projects / lttng-modules.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Fix: filter interpreter early-exits on uninitialized value
[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 /*
708 * Populate lttng_event structure before kretprobe registration.
709 */
710 smp_wmb();
711 ret = lttng_kretprobes_register(event_name,
712 event_param->u.kretprobe.symbol_name,
713 event_param->u.kretprobe.offset,
714 event_param->u.kretprobe.addr,
715 event, event_return);
716 if (ret) {
717 kmem_cache_free(event_cache, event_return);
718 ret = -EINVAL;
719 goto register_error;
720 }
721 /* Take 2 refs on the module: one per event. */
722 ret = try_module_get(event->desc->owner);
723 WARN_ON_ONCE(!ret);
724 ret = try_module_get(event->desc->owner);
725 WARN_ON_ONCE(!ret);
726 ret = _lttng_event_metadata_statedump(chan->session, chan,
727 event_return);
728 WARN_ON_ONCE(ret > 0);
729 if (ret) {
730 kmem_cache_free(event_cache, event_return);
731 module_put(event->desc->owner);
732 module_put(event->desc->owner);
733 goto statedump_error;
734 }
735 list_add(&event_return->list, &chan->session->events);
736 break;
737 }
738 case LTTNG_KERNEL_NOOP:
739 case LTTNG_KERNEL_SYSCALL:
740 /*
741 * Needs to be explicitly enabled after creation, since
742 * we may want to apply filters.
743 */
744 event->enabled = 0;
745 event->registered = 0;
746 event->desc = event_desc;
747 switch (event_param->u.syscall.entryexit) {
748 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
749 ret = -EINVAL;
750 goto register_error;
751 case LTTNG_KERNEL_SYSCALL_ENTRY:
752 event->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
753 break;
754 case LTTNG_KERNEL_SYSCALL_EXIT:
755 event->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
756 break;
757 }
758 switch (event_param->u.syscall.abi) {
759 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
760 ret = -EINVAL;
761 goto register_error;
762 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
763 event->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
764 break;
765 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
766 event->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
767 break;
768 }
769 if (!event->desc) {
770 ret = -EINVAL;
771 goto register_error;
772 }
773 break;
774 case LTTNG_KERNEL_UPROBE:
775 /*
776 * Needs to be explicitly enabled after creation, since
777 * we may want to apply filters.
778 */
779 event->enabled = 0;
780 event->registered = 1;
781
782 /*
783 * Populate lttng_event structure before event
784 * registration.
785 */
786 smp_wmb();
787
788 ret = lttng_uprobes_register(event_param->name,
789 event_param->u.uprobe.fd,
790 event);
791 if (ret)
792 goto register_error;
793 ret = try_module_get(event->desc->owner);
794 WARN_ON_ONCE(!ret);
795 break;
796 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
797 default:
798 WARN_ON_ONCE(1);
799 ret = -EINVAL;
800 goto register_error;
801 }
802 ret = _lttng_event_metadata_statedump(chan->session, chan, event);
803 WARN_ON_ONCE(ret > 0);
804 if (ret) {
805 goto statedump_error;
806 }
807 hlist_add_head(&event->hlist, head);
808 list_add(&event->list, &chan->session->events);
809 return event;
810
811 statedump_error:
812 /* If a statedump error occurs, events will not be readable. */
813 register_error:
814 kmem_cache_free(event_cache, event);
815 cache_error:
816 exist:
817 type_error:
818 full:
819 return ERR_PTR(ret);
820 }
821
822 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
823 struct lttng_kernel_event *event_param,
824 void *filter,
825 const struct lttng_event_desc *event_desc,
826 enum lttng_kernel_instrumentation itype)
827 {
828 struct lttng_event *event;
829
830 mutex_lock(&sessions_mutex);
831 event = _lttng_event_create(chan, event_param, filter, event_desc,
832 itype);
833 mutex_unlock(&sessions_mutex);
834 return event;
835 }
836
837 /* Only used for tracepoints for now. */
838 static
839 void register_event(struct lttng_event *event)
840 {
841 const struct lttng_event_desc *desc;
842 int ret = -EINVAL;
843
844 if (event->registered)
845 return;
846
847 desc = event->desc;
848 switch (event->instrumentation) {
849 case LTTNG_KERNEL_TRACEPOINT:
850 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
851 desc->probe_callback,
852 event);
853 break;
854 case LTTNG_KERNEL_SYSCALL:
855 ret = lttng_syscall_filter_enable(event->chan, event);
856 break;
857 case LTTNG_KERNEL_KPROBE:
858 case LTTNG_KERNEL_UPROBE:
859 case LTTNG_KERNEL_KRETPROBE:
860 case LTTNG_KERNEL_NOOP:
861 ret = 0;
862 break;
863 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
864 default:
865 WARN_ON_ONCE(1);
866 }
867 if (!ret)
868 event->registered = 1;
869 }
870
871 /*
872 * Only used internally at session destruction.
873 */
874 int _lttng_event_unregister(struct lttng_event *event)
875 {
876 const struct lttng_event_desc *desc;
877 int ret = -EINVAL;
878
879 if (!event->registered)
880 return 0;
881
882 desc = event->desc;
883 switch (event->instrumentation) {
884 case LTTNG_KERNEL_TRACEPOINT:
885 ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname,
886 event->desc->probe_callback,
887 event);
888 break;
889 case LTTNG_KERNEL_KPROBE:
890 lttng_kprobes_unregister(event);
891 ret = 0;
892 break;
893 case LTTNG_KERNEL_KRETPROBE:
894 lttng_kretprobes_unregister(event);
895 ret = 0;
896 break;
897 case LTTNG_KERNEL_SYSCALL:
898 ret = lttng_syscall_filter_disable(event->chan, event);
899 break;
900 case LTTNG_KERNEL_NOOP:
901 ret = 0;
902 break;
903 case LTTNG_KERNEL_UPROBE:
904 lttng_uprobes_unregister(event);
905 ret = 0;
906 break;
907 case LTTNG_KERNEL_FUNCTION: /* Fall-through */
908 default:
909 WARN_ON_ONCE(1);
910 }
911 if (!ret)
912 event->registered = 0;
913 return ret;
914 }
915
916 /*
917 * Only used internally at session destruction.
918 */
919 static
920 void _lttng_event_destroy(struct lttng_event *event)
921 {
922 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
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 lttng_free_event_filter_runtime(event);
950 /* Free event enabler refs */
951 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
952 &event->enablers_ref_head, node)
953 kfree(enabler_ref);
954 kmem_cache_free(event_cache, event);
955 }
956
957 struct lttng_id_tracker *get_tracker(struct lttng_session *session,
958 enum tracker_type tracker_type)
959 {
960 switch (tracker_type) {
961 case TRACKER_PID:
962 return &session->pid_tracker;
963 case TRACKER_VPID:
964 return &session->vpid_tracker;
965 case TRACKER_UID:
966 return &session->uid_tracker;
967 case TRACKER_VUID:
968 return &session->vuid_tracker;
969 case TRACKER_GID:
970 return &session->gid_tracker;
971 case TRACKER_VGID:
972 return &session->vgid_tracker;
973 default:
974 WARN_ON_ONCE(1);
975 return NULL;
976 }
977 }
978
979 int lttng_session_track_id(struct lttng_session *session,
980 enum tracker_type tracker_type, int id)
981 {
982 struct lttng_id_tracker *tracker;
983 int ret;
984
985 tracker = get_tracker(session, tracker_type);
986 if (!tracker)
987 return -EINVAL;
988 if (id < -1)
989 return -EINVAL;
990 mutex_lock(&sessions_mutex);
991 if (id == -1) {
992 /* track all ids: destroy tracker. */
993 lttng_id_tracker_destroy(tracker, true);
994 ret = 0;
995 } else {
996 ret = lttng_id_tracker_add(tracker, id);
997 }
998 mutex_unlock(&sessions_mutex);
999 return ret;
1000 }
1001
1002 int lttng_session_untrack_id(struct lttng_session *session,
1003 enum tracker_type tracker_type, int id)
1004 {
1005 struct lttng_id_tracker *tracker;
1006 int ret;
1007
1008 tracker = get_tracker(session, tracker_type);
1009 if (!tracker)
1010 return -EINVAL;
1011 if (id < -1)
1012 return -EINVAL;
1013 mutex_lock(&sessions_mutex);
1014 if (id == -1) {
1015 /* untrack all ids: replace by empty tracker. */
1016 ret = lttng_id_tracker_empty_set(tracker);
1017 } else {
1018 ret = lttng_id_tracker_del(tracker, id);
1019 }
1020 mutex_unlock(&sessions_mutex);
1021 return ret;
1022 }
1023
1024 static
1025 void *id_list_start(struct seq_file *m, loff_t *pos)
1026 {
1027 struct lttng_id_tracker *id_tracker = m->private;
1028 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1029 struct lttng_id_hash_node *e;
1030 int iter = 0, i;
1031
1032 mutex_lock(&sessions_mutex);
1033 if (id_tracker_p) {
1034 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1035 struct hlist_head *head = &id_tracker_p->id_hash[i];
1036
1037 lttng_hlist_for_each_entry(e, head, hlist) {
1038 if (iter++ >= *pos)
1039 return e;
1040 }
1041 }
1042 } else {
1043 /* ID tracker disabled. */
1044 if (iter >= *pos && iter == 0) {
1045 return id_tracker_p; /* empty tracker */
1046 }
1047 iter++;
1048 }
1049 /* End of list */
1050 return NULL;
1051 }
1052
1053 /* Called with sessions_mutex held. */
1054 static
1055 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1056 {
1057 struct lttng_id_tracker *id_tracker = m->private;
1058 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1059 struct lttng_id_hash_node *e;
1060 int iter = 0, i;
1061
1062 (*ppos)++;
1063 if (id_tracker_p) {
1064 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1065 struct hlist_head *head = &id_tracker_p->id_hash[i];
1066
1067 lttng_hlist_for_each_entry(e, head, hlist) {
1068 if (iter++ >= *ppos)
1069 return e;
1070 }
1071 }
1072 } else {
1073 /* ID tracker disabled. */
1074 if (iter >= *ppos && iter == 0)
1075 return p; /* empty tracker */
1076 iter++;
1077 }
1078
1079 /* End of list */
1080 return NULL;
1081 }
1082
1083 static
1084 void id_list_stop(struct seq_file *m, void *p)
1085 {
1086 mutex_unlock(&sessions_mutex);
1087 }
1088
1089 static
1090 int id_list_show(struct seq_file *m, void *p)
1091 {
1092 struct lttng_id_tracker *id_tracker = m->private;
1093 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1094 int id;
1095
1096 if (p == id_tracker_p) {
1097 /* Tracker disabled. */
1098 id = -1;
1099 } else {
1100 const struct lttng_id_hash_node *e = p;
1101
1102 id = lttng_id_tracker_get_node_id(e);
1103 }
1104 switch (id_tracker->tracker_type) {
1105 case TRACKER_PID:
1106 seq_printf(m, "process { pid = %d; };\n", id);
1107 break;
1108 case TRACKER_VPID:
1109 seq_printf(m, "process { vpid = %d; };\n", id);
1110 break;
1111 case TRACKER_UID:
1112 seq_printf(m, "user { uid = %d; };\n", id);
1113 break;
1114 case TRACKER_VUID:
1115 seq_printf(m, "user { vuid = %d; };\n", id);
1116 break;
1117 case TRACKER_GID:
1118 seq_printf(m, "group { gid = %d; };\n", id);
1119 break;
1120 case TRACKER_VGID:
1121 seq_printf(m, "group { vgid = %d; };\n", id);
1122 break;
1123 default:
1124 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1125 }
1126 return 0;
1127 }
1128
1129 static
1130 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1131 .start = id_list_start,
1132 .next = id_list_next,
1133 .stop = id_list_stop,
1134 .show = id_list_show,
1135 };
1136
1137 static
1138 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1139 {
1140 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1141 }
1142
1143 static
1144 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1145 {
1146 struct seq_file *m = file->private_data;
1147 struct lttng_id_tracker *id_tracker = m->private;
1148 int ret;
1149
1150 WARN_ON_ONCE(!id_tracker);
1151 ret = seq_release(inode, file);
1152 if (!ret)
1153 fput(id_tracker->session->file);
1154 return ret;
1155 }
1156
1157 const struct file_operations lttng_tracker_ids_list_fops = {
1158 .owner = THIS_MODULE,
1159 .open = lttng_tracker_ids_list_open,
1160 .read = seq_read,
1161 .llseek = seq_lseek,
1162 .release = lttng_tracker_ids_list_release,
1163 };
1164
1165 int lttng_session_list_tracker_ids(struct lttng_session *session,
1166 enum tracker_type tracker_type)
1167 {
1168 struct file *tracker_ids_list_file;
1169 struct seq_file *m;
1170 int file_fd, ret;
1171
1172 file_fd = lttng_get_unused_fd();
1173 if (file_fd < 0) {
1174 ret = file_fd;
1175 goto fd_error;
1176 }
1177
1178 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1179 &lttng_tracker_ids_list_fops,
1180 NULL, O_RDWR);
1181 if (IS_ERR(tracker_ids_list_file)) {
1182 ret = PTR_ERR(tracker_ids_list_file);
1183 goto file_error;
1184 }
1185 if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
1186 ret = -EOVERFLOW;
1187 goto refcount_error;
1188 }
1189 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1190 if (ret < 0)
1191 goto open_error;
1192 m = tracker_ids_list_file->private_data;
1193
1194 m->private = get_tracker(session, tracker_type);
1195 BUG_ON(!m->private);
1196 fd_install(file_fd, tracker_ids_list_file);
1197
1198 return file_fd;
1199
1200 open_error:
1201 atomic_long_dec(&session->file->f_count);
1202 refcount_error:
1203 fput(tracker_ids_list_file);
1204 file_error:
1205 put_unused_fd(file_fd);
1206 fd_error:
1207 return ret;
1208 }
1209
1210 /*
1211 * Enabler management.
1212 */
1213 static
1214 int lttng_match_enabler_star_glob(const char *desc_name,
1215 const char *pattern)
1216 {
1217 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1218 desc_name, LTTNG_SIZE_MAX))
1219 return 0;
1220 return 1;
1221 }
1222
1223 static
1224 int lttng_match_enabler_name(const char *desc_name,
1225 const char *name)
1226 {
1227 if (strcmp(desc_name, name))
1228 return 0;
1229 return 1;
1230 }
1231
1232 static
1233 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
1234 struct lttng_enabler *enabler)
1235 {
1236 const char *desc_name, *enabler_name;
1237 bool compat = false, entry = false;
1238
1239 enabler_name = enabler->event_param.name;
1240 switch (enabler->event_param.instrumentation) {
1241 case LTTNG_KERNEL_TRACEPOINT:
1242 desc_name = desc->name;
1243 switch (enabler->type) {
1244 case LTTNG_ENABLER_STAR_GLOB:
1245 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1246 case LTTNG_ENABLER_NAME:
1247 return lttng_match_enabler_name(desc_name, enabler_name);
1248 default:
1249 return -EINVAL;
1250 }
1251 break;
1252 case LTTNG_KERNEL_SYSCALL:
1253 desc_name = desc->name;
1254 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1255 desc_name += strlen("compat_");
1256 compat = true;
1257 }
1258 if (!strncmp(desc_name, "syscall_exit_",
1259 strlen("syscall_exit_"))) {
1260 desc_name += strlen("syscall_exit_");
1261 } else if (!strncmp(desc_name, "syscall_entry_",
1262 strlen("syscall_entry_"))) {
1263 desc_name += strlen("syscall_entry_");
1264 entry = true;
1265 } else {
1266 WARN_ON_ONCE(1);
1267 return -EINVAL;
1268 }
1269 switch (enabler->event_param.u.syscall.entryexit) {
1270 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1271 break;
1272 case LTTNG_KERNEL_SYSCALL_ENTRY:
1273 if (!entry)
1274 return 0;
1275 break;
1276 case LTTNG_KERNEL_SYSCALL_EXIT:
1277 if (entry)
1278 return 0;
1279 break;
1280 default:
1281 return -EINVAL;
1282 }
1283 switch (enabler->event_param.u.syscall.abi) {
1284 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1285 break;
1286 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1287 if (compat)
1288 return 0;
1289 break;
1290 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1291 if (!compat)
1292 return 0;
1293 break;
1294 default:
1295 return -EINVAL;
1296 }
1297 switch (enabler->event_param.u.syscall.match) {
1298 case LTTNG_SYSCALL_MATCH_NAME:
1299 switch (enabler->type) {
1300 case LTTNG_ENABLER_STAR_GLOB:
1301 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1302 case LTTNG_ENABLER_NAME:
1303 return lttng_match_enabler_name(desc_name, enabler_name);
1304 default:
1305 return -EINVAL;
1306 }
1307 break;
1308 case LTTNG_SYSCALL_MATCH_NR:
1309 return -EINVAL; /* Not implemented. */
1310 default:
1311 return -EINVAL;
1312 }
1313 break;
1314 default:
1315 WARN_ON_ONCE(1);
1316 return -EINVAL;
1317 }
1318 }
1319
1320 static
1321 int lttng_event_match_enabler(struct lttng_event *event,
1322 struct lttng_enabler *enabler)
1323 {
1324 if (enabler->event_param.instrumentation != event->instrumentation)
1325 return 0;
1326 if (lttng_desc_match_enabler(event->desc, enabler)
1327 && event->chan == enabler->chan)
1328 return 1;
1329 else
1330 return 0;
1331 }
1332
1333 static
1334 struct lttng_enabler_ref *lttng_event_enabler_ref(struct lttng_event *event,
1335 struct lttng_enabler *enabler)
1336 {
1337 struct lttng_enabler_ref *enabler_ref;
1338
1339 list_for_each_entry(enabler_ref,
1340 &event->enablers_ref_head, node) {
1341 if (enabler_ref->ref == enabler)
1342 return enabler_ref;
1343 }
1344 return NULL;
1345 }
1346
1347 static
1348 void lttng_create_tracepoint_if_missing(struct lttng_enabler *enabler)
1349 {
1350 struct lttng_session *session = enabler->chan->session;
1351 struct lttng_probe_desc *probe_desc;
1352 const struct lttng_event_desc *desc;
1353 int i;
1354 struct list_head *probe_list;
1355
1356 probe_list = lttng_get_probe_list_head();
1357 /*
1358 * For each probe event, if we find that a probe event matches
1359 * our enabler, create an associated lttng_event if not
1360 * already present.
1361 */
1362 list_for_each_entry(probe_desc, probe_list, head) {
1363 for (i = 0; i < probe_desc->nr_events; i++) {
1364 int found = 0;
1365 struct hlist_head *head;
1366 const char *event_name;
1367 size_t name_len;
1368 uint32_t hash;
1369 struct lttng_event *event;
1370
1371 desc = probe_desc->event_desc[i];
1372 if (!lttng_desc_match_enabler(desc, enabler))
1373 continue;
1374 event_name = desc->name;
1375 name_len = strlen(event_name);
1376
1377 /*
1378 * Check if already created.
1379 */
1380 hash = jhash(event_name, name_len, 0);
1381 head = &session->events_ht.table[hash & (LTTNG_EVENT_HT_SIZE - 1)];
1382 lttng_hlist_for_each_entry(event, head, hlist) {
1383 if (event->desc == desc
1384 && event->chan == enabler->chan)
1385 found = 1;
1386 }
1387 if (found)
1388 continue;
1389
1390 /*
1391 * We need to create an event for this
1392 * event probe.
1393 */
1394 event = _lttng_event_create(enabler->chan,
1395 NULL, NULL, desc,
1396 LTTNG_KERNEL_TRACEPOINT);
1397 if (!event) {
1398 printk(KERN_INFO "Unable to create event %s\n",
1399 probe_desc->event_desc[i]->name);
1400 }
1401 }
1402 }
1403 }
1404
1405 static
1406 void lttng_create_syscall_if_missing(struct lttng_enabler *enabler)
1407 {
1408 int ret;
1409
1410 ret = lttng_syscalls_register(enabler->chan, NULL);
1411 WARN_ON_ONCE(ret);
1412 }
1413
1414 /*
1415 * Create struct lttng_event if it is missing and present in the list of
1416 * tracepoint probes.
1417 * Should be called with sessions mutex held.
1418 */
1419 static
1420 void lttng_create_event_if_missing(struct lttng_enabler *enabler)
1421 {
1422 switch (enabler->event_param.instrumentation) {
1423 case LTTNG_KERNEL_TRACEPOINT:
1424 lttng_create_tracepoint_if_missing(enabler);
1425 break;
1426 case LTTNG_KERNEL_SYSCALL:
1427 lttng_create_syscall_if_missing(enabler);
1428 break;
1429 default:
1430 WARN_ON_ONCE(1);
1431 break;
1432 }
1433 }
1434
1435 /*
1436 * Create events associated with an enabler (if not already present),
1437 * and add backward reference from the event to the enabler.
1438 * Should be called with sessions mutex held.
1439 */
1440 static
1441 int lttng_enabler_ref_events(struct lttng_enabler *enabler)
1442 {
1443 struct lttng_channel *chan = enabler->chan;
1444 struct lttng_session *session = chan->session;
1445 struct lttng_event *event;
1446
1447 if (enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
1448 enabler->event_param.u.syscall.entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT &&
1449 enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
1450 enabler->event_param.u.syscall.match == LTTNG_SYSCALL_MATCH_NAME &&
1451 !strcmp(enabler->event_param.name, "*")) {
1452 if (enabler->enabled)
1453 WRITE_ONCE(chan->syscall_all, 1);
1454 else
1455 WRITE_ONCE(chan->syscall_all, 0);
1456 }
1457
1458 /* First ensure that probe events are created for this enabler. */
1459 lttng_create_event_if_missing(enabler);
1460
1461 /* For each event matching enabler in session event list. */
1462 list_for_each_entry(event, &session->events, list) {
1463 struct lttng_enabler_ref *enabler_ref;
1464
1465 if (!lttng_event_match_enabler(event, enabler))
1466 continue;
1467 enabler_ref = lttng_event_enabler_ref(event, enabler);
1468 if (!enabler_ref) {
1469 /*
1470 * If no backward ref, create it.
1471 * Add backward ref from event to enabler.
1472 */
1473 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
1474 if (!enabler_ref)
1475 return -ENOMEM;
1476 enabler_ref->ref = enabler;
1477 list_add(&enabler_ref->node,
1478 &event->enablers_ref_head);
1479 }
1480
1481 /*
1482 * Link filter bytecodes if not linked yet.
1483 */
1484 lttng_enabler_event_link_bytecode(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_enablers(session);
1502 return 0;
1503 }
1504
1505 struct lttng_enabler *lttng_enabler_create(enum lttng_enabler_type type,
1506 struct lttng_kernel_event *event_param,
1507 struct lttng_channel *chan)
1508 {
1509 struct lttng_enabler *enabler;
1510
1511 enabler = kzalloc(sizeof(*enabler), GFP_KERNEL);
1512 if (!enabler)
1513 return NULL;
1514 enabler->type = type;
1515 INIT_LIST_HEAD(&enabler->filter_bytecode_head);
1516 memcpy(&enabler->event_param, event_param,
1517 sizeof(enabler->event_param));
1518 enabler->chan = chan;
1519 /* ctx left NULL */
1520 enabler->enabled = 0;
1521 enabler->evtype = LTTNG_TYPE_ENABLER;
1522 mutex_lock(&sessions_mutex);
1523 list_add(&enabler->node, &enabler->chan->session->enablers_head);
1524 lttng_session_lazy_sync_enablers(enabler->chan->session);
1525 mutex_unlock(&sessions_mutex);
1526 return enabler;
1527 }
1528
1529 int lttng_enabler_enable(struct lttng_enabler *enabler)
1530 {
1531 mutex_lock(&sessions_mutex);
1532 enabler->enabled = 1;
1533 lttng_session_lazy_sync_enablers(enabler->chan->session);
1534 mutex_unlock(&sessions_mutex);
1535 return 0;
1536 }
1537
1538 int lttng_enabler_disable(struct lttng_enabler *enabler)
1539 {
1540 mutex_lock(&sessions_mutex);
1541 enabler->enabled = 0;
1542 lttng_session_lazy_sync_enablers(enabler->chan->session);
1543 mutex_unlock(&sessions_mutex);
1544 return 0;
1545 }
1546
1547 int lttng_enabler_attach_bytecode(struct lttng_enabler *enabler,
1548 struct lttng_kernel_filter_bytecode __user *bytecode)
1549 {
1550 struct lttng_filter_bytecode_node *bytecode_node;
1551 uint32_t bytecode_len;
1552 int ret;
1553
1554 ret = get_user(bytecode_len, &bytecode->len);
1555 if (ret)
1556 return ret;
1557 bytecode_node = kzalloc(sizeof(*bytecode_node) + bytecode_len,
1558 GFP_KERNEL);
1559 if (!bytecode_node)
1560 return -ENOMEM;
1561 ret = copy_from_user(&bytecode_node->bc, bytecode,
1562 sizeof(*bytecode) + bytecode_len);
1563 if (ret)
1564 goto error_free;
1565 bytecode_node->enabler = enabler;
1566 /* Enforce length based on allocated size */
1567 bytecode_node->bc.len = bytecode_len;
1568 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
1569 lttng_session_lazy_sync_enablers(enabler->chan->session);
1570 return 0;
1571
1572 error_free:
1573 kfree(bytecode_node);
1574 return ret;
1575 }
1576
1577 int lttng_event_add_callsite(struct lttng_event *event,
1578 struct lttng_kernel_event_callsite __user *callsite)
1579 {
1580
1581 switch (event->instrumentation) {
1582 case LTTNG_KERNEL_UPROBE:
1583 return lttng_uprobes_add_callsite(event, callsite);
1584 default:
1585 return -EINVAL;
1586 }
1587 }
1588
1589 int lttng_enabler_attach_context(struct lttng_enabler *enabler,
1590 struct lttng_kernel_context *context_param)
1591 {
1592 return -ENOSYS;
1593 }
1594
1595 static
1596 void lttng_enabler_destroy(struct lttng_enabler *enabler)
1597 {
1598 struct lttng_filter_bytecode_node *filter_node, *tmp_filter_node;
1599
1600 /* Destroy filter bytecode */
1601 list_for_each_entry_safe(filter_node, tmp_filter_node,
1602 &enabler->filter_bytecode_head, node) {
1603 kfree(filter_node);
1604 }
1605
1606 /* Destroy contexts */
1607 lttng_destroy_context(enabler->ctx);
1608
1609 list_del(&enabler->node);
1610 kfree(enabler);
1611 }
1612
1613 /*
1614 * lttng_session_sync_enablers should be called just before starting a
1615 * session.
1616 * Should be called with sessions mutex held.
1617 */
1618 static
1619 void lttng_session_sync_enablers(struct lttng_session *session)
1620 {
1621 struct lttng_enabler *enabler;
1622 struct lttng_event *event;
1623
1624 list_for_each_entry(enabler, &session->enablers_head, node)
1625 lttng_enabler_ref_events(enabler);
1626 /*
1627 * For each event, if at least one of its enablers is enabled,
1628 * and its channel and session transient states are enabled, we
1629 * enable the event, else we disable it.
1630 */
1631 list_for_each_entry(event, &session->events, list) {
1632 struct lttng_enabler_ref *enabler_ref;
1633 struct lttng_bytecode_runtime *runtime;
1634 int enabled = 0, has_enablers_without_bytecode = 0;
1635
1636 switch (event->instrumentation) {
1637 case LTTNG_KERNEL_TRACEPOINT:
1638 case LTTNG_KERNEL_SYSCALL:
1639 /* Enable events */
1640 list_for_each_entry(enabler_ref,
1641 &event->enablers_ref_head, node) {
1642 if (enabler_ref->ref->enabled) {
1643 enabled = 1;
1644 break;
1645 }
1646 }
1647 break;
1648 default:
1649 /* Not handled with lazy sync. */
1650 continue;
1651 }
1652 /*
1653 * Enabled state is based on union of enablers, with
1654 * intesection of session and channel transient enable
1655 * states.
1656 */
1657 enabled = enabled && session->tstate && event->chan->tstate;
1658
1659 WRITE_ONCE(event->enabled, enabled);
1660 /*
1661 * Sync tracepoint registration with event enabled
1662 * state.
1663 */
1664 if (enabled) {
1665 register_event(event);
1666 } else {
1667 _lttng_event_unregister(event);
1668 }
1669
1670 /* Check if has enablers without bytecode enabled */
1671 list_for_each_entry(enabler_ref,
1672 &event->enablers_ref_head, node) {
1673 if (enabler_ref->ref->enabled
1674 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
1675 has_enablers_without_bytecode = 1;
1676 break;
1677 }
1678 }
1679 event->has_enablers_without_bytecode =
1680 has_enablers_without_bytecode;
1681
1682 /* Enable filters */
1683 list_for_each_entry(runtime,
1684 &event->bytecode_runtime_head, node)
1685 lttng_filter_sync_state(runtime);
1686 }
1687 }
1688
1689 /*
1690 * Apply enablers to session events, adding events to session if need
1691 * be. It is required after each modification applied to an active
1692 * session, and right before session "start".
1693 * "lazy" sync means we only sync if required.
1694 * Should be called with sessions mutex held.
1695 */
1696 static
1697 void lttng_session_lazy_sync_enablers(struct lttng_session *session)
1698 {
1699 /* We can skip if session is not active */
1700 if (!session->active)
1701 return;
1702 lttng_session_sync_enablers(session);
1703 }
1704
1705 /*
1706 * Serialize at most one packet worth of metadata into a metadata
1707 * channel.
1708 * We grab the metadata cache mutex to get exclusive access to our metadata
1709 * buffer and to the metadata cache. Exclusive access to the metadata buffer
1710 * allows us to do racy operations such as looking for remaining space left in
1711 * packet and write, since mutual exclusion protects us from concurrent writes.
1712 * Mutual exclusion on the metadata cache allow us to read the cache content
1713 * without racing against reallocation of the cache by updates.
1714 * Returns the number of bytes written in the channel, 0 if no data
1715 * was written and a negative value on error.
1716 */
1717 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
1718 struct channel *chan, bool *coherent)
1719 {
1720 struct lib_ring_buffer_ctx ctx;
1721 int ret = 0;
1722 size_t len, reserve_len;
1723
1724 /*
1725 * Ensure we support mutiple get_next / put sequences followed by
1726 * put_next. The metadata cache lock protects reading the metadata
1727 * cache. It can indeed be read concurrently by "get_next_subbuf" and
1728 * "flush" operations on the buffer invoked by different processes.
1729 * Moreover, since the metadata cache memory can be reallocated, we
1730 * need to have exclusive access against updates even though we only
1731 * read it.
1732 */
1733 mutex_lock(&stream->metadata_cache->lock);
1734 WARN_ON(stream->metadata_in < stream->metadata_out);
1735 if (stream->metadata_in != stream->metadata_out)
1736 goto end;
1737
1738 /* Metadata regenerated, change the version. */
1739 if (stream->metadata_cache->version != stream->version)
1740 stream->version = stream->metadata_cache->version;
1741
1742 len = stream->metadata_cache->metadata_written -
1743 stream->metadata_in;
1744 if (!len)
1745 goto end;
1746 reserve_len = min_t(size_t,
1747 stream->transport->ops.packet_avail_size(chan),
1748 len);
1749 lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
1750 sizeof(char), -1);
1751 /*
1752 * If reservation failed, return an error to the caller.
1753 */
1754 ret = stream->transport->ops.event_reserve(&ctx, 0);
1755 if (ret != 0) {
1756 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
1757 stream->coherent = false;
1758 goto end;
1759 }
1760 stream->transport->ops.event_write(&ctx,
1761 stream->metadata_cache->data + stream->metadata_in,
1762 reserve_len);
1763 stream->transport->ops.event_commit(&ctx);
1764 stream->metadata_in += reserve_len;
1765 if (reserve_len < len)
1766 stream->coherent = false;
1767 else
1768 stream->coherent = true;
1769 ret = reserve_len;
1770
1771 end:
1772 if (coherent)
1773 *coherent = stream->coherent;
1774 mutex_unlock(&stream->metadata_cache->lock);
1775 return ret;
1776 }
1777
1778 static
1779 void lttng_metadata_begin(struct lttng_session *session)
1780 {
1781 if (atomic_inc_return(&session->metadata_cache->producing) == 1)
1782 mutex_lock(&session->metadata_cache->lock);
1783 }
1784
1785 static
1786 void lttng_metadata_end(struct lttng_session *session)
1787 {
1788 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
1789 if (atomic_dec_return(&session->metadata_cache->producing) == 0) {
1790 struct lttng_metadata_stream *stream;
1791
1792 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
1793 wake_up_interruptible(&stream->read_wait);
1794 mutex_unlock(&session->metadata_cache->lock);
1795 }
1796 }
1797
1798 /*
1799 * Write the metadata to the metadata cache.
1800 * Must be called with sessions_mutex held.
1801 * The metadata cache lock protects us from concurrent read access from
1802 * thread outputting metadata content to ring buffer.
1803 * The content of the printf is printed as a single atomic metadata
1804 * transaction.
1805 */
1806 int lttng_metadata_printf(struct lttng_session *session,
1807 const char *fmt, ...)
1808 {
1809 char *str;
1810 size_t len;
1811 va_list ap;
1812
1813 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
1814
1815 va_start(ap, fmt);
1816 str = kvasprintf(GFP_KERNEL, fmt, ap);
1817 va_end(ap);
1818 if (!str)
1819 return -ENOMEM;
1820
1821 len = strlen(str);
1822 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
1823 if (session->metadata_cache->metadata_written + len >
1824 session->metadata_cache->cache_alloc) {
1825 char *tmp_cache_realloc;
1826 unsigned int tmp_cache_alloc_size;
1827
1828 tmp_cache_alloc_size = max_t(unsigned int,
1829 session->metadata_cache->cache_alloc + len,
1830 session->metadata_cache->cache_alloc << 1);
1831 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
1832 if (!tmp_cache_realloc)
1833 goto err;
1834 if (session->metadata_cache->data) {
1835 memcpy(tmp_cache_realloc,
1836 session->metadata_cache->data,
1837 session->metadata_cache->cache_alloc);
1838 vfree(session->metadata_cache->data);
1839 }
1840
1841 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
1842 session->metadata_cache->data = tmp_cache_realloc;
1843 }
1844 memcpy(session->metadata_cache->data +
1845 session->metadata_cache->metadata_written,
1846 str, len);
1847 session->metadata_cache->metadata_written += len;
1848 kfree(str);
1849
1850 return 0;
1851
1852 err:
1853 kfree(str);
1854 return -ENOMEM;
1855 }
1856
1857 static
1858 int print_tabs(struct lttng_session *session, size_t nesting)
1859 {
1860 size_t i;
1861
1862 for (i = 0; i < nesting; i++) {
1863 int ret;
1864
1865 ret = lttng_metadata_printf(session, " ");
1866 if (ret) {
1867 return ret;
1868 }
1869 }
1870 return 0;
1871 }
1872
1873 /*
1874 * Must be called with sessions_mutex held.
1875 */
1876 static
1877 int _lttng_struct_type_statedump(struct lttng_session *session,
1878 const struct lttng_type *type,
1879 size_t nesting)
1880 {
1881 int ret;
1882 uint32_t i, nr_fields;
1883
1884 ret = print_tabs(session, nesting);
1885 if (ret)
1886 return ret;
1887 ret = lttng_metadata_printf(session,
1888 "struct {\n");
1889 if (ret)
1890 return ret;
1891 nr_fields = type->u._struct.nr_fields;
1892 for (i = 0; i < nr_fields; i++) {
1893 const struct lttng_event_field *iter_field;
1894
1895 iter_field = &type->u._struct.fields[i];
1896 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
1897 if (ret)
1898 return ret;
1899 }
1900 ret = print_tabs(session, nesting);
1901 if (ret)
1902 return ret;
1903 ret = lttng_metadata_printf(session,
1904 "}");
1905 return ret;
1906 }
1907
1908 /*
1909 * Must be called with sessions_mutex held.
1910 */
1911 static
1912 int _lttng_struct_statedump(struct lttng_session *session,
1913 const struct lttng_event_field *field,
1914 size_t nesting)
1915 {
1916 int ret;
1917
1918 ret = _lttng_struct_type_statedump(session,
1919 &field->type, nesting);
1920 if (ret)
1921 return ret;
1922 ret = lttng_metadata_printf(session,
1923 "_%s;\n",
1924 field->name);
1925 return ret;
1926 }
1927
1928 /*
1929 * Must be called with sessions_mutex held.
1930 */
1931 static
1932 int _lttng_variant_type_statedump(struct lttng_session *session,
1933 const struct lttng_type *type,
1934 size_t nesting)
1935 {
1936 int ret;
1937 uint32_t i, nr_choices;
1938
1939 ret = print_tabs(session, nesting);
1940 if (ret)
1941 return ret;
1942 ret = lttng_metadata_printf(session,
1943 "variant <_%s> {\n",
1944 type->u.variant.tag_name);
1945 if (ret)
1946 return ret;
1947 nr_choices = type->u.variant.nr_choices;
1948 for (i = 0; i < nr_choices; i++) {
1949 const struct lttng_event_field *iter_field;
1950
1951 iter_field = &type->u.variant.choices[i];
1952 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
1953 if (ret)
1954 return ret;
1955 }
1956 ret = print_tabs(session, nesting);
1957 if (ret)
1958 return ret;
1959 ret = lttng_metadata_printf(session,
1960 "}");
1961 return ret;
1962 }
1963
1964 /*
1965 * Must be called with sessions_mutex held.
1966 */
1967 static
1968 int _lttng_variant_statedump(struct lttng_session *session,
1969 const struct lttng_event_field *field,
1970 size_t nesting)
1971 {
1972 int ret;
1973
1974 ret = _lttng_variant_type_statedump(session,
1975 &field->type, nesting);
1976 if (ret)
1977 return ret;
1978 ret = lttng_metadata_printf(session,
1979 "_%s;\n",
1980 field->name);
1981 return ret;
1982 }
1983
1984 /*
1985 * Must be called with sessions_mutex held.
1986 */
1987 static
1988 int _lttng_array_compound_statedump(struct lttng_session *session,
1989 const struct lttng_event_field *field,
1990 size_t nesting)
1991 {
1992 int ret;
1993 const struct lttng_type *elem_type;
1994
1995 /* Only array of structures and variants are currently supported. */
1996 elem_type = field->type.u.array_compound.elem_type;
1997 switch (elem_type->atype) {
1998 case atype_struct:
1999 ret = _lttng_struct_type_statedump(session, elem_type, nesting);
2000 if (ret)
2001 return ret;
2002 break;
2003 case atype_variant:
2004 ret = _lttng_variant_type_statedump(session, elem_type, nesting);
2005 if (ret)
2006 return ret;
2007 break;
2008 default:
2009 return -EINVAL;
2010 }
2011 ret = lttng_metadata_printf(session,
2012 " _%s[%u];\n",
2013 field->name,
2014 field->type.u.array_compound.length);
2015 return ret;
2016 }
2017
2018 /*
2019 * Must be called with sessions_mutex held.
2020 */
2021 static
2022 int _lttng_sequence_compound_statedump(struct lttng_session *session,
2023 const struct lttng_event_field *field,
2024 size_t nesting)
2025 {
2026 int ret;
2027 const char *length_name;
2028 const struct lttng_type *elem_type;
2029
2030 length_name = field->type.u.sequence_compound.length_name;
2031
2032 /* Only array of structures and variants are currently supported. */
2033 elem_type = field->type.u.sequence_compound.elem_type;
2034 switch (elem_type->atype) {
2035 case atype_struct:
2036 ret = _lttng_struct_type_statedump(session, elem_type, nesting);
2037 if (ret)
2038 return ret;
2039 break;
2040 case atype_variant:
2041 ret = _lttng_variant_type_statedump(session, elem_type, nesting);
2042 if (ret)
2043 return ret;
2044 break;
2045 default:
2046 return -EINVAL;
2047 }
2048 ret = lttng_metadata_printf(session,
2049 " _%s[ _%s ];\n",
2050 field->name,
2051 length_name);
2052 return ret;
2053 }
2054
2055 /*
2056 * Must be called with sessions_mutex held.
2057 */
2058 static
2059 int _lttng_enum_statedump(struct lttng_session *session,
2060 const struct lttng_event_field *field,
2061 size_t nesting)
2062 {
2063 const struct lttng_enum_desc *enum_desc;
2064 const struct lttng_integer_type *container_type;
2065 int ret;
2066 unsigned int i, nr_entries;
2067
2068 enum_desc = field->type.u.basic.enumeration.desc;
2069 container_type = &field->type.u.basic.enumeration.container_type;
2070 nr_entries = enum_desc->nr_entries;
2071
2072 ret = print_tabs(session, nesting);
2073 if (ret)
2074 goto end;
2075 ret = lttng_metadata_printf(session,
2076 "enum : integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } {\n",
2077 container_type->size,
2078 container_type->alignment,
2079 container_type->signedness,
2080 (container_type->encoding == lttng_encode_none)
2081 ? "none"
2082 : (container_type->encoding == lttng_encode_UTF8)
2083 ? "UTF8"
2084 : "ASCII",
2085 container_type->base,
2086 #if __BYTE_ORDER == __BIG_ENDIAN
2087 container_type->reverse_byte_order ? " byte_order = le;" : ""
2088 #else
2089 container_type->reverse_byte_order ? " byte_order = be;" : ""
2090 #endif
2091 );
2092 if (ret)
2093 goto end;
2094 /* Dump all entries */
2095 for (i = 0; i < nr_entries; i++) {
2096 const struct lttng_enum_entry *entry = &enum_desc->entries[i];
2097 int j, len;
2098
2099 ret = print_tabs(session, nesting + 1);
2100 if (ret)
2101 goto end;
2102 ret = lttng_metadata_printf(session,
2103 "\"");
2104 if (ret)
2105 goto end;
2106 len = strlen(entry->string);
2107 /* Escape the character '"' */
2108 for (j = 0; j < len; j++) {
2109 char c = entry->string[j];
2110
2111 switch (c) {
2112 case '"':
2113 ret = lttng_metadata_printf(session,
2114 "\\\"");
2115 break;
2116 case '\\':
2117 ret = lttng_metadata_printf(session,
2118 "\\\\");
2119 break;
2120 default:
2121 ret = lttng_metadata_printf(session,
2122 "%c", c);
2123 break;
2124 }
2125 if (ret)
2126 goto end;
2127 }
2128 ret = lttng_metadata_printf(session, "\"");
2129 if (ret)
2130 goto end;
2131
2132 if (entry->options.is_auto) {
2133 ret = lttng_metadata_printf(session, ",\n");
2134 if (ret)
2135 goto end;
2136 } else {
2137 ret = lttng_metadata_printf(session,
2138 " = ");
2139 if (ret)
2140 goto end;
2141 if (entry->start.signedness)
2142 ret = lttng_metadata_printf(session,
2143 "%lld", (long long) entry->start.value);
2144 else
2145 ret = lttng_metadata_printf(session,
2146 "%llu", entry->start.value);
2147 if (ret)
2148 goto end;
2149 if (entry->start.signedness == entry->end.signedness &&
2150 entry->start.value
2151 == entry->end.value) {
2152 ret = lttng_metadata_printf(session,
2153 ",\n");
2154 } else {
2155 if (entry->end.signedness) {
2156 ret = lttng_metadata_printf(session,
2157 " ... %lld,\n",
2158 (long long) entry->end.value);
2159 } else {
2160 ret = lttng_metadata_printf(session,
2161 " ... %llu,\n",
2162 entry->end.value);
2163 }
2164 }
2165 if (ret)
2166 goto end;
2167 }
2168 }
2169 ret = print_tabs(session, nesting);
2170 if (ret)
2171 goto end;
2172 ret = lttng_metadata_printf(session, "} _%s;\n",
2173 field->name);
2174 end:
2175 return ret;
2176 }
2177
2178 /*
2179 * Must be called with sessions_mutex held.
2180 */
2181 static
2182 int _lttng_field_statedump(struct lttng_session *session,
2183 const struct lttng_event_field *field,
2184 size_t nesting)
2185 {
2186 int ret = 0;
2187
2188 switch (field->type.atype) {
2189 case atype_integer:
2190 ret = print_tabs(session, nesting);
2191 if (ret)
2192 return ret;
2193 ret = lttng_metadata_printf(session,
2194 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
2195 field->type.u.basic.integer.size,
2196 field->type.u.basic.integer.alignment,
2197 field->type.u.basic.integer.signedness,
2198 (field->type.u.basic.integer.encoding == lttng_encode_none)
2199 ? "none"
2200 : (field->type.u.basic.integer.encoding == lttng_encode_UTF8)
2201 ? "UTF8"
2202 : "ASCII",
2203 field->type.u.basic.integer.base,
2204 #if __BYTE_ORDER == __BIG_ENDIAN
2205 field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2206 #else
2207 field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2208 #endif
2209 field->name);
2210 break;
2211 case atype_enum:
2212 ret = _lttng_enum_statedump(session, field, nesting);
2213 break;
2214 case atype_array:
2215 case atype_array_bitfield:
2216 {
2217 const struct lttng_basic_type *elem_type;
2218
2219 elem_type = &field->type.u.array.elem_type;
2220 if (field->type.u.array.elem_alignment) {
2221 ret = print_tabs(session, nesting);
2222 if (ret)
2223 return ret;
2224 ret = lttng_metadata_printf(session,
2225 "struct { } align(%u) _%s_padding;\n",
2226 field->type.u.array.elem_alignment * CHAR_BIT,
2227 field->name);
2228 if (ret)
2229 return ret;
2230 }
2231 ret = print_tabs(session, nesting);
2232 if (ret)
2233 return ret;
2234 ret = lttng_metadata_printf(session,
2235 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
2236 elem_type->u.basic.integer.size,
2237 elem_type->u.basic.integer.alignment,
2238 elem_type->u.basic.integer.signedness,
2239 (elem_type->u.basic.integer.encoding == lttng_encode_none)
2240 ? "none"
2241 : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
2242 ? "UTF8"
2243 : "ASCII",
2244 elem_type->u.basic.integer.base,
2245 #if __BYTE_ORDER == __BIG_ENDIAN
2246 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2247 #else
2248 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2249 #endif
2250 field->name, field->type.u.array.length);
2251 break;
2252 }
2253 case atype_sequence:
2254 case atype_sequence_bitfield:
2255 {
2256 const struct lttng_basic_type *elem_type;
2257 const struct lttng_basic_type *length_type;
2258
2259 elem_type = &field->type.u.sequence.elem_type;
2260 length_type = &field->type.u.sequence.length_type;
2261 ret = print_tabs(session, nesting);
2262 if (ret)
2263 return ret;
2264 ret = lttng_metadata_printf(session,
2265 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
2266 length_type->u.basic.integer.size,
2267 (unsigned int) length_type->u.basic.integer.alignment,
2268 length_type->u.basic.integer.signedness,
2269 (length_type->u.basic.integer.encoding == lttng_encode_none)
2270 ? "none"
2271 : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8)
2272 ? "UTF8"
2273 : "ASCII"),
2274 length_type->u.basic.integer.base,
2275 #if __BYTE_ORDER == __BIG_ENDIAN
2276 length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2277 #else
2278 length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2279 #endif
2280 field->name);
2281 if (ret)
2282 return ret;
2283
2284 if (field->type.u.sequence.elem_alignment) {
2285 ret = print_tabs(session, nesting);
2286 if (ret)
2287 return ret;
2288 ret = lttng_metadata_printf(session,
2289 "struct { } align(%u) _%s_padding;\n",
2290 field->type.u.sequence.elem_alignment * CHAR_BIT,
2291 field->name);
2292 if (ret)
2293 return ret;
2294 }
2295 ret = print_tabs(session, nesting);
2296 if (ret)
2297 return ret;
2298 ret = lttng_metadata_printf(session,
2299 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
2300 elem_type->u.basic.integer.size,
2301 (unsigned int) elem_type->u.basic.integer.alignment,
2302 elem_type->u.basic.integer.signedness,
2303 (elem_type->u.basic.integer.encoding == lttng_encode_none)
2304 ? "none"
2305 : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
2306 ? "UTF8"
2307 : "ASCII"),
2308 elem_type->u.basic.integer.base,
2309 #if __BYTE_ORDER == __BIG_ENDIAN
2310 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2311 #else
2312 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2313 #endif
2314 field->name,
2315 field->name);
2316 break;
2317 }
2318
2319 case atype_string:
2320 /* Default encoding is UTF8 */
2321 ret = print_tabs(session, nesting);
2322 if (ret)
2323 return ret;
2324 ret = lttng_metadata_printf(session,
2325 "string%s _%s;\n",
2326 field->type.u.basic.string.encoding == lttng_encode_ASCII ?
2327 " { encoding = ASCII; }" : "",
2328 field->name);
2329 break;
2330 case atype_struct:
2331 ret = _lttng_struct_statedump(session, field, nesting);
2332 break;
2333 case atype_array_compound:
2334 ret = _lttng_array_compound_statedump(session, field, nesting);
2335 break;
2336 case atype_sequence_compound:
2337 ret = _lttng_sequence_compound_statedump(session, field, nesting);
2338 break;
2339 case atype_variant:
2340 ret = _lttng_variant_statedump(session, field, nesting);
2341 break;
2342
2343 default:
2344 WARN_ON_ONCE(1);
2345 return -EINVAL;
2346 }
2347 return ret;
2348 }
2349
2350 static
2351 int _lttng_context_metadata_statedump(struct lttng_session *session,
2352 struct lttng_ctx *ctx)
2353 {
2354 int ret = 0;
2355 int i;
2356
2357 if (!ctx)
2358 return 0;
2359 for (i = 0; i < ctx->nr_fields; i++) {
2360 const struct lttng_ctx_field *field = &ctx->fields[i];
2361
2362 ret = _lttng_field_statedump(session, &field->event_field, 2);
2363 if (ret)
2364 return ret;
2365 }
2366 return ret;
2367 }
2368
2369 static
2370 int _lttng_fields_metadata_statedump(struct lttng_session *session,
2371 struct lttng_event *event)
2372 {
2373 const struct lttng_event_desc *desc = event->desc;
2374 int ret = 0;
2375 int i;
2376
2377 for (i = 0; i < desc->nr_fields; i++) {
2378 const struct lttng_event_field *field = &desc->fields[i];
2379
2380 ret = _lttng_field_statedump(session, field, 2);
2381 if (ret)
2382 return ret;
2383 }
2384 return ret;
2385 }
2386
2387 /*
2388 * Must be called with sessions_mutex held.
2389 * The entire event metadata is printed as a single atomic metadata
2390 * transaction.
2391 */
2392 static
2393 int _lttng_event_metadata_statedump(struct lttng_session *session,
2394 struct lttng_channel *chan,
2395 struct lttng_event *event)
2396 {
2397 int ret = 0;
2398
2399 if (event->metadata_dumped || !LTTNG_READ_ONCE(session->active))
2400 return 0;
2401 if (chan->channel_type == METADATA_CHANNEL)
2402 return 0;
2403
2404 lttng_metadata_begin(session);
2405
2406 ret = lttng_metadata_printf(session,
2407 "event {\n"
2408 " name = \"%s\";\n"
2409 " id = %u;\n"
2410 " stream_id = %u;\n",
2411 event->desc->name,
2412 event->id,
2413 event->chan->id);
2414 if (ret)
2415 goto end;
2416
2417 if (event->ctx) {
2418 ret = lttng_metadata_printf(session,
2419 " context := struct {\n");
2420 if (ret)
2421 goto end;
2422 }
2423 ret = _lttng_context_metadata_statedump(session, event->ctx);
2424 if (ret)
2425 goto end;
2426 if (event->ctx) {
2427 ret = lttng_metadata_printf(session,
2428 " };\n");
2429 if (ret)
2430 goto end;
2431 }
2432
2433 ret = lttng_metadata_printf(session,
2434 " fields := struct {\n"
2435 );
2436 if (ret)
2437 goto end;
2438
2439 ret = _lttng_fields_metadata_statedump(session, event);
2440 if (ret)
2441 goto end;
2442
2443 /*
2444 * LTTng space reservation can only reserve multiples of the
2445 * byte size.
2446 */
2447 ret = lttng_metadata_printf(session,
2448 " };\n"
2449 "};\n\n");
2450 if (ret)
2451 goto end;
2452
2453 event->metadata_dumped = 1;
2454 end:
2455 lttng_metadata_end(session);
2456 return ret;
2457
2458 }
2459
2460 /*
2461 * Must be called with sessions_mutex held.
2462 * The entire channel metadata is printed as a single atomic metadata
2463 * transaction.
2464 */
2465 static
2466 int _lttng_channel_metadata_statedump(struct lttng_session *session,
2467 struct lttng_channel *chan)
2468 {
2469 int ret = 0;
2470
2471 if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
2472 return 0;
2473
2474 if (chan->channel_type == METADATA_CHANNEL)
2475 return 0;
2476
2477 lttng_metadata_begin(session);
2478
2479 WARN_ON_ONCE(!chan->header_type);
2480 ret = lttng_metadata_printf(session,
2481 "stream {\n"
2482 " id = %u;\n"
2483 " event.header := %s;\n"
2484 " packet.context := struct packet_context;\n",
2485 chan->id,
2486 chan->header_type == 1 ? "struct event_header_compact" :
2487 "struct event_header_large");
2488 if (ret)
2489 goto end;
2490
2491 if (chan->ctx) {
2492 ret = lttng_metadata_printf(session,
2493 " event.context := struct {\n");
2494 if (ret)
2495 goto end;
2496 }
2497 ret = _lttng_context_metadata_statedump(session, chan->ctx);
2498 if (ret)
2499 goto end;
2500 if (chan->ctx) {
2501 ret = lttng_metadata_printf(session,
2502 " };\n");
2503 if (ret)
2504 goto end;
2505 }
2506
2507 ret = lttng_metadata_printf(session,
2508 "};\n\n");
2509
2510 chan->metadata_dumped = 1;
2511 end:
2512 lttng_metadata_end(session);
2513 return ret;
2514 }
2515
2516 /*
2517 * Must be called with sessions_mutex held.
2518 */
2519 static
2520 int _lttng_stream_packet_context_declare(struct lttng_session *session)
2521 {
2522 return lttng_metadata_printf(session,
2523 "struct packet_context {\n"
2524 " uint64_clock_monotonic_t timestamp_begin;\n"
2525 " uint64_clock_monotonic_t timestamp_end;\n"
2526 " uint64_t content_size;\n"
2527 " uint64_t packet_size;\n"
2528 " uint64_t packet_seq_num;\n"
2529 " unsigned long events_discarded;\n"
2530 " uint32_t cpu_id;\n"
2531 "};\n\n"
2532 );
2533 }
2534
2535 /*
2536 * Compact header:
2537 * id: range: 0 - 30.
2538 * id 31 is reserved to indicate an extended header.
2539 *
2540 * Large header:
2541 * id: range: 0 - 65534.
2542 * id 65535 is reserved to indicate an extended header.
2543 *
2544 * Must be called with sessions_mutex held.
2545 */
2546 static
2547 int _lttng_event_header_declare(struct lttng_session *session)
2548 {
2549 return lttng_metadata_printf(session,
2550 "struct event_header_compact {\n"
2551 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
2552 " variant <id> {\n"
2553 " struct {\n"
2554 " uint27_clock_monotonic_t timestamp;\n"
2555 " } compact;\n"
2556 " struct {\n"
2557 " uint32_t id;\n"
2558 " uint64_clock_monotonic_t timestamp;\n"
2559 " } extended;\n"
2560 " } v;\n"
2561 "} align(%u);\n"
2562 "\n"
2563 "struct event_header_large {\n"
2564 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
2565 " variant <id> {\n"
2566 " struct {\n"
2567 " uint32_clock_monotonic_t timestamp;\n"
2568 " } compact;\n"
2569 " struct {\n"
2570 " uint32_t id;\n"
2571 " uint64_clock_monotonic_t timestamp;\n"
2572 " } extended;\n"
2573 " } v;\n"
2574 "} align(%u);\n\n",
2575 lttng_alignof(uint32_t) * CHAR_BIT,
2576 lttng_alignof(uint16_t) * CHAR_BIT
2577 );
2578 }
2579
2580 /*
2581 * Approximation of NTP time of day to clock monotonic correlation,
2582 * taken at start of trace.
2583 * Yes, this is only an approximation. Yes, we can (and will) do better
2584 * in future versions.
2585 * This function may return a negative offset. It may happen if the
2586 * system sets the REALTIME clock to 0 after boot.
2587 *
2588 * Use 64bit timespec on kernels that have it, this makes 32bit arch
2589 * y2038 compliant.
2590 */
2591 static
2592 int64_t measure_clock_offset(void)
2593 {
2594 uint64_t monotonic_avg, monotonic[2], realtime;
2595 uint64_t tcf = trace_clock_freq();
2596 int64_t offset;
2597 unsigned long flags;
2598 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
2599 struct timespec64 rts = { 0, 0 };
2600 #else
2601 struct timespec rts = { 0, 0 };
2602 #endif
2603
2604 /* Disable interrupts to increase correlation precision. */
2605 local_irq_save(flags);
2606 monotonic[0] = trace_clock_read64();
2607 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
2608 ktime_get_real_ts64(&rts);
2609 #else
2610 getnstimeofday(&rts);
2611 #endif
2612 monotonic[1] = trace_clock_read64();
2613 local_irq_restore(flags);
2614
2615 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
2616 realtime = (uint64_t) rts.tv_sec * tcf;
2617 if (tcf == NSEC_PER_SEC) {
2618 realtime += rts.tv_nsec;
2619 } else {
2620 uint64_t n = rts.tv_nsec * tcf;
2621
2622 do_div(n, NSEC_PER_SEC);
2623 realtime += n;
2624 }
2625 offset = (int64_t) realtime - monotonic_avg;
2626 return offset;
2627 }
2628
2629 static
2630 int print_escaped_ctf_string(struct lttng_session *session, const char *string)
2631 {
2632 int ret = 0;
2633 size_t i;
2634 char cur;
2635
2636 i = 0;
2637 cur = string[i];
2638 while (cur != '\0') {
2639 switch (cur) {
2640 case '\n':
2641 ret = lttng_metadata_printf(session, "%s", "\\n");
2642 break;
2643 case '\\':
2644 case '"':
2645 ret = lttng_metadata_printf(session, "%c", '\\');
2646 if (ret)
2647 goto error;
2648 /* We still print the current char */
2649 /* Fallthrough */
2650 default:
2651 ret = lttng_metadata_printf(session, "%c", cur);
2652 break;
2653 }
2654
2655 if (ret)
2656 goto error;
2657
2658 cur = string[++i];
2659 }
2660 error:
2661 return ret;
2662 }
2663
2664 static
2665 int print_metadata_escaped_field(struct lttng_session *session, const char *field,
2666 const char *field_value)
2667 {
2668 int ret;
2669
2670 ret = lttng_metadata_printf(session, " %s = \"", field);
2671 if (ret)
2672 goto error;
2673
2674 ret = print_escaped_ctf_string(session, field_value);
2675 if (ret)
2676 goto error;
2677
2678 ret = lttng_metadata_printf(session, "\";\n");
2679
2680 error:
2681 return ret;
2682 }
2683
2684 /*
2685 * Output metadata into this session's metadata buffers.
2686 * Must be called with sessions_mutex held.
2687 */
2688 static
2689 int _lttng_session_metadata_statedump(struct lttng_session *session)
2690 {
2691 unsigned char *uuid_c = session->uuid.b;
2692 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
2693 const char *product_uuid;
2694 struct lttng_channel *chan;
2695 struct lttng_event *event;
2696 int ret = 0;
2697
2698 if (!LTTNG_READ_ONCE(session->active))
2699 return 0;
2700
2701 lttng_metadata_begin(session);
2702
2703 if (session->metadata_dumped)
2704 goto skip_session;
2705
2706 snprintf(uuid_s, sizeof(uuid_s),
2707 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
2708 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
2709 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
2710 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
2711 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
2712
2713 ret = lttng_metadata_printf(session,
2714 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
2715 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
2716 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
2717 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
2718 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
2719 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
2720 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
2721 "\n"
2722 "trace {\n"
2723 " major = %u;\n"
2724 " minor = %u;\n"
2725 " uuid = \"%s\";\n"
2726 " byte_order = %s;\n"
2727 " packet.header := struct {\n"
2728 " uint32_t magic;\n"
2729 " uint8_t uuid[16];\n"
2730 " uint32_t stream_id;\n"
2731 " uint64_t stream_instance_id;\n"
2732 " };\n"
2733 "};\n\n",
2734 lttng_alignof(uint8_t) * CHAR_BIT,
2735 lttng_alignof(uint16_t) * CHAR_BIT,
2736 lttng_alignof(uint32_t) * CHAR_BIT,
2737 lttng_alignof(uint64_t) * CHAR_BIT,
2738 sizeof(unsigned long) * CHAR_BIT,
2739 lttng_alignof(unsigned long) * CHAR_BIT,
2740 CTF_SPEC_MAJOR,
2741 CTF_SPEC_MINOR,
2742 uuid_s,
2743 #if __BYTE_ORDER == __BIG_ENDIAN
2744 "be"
2745 #else
2746 "le"
2747 #endif
2748 );
2749 if (ret)
2750 goto end;
2751
2752 ret = lttng_metadata_printf(session,
2753 "env {\n"
2754 " hostname = \"%s\";\n"
2755 " domain = \"kernel\";\n"
2756 " sysname = \"%s\";\n"
2757 " kernel_release = \"%s\";\n"
2758 " kernel_version = \"%s\";\n"
2759 " tracer_name = \"lttng-modules\";\n"
2760 " tracer_major = %d;\n"
2761 " tracer_minor = %d;\n"
2762 " tracer_patchlevel = %d;\n"
2763 " trace_buffering_scheme = \"global\";\n",
2764 current->nsproxy->uts_ns->name.nodename,
2765 utsname()->sysname,
2766 utsname()->release,
2767 utsname()->version,
2768 LTTNG_MODULES_MAJOR_VERSION,
2769 LTTNG_MODULES_MINOR_VERSION,
2770 LTTNG_MODULES_PATCHLEVEL_VERSION
2771 );
2772 if (ret)
2773 goto end;
2774
2775 ret = print_metadata_escaped_field(session, "trace_name", session->name);
2776 if (ret)
2777 goto end;
2778 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
2779 session->creation_time);
2780 if (ret)
2781 goto end;
2782
2783 /* Add the product UUID to the 'env' section */
2784 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
2785 if (product_uuid) {
2786 ret = lttng_metadata_printf(session,
2787 " product_uuid = \"%s\";\n",
2788 product_uuid
2789 );
2790 if (ret)
2791 goto end;
2792 }
2793
2794 /* Close the 'env' section */
2795 ret = lttng_metadata_printf(session, "};\n\n");
2796 if (ret)
2797 goto end;
2798
2799 ret = lttng_metadata_printf(session,
2800 "clock {\n"
2801 " name = \"%s\";\n",
2802 trace_clock_name()
2803 );
2804 if (ret)
2805 goto end;
2806
2807 if (!trace_clock_uuid(clock_uuid_s)) {
2808 ret = lttng_metadata_printf(session,
2809 " uuid = \"%s\";\n",
2810 clock_uuid_s
2811 );
2812 if (ret)
2813 goto end;
2814 }
2815
2816 ret = lttng_metadata_printf(session,
2817 " description = \"%s\";\n"
2818 " freq = %llu; /* Frequency, in Hz */\n"
2819 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
2820 " offset = %lld;\n"
2821 "};\n\n",
2822 trace_clock_description(),
2823 (unsigned long long) trace_clock_freq(),
2824 (long long) measure_clock_offset()
2825 );
2826 if (ret)
2827 goto end;
2828
2829 ret = lttng_metadata_printf(session,
2830 "typealias integer {\n"
2831 " size = 27; align = 1; signed = false;\n"
2832 " map = clock.%s.value;\n"
2833 "} := uint27_clock_monotonic_t;\n"
2834 "\n"
2835 "typealias integer {\n"
2836 " size = 32; align = %u; signed = false;\n"
2837 " map = clock.%s.value;\n"
2838 "} := uint32_clock_monotonic_t;\n"
2839 "\n"
2840 "typealias integer {\n"
2841 " size = 64; align = %u; signed = false;\n"
2842 " map = clock.%s.value;\n"
2843 "} := uint64_clock_monotonic_t;\n\n",
2844 trace_clock_name(),
2845 lttng_alignof(uint32_t) * CHAR_BIT,
2846 trace_clock_name(),
2847 lttng_alignof(uint64_t) * CHAR_BIT,
2848 trace_clock_name()
2849 );
2850 if (ret)
2851 goto end;
2852
2853 ret = _lttng_stream_packet_context_declare(session);
2854 if (ret)
2855 goto end;
2856
2857 ret = _lttng_event_header_declare(session);
2858 if (ret)
2859 goto end;
2860
2861 skip_session:
2862 list_for_each_entry(chan, &session->chan, list) {
2863 ret = _lttng_channel_metadata_statedump(session, chan);
2864 if (ret)
2865 goto end;
2866 }
2867
2868 list_for_each_entry(event, &session->events, list) {
2869 ret = _lttng_event_metadata_statedump(session, event->chan, event);
2870 if (ret)
2871 goto end;
2872 }
2873 session->metadata_dumped = 1;
2874 end:
2875 lttng_metadata_end(session);
2876 return ret;
2877 }
2878
2879 /**
2880 * lttng_transport_register - LTT transport registration
2881 * @transport: transport structure
2882 *
2883 * Registers a transport which can be used as output to extract the data out of
2884 * LTTng. The module calling this registration function must ensure that no
2885 * trap-inducing code will be executed by the transport functions. E.g.
2886 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
2887 * is made visible to the transport function. This registration acts as a
2888 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
2889 * after its registration must it synchronize the TLBs.
2890 */
2891 void lttng_transport_register(struct lttng_transport *transport)
2892 {
2893 /*
2894 * Make sure no page fault can be triggered by the module about to be
2895 * registered. We deal with this here so we don't have to call
2896 * vmalloc_sync_mappings() in each module's init.
2897 */
2898 wrapper_vmalloc_sync_mappings();
2899
2900 mutex_lock(&sessions_mutex);
2901 list_add_tail(&transport->node, &lttng_transport_list);
2902 mutex_unlock(&sessions_mutex);
2903 }
2904 EXPORT_SYMBOL_GPL(lttng_transport_register);
2905
2906 /**
2907 * lttng_transport_unregister - LTT transport unregistration
2908 * @transport: transport structure
2909 */
2910 void lttng_transport_unregister(struct lttng_transport *transport)
2911 {
2912 mutex_lock(&sessions_mutex);
2913 list_del(&transport->node);
2914 mutex_unlock(&sessions_mutex);
2915 }
2916 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
2917
2918 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
2919
2920 enum cpuhp_state lttng_hp_prepare;
2921 enum cpuhp_state lttng_hp_online;
2922
2923 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
2924 {
2925 struct lttng_cpuhp_node *lttng_node;
2926
2927 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2928 switch (lttng_node->component) {
2929 case LTTNG_RING_BUFFER_FRONTEND:
2930 return 0;
2931 case LTTNG_RING_BUFFER_BACKEND:
2932 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
2933 case LTTNG_RING_BUFFER_ITER:
2934 return 0;
2935 case LTTNG_CONTEXT_PERF_COUNTERS:
2936 return 0;
2937 default:
2938 return -EINVAL;
2939 }
2940 }
2941
2942 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
2943 {
2944 struct lttng_cpuhp_node *lttng_node;
2945
2946 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2947 switch (lttng_node->component) {
2948 case LTTNG_RING_BUFFER_FRONTEND:
2949 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
2950 case LTTNG_RING_BUFFER_BACKEND:
2951 return 0;
2952 case LTTNG_RING_BUFFER_ITER:
2953 return 0;
2954 case LTTNG_CONTEXT_PERF_COUNTERS:
2955 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
2956 default:
2957 return -EINVAL;
2958 }
2959 }
2960
2961 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
2962 {
2963 struct lttng_cpuhp_node *lttng_node;
2964
2965 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2966 switch (lttng_node->component) {
2967 case LTTNG_RING_BUFFER_FRONTEND:
2968 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
2969 case LTTNG_RING_BUFFER_BACKEND:
2970 return 0;
2971 case LTTNG_RING_BUFFER_ITER:
2972 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
2973 case LTTNG_CONTEXT_PERF_COUNTERS:
2974 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
2975 default:
2976 return -EINVAL;
2977 }
2978 }
2979
2980 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
2981 {
2982 struct lttng_cpuhp_node *lttng_node;
2983
2984 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2985 switch (lttng_node->component) {
2986 case LTTNG_RING_BUFFER_FRONTEND:
2987 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
2988 case LTTNG_RING_BUFFER_BACKEND:
2989 return 0;
2990 case LTTNG_RING_BUFFER_ITER:
2991 return 0;
2992 case LTTNG_CONTEXT_PERF_COUNTERS:
2993 return 0;
2994 default:
2995 return -EINVAL;
2996 }
2997 }
2998
2999 static int __init lttng_init_cpu_hotplug(void)
3000 {
3001 int ret;
3002
3003 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
3004 lttng_hotplug_prepare,
3005 lttng_hotplug_dead);
3006 if (ret < 0) {
3007 return ret;
3008 }
3009 lttng_hp_prepare = ret;
3010 lttng_rb_set_hp_prepare(ret);
3011
3012 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
3013 lttng_hotplug_online,
3014 lttng_hotplug_offline);
3015 if (ret < 0) {
3016 cpuhp_remove_multi_state(lttng_hp_prepare);
3017 lttng_hp_prepare = 0;
3018 return ret;
3019 }
3020 lttng_hp_online = ret;
3021 lttng_rb_set_hp_online(ret);
3022
3023 return 0;
3024 }
3025
3026 static void __exit lttng_exit_cpu_hotplug(void)
3027 {
3028 lttng_rb_set_hp_online(0);
3029 cpuhp_remove_multi_state(lttng_hp_online);
3030 lttng_rb_set_hp_prepare(0);
3031 cpuhp_remove_multi_state(lttng_hp_prepare);
3032 }
3033
3034 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
3035 static int lttng_init_cpu_hotplug(void)
3036 {
3037 return 0;
3038 }
3039 static void lttng_exit_cpu_hotplug(void)
3040 {
3041 }
3042 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
3043
3044
3045 static int __init lttng_events_init(void)
3046 {
3047 int ret;
3048
3049 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
3050 if (ret)
3051 return ret;
3052 ret = wrapper_get_pfnblock_flags_mask_init();
3053 if (ret)
3054 return ret;
3055 ret = wrapper_get_pageblock_flags_mask_init();
3056 if (ret)
3057 return ret;
3058 ret = lttng_probes_init();
3059 if (ret)
3060 return ret;
3061 ret = lttng_context_init();
3062 if (ret)
3063 return ret;
3064 ret = lttng_tracepoint_init();
3065 if (ret)
3066 goto error_tp;
3067 event_cache = KMEM_CACHE(lttng_event, 0);
3068 if (!event_cache) {
3069 ret = -ENOMEM;
3070 goto error_kmem;
3071 }
3072 ret = lttng_abi_init();
3073 if (ret)
3074 goto error_abi;
3075 ret = lttng_logger_init();
3076 if (ret)
3077 goto error_logger;
3078 ret = lttng_init_cpu_hotplug();
3079 if (ret)
3080 goto error_hotplug;
3081 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
3082 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3083 __stringify(LTTNG_MODULES_MINOR_VERSION),
3084 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3085 LTTNG_MODULES_EXTRAVERSION,
3086 LTTNG_VERSION_NAME,
3087 #ifdef LTTNG_EXTRA_VERSION_GIT
3088 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3089 #else
3090 "",
3091 #endif
3092 #ifdef LTTNG_EXTRA_VERSION_NAME
3093 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3094 #else
3095 "");
3096 #endif
3097 return 0;
3098
3099 error_hotplug:
3100 lttng_logger_exit();
3101 error_logger:
3102 lttng_abi_exit();
3103 error_abi:
3104 kmem_cache_destroy(event_cache);
3105 error_kmem:
3106 lttng_tracepoint_exit();
3107 error_tp:
3108 lttng_context_exit();
3109 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
3110 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3111 __stringify(LTTNG_MODULES_MINOR_VERSION),
3112 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3113 LTTNG_MODULES_EXTRAVERSION,
3114 LTTNG_VERSION_NAME,
3115 #ifdef LTTNG_EXTRA_VERSION_GIT
3116 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3117 #else
3118 "",
3119 #endif
3120 #ifdef LTTNG_EXTRA_VERSION_NAME
3121 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3122 #else
3123 "");
3124 #endif
3125 return ret;
3126 }
3127
3128 module_init(lttng_events_init);
3129
3130 static void __exit lttng_events_exit(void)
3131 {
3132 struct lttng_session *session, *tmpsession;
3133
3134 lttng_exit_cpu_hotplug();
3135 lttng_logger_exit();
3136 lttng_abi_exit();
3137 list_for_each_entry_safe(session, tmpsession, &sessions, list)
3138 lttng_session_destroy(session);
3139 kmem_cache_destroy(event_cache);
3140 lttng_tracepoint_exit();
3141 lttng_context_exit();
3142 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
3143 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3144 __stringify(LTTNG_MODULES_MINOR_VERSION),
3145 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3146 LTTNG_MODULES_EXTRAVERSION,
3147 LTTNG_VERSION_NAME,
3148 #ifdef LTTNG_EXTRA_VERSION_GIT
3149 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3150 #else
3151 "",
3152 #endif
3153 #ifdef LTTNG_EXTRA_VERSION_NAME
3154 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3155 #else
3156 "");
3157 #endif
3158 }
3159
3160 module_exit(lttng_events_exit);
3161
3162 #include "extra_version/patches.i"
3163 #ifdef LTTNG_EXTRA_VERSION_GIT
3164 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
3165 #endif
3166 #ifdef LTTNG_EXTRA_VERSION_NAME
3167 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
3168 #endif
3169 MODULE_LICENSE("GPL and additional rights");
3170 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
3171 MODULE_DESCRIPTION("LTTng tracer");
3172 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
3173 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
3174 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
3175 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
This page took 0.156593 seconds and 4 git commands to generate.