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fix: block: move block-related definitions out of fs.h (v5.16)
[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/compiler_attributes.h>
45 #include <wrapper/ringbuffer/backend.h>
46 #include <wrapper/ringbuffer/frontend.h>
47 #include <wrapper/time.h>
48
49 #define METADATA_CACHE_DEFAULT_SIZE 4096
50
51 static LIST_HEAD(sessions);
52 static LIST_HEAD(lttng_transport_list);
53 /*
54 * Protect the sessions and metadata caches.
55 */
56 static DEFINE_MUTEX(sessions_mutex);
57 static struct kmem_cache *event_cache;
58
59 static void lttng_session_lazy_sync_enablers(struct lttng_session *session);
60 static void lttng_session_sync_enablers(struct lttng_session *session);
61 static void lttng_enabler_destroy(struct lttng_enabler *enabler);
62
63 static void _lttng_event_destroy(struct lttng_event *event);
64 static void _lttng_channel_destroy(struct lttng_channel *chan);
65 static int _lttng_event_unregister(struct lttng_event *event);
66 static
67 int _lttng_event_metadata_statedump(struct lttng_session *session,
68 struct lttng_channel *chan,
69 struct lttng_event *event);
70 static
71 int _lttng_session_metadata_statedump(struct lttng_session *session);
72 static
73 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
74 static
75 int _lttng_field_statedump(struct lttng_session *session,
76 const struct lttng_event_field *field,
77 size_t nesting);
78
79 void synchronize_trace(void)
80 {
81 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0) || \
82 LTTNG_RHEL_KERNEL_RANGE(4,18,0,193,0,0, 4,19,0,0,0,0))
83 synchronize_rcu();
84 #else
85 synchronize_sched();
86 #endif
87
88 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
89 #ifdef CONFIG_PREEMPT_RT_FULL
90 synchronize_rcu();
91 #endif
92 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
93 #ifdef CONFIG_PREEMPT_RT
94 synchronize_rcu();
95 #endif
96 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
97 }
98
99 void lttng_lock_sessions(void)
100 {
101 mutex_lock(&sessions_mutex);
102 }
103
104 void lttng_unlock_sessions(void)
105 {
106 mutex_unlock(&sessions_mutex);
107 }
108
109 /*
110 * Called with sessions lock held.
111 */
112 int lttng_session_active(void)
113 {
114 struct lttng_session *iter;
115
116 list_for_each_entry(iter, &sessions, list) {
117 if (iter->active)
118 return 1;
119 }
120 return 0;
121 }
122
123 struct lttng_session *lttng_session_create(void)
124 {
125 struct lttng_session *session;
126 struct lttng_metadata_cache *metadata_cache;
127 int i;
128
129 mutex_lock(&sessions_mutex);
130 session = lttng_kvzalloc(sizeof(struct lttng_session), GFP_KERNEL);
131 if (!session)
132 goto err;
133 INIT_LIST_HEAD(&session->chan);
134 INIT_LIST_HEAD(&session->events);
135 lttng_guid_gen(&session->uuid);
136
137 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
138 GFP_KERNEL);
139 if (!metadata_cache)
140 goto err_free_session;
141 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
142 if (!metadata_cache->data)
143 goto err_free_cache;
144 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
145 kref_init(&metadata_cache->refcount);
146 mutex_init(&metadata_cache->lock);
147 session->metadata_cache = metadata_cache;
148 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
149 memcpy(&metadata_cache->uuid, &session->uuid,
150 sizeof(metadata_cache->uuid));
151 INIT_LIST_HEAD(&session->enablers_head);
152 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
153 INIT_HLIST_HEAD(&session->events_ht.table[i]);
154 list_add(&session->list, &sessions);
155 session->pid_tracker.session = session;
156 session->pid_tracker.tracker_type = TRACKER_PID;
157 session->vpid_tracker.session = session;
158 session->vpid_tracker.tracker_type = TRACKER_VPID;
159 session->uid_tracker.session = session;
160 session->uid_tracker.tracker_type = TRACKER_UID;
161 session->vuid_tracker.session = session;
162 session->vuid_tracker.tracker_type = TRACKER_VUID;
163 session->gid_tracker.session = session;
164 session->gid_tracker.tracker_type = TRACKER_GID;
165 session->vgid_tracker.session = session;
166 session->vgid_tracker.tracker_type = TRACKER_VGID;
167 mutex_unlock(&sessions_mutex);
168 return session;
169
170 err_free_cache:
171 kfree(metadata_cache);
172 err_free_session:
173 lttng_kvfree(session);
174 err:
175 mutex_unlock(&sessions_mutex);
176 return NULL;
177 }
178
179 void metadata_cache_destroy(struct kref *kref)
180 {
181 struct lttng_metadata_cache *cache =
182 container_of(kref, struct lttng_metadata_cache, refcount);
183 vfree(cache->data);
184 kfree(cache);
185 }
186
187 void lttng_session_destroy(struct lttng_session *session)
188 {
189 struct lttng_channel *chan, *tmpchan;
190 struct lttng_event *event, *tmpevent;
191 struct lttng_metadata_stream *metadata_stream;
192 struct lttng_enabler *enabler, *tmpenabler;
193 int ret;
194
195 mutex_lock(&sessions_mutex);
196 WRITE_ONCE(session->active, 0);
197 list_for_each_entry(chan, &session->chan, list) {
198 ret = lttng_syscalls_unregister(chan);
199 WARN_ON(ret);
200 }
201 list_for_each_entry(event, &session->events, list) {
202 ret = _lttng_event_unregister(event);
203 WARN_ON(ret);
204 }
205 synchronize_trace(); /* Wait for in-flight events to complete */
206 list_for_each_entry(chan, &session->chan, list) {
207 ret = lttng_syscalls_destroy(chan);
208 WARN_ON(ret);
209 }
210 list_for_each_entry_safe(enabler, tmpenabler,
211 &session->enablers_head, node)
212 lttng_enabler_destroy(enabler);
213 list_for_each_entry_safe(event, tmpevent, &session->events, list)
214 _lttng_event_destroy(event);
215 list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
216 BUG_ON(chan->channel_type == METADATA_CHANNEL);
217 _lttng_channel_destroy(chan);
218 }
219 mutex_lock(&session->metadata_cache->lock);
220 list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
221 _lttng_metadata_channel_hangup(metadata_stream);
222 mutex_unlock(&session->metadata_cache->lock);
223 lttng_id_tracker_destroy(&session->pid_tracker, false);
224 lttng_id_tracker_destroy(&session->vpid_tracker, false);
225 lttng_id_tracker_destroy(&session->uid_tracker, false);
226 lttng_id_tracker_destroy(&session->vuid_tracker, false);
227 lttng_id_tracker_destroy(&session->gid_tracker, false);
228 lttng_id_tracker_destroy(&session->vgid_tracker, false);
229 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
230 list_del(&session->list);
231 mutex_unlock(&sessions_mutex);
232 lttng_kvfree(session);
233 }
234
235 int lttng_session_statedump(struct lttng_session *session)
236 {
237 int ret;
238
239 mutex_lock(&sessions_mutex);
240 ret = lttng_statedump_start(session);
241 mutex_unlock(&sessions_mutex);
242 return ret;
243 }
244
245 int lttng_session_enable(struct lttng_session *session)
246 {
247 int ret = 0;
248 struct lttng_channel *chan;
249
250 mutex_lock(&sessions_mutex);
251 if (session->active) {
252 ret = -EBUSY;
253 goto end;
254 }
255
256 /* Set transient enabler state to "enabled" */
257 session->tstate = 1;
258
259 /* We need to sync enablers with session before activation. */
260 lttng_session_sync_enablers(session);
261
262 /*
263 * Snapshot the number of events per channel to know the type of header
264 * we need to use.
265 */
266 list_for_each_entry(chan, &session->chan, list) {
267 if (chan->header_type)
268 continue; /* don't change it if session stop/restart */
269 if (chan->free_event_id < 31)
270 chan->header_type = 1; /* compact */
271 else
272 chan->header_type = 2; /* large */
273 }
274
275 /* Clear each stream's quiescent state. */
276 list_for_each_entry(chan, &session->chan, list) {
277 if (chan->channel_type != METADATA_CHANNEL)
278 lib_ring_buffer_clear_quiescent_channel(chan->chan);
279 }
280
281 WRITE_ONCE(session->active, 1);
282 WRITE_ONCE(session->been_active, 1);
283 ret = _lttng_session_metadata_statedump(session);
284 if (ret) {
285 WRITE_ONCE(session->active, 0);
286 goto end;
287 }
288 ret = lttng_statedump_start(session);
289 if (ret)
290 WRITE_ONCE(session->active, 0);
291 end:
292 mutex_unlock(&sessions_mutex);
293 return ret;
294 }
295
296 int lttng_session_disable(struct lttng_session *session)
297 {
298 int ret = 0;
299 struct lttng_channel *chan;
300
301 mutex_lock(&sessions_mutex);
302 if (!session->active) {
303 ret = -EBUSY;
304 goto end;
305 }
306 WRITE_ONCE(session->active, 0);
307
308 /* Set transient enabler state to "disabled" */
309 session->tstate = 0;
310 lttng_session_sync_enablers(session);
311
312 /* Set each stream's quiescent state. */
313 list_for_each_entry(chan, &session->chan, list) {
314 if (chan->channel_type != METADATA_CHANNEL)
315 lib_ring_buffer_set_quiescent_channel(chan->chan);
316 }
317 end:
318 mutex_unlock(&sessions_mutex);
319 return ret;
320 }
321
322 int lttng_session_metadata_regenerate(struct lttng_session *session)
323 {
324 int ret = 0;
325 struct lttng_channel *chan;
326 struct lttng_event *event;
327 struct lttng_metadata_cache *cache = session->metadata_cache;
328 struct lttng_metadata_stream *stream;
329
330 mutex_lock(&sessions_mutex);
331 if (!session->active) {
332 ret = -EBUSY;
333 goto end;
334 }
335
336 mutex_lock(&cache->lock);
337 memset(cache->data, 0, cache->cache_alloc);
338 cache->metadata_written = 0;
339 cache->version++;
340 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list) {
341 stream->metadata_out = 0;
342 stream->metadata_in = 0;
343 }
344 mutex_unlock(&cache->lock);
345
346 session->metadata_dumped = 0;
347 list_for_each_entry(chan, &session->chan, list) {
348 chan->metadata_dumped = 0;
349 }
350
351 list_for_each_entry(event, &session->events, list) {
352 event->metadata_dumped = 0;
353 }
354
355 ret = _lttng_session_metadata_statedump(session);
356
357 end:
358 mutex_unlock(&sessions_mutex);
359 return ret;
360 }
361
362 int lttng_channel_enable(struct lttng_channel *channel)
363 {
364 int ret = 0;
365
366 mutex_lock(&sessions_mutex);
367 if (channel->channel_type == METADATA_CHANNEL) {
368 ret = -EPERM;
369 goto end;
370 }
371 if (channel->enabled) {
372 ret = -EEXIST;
373 goto end;
374 }
375 /* Set transient enabler state to "enabled" */
376 channel->tstate = 1;
377 lttng_session_sync_enablers(channel->session);
378 /* Set atomically the state to "enabled" */
379 WRITE_ONCE(channel->enabled, 1);
380 end:
381 mutex_unlock(&sessions_mutex);
382 return ret;
383 }
384
385 int lttng_channel_disable(struct lttng_channel *channel)
386 {
387 int ret = 0;
388
389 mutex_lock(&sessions_mutex);
390 if (channel->channel_type == METADATA_CHANNEL) {
391 ret = -EPERM;
392 goto end;
393 }
394 if (!channel->enabled) {
395 ret = -EEXIST;
396 goto end;
397 }
398 /* Set atomically the state to "disabled" */
399 WRITE_ONCE(channel->enabled, 0);
400 /* Set transient enabler state to "enabled" */
401 channel->tstate = 0;
402 lttng_session_sync_enablers(channel->session);
403 end:
404 mutex_unlock(&sessions_mutex);
405 return ret;
406 }
407
408 int lttng_event_enable(struct lttng_event *event)
409 {
410 int ret = 0;
411
412 mutex_lock(&sessions_mutex);
413 if (event->chan->channel_type == METADATA_CHANNEL) {
414 ret = -EPERM;
415 goto end;
416 }
417 if (event->enabled) {
418 ret = -EEXIST;
419 goto end;
420 }
421 switch (event->instrumentation) {
422 case LTTNG_KERNEL_TRACEPOINT:
423 case LTTNG_KERNEL_SYSCALL:
424 ret = -EINVAL;
425 break;
426 case LTTNG_KERNEL_KPROBE:
427 case LTTNG_KERNEL_UPROBE:
428 case LTTNG_KERNEL_NOOP:
429 WRITE_ONCE(event->enabled, 1);
430 break;
431 case LTTNG_KERNEL_KRETPROBE:
432 ret = lttng_kretprobes_event_enable_state(event, 1);
433 break;
434 case LTTNG_KERNEL_FUNCTION:
435 lttng_fallthrough;
436 default:
437 WARN_ON_ONCE(1);
438 ret = -EINVAL;
439 }
440 end:
441 mutex_unlock(&sessions_mutex);
442 return ret;
443 }
444
445 int lttng_event_disable(struct lttng_event *event)
446 {
447 int ret = 0;
448
449 mutex_lock(&sessions_mutex);
450 if (event->chan->channel_type == METADATA_CHANNEL) {
451 ret = -EPERM;
452 goto end;
453 }
454 if (!event->enabled) {
455 ret = -EEXIST;
456 goto end;
457 }
458 switch (event->instrumentation) {
459 case LTTNG_KERNEL_TRACEPOINT:
460 case LTTNG_KERNEL_SYSCALL:
461 ret = -EINVAL;
462 break;
463 case LTTNG_KERNEL_KPROBE:
464 case LTTNG_KERNEL_UPROBE:
465 case LTTNG_KERNEL_NOOP:
466 WRITE_ONCE(event->enabled, 0);
467 break;
468 case LTTNG_KERNEL_KRETPROBE:
469 ret = lttng_kretprobes_event_enable_state(event, 0);
470 break;
471 case LTTNG_KERNEL_FUNCTION:
472 lttng_fallthrough;
473 default:
474 WARN_ON_ONCE(1);
475 ret = -EINVAL;
476 }
477 end:
478 mutex_unlock(&sessions_mutex);
479 return ret;
480 }
481
482 static struct lttng_transport *lttng_transport_find(const char *name)
483 {
484 struct lttng_transport *transport;
485
486 list_for_each_entry(transport, &lttng_transport_list, node) {
487 if (!strcmp(transport->name, name))
488 return transport;
489 }
490 return NULL;
491 }
492
493 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
494 const char *transport_name,
495 void *buf_addr,
496 size_t subbuf_size, size_t num_subbuf,
497 unsigned int switch_timer_interval,
498 unsigned int read_timer_interval,
499 enum channel_type channel_type)
500 {
501 struct lttng_channel *chan;
502 struct lttng_transport *transport = NULL;
503
504 mutex_lock(&sessions_mutex);
505 if (session->been_active && channel_type != METADATA_CHANNEL)
506 goto active; /* Refuse to add channel to active session */
507 transport = lttng_transport_find(transport_name);
508 if (!transport) {
509 printk(KERN_WARNING "LTTng transport %s not found\n",
510 transport_name);
511 goto notransport;
512 }
513 if (!try_module_get(transport->owner)) {
514 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
515 goto notransport;
516 }
517 chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL);
518 if (!chan)
519 goto nomem;
520 chan->session = session;
521 chan->id = session->free_chan_id++;
522 chan->ops = &transport->ops;
523 /*
524 * Note: the channel creation op already writes into the packet
525 * headers. Therefore the "chan" information used as input
526 * should be already accessible.
527 */
528 chan->chan = transport->ops.channel_create(transport_name,
529 chan, buf_addr, subbuf_size, num_subbuf,
530 switch_timer_interval, read_timer_interval);
531 if (!chan->chan)
532 goto create_error;
533 chan->tstate = 1;
534 chan->enabled = 1;
535 chan->transport = transport;
536 chan->channel_type = channel_type;
537 list_add(&chan->list, &session->chan);
538 mutex_unlock(&sessions_mutex);
539 return chan;
540
541 create_error:
542 kfree(chan);
543 nomem:
544 if (transport)
545 module_put(transport->owner);
546 notransport:
547 active:
548 mutex_unlock(&sessions_mutex);
549 return NULL;
550 }
551
552 /*
553 * Only used internally at session destruction for per-cpu channels, and
554 * when metadata channel is released.
555 * Needs to be called with sessions mutex held.
556 */
557 static
558 void _lttng_channel_destroy(struct lttng_channel *chan)
559 {
560 chan->ops->channel_destroy(chan->chan);
561 module_put(chan->transport->owner);
562 list_del(&chan->list);
563 lttng_destroy_context(chan->ctx);
564 kfree(chan);
565 }
566
567 void lttng_metadata_channel_destroy(struct lttng_channel *chan)
568 {
569 BUG_ON(chan->channel_type != METADATA_CHANNEL);
570
571 /* Protect the metadata cache with the sessions_mutex. */
572 mutex_lock(&sessions_mutex);
573 _lttng_channel_destroy(chan);
574 mutex_unlock(&sessions_mutex);
575 }
576 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
577
578 static
579 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
580 {
581 stream->finalized = 1;
582 wake_up_interruptible(&stream->read_wait);
583 }
584
585 /*
586 * Supports event creation while tracing session is active.
587 * Needs to be called with sessions mutex held.
588 */
589 struct lttng_event *_lttng_event_create(struct lttng_channel *chan,
590 struct lttng_kernel_event *event_param,
591 void *filter,
592 const struct lttng_event_desc *event_desc,
593 enum lttng_kernel_instrumentation itype)
594 {
595 struct lttng_session *session = chan->session;
596 struct lttng_event *event;
597 const char *event_name;
598 struct hlist_head *head;
599 size_t name_len;
600 uint32_t hash;
601 int ret;
602
603 if (chan->free_event_id == -1U) {
604 ret = -EMFILE;
605 goto full;
606 }
607
608 switch (itype) {
609 case LTTNG_KERNEL_TRACEPOINT:
610 event_name = event_desc->name;
611 break;
612 case LTTNG_KERNEL_KPROBE:
613 case LTTNG_KERNEL_UPROBE:
614 case LTTNG_KERNEL_KRETPROBE:
615 case LTTNG_KERNEL_NOOP:
616 case LTTNG_KERNEL_SYSCALL:
617 event_name = event_param->name;
618 break;
619 case LTTNG_KERNEL_FUNCTION:
620 lttng_fallthrough;
621 default:
622 WARN_ON_ONCE(1);
623 ret = -EINVAL;
624 goto type_error;
625 }
626 name_len = strlen(event_name);
627 hash = jhash(event_name, name_len, 0);
628 head = &session->events_ht.table[hash & (LTTNG_EVENT_HT_SIZE - 1)];
629 lttng_hlist_for_each_entry(event, head, hlist) {
630 WARN_ON_ONCE(!event->desc);
631 if (!strncmp(event->desc->name, event_name,
632 LTTNG_KERNEL_SYM_NAME_LEN - 1)
633 && chan == event->chan) {
634 ret = -EEXIST;
635 goto exist;
636 }
637 }
638
639 event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
640 if (!event) {
641 ret = -ENOMEM;
642 goto cache_error;
643 }
644 event->chan = chan;
645 event->filter = filter;
646 event->id = chan->free_event_id++;
647 event->instrumentation = itype;
648 event->evtype = LTTNG_TYPE_EVENT;
649 INIT_LIST_HEAD(&event->bytecode_runtime_head);
650 INIT_LIST_HEAD(&event->enablers_ref_head);
651
652 switch (itype) {
653 case LTTNG_KERNEL_TRACEPOINT:
654 /* Event will be enabled by enabler sync. */
655 event->enabled = 0;
656 event->registered = 0;
657 event->desc = lttng_event_get(event_name);
658 if (!event->desc) {
659 ret = -ENOENT;
660 goto register_error;
661 }
662 /* Populate lttng_event structure before event registration. */
663 smp_wmb();
664 break;
665 case LTTNG_KERNEL_KPROBE:
666 /*
667 * Needs to be explicitly enabled after creation, since
668 * we may want to apply filters.
669 */
670 event->enabled = 0;
671 event->registered = 1;
672 /*
673 * Populate lttng_event structure before event
674 * registration.
675 */
676 smp_wmb();
677 ret = lttng_kprobes_register(event_name,
678 event_param->u.kprobe.symbol_name,
679 event_param->u.kprobe.offset,
680 event_param->u.kprobe.addr,
681 event);
682 if (ret) {
683 ret = -EINVAL;
684 goto register_error;
685 }
686 ret = try_module_get(event->desc->owner);
687 WARN_ON_ONCE(!ret);
688 break;
689 case LTTNG_KERNEL_KRETPROBE:
690 {
691 struct lttng_event *event_return;
692
693 /* kretprobe defines 2 events */
694 /*
695 * Needs to be explicitly enabled after creation, since
696 * we may want to apply filters.
697 */
698 event->enabled = 0;
699 event->registered = 1;
700 event_return =
701 kmem_cache_zalloc(event_cache, GFP_KERNEL);
702 if (!event_return) {
703 ret = -ENOMEM;
704 goto register_error;
705 }
706 event_return->chan = chan;
707 event_return->filter = filter;
708 event_return->id = chan->free_event_id++;
709 event_return->enabled = 0;
710 event_return->registered = 1;
711 event_return->instrumentation = itype;
712 INIT_LIST_HEAD(&event_return->bytecode_runtime_head);
713 INIT_LIST_HEAD(&event_return->enablers_ref_head);
714 /*
715 * Populate lttng_event structure before kretprobe registration.
716 */
717 smp_wmb();
718 ret = lttng_kretprobes_register(event_name,
719 event_param->u.kretprobe.symbol_name,
720 event_param->u.kretprobe.offset,
721 event_param->u.kretprobe.addr,
722 event, event_return);
723 if (ret) {
724 kmem_cache_free(event_cache, event_return);
725 ret = -EINVAL;
726 goto register_error;
727 }
728 /* Take 2 refs on the module: one per event. */
729 ret = try_module_get(event->desc->owner);
730 WARN_ON_ONCE(!ret);
731 ret = try_module_get(event->desc->owner);
732 WARN_ON_ONCE(!ret);
733 ret = _lttng_event_metadata_statedump(chan->session, chan,
734 event_return);
735 WARN_ON_ONCE(ret > 0);
736 if (ret) {
737 kmem_cache_free(event_cache, event_return);
738 module_put(event->desc->owner);
739 module_put(event->desc->owner);
740 goto statedump_error;
741 }
742 list_add(&event_return->list, &chan->session->events);
743 break;
744 }
745 case LTTNG_KERNEL_NOOP:
746 case LTTNG_KERNEL_SYSCALL:
747 /*
748 * Needs to be explicitly enabled after creation, since
749 * we may want to apply filters.
750 */
751 event->enabled = 0;
752 event->registered = 0;
753 event->desc = event_desc;
754 switch (event_param->u.syscall.entryexit) {
755 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
756 ret = -EINVAL;
757 goto register_error;
758 case LTTNG_KERNEL_SYSCALL_ENTRY:
759 event->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
760 break;
761 case LTTNG_KERNEL_SYSCALL_EXIT:
762 event->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
763 break;
764 }
765 switch (event_param->u.syscall.abi) {
766 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
767 ret = -EINVAL;
768 goto register_error;
769 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
770 event->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
771 break;
772 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
773 event->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
774 break;
775 }
776 if (!event->desc) {
777 ret = -EINVAL;
778 goto register_error;
779 }
780 break;
781 case LTTNG_KERNEL_UPROBE:
782 /*
783 * Needs to be explicitly enabled after creation, since
784 * we may want to apply filters.
785 */
786 event->enabled = 0;
787 event->registered = 1;
788
789 /*
790 * Populate lttng_event structure before event
791 * registration.
792 */
793 smp_wmb();
794
795 ret = lttng_uprobes_register(event_param->name,
796 event_param->u.uprobe.fd,
797 event);
798 if (ret)
799 goto register_error;
800 ret = try_module_get(event->desc->owner);
801 WARN_ON_ONCE(!ret);
802 break;
803 case LTTNG_KERNEL_FUNCTION:
804 lttng_fallthrough;
805 default:
806 WARN_ON_ONCE(1);
807 ret = -EINVAL;
808 goto register_error;
809 }
810 ret = _lttng_event_metadata_statedump(chan->session, chan, event);
811 WARN_ON_ONCE(ret > 0);
812 if (ret) {
813 goto statedump_error;
814 }
815 hlist_add_head(&event->hlist, head);
816 list_add(&event->list, &chan->session->events);
817 return event;
818
819 statedump_error:
820 /* If a statedump error occurs, events will not be readable. */
821 register_error:
822 kmem_cache_free(event_cache, event);
823 cache_error:
824 exist:
825 type_error:
826 full:
827 return ERR_PTR(ret);
828 }
829
830 struct lttng_event *lttng_event_create(struct lttng_channel *chan,
831 struct lttng_kernel_event *event_param,
832 void *filter,
833 const struct lttng_event_desc *event_desc,
834 enum lttng_kernel_instrumentation itype)
835 {
836 struct lttng_event *event;
837
838 mutex_lock(&sessions_mutex);
839 event = _lttng_event_create(chan, event_param, filter, event_desc,
840 itype);
841 mutex_unlock(&sessions_mutex);
842 return event;
843 }
844
845 /* Only used for tracepoints for now. */
846 static
847 void register_event(struct lttng_event *event)
848 {
849 const struct lttng_event_desc *desc;
850 int ret = -EINVAL;
851
852 if (event->registered)
853 return;
854
855 desc = event->desc;
856 switch (event->instrumentation) {
857 case LTTNG_KERNEL_TRACEPOINT:
858 ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
859 desc->probe_callback,
860 event);
861 break;
862 case LTTNG_KERNEL_SYSCALL:
863 ret = lttng_syscall_filter_enable(event->chan, event);
864 break;
865 case LTTNG_KERNEL_KPROBE:
866 case LTTNG_KERNEL_UPROBE:
867 case LTTNG_KERNEL_KRETPROBE:
868 case LTTNG_KERNEL_NOOP:
869 ret = 0;
870 break;
871 case LTTNG_KERNEL_FUNCTION:
872 lttng_fallthrough;
873 default:
874 WARN_ON_ONCE(1);
875 }
876 if (!ret)
877 event->registered = 1;
878 }
879
880 /*
881 * Only used internally at session destruction.
882 */
883 int _lttng_event_unregister(struct lttng_event *event)
884 {
885 const struct lttng_event_desc *desc;
886 int ret = -EINVAL;
887
888 if (!event->registered)
889 return 0;
890
891 desc = event->desc;
892 switch (event->instrumentation) {
893 case LTTNG_KERNEL_TRACEPOINT:
894 ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname,
895 event->desc->probe_callback,
896 event);
897 break;
898 case LTTNG_KERNEL_KPROBE:
899 lttng_kprobes_unregister(event);
900 ret = 0;
901 break;
902 case LTTNG_KERNEL_KRETPROBE:
903 lttng_kretprobes_unregister(event);
904 ret = 0;
905 break;
906 case LTTNG_KERNEL_SYSCALL:
907 ret = lttng_syscall_filter_disable(event->chan, event);
908 break;
909 case LTTNG_KERNEL_NOOP:
910 ret = 0;
911 break;
912 case LTTNG_KERNEL_UPROBE:
913 lttng_uprobes_unregister(event);
914 ret = 0;
915 break;
916 case LTTNG_KERNEL_FUNCTION:
917 lttng_fallthrough;
918 default:
919 WARN_ON_ONCE(1);
920 }
921 if (!ret)
922 event->registered = 0;
923 return ret;
924 }
925
926 /*
927 * Only used internally at session destruction.
928 */
929 static
930 void _lttng_event_destroy(struct lttng_event *event)
931 {
932 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
933
934 switch (event->instrumentation) {
935 case LTTNG_KERNEL_TRACEPOINT:
936 lttng_event_put(event->desc);
937 break;
938 case LTTNG_KERNEL_KPROBE:
939 module_put(event->desc->owner);
940 lttng_kprobes_destroy_private(event);
941 break;
942 case LTTNG_KERNEL_KRETPROBE:
943 module_put(event->desc->owner);
944 lttng_kretprobes_destroy_private(event);
945 break;
946 case LTTNG_KERNEL_NOOP:
947 case LTTNG_KERNEL_SYSCALL:
948 break;
949 case LTTNG_KERNEL_UPROBE:
950 module_put(event->desc->owner);
951 lttng_uprobes_destroy_private(event);
952 break;
953 case LTTNG_KERNEL_FUNCTION:
954 lttng_fallthrough;
955 default:
956 WARN_ON_ONCE(1);
957 }
958 list_del(&event->list);
959 lttng_destroy_context(event->ctx);
960 lttng_free_event_filter_runtime(event);
961 /* Free event enabler refs */
962 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
963 &event->enablers_ref_head, node)
964 kfree(enabler_ref);
965 kmem_cache_free(event_cache, event);
966 }
967
968 struct lttng_id_tracker *get_tracker(struct lttng_session *session,
969 enum tracker_type tracker_type)
970 {
971 switch (tracker_type) {
972 case TRACKER_PID:
973 return &session->pid_tracker;
974 case TRACKER_VPID:
975 return &session->vpid_tracker;
976 case TRACKER_UID:
977 return &session->uid_tracker;
978 case TRACKER_VUID:
979 return &session->vuid_tracker;
980 case TRACKER_GID:
981 return &session->gid_tracker;
982 case TRACKER_VGID:
983 return &session->vgid_tracker;
984 default:
985 WARN_ON_ONCE(1);
986 return NULL;
987 }
988 }
989
990 int lttng_session_track_id(struct lttng_session *session,
991 enum tracker_type tracker_type, int id)
992 {
993 struct lttng_id_tracker *tracker;
994 int ret;
995
996 tracker = get_tracker(session, tracker_type);
997 if (!tracker)
998 return -EINVAL;
999 if (id < -1)
1000 return -EINVAL;
1001 mutex_lock(&sessions_mutex);
1002 if (id == -1) {
1003 /* track all ids: destroy tracker. */
1004 lttng_id_tracker_destroy(tracker, true);
1005 ret = 0;
1006 } else {
1007 ret = lttng_id_tracker_add(tracker, id);
1008 }
1009 mutex_unlock(&sessions_mutex);
1010 return ret;
1011 }
1012
1013 int lttng_session_untrack_id(struct lttng_session *session,
1014 enum tracker_type tracker_type, int id)
1015 {
1016 struct lttng_id_tracker *tracker;
1017 int ret;
1018
1019 tracker = get_tracker(session, tracker_type);
1020 if (!tracker)
1021 return -EINVAL;
1022 if (id < -1)
1023 return -EINVAL;
1024 mutex_lock(&sessions_mutex);
1025 if (id == -1) {
1026 /* untrack all ids: replace by empty tracker. */
1027 ret = lttng_id_tracker_empty_set(tracker);
1028 } else {
1029 ret = lttng_id_tracker_del(tracker, id);
1030 }
1031 mutex_unlock(&sessions_mutex);
1032 return ret;
1033 }
1034
1035 static
1036 void *id_list_start(struct seq_file *m, loff_t *pos)
1037 {
1038 struct lttng_id_tracker *id_tracker = m->private;
1039 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1040 struct lttng_id_hash_node *e;
1041 int iter = 0, i;
1042
1043 mutex_lock(&sessions_mutex);
1044 if (id_tracker_p) {
1045 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1046 struct hlist_head *head = &id_tracker_p->id_hash[i];
1047
1048 lttng_hlist_for_each_entry(e, head, hlist) {
1049 if (iter++ >= *pos)
1050 return e;
1051 }
1052 }
1053 } else {
1054 /* ID tracker disabled. */
1055 if (iter >= *pos && iter == 0) {
1056 return id_tracker_p; /* empty tracker */
1057 }
1058 iter++;
1059 }
1060 /* End of list */
1061 return NULL;
1062 }
1063
1064 /* Called with sessions_mutex held. */
1065 static
1066 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1067 {
1068 struct lttng_id_tracker *id_tracker = m->private;
1069 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1070 struct lttng_id_hash_node *e;
1071 int iter = 0, i;
1072
1073 (*ppos)++;
1074 if (id_tracker_p) {
1075 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1076 struct hlist_head *head = &id_tracker_p->id_hash[i];
1077
1078 lttng_hlist_for_each_entry(e, head, hlist) {
1079 if (iter++ >= *ppos)
1080 return e;
1081 }
1082 }
1083 } else {
1084 /* ID tracker disabled. */
1085 if (iter >= *ppos && iter == 0)
1086 return p; /* empty tracker */
1087 iter++;
1088 }
1089
1090 /* End of list */
1091 return NULL;
1092 }
1093
1094 static
1095 void id_list_stop(struct seq_file *m, void *p)
1096 {
1097 mutex_unlock(&sessions_mutex);
1098 }
1099
1100 static
1101 int id_list_show(struct seq_file *m, void *p)
1102 {
1103 struct lttng_id_tracker *id_tracker = m->private;
1104 struct lttng_id_tracker_rcu *id_tracker_p = id_tracker->p;
1105 int id;
1106
1107 if (p == id_tracker_p) {
1108 /* Tracker disabled. */
1109 id = -1;
1110 } else {
1111 const struct lttng_id_hash_node *e = p;
1112
1113 id = lttng_id_tracker_get_node_id(e);
1114 }
1115 switch (id_tracker->tracker_type) {
1116 case TRACKER_PID:
1117 seq_printf(m, "process { pid = %d; };\n", id);
1118 break;
1119 case TRACKER_VPID:
1120 seq_printf(m, "process { vpid = %d; };\n", id);
1121 break;
1122 case TRACKER_UID:
1123 seq_printf(m, "user { uid = %d; };\n", id);
1124 break;
1125 case TRACKER_VUID:
1126 seq_printf(m, "user { vuid = %d; };\n", id);
1127 break;
1128 case TRACKER_GID:
1129 seq_printf(m, "group { gid = %d; };\n", id);
1130 break;
1131 case TRACKER_VGID:
1132 seq_printf(m, "group { vgid = %d; };\n", id);
1133 break;
1134 default:
1135 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1136 }
1137 return 0;
1138 }
1139
1140 static
1141 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1142 .start = id_list_start,
1143 .next = id_list_next,
1144 .stop = id_list_stop,
1145 .show = id_list_show,
1146 };
1147
1148 static
1149 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1150 {
1151 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1152 }
1153
1154 static
1155 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1156 {
1157 struct seq_file *m = file->private_data;
1158 struct lttng_id_tracker *id_tracker = m->private;
1159 int ret;
1160
1161 WARN_ON_ONCE(!id_tracker);
1162 ret = seq_release(inode, file);
1163 if (!ret)
1164 fput(id_tracker->session->file);
1165 return ret;
1166 }
1167
1168 const struct file_operations lttng_tracker_ids_list_fops = {
1169 .owner = THIS_MODULE,
1170 .open = lttng_tracker_ids_list_open,
1171 .read = seq_read,
1172 .llseek = seq_lseek,
1173 .release = lttng_tracker_ids_list_release,
1174 };
1175
1176 int lttng_session_list_tracker_ids(struct lttng_session *session,
1177 enum tracker_type tracker_type)
1178 {
1179 struct file *tracker_ids_list_file;
1180 struct seq_file *m;
1181 int file_fd, ret;
1182
1183 file_fd = lttng_get_unused_fd();
1184 if (file_fd < 0) {
1185 ret = file_fd;
1186 goto fd_error;
1187 }
1188
1189 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1190 &lttng_tracker_ids_list_fops,
1191 NULL, O_RDWR);
1192 if (IS_ERR(tracker_ids_list_file)) {
1193 ret = PTR_ERR(tracker_ids_list_file);
1194 goto file_error;
1195 }
1196 if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
1197 ret = -EOVERFLOW;
1198 goto refcount_error;
1199 }
1200 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1201 if (ret < 0)
1202 goto open_error;
1203 m = tracker_ids_list_file->private_data;
1204
1205 m->private = get_tracker(session, tracker_type);
1206 BUG_ON(!m->private);
1207 fd_install(file_fd, tracker_ids_list_file);
1208
1209 return file_fd;
1210
1211 open_error:
1212 atomic_long_dec(&session->file->f_count);
1213 refcount_error:
1214 fput(tracker_ids_list_file);
1215 file_error:
1216 put_unused_fd(file_fd);
1217 fd_error:
1218 return ret;
1219 }
1220
1221 /*
1222 * Enabler management.
1223 */
1224 static
1225 int lttng_match_enabler_star_glob(const char *desc_name,
1226 const char *pattern)
1227 {
1228 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1229 desc_name, LTTNG_SIZE_MAX))
1230 return 0;
1231 return 1;
1232 }
1233
1234 static
1235 int lttng_match_enabler_name(const char *desc_name,
1236 const char *name)
1237 {
1238 if (strcmp(desc_name, name))
1239 return 0;
1240 return 1;
1241 }
1242
1243 static
1244 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
1245 struct lttng_enabler *enabler)
1246 {
1247 const char *desc_name, *enabler_name;
1248 bool compat = false, entry = false;
1249
1250 enabler_name = enabler->event_param.name;
1251 switch (enabler->event_param.instrumentation) {
1252 case LTTNG_KERNEL_TRACEPOINT:
1253 desc_name = desc->name;
1254 switch (enabler->type) {
1255 case LTTNG_ENABLER_STAR_GLOB:
1256 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1257 case LTTNG_ENABLER_NAME:
1258 return lttng_match_enabler_name(desc_name, enabler_name);
1259 default:
1260 return -EINVAL;
1261 }
1262 break;
1263 case LTTNG_KERNEL_SYSCALL:
1264 desc_name = desc->name;
1265 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
1266 desc_name += strlen("compat_");
1267 compat = true;
1268 }
1269 if (!strncmp(desc_name, "syscall_exit_",
1270 strlen("syscall_exit_"))) {
1271 desc_name += strlen("syscall_exit_");
1272 } else if (!strncmp(desc_name, "syscall_entry_",
1273 strlen("syscall_entry_"))) {
1274 desc_name += strlen("syscall_entry_");
1275 entry = true;
1276 } else {
1277 WARN_ON_ONCE(1);
1278 return -EINVAL;
1279 }
1280 switch (enabler->event_param.u.syscall.entryexit) {
1281 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1282 break;
1283 case LTTNG_KERNEL_SYSCALL_ENTRY:
1284 if (!entry)
1285 return 0;
1286 break;
1287 case LTTNG_KERNEL_SYSCALL_EXIT:
1288 if (entry)
1289 return 0;
1290 break;
1291 default:
1292 return -EINVAL;
1293 }
1294 switch (enabler->event_param.u.syscall.abi) {
1295 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1296 break;
1297 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
1298 if (compat)
1299 return 0;
1300 break;
1301 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
1302 if (!compat)
1303 return 0;
1304 break;
1305 default:
1306 return -EINVAL;
1307 }
1308 switch (enabler->event_param.u.syscall.match) {
1309 case LTTNG_SYSCALL_MATCH_NAME:
1310 switch (enabler->type) {
1311 case LTTNG_ENABLER_STAR_GLOB:
1312 return lttng_match_enabler_star_glob(desc_name, enabler_name);
1313 case LTTNG_ENABLER_NAME:
1314 return lttng_match_enabler_name(desc_name, enabler_name);
1315 default:
1316 return -EINVAL;
1317 }
1318 break;
1319 case LTTNG_SYSCALL_MATCH_NR:
1320 return -EINVAL; /* Not implemented. */
1321 default:
1322 return -EINVAL;
1323 }
1324 break;
1325 default:
1326 WARN_ON_ONCE(1);
1327 return -EINVAL;
1328 }
1329 }
1330
1331 static
1332 int lttng_event_match_enabler(struct lttng_event *event,
1333 struct lttng_enabler *enabler)
1334 {
1335 if (enabler->event_param.instrumentation != event->instrumentation)
1336 return 0;
1337 if (lttng_desc_match_enabler(event->desc, enabler)
1338 && event->chan == enabler->chan)
1339 return 1;
1340 else
1341 return 0;
1342 }
1343
1344 static
1345 struct lttng_enabler_ref *lttng_event_enabler_ref(struct lttng_event *event,
1346 struct lttng_enabler *enabler)
1347 {
1348 struct lttng_enabler_ref *enabler_ref;
1349
1350 list_for_each_entry(enabler_ref,
1351 &event->enablers_ref_head, node) {
1352 if (enabler_ref->ref == enabler)
1353 return enabler_ref;
1354 }
1355 return NULL;
1356 }
1357
1358 static
1359 void lttng_create_tracepoint_if_missing(struct lttng_enabler *enabler)
1360 {
1361 struct lttng_session *session = enabler->chan->session;
1362 struct lttng_probe_desc *probe_desc;
1363 const struct lttng_event_desc *desc;
1364 int i;
1365 struct list_head *probe_list;
1366
1367 probe_list = lttng_get_probe_list_head();
1368 /*
1369 * For each probe event, if we find that a probe event matches
1370 * our enabler, create an associated lttng_event if not
1371 * already present.
1372 */
1373 list_for_each_entry(probe_desc, probe_list, head) {
1374 for (i = 0; i < probe_desc->nr_events; i++) {
1375 int found = 0;
1376 struct hlist_head *head;
1377 const char *event_name;
1378 size_t name_len;
1379 uint32_t hash;
1380 struct lttng_event *event;
1381
1382 desc = probe_desc->event_desc[i];
1383 if (!lttng_desc_match_enabler(desc, enabler))
1384 continue;
1385 event_name = desc->name;
1386 name_len = strlen(event_name);
1387
1388 /*
1389 * Check if already created.
1390 */
1391 hash = jhash(event_name, name_len, 0);
1392 head = &session->events_ht.table[hash & (LTTNG_EVENT_HT_SIZE - 1)];
1393 lttng_hlist_for_each_entry(event, head, hlist) {
1394 if (event->desc == desc
1395 && event->chan == enabler->chan)
1396 found = 1;
1397 }
1398 if (found)
1399 continue;
1400
1401 /*
1402 * We need to create an event for this
1403 * event probe.
1404 */
1405 event = _lttng_event_create(enabler->chan,
1406 NULL, NULL, desc,
1407 LTTNG_KERNEL_TRACEPOINT);
1408 if (!event) {
1409 printk(KERN_INFO "Unable to create event %s\n",
1410 probe_desc->event_desc[i]->name);
1411 }
1412 }
1413 }
1414 }
1415
1416 static
1417 void lttng_create_syscall_if_missing(struct lttng_enabler *enabler)
1418 {
1419 int ret;
1420
1421 ret = lttng_syscalls_register(enabler->chan, NULL);
1422 WARN_ON_ONCE(ret);
1423 }
1424
1425 /*
1426 * Create struct lttng_event if it is missing and present in the list of
1427 * tracepoint probes.
1428 * Should be called with sessions mutex held.
1429 */
1430 static
1431 void lttng_create_event_if_missing(struct lttng_enabler *enabler)
1432 {
1433 switch (enabler->event_param.instrumentation) {
1434 case LTTNG_KERNEL_TRACEPOINT:
1435 lttng_create_tracepoint_if_missing(enabler);
1436 break;
1437 case LTTNG_KERNEL_SYSCALL:
1438 lttng_create_syscall_if_missing(enabler);
1439 break;
1440 default:
1441 WARN_ON_ONCE(1);
1442 break;
1443 }
1444 }
1445
1446 /*
1447 * Create events associated with an enabler (if not already present),
1448 * and add backward reference from the event to the enabler.
1449 * Should be called with sessions mutex held.
1450 */
1451 static
1452 int lttng_enabler_ref_events(struct lttng_enabler *enabler)
1453 {
1454 struct lttng_channel *chan = enabler->chan;
1455 struct lttng_session *session = chan->session;
1456 struct lttng_event *event;
1457
1458 if (enabler->event_param.instrumentation == LTTNG_KERNEL_SYSCALL &&
1459 enabler->event_param.u.syscall.entryexit == LTTNG_KERNEL_SYSCALL_ENTRYEXIT &&
1460 enabler->event_param.u.syscall.abi == LTTNG_KERNEL_SYSCALL_ABI_ALL &&
1461 enabler->event_param.u.syscall.match == LTTNG_SYSCALL_MATCH_NAME &&
1462 !strcmp(enabler->event_param.name, "*")) {
1463 if (enabler->enabled)
1464 WRITE_ONCE(chan->syscall_all, 1);
1465 else
1466 WRITE_ONCE(chan->syscall_all, 0);
1467 }
1468
1469 /* First ensure that probe events are created for this enabler. */
1470 lttng_create_event_if_missing(enabler);
1471
1472 /* For each event matching enabler in session event list. */
1473 list_for_each_entry(event, &session->events, list) {
1474 struct lttng_enabler_ref *enabler_ref;
1475
1476 if (!lttng_event_match_enabler(event, enabler))
1477 continue;
1478 enabler_ref = lttng_event_enabler_ref(event, enabler);
1479 if (!enabler_ref) {
1480 /*
1481 * If no backward ref, create it.
1482 * Add backward ref from event to enabler.
1483 */
1484 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
1485 if (!enabler_ref)
1486 return -ENOMEM;
1487 enabler_ref->ref = enabler;
1488 list_add(&enabler_ref->node,
1489 &event->enablers_ref_head);
1490 }
1491
1492 /*
1493 * Link filter bytecodes if not linked yet.
1494 */
1495 lttng_enabler_event_link_bytecode(event, enabler);
1496
1497 /* TODO: merge event context. */
1498 }
1499 return 0;
1500 }
1501
1502 /*
1503 * Called at module load: connect the probe on all enablers matching
1504 * this event.
1505 * Called with sessions lock held.
1506 */
1507 int lttng_fix_pending_events(void)
1508 {
1509 struct lttng_session *session;
1510
1511 list_for_each_entry(session, &sessions, list)
1512 lttng_session_lazy_sync_enablers(session);
1513 return 0;
1514 }
1515
1516 struct lttng_enabler *lttng_enabler_create(enum lttng_enabler_type type,
1517 struct lttng_kernel_event *event_param,
1518 struct lttng_channel *chan)
1519 {
1520 struct lttng_enabler *enabler;
1521
1522 enabler = kzalloc(sizeof(*enabler), GFP_KERNEL);
1523 if (!enabler)
1524 return NULL;
1525 enabler->type = type;
1526 INIT_LIST_HEAD(&enabler->filter_bytecode_head);
1527 memcpy(&enabler->event_param, event_param,
1528 sizeof(enabler->event_param));
1529 enabler->chan = chan;
1530 /* ctx left NULL */
1531 enabler->enabled = 0;
1532 enabler->evtype = LTTNG_TYPE_ENABLER;
1533 mutex_lock(&sessions_mutex);
1534 list_add(&enabler->node, &enabler->chan->session->enablers_head);
1535 lttng_session_lazy_sync_enablers(enabler->chan->session);
1536 mutex_unlock(&sessions_mutex);
1537 return enabler;
1538 }
1539
1540 int lttng_enabler_enable(struct lttng_enabler *enabler)
1541 {
1542 mutex_lock(&sessions_mutex);
1543 enabler->enabled = 1;
1544 lttng_session_lazy_sync_enablers(enabler->chan->session);
1545 mutex_unlock(&sessions_mutex);
1546 return 0;
1547 }
1548
1549 int lttng_enabler_disable(struct lttng_enabler *enabler)
1550 {
1551 mutex_lock(&sessions_mutex);
1552 enabler->enabled = 0;
1553 lttng_session_lazy_sync_enablers(enabler->chan->session);
1554 mutex_unlock(&sessions_mutex);
1555 return 0;
1556 }
1557
1558 int lttng_enabler_attach_bytecode(struct lttng_enabler *enabler,
1559 struct lttng_kernel_filter_bytecode __user *bytecode)
1560 {
1561 struct lttng_filter_bytecode_node *bytecode_node;
1562 uint32_t bytecode_len;
1563 int ret;
1564
1565 ret = get_user(bytecode_len, &bytecode->len);
1566 if (ret)
1567 return ret;
1568 bytecode_node = kzalloc(sizeof(*bytecode_node) + bytecode_len,
1569 GFP_KERNEL);
1570 if (!bytecode_node)
1571 return -ENOMEM;
1572 ret = copy_from_user(&bytecode_node->bc, bytecode,
1573 sizeof(*bytecode) + bytecode_len);
1574 if (ret)
1575 goto error_free;
1576 bytecode_node->enabler = enabler;
1577 /* Enforce length based on allocated size */
1578 bytecode_node->bc.len = bytecode_len;
1579 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
1580 lttng_session_lazy_sync_enablers(enabler->chan->session);
1581 return 0;
1582
1583 error_free:
1584 kfree(bytecode_node);
1585 return ret;
1586 }
1587
1588 int lttng_event_add_callsite(struct lttng_event *event,
1589 struct lttng_kernel_event_callsite __user *callsite)
1590 {
1591
1592 switch (event->instrumentation) {
1593 case LTTNG_KERNEL_UPROBE:
1594 return lttng_uprobes_add_callsite(event, callsite);
1595 default:
1596 return -EINVAL;
1597 }
1598 }
1599
1600 int lttng_enabler_attach_context(struct lttng_enabler *enabler,
1601 struct lttng_kernel_context *context_param)
1602 {
1603 return -ENOSYS;
1604 }
1605
1606 static
1607 void lttng_enabler_destroy(struct lttng_enabler *enabler)
1608 {
1609 struct lttng_filter_bytecode_node *filter_node, *tmp_filter_node;
1610
1611 /* Destroy filter bytecode */
1612 list_for_each_entry_safe(filter_node, tmp_filter_node,
1613 &enabler->filter_bytecode_head, node) {
1614 kfree(filter_node);
1615 }
1616
1617 /* Destroy contexts */
1618 lttng_destroy_context(enabler->ctx);
1619
1620 list_del(&enabler->node);
1621 kfree(enabler);
1622 }
1623
1624 /*
1625 * lttng_session_sync_enablers should be called just before starting a
1626 * session.
1627 * Should be called with sessions mutex held.
1628 */
1629 static
1630 void lttng_session_sync_enablers(struct lttng_session *session)
1631 {
1632 struct lttng_enabler *enabler;
1633 struct lttng_event *event;
1634
1635 list_for_each_entry(enabler, &session->enablers_head, node)
1636 lttng_enabler_ref_events(enabler);
1637 /*
1638 * For each event, if at least one of its enablers is enabled,
1639 * and its channel and session transient states are enabled, we
1640 * enable the event, else we disable it.
1641 */
1642 list_for_each_entry(event, &session->events, list) {
1643 struct lttng_enabler_ref *enabler_ref;
1644 struct lttng_bytecode_runtime *runtime;
1645 int enabled = 0, has_enablers_without_bytecode = 0;
1646
1647 switch (event->instrumentation) {
1648 case LTTNG_KERNEL_TRACEPOINT:
1649 case LTTNG_KERNEL_SYSCALL:
1650 /* Enable events */
1651 list_for_each_entry(enabler_ref,
1652 &event->enablers_ref_head, node) {
1653 if (enabler_ref->ref->enabled) {
1654 enabled = 1;
1655 break;
1656 }
1657 }
1658 break;
1659 default:
1660 /* Not handled with lazy sync. */
1661 continue;
1662 }
1663 /*
1664 * Enabled state is based on union of enablers, with
1665 * intesection of session and channel transient enable
1666 * states.
1667 */
1668 enabled = enabled && session->tstate && event->chan->tstate;
1669
1670 WRITE_ONCE(event->enabled, enabled);
1671 /*
1672 * Sync tracepoint registration with event enabled
1673 * state.
1674 */
1675 if (enabled) {
1676 register_event(event);
1677 } else {
1678 _lttng_event_unregister(event);
1679 }
1680
1681 /* Check if has enablers without bytecode enabled */
1682 list_for_each_entry(enabler_ref,
1683 &event->enablers_ref_head, node) {
1684 if (enabler_ref->ref->enabled
1685 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
1686 has_enablers_without_bytecode = 1;
1687 break;
1688 }
1689 }
1690 event->has_enablers_without_bytecode =
1691 has_enablers_without_bytecode;
1692
1693 /* Enable filters */
1694 list_for_each_entry(runtime,
1695 &event->bytecode_runtime_head, node)
1696 lttng_filter_sync_state(runtime);
1697 }
1698 }
1699
1700 /*
1701 * Apply enablers to session events, adding events to session if need
1702 * be. It is required after each modification applied to an active
1703 * session, and right before session "start".
1704 * "lazy" sync means we only sync if required.
1705 * Should be called with sessions mutex held.
1706 */
1707 static
1708 void lttng_session_lazy_sync_enablers(struct lttng_session *session)
1709 {
1710 /* We can skip if session is not active */
1711 if (!session->active)
1712 return;
1713 lttng_session_sync_enablers(session);
1714 }
1715
1716 /*
1717 * Serialize at most one packet worth of metadata into a metadata
1718 * channel.
1719 * We grab the metadata cache mutex to get exclusive access to our metadata
1720 * buffer and to the metadata cache. Exclusive access to the metadata buffer
1721 * allows us to do racy operations such as looking for remaining space left in
1722 * packet and write, since mutual exclusion protects us from concurrent writes.
1723 * Mutual exclusion on the metadata cache allow us to read the cache content
1724 * without racing against reallocation of the cache by updates.
1725 * Returns the number of bytes written in the channel, 0 if no data
1726 * was written and a negative value on error.
1727 */
1728 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
1729 struct channel *chan, bool *coherent)
1730 {
1731 struct lib_ring_buffer_ctx ctx;
1732 int ret = 0;
1733 size_t len, reserve_len;
1734
1735 /*
1736 * Ensure we support mutiple get_next / put sequences followed by
1737 * put_next. The metadata cache lock protects reading the metadata
1738 * cache. It can indeed be read concurrently by "get_next_subbuf" and
1739 * "flush" operations on the buffer invoked by different processes.
1740 * Moreover, since the metadata cache memory can be reallocated, we
1741 * need to have exclusive access against updates even though we only
1742 * read it.
1743 */
1744 mutex_lock(&stream->metadata_cache->lock);
1745 WARN_ON(stream->metadata_in < stream->metadata_out);
1746 if (stream->metadata_in != stream->metadata_out)
1747 goto end;
1748
1749 /* Metadata regenerated, change the version. */
1750 if (stream->metadata_cache->version != stream->version)
1751 stream->version = stream->metadata_cache->version;
1752
1753 len = stream->metadata_cache->metadata_written -
1754 stream->metadata_in;
1755 if (!len)
1756 goto end;
1757 reserve_len = min_t(size_t,
1758 stream->transport->ops.packet_avail_size(chan),
1759 len);
1760 lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
1761 sizeof(char), -1);
1762 /*
1763 * If reservation failed, return an error to the caller.
1764 */
1765 ret = stream->transport->ops.event_reserve(&ctx, 0);
1766 if (ret != 0) {
1767 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
1768 stream->coherent = false;
1769 goto end;
1770 }
1771 stream->transport->ops.event_write(&ctx,
1772 stream->metadata_cache->data + stream->metadata_in,
1773 reserve_len);
1774 stream->transport->ops.event_commit(&ctx);
1775 stream->metadata_in += reserve_len;
1776 if (reserve_len < len)
1777 stream->coherent = false;
1778 else
1779 stream->coherent = true;
1780 ret = reserve_len;
1781
1782 end:
1783 if (coherent)
1784 *coherent = stream->coherent;
1785 mutex_unlock(&stream->metadata_cache->lock);
1786 return ret;
1787 }
1788
1789 static
1790 void lttng_metadata_begin(struct lttng_session *session)
1791 {
1792 if (atomic_inc_return(&session->metadata_cache->producing) == 1)
1793 mutex_lock(&session->metadata_cache->lock);
1794 }
1795
1796 static
1797 void lttng_metadata_end(struct lttng_session *session)
1798 {
1799 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
1800 if (atomic_dec_return(&session->metadata_cache->producing) == 0) {
1801 struct lttng_metadata_stream *stream;
1802
1803 list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
1804 wake_up_interruptible(&stream->read_wait);
1805 mutex_unlock(&session->metadata_cache->lock);
1806 }
1807 }
1808
1809 /*
1810 * Write the metadata to the metadata cache.
1811 * Must be called with sessions_mutex held.
1812 * The metadata cache lock protects us from concurrent read access from
1813 * thread outputting metadata content to ring buffer.
1814 * The content of the printf is printed as a single atomic metadata
1815 * transaction.
1816 */
1817 int lttng_metadata_printf(struct lttng_session *session,
1818 const char *fmt, ...)
1819 {
1820 char *str;
1821 size_t len;
1822 va_list ap;
1823
1824 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
1825
1826 va_start(ap, fmt);
1827 str = kvasprintf(GFP_KERNEL, fmt, ap);
1828 va_end(ap);
1829 if (!str)
1830 return -ENOMEM;
1831
1832 len = strlen(str);
1833 WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
1834 if (session->metadata_cache->metadata_written + len >
1835 session->metadata_cache->cache_alloc) {
1836 char *tmp_cache_realloc;
1837 unsigned int tmp_cache_alloc_size;
1838
1839 tmp_cache_alloc_size = max_t(unsigned int,
1840 session->metadata_cache->cache_alloc + len,
1841 session->metadata_cache->cache_alloc << 1);
1842 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
1843 if (!tmp_cache_realloc)
1844 goto err;
1845 if (session->metadata_cache->data) {
1846 memcpy(tmp_cache_realloc,
1847 session->metadata_cache->data,
1848 session->metadata_cache->cache_alloc);
1849 vfree(session->metadata_cache->data);
1850 }
1851
1852 session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
1853 session->metadata_cache->data = tmp_cache_realloc;
1854 }
1855 memcpy(session->metadata_cache->data +
1856 session->metadata_cache->metadata_written,
1857 str, len);
1858 session->metadata_cache->metadata_written += len;
1859 kfree(str);
1860
1861 return 0;
1862
1863 err:
1864 kfree(str);
1865 return -ENOMEM;
1866 }
1867
1868 static
1869 int print_tabs(struct lttng_session *session, size_t nesting)
1870 {
1871 size_t i;
1872
1873 for (i = 0; i < nesting; i++) {
1874 int ret;
1875
1876 ret = lttng_metadata_printf(session, " ");
1877 if (ret) {
1878 return ret;
1879 }
1880 }
1881 return 0;
1882 }
1883
1884 /*
1885 * Must be called with sessions_mutex held.
1886 */
1887 static
1888 int _lttng_struct_type_statedump(struct lttng_session *session,
1889 const struct lttng_type *type,
1890 size_t nesting)
1891 {
1892 int ret;
1893 uint32_t i, nr_fields;
1894
1895 ret = print_tabs(session, nesting);
1896 if (ret)
1897 return ret;
1898 ret = lttng_metadata_printf(session,
1899 "struct {\n");
1900 if (ret)
1901 return ret;
1902 nr_fields = type->u._struct.nr_fields;
1903 for (i = 0; i < nr_fields; i++) {
1904 const struct lttng_event_field *iter_field;
1905
1906 iter_field = &type->u._struct.fields[i];
1907 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
1908 if (ret)
1909 return ret;
1910 }
1911 ret = print_tabs(session, nesting);
1912 if (ret)
1913 return ret;
1914 ret = lttng_metadata_printf(session,
1915 "}");
1916 return ret;
1917 }
1918
1919 /*
1920 * Must be called with sessions_mutex held.
1921 */
1922 static
1923 int _lttng_struct_statedump(struct lttng_session *session,
1924 const struct lttng_event_field *field,
1925 size_t nesting)
1926 {
1927 int ret;
1928
1929 ret = _lttng_struct_type_statedump(session,
1930 &field->type, nesting);
1931 if (ret)
1932 return ret;
1933 ret = lttng_metadata_printf(session,
1934 "_%s;\n",
1935 field->name);
1936 return ret;
1937 }
1938
1939 /*
1940 * Must be called with sessions_mutex held.
1941 */
1942 static
1943 int _lttng_variant_type_statedump(struct lttng_session *session,
1944 const struct lttng_type *type,
1945 size_t nesting)
1946 {
1947 int ret;
1948 uint32_t i, nr_choices;
1949
1950 ret = print_tabs(session, nesting);
1951 if (ret)
1952 return ret;
1953 ret = lttng_metadata_printf(session,
1954 "variant <_%s> {\n",
1955 type->u.variant.tag_name);
1956 if (ret)
1957 return ret;
1958 nr_choices = type->u.variant.nr_choices;
1959 for (i = 0; i < nr_choices; i++) {
1960 const struct lttng_event_field *iter_field;
1961
1962 iter_field = &type->u.variant.choices[i];
1963 ret = _lttng_field_statedump(session, iter_field, nesting + 1);
1964 if (ret)
1965 return ret;
1966 }
1967 ret = print_tabs(session, nesting);
1968 if (ret)
1969 return ret;
1970 ret = lttng_metadata_printf(session,
1971 "}");
1972 return ret;
1973 }
1974
1975 /*
1976 * Must be called with sessions_mutex held.
1977 */
1978 static
1979 int _lttng_variant_statedump(struct lttng_session *session,
1980 const struct lttng_event_field *field,
1981 size_t nesting)
1982 {
1983 int ret;
1984
1985 ret = _lttng_variant_type_statedump(session,
1986 &field->type, nesting);
1987 if (ret)
1988 return ret;
1989 ret = lttng_metadata_printf(session,
1990 "_%s;\n",
1991 field->name);
1992 return ret;
1993 }
1994
1995 /*
1996 * Must be called with sessions_mutex held.
1997 */
1998 static
1999 int _lttng_array_compound_statedump(struct lttng_session *session,
2000 const struct lttng_event_field *field,
2001 size_t nesting)
2002 {
2003 int ret;
2004 const struct lttng_type *elem_type;
2005
2006 /* Only array of structures and variants are currently supported. */
2007 elem_type = field->type.u.array_compound.elem_type;
2008 switch (elem_type->atype) {
2009 case atype_struct:
2010 ret = _lttng_struct_type_statedump(session, elem_type, nesting);
2011 if (ret)
2012 return ret;
2013 break;
2014 case atype_variant:
2015 ret = _lttng_variant_type_statedump(session, elem_type, nesting);
2016 if (ret)
2017 return ret;
2018 break;
2019 default:
2020 return -EINVAL;
2021 }
2022 ret = lttng_metadata_printf(session,
2023 " _%s[%u];\n",
2024 field->name,
2025 field->type.u.array_compound.length);
2026 return ret;
2027 }
2028
2029 /*
2030 * Must be called with sessions_mutex held.
2031 */
2032 static
2033 int _lttng_sequence_compound_statedump(struct lttng_session *session,
2034 const struct lttng_event_field *field,
2035 size_t nesting)
2036 {
2037 int ret;
2038 const char *length_name;
2039 const struct lttng_type *elem_type;
2040
2041 length_name = field->type.u.sequence_compound.length_name;
2042
2043 /* Only array of structures and variants are currently supported. */
2044 elem_type = field->type.u.sequence_compound.elem_type;
2045 switch (elem_type->atype) {
2046 case atype_struct:
2047 ret = _lttng_struct_type_statedump(session, elem_type, nesting);
2048 if (ret)
2049 return ret;
2050 break;
2051 case atype_variant:
2052 ret = _lttng_variant_type_statedump(session, elem_type, nesting);
2053 if (ret)
2054 return ret;
2055 break;
2056 default:
2057 return -EINVAL;
2058 }
2059 ret = lttng_metadata_printf(session,
2060 " _%s[ _%s ];\n",
2061 field->name,
2062 length_name);
2063 return ret;
2064 }
2065
2066 /*
2067 * Must be called with sessions_mutex held.
2068 */
2069 static
2070 int _lttng_enum_statedump(struct lttng_session *session,
2071 const struct lttng_event_field *field,
2072 size_t nesting)
2073 {
2074 const struct lttng_enum_desc *enum_desc;
2075 const struct lttng_integer_type *container_type;
2076 int ret;
2077 unsigned int i, nr_entries;
2078
2079 enum_desc = field->type.u.basic.enumeration.desc;
2080 container_type = &field->type.u.basic.enumeration.container_type;
2081 nr_entries = enum_desc->nr_entries;
2082
2083 ret = print_tabs(session, nesting);
2084 if (ret)
2085 goto end;
2086 ret = lttng_metadata_printf(session,
2087 "enum : integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } {\n",
2088 container_type->size,
2089 container_type->alignment,
2090 container_type->signedness,
2091 (container_type->encoding == lttng_encode_none)
2092 ? "none"
2093 : (container_type->encoding == lttng_encode_UTF8)
2094 ? "UTF8"
2095 : "ASCII",
2096 container_type->base,
2097 #if __BYTE_ORDER == __BIG_ENDIAN
2098 container_type->reverse_byte_order ? " byte_order = le;" : ""
2099 #else
2100 container_type->reverse_byte_order ? " byte_order = be;" : ""
2101 #endif
2102 );
2103 if (ret)
2104 goto end;
2105 /* Dump all entries */
2106 for (i = 0; i < nr_entries; i++) {
2107 const struct lttng_enum_entry *entry = &enum_desc->entries[i];
2108 int j, len;
2109
2110 ret = print_tabs(session, nesting + 1);
2111 if (ret)
2112 goto end;
2113 ret = lttng_metadata_printf(session,
2114 "\"");
2115 if (ret)
2116 goto end;
2117 len = strlen(entry->string);
2118 /* Escape the character '"' */
2119 for (j = 0; j < len; j++) {
2120 char c = entry->string[j];
2121
2122 switch (c) {
2123 case '"':
2124 ret = lttng_metadata_printf(session,
2125 "\\\"");
2126 break;
2127 case '\\':
2128 ret = lttng_metadata_printf(session,
2129 "\\\\");
2130 break;
2131 default:
2132 ret = lttng_metadata_printf(session,
2133 "%c", c);
2134 break;
2135 }
2136 if (ret)
2137 goto end;
2138 }
2139 ret = lttng_metadata_printf(session, "\"");
2140 if (ret)
2141 goto end;
2142
2143 if (entry->options.is_auto) {
2144 ret = lttng_metadata_printf(session, ",\n");
2145 if (ret)
2146 goto end;
2147 } else {
2148 ret = lttng_metadata_printf(session,
2149 " = ");
2150 if (ret)
2151 goto end;
2152 if (entry->start.signedness)
2153 ret = lttng_metadata_printf(session,
2154 "%lld", (long long) entry->start.value);
2155 else
2156 ret = lttng_metadata_printf(session,
2157 "%llu", entry->start.value);
2158 if (ret)
2159 goto end;
2160 if (entry->start.signedness == entry->end.signedness &&
2161 entry->start.value
2162 == entry->end.value) {
2163 ret = lttng_metadata_printf(session,
2164 ",\n");
2165 } else {
2166 if (entry->end.signedness) {
2167 ret = lttng_metadata_printf(session,
2168 " ... %lld,\n",
2169 (long long) entry->end.value);
2170 } else {
2171 ret = lttng_metadata_printf(session,
2172 " ... %llu,\n",
2173 entry->end.value);
2174 }
2175 }
2176 if (ret)
2177 goto end;
2178 }
2179 }
2180 ret = print_tabs(session, nesting);
2181 if (ret)
2182 goto end;
2183 ret = lttng_metadata_printf(session, "} _%s;\n",
2184 field->name);
2185 end:
2186 return ret;
2187 }
2188
2189 /*
2190 * Must be called with sessions_mutex held.
2191 */
2192 static
2193 int _lttng_field_statedump(struct lttng_session *session,
2194 const struct lttng_event_field *field,
2195 size_t nesting)
2196 {
2197 int ret = 0;
2198
2199 switch (field->type.atype) {
2200 case atype_integer:
2201 ret = print_tabs(session, nesting);
2202 if (ret)
2203 return ret;
2204 ret = lttng_metadata_printf(session,
2205 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
2206 field->type.u.basic.integer.size,
2207 field->type.u.basic.integer.alignment,
2208 field->type.u.basic.integer.signedness,
2209 (field->type.u.basic.integer.encoding == lttng_encode_none)
2210 ? "none"
2211 : (field->type.u.basic.integer.encoding == lttng_encode_UTF8)
2212 ? "UTF8"
2213 : "ASCII",
2214 field->type.u.basic.integer.base,
2215 #if __BYTE_ORDER == __BIG_ENDIAN
2216 field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2217 #else
2218 field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2219 #endif
2220 field->name);
2221 break;
2222 case atype_enum:
2223 ret = _lttng_enum_statedump(session, field, nesting);
2224 break;
2225 case atype_array:
2226 case atype_array_bitfield:
2227 {
2228 const struct lttng_basic_type *elem_type;
2229
2230 elem_type = &field->type.u.array.elem_type;
2231 if (field->type.u.array.elem_alignment) {
2232 ret = print_tabs(session, nesting);
2233 if (ret)
2234 return ret;
2235 ret = lttng_metadata_printf(session,
2236 "struct { } align(%u) _%s_padding;\n",
2237 field->type.u.array.elem_alignment * CHAR_BIT,
2238 field->name);
2239 if (ret)
2240 return ret;
2241 }
2242 ret = print_tabs(session, nesting);
2243 if (ret)
2244 return ret;
2245 ret = lttng_metadata_printf(session,
2246 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
2247 elem_type->u.basic.integer.size,
2248 elem_type->u.basic.integer.alignment,
2249 elem_type->u.basic.integer.signedness,
2250 (elem_type->u.basic.integer.encoding == lttng_encode_none)
2251 ? "none"
2252 : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
2253 ? "UTF8"
2254 : "ASCII",
2255 elem_type->u.basic.integer.base,
2256 #if __BYTE_ORDER == __BIG_ENDIAN
2257 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2258 #else
2259 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2260 #endif
2261 field->name, field->type.u.array.length);
2262 break;
2263 }
2264 case atype_sequence:
2265 case atype_sequence_bitfield:
2266 {
2267 const struct lttng_basic_type *elem_type;
2268 const struct lttng_basic_type *length_type;
2269
2270 elem_type = &field->type.u.sequence.elem_type;
2271 length_type = &field->type.u.sequence.length_type;
2272 ret = print_tabs(session, nesting);
2273 if (ret)
2274 return ret;
2275 ret = lttng_metadata_printf(session,
2276 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
2277 length_type->u.basic.integer.size,
2278 (unsigned int) length_type->u.basic.integer.alignment,
2279 length_type->u.basic.integer.signedness,
2280 (length_type->u.basic.integer.encoding == lttng_encode_none)
2281 ? "none"
2282 : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8)
2283 ? "UTF8"
2284 : "ASCII"),
2285 length_type->u.basic.integer.base,
2286 #if __BYTE_ORDER == __BIG_ENDIAN
2287 length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2288 #else
2289 length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2290 #endif
2291 field->name);
2292 if (ret)
2293 return ret;
2294
2295 if (field->type.u.sequence.elem_alignment) {
2296 ret = print_tabs(session, nesting);
2297 if (ret)
2298 return ret;
2299 ret = lttng_metadata_printf(session,
2300 "struct { } align(%u) _%s_padding;\n",
2301 field->type.u.sequence.elem_alignment * CHAR_BIT,
2302 field->name);
2303 if (ret)
2304 return ret;
2305 }
2306 ret = print_tabs(session, nesting);
2307 if (ret)
2308 return ret;
2309 ret = lttng_metadata_printf(session,
2310 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
2311 elem_type->u.basic.integer.size,
2312 (unsigned int) elem_type->u.basic.integer.alignment,
2313 elem_type->u.basic.integer.signedness,
2314 (elem_type->u.basic.integer.encoding == lttng_encode_none)
2315 ? "none"
2316 : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
2317 ? "UTF8"
2318 : "ASCII"),
2319 elem_type->u.basic.integer.base,
2320 #if __BYTE_ORDER == __BIG_ENDIAN
2321 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
2322 #else
2323 elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
2324 #endif
2325 field->name,
2326 field->name);
2327 break;
2328 }
2329
2330 case atype_string:
2331 /* Default encoding is UTF8 */
2332 ret = print_tabs(session, nesting);
2333 if (ret)
2334 return ret;
2335 ret = lttng_metadata_printf(session,
2336 "string%s _%s;\n",
2337 field->type.u.basic.string.encoding == lttng_encode_ASCII ?
2338 " { encoding = ASCII; }" : "",
2339 field->name);
2340 break;
2341 case atype_struct:
2342 ret = _lttng_struct_statedump(session, field, nesting);
2343 break;
2344 case atype_array_compound:
2345 ret = _lttng_array_compound_statedump(session, field, nesting);
2346 break;
2347 case atype_sequence_compound:
2348 ret = _lttng_sequence_compound_statedump(session, field, nesting);
2349 break;
2350 case atype_variant:
2351 ret = _lttng_variant_statedump(session, field, nesting);
2352 break;
2353
2354 default:
2355 WARN_ON_ONCE(1);
2356 return -EINVAL;
2357 }
2358 return ret;
2359 }
2360
2361 static
2362 int _lttng_context_metadata_statedump(struct lttng_session *session,
2363 struct lttng_ctx *ctx)
2364 {
2365 int ret = 0;
2366 int i;
2367
2368 if (!ctx)
2369 return 0;
2370 for (i = 0; i < ctx->nr_fields; i++) {
2371 const struct lttng_ctx_field *field = &ctx->fields[i];
2372
2373 ret = _lttng_field_statedump(session, &field->event_field, 2);
2374 if (ret)
2375 return ret;
2376 }
2377 return ret;
2378 }
2379
2380 static
2381 int _lttng_fields_metadata_statedump(struct lttng_session *session,
2382 struct lttng_event *event)
2383 {
2384 const struct lttng_event_desc *desc = event->desc;
2385 int ret = 0;
2386 int i;
2387
2388 for (i = 0; i < desc->nr_fields; i++) {
2389 const struct lttng_event_field *field = &desc->fields[i];
2390
2391 ret = _lttng_field_statedump(session, field, 2);
2392 if (ret)
2393 return ret;
2394 }
2395 return ret;
2396 }
2397
2398 /*
2399 * Must be called with sessions_mutex held.
2400 * The entire event metadata is printed as a single atomic metadata
2401 * transaction.
2402 */
2403 static
2404 int _lttng_event_metadata_statedump(struct lttng_session *session,
2405 struct lttng_channel *chan,
2406 struct lttng_event *event)
2407 {
2408 int ret = 0;
2409
2410 if (event->metadata_dumped || !LTTNG_READ_ONCE(session->active))
2411 return 0;
2412 if (chan->channel_type == METADATA_CHANNEL)
2413 return 0;
2414
2415 lttng_metadata_begin(session);
2416
2417 ret = lttng_metadata_printf(session,
2418 "event {\n"
2419 " name = \"%s\";\n"
2420 " id = %u;\n"
2421 " stream_id = %u;\n",
2422 event->desc->name,
2423 event->id,
2424 event->chan->id);
2425 if (ret)
2426 goto end;
2427
2428 if (event->ctx) {
2429 ret = lttng_metadata_printf(session,
2430 " context := struct {\n");
2431 if (ret)
2432 goto end;
2433 }
2434 ret = _lttng_context_metadata_statedump(session, event->ctx);
2435 if (ret)
2436 goto end;
2437 if (event->ctx) {
2438 ret = lttng_metadata_printf(session,
2439 " };\n");
2440 if (ret)
2441 goto end;
2442 }
2443
2444 ret = lttng_metadata_printf(session,
2445 " fields := struct {\n"
2446 );
2447 if (ret)
2448 goto end;
2449
2450 ret = _lttng_fields_metadata_statedump(session, event);
2451 if (ret)
2452 goto end;
2453
2454 /*
2455 * LTTng space reservation can only reserve multiples of the
2456 * byte size.
2457 */
2458 ret = lttng_metadata_printf(session,
2459 " };\n"
2460 "};\n\n");
2461 if (ret)
2462 goto end;
2463
2464 event->metadata_dumped = 1;
2465 end:
2466 lttng_metadata_end(session);
2467 return ret;
2468
2469 }
2470
2471 /*
2472 * Must be called with sessions_mutex held.
2473 * The entire channel metadata is printed as a single atomic metadata
2474 * transaction.
2475 */
2476 static
2477 int _lttng_channel_metadata_statedump(struct lttng_session *session,
2478 struct lttng_channel *chan)
2479 {
2480 int ret = 0;
2481
2482 if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
2483 return 0;
2484
2485 if (chan->channel_type == METADATA_CHANNEL)
2486 return 0;
2487
2488 lttng_metadata_begin(session);
2489
2490 WARN_ON_ONCE(!chan->header_type);
2491 ret = lttng_metadata_printf(session,
2492 "stream {\n"
2493 " id = %u;\n"
2494 " event.header := %s;\n"
2495 " packet.context := struct packet_context;\n",
2496 chan->id,
2497 chan->header_type == 1 ? "struct event_header_compact" :
2498 "struct event_header_large");
2499 if (ret)
2500 goto end;
2501
2502 if (chan->ctx) {
2503 ret = lttng_metadata_printf(session,
2504 " event.context := struct {\n");
2505 if (ret)
2506 goto end;
2507 }
2508 ret = _lttng_context_metadata_statedump(session, chan->ctx);
2509 if (ret)
2510 goto end;
2511 if (chan->ctx) {
2512 ret = lttng_metadata_printf(session,
2513 " };\n");
2514 if (ret)
2515 goto end;
2516 }
2517
2518 ret = lttng_metadata_printf(session,
2519 "};\n\n");
2520
2521 chan->metadata_dumped = 1;
2522 end:
2523 lttng_metadata_end(session);
2524 return ret;
2525 }
2526
2527 /*
2528 * Must be called with sessions_mutex held.
2529 */
2530 static
2531 int _lttng_stream_packet_context_declare(struct lttng_session *session)
2532 {
2533 return lttng_metadata_printf(session,
2534 "struct packet_context {\n"
2535 " uint64_clock_monotonic_t timestamp_begin;\n"
2536 " uint64_clock_monotonic_t timestamp_end;\n"
2537 " uint64_t content_size;\n"
2538 " uint64_t packet_size;\n"
2539 " uint64_t packet_seq_num;\n"
2540 " unsigned long events_discarded;\n"
2541 " uint32_t cpu_id;\n"
2542 "};\n\n"
2543 );
2544 }
2545
2546 /*
2547 * Compact header:
2548 * id: range: 0 - 30.
2549 * id 31 is reserved to indicate an extended header.
2550 *
2551 * Large header:
2552 * id: range: 0 - 65534.
2553 * id 65535 is reserved to indicate an extended header.
2554 *
2555 * Must be called with sessions_mutex held.
2556 */
2557 static
2558 int _lttng_event_header_declare(struct lttng_session *session)
2559 {
2560 return lttng_metadata_printf(session,
2561 "struct event_header_compact {\n"
2562 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
2563 " variant <id> {\n"
2564 " struct {\n"
2565 " uint27_clock_monotonic_t timestamp;\n"
2566 " } compact;\n"
2567 " struct {\n"
2568 " uint32_t id;\n"
2569 " uint64_clock_monotonic_t timestamp;\n"
2570 " } extended;\n"
2571 " } v;\n"
2572 "} align(%u);\n"
2573 "\n"
2574 "struct event_header_large {\n"
2575 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
2576 " variant <id> {\n"
2577 " struct {\n"
2578 " uint32_clock_monotonic_t timestamp;\n"
2579 " } compact;\n"
2580 " struct {\n"
2581 " uint32_t id;\n"
2582 " uint64_clock_monotonic_t timestamp;\n"
2583 " } extended;\n"
2584 " } v;\n"
2585 "} align(%u);\n\n",
2586 lttng_alignof(uint32_t) * CHAR_BIT,
2587 lttng_alignof(uint16_t) * CHAR_BIT
2588 );
2589 }
2590
2591 /*
2592 * Approximation of NTP time of day to clock monotonic correlation,
2593 * taken at start of trace.
2594 * Yes, this is only an approximation. Yes, we can (and will) do better
2595 * in future versions.
2596 * This function may return a negative offset. It may happen if the
2597 * system sets the REALTIME clock to 0 after boot.
2598 *
2599 * Use 64bit timespec on kernels that have it, this makes 32bit arch
2600 * y2038 compliant.
2601 */
2602 static
2603 int64_t measure_clock_offset(void)
2604 {
2605 uint64_t monotonic_avg, monotonic[2], realtime;
2606 uint64_t tcf = trace_clock_freq();
2607 int64_t offset;
2608 unsigned long flags;
2609 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
2610 struct timespec64 rts = { 0, 0 };
2611 #else
2612 struct timespec rts = { 0, 0 };
2613 #endif
2614
2615 /* Disable interrupts to increase correlation precision. */
2616 local_irq_save(flags);
2617 monotonic[0] = trace_clock_read64();
2618 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
2619 ktime_get_real_ts64(&rts);
2620 #else
2621 getnstimeofday(&rts);
2622 #endif
2623 monotonic[1] = trace_clock_read64();
2624 local_irq_restore(flags);
2625
2626 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
2627 realtime = (uint64_t) rts.tv_sec * tcf;
2628 if (tcf == NSEC_PER_SEC) {
2629 realtime += rts.tv_nsec;
2630 } else {
2631 uint64_t n = rts.tv_nsec * tcf;
2632
2633 do_div(n, NSEC_PER_SEC);
2634 realtime += n;
2635 }
2636 offset = (int64_t) realtime - monotonic_avg;
2637 return offset;
2638 }
2639
2640 static
2641 int print_escaped_ctf_string(struct lttng_session *session, const char *string)
2642 {
2643 int ret = 0;
2644 size_t i;
2645 char cur;
2646
2647 i = 0;
2648 cur = string[i];
2649 while (cur != '\0') {
2650 switch (cur) {
2651 case '\n':
2652 ret = lttng_metadata_printf(session, "%s", "\\n");
2653 break;
2654 case '\\':
2655 case '"':
2656 ret = lttng_metadata_printf(session, "%c", '\\');
2657 if (ret)
2658 goto error;
2659 /* We still print the current char */
2660 lttng_fallthrough;
2661 default:
2662 ret = lttng_metadata_printf(session, "%c", cur);
2663 break;
2664 }
2665
2666 if (ret)
2667 goto error;
2668
2669 cur = string[++i];
2670 }
2671 error:
2672 return ret;
2673 }
2674
2675 static
2676 int print_metadata_escaped_field(struct lttng_session *session, const char *field,
2677 const char *field_value)
2678 {
2679 int ret;
2680
2681 ret = lttng_metadata_printf(session, " %s = \"", field);
2682 if (ret)
2683 goto error;
2684
2685 ret = print_escaped_ctf_string(session, field_value);
2686 if (ret)
2687 goto error;
2688
2689 ret = lttng_metadata_printf(session, "\";\n");
2690
2691 error:
2692 return ret;
2693 }
2694
2695 /*
2696 * Output metadata into this session's metadata buffers.
2697 * Must be called with sessions_mutex held.
2698 */
2699 static
2700 int _lttng_session_metadata_statedump(struct lttng_session *session)
2701 {
2702 unsigned char *uuid_c = session->uuid.b;
2703 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
2704 const char *product_uuid;
2705 struct lttng_channel *chan;
2706 struct lttng_event *event;
2707 int ret = 0;
2708
2709 if (!LTTNG_READ_ONCE(session->active))
2710 return 0;
2711
2712 lttng_metadata_begin(session);
2713
2714 if (session->metadata_dumped)
2715 goto skip_session;
2716
2717 snprintf(uuid_s, sizeof(uuid_s),
2718 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
2719 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
2720 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
2721 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
2722 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
2723
2724 ret = lttng_metadata_printf(session,
2725 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
2726 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
2727 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
2728 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
2729 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
2730 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
2731 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
2732 "\n"
2733 "trace {\n"
2734 " major = %u;\n"
2735 " minor = %u;\n"
2736 " uuid = \"%s\";\n"
2737 " byte_order = %s;\n"
2738 " packet.header := struct {\n"
2739 " uint32_t magic;\n"
2740 " uint8_t uuid[16];\n"
2741 " uint32_t stream_id;\n"
2742 " uint64_t stream_instance_id;\n"
2743 " };\n"
2744 "};\n\n",
2745 lttng_alignof(uint8_t) * CHAR_BIT,
2746 lttng_alignof(uint16_t) * CHAR_BIT,
2747 lttng_alignof(uint32_t) * CHAR_BIT,
2748 lttng_alignof(uint64_t) * CHAR_BIT,
2749 sizeof(unsigned long) * CHAR_BIT,
2750 lttng_alignof(unsigned long) * CHAR_BIT,
2751 CTF_SPEC_MAJOR,
2752 CTF_SPEC_MINOR,
2753 uuid_s,
2754 #if __BYTE_ORDER == __BIG_ENDIAN
2755 "be"
2756 #else
2757 "le"
2758 #endif
2759 );
2760 if (ret)
2761 goto end;
2762
2763 ret = lttng_metadata_printf(session,
2764 "env {\n"
2765 " hostname = \"%s\";\n"
2766 " domain = \"kernel\";\n"
2767 " sysname = \"%s\";\n"
2768 " kernel_release = \"%s\";\n"
2769 " kernel_version = \"%s\";\n"
2770 " tracer_name = \"lttng-modules\";\n"
2771 " tracer_major = %d;\n"
2772 " tracer_minor = %d;\n"
2773 " tracer_patchlevel = %d;\n"
2774 " trace_buffering_scheme = \"global\";\n",
2775 current->nsproxy->uts_ns->name.nodename,
2776 utsname()->sysname,
2777 utsname()->release,
2778 utsname()->version,
2779 LTTNG_MODULES_MAJOR_VERSION,
2780 LTTNG_MODULES_MINOR_VERSION,
2781 LTTNG_MODULES_PATCHLEVEL_VERSION
2782 );
2783 if (ret)
2784 goto end;
2785
2786 ret = print_metadata_escaped_field(session, "trace_name", session->name);
2787 if (ret)
2788 goto end;
2789 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
2790 session->creation_time);
2791 if (ret)
2792 goto end;
2793
2794 /* Add the product UUID to the 'env' section */
2795 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
2796 if (product_uuid) {
2797 ret = lttng_metadata_printf(session,
2798 " product_uuid = \"%s\";\n",
2799 product_uuid
2800 );
2801 if (ret)
2802 goto end;
2803 }
2804
2805 /* Close the 'env' section */
2806 ret = lttng_metadata_printf(session, "};\n\n");
2807 if (ret)
2808 goto end;
2809
2810 ret = lttng_metadata_printf(session,
2811 "clock {\n"
2812 " name = \"%s\";\n",
2813 trace_clock_name()
2814 );
2815 if (ret)
2816 goto end;
2817
2818 if (!trace_clock_uuid(clock_uuid_s)) {
2819 ret = lttng_metadata_printf(session,
2820 " uuid = \"%s\";\n",
2821 clock_uuid_s
2822 );
2823 if (ret)
2824 goto end;
2825 }
2826
2827 ret = lttng_metadata_printf(session,
2828 " description = \"%s\";\n"
2829 " freq = %llu; /* Frequency, in Hz */\n"
2830 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
2831 " offset = %lld;\n"
2832 "};\n\n",
2833 trace_clock_description(),
2834 (unsigned long long) trace_clock_freq(),
2835 (long long) measure_clock_offset()
2836 );
2837 if (ret)
2838 goto end;
2839
2840 ret = lttng_metadata_printf(session,
2841 "typealias integer {\n"
2842 " size = 27; align = 1; signed = false;\n"
2843 " map = clock.%s.value;\n"
2844 "} := uint27_clock_monotonic_t;\n"
2845 "\n"
2846 "typealias integer {\n"
2847 " size = 32; align = %u; signed = false;\n"
2848 " map = clock.%s.value;\n"
2849 "} := uint32_clock_monotonic_t;\n"
2850 "\n"
2851 "typealias integer {\n"
2852 " size = 64; align = %u; signed = false;\n"
2853 " map = clock.%s.value;\n"
2854 "} := uint64_clock_monotonic_t;\n\n",
2855 trace_clock_name(),
2856 lttng_alignof(uint32_t) * CHAR_BIT,
2857 trace_clock_name(),
2858 lttng_alignof(uint64_t) * CHAR_BIT,
2859 trace_clock_name()
2860 );
2861 if (ret)
2862 goto end;
2863
2864 ret = _lttng_stream_packet_context_declare(session);
2865 if (ret)
2866 goto end;
2867
2868 ret = _lttng_event_header_declare(session);
2869 if (ret)
2870 goto end;
2871
2872 skip_session:
2873 list_for_each_entry(chan, &session->chan, list) {
2874 ret = _lttng_channel_metadata_statedump(session, chan);
2875 if (ret)
2876 goto end;
2877 }
2878
2879 list_for_each_entry(event, &session->events, list) {
2880 ret = _lttng_event_metadata_statedump(session, event->chan, event);
2881 if (ret)
2882 goto end;
2883 }
2884 session->metadata_dumped = 1;
2885 end:
2886 lttng_metadata_end(session);
2887 return ret;
2888 }
2889
2890 /**
2891 * lttng_transport_register - LTT transport registration
2892 * @transport: transport structure
2893 *
2894 * Registers a transport which can be used as output to extract the data out of
2895 * LTTng. The module calling this registration function must ensure that no
2896 * trap-inducing code will be executed by the transport functions. E.g.
2897 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
2898 * is made visible to the transport function. This registration acts as a
2899 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
2900 * after its registration must it synchronize the TLBs.
2901 */
2902 void lttng_transport_register(struct lttng_transport *transport)
2903 {
2904 /*
2905 * Make sure no page fault can be triggered by the module about to be
2906 * registered. We deal with this here so we don't have to call
2907 * vmalloc_sync_mappings() in each module's init.
2908 */
2909 wrapper_vmalloc_sync_mappings();
2910
2911 mutex_lock(&sessions_mutex);
2912 list_add_tail(&transport->node, &lttng_transport_list);
2913 mutex_unlock(&sessions_mutex);
2914 }
2915 EXPORT_SYMBOL_GPL(lttng_transport_register);
2916
2917 /**
2918 * lttng_transport_unregister - LTT transport unregistration
2919 * @transport: transport structure
2920 */
2921 void lttng_transport_unregister(struct lttng_transport *transport)
2922 {
2923 mutex_lock(&sessions_mutex);
2924 list_del(&transport->node);
2925 mutex_unlock(&sessions_mutex);
2926 }
2927 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
2928
2929 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
2930
2931 enum cpuhp_state lttng_hp_prepare;
2932 enum cpuhp_state lttng_hp_online;
2933
2934 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
2935 {
2936 struct lttng_cpuhp_node *lttng_node;
2937
2938 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2939 switch (lttng_node->component) {
2940 case LTTNG_RING_BUFFER_FRONTEND:
2941 return 0;
2942 case LTTNG_RING_BUFFER_BACKEND:
2943 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
2944 case LTTNG_RING_BUFFER_ITER:
2945 return 0;
2946 case LTTNG_CONTEXT_PERF_COUNTERS:
2947 return 0;
2948 default:
2949 return -EINVAL;
2950 }
2951 }
2952
2953 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
2954 {
2955 struct lttng_cpuhp_node *lttng_node;
2956
2957 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2958 switch (lttng_node->component) {
2959 case LTTNG_RING_BUFFER_FRONTEND:
2960 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
2961 case LTTNG_RING_BUFFER_BACKEND:
2962 return 0;
2963 case LTTNG_RING_BUFFER_ITER:
2964 return 0;
2965 case LTTNG_CONTEXT_PERF_COUNTERS:
2966 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
2967 default:
2968 return -EINVAL;
2969 }
2970 }
2971
2972 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
2973 {
2974 struct lttng_cpuhp_node *lttng_node;
2975
2976 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2977 switch (lttng_node->component) {
2978 case LTTNG_RING_BUFFER_FRONTEND:
2979 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
2980 case LTTNG_RING_BUFFER_BACKEND:
2981 return 0;
2982 case LTTNG_RING_BUFFER_ITER:
2983 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
2984 case LTTNG_CONTEXT_PERF_COUNTERS:
2985 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
2986 default:
2987 return -EINVAL;
2988 }
2989 }
2990
2991 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
2992 {
2993 struct lttng_cpuhp_node *lttng_node;
2994
2995 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
2996 switch (lttng_node->component) {
2997 case LTTNG_RING_BUFFER_FRONTEND:
2998 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
2999 case LTTNG_RING_BUFFER_BACKEND:
3000 return 0;
3001 case LTTNG_RING_BUFFER_ITER:
3002 return 0;
3003 case LTTNG_CONTEXT_PERF_COUNTERS:
3004 return 0;
3005 default:
3006 return -EINVAL;
3007 }
3008 }
3009
3010 static int __init lttng_init_cpu_hotplug(void)
3011 {
3012 int ret;
3013
3014 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
3015 lttng_hotplug_prepare,
3016 lttng_hotplug_dead);
3017 if (ret < 0) {
3018 return ret;
3019 }
3020 lttng_hp_prepare = ret;
3021 lttng_rb_set_hp_prepare(ret);
3022
3023 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
3024 lttng_hotplug_online,
3025 lttng_hotplug_offline);
3026 if (ret < 0) {
3027 cpuhp_remove_multi_state(lttng_hp_prepare);
3028 lttng_hp_prepare = 0;
3029 return ret;
3030 }
3031 lttng_hp_online = ret;
3032 lttng_rb_set_hp_online(ret);
3033
3034 return 0;
3035 }
3036
3037 static void __exit lttng_exit_cpu_hotplug(void)
3038 {
3039 lttng_rb_set_hp_online(0);
3040 cpuhp_remove_multi_state(lttng_hp_online);
3041 lttng_rb_set_hp_prepare(0);
3042 cpuhp_remove_multi_state(lttng_hp_prepare);
3043 }
3044
3045 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
3046 static int lttng_init_cpu_hotplug(void)
3047 {
3048 return 0;
3049 }
3050 static void lttng_exit_cpu_hotplug(void)
3051 {
3052 }
3053 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
3054
3055
3056 static int __init lttng_events_init(void)
3057 {
3058 int ret;
3059
3060 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
3061 if (ret)
3062 return ret;
3063 ret = wrapper_get_pfnblock_flags_mask_init();
3064 if (ret)
3065 return ret;
3066 ret = wrapper_get_pageblock_flags_mask_init();
3067 if (ret)
3068 return ret;
3069 ret = lttng_probes_init();
3070 if (ret)
3071 return ret;
3072 ret = lttng_context_init();
3073 if (ret)
3074 return ret;
3075 ret = lttng_tracepoint_init();
3076 if (ret)
3077 goto error_tp;
3078 event_cache = KMEM_CACHE(lttng_event, 0);
3079 if (!event_cache) {
3080 ret = -ENOMEM;
3081 goto error_kmem;
3082 }
3083 ret = lttng_abi_init();
3084 if (ret)
3085 goto error_abi;
3086 ret = lttng_logger_init();
3087 if (ret)
3088 goto error_logger;
3089 ret = lttng_init_cpu_hotplug();
3090 if (ret)
3091 goto error_hotplug;
3092 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
3093 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3094 __stringify(LTTNG_MODULES_MINOR_VERSION),
3095 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3096 LTTNG_MODULES_EXTRAVERSION,
3097 LTTNG_VERSION_NAME,
3098 #ifdef LTTNG_EXTRA_VERSION_GIT
3099 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3100 #else
3101 "",
3102 #endif
3103 #ifdef LTTNG_EXTRA_VERSION_NAME
3104 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3105 #else
3106 "");
3107 #endif
3108 #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
3109 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
3110 #endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
3111 return 0;
3112
3113 error_hotplug:
3114 lttng_logger_exit();
3115 error_logger:
3116 lttng_abi_exit();
3117 error_abi:
3118 kmem_cache_destroy(event_cache);
3119 error_kmem:
3120 lttng_tracepoint_exit();
3121 error_tp:
3122 lttng_context_exit();
3123 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
3124 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3125 __stringify(LTTNG_MODULES_MINOR_VERSION),
3126 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3127 LTTNG_MODULES_EXTRAVERSION,
3128 LTTNG_VERSION_NAME,
3129 #ifdef LTTNG_EXTRA_VERSION_GIT
3130 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3131 #else
3132 "",
3133 #endif
3134 #ifdef LTTNG_EXTRA_VERSION_NAME
3135 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3136 #else
3137 "");
3138 #endif
3139 return ret;
3140 }
3141
3142 module_init(lttng_events_init);
3143
3144 static void __exit lttng_events_exit(void)
3145 {
3146 struct lttng_session *session, *tmpsession;
3147
3148 lttng_exit_cpu_hotplug();
3149 lttng_logger_exit();
3150 lttng_abi_exit();
3151 list_for_each_entry_safe(session, tmpsession, &sessions, list)
3152 lttng_session_destroy(session);
3153 kmem_cache_destroy(event_cache);
3154 lttng_tracepoint_exit();
3155 lttng_context_exit();
3156 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
3157 __stringify(LTTNG_MODULES_MAJOR_VERSION),
3158 __stringify(LTTNG_MODULES_MINOR_VERSION),
3159 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
3160 LTTNG_MODULES_EXTRAVERSION,
3161 LTTNG_VERSION_NAME,
3162 #ifdef LTTNG_EXTRA_VERSION_GIT
3163 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
3164 #else
3165 "",
3166 #endif
3167 #ifdef LTTNG_EXTRA_VERSION_NAME
3168 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
3169 #else
3170 "");
3171 #endif
3172 }
3173
3174 module_exit(lttng_events_exit);
3175
3176 #include "extra_version/patches.i"
3177 #ifdef LTTNG_EXTRA_VERSION_GIT
3178 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
3179 #endif
3180 #ifdef LTTNG_EXTRA_VERSION_NAME
3181 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
3182 #endif
3183 MODULE_LICENSE("GPL and additional rights");
3184 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
3185 MODULE_DESCRIPTION("LTTng tracer");
3186 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
3187 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
3188 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
3189 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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