2081 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2082 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2083 return true;
2084 }
2085 return false;
2086 }
2087
2088 int lttng_fix_pending_event_notifiers(void)
2089 {
2090 struct lttng_event_notifier_group *event_notifier_group;
2091
2092 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2093 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2094 return 0;
2095 }
2096
2097 struct lttng_event_enabler *lttng_event_enabler_create(
2098 enum lttng_enabler_format_type format_type,
2099 struct lttng_kernel_event *event_param,
2100 struct lttng_channel *chan)
2101 {
2102 struct lttng_event_enabler *event_enabler;
2103
2104 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2105 if (!event_enabler)
2106 return NULL;
2107 event_enabler->base.format_type = format_type;
2108 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2109 memcpy(&event_enabler->base.event_param, event_param,
2110 sizeof(event_enabler->base.event_param));
2111 event_enabler->chan = chan;
2112 /* ctx left NULL */
2113 event_enabler->base.enabled = 0;
2114 event_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2115 mutex_lock(&sessions_mutex);
2116 list_add(&event_enabler->node, &event_enabler->chan->session->enablers_head);
2117 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2118 mutex_unlock(&sessions_mutex);
2119 return event_enabler;
2120 }
2121
2122 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2123 {
2124 mutex_lock(&sessions_mutex);
2125 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2126 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2127 mutex_unlock(&sessions_mutex);
2128 return 0;
2129 }
2130
2131 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2132 {
2133 mutex_lock(&sessions_mutex);
2134 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2135 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2136 mutex_unlock(&sessions_mutex);
2137 return 0;
2138 }
2139
2140 static
2141 int lttng_enabler_attach_bytecode(struct lttng_enabler *enabler,
2142 struct lttng_kernel_filter_bytecode __user *bytecode)
2143 {
2144 struct lttng_filter_bytecode_node *bytecode_node;
2145 uint32_t bytecode_len;
2146 int ret;
2147
2148 ret = get_user(bytecode_len, &bytecode->len);
2149 if (ret)
2150 return ret;
2151 bytecode_node = kzalloc(sizeof(*bytecode_node) + bytecode_len,
2152 GFP_KERNEL);
2153 if (!bytecode_node)
2154 return -ENOMEM;
2155 ret = copy_from_user(&bytecode_node->bc, bytecode,
2156 sizeof(*bytecode) + bytecode_len);
2157 if (ret)
2158 goto error_free;
2159
2160 bytecode_node->enabler = enabler;
2161 /* Enforce length based on allocated size */
2162 bytecode_node->bc.len = bytecode_len;
2163 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2164
2165 return 0;
2166
2167 error_free:
2168 kfree(bytecode_node);
2169 return ret;
2170 }
2171
2172 int lttng_event_enabler_attach_bytecode(struct lttng_event_enabler *event_enabler,
2173 struct lttng_kernel_filter_bytecode __user *bytecode)
2174 {
2175 int ret;
2176 ret = lttng_enabler_attach_bytecode(
2177 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2178 if (ret)
2179 goto error;
2180
2181 lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
2182 return 0;
2183
2184 error:
2185 return ret;
2186 }
2187
2188 int lttng_event_add_callsite(struct lttng_event *event,
2189 struct lttng_kernel_event_callsite __user *callsite)
2190 {
2191
2192 switch (event->instrumentation) {
2193 case LTTNG_KERNEL_UPROBE:
2194 return lttng_uprobes_event_add_callsite(event, callsite);
2195 default:
2196 return -EINVAL;
2197 }
2198 }
2199
2200 int lttng_event_enabler_attach_context(struct lttng_event_enabler *event_enabler,
2201 struct lttng_kernel_context *context_param)
2202 {
2203 return -ENOSYS;
2204 }
2205
2206 static
2207 void lttng_enabler_destroy(struct lttng_enabler *enabler)
2208 {
2209 struct lttng_filter_bytecode_node *filter_node, *tmp_filter_node;
2210
2211 /* Destroy filter bytecode */
2212 list_for_each_entry_safe(filter_node, tmp_filter_node,
2213 &enabler->filter_bytecode_head, node) {
2214 kfree(filter_node);
2215 }
2216 }
2217
2218 static
2219 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2220 {
2221 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2222
2223 /* Destroy contexts */
2224 lttng_destroy_context(event_enabler->ctx);
2225
2226 list_del(&event_enabler->node);
2227 kfree(event_enabler);
2228 }
2229
2230 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2231 struct lttng_event_notifier_group *event_notifier_group,
2232 enum lttng_enabler_format_type format_type,
2233 struct lttng_kernel_event_notifier *event_notifier_param)
2234 {
2235 struct lttng_event_notifier_enabler *event_notifier_enabler;
2236
2237 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2238 if (!event_notifier_enabler)
2239 return NULL;
2240
2241 event_notifier_enabler->base.format_type = format_type;
2242 INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
2243
2244 memcpy(&event_notifier_enabler->base.event_param.name, event_notifier_param->event.name,
2245 sizeof(event_notifier_enabler->base.event_param.name));
2246 event_notifier_enabler->base.event_param.instrumentation = event_notifier_param->event.instrumentation;
2247 event_notifier_enabler->base.evtype = LTTNG_TYPE_ENABLER;
2248
2249 event_notifier_enabler->base.enabled = 0;
2250 event_notifier_enabler->base.user_token = event_notifier_param->event.token;
2251 event_notifier_enabler->group = event_notifier_group;
2252
2253 mutex_lock(&sessions_mutex);
2254 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2255 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2256
2257 mutex_unlock(&sessions_mutex);
2258
2259 return event_notifier_enabler;
2260 }
2261
2262 int lttng_event_notifier_enabler_enable(
2263 struct lttng_event_notifier_enabler *event_notifier_enabler)
2264 {
2265 mutex_lock(&sessions_mutex);
2266 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2267 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2268 mutex_unlock(&sessions_mutex);
2269 return 0;
2270 }
2271
2272 int lttng_event_notifier_enabler_disable(
2273 struct lttng_event_notifier_enabler *event_notifier_enabler)
2274 {
2275 mutex_lock(&sessions_mutex);
2276 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2277 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2278 mutex_unlock(&sessions_mutex);
2279 return 0;
2280 }
2281
2282 int lttng_event_notifier_enabler_attach_bytecode(
2283 struct lttng_event_notifier_enabler *event_notifier_enabler,
2284 struct lttng_kernel_filter_bytecode __user *bytecode)
2285 {
2286 int ret;
2287
2288 ret = lttng_enabler_attach_bytecode(
2289 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
2290 bytecode);
2291 if (ret)
2292 goto error;
2293
2294 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2295 return 0;
2296
2297 error:
2298 return ret;
2299 }
2300
2301 int lttng_event_notifier_add_callsite(struct lttng_event_notifier *event_notifier,
2302 struct lttng_kernel_event_callsite __user *callsite)
2303 {
2304
2305 switch (event_notifier->instrumentation) {
2306 case LTTNG_KERNEL_UPROBE:
2307 return lttng_uprobes_event_notifier_add_callsite(event_notifier,
2308 callsite);
2309 default:
2310 return -EINVAL;
2311 }
2312 }
2313
2314 int lttng_event_notifier_enabler_attach_context(
2315 struct lttng_event_notifier_enabler *event_notifier_enabler,
2316 struct lttng_kernel_context *context_param)
2317 {
2318 return -ENOSYS;
2319 }
2320
2321 static
2322 void lttng_event_notifier_enabler_destroy(
2323 struct lttng_event_notifier_enabler *event_notifier_enabler)
2324 {
2325 if (!event_notifier_enabler) {
2326 return;
2327 }
2328
2329 list_del(&event_notifier_enabler->node);
2330
2331 lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2332 kfree(event_notifier_enabler);
2333 }
2334
2335 /*
2336 * lttng_session_sync_event_enablers should be called just before starting a
2337 * session.
2338 * Should be called with sessions mutex held.
2339 */
2340 static
2341 void lttng_session_sync_event_enablers(struct lttng_session *session)
2342 {
2343 struct lttng_event_enabler *event_enabler;
2344 struct lttng_event *event;
2345
2346 list_for_each_entry(event_enabler, &session->enablers_head, node)
2347 lttng_event_enabler_ref_events(event_enabler);
2348 /*
2349 * For each event, if at least one of its enablers is enabled,
2350 * and its channel and session transient states are enabled, we
2351 * enable the event, else we disable it.
2352 */
2353 list_for_each_entry(event, &session->events, list) {
2354 struct lttng_enabler_ref *enabler_ref;
2355 struct lttng_bytecode_runtime *runtime;
2356 int enabled = 0, has_enablers_without_bytecode = 0;
2357
2358 switch (event->instrumentation) {
2359 case LTTNG_KERNEL_TRACEPOINT:
2360 case LTTNG_KERNEL_SYSCALL:
2361 /* Enable events */
2362 list_for_each_entry(enabler_ref,
2363 &event->enablers_ref_head, node) {
2364 if (enabler_ref->ref->enabled) {
2365 enabled = 1;
2366 break;
2367 }
2368 }
2369 break;
2370 default:
2371 /* Not handled with lazy sync. */
2372 continue;
2373 }
2374 /*
2375 * Enabled state is based on union of enablers, with
2376 * intesection of session and channel transient enable
2377 * states.
2378 */
2379 enabled = enabled && session->tstate && event->chan->tstate;
2380
2381 WRITE_ONCE(event->enabled, enabled);
2382 /*
2383 * Sync tracepoint registration with event enabled
2384 * state.
2385 */
2386 if (enabled) {
2387 register_event(event);
2388 } else {
2389 _lttng_event_unregister(event);
2390 }
2391
2392 /* Check if has enablers without bytecode enabled */
2393 list_for_each_entry(enabler_ref,
2394 &event->enablers_ref_head, node) {
2395 if (enabler_ref->ref->enabled
2396 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2397 has_enablers_without_bytecode = 1;
2398 break;
2399 }
2400 }
2401 event->has_enablers_without_bytecode =
2402 has_enablers_without_bytecode;
2403
2404 /* Enable filters */
2405 list_for_each_entry(runtime,
2406 &event->bytecode_runtime_head, node)
2407 lttng_filter_sync_state(runtime);
2408 }
2409 }
2410
2411 /*
2412 * Apply enablers to session events, adding events to session if need
2413 * be. It is required after each modification applied to an active
2414 * session, and right before session "start".
2415 * "lazy" sync means we only sync if required.
2416 * Should be called with sessions mutex held.
2417 */
2418 static
2419 void lttng_session_lazy_sync_event_enablers(struct lttng_session *session)
2420 {
2421 /* We can skip if session is not active */
2422 if (!session->active)
2423 return;
2424 lttng_session_sync_event_enablers(session);
2425 }
2426
2427 static
2428 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2429 {
2430 struct lttng_event_notifier_enabler *event_notifier_enabler;
2431 struct lttng_event_notifier *event_notifier;
2432
2433 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2434 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2435
2436 /*
2437 * For each event_notifier, if at least one of its enablers is enabled,
2438 * we enable the event_notifier, else we disable it.
2439 */
2440 list_for_each_entry(event_notifier, &event_notifier_group->event_notifiers_head, list) {
2441 struct lttng_enabler_ref *enabler_ref;
2442 struct lttng_bytecode_runtime *runtime;
2443 int enabled = 0, has_enablers_without_bytecode = 0;
2444
2445 switch (event_notifier->instrumentation) {
2446 case LTTNG_KERNEL_TRACEPOINT:
2447 case LTTNG_KERNEL_SYSCALL:
2448 /* Enable event_notifiers */
2449 list_for_each_entry(enabler_ref,
2450 &event_notifier->enablers_ref_head, node) {
2451 if (enabler_ref->ref->enabled) {
2452 enabled = 1;
2453 break;
2454 }
2455 }
2456 break;
2457 default:
2458 /* Not handled with sync. */
2459 continue;
2460 }
2461
2462 WRITE_ONCE(event_notifier->enabled, enabled);
2463 /*
2464 * Sync tracepoint registration with event_notifier enabled
2465 * state.
2466 */
2467 if (enabled) {
2468 if (!event_notifier->registered)
2469 register_event_notifier(event_notifier);
2470 } else {
2471 if (event_notifier->registered)
2472 _lttng_event_notifier_unregister(event_notifier);
2473 }
2474
2475 /* Check if has enablers without bytecode enabled */
2476 list_for_each_entry(enabler_ref,
2477 &event_notifier->enablers_ref_head, node) {
2478 if (enabler_ref->ref->enabled
2479 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2480 has_enablers_without_bytecode = 1;
2481 break;
2482 }
2483 }
2484 event_notifier->has_enablers_without_bytecode =
2485 has_enablers_without_bytecode;
2486
2487 /* Enable filters */
2488 list_for_each_entry(runtime,
2489 &event_notifier->bytecode_runtime_head, node)
2490 lttng_filter_sync_state(runtime);
2491 }
2492 }
2493
2494 /*
2495 * Serialize at most one packet worth of metadata into a metadata
2496 * channel.
2497 * We grab the metadata cache mutex to get exclusive access to our metadata
2498 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2499 * allows us to do racy operations such as looking for remaining space left in
2500 * packet and write, since mutual exclusion protects us from concurrent writes.
2501 * Mutual exclusion on the metadata cache allow us to read the cache content
2502 * without racing against reallocation of the cache by updates.
2503 * Returns the number of bytes written in the channel, 0 if no data
2504 * was written and a negative value on error.
2505 */
2506 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2507 struct channel *chan, bool *coherent)
2508 {
2509 struct lib_ring_buffer_ctx ctx;
2510 int ret = 0;
2511 size_t len, reserve_len;
2512
2513 /*
2514 * Ensure we support mutiple get_next / put sequences followed by
2515 * put_next. The metadata cache lock protects reading the metadata
2516 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2517 * "flush" operations on the buffer invoked by different processes.
2518 * Moreover, since the metadata cache memory can be reallocated, we
2519 * need to have exclusive access against updates even though we only
2520 * read it.
2521 */
2522 mutex_lock(&stream->metadata_cache->lock);
2523 WARN_ON(stream->metadata_in < stream->metadata_out);
2524 if (stream->metadata_in != stream->metadata_out)
2525 goto end;
2526
2527 /* Metadata regenerated, change the version. */
2528 if (stream->metadata_cache->version != stream->version)
2529 stream->version = stream->metadata_cache->version;
2530
2531 len = stream->metadata_cache->metadata_written -
2532 stream->metadata_in;
2533 if (!len)
2534 goto end;
2535 reserve_len = min_t(size_t,
2536 stream->transport->ops.packet_avail_size(chan),
2537 len);
2538 lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
2539 sizeof(char), -1);
2540 /*
2541 * If reservation failed, return an error to the caller.
2542 */
2543 ret = stream->transport->ops.event_reserve(&ctx, 0);
2544 if (ret != 0) {
2545 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2546 stream->coherent = false;
2547 goto end;
2548 }
2549 stream->transport->ops.event_write(&ctx,
2550 stream->metadata_cache->data + stream->metadata_in,
2551 reserve_len);
2552 stream->transport->ops.event_commit(&ctx);
2553 stream->metadata_in += reserve_len;
2554 if (reserve_len < len)
2555 stream->coherent = false;
2556 else
2557 stream->coherent = true;
2558 ret = reserve_len;
2559
2560 end:
2561 if (coherent)
2562 *coherent = stream->coherent;
2563 mutex_unlock(&stream->metadata_cache->lock);
2564 return ret;
2565 }
2566
2567 static
2568 void lttng_metadata_begin(struct lttng_session *session)
2569 {
2570 if (atomic_inc_return(&session->metadata_cache->producing) == 1)
2571 mutex_lock(&session->metadata_cache->lock);
2572 }
2573
2574 static
2575 void lttng_metadata_end(struct lttng_session *session)
2576 {
2577 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2578 if (atomic_dec_return(&session->metadata_cache->producing) == 0) {
2579 struct lttng_metadata_stream *stream;
2580
2581 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
2582 wake_up_interruptible(&stream->read_wait);
2583 mutex_unlock(&session->metadata_cache->lock);
2584 }
2585 }
2586
2587 /*
2588 * Write the metadata to the metadata cache.
2589 * Must be called with sessions_mutex held.
2590 * The metadata cache lock protects us from concurrent read access from
2591 * thread outputting metadata content to ring buffer.
2592 * The content of the printf is printed as a single atomic metadata
2593 * transaction.
2594 */
2595 int lttng_metadata_printf(struct lttng_session *session,
2596 const char *fmt, ...)
2597 {
2598 char *str;
2599 size_t len;
2600 va_list ap;
2601
2602 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2603
2604 va_start(ap, fmt);
2605 str = kvasprintf(GFP_KERNEL, fmt, ap);
2606 va_end(ap);
2607 if (!str)
2608 return -ENOMEM;
2609
2610 len = strlen(str);
2611 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
2612 if (session->metadata_cache->metadata_written + len >
2613 session->metadata_cache->cache_alloc) {
2614 char *tmp_cache_realloc;
2615 unsigned int tmp_cache_alloc_size;
2616
2617 tmp_cache_alloc_size = max_t(unsigned int,
2618 session->metadata_cache->cache_alloc + len,
2619 session->metadata_cache->cache_alloc << 1);
2620 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2621 if (!tmp_cache_realloc)
2622 goto err;
2623 if (session->metadata_cache->data) {
2624 memcpy(tmp_cache_realloc,
2625 session->metadata_cache->data,
2626 session->metadata_cache->cache_alloc);
2627 vfree(session->metadata_cache->data);
2628 }
2629
2630 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2631 session->metadata_cache->data = tmp_cache_realloc;
2632 }
2633 memcpy(session->metadata_cache->data +
2634 session->metadata_cache->metadata_written,
2635 str, len);
2636 session->metadata_cache->metadata_written += len;
2637 kfree(str);
2638
2639 return 0;
2640
2641 err:
2642 kfree(str);
2643 return -ENOMEM;
2644 }
2645
2646 static
2647 int print_tabs(struct lttng_session *session, size_t nesting)
2648 {
2649 size_t i;
2650
2651 for (i = 0; i < nesting; i++) {
2652 int ret;
2653
2654 ret = lttng_metadata_printf(session, " ");
2655 if (ret) {
2656 return ret;
2657 }
2658 }
2659 return 0;
2660 }
2661
2662 static
2663 int lttng_field_name_statedump(struct lttng_session *session,
2664 const struct lttng_event_field *field,
2665 size_t nesting)
2666 {
2667 return lttng_metadata_printf(session, " _%s;\n", field->name);
2668 }
2669
2670 static
2671 int _lttng_integer_type_statedump(struct lttng_session *session,
2672 const struct lttng_type *type,
2673 size_t nesting)
2674 {
2675 int ret;
2676
2677 WARN_ON_ONCE(type->atype != atype_integer);
2678 ret = print_tabs(session, nesting);
2679 if (ret)
2680 return ret;
2681 ret = lttng_metadata_printf(session,
2682 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
2683 type->u.integer.size,
2684 type->u.integer.alignment,
2685 type->u.integer.signedness,
2686 (type->u.integer.encoding == lttng_encode_none)
2687 ? "none"
2688 : (type->u.integer.encoding == lttng_encode_UTF8)
2689 ? "UTF8"
2690 : "ASCII",
2691 type->u.integer.base,
2692 #if __BYTE_ORDER == __BIG_ENDIAN
2693 type->u.integer.reverse_byte_order ? " byte_order = le;" : ""
2694 #else
2695 type->u.integer.reverse_byte_order ? " byte_order = be;" : ""
2696 #endif
2697 );
2698 return ret;
2699 }
2700
2701 /*
2702 * Must be called with sessions_mutex held.
2703 */
2704 static
2705 int _lttng_struct_type_statedump(struct lttng_session *session,
2706 const struct lttng_type *type,
2707 size_t nesting)
2708 {
2709 int ret;
2710 uint32_t i, nr_fields;
2711 unsigned int alignment;
2712
2713 WARN_ON_ONCE(type->atype != atype_struct_nestable);
2714
2715 ret = print_tabs(session, nesting);
2716 if (ret)
2717 return ret;
2718 ret = lttng_metadata_printf(session,
2719 "struct {\n");
2720 if (ret)
2721 return ret;
2722 nr_fields = type->u.struct_nestable.nr_fields;
2723 for (i = 0; i < nr_fields; i++) {
2724 const struct lttng_event_field *iter_field;
2725
2726 iter_field = &type->u.struct_nestable.fields[i];
2727 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
2728 if (ret)
2729 return ret;
2730 }
2731 ret = print_tabs(session, nesting);
2732 if (ret)
2733 return ret;
2734 alignment = type->u.struct_nestable.alignment;
2735 if (alignment) {
2736 ret = lttng_metadata_printf(session,
2737 "} align(%u)",
2738 alignment);
2739 } else {
2740 ret = lttng_metadata_printf(session,
2741 "}");
2742 }
2743 return ret;
2744 }
2745
2746 /*
2747 * Must be called with sessions_mutex held.
2748 */
2749 static
2750 int _lttng_struct_field_statedump(struct lttng_session *session,
2751 const struct lttng_event_field *field,
2752 size_t nesting)
2753 {
2754 int ret;
2755
2756 ret = _lttng_struct_type_statedump(session,
2757 &field->type, nesting);
2758 if (ret)
2759 return ret;
2760 return lttng_field_name_statedump(session, field, nesting);
2761 }
2762
2763 /*
2764 * Must be called with sessions_mutex held.
2765 */
2766 static
2767 int _lttng_variant_type_statedump(struct lttng_session *session,
2768 const struct lttng_type *type,
2769 size_t nesting)
2770 {
2771 int ret;
2772 uint32_t i, nr_choices;
2773
2774 WARN_ON_ONCE(type->atype != atype_variant_nestable);
2775 /*
2776 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
2777 */
2778 if (type->u.variant_nestable.alignment != 0)
2779 return -EINVAL;
2780 ret = print_tabs(session, nesting);
2781 if (ret)
2782 return ret;
2783 ret = lttng_metadata_printf(session,
2784 "variant <_%s> {\n",
2785 type->u.variant_nestable.tag_name);
2786 if (ret)
2787 return ret;
2788 nr_choices = type->u.variant_nestable.nr_choices;
2789 for (i = 0; i < nr_choices; i++) {
2790 const struct lttng_event_field *iter_field;
2791
2792 iter_field = &type->u.variant_nestable.choices[i];
2793 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
2794 if (ret)
2795 return ret;
2796 }
2797 ret = print_tabs(session, nesting);
2798 if (ret)
2799 return ret;
2800 ret = lttng_metadata_printf(session,
2801 "}");
2802 return ret;
2803 }
2804
2805 /*
2806 * Must be called with sessions_mutex held.
2807 */
2808 static
2809 int _lttng_variant_field_statedump(struct lttng_session *session,
2810 const struct lttng_event_field *field,
2811 size_t nesting)
2812 {
2813 int ret;
2814
2815 ret = _lttng_variant_type_statedump(session,
2816 &field->type, nesting);
2817 if (ret)
2818 return ret;
2819 return lttng_field_name_statedump(session, field, nesting);
2820 }
2821
2822 /*
2823 * Must be called with sessions_mutex held.
2824 */
2825 static
2826 int _lttng_array_field_statedump(struct lttng_session *session,
2827 const struct lttng_event_field *field,
2828 size_t nesting)
2829 {
2830 int ret;
2831 const struct lttng_type *elem_type;
2832
2833 WARN_ON_ONCE(field->type.atype != atype_array_nestable);
2834
2835 if (field->type.u.array_nestable.alignment) {
2836 ret = print_tabs(session, nesting);
2837 if (ret)
2838 return ret;
2839 ret = lttng_metadata_printf(session,
2840 "struct { } align(%u) _%s_padding;\n",
2841 field->type.u.array_nestable.alignment * CHAR_BIT,
2842 field->name);
2843 if (ret)
2844 return ret;
2845 }
2846 /*
2847 * Nested compound types: Only array of structures and variants are
2848 * currently supported.
2849 */
2850 elem_type = field->type.u.array_nestable.elem_type;
2851 switch (elem_type->atype) {
2852 case atype_integer:
2853 case atype_struct_nestable:
2854 case atype_variant_nestable:
2855 ret = _lttng_type_statedump(session, elem_type, nesting);
2856 if (ret)
2857 return ret;
2858 break;
2859
2860 default:
2861 return -EINVAL;
2862 }
2863 ret = lttng_metadata_printf(session,
2864 " _%s[%u];\n",
2865 field->name,
2866 field->type.u.array_nestable.length);
2867 return ret;
2868 }
2869
2870 /*
2871 * Must be called with sessions_mutex held.
2872 */
2873 static
2874 int _lttng_sequence_field_statedump(struct lttng_session *session,
2875 const struct lttng_event_field *field,
2876 size_t nesting)
2877 {
2878 int ret;
2879 const char *length_name;
2880 const struct lttng_type *elem_type;
2881
2882 WARN_ON_ONCE(field->type.atype != atype_sequence_nestable);
2883
2884 length_name = field->type.u.sequence_nestable.length_name;
2885
2886 if (field->type.u.sequence_nestable.alignment) {
2887 ret = print_tabs(session, nesting);
2888 if (ret)
2889 return ret;
2890 ret = lttng_metadata_printf(session,
2891 "struct { } align(%u) _%s_padding;\n",
2892 field->type.u.sequence_nestable.alignment * CHAR_BIT,
2893 field->name);
2894 if (ret)
2895 return ret;
2896 }
2897
2898 /*
2899 * Nested compound types: Only array of structures and variants are
2900 * currently supported.
2901 */
2902 elem_type = field->type.u.sequence_nestable.elem_type;
2903 switch (elem_type->atype) {
2904 case atype_integer:
2905 case atype_struct_nestable:
2906 case atype_variant_nestable:
2907 ret = _lttng_type_statedump(session, elem_type, nesting);
2908 if (ret)
2909 return ret;
2910 break;
2911
2912 default:
2913 return -EINVAL;
2914 }
2915 ret = lttng_metadata_printf(session,
2916 " _%s[ _%s ];\n",
2917 field->name,
2918 field->type.u.sequence_nestable.length_name);
2919 return ret;
2920 }
2921
2922 /*
2923 * Must be called with sessions_mutex held.
2924 */
2925 static
2926 int _lttng_enum_type_statedump(struct lttng_session *session,
2927 const struct lttng_type *type,
2928 size_t nesting)
2929 {
2930 const struct lttng_enum_desc *enum_desc;
2931 const struct lttng_type *container_type;
2932 int ret;
2933 unsigned int i, nr_entries;
2934
2935 container_type = type->u.enum_nestable.container_type;
2936 if (container_type->atype != atype_integer) {
2937 ret = -EINVAL;
2938 goto end;
2939 }
2940 enum_desc = type->u.enum_nestable.desc;
2941 nr_entries = enum_desc->nr_entries;
2942
2943 ret = print_tabs(session, nesting);
2944 if (ret)
2945 goto end;
2946 ret = lttng_metadata_printf(session, "enum : ");
2947 if (ret)
2948 goto end;
2949 ret = _lttng_integer_type_statedump(session, container_type, 0);
2950 if (ret)
2951 goto end;
2952 ret = lttng_metadata_printf(session, " {\n");
2953 if (ret)
2954 goto end;
2955 /* Dump all entries */
2956 for (i = 0; i < nr_entries; i++) {
2957 const struct lttng_enum_entry *entry = &enum_desc->entries[i];
2958 int j, len;
2959
2960 ret = print_tabs(session, nesting + 1);
2961 if (ret)
2962 goto end;
2963 ret = lttng_metadata_printf(session,
2964 "\"");
2965 if (ret)
2966 goto end;
2967 len = strlen(entry->string);
2968 /* Escape the character '"' */
2969 for (j = 0; j < len; j++) {
2970 char c = entry->string[j];
2971
2972 switch (c) {
2973 case '"':
2974 ret = lttng_metadata_printf(session,
2975 "\\\"");
2976 break;
2977 case '\\':
2978 ret = lttng_metadata_printf(session,
2979 "\\\\");
2980 break;
2981 default:
2982 ret = lttng_metadata_printf(session,
2983 "%c", c);
2984 break;
2985 }
2986 if (ret)
2987 goto end;
2988 }
2989 ret = lttng_metadata_printf(session, "\"");
2990 if (ret)
2991 goto end;
2992
2993 if (entry->options.is_auto) {
2994 ret = lttng_metadata_printf(session, ",\n");
2995 if (ret)
2996 goto end;
2997 } else {
2998 ret = lttng_metadata_printf(session,
2999 " = ");
3000 if (ret)
3001 goto end;
3002 if (entry->start.signedness)
3003 ret = lttng_metadata_printf(session,
3004 "%lld", (long long) entry->start.value);
3005 else
3006 ret = lttng_metadata_printf(session,
3007 "%llu", entry->start.value);
3008 if (ret)
3009 goto end;
3010 if (entry->start.signedness == entry->end.signedness &&
3011 entry->start.value
3012 == entry->end.value) {
3013 ret = lttng_metadata_printf(session,
3014 ",\n");
3015 } else {
3016 if (entry->end.signedness) {
3017 ret = lttng_metadata_printf(session,
3018 " ... %lld,\n",
3019 (long long) entry->end.value);
3020 } else {
3021 ret = lttng_metadata_printf(session,
3022 " ... %llu,\n",
3023 entry->end.value);
3024 }
3025 }
3026 if (ret)
3027 goto end;
3028 }
3029 }
3030 ret = print_tabs(session, nesting);
3031 if (ret)
3032 goto end;
3033 ret = lttng_metadata_printf(session, "}");
3034 end:
3035 return ret;
3036 }
3037
3038 /*
3039 * Must be called with sessions_mutex held.
3040 */
3041 static
3042 int _lttng_enum_field_statedump(struct lttng_session *session,
3043 const struct lttng_event_field *field,
3044 size_t nesting)
3045 {
3046 int ret;
3047
3048 ret = _lttng_enum_type_statedump(session, &field->type, nesting);
3049 if (ret)
3050 return ret;
3051 return lttng_field_name_statedump(session, field, nesting);
3052 }
3053
3054 static
3055 int _lttng_integer_field_statedump(struct lttng_session *session,
3056 const struct lttng_event_field *field,
3057 size_t nesting)
3058 {
3059 int ret;
3060
3061 ret = _lttng_integer_type_statedump(session, &field->type, nesting);
3062 if (ret)
3063 return ret;
3064 return lttng_field_name_statedump(session, field, nesting);
3065 }
3066
3067 static
3068 int _lttng_string_type_statedump(struct lttng_session *session,
3069 const struct lttng_type *type,
3070 size_t nesting)
3071 {
3072 int ret;
3073
3074 WARN_ON_ONCE(type->atype != atype_string);
3075 /* Default encoding is UTF8 */
3076 ret = print_tabs(session, nesting);
3077 if (ret)
3078 return ret;
3079 ret = lttng_metadata_printf(session,
3080 "string%s",
3081 type->u.string.encoding == lttng_encode_ASCII ?
3082 " { encoding = ASCII; }" : "");
3083 return ret;
3084 }
3085
3086 static
3087 int _lttng_string_field_statedump(struct lttng_session *session,
3088 const struct lttng_event_field *field,
3089 size_t nesting)
3090 {
3091 int ret;
3092
3093 WARN_ON_ONCE(field->type.atype != atype_string);
3094 ret = _lttng_string_type_statedump(session, &field->type, nesting);
3095 if (ret)
3096 return ret;
3097 return lttng_field_name_statedump(session, field, nesting);
3098 }
3099
3100 /*
3101 * Must be called with sessions_mutex held.
3102 */
3103 static
3104 int _lttng_type_statedump(struct lttng_session *session,
3105 const struct lttng_type *type,
3106 size_t nesting)
3107 {
3108 int ret = 0;
3109
3110 switch (type->atype) {
3111 case atype_integer:
3112 ret = _lttng_integer_type_statedump(session, type, nesting);
3113 break;
3114 case atype_enum_nestable:
3115 ret = _lttng_enum_type_statedump(session, type, nesting);
3116 break;
3117 case atype_string:
3118 ret = _lttng_string_type_statedump(session, type, nesting);
3119 break;
3120 case atype_struct_nestable:
3121 ret = _lttng_struct_type_statedump(session, type, nesting);
3122 break;
3123 case atype_variant_nestable:
3124 ret = _lttng_variant_type_statedump(session, type, nesting);
3125 break;
3126
3127 /* Nested arrays and sequences are not supported yet. */
3128 case atype_array_nestable:
3129 case atype_sequence_nestable:
3130 default:
3131 WARN_ON_ONCE(1);
3132 return -EINVAL;
3133 }
3134 return ret;
3135 }
3136
3137 /*
3138 * Must be called with sessions_mutex held.
3139 */
3140 static
3141 int _lttng_field_statedump(struct lttng_session *session,
3142 const struct lttng_event_field *field,
3143 size_t nesting)
3144 {
3145 int ret = 0;
3146
3147 switch (field->type.atype) {
3148 case atype_integer:
3149 ret = _lttng_integer_field_statedump(session, field, nesting);
3150 break;
3151 case atype_enum_nestable:
3152 ret = _lttng_enum_field_statedump(session, field, nesting);
3153 break;
3154 case atype_string:
3155 ret = _lttng_string_field_statedump(session, field, nesting);
3156 break;
3157 case atype_struct_nestable:
3158 ret = _lttng_struct_field_statedump(session, field, nesting);
3159 break;
3160 case atype_array_nestable:
3161 ret = _lttng_array_field_statedump(session, field, nesting);
3162 break;
3163 case atype_sequence_nestable:
3164 ret = _lttng_sequence_field_statedump(session, field, nesting);
3165 break;
3166 case atype_variant_nestable:
3167 ret = _lttng_variant_field_statedump(session, field, nesting);
3168 break;
3169
3170 default:
3171 WARN_ON_ONCE(1);
3172 return -EINVAL;
3173 }
3174 return ret;
3175 }
3176
3177 static
3178 int _lttng_context_metadata_statedump(struct lttng_session *session,
3179 struct lttng_ctx *ctx)
3180 {
3181 int ret = 0;
3182 int i;
3183
3184 if (!ctx)
3185 return 0;
3186 for (i = 0; i < ctx->nr_fields; i++) {
3187 const struct lttng_ctx_field *field = &ctx->fields[i];
3188
3189 ret = _lttng_field_statedump(session, &field->event_field, 2);
3190 if (ret)
3191 return ret;
3192 }
3193 return ret;
3194 }
3195
3196 static
3197 int _lttng_fields_metadata_statedump(struct lttng_session *session,
3198 struct lttng_event *event)
3199 {
3200 const struct lttng_event_desc *desc = event->desc;
3201 int ret = 0;
3202 int i;
3203
3204 for (i = 0; i < desc->nr_fields; i++) {
3205 const struct lttng_event_field *field = &desc->fields[i];
3206
3207 ret = _lttng_field_statedump(session, field, 2);
3208 if (ret)
3209 return ret;
3210 }
3211 return ret;
3212 }
3213
3214 /*
3215 * Must be called with sessions_mutex held.
3216 * The entire event metadata is printed as a single atomic metadata
3217 * transaction.
3218 */
3219 static
3220 int _lttng_event_metadata_statedump(struct lttng_session *session,
3221 struct lttng_channel *chan,
3222 struct lttng_event *event)
3223 {
3224 int ret = 0;
3225
3226 if (event->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3227 return 0;
3228 if (chan->channel_type == METADATA_CHANNEL)
3229 return 0;
3230
3231 lttng_metadata_begin(session);
3232
3233 ret = lttng_metadata_printf(session,
3234 "event {\n"
3235 " name = \"%s\";\n"
3236 " id = %u;\n"
3237 " stream_id = %u;\n",
3238 event->desc->name,
3239 event->id,
3240 event->chan->id);
3241 if (ret)
3242 goto end;
3243
3244 if (event->ctx) {
3245 ret = lttng_metadata_printf(session,
3246 " context := struct {\n");
3247 if (ret)
3248 goto end;
3249 }
3250 ret = _lttng_context_metadata_statedump(session, event->ctx);
3251 if (ret)
3252 goto end;
3253 if (event->ctx) {
3254 ret = lttng_metadata_printf(session,
3255 " };\n");
3256 if (ret)
3257 goto end;
3258 }
3259
3260 ret = lttng_metadata_printf(session,
3261 " fields := struct {\n"
3262 );
3263 if (ret)
3264 goto end;
3265
3266 ret = _lttng_fields_metadata_statedump(session, event);
3267 if (ret)
3268 goto end;
3269
3270 /*
3271 * LTTng space reservation can only reserve multiples of the
3272 * byte size.
3273 */
3274 ret = lttng_metadata_printf(session,
3275 " };\n"
3276 "};\n\n");
3277 if (ret)
3278 goto end;
3279
3280 event->metadata_dumped = 1;
3281 end:
3282 lttng_metadata_end(session);
3283 return ret;
3284
3285 }
3286
3287 /*
3288 * Must be called with sessions_mutex held.
3289 * The entire channel metadata is printed as a single atomic metadata
3290 * transaction.
3291 */
3292 static
3293 int _lttng_channel_metadata_statedump(struct lttng_session *session,
3294 struct lttng_channel *chan)
3295 {
3296 int ret = 0;
3297
3298 if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3299 return 0;
3300
3301 if (chan->channel_type == METADATA_CHANNEL)
3302 return 0;
3303
3304 lttng_metadata_begin(session);
3305
3306 WARN_ON_ONCE(!chan->header_type);
3307 ret = lttng_metadata_printf(session,
3308 "stream {\n"
3309 " id = %u;\n"
3310 " event.header := %s;\n"
3311 " packet.context := struct packet_context;\n",
3312 chan->id,
3313 chan->header_type == 1 ? "struct event_header_compact" :
3314 "struct event_header_large");
3315 if (ret)
3316 goto end;
3317
3318 if (chan->ctx) {
3319 ret = lttng_metadata_printf(session,
3320 " event.context := struct {\n");
3321 if (ret)
3322 goto end;
3323 }
3324 ret = _lttng_context_metadata_statedump(session, chan->ctx);
3325 if (ret)
3326 goto end;
3327 if (chan->ctx) {
3328 ret = lttng_metadata_printf(session,
3329 " };\n");
3330 if (ret)
3331 goto end;
3332 }
3333
3334 ret = lttng_metadata_printf(session,
3335 "};\n\n");
3336
3337 chan->metadata_dumped = 1;
3338 end:
3339 lttng_metadata_end(session);
3340 return ret;
3341 }
3342
3343 /*
3344 * Must be called with sessions_mutex held.
3345 */
3346 static
3347 int _lttng_stream_packet_context_declare(struct lttng_session *session)
3348 {
3349 return lttng_metadata_printf(session,
3350 "struct packet_context {\n"
3351 " uint64_clock_monotonic_t timestamp_begin;\n"
3352 " uint64_clock_monotonic_t timestamp_end;\n"
3353 " uint64_t content_size;\n"
3354 " uint64_t packet_size;\n"
3355 " uint64_t packet_seq_num;\n"
3356 " unsigned long events_discarded;\n"
3357 " uint32_t cpu_id;\n"
3358 "};\n\n"
3359 );
3360 }
3361
3362 /*
3363 * Compact header:
3364 * id: range: 0 - 30.
3365 * id 31 is reserved to indicate an extended header.
3366 *
3367 * Large header:
3368 * id: range: 0 - 65534.
3369 * id 65535 is reserved to indicate an extended header.
3370 *
3371 * Must be called with sessions_mutex held.
3372 */
3373 static
3374 int _lttng_event_header_declare(struct lttng_session *session)
3375 {
3376 return lttng_metadata_printf(session,
3377 "struct event_header_compact {\n"
3378 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3379 " variant <id> {\n"
3380 " struct {\n"
3381 " uint27_clock_monotonic_t timestamp;\n"
3382 " } compact;\n"
3383 " struct {\n"
3384 " uint32_t id;\n"
3385 " uint64_clock_monotonic_t timestamp;\n"
3386 " } extended;\n"
3387 " } v;\n"
3388 "} align(%u);\n"
3389 "\n"
3390 "struct event_header_large {\n"
3391 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3392 " variant <id> {\n"
3393 " struct {\n"
3394 " uint32_clock_monotonic_t timestamp;\n"
3395 " } compact;\n"
3396 " struct {\n"
3397 " uint32_t id;\n"
3398 " uint64_clock_monotonic_t timestamp;\n"
3399 " } extended;\n"
3400 " } v;\n"
3401 "} align(%u);\n\n",
3402 lttng_alignof(uint32_t) * CHAR_BIT,
3403 lttng_alignof(uint16_t) * CHAR_BIT
3404 );
3405 }
3406
3407 /*
3408 * Approximation of NTP time of day to clock monotonic correlation,
3409 * taken at start of trace.
3410 * Yes, this is only an approximation. Yes, we can (and will) do better
3411 * in future versions.
3412 * This function may return a negative offset. It may happen if the
3413 * system sets the REALTIME clock to 0 after boot.
3414 *
3415 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3416 * y2038 compliant.
3417 */
3418 static
3419 int64_t measure_clock_offset(void)
3420 {
3421 uint64_t monotonic_avg, monotonic[2], realtime;
3422 uint64_t tcf = trace_clock_freq();
3423 int64_t offset;
3424 unsigned long flags;
3425 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3426 struct timespec64 rts = { 0, 0 };
3427 #else
3428 struct timespec rts = { 0, 0 };
3429 #endif
3430
3431 /* Disable interrupts to increase correlation precision. */
3432 local_irq_save(flags);
3433 monotonic[0] = trace_clock_read64();
3434 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3435 ktime_get_real_ts64(&rts);
3436 #else
3437 getnstimeofday(&rts);
3438 #endif
3439 monotonic[1] = trace_clock_read64();
3440 local_irq_restore(flags);
3441
3442 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3443 realtime = (uint64_t) rts.tv_sec * tcf;
3444 if (tcf == NSEC_PER_SEC) {
3445 realtime += rts.tv_nsec;
3446 } else {
3447 uint64_t n = rts.tv_nsec * tcf;
3448
3449 do_div(n, NSEC_PER_SEC);
3450 realtime += n;
3451 }
3452 offset = (int64_t) realtime - monotonic_avg;
3453 return offset;
3454 }
3455
3456 static
3457 int print_escaped_ctf_string(struct lttng_session *session, const char *string)
3458 {
3459 int ret = 0;
3460 size_t i;
3461 char cur;
3462
3463 i = 0;
3464 cur = string[i];
3465 while (cur != '\0') {
3466 switch (cur) {
3467 case '\n':
3468 ret = lttng_metadata_printf(session, "%s", "\\n");
3469 break;
3470 case '\\':
3471 case '"':
3472 ret = lttng_metadata_printf(session, "%c", '\\');
3473 if (ret)
3474 goto error;
3475 /* We still print the current char */
3476 /* Fallthrough */
3477 default:
3478 ret = lttng_metadata_printf(session, "%c", cur);
3479 break;
3480 }
3481
3482 if (ret)
3483 goto error;
3484
3485 cur = string[++i];
3486 }
3487 error:
3488 return ret;
3489 }
3490
3491 static
3492 int print_metadata_escaped_field(struct lttng_session *session, const char *field,
3493 const char *field_value)
3494 {
3495 int ret;
3496
3497 ret = lttng_metadata_printf(session, " %s = \"", field);
3498 if (ret)
3499 goto error;
3500
3501 ret = print_escaped_ctf_string(session, field_value);
3502 if (ret)
3503 goto error;
3504
3505 ret = lttng_metadata_printf(session, "\";\n");
3506
3507 error:
3508 return ret;
3509 }
3510
3511 /*
3512 * Output metadata into this session's metadata buffers.
3513 * Must be called with sessions_mutex held.
3514 */
3515 static
3516 int _lttng_session_metadata_statedump(struct lttng_session *session)
3517 {
3518 unsigned char *uuid_c = session->uuid.b;
3519 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3520 const char *product_uuid;
3521 struct lttng_channel *chan;
3522 struct lttng_event *event;
3523 int ret = 0;
3524
3525 if (!LTTNG_READ_ONCE(session->active))
3526 return 0;
3527
3528 lttng_metadata_begin(session);
3529
3530 if (session->metadata_dumped)
3531 goto skip_session;
3532
3533 snprintf(uuid_s, sizeof(uuid_s),
3534 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3535 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3536 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3537 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3538 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3539
3540 ret = lttng_metadata_printf(session,
3541 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3542 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3543 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3544 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3545 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3546 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3547 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3548 "\n"
3549 "trace {\n"
3550 " major = %u;\n"
3551 " minor = %u;\n"
3552 " uuid = \"%s\";\n"
3553 " byte_order = %s;\n"
3554 " packet.header := struct {\n"
3555 " uint32_t magic;\n"
3556 " uint8_t uuid[16];\n"
3557 " uint32_t stream_id;\n"
3558 " uint64_t stream_instance_id;\n"
3559 " };\n"
3560 "};\n\n",
3561 lttng_alignof(uint8_t) * CHAR_BIT,
3562 lttng_alignof(uint16_t) * CHAR_BIT,
3563 lttng_alignof(uint32_t) * CHAR_BIT,
3564 lttng_alignof(uint64_t) * CHAR_BIT,
3565 sizeof(unsigned long) * CHAR_BIT,
3566 lttng_alignof(unsigned long) * CHAR_BIT,
3567 CTF_SPEC_MAJOR,
3568 CTF_SPEC_MINOR,
3569 uuid_s,
3570 #if __BYTE_ORDER == __BIG_ENDIAN
3571 "be"
3572 #else
3573 "le"
3574 #endif
3575 );
3576 if (ret)
3577 goto end;
3578
3579 ret = lttng_metadata_printf(session,
3580 "env {\n"
3581 " hostname = \"%s\";\n"
3582 " domain = \"kernel\";\n"
3583 " sysname = \"%s\";\n"
3584 " kernel_release = \"%s\";\n"
3585 " kernel_version = \"%s\";\n"
3586 " tracer_name = \"lttng-modules\";\n"
3587 " tracer_major = %d;\n"
3588 " tracer_minor = %d;\n"
3589 " tracer_patchlevel = %d;\n"
3590 " trace_buffering_scheme = \"global\";\n",
3591 current->nsproxy->uts_ns->name.nodename,
3592 utsname()->sysname,
3593 utsname()->release,
3594 utsname()->version,
3595 LTTNG_MODULES_MAJOR_VERSION,
3596 LTTNG_MODULES_MINOR_VERSION,
3597 LTTNG_MODULES_PATCHLEVEL_VERSION
3598 );
3599 if (ret)
3600 goto end;
3601
3602 ret = print_metadata_escaped_field(session, "trace_name", session->name);
3603 if (ret)
3604 goto end;
3605 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3606 session->creation_time);
3607 if (ret)
3608 goto end;
3609
3610 /* Add the product UUID to the 'env' section */
3611 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3612 if (product_uuid) {
3613 ret = lttng_metadata_printf(session,
3614 " product_uuid = \"%s\";\n",
3615 product_uuid
3616 );
3617 if (ret)
3618 goto end;
3619 }
3620
3621 /* Close the 'env' section */
3622 ret = lttng_metadata_printf(session, "};\n\n");
3623 if (ret)
3624 goto end;
3625
3626 ret = lttng_metadata_printf(session,
3627 "clock {\n"
3628 " name = \"%s\";\n",
3629 trace_clock_name()
3630 );
3631 if (ret)
3632 goto end;
3633
3634 if (!trace_clock_uuid(clock_uuid_s)) {
3635 ret = lttng_metadata_printf(session,
3636 " uuid = \"%s\";\n",
3637 clock_uuid_s
3638 );
3639 if (ret)
3640 goto end;
3641 }
3642
3643 ret = lttng_metadata_printf(session,
3644 " description = \"%s\";\n"
3645 " freq = %llu; /* Frequency, in Hz */\n"
3646 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
3647 " offset = %lld;\n"
3648 "};\n\n",
3649 trace_clock_description(),
3650 (unsigned long long) trace_clock_freq(),
3651 (long long) measure_clock_offset()
3652 );
3653 if (ret)
3654 goto end;
3655
3656 ret = lttng_metadata_printf(session,
3657 "typealias integer {\n"
3658 " size = 27; align = 1; signed = false;\n"
3659 " map = clock.%s.value;\n"
3660 "} := uint27_clock_monotonic_t;\n"
3661 "\n"
3662 "typealias integer {\n"
3663 " size = 32; align = %u; signed = false;\n"
3664 " map = clock.%s.value;\n"
3665 "} := uint32_clock_monotonic_t;\n"
3666 "\n"
3667 "typealias integer {\n"
3668 " size = 64; align = %u; signed = false;\n"
3669 " map = clock.%s.value;\n"
3670 "} := uint64_clock_monotonic_t;\n\n",
3671 trace_clock_name(),
3672 lttng_alignof(uint32_t) * CHAR_BIT,
3673 trace_clock_name(),
3674 lttng_alignof(uint64_t) * CHAR_BIT,
3675 trace_clock_name()
3676 );
3677 if (ret)
3678 goto end;
3679
3680 ret = _lttng_stream_packet_context_declare(session);
3681 if (ret)
3682 goto end;
3683
3684 ret = _lttng_event_header_declare(session);
3685 if (ret)
3686 goto end;
3687
3688 skip_session:
3689 list_for_each_entry(chan, &session->chan, list) {
3690 ret = _lttng_channel_metadata_statedump(session, chan);
3691 if (ret)
3692 goto end;
3693 }
3694
3695 list_for_each_entry(event, &session->events, list) {
3696 ret = _lttng_event_metadata_statedump(session, event->chan, event);
3697 if (ret)
3698 goto end;
3699 }
3700 session->metadata_dumped = 1;
3701 end:
3702 lttng_metadata_end(session);
3703 return ret;
3704 }
3705
3706 /**
3707 * lttng_transport_register - LTT transport registration
3708 * @transport: transport structure
3709 *
3710 * Registers a transport which can be used as output to extract the data out of
3711 * LTTng. The module calling this registration function must ensure that no
3712 * trap-inducing code will be executed by the transport functions. E.g.
3713 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
3714 * is made visible to the transport function. This registration acts as a
3715 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
3716 * after its registration must it synchronize the TLBs.
3717 */
3718 void lttng_transport_register(struct lttng_transport *transport)
3719 {
3720 /*
3721 * Make sure no page fault can be triggered by the module about to be
3722 * registered. We deal with this here so we don't have to call
3723 * vmalloc_sync_mappings() in each module's init.
3724 */
3725 wrapper_vmalloc_sync_mappings();
3726
3727 mutex_lock(&sessions_mutex);
3728 list_add_tail(&transport->node, &lttng_transport_list);
3729 mutex_unlock(&sessions_mutex);
3730 }
3731 EXPORT_SYMBOL_GPL(lttng_transport_register);
3732
3733 /**
3734 * lttng_transport_unregister - LTT transport unregistration
3735 * @transport: transport structure
3736 */
3737 void lttng_transport_unregister(struct lttng_transport *transport)
3738 {
3739 mutex_lock(&sessions_mutex);
3740 list_del(&transport->node);
3741 mutex_unlock(&sessions_mutex);
3742 }
3743 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
3744
3745 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
3746
3747 enum cpuhp_state lttng_hp_prepare;
3748 enum cpuhp_state lttng_hp_online;
3749
3750 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
3751 {
3752 struct lttng_cpuhp_node *lttng_node;
3753
3754 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
3755 switch (lttng_node->component) {
3756 case LTTNG_RING_BUFFER_FRONTEND:
3757 return 0;
3758 case LTTNG_RING_BUFFER_BACKEND:
3759 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
3760 case LTTNG_RING_BUFFER_ITER:
3761 return 0;
3762 case LTTNG_CONTEXT_PERF_COUNTERS:
3763 return 0;
3764 default:
3765 return -EINVAL;
3766 }
3767 }
3768
3769 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
3770 {
3771 struct lttng_cpuhp_node *lttng_node;
3772
3773 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
3774 switch (lttng_node->component) {
3775 case LTTNG_RING_BUFFER_FRONTEND:
3776 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
3777 case LTTNG_RING_BUFFER_BACKEND:
3778 return 0;
3779 case LTTNG_RING_BUFFER_ITER:
3780 return 0;
3781 case LTTNG_CONTEXT_PERF_COUNTERS:
3782 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
3783 default:
3784 return -EINVAL;
3785 }
3786 }
3787
3788 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
3789 {
3790 struct lttng_cpuhp_node *lttng_node;
3791
3792 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
3793 switch (lttng_node->component) {
3794 case LTTNG_RING_BUFFER_FRONTEND:
3795 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
3796 case LTTNG_RING_BUFFER_BACKEND:
3797 return 0;
3798 case LTTNG_RING_BUFFER_ITER:
3799 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
3800 case LTTNG_CONTEXT_PERF_COUNTERS:
3801 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
3802 default:
3803 return -EINVAL;
3804 }
3805 }
3806
3807 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
3808 {
3809 struct lttng_cpuhp_node *lttng_node;
3810
3811 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
3812 switch (lttng_node->component) {
3813 case LTTNG_RING_BUFFER_FRONTEND:
3814 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
3815 case LTTNG_RING_BUFFER_BACKEND:
3816 return 0;
3817 case LTTNG_RING_BUFFER_ITER:
3818 return 0;
3819 case LTTNG_CONTEXT_PERF_COUNTERS:
3820 return 0;
3821 default:
3822 return -EINVAL;
3823 }
3824 }
3825
3826 static int __init lttng_init_cpu_hotplug(void)
3827 {
3828 int ret;
3829
3830 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
3831 lttng_hotplug_prepare,
3832 lttng_hotplug_dead);
3833 if (ret < 0) {
3834 return ret;
3835 }
3836 lttng_hp_prepare = ret;
3837 lttng_rb_set_hp_prepare(ret);
3838
3839 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
3840 lttng_hotplug_online,
3841 lttng_hotplug_offline);
3842 if (ret < 0) {
3843 cpuhp_remove_multi_state(lttng_hp_prepare);
3844 lttng_hp_prepare = 0;
3845 return ret;
3846 }
3847 lttng_hp_online = ret;
3848 lttng_rb_set_hp_online(ret);
3849
3850 return 0;
3851 }
3852
3853 static void __exit lttng_exit_cpu_hotplug(void)
3854 {
3855 lttng_rb_set_hp_online(0);
3856 cpuhp_remove_multi_state(lttng_hp_online);
3857 lttng_rb_set_hp_prepare(0);
3858 cpuhp_remove_multi_state(lttng_hp_prepare);
3859 }
3860
3861 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
3862 static int lttng_init_cpu_hotplug(void)
3863 {
3864 return 0;
3865 }
3866 static void lttng_exit_cpu_hotplug(void)
3867 {
3868 }
3869 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
3870
3871
3872 static int __init lttng_events_init(void)
3873 {
3874 int ret;
3875
3876 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
3877 if (ret)
3878 return ret;
3879 ret = wrapper_get_pfnblock_flags_mask_init();
3880 if (ret)
3881 return ret;
3882 ret = wrapper_get_pageblock_flags_mask_init();
3883 if (ret)
3884 return ret;
3885 ret = lttng_probes_init();
3886 if (ret)
3887 return ret;
3888 ret = lttng_context_init();
3889 if (ret)
3890 return ret;
3891 ret = lttng_tracepoint_init();
3892 if (ret)
3893 goto error_tp;
3894 event_cache = KMEM_CACHE(lttng_event, 0);
3895 if (!event_cache) {
3896 ret = -ENOMEM;
3897 goto error_kmem_event;
3898 }
3899 event_notifier_cache = KMEM_CACHE(lttng_event_notifier, 0);
3900 if (!event_notifier_cache) {
3901 ret = -ENOMEM;
3902 goto error_kmem_event_notifier;
3903 }
3904 ret = lttng_abi_init();
3905 if (ret)
3906 goto error_abi;
3907 ret = lttng_logger_init();
3908 if (ret)
3909 goto error_logger;
3910 ret = lttng_init_cpu_hotplug();
3911 if (ret)
3912 goto error_hotplug;
3913 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
3914 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3915 __stringify(LTTNG_MODULES_MINOR_VERSION),
3916 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3917 LTTNG_MODULES_EXTRAVERSION,
3918 LTTNG_VERSION_NAME,
3919 #ifdef LTTNG_EXTRA_VERSION_GIT
3920 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3921 #else
3922 "",
3923 #endif
3924 #ifdef LTTNG_EXTRA_VERSION_NAME
3925 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3926 #else
3927 "");
3928 #endif
3929 return 0;
3930
3931 error_hotplug:
3932 lttng_logger_exit();
3933 error_logger:
3934 lttng_abi_exit();
3935 error_abi:
3936 kmem_cache_destroy(event_notifier_cache);
3937 error_kmem_event_notifier:
3938 kmem_cache_destroy(event_cache);
3939 error_kmem_event:
3940 lttng_tracepoint_exit();
3941 error_tp:
3942 lttng_context_exit();
3943 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
3944 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3945 __stringify(LTTNG_MODULES_MINOR_VERSION),
3946 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3947 LTTNG_MODULES_EXTRAVERSION,
3948 LTTNG_VERSION_NAME,
3949 #ifdef LTTNG_EXTRA_VERSION_GIT
3950 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3951 #else
3952 "",
3953 #endif
3954 #ifdef LTTNG_EXTRA_VERSION_NAME
3955 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3956 #else
3957 "");
3958 #endif
3959 return ret;
3960 }
3961
3962 module_init(lttng_events_init);
3963
3964 static void __exit lttng_events_exit(void)
3965 {
3966 struct lttng_session *session, *tmpsession;
3967
3968 lttng_exit_cpu_hotplug();
3969 lttng_logger_exit();
3970 lttng_abi_exit();
3971 list_for_each_entry_safe(session, tmpsession, &sessions, list)
3972 lttng_session_destroy(session);
3973 kmem_cache_destroy(event_cache);
3974 kmem_cache_destroy(event_notifier_cache);
3975 lttng_tracepoint_exit();
3976 lttng_context_exit();
3977 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
3978 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3979 __stringify(LTTNG_MODULES_MINOR_VERSION),
3980 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3981 LTTNG_MODULES_EXTRAVERSION,
3982 LTTNG_VERSION_NAME,
3983 #ifdef LTTNG_EXTRA_VERSION_GIT
3984 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3985 #else
3986 "",
3987 #endif
3988 #ifdef LTTNG_EXTRA_VERSION_NAME
3989 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3990 #else
3991 "");
3992 #endif
3993 }
3994
3995 module_exit(lttng_events_exit);
3996
3997 #include <generated/patches.h>
3998 #ifdef LTTNG_EXTRA_VERSION_GIT
3999 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4000 #endif
4001 #ifdef LTTNG_EXTRA_VERSION_NAME
4002 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4003 #endif
4004 MODULE_LICENSE("GPL and additional rights");
4005 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4006 MODULE_DESCRIPTION("LTTng tracer");
4007 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4008 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4009 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4010 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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