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