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