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[lttng-modules.git] / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
2 *
3 * lttng-events.c
4 *
5 * Holds LTTng per-session event registry.
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10 /*
11 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
12 * overrides a function with a define.
13 */
14 #include "wrapper/page_alloc.h"
15
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/jiffies.h>
21 #include <linux/utsname.h>
22 #include <linux/err.h>
23 #include <linux/seq_file.h>
24 #include <linux/file.h>
25 #include <linux/anon_inodes.h>
26 #include <wrapper/file.h>
27 #include <linux/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 <wrapper/ringbuffer/backend.h>
45 #include <wrapper/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_enablers(struct lttng_session *session);
59 static void lttng_session_sync_enablers(struct lttng_session *session);
60 static void lttng_enabler_destroy(struct lttng_enabler *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_field_statedump(struct lttng_session *session,
75 const struct lttng_event_field *field,
76 size_t nesting);
77
78 void synchronize_trace(void)
79 {
80 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0))
81 synchronize_rcu();
82 #else
83 synchronize_sched();
84 #endif
85
86 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
87 #ifdef CONFIG_PREEMPT_RT_FULL
88 synchronize_rcu();
89 #endif
90 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
91 #ifdef CONFIG_PREEMPT_RT
92 synchronize_rcu();
93 #endif
94 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
95 }
96
97 void lttng_lock_sessions(void)
98 {
99 mutex_lock(&sessions_mutex);
100 }
101
102 void lttng_unlock_sessions(void)
103 {
104 mutex_unlock(&sessions_mutex);
105 }
106
107 /*
108 * Called with sessions lock held.
109 */
110 int lttng_session_active(void)
111 {
112 struct lttng_session *iter;
113
114 list_for_each_entry(iter, &sessions, list) {
115 if (iter->active)
116 return 1;
117 }
118 return 0;
119 }
120
121 struct lttng_session *lttng_session_create(void)
122 {
123 struct lttng_session *session;
124 struct lttng_metadata_cache *metadata_cache;
125 int i;
126
127 mutex_lock(&sessions_mutex);
128 session = lttng_kvzalloc(sizeof(struct lttng_session), GFP_KERNEL);
129 if (!session)
130 goto err;
131 INIT_LIST_HEAD(&session->chan);
132 INIT_LIST_HEAD(&session->events);
133 lttng_guid_gen(&session->uuid);
134
135 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
136 GFP_KERNEL);
137 if (!metadata_cache)
138 goto err_free_session;
139 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
140 if (!metadata_cache->data)
141 goto err_free_cache;
142 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
143 kref_init(&metadata_cache->refcount);
144 mutex_init(&metadata_cache->lock);
145 session->metadata_cache = metadata_cache;
146 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
147 memcpy(&metadata_cache->uuid, &session->uuid,
148 sizeof(metadata_cache->uuid));
149 INIT_LIST_HEAD(&session->enablers_head);
150 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
151 INIT_HLIST_HEAD(&session->events_ht.table[i]);
152 list_add(&session->list, &sessions);
153 session->pid_tracker.session = session;
154 session->pid_tracker.tracker_type = TRACKER_PID;
155 session->vpid_tracker.session = session;
156 session->vpid_tracker.tracker_type = TRACKER_VPID;
157 session->uid_tracker.session = session;
158 session->uid_tracker.tracker_type = TRACKER_UID;
159 session->vuid_tracker.session = session;
160 session->vuid_tracker.tracker_type = TRACKER_VUID;
161 session->gid_tracker.session = session;
162 session->gid_tracker.tracker_type = TRACKER_GID;
163 session->vgid_tracker.session = session;
164 session->vgid_tracker.tracker_type = TRACKER_VGID;
165 mutex_unlock(&sessions_mutex);
166 return session;
167
168 err_free_cache:
169 kfree(metadata_cache);
170 err_free_session:
171 lttng_kvfree(session);
172 err:
173 mutex_unlock(&sessions_mutex);
174 return NULL;
175 }
176
177 void metadata_cache_destroy(struct kref *kref)
178 {
179 struct lttng_metadata_cache *cache =
180 container_of(kref, struct lttng_metadata_cache, refcount);
181 vfree(cache->data);
182 kfree(cache);
183 }
184
185 void lttng_session_destroy(struct lttng_session *session)
186 {
187 struct lttng_channel *chan, *tmpchan;
188 struct lttng_event *event, *tmpevent;
189 struct lttng_metadata_stream *metadata_stream;
190 struct lttng_enabler *enabler, *tmpenabler;
191 int ret;
192
193 mutex_lock(&sessions_mutex);
194 WRITE_ONCE(session->active, 0);
195 list_for_each_entry(chan, &session->chan, list) {
196 ret = lttng_syscalls_unregister(chan);
197 WARN_ON(ret);
198 }
199 list_for_each_entry(event, &session->events, list) {
200 ret = _lttng_event_unregister(event);
201 WARN_ON(ret);
202 }
203 synchronize_trace(); /* Wait for in-flight events to complete */
204 list_for_each_entry(chan, &session->chan, list) {
205 ret = lttng_syscalls_destroy(chan);
206 WARN_ON(ret);
207 }
208 list_for_each_entry_safe(enabler, tmpenabler,
209 &session->enablers_head, node)
210 lttng_enabler_destroy(enabler);
211 list_for_each_entry_safe(event, tmpevent, &session->events, list)
212 _lttng_event_destroy(event);
213 list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
214 BUG_ON(chan->channel_type == METADATA_CHANNEL);
215 _lttng_channel_destroy(chan);
216 }
217 mutex_lock(&session->metadata_cache->lock);
218 list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
219 _lttng_metadata_channel_hangup(metadata_stream);
220 mutex_unlock(&session->metadata_cache->lock);
221 lttng_id_tracker_destroy(&session->pid_tracker, false);
222 lttng_id_tracker_destroy(&session->vpid_tracker, false);
223 lttng_id_tracker_destroy(&session->uid_tracker, false);
224 lttng_id_tracker_destroy(&session->vuid_tracker, false);
225 lttng_id_tracker_destroy(&session->gid_tracker, false);
226 lttng_id_tracker_destroy(&session->vgid_tracker, false);
227 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
228 list_del(&session->list);
229 mutex_unlock(&sessions_mutex);
230 lttng_kvfree(session);
231 }
232
233 int lttng_session_statedump(struct lttng_session *session)
234 {
235 int ret;
236
237 mutex_lock(&sessions_mutex);
238 ret = lttng_statedump_start(session);
239 mutex_unlock(&sessions_mutex);
240 return ret;
241 }
242
243 int lttng_session_enable(struct lttng_session *session)
244 {
245 int ret = 0;
246 struct lttng_channel *chan;
247
248 mutex_lock(&sessions_mutex);
249 if (session->active) {
250 ret = -EBUSY;
251 goto end;
252 }
253
254 /* Set transient enabler state to "enabled" */
255 session->tstate = 1;
256
257 /* We need to sync enablers with session before activation. */
258 lttng_session_sync_enablers(session);
259
260 /*
261 * Snapshot the number of events per channel to know the type of header
262 * we need to use.
263 */
264 list_for_each_entry(chan, &session->chan, list) {
265 if (chan->header_type)
266 continue; /* don't change it if session stop/restart */
267 if (chan->free_event_id < 31)
268 chan->header_type = 1; /* compact */
269 else
270 chan->header_type = 2; /* large */
271 }
272
273 /* Clear each stream's quiescent state. */
274 list_for_each_entry(chan, &session->chan, list) {
275 if (chan->channel_type != METADATA_CHANNEL)
276 lib_ring_buffer_clear_quiescent_channel(chan->chan);
277 }
278
279 WRITE_ONCE(session->active, 1);
280 WRITE_ONCE(session->been_active, 1);
281 ret = _lttng_session_metadata_statedump(session);
282 if (ret) {
283 WRITE_ONCE(session->active, 0);
284 goto end;
285 }
286 ret = lttng_statedump_start(session);
287 if (ret)
288 WRITE_ONCE(session->active, 0);
289 end:
290 mutex_unlock(&sessions_mutex);
291 return ret;
292 }
293
294 int lttng_session_disable(struct lttng_session *session)
295 {
296 int ret = 0;
297 struct lttng_channel *chan;
298
299 mutex_lock(&sessions_mutex);
300 if (!session->active) {
301 ret = -EBUSY;
302 goto end;
303 }
304 WRITE_ONCE(session->active, 0);
305
306 /* Set transient enabler state to "disabled" */
307 session->tstate = 0;
308 lttng_session_sync_enablers(session);
309
310 /* Set each stream's quiescent state. */
311 list_for_each_entry(chan, &session->chan, list) {
312 if (chan->channel_type != METADATA_CHANNEL)
313 lib_ring_buffer_set_quiescent_channel(chan->chan);
314 }
315 end:
316 mutex_unlock(&sessions_mutex);
317 return ret;
318 }
319
320 int lttng_session_metadata_regenerate(struct lttng_session *session)
321 {
322 int ret = 0;
323 struct lttng_channel *chan;
324 struct lttng_event *event;
325 struct lttng_metadata_cache *cache = session->metadata_cache;
326 struct lttng_metadata_stream *stream;
327
328 mutex_lock(&sessions_mutex);
329 if (!session->active) {
330 ret = -EBUSY;
331 goto end;
332 }
333
334 mutex_lock(&cache->lock);
335 memset(cache->data, 0, cache->cache_alloc);
336 cache->metadata_written = 0;
337 cache->version++;
338 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list) {
339 stream->metadata_out = 0;
340 stream->metadata_in = 0;
341 }
342 mutex_unlock(&cache->lock);
343
344 session->metadata_dumped = 0;
345 list_for_each_entry(chan, &session->chan, list) {
346 chan->metadata_dumped = 0;
347 }
348
349 list_for_each_entry(event, &session->events, list) {
350 event->metadata_dumped = 0;
351 }
352
353 ret = _lttng_session_metadata_statedump(session);
354
355 end:
356 mutex_unlock(&sessions_mutex);
357 return ret;
358 }
359
360 int lttng_channel_enable(struct lttng_channel *channel)
361 {
362 int ret = 0;
363
364 mutex_lock(&sessions_mutex);
365 if (channel->channel_type == METADATA_CHANNEL) {
366 ret = -EPERM;
367 goto end;
368 }
369 if (channel->enabled) {
370 ret = -EEXIST;
371 goto end;
372 }
373 /* Set transient enabler state to "enabled" */
374 channel->tstate = 1;
375 lttng_session_sync_enablers(channel->session);
376 /* Set atomically the state to "enabled" */
377 WRITE_ONCE(channel->enabled, 1);
378 end:
379 mutex_unlock(&sessions_mutex);
380 return ret;
381 }
382
383 int lttng_channel_disable(struct lttng_channel *channel)
384 {
385 int ret = 0;
386
387 mutex_lock(&sessions_mutex);
388 if (channel->channel_type == METADATA_CHANNEL) {
389 ret = -EPERM;
390 goto end;
391 }
392 if (!channel->enabled) {
393 ret = -EEXIST;
394 goto end;
395 }
396 /* Set atomically the state to "disabled" */
397 WRITE_ONCE(channel->enabled, 0);
398 /* Set transient enabler state to "enabled" */
399 channel->tstate = 0;
400 lttng_session_sync_enablers(channel->session);
401 end:
402 mutex_unlock(&sessions_mutex);
403 return ret;
404 }
405
406 int lttng_event_enable(struct lttng_event *event)
407 {
408 int ret = 0;
409
410 mutex_lock(&sessions_mutex);
411 if (event->chan->channel_type == METADATA_CHANNEL) {
412 ret = -EPERM;
413 goto end;
414 }
415 if (event->enabled) {
416 ret = -EEXIST;
417 goto end;
418 }
419 switch (event->instrumentation) {
420 case LTTNG_KERNEL_TRACEPOINT:
421 case LTTNG_KERNEL_SYSCALL:
422 ret = -EINVAL;
423 break;
424 case LTTNG_KERNEL_KPROBE:
425 case LTTNG_KERNEL_UPROBE:
426 case LTTNG_KERNEL_NOOP:
427 WRITE_ONCE(event->enabled, 1);
428 break;
429 case LTTNG_KERNEL_KRETPROBE:
430 ret = lttng_kretprobes_event_enable_state(event, 1);
431 break;
432 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
433 default:
434 WARN_ON_ONCE(1);
435 ret = -EINVAL;
436 }
437 end:
438 mutex_unlock(&sessions_mutex);
439 return ret;
440 }
441
442 int lttng_event_disable(struct lttng_event *event)
443 {
444 int ret = 0;
445
446 mutex_lock(&sessions_mutex);
447 if (event->chan->channel_type == METADATA_CHANNEL) {
448 ret = -EPERM;
449 goto end;
450 }
451 if (!event->enabled) {
452 ret = -EEXIST;
453 goto end;
454 }
455 switch (event->instrumentation) {
456 case LTTNG_KERNEL_TRACEPOINT:
457 case LTTNG_KERNEL_SYSCALL:
458 ret = -EINVAL;
459 break;
460 case LTTNG_KERNEL_KPROBE:
461 case LTTNG_KERNEL_UPROBE:
462 case LTTNG_KERNEL_NOOP:
463 WRITE_ONCE(event->enabled, 0);
464 break;
465 case LTTNG_KERNEL_KRETPROBE:
466 ret = lttng_kretprobes_event_enable_state(event, 0);
467 break;
468 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
469 default:
470 WARN_ON_ONCE(1);
471 ret = -EINVAL;
472 }
473 end:
474 mutex_unlock(&sessions_mutex);
475 return ret;
476 }
477
478 static struct lttng_transport *lttng_transport_find(const char *name)
479 {
480 struct lttng_transport *transport;
481
482 list_for_each_entry(transport, &lttng_transport_list, node) {
483 if (!strcmp(transport->name, name))
484 return transport;
485 }
486 return NULL;
487 }
488
489 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
490 const char *transport_name,
491 void *buf_addr,
492 size_t subbuf_size, size_t num_subbuf,
493 unsigned int switch_timer_interval,
494 unsigned int read_timer_interval,
495 enum channel_type channel_type)
496 {
497 struct lttng_channel *chan;
498 struct lttng_transport *transport = NULL;
499
500 mutex_lock(&sessions_mutex);
501 if (session->been_active && channel_type != METADATA_CHANNEL)
502 goto active; /* Refuse to add channel to active session */
503 transport = lttng_transport_find(transport_name);
504 if (!transport) {
505 printk(KERN_WARNING "LTTng transport %s not found\n",
506 transport_name);
507 goto notransport;
508 }
509 if (!try_module_get(transport->owner)) {
510 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
511 goto notransport;
512 }
513 chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL);
514 if (!chan)
515 goto nomem;
516 chan->session = session;
517 chan->id = session->free_chan_id++;
518 chan->ops = &transport->ops;
519 /*
520 * Note: the channel creation op already writes into the packet
521 * headers. Therefore the "chan" information used as input
522 * should be already accessible.
523 */
524 chan->chan = transport->ops.channel_create(transport_name,
525 chan, buf_addr, subbuf_size, num_subbuf,
526 switch_timer_interval, read_timer_interval);
527 if (!chan->chan)
528 goto create_error;
529 chan->tstate = 1;
530 chan->enabled = 1;
531 chan->transport = transport;
532 chan->channel_type = channel_type;
533 list_add(&chan->list, &session->chan);
534 mutex_unlock(&sessions_mutex);
535 return chan;
536
537 create_error:
538 kfree(chan);
539 nomem:
540 if (transport)
541 module_put(transport->owner);
542 notransport:
543 active:
544 mutex_unlock(&sessions_mutex);
545 return NULL;
546 }
547
548 /*
549 * Only used internally at session destruction for per-cpu channels, and
550 * when metadata channel is released.
551 * Needs to be called with sessions mutex held.
552 */
553 static
554 void _lttng_channel_destroy(struct lttng_channel *chan)
555 {
556 chan->ops->channel_destroy(chan->chan);
557 module_put(chan->transport->owner);
558 list_del(&chan->list);
559 lttng_destroy_context(chan->ctx);
560 kfree(chan);
561 }
562
563 void lttng_metadata_channel_destroy(struct lttng_channel *chan)
564 {
565 BUG_ON(chan->channel_type != METADATA_CHANNEL);
566
567 /* Protect the metadata cache with the sessions_mutex. */
568 mutex_lock(&sessions_mutex);
569 _lttng_channel_destroy(chan);
570 mutex_unlock(&sessions_mutex);
571 }
572 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
573
574 static
575 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
576 {
577 stream->finalized = 1;
578 wake_up_interruptible(&stream->read_wait);
579 }
580
581 /*
582 * Supports event creation while tracing session is active.
583 * Needs to be called with sessions mutex held.
584 */
585 struct lttng_event *_lttng_event_create(struct lttng_channel *chan,
586 struct lttng_kernel_event *event_param,
587 void *filter,
588 const struct lttng_event_desc *event_desc,
589 enum lttng_kernel_instrumentation itype)
590 {
591 struct lttng_session *session = chan->session;
592 struct lttng_event *event;
593 const char *event_name;
594 struct hlist_head *head;
595 size_t name_len;
596 uint32_t hash;
597 int ret;
598
599 if (chan->free_event_id == -1U) {
600 ret = -EMFILE;
601 goto full;
602 }
603
604 switch (itype) {
605 case LTTNG_KERNEL_TRACEPOINT:
606 event_name = event_desc->name;
607 break;
608 case LTTNG_KERNEL_KPROBE:
609 case LTTNG_KERNEL_UPROBE:
610 case LTTNG_KERNEL_KRETPROBE:
611 case LTTNG_KERNEL_NOOP:
612 case LTTNG_KERNEL_SYSCALL:
613 event_name = event_param->name;
614 break;
615 case LTTNG_KERNEL_FUNCTION: /* Fall-through. */
616 default:
617 WARN_ON_ONCE(1);
618 ret = -EINVAL;
619 goto type_error;
620 }
621 name_len = strlen(event_name);
622 hash = jhash(event_name, name_len, 0);
623 head = &session->events_ht.table[hash & (LTTNG_EVENT_HT_SIZE - 1)];
624 lttng_hlist_for_each_entry(event, head, hlist) {
625 WARN_ON_ONCE(!event->desc);
626 if (!strncmp(event->desc->name, event_name,
627 LTTNG_KERNEL_SYM_NAME_LEN - 1)
628 && chan == event->chan) {
629 ret = -EEXIST;
630 goto exist;
631 }
632 }
633
634 event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
635 if (!event) {
636 ret = -ENOMEM;
637 goto cache_error;
638 }
639 event->chan = chan;
640 event->filter = filter;
641 event->id = chan->free_event_id++;
642 event->instrumentation = itype;
643 event->evtype = LTTNG_TYPE_EVENT;
644 INIT_LIST_HEAD(&event->bytecode_runtime_head);
645 INIT_LIST_HEAD(&event->enablers_ref_head);
646
647 switch (itype) {
648 case LTTNG_KERNEL_TRACEPOINT:
649 /* Event will be enabled by enabler sync. */
650 event->enabled = 0;
651 event->registered = 0;
652 event->desc = lttng_event_get(event_name);
653 if (!event->desc) {
654 ret = -ENOENT;
655 goto register_error;
656 }
657 /* Populate lttng_event structure before event registration. */
658 smp_wmb();
659 break;
660 case LTTNG_KERNEL_KPROBE:
661 /*
662 * Needs to be explicitly enabled after creation, since
663 * we may want to apply filters.
664 */
665 event->enabled = 0;
666 event->registered = 1;
667 /*
668 * Populate lttng_event structure before event
669 * registration.
670 */
671 smp_wmb();
672 ret = lttng_kprobes_register(event_name,
673 event_param->u.kprobe.symbol_name,
674 event_param->u.kprobe.offset,
675 event_param->u.kprobe.addr,
676 event);
677 if (ret) {
678 ret = -EINVAL;
679 goto register_error;
680 }
681 ret = try_module_get(event->desc->owner);
682 WARN_ON_ONCE(!ret);
683 break;
684 case LTTNG_KERNEL_KRETPROBE:
685 {
686 struct lttng_event *event_return;
687
688 /* kretprobe defines 2 events */
689 /*
690 * Needs to be explicitly enabled after creation, since
691 * we may want to apply filters.
692 */
693 event->enabled = 0;
694 event->registered = 1;
695 event_return =
696 kmem_cache_zalloc(event_cache, GFP_KERNEL);
697 if (!event_return) {
698 ret = -ENOMEM;
699 goto register_error;
700 }
701 event_return->chan = chan;
702 event_return->filter = filter;
703 event_return->id = chan->free_event_id++;
704 event_return->enabled = 0;
705 event_return->registered = 1;
706 event_return->instrumentation = itype;
707 INIT_LIST_HEAD(&event_return->bytecode_runtime_head);
708 INIT_LIST_HEAD(&event_return->enablers_ref_head);
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 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
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 lttng_free_event_filter_runtime(event);
952 /* Free event enabler refs */
953 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
954 &event->enablers_ref_head, node)
955 kfree(enabler_ref);
956 kmem_cache_free(event_cache, event);
957 }
958
959 struct lttng_id_tracker *get_tracker(struct lttng_session *session,
960 enum tracker_type tracker_type)
961 {
962 switch (tracker_type) {
963 case TRACKER_PID:
964 return &session->pid_tracker;
965 case TRACKER_VPID:
966 return &session->vpid_tracker;
967 case TRACKER_UID:
968 return &session->uid_tracker;
969 case TRACKER_VUID:
970 return &session->vuid_tracker;
971 case TRACKER_GID:
972 return &session->gid_tracker;
973 case TRACKER_VGID:
974 return &session->vgid_tracker;
975 default:
976 WARN_ON_ONCE(1);
977 return NULL;
978 }
979 }
980
981 int lttng_session_track_id(struct lttng_session *session,
982 enum tracker_type tracker_type, int id)
983 {
984 struct lttng_id_tracker *tracker;
985 int ret;
986
987 tracker = get_tracker(session, tracker_type);
988 if (!tracker)
989 return -EINVAL;
990 if (id < -1)
991 return -EINVAL;
992 mutex_lock(&sessions_mutex);
993 if (id == -1) {
994 /* track all ids: destroy tracker. */
995 lttng_id_tracker_destroy(tracker, true);
996 ret = 0;
997 } else {
998 ret = lttng_id_tracker_add(tracker, id);
999 }
1000 mutex_unlock(&sessions_mutex);
1001 return ret;
1002 }
1003
1004 int lttng_session_untrack_id(struct lttng_session *session,
1005 enum tracker_type tracker_type, int id)
1006 {
1007 struct lttng_id_tracker *tracker;
1008 int ret;
1009
1010 tracker = get_tracker(session, tracker_type);
1011 if (!tracker)
1012 return -EINVAL;
1013 if (id < -1)
1014 return -EINVAL;
1015 mutex_lock(&sessions_mutex);
1016 if (id == -1) {
1017 /* untrack all ids: replace by empty tracker. */
1018 ret = lttng_id_tracker_empty_set(tracker);
1019 } else {
1020 ret = lttng_id_tracker_del(tracker, id);
1021 }
1022 mutex_unlock(&sessions_mutex);
1023 return ret;
1024 }
1025
1026 static
1027 void *id_list_start(struct seq_file *m, loff_t *pos)
1028 {
1029 struct lttng_id_tracker *id_tracker = m->private;
1030 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1031 struct lttng_id_hash_node *e;
1032 int iter = 0, i;
1033
1034 mutex_lock(&sessions_mutex);
1035 if (id_tracker_p) {
1036 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1037 struct hlist_head *head = &id_tracker_p->id_hash[i];
1038
1039 lttng_hlist_for_each_entry(e, head, hlist) {
1040 if (iter++ >= *pos)
1041 return e;
1042 }
1043 }
1044 } else {
1045 /* ID tracker disabled. */
1046 if (iter >= *pos && iter == 0) {
1047 return id_tracker_p; /* empty tracker */
1048 }
1049 iter++;
1050 }
1051 /* End of list */
1052 return NULL;
1053 }
1054
1055 /* Called with sessions_mutex held. */
1056 static
1057 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1058 {
1059 struct lttng_id_tracker *id_tracker = m->private;
1060 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1061 struct lttng_id_hash_node *e;
1062 int iter = 0, i;
1063
1064 (*ppos)++;
1065 if (id_tracker_p) {
1066 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1067 struct hlist_head *head = &id_tracker_p->id_hash[i];
1068
1069 lttng_hlist_for_each_entry(e, head, hlist) {
1070 if (iter++ >= *ppos)
1071 return e;
1072 }
1073 }
1074 } else {
1075 /* ID tracker disabled. */
1076 if (iter >= *ppos && iter == 0)
1077 return p; /* empty tracker */
1078 iter++;
1079 }
1080
1081 /* End of list */
1082 return NULL;
1083 }
1084
1085 static
1086 void id_list_stop(struct seq_file *m, void *p)
1087 {
1088 mutex_unlock(&sessions_mutex);
1089 }
1090
1091 static
1092 int id_list_show(struct seq_file *m, void *p)
1093 {
1094 struct lttng_id_tracker *id_tracker = m->private;
1095 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1096 int id;
1097
1098 if (p == id_tracker_p) {
1099 /* Tracker disabled. */
1100 id = -1;
1101 } else {
1102 const struct lttng_id_hash_node *e = p;
1103
1104 id = lttng_id_tracker_get_node_id(e);
1105 }
1106 switch (id_tracker->tracker_type) {
1107 case TRACKER_PID:
1108 seq_printf(m, "process { pid = %d; };\n", id);
1109 break;
1110 case TRACKER_VPID:
1111 seq_printf(m, "process { vpid = %d; };\n", id);
1112 break;
1113 case TRACKER_UID:
1114 seq_printf(m, "user { uid = %d; };\n", id);
1115 break;
1116 case TRACKER_VUID:
1117 seq_printf(m, "user { vuid = %d; };\n", id);
1118 break;
1119 case TRACKER_GID:
1120 seq_printf(m, "group { gid = %d; };\n", id);
1121 break;
1122 case TRACKER_VGID:
1123 seq_printf(m, "group { vgid = %d; };\n", id);
1124 break;
1125 default:
1126 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1127 }
1128 return 0;
1129 }
1130
1131 static
1132 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1133 .start = id_list_start,
1134 .next = id_list_next,
1135 .stop = id_list_stop,
1136 .show = id_list_show,
1137 };
1138
1139 static
1140 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1141 {
1142 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1143 }
1144
1145 static
1146 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1147 {
1148 struct seq_file *m = file->private_data;
1149 struct lttng_id_tracker *id_tracker = m->private;
1150 int ret;
1151
1152 WARN_ON_ONCE(!id_tracker);
1153 ret = seq_release(inode, file);
1154 if (!ret)
1155 fput(id_tracker->session->file);
1156 return ret;
1157 }
1158
1159 const struct file_operations lttng_tracker_ids_list_fops = {
1160 .owner = THIS_MODULE,
1161 .open = lttng_tracker_ids_list_open,
1162 .read = seq_read,
1163 .llseek = seq_lseek,
1164 .release = lttng_tracker_ids_list_release,
1165 };
1166
1167 int lttng_session_list_tracker_ids(struct lttng_session *session,
1168 enum tracker_type tracker_type)
1169 {
1170 struct file *tracker_ids_list_file;
1171 struct seq_file *m;
1172 int file_fd, ret;
1173
1174 file_fd = lttng_get_unused_fd();
1175 if (file_fd < 0) {
1176 ret = file_fd;
1177 goto fd_error;
1178 }
1179
1180 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1181 &lttng_tracker_ids_list_fops,
1182 NULL, O_RDWR);
1183 if (IS_ERR(tracker_ids_list_file)) {
1184 ret = PTR_ERR(tracker_ids_list_file);
1185 goto file_error;
1186 }
1187 if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
1188 ret = -EOVERFLOW;
1189 goto refcount_error;
1190 }
1191 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1192 if (ret < 0)
1193 goto open_error;
1194 m = tracker_ids_list_file->private_data;
1195
1196 m->private = get_tracker(session, tracker_type);
1197 BUG_ON(!m->private);
1198 fd_install(file_fd, tracker_ids_list_file);
1199
1200 return file_fd;
1201
1202 open_error:
1203 atomic_long_dec(&session->file->f_count);
1204 refcount_error:
1205 fput(tracker_ids_list_file);
1206 file_error:
1207 put_unused_fd(file_fd);
1208 fd_error:
1209 return ret;
1210 }
1211
1212 /*
1213 * Enabler management.
1214 */
1215 static
1216 int lttng_match_enabler_star_glob(const char *desc_name,
1217 const char *pattern)
1218 {
1219 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1220 desc_name, LTTNG_SIZE_MAX))
1221 return 0;
1222 return 1;
1223 }
1224
1225 static
1226 int lttng_match_enabler_name(const char *desc_name,
1227 const char *name)
1228 {
1229 if (strcmp(desc_name, name))
1230 return 0;
1231 return 1;
1232 }
1233
1234 static
1235 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
1236 struct lttng_enabler *enabler)
1237 {
1238 const char *desc_name, *enabler_name;
1239 bool compat = false, entry = false;
1240
1241 enabler_name = enabler->event_param.name;
1242 switch (enabler->event_param.instrumentation) {
1243 case LTTNG_KERNEL_TRACEPOINT:
1244 desc_name = desc->name;
1245 switch (enabler->type) {
1246 case LTTNG_ENABLER_STAR_GLOB:
1247 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1248 case LTTNG_ENABLER_NAME:
1249 return lttng_match_enabler_name(desc_name, enabler_name);
1250 default:
1251 return -EINVAL;
1252 }
1253 break;
1254 case LTTNG_KERNEL_SYSCALL:
1255 desc_name = desc->name;
1256 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1257 desc_name += strlen("compat_");
1258 compat = true;
1259 }
1260 if (!strncmp(desc_name, "syscall_exit_",
1261 strlen("syscall_exit_"))) {
1262 desc_name += strlen("syscall_exit_");
1263 } else if (!strncmp(desc_name, "syscall_entry_",
1264 strlen("syscall_entry_"))) {
1265 desc_name += strlen("syscall_entry_");
1266 entry = true;
1267 } else {
1268 WARN_ON_ONCE(1);
1269 return -EINVAL;
1270 }
1271 switch (enabler->event_param.u.syscall.entryexit) {
1272 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1273 break;
1274 case LTTNG_KERNEL_SYSCALL_ENTRY:
1275 if (!entry)
1276 return 0;
1277 break;
1278 case LTTNG_KERNEL_SYSCALL_EXIT:
1279 if (entry)
1280 return 0;
1281 break;
1282 default:
1283 return -EINVAL;
1284 }
1285 switch (enabler->event_param.u.syscall.abi) {
1286 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1287 break;
1288 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1289 if (compat)
1290 return 0;
1291 break;
1292 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1293 if (!compat)
1294 return 0;
1295 break;
1296 default:
1297 return -EINVAL;
1298 }
1299 switch (enabler->event_param.u.syscall.match) {
1300 case LTTNG_SYSCALL_MATCH_NAME:
1301 switch (enabler->type) {
1302 case LTTNG_ENABLER_STAR_GLOB:
1303 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1304 case LTTNG_ENABLER_NAME:
1305 return lttng_match_enabler_name(desc_name, enabler_name);
1306 default:
1307 return -EINVAL;
1308 }
1309 break;
1310 case LTTNG_SYSCALL_MATCH_NR:
1311 return -EINVAL; /* Not implemented. */
1312 default:
1313 return -EINVAL;
1314 }
1315 break;
1316 default:
1317 WARN_ON_ONCE(1);
1318 return -EINVAL;
1319 }
1320 }
1321
1322 static
1323 int lttng_event_match_enabler(struct lttng_event *event,
1324 struct lttng_enabler *enabler)
1325 {
1326 if (enabler->event_param.instrumentation != event->instrumentation)
1327 return 0;
1328 if (lttng_desc_match_enabler(event->desc, enabler)
1329 && event->chan == enabler->chan)
1330 return 1;
1331 else
1332 return 0;
1333 }
1334
1335 static
1336 struct lttng_enabler_ref *lttng_event_enabler_ref(struct lttng_event *event,
1337 struct lttng_enabler *enabler)
1338 {
1339 struct lttng_enabler_ref *enabler_ref;
1340
1341 list_for_each_entry(enabler_ref,
1342 &event->enablers_ref_head, node) {
1343 if (enabler_ref->ref == enabler)
1344 return enabler_ref;
1345 }
1346 return NULL;
1347 }
1348
1349 static
1350 void lttng_create_tracepoint_if_missing(struct lttng_enabler *enabler)
1351 {
1352 struct lttng_session *session = enabler->chan->session;
1353 struct lttng_probe_desc *probe_desc;
1354 const struct lttng_event_desc *desc;
1355 int i;
1356 struct list_head *probe_list;
1357
1358 probe_list = lttng_get_probe_list_head();
1359 /*
1360 * For each probe event, if we find that a probe event matches
1361 * our enabler, create an associated lttng_event if not
1362 * already present.
1363 */
1364 list_for_each_entry(probe_desc, probe_list, head) {
1365 for (i = 0; i < probe_desc->nr_events; i++) {
1366 int found = 0;
1367 struct hlist_head *head;
1368 const char *event_name;
1369 size_t name_len;
1370 uint32_t hash;
1371 struct lttng_event *event;
1372
1373 desc = probe_desc->event_desc[i];
1374 if (!lttng_desc_match_enabler(desc, enabler))
1375 continue;
1376 event_name = desc->name;
1377 name_len = strlen(event_name);
1378
1379 /*
1380 * Check if already created.
1381 */
1382 hash = jhash(event_name, name_len, 0);
1383 head = &session->events_ht.table[hash & (LTTNG_EVENT_HT_SIZE - 1)];
1384 lttng_hlist_for_each_entry(event, head, hlist) {
1385 if (event->desc == desc
1386 && event->chan == enabler->chan)
1387 found = 1;
1388 }
1389 if (found)
1390 continue;
1391
1392 /*
1393 * We need to create an event for this
1394 * event probe.
1395 */
1396 event = _lttng_event_create(enabler->chan,
1397 NULL, NULL, desc,
1398 LTTNG_KERNEL_TRACEPOINT);
1399 if (!event) {
1400 printk(KERN_INFO "Unable to create event %s\n",
1401 probe_desc->event_desc[i]->name);
1402 }
1403 }
1404 }
1405 }
1406
1407 static
1408 void lttng_create_syscall_if_missing(struct lttng_enabler *enabler)
1409 {
1410 int ret;
1411
1412 ret = lttng_syscalls_register(enabler->chan, NULL);
1413 WARN_ON_ONCE(ret);
1414 }
1415
1416 /*
1417 * Create struct lttng_event if it is missing and present in the list of
1418 * tracepoint probes.
1419 * Should be called with sessions mutex held.
1420 */
1421 static
1422 void lttng_create_event_if_missing(struct lttng_enabler *enabler)
1423 {
1424 switch (enabler->event_param.instrumentation) {
1425 case LTTNG_KERNEL_TRACEPOINT:
1426 lttng_create_tracepoint_if_missing(enabler);
1427 break;
1428 case LTTNG_KERNEL_SYSCALL:
1429 lttng_create_syscall_if_missing(enabler);
1430 break;
1431 default:
1432 WARN_ON_ONCE(1);
1433 break;
1434 }
1435 }
1436
1437 /*
1438 * Create events associated with an enabler (if not already present),
1439 * and add backward reference from the event to the enabler.
1440 * Should be called with sessions mutex held.
1441 */
1442 static
1443 int lttng_enabler_ref_events(struct lttng_enabler *enabler)
1444 {
1445 struct lttng_channel *chan = enabler->chan;
1446 struct lttng_session *session = chan->session;
1447 struct lttng_event *event;
1448
1449 if (enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
1450 enabler->event_param.u.syscall.entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT &&
1451 enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
1452 enabler->event_param.u.syscall.match == LTTNG_SYSCALL_MATCH_NAME &&
1453 !strcmp(enabler->event_param.name, "*")) {
1454 if (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(enabler);
1462
1463 /* For each event matching 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_match_enabler(event, enabler))
1468 continue;
1469 enabler_ref = lttng_event_enabler_ref(event, enabler);
1470 if (!enabler_ref) {
1471 /*
1472 * If no backward ref, create it.
1473 * Add backward ref from event to enabler.
1474 */
1475 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
1476 if (!enabler_ref)
1477 return -ENOMEM;
1478 enabler_ref->ref = enabler;
1479 list_add(&enabler_ref->node,
1480 &event->enablers_ref_head);
1481 }
1482
1483 /*
1484 * Link filter bytecodes if not linked yet.
1485 */
1486 lttng_enabler_event_link_bytecode(event, enabler);
1487
1488 /* TODO: merge event context. */
1489 }
1490 return 0;
1491 }
1492
1493 /*
1494 * Called at module load: connect the probe on all enablers matching
1495 * this event.
1496 * Called with sessions lock held.
1497 */
1498 int lttng_fix_pending_events(void)
1499 {
1500 struct lttng_session *session;
1501
1502 list_for_each_entry(session, &sessions, list)
1503 lttng_session_lazy_sync_enablers(session);
1504 return 0;
1505 }
1506
1507 struct lttng_enabler *lttng_enabler_create(enum lttng_enabler_type type,
1508 struct lttng_kernel_event *event_param,
1509 struct lttng_channel *chan)
1510 {
1511 struct lttng_enabler *enabler;
1512
1513 enabler = kzalloc(sizeof(*enabler), GFP_KERNEL);
1514 if (!enabler)
1515 return NULL;
1516 enabler->type = type;
1517 INIT_LIST_HEAD(&enabler->filter_bytecode_head);
1518 memcpy(&enabler->event_param, event_param,
1519 sizeof(enabler->event_param));
1520 enabler->chan = chan;
1521 /* ctx left NULL */
1522 enabler->enabled = 0;
1523 enabler->evtype = LTTNG_TYPE_ENABLER;
1524 mutex_lock(&sessions_mutex);
1525 list_add(&enabler->node, &enabler->chan->session->enablers_head);
1526 lttng_session_lazy_sync_enablers(enabler->chan->session);
1527 mutex_unlock(&sessions_mutex);
1528 return enabler;
1529 }
1530
1531 int lttng_enabler_enable(struct lttng_enabler *enabler)
1532 {
1533 mutex_lock(&sessions_mutex);
1534 enabler->enabled = 1;
1535 lttng_session_lazy_sync_enablers(enabler->chan->session);
1536 mutex_unlock(&sessions_mutex);
1537 return 0;
1538 }
1539
1540 int lttng_enabler_disable(struct lttng_enabler *enabler)
1541 {
1542 mutex_lock(&sessions_mutex);
1543 enabler->enabled = 0;
1544 lttng_session_lazy_sync_enablers(enabler->chan->session);
1545 mutex_unlock(&sessions_mutex);
1546 return 0;
1547 }
1548
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 bytecode_node->enabler = enabler;
1568 /* Enforce length based on allocated size */
1569 bytecode_node->bc.len = bytecode_len;
1570 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
1571 lttng_session_lazy_sync_enablers(enabler->chan->session);
1572 return 0;
1573
1574 error_free:
1575 kfree(bytecode_node);
1576 return ret;
1577 }
1578
1579 int lttng_event_add_callsite(struct lttng_event *event,
1580 struct lttng_kernel_event_callsite __user *callsite)
1581 {
1582
1583 switch (event->instrumentation) {
1584 case LTTNG_KERNEL_UPROBE:
1585 return lttng_uprobes_add_callsite(event, callsite);
1586 default:
1587 return -EINVAL;
1588 }
1589 }
1590
1591 int lttng_enabler_attach_context(struct lttng_enabler *enabler,
1592 struct lttng_kernel_context *context_param)
1593 {
1594 return -ENOSYS;
1595 }
1596
1597 static
1598 void lttng_enabler_destroy(struct lttng_enabler *enabler)
1599 {
1600 struct lttng_filter_bytecode_node *filter_node, *tmp_filter_node;
1601
1602 /* Destroy filter bytecode */
1603 list_for_each_entry_safe(filter_node, tmp_filter_node,
1604 &enabler->filter_bytecode_head, node) {
1605 kfree(filter_node);
1606 }
1607
1608 /* Destroy contexts */
1609 lttng_destroy_context(enabler->ctx);
1610
1611 list_del(&enabler->node);
1612 kfree(enabler);
1613 }
1614
1615 /*
1616 * lttng_session_sync_enablers should be called just before starting a
1617 * session.
1618 * Should be called with sessions mutex held.
1619 */
1620 static
1621 void lttng_session_sync_enablers(struct lttng_session *session)
1622 {
1623 struct lttng_enabler *enabler;
1624 struct lttng_event *event;
1625
1626 list_for_each_entry(enabler, &session->enablers_head, node)
1627 lttng_enabler_ref_events(enabler);
1628 /*
1629 * For each event, if at least one of its enablers is enabled,
1630 * and its channel and session transient states are enabled, we
1631 * enable the event, else we disable it.
1632 */
1633 list_for_each_entry(event, &session->events, list) {
1634 struct lttng_enabler_ref *enabler_ref;
1635 struct lttng_bytecode_runtime *runtime;
1636 int enabled = 0, has_enablers_without_bytecode = 0;
1637
1638 switch (event->instrumentation) {
1639 case LTTNG_KERNEL_TRACEPOINT:
1640 case LTTNG_KERNEL_SYSCALL:
1641 /* Enable events */
1642 list_for_each_entry(enabler_ref,
1643 &event->enablers_ref_head, node) {
1644 if (enabler_ref->ref->enabled) {
1645 enabled = 1;
1646 break;
1647 }
1648 }
1649 break;
1650 default:
1651 /* Not handled with lazy sync. */
1652 continue;
1653 }
1654 /*
1655 * Enabled state is based on union of enablers, with
1656 * intesection of session and channel transient enable
1657 * states.
1658 */
1659 enabled = enabled && session->tstate && event->chan->tstate;
1660
1661 WRITE_ONCE(event->enabled, enabled);
1662 /*
1663 * Sync tracepoint registration with event enabled
1664 * state.
1665 */
1666 if (enabled) {
1667 register_event(event);
1668 } else {
1669 _lttng_event_unregister(event);
1670 }
1671
1672 /* Check if has enablers without bytecode enabled */
1673 list_for_each_entry(enabler_ref,
1674 &event->enablers_ref_head, node) {
1675 if (enabler_ref->ref->enabled
1676 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
1677 has_enablers_without_bytecode = 1;
1678 break;
1679 }
1680 }
1681 event->has_enablers_without_bytecode =
1682 has_enablers_without_bytecode;
1683
1684 /* Enable filters */
1685 list_for_each_entry(runtime,
1686 &event->bytecode_runtime_head, node)
1687 lttng_filter_sync_state(runtime);
1688 }
1689 }
1690
1691 /*
1692 * Apply enablers to session events, adding events to session if need
1693 * be. It is required after each modification applied to an active
1694 * session, and right before session "start".
1695 * "lazy" sync means we only sync if required.
1696 * Should be called with sessions mutex held.
1697 */
1698 static
1699 void lttng_session_lazy_sync_enablers(struct lttng_session *session)
1700 {
1701 /* We can skip if session is not active */
1702 if (!session->active)
1703 return;
1704 lttng_session_sync_enablers(session);
1705 }
1706
1707 /*
1708 * Serialize at most one packet worth of metadata into a metadata
1709 * channel.
1710 * We grab the metadata cache mutex to get exclusive access to our metadata
1711 * buffer and to the metadata cache. Exclusive access to the metadata buffer
1712 * allows us to do racy operations such as looking for remaining space left in
1713 * packet and write, since mutual exclusion protects us from concurrent writes.
1714 * Mutual exclusion on the metadata cache allow us to read the cache content
1715 * without racing against reallocation of the cache by updates.
1716 * Returns the number of bytes written in the channel, 0 if no data
1717 * was written and a negative value on error.
1718 */
1719 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
1720 struct channel *chan, bool *coherent)
1721 {
1722 struct lib_ring_buffer_ctx ctx;
1723 int ret = 0;
1724 size_t len, reserve_len;
1725
1726 /*
1727 * Ensure we support mutiple get_next / put sequences followed by
1728 * put_next. The metadata cache lock protects reading the metadata
1729 * cache. It can indeed be read concurrently by "get_next_subbuf" and
1730 * "flush" operations on the buffer invoked by different processes.
1731 * Moreover, since the metadata cache memory can be reallocated, we
1732 * need to have exclusive access against updates even though we only
1733 * read it.
1734 */
1735 mutex_lock(&stream->metadata_cache->lock);
1736 WARN_ON(stream->metadata_in < stream->metadata_out);
1737 if (stream->metadata_in != stream->metadata_out)
1738 goto end;
1739
1740 /* Metadata regenerated, change the version. */
1741 if (stream->metadata_cache->version != stream->version)
1742 stream->version = stream->metadata_cache->version;
1743
1744 len = stream->metadata_cache->metadata_written -
1745 stream->metadata_in;
1746 if (!len)
1747 goto end;
1748 reserve_len = min_t(size_t,
1749 stream->transport->ops.packet_avail_size(chan),
1750 len);
1751 lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
1752 sizeof(char), -1);
1753 /*
1754 * If reservation failed, return an error to the caller.
1755 */
1756 ret = stream->transport->ops.event_reserve(&ctx, 0);
1757 if (ret != 0) {
1758 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
1759 stream->coherent = false;
1760 goto end;
1761 }
1762 stream->transport->ops.event_write(&ctx,
1763 stream->metadata_cache->data + stream->metadata_in,
1764 reserve_len);
1765 stream->transport->ops.event_commit(&ctx);
1766 stream->metadata_in += reserve_len;
1767 if (reserve_len < len)
1768 stream->coherent = false;
1769 else
1770 stream->coherent = true;
1771 ret = reserve_len;
1772
1773 end:
1774 if (coherent)
1775 *coherent = stream->coherent;
1776 mutex_unlock(&stream->metadata_cache->lock);
1777 return ret;
1778 }
1779
1780 static
1781 void lttng_metadata_begin(struct lttng_session *session)
1782 {
1783 if (atomic_inc_return(&session->metadata_cache->producing) == 1)
1784 mutex_lock(&session->metadata_cache->lock);
1785 }
1786
1787 static
1788 void lttng_metadata_end(struct lttng_session *session)
1789 {
1790 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
1791 if (atomic_dec_return(&session->metadata_cache->producing) == 0) {
1792 struct lttng_metadata_stream *stream;
1793
1794 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
1795 wake_up_interruptible(&stream->read_wait);
1796 mutex_unlock(&session->metadata_cache->lock);
1797 }
1798 }
1799
1800 /*
1801 * Write the metadata to the metadata cache.
1802 * Must be called with sessions_mutex held.
1803 * The metadata cache lock protects us from concurrent read access from
1804 * thread outputting metadata content to ring buffer.
1805 * The content of the printf is printed as a single atomic metadata
1806 * transaction.
1807 */
1808 int lttng_metadata_printf(struct lttng_session *session,
1809 const char *fmt, ...)
1810 {
1811 char *str;
1812 size_t len;
1813 va_list ap;
1814
1815 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
1816
1817 va_start(ap, fmt);
1818 str = kvasprintf(GFP_KERNEL, fmt, ap);
1819 va_end(ap);
1820 if (!str)
1821 return -ENOMEM;
1822
1823 len = strlen(str);
1824 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
1825 if (session->metadata_cache->metadata_written + len >
1826 session->metadata_cache->cache_alloc) {
1827 char *tmp_cache_realloc;
1828 unsigned int tmp_cache_alloc_size;
1829
1830 tmp_cache_alloc_size = max_t(unsigned int,
1831 session->metadata_cache->cache_alloc + len,
1832 session->metadata_cache->cache_alloc << 1);
1833 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
1834 if (!tmp_cache_realloc)
1835 goto err;
1836 if (session->metadata_cache->data) {
1837 memcpy(tmp_cache_realloc,
1838 session->metadata_cache->data,
1839 session->metadata_cache->cache_alloc);
1840 vfree(session->metadata_cache->data);
1841 }
1842
1843 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
1844 session->metadata_cache->data = tmp_cache_realloc;
1845 }
1846 memcpy(session->metadata_cache->data +
1847 session->metadata_cache->metadata_written,
1848 str, len);
1849 session->metadata_cache->metadata_written += len;
1850 kfree(str);
1851
1852 return 0;
1853
1854 err:
1855 kfree(str);
1856 return -ENOMEM;
1857 }
1858
1859 static
1860 int print_tabs(struct lttng_session *session, size_t nesting)
1861 {
1862 size_t i;
1863
1864 for (i = 0; i < nesting; i++) {
1865 int ret;
1866
1867 ret = lttng_metadata_printf(session, " ");
1868 if (ret) {
1869 return ret;
1870 }
1871 }
1872 return 0;
1873 }
1874
1875 /*
1876 * Must be called with sessions_mutex held.
1877 */
1878 static
1879 int _lttng_struct_type_statedump(struct lttng_session *session,
1880 const struct lttng_type *type,
1881 size_t nesting)
1882 {
1883 int ret;
1884 uint32_t i, nr_fields;
1885
1886 ret = print_tabs(session, nesting);
1887 if (ret)
1888 return ret;
1889 ret = lttng_metadata_printf(session,
1890 "struct {\n");
1891 if (ret)
1892 return ret;
1893 nr_fields = type->u._struct.nr_fields;
1894 for (i = 0; i < nr_fields; i++) {
1895 const struct lttng_event_field *iter_field;
1896
1897 iter_field = &type->u._struct.fields[i];
1898 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
1899 if (ret)
1900 return ret;
1901 }
1902 ret = print_tabs(session, nesting);
1903 if (ret)
1904 return ret;
1905 ret = lttng_metadata_printf(session,
1906 "}");
1907 return ret;
1908 }
1909
1910 /*
1911 * Must be called with sessions_mutex held.
1912 */
1913 static
1914 int _lttng_struct_statedump(struct lttng_session *session,
1915 const struct lttng_event_field *field,
1916 size_t nesting)
1917 {
1918 int ret;
1919
1920 ret = _lttng_struct_type_statedump(session,
1921 &field->type, nesting);
1922 if (ret)
1923 return ret;
1924 ret = lttng_metadata_printf(session,
1925 "_%s;\n",
1926 field->name);
1927 return ret;
1928 }
1929
1930 /*
1931 * Must be called with sessions_mutex held.
1932 */
1933 static
1934 int _lttng_variant_type_statedump(struct lttng_session *session,
1935 const struct lttng_type *type,
1936 size_t nesting)
1937 {
1938 int ret;
1939 uint32_t i, nr_choices;
1940
1941 ret = print_tabs(session, nesting);
1942 if (ret)
1943 return ret;
1944 ret = lttng_metadata_printf(session,
1945 "variant <_%s> {\n",
1946 type->u.variant.tag_name);
1947 if (ret)
1948 return ret;
1949 nr_choices = type->u.variant.nr_choices;
1950 for (i = 0; i < nr_choices; i++) {
1951 const struct lttng_event_field *iter_field;
1952
1953 iter_field = &type->u.variant.choices[i];
1954 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
1955 if (ret)
1956 return ret;
1957 }
1958 ret = print_tabs(session, nesting);
1959 if (ret)
1960 return ret;
1961 ret = lttng_metadata_printf(session,
1962 "}");
1963 return ret;
1964 }
1965
1966 /*
1967 * Must be called with sessions_mutex held.
1968 */
1969 static
1970 int _lttng_variant_statedump(struct lttng_session *session,
1971 const struct lttng_event_field *field,
1972 size_t nesting)
1973 {
1974 int ret;
1975
1976 ret = _lttng_variant_type_statedump(session,
1977 &field->type, nesting);
1978 if (ret)
1979 return ret;
1980 ret = lttng_metadata_printf(session,
1981 "_%s;\n",
1982 field->name);
1983 return ret;
1984 }
1985
1986 /*
1987 * Must be called with sessions_mutex held.
1988 */
1989 static
1990 int _lttng_array_compound_statedump(struct lttng_session *session,
1991 const struct lttng_event_field *field,
1992 size_t nesting)
1993 {
1994 int ret;
1995 const struct lttng_type *elem_type;
1996
1997 /* Only array of structures and variants are currently supported. */
1998 elem_type = field->type.u.array_compound.elem_type;
1999 switch (elem_type->atype) {
2000 case atype_struct:
2001 ret = _lttng_struct_type_statedump(session, elem_type, nesting);
2002 if (ret)
2003 return ret;
2004 break;
2005 case atype_variant:
2006 ret = _lttng_variant_type_statedump(session, elem_type, nesting);
2007 if (ret)
2008 return ret;
2009 break;
2010 default:
2011 return -EINVAL;
2012 }
2013 ret = lttng_metadata_printf(session,
2014 " _%s[%u];\n",
2015 field->name,
2016 field->type.u.array_compound.length);
2017 return ret;
2018 }
2019
2020 /*
2021 * Must be called with sessions_mutex held.
2022 */
2023 static
2024 int _lttng_sequence_compound_statedump(struct lttng_session *session,
2025 const struct lttng_event_field *field,
2026 size_t nesting)
2027 {
2028 int ret;
2029 const char *length_name;
2030 const struct lttng_type *elem_type;
2031
2032 length_name = field->type.u.sequence_compound.length_name;
2033
2034 /* Only array of structures and variants are currently supported. */
2035 elem_type = field->type.u.sequence_compound.elem_type;
2036 switch (elem_type->atype) {
2037 case atype_struct:
2038 ret = _lttng_struct_type_statedump(session, elem_type, nesting);
2039 if (ret)
2040 return ret;
2041 break;
2042 case atype_variant:
2043 ret = _lttng_variant_type_statedump(session, elem_type, nesting);
2044 if (ret)
2045 return ret;
2046 break;
2047 default:
2048 return -EINVAL;
2049 }
2050 ret = lttng_metadata_printf(session,
2051 " _%s[ _%s ];\n",
2052 field->name,
2053 length_name);
2054 return ret;
2055 }
2056
2057 /*
2058 * Must be called with sessions_mutex held.
2059 */
2060 static
2061 int _lttng_enum_statedump(struct lttng_session *session,
2062 const struct lttng_event_field *field,
2063 size_t nesting)
2064 {
2065 const struct lttng_enum_desc *enum_desc;
2066 const struct lttng_integer_type *container_type;
2067 int ret;
2068 unsigned int i, nr_entries;
2069
2070 enum_desc = field->type.u.basic.enumeration.desc;
2071 container_type = &field->type.u.basic.enumeration.container_type;
2072 nr_entries = enum_desc->nr_entries;
2073
2074 ret = print_tabs(session, nesting);
2075 if (ret)
2076 goto end;
2077 ret = lttng_metadata_printf(session,
2078 "enum : integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } {\n",
2079 container_type->size,
2080 container_type->alignment,
2081 container_type->signedness,
2082 (container_type->encoding == lttng_encode_none)
2083 ? "none"
2084 : (container_type->encoding == lttng_encode_UTF8)
2085 ? "UTF8"
2086 : "ASCII",
2087 container_type->base,
2088 #if __BYTE_ORDER == __BIG_ENDIAN
2089 container_type->reverse_byte_order ? " byte_order = le;" : ""
2090 #else
2091 container_type->reverse_byte_order ? " byte_order = be;" : ""
2092 #endif
2093 );
2094 if (ret)
2095 goto end;
2096 /* Dump all entries */
2097 for (i = 0; i < nr_entries; i++) {
2098 const struct lttng_enum_entry *entry = &enum_desc->entries[i];
2099 int j, len;
2100
2101 ret = print_tabs(session, nesting + 1);
2102 if (ret)
2103 goto end;
2104 ret = lttng_metadata_printf(session,
2105 "\"");
2106 if (ret)
2107 goto end;
2108 len = strlen(entry->string);
2109 /* Escape the character '"' */
2110 for (j = 0; j < len; j++) {
2111 char c = entry->string[j];
2112
2113 switch (c) {
2114 case '"':
2115 ret = lttng_metadata_printf(session,
2116 "\\\"");
2117 break;
2118 case '\\':
2119 ret = lttng_metadata_printf(session,
2120 "\\\\");
2121 break;
2122 default:
2123 ret = lttng_metadata_printf(session,
2124 "%c", c);
2125 break;
2126 }
2127 if (ret)
2128 goto end;
2129 }
2130 ret = lttng_metadata_printf(session, "\"");
2131 if (ret)
2132 goto end;
2133
2134 if (entry->options.is_auto) {
2135 ret = lttng_metadata_printf(session, ",\n");
2136 if (ret)
2137 goto end;
2138 } else {
2139 ret = lttng_metadata_printf(session,
2140 " = ");
2141 if (ret)
2142 goto end;
2143 if (entry->start.signedness)
2144 ret = lttng_metadata_printf(session,
2145 "%lld", (long long) entry->start.value);
2146 else
2147 ret = lttng_metadata_printf(session,
2148 "%llu", entry->start.value);
2149 if (ret)
2150 goto end;
2151 if (entry->start.signedness == entry->end.signedness &&
2152 entry->start.value
2153 == entry->end.value) {
2154 ret = lttng_metadata_printf(session,
2155 ",\n");
2156 } else {
2157 if (entry->end.signedness) {
2158 ret = lttng_metadata_printf(session,
2159 " ... %lld,\n",
2160 (long long) entry->end.value);
2161 } else {
2162 ret = lttng_metadata_printf(session,
2163 " ... %llu,\n",
2164 entry->end.value);
2165 }
2166 }
2167 if (ret)
2168 goto end;
2169 }
2170 }
2171 ret = print_tabs(session, nesting);
2172 if (ret)
2173 goto end;
2174 ret = lttng_metadata_printf(session, "} _%s;\n",
2175 field->name);
2176 end:
2177 return ret;
2178 }
2179
2180 /*
2181 * Must be called with sessions_mutex held.
2182 */
2183 static
2184 int _lttng_field_statedump(struct lttng_session *session,
2185 const struct lttng_event_field *field,
2186 size_t nesting)
2187 {
2188 int ret = 0;
2189
2190 switch (field->type.atype) {
2191 case atype_integer:
2192 ret = print_tabs(session, nesting);
2193 if (ret)
2194 return ret;
2195 ret = lttng_metadata_printf(session,
2196 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
2197 field->type.u.basic.integer.size,
2198 field->type.u.basic.integer.alignment,
2199 field->type.u.basic.integer.signedness,
2200 (field->type.u.basic.integer.encoding == lttng_encode_none)
2201 ? "none"
2202 : (field->type.u.basic.integer.encoding == lttng_encode_UTF8)
2203 ? "UTF8"
2204 : "ASCII",
2205 field->type.u.basic.integer.base,
2206 #if __BYTE_ORDER == __BIG_ENDIAN
2207 field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2208 #else
2209 field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2210 #endif
2211 field->name);
2212 break;
2213 case atype_enum:
2214 ret = _lttng_enum_statedump(session, field, nesting);
2215 break;
2216 case atype_array:
2217 case atype_array_bitfield:
2218 {
2219 const struct lttng_basic_type *elem_type;
2220
2221 elem_type = &field->type.u.array.elem_type;
2222 if (field->type.u.array.elem_alignment) {
2223 ret = print_tabs(session, nesting);
2224 if (ret)
2225 return ret;
2226 ret = lttng_metadata_printf(session,
2227 "struct { } align(%u) _%s_padding;\n",
2228 field->type.u.array.elem_alignment * CHAR_BIT,
2229 field->name);
2230 if (ret)
2231 return ret;
2232 }
2233 ret = print_tabs(session, nesting);
2234 if (ret)
2235 return ret;
2236 ret = lttng_metadata_printf(session,
2237 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
2238 elem_type->u.basic.integer.size,
2239 elem_type->u.basic.integer.alignment,
2240 elem_type->u.basic.integer.signedness,
2241 (elem_type->u.basic.integer.encoding == lttng_encode_none)
2242 ? "none"
2243 : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
2244 ? "UTF8"
2245 : "ASCII",
2246 elem_type->u.basic.integer.base,
2247 #if __BYTE_ORDER == __BIG_ENDIAN
2248 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2249 #else
2250 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2251 #endif
2252 field->name, field->type.u.array.length);
2253 break;
2254 }
2255 case atype_sequence:
2256 case atype_sequence_bitfield:
2257 {
2258 const struct lttng_basic_type *elem_type;
2259 const struct lttng_basic_type *length_type;
2260
2261 elem_type = &field->type.u.sequence.elem_type;
2262 length_type = &field->type.u.sequence.length_type;
2263 ret = print_tabs(session, nesting);
2264 if (ret)
2265 return ret;
2266 ret = lttng_metadata_printf(session,
2267 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
2268 length_type->u.basic.integer.size,
2269 (unsigned int) length_type->u.basic.integer.alignment,
2270 length_type->u.basic.integer.signedness,
2271 (length_type->u.basic.integer.encoding == lttng_encode_none)
2272 ? "none"
2273 : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8)
2274 ? "UTF8"
2275 : "ASCII"),
2276 length_type->u.basic.integer.base,
2277 #if __BYTE_ORDER == __BIG_ENDIAN
2278 length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2279 #else
2280 length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2281 #endif
2282 field->name);
2283 if (ret)
2284 return ret;
2285
2286 if (field->type.u.sequence.elem_alignment) {
2287 ret = print_tabs(session, nesting);
2288 if (ret)
2289 return ret;
2290 ret = lttng_metadata_printf(session,
2291 "struct { } align(%u) _%s_padding;\n",
2292 field->type.u.sequence.elem_alignment * CHAR_BIT,
2293 field->name);
2294 if (ret)
2295 return ret;
2296 }
2297 ret = print_tabs(session, nesting);
2298 if (ret)
2299 return ret;
2300 ret = lttng_metadata_printf(session,
2301 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
2302 elem_type->u.basic.integer.size,
2303 (unsigned int) elem_type->u.basic.integer.alignment,
2304 elem_type->u.basic.integer.signedness,
2305 (elem_type->u.basic.integer.encoding == lttng_encode_none)
2306 ? "none"
2307 : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
2308 ? "UTF8"
2309 : "ASCII"),
2310 elem_type->u.basic.integer.base,
2311 #if __BYTE_ORDER == __BIG_ENDIAN
2312 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2313 #else
2314 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2315 #endif
2316 field->name,
2317 field->name);
2318 break;
2319 }
2320
2321 case atype_string:
2322 /* Default encoding is UTF8 */
2323 ret = print_tabs(session, nesting);
2324 if (ret)
2325 return ret;
2326 ret = lttng_metadata_printf(session,
2327 "string%s _%s;\n",
2328 field->type.u.basic.string.encoding == lttng_encode_ASCII ?
2329 " { encoding = ASCII; }" : "",
2330 field->name);
2331 break;
2332 case atype_struct:
2333 ret = _lttng_struct_statedump(session, field, nesting);
2334 break;
2335 case atype_array_compound:
2336 ret = _lttng_array_compound_statedump(session, field, nesting);
2337 break;
2338 case atype_sequence_compound:
2339 ret = _lttng_sequence_compound_statedump(session, field, nesting);
2340 break;
2341 case atype_variant:
2342 ret = _lttng_variant_statedump(session, field, nesting);
2343 break;
2344
2345 default:
2346 WARN_ON_ONCE(1);
2347 return -EINVAL;
2348 }
2349 return ret;
2350 }
2351
2352 static
2353 int _lttng_context_metadata_statedump(struct lttng_session *session,
2354 struct lttng_ctx *ctx)
2355 {
2356 int ret = 0;
2357 int i;
2358
2359 if (!ctx)
2360 return 0;
2361 for (i = 0; i < ctx->nr_fields; i++) {
2362 const struct lttng_ctx_field *field = &ctx->fields[i];
2363
2364 ret = _lttng_field_statedump(session, &field->event_field, 2);
2365 if (ret)
2366 return ret;
2367 }
2368 return ret;
2369 }
2370
2371 static
2372 int _lttng_fields_metadata_statedump(struct lttng_session *session,
2373 struct lttng_event *event)
2374 {
2375 const struct lttng_event_desc *desc = event->desc;
2376 int ret = 0;
2377 int i;
2378
2379 for (i = 0; i < desc->nr_fields; i++) {
2380 const struct lttng_event_field *field = &desc->fields[i];
2381
2382 ret = _lttng_field_statedump(session, field, 2);
2383 if (ret)
2384 return ret;
2385 }
2386 return ret;
2387 }
2388
2389 /*
2390 * Must be called with sessions_mutex held.
2391 * The entire event metadata is printed as a single atomic metadata
2392 * transaction.
2393 */
2394 static
2395 int _lttng_event_metadata_statedump(struct lttng_session *session,
2396 struct lttng_channel *chan,
2397 struct lttng_event *event)
2398 {
2399 int ret = 0;
2400
2401 if (event->metadata_dumped || !LTTNG_READ_ONCE(session->active))
2402 return 0;
2403 if (chan->channel_type == METADATA_CHANNEL)
2404 return 0;
2405
2406 lttng_metadata_begin(session);
2407
2408 ret = lttng_metadata_printf(session,
2409 "event {\n"
2410 " name = \"%s\";\n"
2411 " id = %u;\n"
2412 " stream_id = %u;\n",
2413 event->desc->name,
2414 event->id,
2415 event->chan->id);
2416 if (ret)
2417 goto end;
2418
2419 if (event->ctx) {
2420 ret = lttng_metadata_printf(session,
2421 " context := struct {\n");
2422 if (ret)
2423 goto end;
2424 }
2425 ret = _lttng_context_metadata_statedump(session, event->ctx);
2426 if (ret)
2427 goto end;
2428 if (event->ctx) {
2429 ret = lttng_metadata_printf(session,
2430 " };\n");
2431 if (ret)
2432 goto end;
2433 }
2434
2435 ret = lttng_metadata_printf(session,
2436 " fields := struct {\n"
2437 );
2438 if (ret)
2439 goto end;
2440
2441 ret = _lttng_fields_metadata_statedump(session, event);
2442 if (ret)
2443 goto end;
2444
2445 /*
2446 * LTTng space reservation can only reserve multiples of the
2447 * byte size.
2448 */
2449 ret = lttng_metadata_printf(session,
2450 " };\n"
2451 "};\n\n");
2452 if (ret)
2453 goto end;
2454
2455 event->metadata_dumped = 1;
2456 end:
2457 lttng_metadata_end(session);
2458 return ret;
2459
2460 }
2461
2462 /*
2463 * Must be called with sessions_mutex held.
2464 * The entire channel metadata is printed as a single atomic metadata
2465 * transaction.
2466 */
2467 static
2468 int _lttng_channel_metadata_statedump(struct lttng_session *session,
2469 struct lttng_channel *chan)
2470 {
2471 int ret = 0;
2472
2473 if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
2474 return 0;
2475
2476 if (chan->channel_type == METADATA_CHANNEL)
2477 return 0;
2478
2479 lttng_metadata_begin(session);
2480
2481 WARN_ON_ONCE(!chan->header_type);
2482 ret = lttng_metadata_printf(session,
2483 "stream {\n"
2484 " id = %u;\n"
2485 " event.header := %s;\n"
2486 " packet.context := struct packet_context;\n",
2487 chan->id,
2488 chan->header_type == 1 ? "struct event_header_compact" :
2489 "struct event_header_large");
2490 if (ret)
2491 goto end;
2492
2493 if (chan->ctx) {
2494 ret = lttng_metadata_printf(session,
2495 " event.context := struct {\n");
2496 if (ret)
2497 goto end;
2498 }
2499 ret = _lttng_context_metadata_statedump(session, chan->ctx);
2500 if (ret)
2501 goto end;
2502 if (chan->ctx) {
2503 ret = lttng_metadata_printf(session,
2504 " };\n");
2505 if (ret)
2506 goto end;
2507 }
2508
2509 ret = lttng_metadata_printf(session,
2510 "};\n\n");
2511
2512 chan->metadata_dumped = 1;
2513 end:
2514 lttng_metadata_end(session);
2515 return ret;
2516 }
2517
2518 /*
2519 * Must be called with sessions_mutex held.
2520 */
2521 static
2522 int _lttng_stream_packet_context_declare(struct lttng_session *session)
2523 {
2524 return lttng_metadata_printf(session,
2525 "struct packet_context {\n"
2526 " uint64_clock_monotonic_t timestamp_begin;\n"
2527 " uint64_clock_monotonic_t timestamp_end;\n"
2528 " uint64_t content_size;\n"
2529 " uint64_t packet_size;\n"
2530 " uint64_t packet_seq_num;\n"
2531 " unsigned long events_discarded;\n"
2532 " uint32_t cpu_id;\n"
2533 "};\n\n"
2534 );
2535 }
2536
2537 /*
2538 * Compact header:
2539 * id: range: 0 - 30.
2540 * id 31 is reserved to indicate an extended header.
2541 *
2542 * Large header:
2543 * id: range: 0 - 65534.
2544 * id 65535 is reserved to indicate an extended header.
2545 *
2546 * Must be called with sessions_mutex held.
2547 */
2548 static
2549 int _lttng_event_header_declare(struct lttng_session *session)
2550 {
2551 return lttng_metadata_printf(session,
2552 "struct event_header_compact {\n"
2553 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
2554 " variant <id> {\n"
2555 " struct {\n"
2556 " uint27_clock_monotonic_t timestamp;\n"
2557 " } compact;\n"
2558 " struct {\n"
2559 " uint32_t id;\n"
2560 " uint64_clock_monotonic_t timestamp;\n"
2561 " } extended;\n"
2562 " } v;\n"
2563 "} align(%u);\n"
2564 "\n"
2565 "struct event_header_large {\n"
2566 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
2567 " variant <id> {\n"
2568 " struct {\n"
2569 " uint32_clock_monotonic_t timestamp;\n"
2570 " } compact;\n"
2571 " struct {\n"
2572 " uint32_t id;\n"
2573 " uint64_clock_monotonic_t timestamp;\n"
2574 " } extended;\n"
2575 " } v;\n"
2576 "} align(%u);\n\n",
2577 lttng_alignof(uint32_t) * CHAR_BIT,
2578 lttng_alignof(uint16_t) * CHAR_BIT
2579 );
2580 }
2581
2582 /*
2583 * Approximation of NTP time of day to clock monotonic correlation,
2584 * taken at start of trace.
2585 * Yes, this is only an approximation. Yes, we can (and will) do better
2586 * in future versions.
2587 * This function may return a negative offset. It may happen if the
2588 * system sets the REALTIME clock to 0 after boot.
2589 *
2590 * Use 64bit timespec on kernels that have it, this makes 32bit arch
2591 * y2038 compliant.
2592 */
2593 static
2594 int64_t measure_clock_offset(void)
2595 {
2596 uint64_t monotonic_avg, monotonic[2], realtime;
2597 uint64_t tcf = trace_clock_freq();
2598 int64_t offset;
2599 unsigned long flags;
2600 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
2601 struct timespec64 rts = { 0, 0 };
2602 #else
2603 struct timespec rts = { 0, 0 };
2604 #endif
2605
2606 /* Disable interrupts to increase correlation precision. */
2607 local_irq_save(flags);
2608 monotonic[0] = trace_clock_read64();
2609 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
2610 ktime_get_real_ts64(&rts);
2611 #else
2612 getnstimeofday(&rts);
2613 #endif
2614 monotonic[1] = trace_clock_read64();
2615 local_irq_restore(flags);
2616
2617 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
2618 realtime = (uint64_t) rts.tv_sec * tcf;
2619 if (tcf == NSEC_PER_SEC) {
2620 realtime += rts.tv_nsec;
2621 } else {
2622 uint64_t n = rts.tv_nsec * tcf;
2623
2624 do_div(n, NSEC_PER_SEC);
2625 realtime += n;
2626 }
2627 offset = (int64_t) realtime - monotonic_avg;
2628 return offset;
2629 }
2630
2631 static
2632 int print_escaped_ctf_string(struct lttng_session *session, const char *string)
2633 {
2634 int ret = 0;
2635 size_t i;
2636 char cur;
2637
2638 i = 0;
2639 cur = string[i];
2640 while (cur != '\0') {
2641 switch (cur) {
2642 case '\n':
2643 ret = lttng_metadata_printf(session, "%s", "\\n");
2644 break;
2645 case '\\':
2646 case '"':
2647 ret = lttng_metadata_printf(session, "%c", '\\');
2648 if (ret)
2649 goto error;
2650 /* We still print the current char */
2651 /* Fallthrough */
2652 default:
2653 ret = lttng_metadata_printf(session, "%c", cur);
2654 break;
2655 }
2656
2657 if (ret)
2658 goto error;
2659
2660 cur = string[++i];
2661 }
2662 error:
2663 return ret;
2664 }
2665
2666 static
2667 int print_metadata_escaped_field(struct lttng_session *session, const char *field,
2668 const char *field_value)
2669 {
2670 int ret;
2671
2672 ret = lttng_metadata_printf(session, " %s = \"", field);
2673 if (ret)
2674 goto error;
2675
2676 ret = print_escaped_ctf_string(session, field_value);
2677 if (ret)
2678 goto error;
2679
2680 ret = lttng_metadata_printf(session, "\";\n");
2681
2682 error:
2683 return ret;
2684 }
2685
2686 /*
2687 * Output metadata into this session's metadata buffers.
2688 * Must be called with sessions_mutex held.
2689 */
2690 static
2691 int _lttng_session_metadata_statedump(struct lttng_session *session)
2692 {
2693 unsigned char *uuid_c = session->uuid.b;
2694 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
2695 const char *product_uuid;
2696 struct lttng_channel *chan;
2697 struct lttng_event *event;
2698 int ret = 0;
2699
2700 if (!LTTNG_READ_ONCE(session->active))
2701 return 0;
2702
2703 lttng_metadata_begin(session);
2704
2705 if (session->metadata_dumped)
2706 goto skip_session;
2707
2708 snprintf(uuid_s, sizeof(uuid_s),
2709 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
2710 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
2711 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
2712 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
2713 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
2714
2715 ret = lttng_metadata_printf(session,
2716 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
2717 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
2718 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
2719 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
2720 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
2721 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
2722 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
2723 "\n"
2724 "trace {\n"
2725 " major = %u;\n"
2726 " minor = %u;\n"
2727 " uuid = \"%s\";\n"
2728 " byte_order = %s;\n"
2729 " packet.header := struct {\n"
2730 " uint32_t magic;\n"
2731 " uint8_t uuid[16];\n"
2732 " uint32_t stream_id;\n"
2733 " uint64_t stream_instance_id;\n"
2734 " };\n"
2735 "};\n\n",
2736 lttng_alignof(uint8_t) * CHAR_BIT,
2737 lttng_alignof(uint16_t) * CHAR_BIT,
2738 lttng_alignof(uint32_t) * CHAR_BIT,
2739 lttng_alignof(uint64_t) * CHAR_BIT,
2740 sizeof(unsigned long) * CHAR_BIT,
2741 lttng_alignof(unsigned long) * CHAR_BIT,
2742 CTF_SPEC_MAJOR,
2743 CTF_SPEC_MINOR,
2744 uuid_s,
2745 #if __BYTE_ORDER == __BIG_ENDIAN
2746 "be"
2747 #else
2748 "le"
2749 #endif
2750 );
2751 if (ret)
2752 goto end;
2753
2754 ret = lttng_metadata_printf(session,
2755 "env {\n"
2756 " hostname = \"%s\";\n"
2757 " domain = \"kernel\";\n"
2758 " sysname = \"%s\";\n"
2759 " kernel_release = \"%s\";\n"
2760 " kernel_version = \"%s\";\n"
2761 " tracer_name = \"lttng-modules\";\n"
2762 " tracer_major = %d;\n"
2763 " tracer_minor = %d;\n"
2764 " tracer_patchlevel = %d;\n"
2765 " trace_buffering_scheme = \"global\";\n",
2766 current->nsproxy->uts_ns->name.nodename,
2767 utsname()->sysname,
2768 utsname()->release,
2769 utsname()->version,
2770 LTTNG_MODULES_MAJOR_VERSION,
2771 LTTNG_MODULES_MINOR_VERSION,
2772 LTTNG_MODULES_PATCHLEVEL_VERSION
2773 );
2774 if (ret)
2775 goto end;
2776
2777 ret = print_metadata_escaped_field(session, "trace_name", session->name);
2778 if (ret)
2779 goto end;
2780 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
2781 session->creation_time);
2782 if (ret)
2783 goto end;
2784
2785 /* Add the product UUID to the 'env' section */
2786 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
2787 if (product_uuid) {
2788 ret = lttng_metadata_printf(session,
2789 " product_uuid = \"%s\";\n",
2790 product_uuid
2791 );
2792 if (ret)
2793 goto end;
2794 }
2795
2796 /* Close the 'env' section */
2797 ret = lttng_metadata_printf(session, "};\n\n");
2798 if (ret)
2799 goto end;
2800
2801 ret = lttng_metadata_printf(session,
2802 "clock {\n"
2803 " name = \"%s\";\n",
2804 trace_clock_name()
2805 );
2806 if (ret)
2807 goto end;
2808
2809 if (!trace_clock_uuid(clock_uuid_s)) {
2810 ret = lttng_metadata_printf(session,
2811 " uuid = \"%s\";\n",
2812 clock_uuid_s
2813 );
2814 if (ret)
2815 goto end;
2816 }
2817
2818 ret = lttng_metadata_printf(session,
2819 " description = \"%s\";\n"
2820 " freq = %llu; /* Frequency, in Hz */\n"
2821 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
2822 " offset = %lld;\n"
2823 "};\n\n",
2824 trace_clock_description(),
2825 (unsigned long long) trace_clock_freq(),
2826 (long long) measure_clock_offset()
2827 );
2828 if (ret)
2829 goto end;
2830
2831 ret = lttng_metadata_printf(session,
2832 "typealias integer {\n"
2833 " size = 27; align = 1; signed = false;\n"
2834 " map = clock.%s.value;\n"
2835 "} := uint27_clock_monotonic_t;\n"
2836 "\n"
2837 "typealias integer {\n"
2838 " size = 32; align = %u; signed = false;\n"
2839 " map = clock.%s.value;\n"
2840 "} := uint32_clock_monotonic_t;\n"
2841 "\n"
2842 "typealias integer {\n"
2843 " size = 64; align = %u; signed = false;\n"
2844 " map = clock.%s.value;\n"
2845 "} := uint64_clock_monotonic_t;\n\n",
2846 trace_clock_name(),
2847 lttng_alignof(uint32_t) * CHAR_BIT,
2848 trace_clock_name(),
2849 lttng_alignof(uint64_t) * CHAR_BIT,
2850 trace_clock_name()
2851 );
2852 if (ret)
2853 goto end;
2854
2855 ret = _lttng_stream_packet_context_declare(session);
2856 if (ret)
2857 goto end;
2858
2859 ret = _lttng_event_header_declare(session);
2860 if (ret)
2861 goto end;
2862
2863 skip_session:
2864 list_for_each_entry(chan, &session->chan, list) {
2865 ret = _lttng_channel_metadata_statedump(session, chan);
2866 if (ret)
2867 goto end;
2868 }
2869
2870 list_for_each_entry(event, &session->events, list) {
2871 ret = _lttng_event_metadata_statedump(session, event->chan, event);
2872 if (ret)
2873 goto end;
2874 }
2875 session->metadata_dumped = 1;
2876 end:
2877 lttng_metadata_end(session);
2878 return ret;
2879 }
2880
2881 /**
2882 * lttng_transport_register - LTT transport registration
2883 * @transport: transport structure
2884 *
2885 * Registers a transport which can be used as output to extract the data out of
2886 * LTTng. The module calling this registration function must ensure that no
2887 * trap-inducing code will be executed by the transport functions. E.g.
2888 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
2889 * is made visible to the transport function. This registration acts as a
2890 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
2891 * after its registration must it synchronize the TLBs.
2892 */
2893 void lttng_transport_register(struct lttng_transport *transport)
2894 {
2895 /*
2896 * Make sure no page fault can be triggered by the module about to be
2897 * registered. We deal with this here so we don't have to call
2898 * vmalloc_sync_mappings() in each module's init.
2899 */
2900 wrapper_vmalloc_sync_mappings();
2901
2902 mutex_lock(&sessions_mutex);
2903 list_add_tail(&transport->node, &lttng_transport_list);
2904 mutex_unlock(&sessions_mutex);
2905 }
2906 EXPORT_SYMBOL_GPL(lttng_transport_register);
2907
2908 /**
2909 * lttng_transport_unregister - LTT transport unregistration
2910 * @transport: transport structure
2911 */
2912 void lttng_transport_unregister(struct lttng_transport *transport)
2913 {
2914 mutex_lock(&sessions_mutex);
2915 list_del(&transport->node);
2916 mutex_unlock(&sessions_mutex);
2917 }
2918 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
2919
2920 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
2921
2922 enum cpuhp_state lttng_hp_prepare;
2923 enum cpuhp_state lttng_hp_online;
2924
2925 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
2926 {
2927 struct lttng_cpuhp_node *lttng_node;
2928
2929 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2930 switch (lttng_node->component) {
2931 case LTTNG_RING_BUFFER_FRONTEND:
2932 return 0;
2933 case LTTNG_RING_BUFFER_BACKEND:
2934 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
2935 case LTTNG_RING_BUFFER_ITER:
2936 return 0;
2937 case LTTNG_CONTEXT_PERF_COUNTERS:
2938 return 0;
2939 default:
2940 return -EINVAL;
2941 }
2942 }
2943
2944 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
2945 {
2946 struct lttng_cpuhp_node *lttng_node;
2947
2948 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2949 switch (lttng_node->component) {
2950 case LTTNG_RING_BUFFER_FRONTEND:
2951 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
2952 case LTTNG_RING_BUFFER_BACKEND:
2953 return 0;
2954 case LTTNG_RING_BUFFER_ITER:
2955 return 0;
2956 case LTTNG_CONTEXT_PERF_COUNTERS:
2957 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
2958 default:
2959 return -EINVAL;
2960 }
2961 }
2962
2963 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
2964 {
2965 struct lttng_cpuhp_node *lttng_node;
2966
2967 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2968 switch (lttng_node->component) {
2969 case LTTNG_RING_BUFFER_FRONTEND:
2970 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
2971 case LTTNG_RING_BUFFER_BACKEND:
2972 return 0;
2973 case LTTNG_RING_BUFFER_ITER:
2974 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
2975 case LTTNG_CONTEXT_PERF_COUNTERS:
2976 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
2977 default:
2978 return -EINVAL;
2979 }
2980 }
2981
2982 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
2983 {
2984 struct lttng_cpuhp_node *lttng_node;
2985
2986 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2987 switch (lttng_node->component) {
2988 case LTTNG_RING_BUFFER_FRONTEND:
2989 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
2990 case LTTNG_RING_BUFFER_BACKEND:
2991 return 0;
2992 case LTTNG_RING_BUFFER_ITER:
2993 return 0;
2994 case LTTNG_CONTEXT_PERF_COUNTERS:
2995 return 0;
2996 default:
2997 return -EINVAL;
2998 }
2999 }
3000
3001 static int __init lttng_init_cpu_hotplug(void)
3002 {
3003 int ret;
3004
3005 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
3006 lttng_hotplug_prepare,
3007 lttng_hotplug_dead);
3008 if (ret < 0) {
3009 return ret;
3010 }
3011 lttng_hp_prepare = ret;
3012 lttng_rb_set_hp_prepare(ret);
3013
3014 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
3015 lttng_hotplug_online,
3016 lttng_hotplug_offline);
3017 if (ret < 0) {
3018 cpuhp_remove_multi_state(lttng_hp_prepare);
3019 lttng_hp_prepare = 0;
3020 return ret;
3021 }
3022 lttng_hp_online = ret;
3023 lttng_rb_set_hp_online(ret);
3024
3025 return 0;
3026 }
3027
3028 static void __exit lttng_exit_cpu_hotplug(void)
3029 {
3030 lttng_rb_set_hp_online(0);
3031 cpuhp_remove_multi_state(lttng_hp_online);
3032 lttng_rb_set_hp_prepare(0);
3033 cpuhp_remove_multi_state(lttng_hp_prepare);
3034 }
3035
3036 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
3037 static int lttng_init_cpu_hotplug(void)
3038 {
3039 return 0;
3040 }
3041 static void lttng_exit_cpu_hotplug(void)
3042 {
3043 }
3044 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
3045
3046
3047 static int __init lttng_events_init(void)
3048 {
3049 int ret;
3050
3051 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
3052 if (ret)
3053 return ret;
3054 ret = wrapper_get_pfnblock_flags_mask_init();
3055 if (ret)
3056 return ret;
3057 ret = wrapper_get_pageblock_flags_mask_init();
3058 if (ret)
3059 return ret;
3060 ret = lttng_probes_init();
3061 if (ret)
3062 return ret;
3063 ret = lttng_context_init();
3064 if (ret)
3065 return ret;
3066 ret = lttng_tracepoint_init();
3067 if (ret)
3068 goto error_tp;
3069 event_cache = KMEM_CACHE(lttng_event, 0);
3070 if (!event_cache) {
3071 ret = -ENOMEM;
3072 goto error_kmem;
3073 }
3074 ret = lttng_abi_init();
3075 if (ret)
3076 goto error_abi;
3077 ret = lttng_logger_init();
3078 if (ret)
3079 goto error_logger;
3080 ret = lttng_init_cpu_hotplug();
3081 if (ret)
3082 goto error_hotplug;
3083 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
3084 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3085 __stringify(LTTNG_MODULES_MINOR_VERSION),
3086 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3087 LTTNG_MODULES_EXTRAVERSION,
3088 LTTNG_VERSION_NAME,
3089 #ifdef LTTNG_EXTRA_VERSION_GIT
3090 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3091 #else
3092 "",
3093 #endif
3094 #ifdef LTTNG_EXTRA_VERSION_NAME
3095 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3096 #else
3097 "");
3098 #endif
3099 return 0;
3100
3101 error_hotplug:
3102 lttng_logger_exit();
3103 error_logger:
3104 lttng_abi_exit();
3105 error_abi:
3106 kmem_cache_destroy(event_cache);
3107 error_kmem:
3108 lttng_tracepoint_exit();
3109 error_tp:
3110 lttng_context_exit();
3111 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
3112 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3113 __stringify(LTTNG_MODULES_MINOR_VERSION),
3114 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3115 LTTNG_MODULES_EXTRAVERSION,
3116 LTTNG_VERSION_NAME,
3117 #ifdef LTTNG_EXTRA_VERSION_GIT
3118 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3119 #else
3120 "",
3121 #endif
3122 #ifdef LTTNG_EXTRA_VERSION_NAME
3123 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3124 #else
3125 "");
3126 #endif
3127 return ret;
3128 }
3129
3130 module_init(lttng_events_init);
3131
3132 static void __exit lttng_events_exit(void)
3133 {
3134 struct lttng_session *session, *tmpsession;
3135
3136 lttng_exit_cpu_hotplug();
3137 lttng_logger_exit();
3138 lttng_abi_exit();
3139 list_for_each_entry_safe(session, tmpsession, &sessions, list)
3140 lttng_session_destroy(session);
3141 kmem_cache_destroy(event_cache);
3142 lttng_tracepoint_exit();
3143 lttng_context_exit();
3144 printk(KERN_NOTICE "LTTng: Unloaded 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 }
3161
3162 module_exit(lttng_events_exit);
3163
3164 #include "extra_version/patches.i"
3165 #ifdef LTTNG_EXTRA_VERSION_GIT
3166 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
3167 #endif
3168 #ifdef LTTNG_EXTRA_VERSION_NAME
3169 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
3170 #endif
3171 MODULE_LICENSE("GPL and additional rights");
3172 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
3173 MODULE_DESCRIPTION("LTTng tracer");
3174 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
3175 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
3176 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
3177 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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