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