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