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lttng-events: Add missing static
[lttng-modules.git] / src / lttng-events.c
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1/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
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/uaccess.h>
28#include <linux/vmalloc.h>
29#include <linux/dmi.h>
30
31#include <wrapper/compiler_attributes.h>
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/events-internal.h>
41#include <lttng/lttng-bytecode.h>
42#include <lttng/tracer.h>
43#include <lttng/event-notifier-notification.h>
44#include <lttng/abi-old.h>
45#include <lttng/endian.h>
46#include <lttng/string-utils.h>
47#include <lttng/utils.h>
48#include <ringbuffer/backend.h>
49#include <ringbuffer/frontend.h>
50#include <wrapper/time.h>
51
52#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,16,0) \
53 || LTTNG_RHEL_KERNEL_RANGE(5,14,0,162,0,0, 5,15,0,0,0,0))
54#include <linux/stdarg.h>
55#else
56#include <stdarg.h>
57#endif
58
59#define METADATA_CACHE_DEFAULT_SIZE 4096
60
61static LIST_HEAD(sessions);
62static LIST_HEAD(event_notifier_groups);
63static LIST_HEAD(lttng_transport_list);
64static LIST_HEAD(lttng_counter_transport_list);
65/*
66 * Protect the sessions and metadata caches.
67 */
68static DEFINE_MUTEX(sessions_mutex);
69static struct kmem_cache *event_recorder_cache;
70static struct kmem_cache *event_recorder_private_cache;
71static struct kmem_cache *event_notifier_cache;
72static struct kmem_cache *event_notifier_private_cache;
73
74static void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session);
75static void lttng_session_sync_event_enablers(struct lttng_kernel_session *session);
76static void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler);
77static void lttng_event_notifier_enabler_destroy(struct lttng_event_notifier_enabler *event_notifier_enabler);
78static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
79
80static void _lttng_event_destroy(struct lttng_kernel_event_common *event);
81static void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan);
82static void _lttng_event_unregister(struct lttng_kernel_event_recorder *event);
83static void _lttng_event_notifier_unregister(struct lttng_kernel_event_notifier *event_notifier);
84static
85int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
86 struct lttng_kernel_channel_buffer *chan,
87 struct lttng_kernel_event_recorder *event);
88static
89int _lttng_session_metadata_statedump(struct lttng_kernel_session *session);
90static
91void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
92static
93int _lttng_type_statedump(struct lttng_kernel_session *session,
94 const struct lttng_kernel_type_common *type,
95 enum lttng_kernel_string_encoding parent_encoding,
96 size_t nesting);
97static
98int _lttng_field_statedump(struct lttng_kernel_session *session,
99 const struct lttng_kernel_event_field *field,
100 size_t nesting, const char **prev_field_name_p);
101
102void synchronize_trace(void)
103{
104#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0) || \
105 LTTNG_RHEL_KERNEL_RANGE(4,18,0,193,0,0, 4,19,0,0,0,0))
106 synchronize_rcu();
107#else
108 synchronize_sched();
109#endif
110
111#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
112#ifdef CONFIG_PREEMPT_RT_FULL
113 synchronize_rcu();
114#endif
115#else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
116#ifdef CONFIG_PREEMPT_RT
117 synchronize_rcu();
118#endif
119#endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
120}
121
122void lttng_lock_sessions(void)
123{
124 mutex_lock(&sessions_mutex);
125}
126
127void lttng_unlock_sessions(void)
128{
129 mutex_unlock(&sessions_mutex);
130}
131
132static struct lttng_transport *lttng_transport_find(const char *name)
133{
134 struct lttng_transport *transport;
135
136 list_for_each_entry(transport, &lttng_transport_list, node) {
137 if (!strcmp(transport->name, name))
138 return transport;
139 }
140 return NULL;
141}
142
143/*
144 * Called with sessions lock held.
145 */
146int lttng_session_active(void)
147{
148 struct lttng_kernel_session_private *iter;
149
150 list_for_each_entry(iter, &sessions, list) {
151 if (iter->pub->active)
152 return 1;
153 }
154 return 0;
155}
156
157struct lttng_kernel_session *lttng_session_create(void)
158{
159 struct lttng_kernel_session *session;
160 struct lttng_kernel_session_private *session_priv;
161 struct lttng_metadata_cache *metadata_cache;
162 int i;
163
164 mutex_lock(&sessions_mutex);
165 session = lttng_kvzalloc(sizeof(*session), GFP_KERNEL);
166 if (!session)
167 goto err;
168 session_priv = lttng_kvzalloc(sizeof(*session_priv), GFP_KERNEL);
169 if (!session_priv)
170 goto err_free_session;
171 session->priv = session_priv;
172 session_priv->pub = session;
173
174 INIT_LIST_HEAD(&session_priv->chan);
175 INIT_LIST_HEAD(&session_priv->events);
176 lttng_guid_gen(&session_priv->uuid);
177
178 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
179 GFP_KERNEL);
180 if (!metadata_cache)
181 goto err_free_session_private;
182 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
183 if (!metadata_cache->data)
184 goto err_free_cache;
185 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
186 kref_init(&metadata_cache->refcount);
187 mutex_init(&metadata_cache->lock);
188 session_priv->metadata_cache = metadata_cache;
189 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
190 memcpy(&metadata_cache->uuid, &session_priv->uuid,
191 sizeof(metadata_cache->uuid));
192 INIT_LIST_HEAD(&session_priv->enablers_head);
193 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
194 INIT_HLIST_HEAD(&session_priv->events_ht.table[i]);
195 list_add(&session_priv->list, &sessions);
196
197 if (lttng_id_tracker_init(&session->pid_tracker, session, TRACKER_PID))
198 goto tracker_alloc_error;
199 if (lttng_id_tracker_init(&session->vpid_tracker, session, TRACKER_VPID))
200 goto tracker_alloc_error;
201 if (lttng_id_tracker_init(&session->uid_tracker, session, TRACKER_UID))
202 goto tracker_alloc_error;
203 if (lttng_id_tracker_init(&session->vuid_tracker, session, TRACKER_VUID))
204 goto tracker_alloc_error;
205 if (lttng_id_tracker_init(&session->gid_tracker, session, TRACKER_GID))
206 goto tracker_alloc_error;
207 if (lttng_id_tracker_init(&session->vgid_tracker, session, TRACKER_VGID))
208 goto tracker_alloc_error;
209
210 mutex_unlock(&sessions_mutex);
211
212 return session;
213
214tracker_alloc_error:
215 lttng_id_tracker_fini(&session->pid_tracker);
216 lttng_id_tracker_fini(&session->vpid_tracker);
217 lttng_id_tracker_fini(&session->uid_tracker);
218 lttng_id_tracker_fini(&session->vuid_tracker);
219 lttng_id_tracker_fini(&session->gid_tracker);
220 lttng_id_tracker_fini(&session->vgid_tracker);
221err_free_cache:
222 kfree(metadata_cache);
223err_free_session_private:
224 lttng_kvfree(session_priv);
225err_free_session:
226 lttng_kvfree(session);
227err:
228 mutex_unlock(&sessions_mutex);
229 return NULL;
230}
231
232static
233struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
234{
235 struct lttng_counter_transport *transport;
236
237 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
238 if (!strcmp(transport->name, name))
239 return transport;
240 }
241 return NULL;
242}
243
244struct lttng_counter *lttng_kernel_counter_create(
245 const char *counter_transport_name,
246 size_t number_dimensions, const size_t *dimensions_sizes)
247{
248 struct lttng_counter *counter = NULL;
249 struct lttng_counter_transport *counter_transport = NULL;
250
251 counter_transport = lttng_counter_transport_find(counter_transport_name);
252 if (!counter_transport) {
253 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
254 counter_transport_name);
255 goto notransport;
256 }
257 if (!try_module_get(counter_transport->owner)) {
258 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
259 goto notransport;
260 }
261
262 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
263 if (!counter)
264 goto nomem;
265
266 /* Create event notifier error counter. */
267 counter->ops = &counter_transport->ops;
268 counter->transport = counter_transport;
269
270 counter->counter = counter->ops->counter_create(
271 number_dimensions, dimensions_sizes, 0);
272 if (!counter->counter) {
273 goto create_error;
274 }
275
276 return counter;
277
278create_error:
279 lttng_kvfree(counter);
280nomem:
281 if (counter_transport)
282 module_put(counter_transport->owner);
283notransport:
284 return NULL;
285}
286
287struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
288{
289 struct lttng_transport *transport = NULL;
290 struct lttng_event_notifier_group *event_notifier_group;
291 const char *transport_name = "relay-event-notifier";
292 size_t subbuf_size = 4096; //TODO
293 size_t num_subbuf = 16; //TODO
294 unsigned int switch_timer_interval = 0;
295 unsigned int read_timer_interval = 0;
296 int i;
297
298 mutex_lock(&sessions_mutex);
299
300 transport = lttng_transport_find(transport_name);
301 if (!transport) {
302 printk(KERN_WARNING "LTTng: transport %s not found\n",
303 transport_name);
304 goto notransport;
305 }
306 if (!try_module_get(transport->owner)) {
307 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
308 transport_name);
309 goto notransport;
310 }
311
312 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
313 GFP_KERNEL);
314 if (!event_notifier_group)
315 goto nomem;
316
317 /*
318 * Initialize the ring buffer used to store event notifier
319 * notifications.
320 */
321 event_notifier_group->ops = &transport->ops;
322 event_notifier_group->chan = transport->ops.priv->channel_create(
323 transport_name, event_notifier_group, NULL,
324 subbuf_size, num_subbuf, switch_timer_interval,
325 read_timer_interval);
326 if (!event_notifier_group->chan)
327 goto create_error;
328
329 event_notifier_group->transport = transport;
330
331 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
332 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
333 for (i = 0; i < LTTNG_EVENT_NOTIFIER_HT_SIZE; i++)
334 INIT_HLIST_HEAD(&event_notifier_group->event_notifiers_ht.table[i]);
335
336 list_add(&event_notifier_group->node, &event_notifier_groups);
337
338 mutex_unlock(&sessions_mutex);
339
340 return event_notifier_group;
341
342create_error:
343 lttng_kvfree(event_notifier_group);
344nomem:
345 if (transport)
346 module_put(transport->owner);
347notransport:
348 mutex_unlock(&sessions_mutex);
349 return NULL;
350}
351
352void metadata_cache_destroy(struct kref *kref)
353{
354 struct lttng_metadata_cache *cache =
355 container_of(kref, struct lttng_metadata_cache, refcount);
356 vfree(cache->data);
357 kfree(cache);
358}
359
360void lttng_session_destroy(struct lttng_kernel_session *session)
361{
362 struct lttng_kernel_channel_buffer_private *chan_priv, *tmpchan_priv;
363 struct lttng_kernel_event_recorder_private *event_recorder_priv, *tmpevent_recorder_priv;
364 struct lttng_metadata_stream *metadata_stream;
365 struct lttng_event_enabler *event_enabler, *tmp_event_enabler;
366 int ret;
367
368 mutex_lock(&sessions_mutex);
369 WRITE_ONCE(session->active, 0);
370 list_for_each_entry(chan_priv, &session->priv->chan, node) {
371 ret = lttng_syscalls_unregister_channel(chan_priv->pub);
372 WARN_ON(ret);
373 }
374 list_for_each_entry(event_recorder_priv, &session->priv->events, node)
375 _lttng_event_unregister(event_recorder_priv->pub);
376 synchronize_trace(); /* Wait for in-flight events to complete */
377 list_for_each_entry(chan_priv, &session->priv->chan, node) {
378 ret = lttng_syscalls_destroy_event(chan_priv->pub);
379 WARN_ON(ret);
380 }
381 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
382 &session->priv->enablers_head, node)
383 lttng_event_enabler_destroy(event_enabler);
384 list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv, &session->priv->events, node)
385 _lttng_event_destroy(&event_recorder_priv->pub->parent);
386 list_for_each_entry_safe(chan_priv, tmpchan_priv, &session->priv->chan, node) {
387 BUG_ON(chan_priv->channel_type == METADATA_CHANNEL);
388 _lttng_channel_destroy(chan_priv->pub);
389 }
390 mutex_lock(&session->priv->metadata_cache->lock);
391 list_for_each_entry(metadata_stream, &session->priv->metadata_cache->metadata_stream, list)
392 _lttng_metadata_channel_hangup(metadata_stream);
393 mutex_unlock(&session->priv->metadata_cache->lock);
394 lttng_id_tracker_fini(&session->pid_tracker);
395 lttng_id_tracker_fini(&session->vpid_tracker);
396 lttng_id_tracker_fini(&session->uid_tracker);
397 lttng_id_tracker_fini(&session->vuid_tracker);
398 lttng_id_tracker_fini(&session->gid_tracker);
399 lttng_id_tracker_fini(&session->vgid_tracker);
400 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
401 list_del(&session->priv->list);
402 mutex_unlock(&sessions_mutex);
403 lttng_kvfree(session->priv);
404 lttng_kvfree(session);
405}
406
407void lttng_event_notifier_group_destroy(
408 struct lttng_event_notifier_group *event_notifier_group)
409{
410 struct lttng_event_notifier_enabler *event_notifier_enabler, *tmp_event_notifier_enabler;
411 struct lttng_kernel_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
412 int ret;
413
414 if (!event_notifier_group)
415 return;
416
417 mutex_lock(&sessions_mutex);
418
419 ret = lttng_syscalls_unregister_event_notifier_group(event_notifier_group);
420 WARN_ON(ret);
421
422 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
423 &event_notifier_group->event_notifiers_head, node)
424 _lttng_event_notifier_unregister(event_notifier_priv->pub);
425
426 /* Wait for in-flight event notifier to complete */
427 synchronize_trace();
428
429 irq_work_sync(&event_notifier_group->wakeup_pending);
430
431 kfree(event_notifier_group->sc_filter);
432
433 list_for_each_entry_safe(event_notifier_enabler, tmp_event_notifier_enabler,
434 &event_notifier_group->enablers_head, node)
435 lttng_event_notifier_enabler_destroy(event_notifier_enabler);
436
437 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
438 &event_notifier_group->event_notifiers_head, node)
439 _lttng_event_destroy(&event_notifier_priv->pub->parent);
440
441 if (event_notifier_group->error_counter) {
442 struct lttng_counter *error_counter = event_notifier_group->error_counter;
443
444 error_counter->ops->counter_destroy(error_counter->counter);
445 module_put(error_counter->transport->owner);
446 lttng_kvfree(error_counter);
447 event_notifier_group->error_counter = NULL;
448 }
449
450 event_notifier_group->ops->priv->channel_destroy(event_notifier_group->chan);
451 module_put(event_notifier_group->transport->owner);
452 list_del(&event_notifier_group->node);
453
454 mutex_unlock(&sessions_mutex);
455 lttng_kvfree(event_notifier_group);
456}
457
458int lttng_session_statedump(struct lttng_kernel_session *session)
459{
460 int ret;
461
462 mutex_lock(&sessions_mutex);
463 ret = lttng_statedump_start(session);
464 mutex_unlock(&sessions_mutex);
465 return ret;
466}
467
468int lttng_session_enable(struct lttng_kernel_session *session)
469{
470 int ret = 0;
471 struct lttng_kernel_channel_buffer_private *chan_priv;
472
473 mutex_lock(&sessions_mutex);
474 if (session->active) {
475 ret = -EBUSY;
476 goto end;
477 }
478
479 /* Set transient enabler state to "enabled" */
480 session->priv->tstate = 1;
481
482 /* We need to sync enablers with session before activation. */
483 lttng_session_sync_event_enablers(session);
484
485 /*
486 * Snapshot the number of events per channel to know the type of header
487 * we need to use.
488 */
489 list_for_each_entry(chan_priv, &session->priv->chan, node) {
490 if (chan_priv->header_type)
491 continue; /* don't change it if session stop/restart */
492 if (chan_priv->free_event_id < 31)
493 chan_priv->header_type = 1; /* compact */
494 else
495 chan_priv->header_type = 2; /* large */
496 }
497
498 /* Clear each stream's quiescent state. */
499 list_for_each_entry(chan_priv, &session->priv->chan, node) {
500 if (chan_priv->channel_type != METADATA_CHANNEL)
501 lib_ring_buffer_clear_quiescent_channel(chan_priv->rb_chan);
502 }
503
504 WRITE_ONCE(session->active, 1);
505 WRITE_ONCE(session->priv->been_active, 1);
506 ret = _lttng_session_metadata_statedump(session);
507 if (ret) {
508 WRITE_ONCE(session->active, 0);
509 goto end;
510 }
511 ret = lttng_statedump_start(session);
512 if (ret)
513 WRITE_ONCE(session->active, 0);
514end:
515 mutex_unlock(&sessions_mutex);
516 return ret;
517}
518
519int lttng_session_disable(struct lttng_kernel_session *session)
520{
521 int ret = 0;
522 struct lttng_kernel_channel_buffer_private *chan_priv;
523
524 mutex_lock(&sessions_mutex);
525 if (!session->active) {
526 ret = -EBUSY;
527 goto end;
528 }
529 WRITE_ONCE(session->active, 0);
530
531 /* Set transient enabler state to "disabled" */
532 session->priv->tstate = 0;
533 lttng_session_sync_event_enablers(session);
534
535 /* Set each stream's quiescent state. */
536 list_for_each_entry(chan_priv, &session->priv->chan, node) {
537 if (chan_priv->channel_type != METADATA_CHANNEL)
538 lib_ring_buffer_set_quiescent_channel(chan_priv->rb_chan);
539 }
540end:
541 mutex_unlock(&sessions_mutex);
542 return ret;
543}
544
545int lttng_session_metadata_regenerate(struct lttng_kernel_session *session)
546{
547 int ret = 0;
548 struct lttng_kernel_channel_buffer_private *chan_priv;
549 struct lttng_kernel_event_recorder_private *event_recorder_priv;
550 struct lttng_metadata_cache *cache = session->priv->metadata_cache;
551 struct lttng_metadata_stream *stream;
552
553 mutex_lock(&sessions_mutex);
554 if (!session->active) {
555 ret = -EBUSY;
556 goto end;
557 }
558
559 mutex_lock(&cache->lock);
560 memset(cache->data, 0, cache->cache_alloc);
561 cache->metadata_written = 0;
562 cache->version++;
563 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list) {
564 stream->metadata_out = 0;
565 stream->metadata_in = 0;
566 }
567 mutex_unlock(&cache->lock);
568
569 session->priv->metadata_dumped = 0;
570 list_for_each_entry(chan_priv, &session->priv->chan, node) {
571 chan_priv->metadata_dumped = 0;
572 }
573
574 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
575 event_recorder_priv->metadata_dumped = 0;
576 }
577
578 ret = _lttng_session_metadata_statedump(session);
579
580end:
581 mutex_unlock(&sessions_mutex);
582 return ret;
583}
584
585int lttng_channel_enable(struct lttng_kernel_channel_buffer *channel)
586{
587 int ret = 0;
588
589 mutex_lock(&sessions_mutex);
590 if (channel->priv->channel_type == METADATA_CHANNEL) {
591 ret = -EPERM;
592 goto end;
593 }
594 if (channel->parent.enabled) {
595 ret = -EEXIST;
596 goto end;
597 }
598 /* Set transient enabler state to "enabled" */
599 channel->priv->parent.tstate = 1;
600 lttng_session_sync_event_enablers(channel->parent.session);
601 /* Set atomically the state to "enabled" */
602 WRITE_ONCE(channel->parent.enabled, 1);
603end:
604 mutex_unlock(&sessions_mutex);
605 return ret;
606}
607
608int lttng_channel_disable(struct lttng_kernel_channel_buffer *channel)
609{
610 int ret = 0;
611
612 mutex_lock(&sessions_mutex);
613 if (channel->priv->channel_type == METADATA_CHANNEL) {
614 ret = -EPERM;
615 goto end;
616 }
617 if (!channel->parent.enabled) {
618 ret = -EEXIST;
619 goto end;
620 }
621 /* Set atomically the state to "disabled" */
622 WRITE_ONCE(channel->parent.enabled, 0);
623 /* Set transient enabler state to "enabled" */
624 channel->priv->parent.tstate = 0;
625 lttng_session_sync_event_enablers(channel->parent.session);
626end:
627 mutex_unlock(&sessions_mutex);
628 return ret;
629}
630
631int lttng_event_enable(struct lttng_kernel_event_common *event)
632{
633 int ret = 0;
634
635 mutex_lock(&sessions_mutex);
636 switch (event->type) {
637 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
638 {
639 struct lttng_kernel_event_recorder *event_recorder =
640 container_of(event, struct lttng_kernel_event_recorder, parent);
641
642 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
643 ret = -EPERM;
644 goto end;
645 }
646 break;
647 }
648 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
649 switch (event->priv->instrumentation) {
650 case LTTNG_KERNEL_ABI_KRETPROBE:
651 ret = -EINVAL;
652 goto end;
653 default:
654 break;
655 }
656 break;
657 default:
658 break;
659 }
660
661 if (event->enabled) {
662 ret = -EEXIST;
663 goto end;
664 }
665 switch (event->priv->instrumentation) {
666 case LTTNG_KERNEL_ABI_TRACEPOINT:
667 lttng_fallthrough;
668 case LTTNG_KERNEL_ABI_SYSCALL:
669 ret = -EINVAL;
670 break;
671
672 case LTTNG_KERNEL_ABI_KPROBE:
673 lttng_fallthrough;
674 case LTTNG_KERNEL_ABI_UPROBE:
675 WRITE_ONCE(event->enabled, 1);
676 break;
677
678 case LTTNG_KERNEL_ABI_KRETPROBE:
679 ret = lttng_kretprobes_event_enable_state(event, 1);
680 break;
681
682 case LTTNG_KERNEL_ABI_FUNCTION:
683 lttng_fallthrough;
684 case LTTNG_KERNEL_ABI_NOOP:
685 lttng_fallthrough;
686 default:
687 WARN_ON_ONCE(1);
688 ret = -EINVAL;
689 }
690end:
691 mutex_unlock(&sessions_mutex);
692 return ret;
693}
694
695int lttng_event_disable(struct lttng_kernel_event_common *event)
696{
697 int ret = 0;
698
699 mutex_lock(&sessions_mutex);
700 switch (event->type) {
701 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
702 {
703 struct lttng_kernel_event_recorder *event_recorder =
704 container_of(event, struct lttng_kernel_event_recorder, parent);
705
706 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
707 ret = -EPERM;
708 goto end;
709 }
710 break;
711 }
712 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
713 switch (event->priv->instrumentation) {
714 case LTTNG_KERNEL_ABI_KRETPROBE:
715 ret = -EINVAL;
716 goto end;
717 default:
718 break;
719 }
720 break;
721 default:
722 break;
723 }
724
725 if (!event->enabled) {
726 ret = -EEXIST;
727 goto end;
728 }
729 switch (event->priv->instrumentation) {
730 case LTTNG_KERNEL_ABI_TRACEPOINT:
731 lttng_fallthrough;
732 case LTTNG_KERNEL_ABI_SYSCALL:
733 ret = -EINVAL;
734 break;
735
736 case LTTNG_KERNEL_ABI_KPROBE:
737 lttng_fallthrough;
738 case LTTNG_KERNEL_ABI_UPROBE:
739 WRITE_ONCE(event->enabled, 0);
740 break;
741
742 case LTTNG_KERNEL_ABI_KRETPROBE:
743 ret = lttng_kretprobes_event_enable_state(event, 0);
744 break;
745
746 case LTTNG_KERNEL_ABI_FUNCTION:
747 lttng_fallthrough;
748 case LTTNG_KERNEL_ABI_NOOP:
749 lttng_fallthrough;
750 default:
751 WARN_ON_ONCE(1);
752 ret = -EINVAL;
753 }
754end:
755 mutex_unlock(&sessions_mutex);
756 return ret;
757}
758
759struct lttng_kernel_channel_buffer *lttng_channel_create(struct lttng_kernel_session *session,
760 const char *transport_name,
761 void *buf_addr,
762 size_t subbuf_size, size_t num_subbuf,
763 unsigned int switch_timer_interval,
764 unsigned int read_timer_interval,
765 enum channel_type channel_type)
766{
767 struct lttng_kernel_channel_buffer *chan;
768 struct lttng_kernel_channel_buffer_private *chan_priv;
769 struct lttng_transport *transport = NULL;
770
771 mutex_lock(&sessions_mutex);
772 if (session->priv->been_active && channel_type != METADATA_CHANNEL)
773 goto active; /* Refuse to add channel to active session */
774 transport = lttng_transport_find(transport_name);
775 if (!transport) {
776 printk(KERN_WARNING "LTTng: transport %s not found\n",
777 transport_name);
778 goto notransport;
779 }
780 if (!try_module_get(transport->owner)) {
781 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
782 goto notransport;
783 }
784 chan = kzalloc(sizeof(struct lttng_kernel_channel_buffer), GFP_KERNEL);
785 if (!chan)
786 goto nomem;
787 chan_priv = kzalloc(sizeof(struct lttng_kernel_channel_buffer_private), GFP_KERNEL);
788 if (!chan_priv)
789 goto nomem_priv;
790 chan->priv = chan_priv;
791 chan_priv->pub = chan;
792 chan->parent.type = LTTNG_KERNEL_CHANNEL_TYPE_BUFFER;
793 chan->parent.session = session;
794 chan->priv->id = session->priv->free_chan_id++;
795 chan->ops = &transport->ops;
796 /*
797 * Note: the channel creation op already writes into the packet
798 * headers. Therefore the "chan" information used as input
799 * should be already accessible.
800 */
801 chan->priv->rb_chan = transport->ops.priv->channel_create(transport_name,
802 chan, buf_addr, subbuf_size, num_subbuf,
803 switch_timer_interval, read_timer_interval);
804 if (!chan->priv->rb_chan)
805 goto create_error;
806 chan->priv->parent.tstate = 1;
807 chan->parent.enabled = 1;
808 chan->priv->transport = transport;
809 chan->priv->channel_type = channel_type;
810 list_add(&chan->priv->node, &session->priv->chan);
811 mutex_unlock(&sessions_mutex);
812 return chan;
813
814create_error:
815 kfree(chan_priv);
816nomem_priv:
817 kfree(chan);
818nomem:
819 if (transport)
820 module_put(transport->owner);
821notransport:
822active:
823 mutex_unlock(&sessions_mutex);
824 return NULL;
825}
826
827/*
828 * Only used internally at session destruction for per-cpu channels, and
829 * when metadata channel is released.
830 * Needs to be called with sessions mutex held.
831 */
832static
833void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan)
834{
835 chan->ops->priv->channel_destroy(chan->priv->rb_chan);
836 module_put(chan->priv->transport->owner);
837 list_del(&chan->priv->node);
838 lttng_kernel_destroy_context(chan->priv->ctx);
839 kfree(chan->priv);
840 kfree(chan);
841}
842
843void lttng_metadata_channel_destroy(struct lttng_kernel_channel_buffer *chan)
844{
845 BUG_ON(chan->priv->channel_type != METADATA_CHANNEL);
846
847 /* Protect the metadata cache with the sessions_mutex. */
848 mutex_lock(&sessions_mutex);
849 _lttng_channel_destroy(chan);
850 mutex_unlock(&sessions_mutex);
851}
852EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
853
854static
855void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
856{
857 stream->finalized = 1;
858 wake_up_interruptible(&stream->read_wait);
859}
860
861
862/*
863 * Supports event creation while tracing session is active.
864 * Needs to be called with sessions mutex held.
865 */
866struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
867 struct lttng_kernel_abi_event *event_param,
868 const struct lttng_kernel_event_desc *event_desc,
869 enum lttng_kernel_abi_instrumentation itype)
870{
871 struct lttng_kernel_session *session = chan->parent.session;
872 struct lttng_kernel_event_recorder *event_recorder;
873 struct lttng_kernel_event_recorder_private *event_recorder_priv;
874 const char *event_name;
875 struct hlist_head *head;
876 int ret;
877
878 if (chan->priv->free_event_id == -1U) {
879 ret = -EMFILE;
880 goto full;
881 }
882
883 switch (itype) {
884 case LTTNG_KERNEL_ABI_TRACEPOINT:
885 event_name = event_desc->event_name;
886 break;
887
888 case LTTNG_KERNEL_ABI_KPROBE:
889 lttng_fallthrough;
890 case LTTNG_KERNEL_ABI_UPROBE:
891 lttng_fallthrough;
892 case LTTNG_KERNEL_ABI_KRETPROBE:
893 lttng_fallthrough;
894 case LTTNG_KERNEL_ABI_SYSCALL:
895 event_name = event_param->name;
896 break;
897
898 case LTTNG_KERNEL_ABI_FUNCTION:
899 lttng_fallthrough;
900 case LTTNG_KERNEL_ABI_NOOP:
901 lttng_fallthrough;
902 default:
903 WARN_ON_ONCE(1);
904 ret = -EINVAL;
905 goto type_error;
906 }
907
908 head = utils_borrow_hash_table_bucket(session->priv->events_ht.table,
909 LTTNG_EVENT_HT_SIZE, event_name);
910 lttng_hlist_for_each_entry(event_recorder_priv, head, hlist) {
911 WARN_ON_ONCE(!event_recorder_priv->parent.desc);
912 if (!strncmp(event_recorder_priv->parent.desc->event_name, event_name,
913 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
914 && chan == event_recorder_priv->pub->chan) {
915 ret = -EEXIST;
916 goto exist;
917 }
918 }
919
920 event_recorder = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
921 if (!event_recorder) {
922 ret = -ENOMEM;
923 goto cache_error;
924 }
925 event_recorder_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
926 if (!event_recorder_priv) {
927 ret = -ENOMEM;
928 goto cache_private_error;
929 }
930 event_recorder_priv->pub = event_recorder;
931 event_recorder_priv->parent.pub = &event_recorder->parent;
932 event_recorder->priv = event_recorder_priv;
933 event_recorder->parent.priv = &event_recorder_priv->parent;
934 event_recorder->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
935
936 event_recorder->parent.run_filter = lttng_kernel_interpret_event_filter;
937 event_recorder->chan = chan;
938 event_recorder->priv->id = chan->priv->free_event_id++;
939 event_recorder->priv->parent.instrumentation = itype;
940 INIT_LIST_HEAD(&event_recorder->priv->parent.filter_bytecode_runtime_head);
941 INIT_LIST_HEAD(&event_recorder->priv->parent.enablers_ref_head);
942
943 switch (itype) {
944 case LTTNG_KERNEL_ABI_TRACEPOINT:
945 /* Event will be enabled by enabler sync. */
946 event_recorder->parent.enabled = 0;
947 event_recorder->priv->parent.registered = 0;
948 event_recorder->priv->parent.desc = lttng_event_desc_get(event_name);
949 if (!event_recorder->priv->parent.desc) {
950 ret = -ENOENT;
951 goto register_error;
952 }
953 /* Populate lttng_event structure before event registration. */
954 smp_wmb();
955 break;
956
957 case LTTNG_KERNEL_ABI_KPROBE:
958 /*
959 * Needs to be explicitly enabled after creation, since
960 * we may want to apply filters.
961 */
962 event_recorder->parent.enabled = 0;
963 event_recorder->priv->parent.registered = 1;
964 /*
965 * Populate lttng_event structure before event
966 * registration.
967 */
968 smp_wmb();
969 ret = lttng_kprobes_register_event(event_name,
970 event_param->u.kprobe.symbol_name,
971 event_param->u.kprobe.offset,
972 event_param->u.kprobe.addr,
973 event_recorder);
974 if (ret) {
975 ret = -EINVAL;
976 goto register_error;
977 }
978 ret = try_module_get(event_recorder->priv->parent.desc->owner);
979 WARN_ON_ONCE(!ret);
980 break;
981
982 case LTTNG_KERNEL_ABI_KRETPROBE:
983 {
984 struct lttng_kernel_event_recorder *event_recorder_return;
985 struct lttng_kernel_event_recorder_private *event_recorder_return_priv;
986
987 /* kretprobe defines 2 events */
988 /*
989 * Needs to be explicitly enabled after creation, since
990 * we may want to apply filters.
991 */
992 event_recorder->parent.enabled = 0;
993 event_recorder->priv->parent.registered = 1;
994
995 event_recorder_return = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
996 if (!event_recorder_return) {
997 ret = -ENOMEM;
998 goto register_error;
999 }
1000 event_recorder_return_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
1001 if (!event_recorder_return_priv) {
1002 kmem_cache_free(event_recorder_cache, event_recorder_return);
1003 ret = -ENOMEM;
1004 goto register_error;
1005 }
1006 event_recorder_return_priv->pub = event_recorder_return;
1007 event_recorder_return_priv->parent.pub = &event_recorder_return->parent;
1008 event_recorder_return->priv = event_recorder_return_priv;
1009 event_recorder_return->parent.priv = &event_recorder_return_priv->parent;
1010 event_recorder_return->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
1011
1012 event_recorder_return->parent.run_filter = lttng_kernel_interpret_event_filter;
1013 event_recorder_return->chan = chan;
1014 event_recorder_return->priv->id = chan->priv->free_event_id++;
1015 event_recorder_return->priv->parent.instrumentation = itype;
1016 event_recorder_return->parent.enabled = 0;
1017 event_recorder_return->priv->parent.registered = 1;
1018 INIT_LIST_HEAD(&event_recorder_return->priv->parent.filter_bytecode_runtime_head);
1019 INIT_LIST_HEAD(&event_recorder_return->priv->parent.enablers_ref_head);
1020 /*
1021 * Populate lttng_event structure before kretprobe registration.
1022 */
1023 smp_wmb();
1024 ret = lttng_kretprobes_register(event_name,
1025 event_param->u.kretprobe.symbol_name,
1026 event_param->u.kretprobe.offset,
1027 event_param->u.kretprobe.addr,
1028 event_recorder, event_recorder_return);
1029 if (ret) {
1030 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
1031 kmem_cache_free(event_recorder_cache, event_recorder_return);
1032 ret = -EINVAL;
1033 goto register_error;
1034 }
1035 /* Take 2 refs on the module: one per event. */
1036 ret = try_module_get(event_recorder->priv->parent.desc->owner);
1037 WARN_ON_ONCE(!ret);
1038 ret = try_module_get(event_recorder_return->priv->parent.desc->owner);
1039 WARN_ON_ONCE(!ret);
1040 ret = _lttng_event_metadata_statedump(chan->parent.session, chan,
1041 event_recorder_return);
1042 WARN_ON_ONCE(ret > 0);
1043 if (ret) {
1044 kmem_cache_free(event_recorder_private_cache, event_recorder_return_priv);
1045 kmem_cache_free(event_recorder_cache, event_recorder_return);
1046 module_put(event_recorder_return->priv->parent.desc->owner);
1047 module_put(event_recorder->priv->parent.desc->owner);
1048 goto statedump_error;
1049 }
1050 list_add(&event_recorder_return->priv->node, &chan->parent.session->priv->events);
1051 break;
1052 }
1053
1054 case LTTNG_KERNEL_ABI_SYSCALL:
1055 /*
1056 * Needs to be explicitly enabled after creation, since
1057 * we may want to apply filters.
1058 */
1059 event_recorder->parent.enabled = 0;
1060 event_recorder->priv->parent.registered = 0;
1061 event_recorder->priv->parent.desc = event_desc;
1062 switch (event_param->u.syscall.entryexit) {
1063 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1064 ret = -EINVAL;
1065 goto register_error;
1066 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1067 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1068 break;
1069 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1070 event_recorder->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1071 break;
1072 }
1073 switch (event_param->u.syscall.abi) {
1074 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1075 ret = -EINVAL;
1076 goto register_error;
1077 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1078 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1079 break;
1080 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1081 event_recorder->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1082 break;
1083 }
1084 if (!event_recorder->priv->parent.desc) {
1085 ret = -EINVAL;
1086 goto register_error;
1087 }
1088 break;
1089
1090 case LTTNG_KERNEL_ABI_UPROBE:
1091 /*
1092 * Needs to be explicitly enabled after creation, since
1093 * we may want to apply filters.
1094 */
1095 event_recorder->parent.enabled = 0;
1096 event_recorder->priv->parent.registered = 1;
1097
1098 /*
1099 * Populate lttng_event structure before event
1100 * registration.
1101 */
1102 smp_wmb();
1103
1104 ret = lttng_uprobes_register_event(event_param->name,
1105 event_param->u.uprobe.fd,
1106 event_recorder);
1107 if (ret)
1108 goto register_error;
1109 ret = try_module_get(event_recorder->priv->parent.desc->owner);
1110 WARN_ON_ONCE(!ret);
1111 break;
1112
1113 case LTTNG_KERNEL_ABI_FUNCTION:
1114 lttng_fallthrough;
1115 case LTTNG_KERNEL_ABI_NOOP:
1116 lttng_fallthrough;
1117 default:
1118 WARN_ON_ONCE(1);
1119 ret = -EINVAL;
1120 goto register_error;
1121 }
1122 ret = _lttng_event_metadata_statedump(chan->parent.session, chan, event_recorder);
1123 WARN_ON_ONCE(ret > 0);
1124 if (ret) {
1125 goto statedump_error;
1126 }
1127 hlist_add_head(&event_recorder->priv->hlist, head);
1128 list_add(&event_recorder->priv->node, &chan->parent.session->priv->events);
1129 return event_recorder;
1130
1131statedump_error:
1132 /* If a statedump error occurs, events will not be readable. */
1133register_error:
1134 kmem_cache_free(event_recorder_private_cache, event_recorder_priv);
1135cache_private_error:
1136 kmem_cache_free(event_recorder_cache, event_recorder);
1137cache_error:
1138exist:
1139type_error:
1140full:
1141 return ERR_PTR(ret);
1142}
1143
1144struct lttng_kernel_event_notifier *_lttng_event_notifier_create(
1145 const struct lttng_kernel_event_desc *event_desc,
1146 uint64_t token, uint64_t error_counter_index,
1147 struct lttng_event_notifier_group *event_notifier_group,
1148 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1149 enum lttng_kernel_abi_instrumentation itype)
1150{
1151 struct lttng_kernel_event_notifier *event_notifier;
1152 struct lttng_kernel_event_notifier_private *event_notifier_priv;
1153 struct lttng_counter *error_counter;
1154 const char *event_name;
1155 struct hlist_head *head;
1156 int ret;
1157
1158 switch (itype) {
1159 case LTTNG_KERNEL_ABI_TRACEPOINT:
1160 event_name = event_desc->event_name;
1161 break;
1162
1163 case LTTNG_KERNEL_ABI_KPROBE:
1164 lttng_fallthrough;
1165 case LTTNG_KERNEL_ABI_UPROBE:
1166 lttng_fallthrough;
1167 case LTTNG_KERNEL_ABI_SYSCALL:
1168 event_name = event_notifier_param->event.name;
1169 break;
1170
1171 case LTTNG_KERNEL_ABI_KRETPROBE:
1172 lttng_fallthrough;
1173 case LTTNG_KERNEL_ABI_FUNCTION:
1174 lttng_fallthrough;
1175 case LTTNG_KERNEL_ABI_NOOP:
1176 lttng_fallthrough;
1177 default:
1178 WARN_ON_ONCE(1);
1179 ret = -EINVAL;
1180 goto type_error;
1181 }
1182
1183 head = utils_borrow_hash_table_bucket(event_notifier_group->event_notifiers_ht.table,
1184 LTTNG_EVENT_NOTIFIER_HT_SIZE, event_name);
1185 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
1186 WARN_ON_ONCE(!event_notifier_priv->parent.desc);
1187 if (!strncmp(event_notifier_priv->parent.desc->event_name, event_name,
1188 LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
1189 && event_notifier_group == event_notifier_priv->group
1190 && token == event_notifier_priv->parent.user_token) {
1191 ret = -EEXIST;
1192 goto exist;
1193 }
1194 }
1195
1196 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
1197 if (!event_notifier) {
1198 ret = -ENOMEM;
1199 goto cache_error;
1200 }
1201 event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
1202 if (!event_notifier_priv) {
1203 ret = -ENOMEM;
1204 goto cache_private_error;
1205 }
1206 event_notifier_priv->pub = event_notifier;
1207 event_notifier_priv->parent.pub = &event_notifier->parent;
1208 event_notifier->priv = event_notifier_priv;
1209 event_notifier->parent.priv = &event_notifier_priv->parent;
1210 event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
1211
1212 event_notifier->priv->group = event_notifier_group;
1213 event_notifier->priv->parent.user_token = token;
1214 event_notifier->priv->error_counter_index = error_counter_index;
1215 event_notifier->priv->num_captures = 0;
1216 event_notifier->priv->parent.instrumentation = itype;
1217 event_notifier->notification_send = lttng_event_notifier_notification_send;
1218 INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
1219 INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
1220 INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
1221 event_notifier->parent.run_filter = lttng_kernel_interpret_event_filter;
1222
1223 switch (itype) {
1224 case LTTNG_KERNEL_ABI_TRACEPOINT:
1225 /* Event will be enabled by enabler sync. */
1226 event_notifier->parent.enabled = 0;
1227 event_notifier->priv->parent.registered = 0;
1228 event_notifier->priv->parent.desc = lttng_event_desc_get(event_name);
1229 if (!event_notifier->priv->parent.desc) {
1230 ret = -ENOENT;
1231 goto register_error;
1232 }
1233 /* Populate lttng_event_notifier structure before event registration. */
1234 smp_wmb();
1235 break;
1236
1237 case LTTNG_KERNEL_ABI_KPROBE:
1238 /*
1239 * Needs to be explicitly enabled after creation, since
1240 * we may want to apply filters.
1241 */
1242 event_notifier->parent.enabled = 0;
1243 event_notifier->priv->parent.registered = 1;
1244 /*
1245 * Populate lttng_event_notifier structure before event
1246 * registration.
1247 */
1248 smp_wmb();
1249 ret = lttng_kprobes_register_event_notifier(
1250 event_notifier_param->event.u.kprobe.symbol_name,
1251 event_notifier_param->event.u.kprobe.offset,
1252 event_notifier_param->event.u.kprobe.addr,
1253 event_notifier);
1254 if (ret) {
1255 ret = -EINVAL;
1256 goto register_error;
1257 }
1258 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1259 WARN_ON_ONCE(!ret);
1260 break;
1261
1262 case LTTNG_KERNEL_ABI_SYSCALL:
1263 /*
1264 * Needs to be explicitly enabled after creation, since
1265 * we may want to apply filters.
1266 */
1267 event_notifier->parent.enabled = 0;
1268 event_notifier->priv->parent.registered = 0;
1269 event_notifier->priv->parent.desc = event_desc;
1270 switch (event_notifier_param->event.u.syscall.entryexit) {
1271 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1272 ret = -EINVAL;
1273 goto register_error;
1274 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1275 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1276 break;
1277 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1278 event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1279 break;
1280 }
1281 switch (event_notifier_param->event.u.syscall.abi) {
1282 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1283 ret = -EINVAL;
1284 goto register_error;
1285 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1286 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1287 break;
1288 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1289 event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1290 break;
1291 }
1292
1293 if (!event_notifier->priv->parent.desc) {
1294 ret = -EINVAL;
1295 goto register_error;
1296 }
1297 break;
1298
1299 case LTTNG_KERNEL_ABI_UPROBE:
1300 /*
1301 * Needs to be explicitly enabled after creation, since
1302 * we may want to apply filters.
1303 */
1304 event_notifier->parent.enabled = 0;
1305 event_notifier->priv->parent.registered = 1;
1306
1307 /*
1308 * Populate lttng_event_notifier structure before
1309 * event_notifier registration.
1310 */
1311 smp_wmb();
1312
1313 ret = lttng_uprobes_register_event_notifier(
1314 event_notifier_param->event.name,
1315 event_notifier_param->event.u.uprobe.fd,
1316 event_notifier);
1317 if (ret)
1318 goto register_error;
1319 ret = try_module_get(event_notifier->priv->parent.desc->owner);
1320 WARN_ON_ONCE(!ret);
1321 break;
1322
1323 case LTTNG_KERNEL_ABI_KRETPROBE:
1324 lttng_fallthrough;
1325 case LTTNG_KERNEL_ABI_FUNCTION:
1326 lttng_fallthrough;
1327 case LTTNG_KERNEL_ABI_NOOP:
1328 lttng_fallthrough;
1329 default:
1330 WARN_ON_ONCE(1);
1331 ret = -EINVAL;
1332 goto register_error;
1333 }
1334
1335 list_add(&event_notifier->priv->node, &event_notifier_group->event_notifiers_head);
1336 hlist_add_head(&event_notifier->priv->hlist, head);
1337
1338 /*
1339 * Clear the error counter bucket. The sessiond keeps track of which
1340 * bucket is currently in use. We trust it. The session lock
1341 * synchronizes against concurrent creation of the error
1342 * counter.
1343 */
1344 error_counter = event_notifier_group->error_counter;
1345 if (error_counter) {
1346 size_t dimension_index[1];
1347
1348 /*
1349 * Check that the index is within the boundary of the counter.
1350 */
1351 if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
1352 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1353 event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
1354 ret = -EINVAL;
1355 goto register_error;
1356 }
1357
1358 dimension_index[0] = event_notifier->priv->error_counter_index;
1359 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1360 if (ret) {
1361 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1362 event_notifier->priv->error_counter_index);
1363 goto register_error;
1364 }
1365 }
1366
1367 return event_notifier;
1368
1369register_error:
1370 kmem_cache_free(event_notifier_private_cache, event_notifier_priv);
1371cache_private_error:
1372 kmem_cache_free(event_notifier_cache, event_notifier);
1373cache_error:
1374exist:
1375type_error:
1376 return ERR_PTR(ret);
1377}
1378
1379int lttng_kernel_counter_read(struct lttng_counter *counter,
1380 const size_t *dim_indexes, int32_t cpu,
1381 int64_t *val, bool *overflow, bool *underflow)
1382{
1383 return counter->ops->counter_read(counter->counter, dim_indexes,
1384 cpu, val, overflow, underflow);
1385}
1386
1387int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1388 const size_t *dim_indexes, int64_t *val,
1389 bool *overflow, bool *underflow)
1390{
1391 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1392 val, overflow, underflow);
1393}
1394
1395int lttng_kernel_counter_clear(struct lttng_counter *counter,
1396 const size_t *dim_indexes)
1397{
1398 return counter->ops->counter_clear(counter->counter, dim_indexes);
1399}
1400
1401struct lttng_kernel_event_recorder *lttng_kernel_event_recorder_create(struct lttng_kernel_channel_buffer *chan,
1402 struct lttng_kernel_abi_event *event_param,
1403 const struct lttng_kernel_event_desc *event_desc,
1404 enum lttng_kernel_abi_instrumentation itype)
1405{
1406 struct lttng_kernel_event_recorder *event;
1407
1408 mutex_lock(&sessions_mutex);
1409 event = _lttng_kernel_event_recorder_create(chan, event_param, event_desc, itype);
1410 mutex_unlock(&sessions_mutex);
1411 return event;
1412}
1413
1414struct lttng_kernel_event_notifier *lttng_event_notifier_create(
1415 const struct lttng_kernel_event_desc *event_desc,
1416 uint64_t id, uint64_t error_counter_index,
1417 struct lttng_event_notifier_group *event_notifier_group,
1418 struct lttng_kernel_abi_event_notifier *event_notifier_param,
1419 enum lttng_kernel_abi_instrumentation itype)
1420{
1421 struct lttng_kernel_event_notifier *event_notifier;
1422
1423 mutex_lock(&sessions_mutex);
1424 event_notifier = _lttng_event_notifier_create(event_desc, id,
1425 error_counter_index, event_notifier_group,
1426 event_notifier_param, itype);
1427 mutex_unlock(&sessions_mutex);
1428 return event_notifier;
1429}
1430
1431/* Only used for tracepoints for now. */
1432static
1433void register_event(struct lttng_kernel_event_recorder *event_recorder)
1434{
1435 const struct lttng_kernel_event_desc *desc;
1436 int ret = -EINVAL;
1437
1438 WARN_ON_ONCE(event_recorder->priv->parent.registered);
1439
1440 desc = event_recorder->priv->parent.desc;
1441 switch (event_recorder->priv->parent.instrumentation) {
1442 case LTTNG_KERNEL_ABI_TRACEPOINT:
1443 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1444 desc->tp_class->probe_callback,
1445 event_recorder);
1446 break;
1447
1448 case LTTNG_KERNEL_ABI_SYSCALL:
1449 ret = lttng_syscall_filter_enable_event(event_recorder->chan, event_recorder);
1450 break;
1451
1452 case LTTNG_KERNEL_ABI_KPROBE:
1453 lttng_fallthrough;
1454 case LTTNG_KERNEL_ABI_UPROBE:
1455 lttng_fallthrough;
1456 case LTTNG_KERNEL_ABI_KRETPROBE:
1457 ret = 0;
1458 break;
1459
1460 case LTTNG_KERNEL_ABI_FUNCTION:
1461 lttng_fallthrough;
1462 case LTTNG_KERNEL_ABI_NOOP:
1463 lttng_fallthrough;
1464 default:
1465 WARN_ON_ONCE(1);
1466 }
1467 if (!ret)
1468 event_recorder->priv->parent.registered = 1;
1469}
1470
1471/*
1472 * Only used internally at session destruction.
1473 */
1474static
1475void unregister_event(struct lttng_kernel_event_recorder *event_recorder)
1476{
1477 struct lttng_kernel_event_common_private *event_priv = &event_recorder->priv->parent;
1478 const struct lttng_kernel_event_desc *desc;
1479 int ret = -EINVAL;
1480
1481 WARN_ON_ONCE(!event_priv->registered);
1482
1483 desc = event_priv->desc;
1484 switch (event_priv->instrumentation) {
1485 case LTTNG_KERNEL_ABI_TRACEPOINT:
1486 ret = lttng_wrapper_tracepoint_probe_unregister(event_priv->desc->event_kname,
1487 event_priv->desc->tp_class->probe_callback,
1488 event_recorder);
1489 break;
1490
1491 case LTTNG_KERNEL_ABI_KPROBE:
1492 lttng_kprobes_unregister_event(event_recorder);
1493 ret = 0;
1494 break;
1495
1496 case LTTNG_KERNEL_ABI_KRETPROBE:
1497 lttng_kretprobes_unregister(event_recorder);
1498 ret = 0;
1499 break;
1500
1501 case LTTNG_KERNEL_ABI_SYSCALL:
1502 ret = lttng_syscall_filter_disable_event(event_recorder->chan, event_recorder);
1503 break;
1504
1505 case LTTNG_KERNEL_ABI_NOOP:
1506 ret = 0;
1507 break;
1508
1509 case LTTNG_KERNEL_ABI_UPROBE:
1510 lttng_uprobes_unregister_event(event_recorder);
1511 ret = 0;
1512 break;
1513
1514 case LTTNG_KERNEL_ABI_FUNCTION:
1515 lttng_fallthrough;
1516 default:
1517 WARN_ON_ONCE(1);
1518 }
1519 WARN_ON_ONCE(ret);
1520 if (!ret)
1521 event_priv->registered = 0;
1522}
1523
1524static
1525void _lttng_event_unregister(struct lttng_kernel_event_recorder *event_recorder)
1526{
1527 if (event_recorder->priv->parent.registered)
1528 unregister_event(event_recorder);
1529}
1530
1531/* Only used for tracepoints for now. */
1532static
1533void register_event_notifier(struct lttng_kernel_event_notifier *event_notifier)
1534{
1535 const struct lttng_kernel_event_desc *desc;
1536 int ret = -EINVAL;
1537
1538 WARN_ON_ONCE(event_notifier->priv->parent.registered);
1539
1540 desc = event_notifier->priv->parent.desc;
1541 switch (event_notifier->priv->parent.instrumentation) {
1542 case LTTNG_KERNEL_ABI_TRACEPOINT:
1543 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1544 desc->tp_class->probe_callback,
1545 event_notifier);
1546 break;
1547
1548 case LTTNG_KERNEL_ABI_SYSCALL:
1549 ret = lttng_syscall_filter_enable_event_notifier(event_notifier);
1550 break;
1551
1552 case LTTNG_KERNEL_ABI_KPROBE:
1553 lttng_fallthrough;
1554 case LTTNG_KERNEL_ABI_UPROBE:
1555 ret = 0;
1556 break;
1557
1558 case LTTNG_KERNEL_ABI_KRETPROBE:
1559 lttng_fallthrough;
1560 case LTTNG_KERNEL_ABI_FUNCTION:
1561 lttng_fallthrough;
1562 case LTTNG_KERNEL_ABI_NOOP:
1563 lttng_fallthrough;
1564 default:
1565 WARN_ON_ONCE(1);
1566 }
1567 if (!ret)
1568 event_notifier->priv->parent.registered = 1;
1569}
1570
1571static
1572int unregister_event_notifier(struct lttng_kernel_event_notifier *event_notifier)
1573{
1574 const struct lttng_kernel_event_desc *desc;
1575 int ret = -EINVAL;
1576
1577 WARN_ON_ONCE(!event_notifier->priv->parent.registered);
1578
1579 desc = event_notifier->priv->parent.desc;
1580 switch (event_notifier->priv->parent.instrumentation) {
1581 case LTTNG_KERNEL_ABI_TRACEPOINT:
1582 ret = lttng_wrapper_tracepoint_probe_unregister(event_notifier->priv->parent.desc->event_kname,
1583 event_notifier->priv->parent.desc->tp_class->probe_callback,
1584 event_notifier);
1585 break;
1586
1587 case LTTNG_KERNEL_ABI_KPROBE:
1588 lttng_kprobes_unregister_event_notifier(event_notifier);
1589 ret = 0;
1590 break;
1591
1592 case LTTNG_KERNEL_ABI_UPROBE:
1593 lttng_uprobes_unregister_event_notifier(event_notifier);
1594 ret = 0;
1595 break;
1596
1597 case LTTNG_KERNEL_ABI_SYSCALL:
1598 ret = lttng_syscall_filter_disable_event_notifier(event_notifier);
1599 break;
1600
1601 case LTTNG_KERNEL_ABI_KRETPROBE:
1602 lttng_fallthrough;
1603 case LTTNG_KERNEL_ABI_FUNCTION:
1604 lttng_fallthrough;
1605 case LTTNG_KERNEL_ABI_NOOP:
1606 lttng_fallthrough;
1607 default:
1608 WARN_ON_ONCE(1);
1609 }
1610 if (!ret)
1611 event_notifier->priv->parent.registered = 0;
1612 return ret;
1613}
1614
1615static
1616void _lttng_event_notifier_unregister(struct lttng_kernel_event_notifier *event_notifier)
1617{
1618 if (event_notifier->priv->parent.registered)
1619 unregister_event_notifier(event_notifier);
1620}
1621
1622/*
1623 * Only used internally at session destruction.
1624 */
1625static
1626void _lttng_event_destroy(struct lttng_kernel_event_common *event)
1627{
1628 struct lttng_kernel_event_common_private *event_priv = event->priv;
1629 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1630
1631 lttng_free_event_filter_runtime(event);
1632 /* Free event enabler refs */
1633 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1634 &event_priv->enablers_ref_head, node)
1635 kfree(enabler_ref);
1636
1637 switch (event->type) {
1638 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1639 {
1640 struct lttng_kernel_event_recorder *event_recorder =
1641 container_of(event, struct lttng_kernel_event_recorder, parent);
1642
1643 switch (event_priv->instrumentation) {
1644 case LTTNG_KERNEL_ABI_TRACEPOINT:
1645 lttng_event_desc_put(event_priv->desc);
1646 break;
1647
1648 case LTTNG_KERNEL_ABI_KPROBE:
1649 module_put(event_priv->desc->owner);
1650 lttng_kprobes_destroy_event_private(event_recorder);
1651 break;
1652
1653 case LTTNG_KERNEL_ABI_KRETPROBE:
1654 module_put(event_priv->desc->owner);
1655 lttng_kretprobes_destroy_private(event_recorder);
1656 break;
1657
1658 case LTTNG_KERNEL_ABI_SYSCALL:
1659 break;
1660
1661 case LTTNG_KERNEL_ABI_UPROBE:
1662 module_put(event_priv->desc->owner);
1663 lttng_uprobes_destroy_event_private(event_recorder);
1664 break;
1665
1666 case LTTNG_KERNEL_ABI_FUNCTION:
1667 lttng_fallthrough;
1668 case LTTNG_KERNEL_ABI_NOOP:
1669 lttng_fallthrough;
1670 default:
1671 WARN_ON_ONCE(1);
1672 }
1673 list_del(&event_recorder->priv->node);
1674 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
1675 kmem_cache_free(event_recorder_cache, event_recorder);
1676 break;
1677 }
1678 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1679 {
1680 struct lttng_kernel_event_notifier *event_notifier =
1681 container_of(event, struct lttng_kernel_event_notifier, parent);
1682
1683 switch (event_notifier->priv->parent.instrumentation) {
1684 case LTTNG_KERNEL_ABI_TRACEPOINT:
1685 lttng_event_desc_put(event_notifier->priv->parent.desc);
1686 break;
1687
1688 case LTTNG_KERNEL_ABI_KPROBE:
1689 module_put(event_notifier->priv->parent.desc->owner);
1690 lttng_kprobes_destroy_event_notifier_private(event_notifier);
1691 break;
1692
1693 case LTTNG_KERNEL_ABI_SYSCALL:
1694 break;
1695
1696 case LTTNG_KERNEL_ABI_UPROBE:
1697 module_put(event_notifier->priv->parent.desc->owner);
1698 lttng_uprobes_destroy_event_notifier_private(event_notifier);
1699 break;
1700
1701 case LTTNG_KERNEL_ABI_KRETPROBE:
1702 lttng_fallthrough;
1703 case LTTNG_KERNEL_ABI_FUNCTION:
1704 lttng_fallthrough;
1705 case LTTNG_KERNEL_ABI_NOOP:
1706 lttng_fallthrough;
1707 default:
1708 WARN_ON_ONCE(1);
1709 }
1710 list_del(&event_notifier->priv->node);
1711 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1712 kmem_cache_free(event_notifier_cache, event_notifier);
1713 break;
1714 }
1715 default:
1716 WARN_ON_ONCE(1);
1717 }
1718}
1719
1720static
1721struct lttng_kernel_id_tracker *get_tracker(struct lttng_kernel_session *session,
1722 enum tracker_type tracker_type)
1723{
1724 switch (tracker_type) {
1725 case TRACKER_PID:
1726 return &session->pid_tracker;
1727 case TRACKER_VPID:
1728 return &session->vpid_tracker;
1729 case TRACKER_UID:
1730 return &session->uid_tracker;
1731 case TRACKER_VUID:
1732 return &session->vuid_tracker;
1733 case TRACKER_GID:
1734 return &session->gid_tracker;
1735 case TRACKER_VGID:
1736 return &session->vgid_tracker;
1737 default:
1738 WARN_ON_ONCE(1);
1739 return NULL;
1740 }
1741}
1742
1743int lttng_session_track_id(struct lttng_kernel_session *session,
1744 enum tracker_type tracker_type, int id)
1745{
1746 struct lttng_kernel_id_tracker *tracker;
1747 int ret;
1748
1749 tracker = get_tracker(session, tracker_type);
1750 if (!tracker)
1751 return -EINVAL;
1752 if (id < -1)
1753 return -EINVAL;
1754 mutex_lock(&sessions_mutex);
1755 if (id == -1) {
1756 /* track all ids: destroy tracker. */
1757 lttng_id_tracker_destroy(tracker, true);
1758 ret = 0;
1759 } else {
1760 ret = lttng_id_tracker_add(tracker, id);
1761 }
1762 mutex_unlock(&sessions_mutex);
1763 return ret;
1764}
1765
1766int lttng_session_untrack_id(struct lttng_kernel_session *session,
1767 enum tracker_type tracker_type, int id)
1768{
1769 struct lttng_kernel_id_tracker *tracker;
1770 int ret;
1771
1772 tracker = get_tracker(session, tracker_type);
1773 if (!tracker)
1774 return -EINVAL;
1775 if (id < -1)
1776 return -EINVAL;
1777 mutex_lock(&sessions_mutex);
1778 if (id == -1) {
1779 /* untrack all ids: replace by empty tracker. */
1780 ret = lttng_id_tracker_empty_set(tracker);
1781 } else {
1782 ret = lttng_id_tracker_del(tracker, id);
1783 }
1784 mutex_unlock(&sessions_mutex);
1785 return ret;
1786}
1787
1788static
1789void *id_list_start(struct seq_file *m, loff_t *pos)
1790{
1791 struct lttng_kernel_id_tracker *id_tracker = m->private;
1792 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1793 struct lttng_id_hash_node *e;
1794 int iter = 0, i;
1795
1796 mutex_lock(&sessions_mutex);
1797 if (id_tracker_p) {
1798 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1799 struct hlist_head *head = &id_tracker_p->id_hash[i];
1800
1801 lttng_hlist_for_each_entry(e, head, hlist) {
1802 if (iter++ >= *pos)
1803 return e;
1804 }
1805 }
1806 } else {
1807 /* ID tracker disabled. */
1808 if (iter >= *pos && iter == 0) {
1809 return id_tracker_p; /* empty tracker */
1810 }
1811 iter++;
1812 }
1813 /* End of list */
1814 return NULL;
1815}
1816
1817/* Called with sessions_mutex held. */
1818static
1819void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1820{
1821 struct lttng_kernel_id_tracker *id_tracker = m->private;
1822 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1823 struct lttng_id_hash_node *e;
1824 int iter = 0, i;
1825
1826 (*ppos)++;
1827 if (id_tracker_p) {
1828 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1829 struct hlist_head *head = &id_tracker_p->id_hash[i];
1830
1831 lttng_hlist_for_each_entry(e, head, hlist) {
1832 if (iter++ >= *ppos)
1833 return e;
1834 }
1835 }
1836 } else {
1837 /* ID tracker disabled. */
1838 if (iter >= *ppos && iter == 0)
1839 return p; /* empty tracker */
1840 iter++;
1841 }
1842
1843 /* End of list */
1844 return NULL;
1845}
1846
1847static
1848void id_list_stop(struct seq_file *m, void *p)
1849{
1850 mutex_unlock(&sessions_mutex);
1851}
1852
1853static
1854int id_list_show(struct seq_file *m, void *p)
1855{
1856 struct lttng_kernel_id_tracker *id_tracker = m->private;
1857 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1858 int id;
1859
1860 if (p == id_tracker_p) {
1861 /* Tracker disabled. */
1862 id = -1;
1863 } else {
1864 const struct lttng_id_hash_node *e = p;
1865
1866 id = lttng_id_tracker_get_node_id(e);
1867 }
1868 switch (id_tracker->priv->tracker_type) {
1869 case TRACKER_PID:
1870 seq_printf(m, "process { pid = %d; };\n", id);
1871 break;
1872 case TRACKER_VPID:
1873 seq_printf(m, "process { vpid = %d; };\n", id);
1874 break;
1875 case TRACKER_UID:
1876 seq_printf(m, "user { uid = %d; };\n", id);
1877 break;
1878 case TRACKER_VUID:
1879 seq_printf(m, "user { vuid = %d; };\n", id);
1880 break;
1881 case TRACKER_GID:
1882 seq_printf(m, "group { gid = %d; };\n", id);
1883 break;
1884 case TRACKER_VGID:
1885 seq_printf(m, "group { vgid = %d; };\n", id);
1886 break;
1887 default:
1888 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1889 }
1890 return 0;
1891}
1892
1893static
1894const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1895 .start = id_list_start,
1896 .next = id_list_next,
1897 .stop = id_list_stop,
1898 .show = id_list_show,
1899};
1900
1901static
1902int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1903{
1904 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1905}
1906
1907static
1908int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1909{
1910 struct seq_file *m = file->private_data;
1911 struct lttng_kernel_id_tracker *id_tracker = m->private;
1912 int ret;
1913
1914 WARN_ON_ONCE(!id_tracker);
1915 ret = seq_release(inode, file);
1916 if (!ret)
1917 fput(id_tracker->priv->session->priv->file);
1918 return ret;
1919}
1920
1921const struct file_operations lttng_tracker_ids_list_fops = {
1922 .owner = THIS_MODULE,
1923 .open = lttng_tracker_ids_list_open,
1924 .read = seq_read,
1925 .llseek = seq_lseek,
1926 .release = lttng_tracker_ids_list_release,
1927};
1928
1929int lttng_session_list_tracker_ids(struct lttng_kernel_session *session,
1930 enum tracker_type tracker_type)
1931{
1932 struct file *tracker_ids_list_file;
1933 struct seq_file *m;
1934 int file_fd, ret;
1935
1936 file_fd = lttng_get_unused_fd();
1937 if (file_fd < 0) {
1938 ret = file_fd;
1939 goto fd_error;
1940 }
1941
1942 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1943 &lttng_tracker_ids_list_fops,
1944 NULL, O_RDWR);
1945 if (IS_ERR(tracker_ids_list_file)) {
1946 ret = PTR_ERR(tracker_ids_list_file);
1947 goto file_error;
1948 }
1949 if (!atomic_long_add_unless(&session->priv->file->f_count, 1, LONG_MAX)) {
1950 ret = -EOVERFLOW;
1951 goto refcount_error;
1952 }
1953 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1954 if (ret < 0)
1955 goto open_error;
1956 m = tracker_ids_list_file->private_data;
1957
1958 m->private = get_tracker(session, tracker_type);
1959 BUG_ON(!m->private);
1960 fd_install(file_fd, tracker_ids_list_file);
1961
1962 return file_fd;
1963
1964open_error:
1965 atomic_long_dec(&session->priv->file->f_count);
1966refcount_error:
1967 fput(tracker_ids_list_file);
1968file_error:
1969 put_unused_fd(file_fd);
1970fd_error:
1971 return ret;
1972}
1973
1974/*
1975 * Enabler management.
1976 */
1977static
1978int lttng_match_enabler_star_glob(const char *desc_name,
1979 const char *pattern)
1980{
1981 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1982 desc_name, LTTNG_SIZE_MAX))
1983 return 0;
1984 return 1;
1985}
1986
1987static
1988int lttng_match_enabler_name(const char *desc_name,
1989 const char *name)
1990{
1991 if (strcmp(desc_name, name))
1992 return 0;
1993 return 1;
1994}
1995
1996int lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
1997 struct lttng_enabler *enabler)
1998{
1999 const char *desc_name, *enabler_name;
2000 bool compat = false, entry = false;
2001
2002 enabler_name = enabler->event_param.name;
2003 switch (enabler->event_param.instrumentation) {
2004 case LTTNG_KERNEL_ABI_TRACEPOINT:
2005 desc_name = desc->event_name;
2006 switch (enabler->format_type) {
2007 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2008 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2009 case LTTNG_ENABLER_FORMAT_NAME:
2010 return lttng_match_enabler_name(desc_name, enabler_name);
2011 default:
2012 return -EINVAL;
2013 }
2014 break;
2015
2016 case LTTNG_KERNEL_ABI_SYSCALL:
2017 desc_name = desc->event_name;
2018 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
2019 desc_name += strlen("compat_");
2020 compat = true;
2021 }
2022 if (!strncmp(desc_name, "syscall_exit_",
2023 strlen("syscall_exit_"))) {
2024 desc_name += strlen("syscall_exit_");
2025 } else if (!strncmp(desc_name, "syscall_entry_",
2026 strlen("syscall_entry_"))) {
2027 desc_name += strlen("syscall_entry_");
2028 entry = true;
2029 } else {
2030 WARN_ON_ONCE(1);
2031 return -EINVAL;
2032 }
2033 switch (enabler->event_param.u.syscall.entryexit) {
2034 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
2035 break;
2036 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
2037 if (!entry)
2038 return 0;
2039 break;
2040 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
2041 if (entry)
2042 return 0;
2043 break;
2044 default:
2045 return -EINVAL;
2046 }
2047 switch (enabler->event_param.u.syscall.abi) {
2048 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
2049 break;
2050 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
2051 if (compat)
2052 return 0;
2053 break;
2054 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
2055 if (!compat)
2056 return 0;
2057 break;
2058 default:
2059 return -EINVAL;
2060 }
2061 switch (enabler->event_param.u.syscall.match) {
2062 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
2063 switch (enabler->format_type) {
2064 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2065 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2066 case LTTNG_ENABLER_FORMAT_NAME:
2067 return lttng_match_enabler_name(desc_name, enabler_name);
2068 default:
2069 return -EINVAL;
2070 }
2071 break;
2072 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
2073 return -EINVAL; /* Not implemented. */
2074 default:
2075 return -EINVAL;
2076 }
2077 break;
2078
2079 default:
2080 WARN_ON_ONCE(1);
2081 return -EINVAL;
2082 }
2083}
2084
2085static
2086int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
2087 struct lttng_kernel_event_recorder *event_recorder)
2088{
2089 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(
2090 event_enabler);
2091
2092 if (base_enabler->event_param.instrumentation != event_recorder->priv->parent.instrumentation)
2093 return 0;
2094 if (lttng_desc_match_enabler(event_recorder->priv->parent.desc, base_enabler)
2095 && event_recorder->chan == event_enabler->chan)
2096 return 1;
2097 else
2098 return 0;
2099}
2100
2101static
2102int lttng_event_notifier_enabler_match_event_notifier(struct lttng_event_notifier_enabler *event_notifier_enabler,
2103 struct lttng_kernel_event_notifier *event_notifier)
2104{
2105 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(
2106 event_notifier_enabler);
2107
2108 if (base_enabler->event_param.instrumentation != event_notifier->priv->parent.instrumentation)
2109 return 0;
2110 if (lttng_desc_match_enabler(event_notifier->priv->parent.desc, base_enabler)
2111 && event_notifier->priv->group == event_notifier_enabler->group
2112 && event_notifier->priv->parent.user_token == event_notifier_enabler->base.user_token)
2113 return 1;
2114 else
2115 return 0;
2116}
2117
2118static
2119struct lttng_enabler_ref *lttng_enabler_ref(
2120 struct list_head *enablers_ref_list,
2121 struct lttng_enabler *enabler)
2122{
2123 struct lttng_enabler_ref *enabler_ref;
2124
2125 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2126 if (enabler_ref->ref == enabler)
2127 return enabler_ref;
2128 }
2129 return NULL;
2130}
2131
2132static
2133void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler *event_enabler)
2134{
2135 struct lttng_kernel_session *session = event_enabler->chan->parent.session;
2136 struct lttng_kernel_probe_desc *probe_desc;
2137 const struct lttng_kernel_event_desc *desc;
2138 int i;
2139 struct list_head *probe_list;
2140
2141 probe_list = lttng_get_probe_list_head();
2142 /*
2143 * For each probe event, if we find that a probe event matches
2144 * our enabler, create an associated lttng_event if not
2145 * already present.
2146 */
2147 list_for_each_entry(probe_desc, probe_list, head) {
2148 for (i = 0; i < probe_desc->nr_events; i++) {
2149 int found = 0;
2150 struct hlist_head *head;
2151 struct lttng_kernel_event_recorder_private *event_recorder_private;
2152 struct lttng_kernel_event_recorder *event_recorder;
2153
2154 desc = probe_desc->event_desc[i];
2155 if (!lttng_desc_match_enabler(desc,
2156 lttng_event_enabler_as_enabler(event_enabler)))
2157 continue;
2158
2159 /*
2160 * Check if already created.
2161 */
2162 head = utils_borrow_hash_table_bucket(
2163 session->priv->events_ht.table, LTTNG_EVENT_HT_SIZE,
2164 desc->event_name);
2165 lttng_hlist_for_each_entry(event_recorder_private, head, hlist) {
2166 if (event_recorder_private->parent.desc == desc
2167 && event_recorder_private->pub->chan == event_enabler->chan)
2168 found = 1;
2169 }
2170 if (found)
2171 continue;
2172
2173 /*
2174 * We need to create an event for this
2175 * event probe.
2176 */
2177 event_recorder = _lttng_kernel_event_recorder_create(event_enabler->chan,
2178 NULL, desc, LTTNG_KERNEL_ABI_TRACEPOINT);
2179 if (!event_recorder) {
2180 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2181 probe_desc->event_desc[i]->event_name);
2182 }
2183 }
2184 }
2185}
2186
2187static
2188void lttng_create_tracepoint_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2189{
2190 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2191 struct lttng_kernel_probe_desc *probe_desc;
2192 const struct lttng_kernel_event_desc *desc;
2193 int i;
2194 struct list_head *probe_list;
2195
2196 probe_list = lttng_get_probe_list_head();
2197 /*
2198 * For each probe event, if we find that a probe event matches
2199 * our enabler, create an associated lttng_event_notifier if not
2200 * already present.
2201 */
2202 list_for_each_entry(probe_desc, probe_list, head) {
2203 for (i = 0; i < probe_desc->nr_events; i++) {
2204 int found = 0;
2205 struct hlist_head *head;
2206 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2207 struct lttng_kernel_event_notifier *event_notifier;
2208
2209 desc = probe_desc->event_desc[i];
2210 if (!lttng_desc_match_enabler(desc,
2211 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
2212 continue;
2213
2214 /*
2215 * Check if already created.
2216 */
2217 head = utils_borrow_hash_table_bucket(
2218 event_notifier_group->event_notifiers_ht.table,
2219 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->event_name);
2220 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
2221 if (event_notifier_priv->parent.desc == desc
2222 && event_notifier_priv->parent.user_token == event_notifier_enabler->base.user_token)
2223 found = 1;
2224 }
2225 if (found)
2226 continue;
2227
2228 /*
2229 * We need to create a event_notifier for this event probe.
2230 */
2231 event_notifier = _lttng_event_notifier_create(desc,
2232 event_notifier_enabler->base.user_token,
2233 event_notifier_enabler->error_counter_index,
2234 event_notifier_group, NULL,
2235 LTTNG_KERNEL_ABI_TRACEPOINT);
2236 if (IS_ERR(event_notifier)) {
2237 printk(KERN_INFO "Unable to create event_notifier %s\n",
2238 probe_desc->event_desc[i]->event_name);
2239 }
2240 }
2241 }
2242}
2243
2244static
2245void lttng_create_syscall_event_if_missing(struct lttng_event_enabler *event_enabler)
2246{
2247 int ret;
2248
2249 ret = lttng_syscalls_register_event(event_enabler);
2250 WARN_ON_ONCE(ret);
2251}
2252
2253static
2254void lttng_create_syscall_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2255{
2256 int ret;
2257
2258 ret = lttng_syscalls_register_event_notifier(event_notifier_enabler);
2259 WARN_ON_ONCE(ret);
2260 ret = lttng_syscalls_create_matching_event_notifiers(event_notifier_enabler);
2261 WARN_ON_ONCE(ret);
2262}
2263
2264/*
2265 * Create struct lttng_kernel_event_recorder if it is missing and present in the list of
2266 * tracepoint probes.
2267 * Should be called with sessions mutex held.
2268 */
2269static
2270void lttng_create_event_if_missing(struct lttng_event_enabler *event_enabler)
2271{
2272 switch (event_enabler->base.event_param.instrumentation) {
2273 case LTTNG_KERNEL_ABI_TRACEPOINT:
2274 lttng_create_tracepoint_event_if_missing(event_enabler);
2275 break;
2276
2277 case LTTNG_KERNEL_ABI_SYSCALL:
2278 lttng_create_syscall_event_if_missing(event_enabler);
2279 break;
2280
2281 default:
2282 WARN_ON_ONCE(1);
2283 break;
2284 }
2285}
2286
2287/*
2288 * Create events associated with an event_enabler (if not already present),
2289 * and add backward reference from the event to the enabler.
2290 * Should be called with sessions mutex held.
2291 */
2292static
2293int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
2294{
2295 struct lttng_kernel_channel_buffer *chan = event_enabler->chan;
2296 struct lttng_kernel_session *session = event_enabler->chan->parent.session;
2297 struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
2298 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2299
2300 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2301 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2302 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2303 !strcmp(base_enabler->event_param.name, "*")) {
2304 int enabled = base_enabler->enabled;
2305 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2306
2307 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2308 WRITE_ONCE(chan->priv->parent.syscall_all_entry, enabled);
2309
2310 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2311 WRITE_ONCE(chan->priv->parent.syscall_all_exit, enabled);
2312 }
2313
2314 /* First ensure that probe events are created for this enabler. */
2315 lttng_create_event_if_missing(event_enabler);
2316
2317 /* For each event matching event_enabler in session event list. */
2318 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
2319 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2320 struct lttng_enabler_ref *enabler_ref;
2321
2322 if (!lttng_event_enabler_match_event(event_enabler, event_recorder))
2323 continue;
2324 enabler_ref = lttng_enabler_ref(&event_recorder_priv->parent.enablers_ref_head,
2325 lttng_event_enabler_as_enabler(event_enabler));
2326 if (!enabler_ref) {
2327 /*
2328 * If no backward ref, create it.
2329 * Add backward ref from event to event_enabler.
2330 */
2331 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2332 if (!enabler_ref)
2333 return -ENOMEM;
2334 enabler_ref->ref = lttng_event_enabler_as_enabler(event_enabler);
2335 list_add(&enabler_ref->node,
2336 &event_recorder_priv->parent.enablers_ref_head);
2337 }
2338
2339 /*
2340 * Link filter bytecodes if not linked yet.
2341 */
2342 lttng_enabler_link_bytecode(event_recorder_priv->parent.desc,
2343 lttng_static_ctx,
2344 &event_recorder_priv->parent.filter_bytecode_runtime_head,
2345 &lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
2346 }
2347 return 0;
2348}
2349
2350/*
2351 * Create struct lttng_kernel_event_notifier if it is missing and present in the list of
2352 * tracepoint probes.
2353 * Should be called with sessions mutex held.
2354 */
2355static
2356void lttng_create_event_notifier_if_missing(struct lttng_event_notifier_enabler *event_notifier_enabler)
2357{
2358 switch (event_notifier_enabler->base.event_param.instrumentation) {
2359 case LTTNG_KERNEL_ABI_TRACEPOINT:
2360 lttng_create_tracepoint_event_notifier_if_missing(event_notifier_enabler);
2361 break;
2362
2363 case LTTNG_KERNEL_ABI_SYSCALL:
2364 lttng_create_syscall_event_notifier_if_missing(event_notifier_enabler);
2365 break;
2366
2367 default:
2368 WARN_ON_ONCE(1);
2369 break;
2370 }
2371}
2372
2373/*
2374 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2375 */
2376static
2377int lttng_event_notifier_enabler_ref_event_notifiers(
2378 struct lttng_event_notifier_enabler *event_notifier_enabler)
2379{
2380 struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
2381 struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2382 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2383
2384 if (base_enabler->event_param.instrumentation == LTTNG_KERNEL_ABI_SYSCALL &&
2385 base_enabler->event_param.u.syscall.abi == LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL &&
2386 base_enabler->event_param.u.syscall.match == LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME &&
2387 !strcmp(base_enabler->event_param.name, "*")) {
2388
2389 int enabled = base_enabler->enabled;
2390 enum lttng_kernel_abi_syscall_entryexit entryexit = base_enabler->event_param.u.syscall.entryexit;
2391
2392 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2393 WRITE_ONCE(event_notifier_group->syscall_all_entry, enabled);
2394
2395 if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
2396 WRITE_ONCE(event_notifier_group->syscall_all_exit, enabled);
2397
2398 }
2399
2400 /* First ensure that probe event_notifiers are created for this enabler. */
2401 lttng_create_event_notifier_if_missing(event_notifier_enabler);
2402
2403 /* Link the created event_notifier with its associated enabler. */
2404 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2405 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2406 struct lttng_enabler_ref *enabler_ref;
2407
2408 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier))
2409 continue;
2410
2411 enabler_ref = lttng_enabler_ref(&event_notifier_priv->parent.enablers_ref_head,
2412 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2413 if (!enabler_ref) {
2414 /*
2415 * If no backward ref, create it.
2416 * Add backward ref from event_notifier to enabler.
2417 */
2418 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2419 if (!enabler_ref)
2420 return -ENOMEM;
2421
2422 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2423 event_notifier_enabler);
2424 list_add(&enabler_ref->node,
2425 &event_notifier_priv->parent.enablers_ref_head);
2426 }
2427
2428 /*
2429 * Link filter bytecodes if not linked yet.
2430 */
2431 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2432 lttng_static_ctx, &event_notifier_priv->parent.filter_bytecode_runtime_head,
2433 &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
2434
2435 /* Link capture bytecodes if not linked yet. */
2436 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2437 lttng_static_ctx, &event_notifier_priv->capture_bytecode_runtime_head,
2438 &event_notifier_enabler->capture_bytecode_head);
2439
2440 event_notifier_priv->num_captures = event_notifier_enabler->num_captures;
2441 }
2442 return 0;
2443}
2444
2445/*
2446 * Called at module load: connect the probe on all enablers matching
2447 * this event.
2448 * Called with sessions lock held.
2449 */
2450int lttng_fix_pending_events(void)
2451{
2452 struct lttng_kernel_session_private *session_priv;
2453
2454 list_for_each_entry(session_priv, &sessions, list)
2455 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2456 return 0;
2457}
2458
2459static bool lttng_event_notifier_group_has_active_event_notifiers(
2460 struct lttng_event_notifier_group *event_notifier_group)
2461{
2462 struct lttng_event_notifier_enabler *event_notifier_enabler;
2463
2464 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2465 node) {
2466 if (event_notifier_enabler->base.enabled)
2467 return true;
2468 }
2469 return false;
2470}
2471
2472bool lttng_event_notifier_active(void)
2473{
2474 struct lttng_event_notifier_group *event_notifier_group;
2475
2476 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2477 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2478 return true;
2479 }
2480 return false;
2481}
2482
2483int lttng_fix_pending_event_notifiers(void)
2484{
2485 struct lttng_event_notifier_group *event_notifier_group;
2486
2487 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2488 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2489 return 0;
2490}
2491
2492struct lttng_event_enabler *lttng_event_enabler_create(
2493 enum lttng_enabler_format_type format_type,
2494 struct lttng_kernel_abi_event *event_param,
2495 struct lttng_kernel_channel_buffer *chan)
2496{
2497 struct lttng_event_enabler *event_enabler;
2498
2499 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2500 if (!event_enabler)
2501 return NULL;
2502 event_enabler->base.format_type = format_type;
2503 INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
2504 memcpy(&event_enabler->base.event_param, event_param,
2505 sizeof(event_enabler->base.event_param));
2506 event_enabler->chan = chan;
2507 /* ctx left NULL */
2508 event_enabler->base.enabled = 0;
2509 mutex_lock(&sessions_mutex);
2510 list_add(&event_enabler->node, &event_enabler->chan->parent.session->priv->enablers_head);
2511 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2512 mutex_unlock(&sessions_mutex);
2513 return event_enabler;
2514}
2515
2516int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
2517{
2518 mutex_lock(&sessions_mutex);
2519 lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
2520 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2521 mutex_unlock(&sessions_mutex);
2522 return 0;
2523}
2524
2525int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
2526{
2527 mutex_lock(&sessions_mutex);
2528 lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
2529 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2530 mutex_unlock(&sessions_mutex);
2531 return 0;
2532}
2533
2534static
2535int lttng_enabler_attach_filter_bytecode(struct lttng_enabler *enabler,
2536 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2537{
2538 struct lttng_kernel_bytecode_node *bytecode_node;
2539 uint32_t bytecode_len;
2540 int ret;
2541
2542 ret = get_user(bytecode_len, &bytecode->len);
2543 if (ret)
2544 return ret;
2545 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2546 GFP_KERNEL);
2547 if (!bytecode_node)
2548 return -ENOMEM;
2549 ret = copy_from_user(&bytecode_node->bc, bytecode,
2550 sizeof(*bytecode) + bytecode_len);
2551 if (ret)
2552 goto error_free;
2553
2554 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2555 bytecode_node->enabler = enabler;
2556 /* Enforce length based on allocated size */
2557 bytecode_node->bc.len = bytecode_len;
2558 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2559
2560 return 0;
2561
2562error_free:
2563 lttng_kvfree(bytecode_node);
2564 return ret;
2565}
2566
2567int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler *event_enabler,
2568 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2569{
2570 int ret;
2571 ret = lttng_enabler_attach_filter_bytecode(
2572 lttng_event_enabler_as_enabler(event_enabler), bytecode);
2573 if (ret)
2574 goto error;
2575
2576 lttng_session_lazy_sync_event_enablers(event_enabler->chan->parent.session);
2577 return 0;
2578
2579error:
2580 return ret;
2581}
2582
2583int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2584 struct lttng_kernel_abi_event_callsite __user *callsite)
2585{
2586
2587 switch (event->priv->instrumentation) {
2588 case LTTNG_KERNEL_ABI_UPROBE:
2589 return lttng_uprobes_event_add_callsite(event, callsite);
2590 default:
2591 return -EINVAL;
2592 }
2593}
2594
2595static
2596void lttng_enabler_destroy(struct lttng_enabler *enabler)
2597{
2598 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2599
2600 /* Destroy filter bytecode */
2601 list_for_each_entry_safe(filter_node, tmp_filter_node,
2602 &enabler->filter_bytecode_head, node) {
2603 lttng_kvfree(filter_node);
2604 }
2605}
2606
2607static
2608void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
2609{
2610 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
2611
2612 list_del(&event_enabler->node);
2613 kfree(event_enabler);
2614}
2615
2616struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2617 struct lttng_event_notifier_group *event_notifier_group,
2618 enum lttng_enabler_format_type format_type,
2619 struct lttng_kernel_abi_event_notifier *event_notifier_param)
2620{
2621 struct lttng_event_notifier_enabler *event_notifier_enabler;
2622
2623 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2624 if (!event_notifier_enabler)
2625 return NULL;
2626
2627 event_notifier_enabler->base.format_type = format_type;
2628 INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
2629 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2630
2631 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2632 event_notifier_enabler->num_captures = 0;
2633
2634 memcpy(&event_notifier_enabler->base.event_param, &event_notifier_param->event,
2635 sizeof(event_notifier_enabler->base.event_param));
2636
2637 event_notifier_enabler->base.enabled = 0;
2638 event_notifier_enabler->base.user_token = event_notifier_param->event.token;
2639 event_notifier_enabler->group = event_notifier_group;
2640
2641 mutex_lock(&sessions_mutex);
2642 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2643 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2644
2645 mutex_unlock(&sessions_mutex);
2646
2647 return event_notifier_enabler;
2648}
2649
2650int lttng_event_notifier_enabler_enable(
2651 struct lttng_event_notifier_enabler *event_notifier_enabler)
2652{
2653 mutex_lock(&sessions_mutex);
2654 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2655 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2656 mutex_unlock(&sessions_mutex);
2657 return 0;
2658}
2659
2660int lttng_event_notifier_enabler_disable(
2661 struct lttng_event_notifier_enabler *event_notifier_enabler)
2662{
2663 mutex_lock(&sessions_mutex);
2664 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2665 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2666 mutex_unlock(&sessions_mutex);
2667 return 0;
2668}
2669
2670int lttng_event_notifier_enabler_attach_filter_bytecode(
2671 struct lttng_event_notifier_enabler *event_notifier_enabler,
2672 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2673{
2674 int ret;
2675
2676 ret = lttng_enabler_attach_filter_bytecode(
2677 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
2678 bytecode);
2679 if (ret)
2680 goto error;
2681
2682 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2683 return 0;
2684
2685error:
2686 return ret;
2687}
2688
2689int lttng_event_notifier_enabler_attach_capture_bytecode(
2690 struct lttng_event_notifier_enabler *event_notifier_enabler,
2691 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2692{
2693 struct lttng_kernel_bytecode_node *bytecode_node;
2694 struct lttng_enabler *enabler =
2695 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2696 uint32_t bytecode_len;
2697 int ret;
2698
2699 ret = get_user(bytecode_len, &bytecode->len);
2700 if (ret)
2701 return ret;
2702
2703 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2704 GFP_KERNEL);
2705 if (!bytecode_node)
2706 return -ENOMEM;
2707
2708 ret = copy_from_user(&bytecode_node->bc, bytecode,
2709 sizeof(*bytecode) + bytecode_len);
2710 if (ret)
2711 goto error_free;
2712
2713 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2714 bytecode_node->enabler = enabler;
2715
2716 /* Enforce length based on allocated size */
2717 bytecode_node->bc.len = bytecode_len;
2718 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2719
2720 event_notifier_enabler->num_captures++;
2721
2722 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2723 goto end;
2724
2725error_free:
2726 lttng_kvfree(bytecode_node);
2727end:
2728 return ret;
2729}
2730
2731static
2732void lttng_event_notifier_enabler_destroy(
2733 struct lttng_event_notifier_enabler *event_notifier_enabler)
2734{
2735 if (!event_notifier_enabler) {
2736 return;
2737 }
2738
2739 list_del(&event_notifier_enabler->node);
2740
2741 lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2742 kfree(event_notifier_enabler);
2743}
2744
2745/*
2746 * lttng_session_sync_event_enablers should be called just before starting a
2747 * session.
2748 * Should be called with sessions mutex held.
2749 */
2750static
2751void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2752{
2753 struct lttng_event_enabler *event_enabler;
2754 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2755
2756 list_for_each_entry(event_enabler, &session->priv->enablers_head, node)
2757 lttng_event_enabler_ref_events(event_enabler);
2758 /*
2759 * For each event, if at least one of its enablers is enabled,
2760 * and its channel and session transient states are enabled, we
2761 * enable the event, else we disable it.
2762 */
2763 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
2764 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2765 struct lttng_enabler_ref *enabler_ref;
2766 struct lttng_kernel_bytecode_runtime *runtime;
2767 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2768 int nr_filters = 0;
2769
2770 switch (event_recorder_priv->parent.instrumentation) {
2771 case LTTNG_KERNEL_ABI_TRACEPOINT:
2772 lttng_fallthrough;
2773 case LTTNG_KERNEL_ABI_SYSCALL:
2774 /* Enable events */
2775 list_for_each_entry(enabler_ref,
2776 &event_recorder_priv->parent.enablers_ref_head, node) {
2777 if (enabler_ref->ref->enabled) {
2778 enabled = 1;
2779 break;
2780 }
2781 }
2782 break;
2783
2784 default:
2785 /* Not handled with lazy sync. */
2786 continue;
2787 }
2788 /*
2789 * Enabled state is based on union of enablers, with
2790 * intesection of session and channel transient enable
2791 * states.
2792 */
2793 enabled = enabled && session->priv->tstate && event_recorder->chan->priv->parent.tstate;
2794
2795 WRITE_ONCE(event_recorder->parent.enabled, enabled);
2796 /*
2797 * Sync tracepoint registration with event enabled
2798 * state.
2799 */
2800 if (enabled) {
2801 if (!event_recorder_priv->parent.registered)
2802 register_event(event_recorder);
2803 } else {
2804 if (event_recorder_priv->parent.registered)
2805 _lttng_event_unregister(event_recorder);
2806 }
2807
2808 /* Check if has enablers without bytecode enabled */
2809 list_for_each_entry(enabler_ref,
2810 &event_recorder_priv->parent.enablers_ref_head, node) {
2811 if (enabler_ref->ref->enabled
2812 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2813 has_enablers_without_filter_bytecode = 1;
2814 break;
2815 }
2816 }
2817 event_recorder_priv->parent.has_enablers_without_filter_bytecode =
2818 has_enablers_without_filter_bytecode;
2819
2820 /* Enable filters */
2821 list_for_each_entry(runtime,
2822 &event_recorder_priv->parent.filter_bytecode_runtime_head, node) {
2823 lttng_bytecode_sync_state(runtime);
2824 nr_filters++;
2825 }
2826 WRITE_ONCE(event_recorder_priv->parent.pub->eval_filter,
2827 !(has_enablers_without_filter_bytecode || !nr_filters));
2828 }
2829}
2830
2831/*
2832 * Apply enablers to session events, adding events to session if need
2833 * be. It is required after each modification applied to an active
2834 * session, and right before session "start".
2835 * "lazy" sync means we only sync if required.
2836 * Should be called with sessions mutex held.
2837 */
2838static
2839void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2840{
2841 /* We can skip if session is not active */
2842 if (!session->active)
2843 return;
2844 lttng_session_sync_event_enablers(session);
2845}
2846
2847static
2848void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2849{
2850 struct lttng_event_notifier_enabler *event_notifier_enabler;
2851 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2852
2853 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2854 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2855
2856 /*
2857 * For each event_notifier, if at least one of its enablers is enabled,
2858 * we enable the event_notifier, else we disable it.
2859 */
2860 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
2861 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2862 struct lttng_enabler_ref *enabler_ref;
2863 struct lttng_kernel_bytecode_runtime *runtime;
2864 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2865 int nr_filters = 0, nr_captures = 0;
2866
2867 switch (event_notifier_priv->parent.instrumentation) {
2868 case LTTNG_KERNEL_ABI_TRACEPOINT:
2869 lttng_fallthrough;
2870 case LTTNG_KERNEL_ABI_SYSCALL:
2871 /* Enable event_notifiers */
2872 list_for_each_entry(enabler_ref,
2873 &event_notifier_priv->parent.enablers_ref_head, node) {
2874 if (enabler_ref->ref->enabled) {
2875 enabled = 1;
2876 break;
2877 }
2878 }
2879 break;
2880
2881 default:
2882 /* Not handled with sync. */
2883 continue;
2884 }
2885
2886 WRITE_ONCE(event_notifier->parent.enabled, enabled);
2887 /*
2888 * Sync tracepoint registration with event_notifier enabled
2889 * state.
2890 */
2891 if (enabled) {
2892 if (!event_notifier_priv->parent.registered)
2893 register_event_notifier(event_notifier);
2894 } else {
2895 if (event_notifier_priv->parent.registered)
2896 unregister_event_notifier(event_notifier);
2897 }
2898
2899 /* Check if has enablers without bytecode enabled */
2900 list_for_each_entry(enabler_ref,
2901 &event_notifier_priv->parent.enablers_ref_head, node) {
2902 if (enabler_ref->ref->enabled
2903 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2904 has_enablers_without_filter_bytecode = 1;
2905 break;
2906 }
2907 }
2908 event_notifier_priv->parent.has_enablers_without_filter_bytecode =
2909 has_enablers_without_filter_bytecode;
2910
2911 /* Enable filters */
2912 list_for_each_entry(runtime,
2913 &event_notifier_priv->parent.filter_bytecode_runtime_head, node) {
2914 lttng_bytecode_sync_state(runtime);
2915 nr_filters++;
2916 }
2917 WRITE_ONCE(event_notifier_priv->parent.pub->eval_filter,
2918 !(has_enablers_without_filter_bytecode || !nr_filters));
2919
2920 /* Enable captures */
2921 list_for_each_entry(runtime,
2922 &event_notifier_priv->capture_bytecode_runtime_head, node) {
2923 lttng_bytecode_sync_state(runtime);
2924 nr_captures++;
2925 }
2926 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2927 }
2928}
2929
2930/*
2931 * Serialize at most one packet worth of metadata into a metadata
2932 * channel.
2933 * We grab the metadata cache mutex to get exclusive access to our metadata
2934 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2935 * allows us to do racy operations such as looking for remaining space left in
2936 * packet and write, since mutual exclusion protects us from concurrent writes.
2937 * Mutual exclusion on the metadata cache allow us to read the cache content
2938 * without racing against reallocation of the cache by updates.
2939 * Returns the number of bytes written in the channel, 0 if no data
2940 * was written and a negative value on error.
2941 */
2942int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2943 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2944{
2945 struct lttng_kernel_ring_buffer_ctx ctx;
2946 int ret = 0;
2947 size_t len, reserve_len;
2948
2949 /*
2950 * Ensure we support mutiple get_next / put sequences followed by
2951 * put_next. The metadata cache lock protects reading the metadata
2952 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2953 * "flush" operations on the buffer invoked by different processes.
2954 * Moreover, since the metadata cache memory can be reallocated, we
2955 * need to have exclusive access against updates even though we only
2956 * read it.
2957 */
2958 mutex_lock(&stream->metadata_cache->lock);
2959 WARN_ON(stream->metadata_in < stream->metadata_out);
2960 if (stream->metadata_in != stream->metadata_out)
2961 goto end;
2962
2963 /* Metadata regenerated, change the version. */
2964 if (stream->metadata_cache->version != stream->version)
2965 stream->version = stream->metadata_cache->version;
2966
2967 len = stream->metadata_cache->metadata_written -
2968 stream->metadata_in;
2969 if (!len)
2970 goto end;
2971 reserve_len = min_t(size_t,
2972 stream->transport->ops.priv->packet_avail_size(chan),
2973 len);
2974 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2975 sizeof(char), NULL);
2976 /*
2977 * If reservation failed, return an error to the caller.
2978 */
2979 ret = stream->transport->ops.event_reserve(&ctx);
2980 if (ret != 0) {
2981 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2982 stream->coherent = false;
2983 goto end;
2984 }
2985 stream->transport->ops.event_write(&ctx,
2986 stream->metadata_cache->data + stream->metadata_in,
2987 reserve_len, 1);
2988 stream->transport->ops.event_commit(&ctx);
2989 stream->metadata_in += reserve_len;
2990 if (reserve_len < len)
2991 stream->coherent = false;
2992 else
2993 stream->coherent = true;
2994 ret = reserve_len;
2995
2996end:
2997 if (coherent)
2998 *coherent = stream->coherent;
2999 mutex_unlock(&stream->metadata_cache->lock);
3000 return ret;
3001}
3002
3003static
3004void lttng_metadata_begin(struct lttng_kernel_session *session)
3005{
3006 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
3007 mutex_lock(&session->priv->metadata_cache->lock);
3008}
3009
3010static
3011void lttng_metadata_end(struct lttng_kernel_session *session)
3012{
3013 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
3014 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
3015 struct lttng_metadata_stream *stream;
3016
3017 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
3018 wake_up_interruptible(&stream->read_wait);
3019 mutex_unlock(&session->priv->metadata_cache->lock);
3020 }
3021}
3022
3023/*
3024 * Write the metadata to the metadata cache.
3025 * Must be called with sessions_mutex held.
3026 * The metadata cache lock protects us from concurrent read access from
3027 * thread outputting metadata content to ring buffer.
3028 * The content of the printf is printed as a single atomic metadata
3029 * transaction.
3030 */
3031static
3032int lttng_metadata_printf(struct lttng_kernel_session *session,
3033 const char *fmt, ...)
3034{
3035 char *str;
3036 size_t len;
3037 va_list ap;
3038
3039 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
3040
3041 va_start(ap, fmt);
3042 str = kvasprintf(GFP_KERNEL, fmt, ap);
3043 va_end(ap);
3044 if (!str)
3045 return -ENOMEM;
3046
3047 len = strlen(str);
3048 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
3049 if (session->priv->metadata_cache->metadata_written + len >
3050 session->priv->metadata_cache->cache_alloc) {
3051 char *tmp_cache_realloc;
3052 unsigned int tmp_cache_alloc_size;
3053
3054 tmp_cache_alloc_size = max_t(unsigned int,
3055 session->priv->metadata_cache->cache_alloc + len,
3056 session->priv->metadata_cache->cache_alloc << 1);
3057 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
3058 if (!tmp_cache_realloc)
3059 goto err;
3060 if (session->priv->metadata_cache->data) {
3061 memcpy(tmp_cache_realloc,
3062 session->priv->metadata_cache->data,
3063 session->priv->metadata_cache->cache_alloc);
3064 vfree(session->priv->metadata_cache->data);
3065 }
3066
3067 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
3068 session->priv->metadata_cache->data = tmp_cache_realloc;
3069 }
3070 memcpy(session->priv->metadata_cache->data +
3071 session->priv->metadata_cache->metadata_written,
3072 str, len);
3073 session->priv->metadata_cache->metadata_written += len;
3074 kfree(str);
3075
3076 return 0;
3077
3078err:
3079 kfree(str);
3080 return -ENOMEM;
3081}
3082
3083static
3084int print_tabs(struct lttng_kernel_session *session, size_t nesting)
3085{
3086 size_t i;
3087
3088 for (i = 0; i < nesting; i++) {
3089 int ret;
3090
3091 ret = lttng_metadata_printf(session, " ");
3092 if (ret) {
3093 return ret;
3094 }
3095 }
3096 return 0;
3097}
3098
3099static
3100int lttng_field_name_statedump(struct lttng_kernel_session *session,
3101 const struct lttng_kernel_event_field *field,
3102 size_t nesting)
3103{
3104 return lttng_metadata_printf(session, " _%s;\n", field->name);
3105}
3106
3107static
3108int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
3109 const struct lttng_kernel_type_integer *type,
3110 enum lttng_kernel_string_encoding parent_encoding,
3111 size_t nesting)
3112{
3113 int ret;
3114
3115 ret = print_tabs(session, nesting);
3116 if (ret)
3117 return ret;
3118 ret = lttng_metadata_printf(session,
3119 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
3120 type->size,
3121 type->alignment,
3122 type->signedness,
3123 (parent_encoding == lttng_kernel_string_encoding_none)
3124 ? "none"
3125 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
3126 ? "UTF8"
3127 : "ASCII",
3128 type->base,
3129#if __BYTE_ORDER == __BIG_ENDIAN
3130 type->reverse_byte_order ? " byte_order = le;" : ""
3131#else
3132 type->reverse_byte_order ? " byte_order = be;" : ""
3133#endif
3134 );
3135 return ret;
3136}
3137
3138/*
3139 * Must be called with sessions_mutex held.
3140 */
3141static
3142int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
3143 const struct lttng_kernel_type_struct *type,
3144 size_t nesting)
3145{
3146 const char *prev_field_name = NULL;
3147 int ret;
3148 uint32_t i, nr_fields;
3149 unsigned int alignment;
3150
3151 ret = print_tabs(session, nesting);
3152 if (ret)
3153 return ret;
3154 ret = lttng_metadata_printf(session,
3155 "struct {\n");
3156 if (ret)
3157 return ret;
3158 nr_fields = type->nr_fields;
3159 for (i = 0; i < nr_fields; i++) {
3160 const struct lttng_kernel_event_field *iter_field;
3161
3162 iter_field = type->fields[i];
3163 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
3164 if (ret)
3165 return ret;
3166 }
3167 ret = print_tabs(session, nesting);
3168 if (ret)
3169 return ret;
3170 alignment = type->alignment;
3171 if (alignment) {
3172 ret = lttng_metadata_printf(session,
3173 "} align(%u)",
3174 alignment);
3175 } else {
3176 ret = lttng_metadata_printf(session,
3177 "}");
3178 }
3179 return ret;
3180}
3181
3182/*
3183 * Must be called with sessions_mutex held.
3184 */
3185static
3186int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
3187 const struct lttng_kernel_event_field *field,
3188 size_t nesting)
3189{
3190 int ret;
3191
3192 ret = _lttng_struct_type_statedump(session,
3193 lttng_kernel_get_type_struct(field->type), nesting);
3194 if (ret)
3195 return ret;
3196 return lttng_field_name_statedump(session, field, nesting);
3197}
3198
3199/*
3200 * Must be called with sessions_mutex held.
3201 */
3202static
3203int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
3204 const struct lttng_kernel_type_variant *type,
3205 size_t nesting,
3206 const char *prev_field_name)
3207{
3208 const char *tag_name;
3209 int ret;
3210 uint32_t i, nr_choices;
3211
3212 tag_name = type->tag_name;
3213 if (!tag_name)
3214 tag_name = prev_field_name;
3215 if (!tag_name)
3216 return -EINVAL;
3217 /*
3218 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3219 */
3220 if (type->alignment != 0)
3221 return -EINVAL;
3222 ret = print_tabs(session, nesting);
3223 if (ret)
3224 return ret;
3225 ret = lttng_metadata_printf(session,
3226 "variant <_%s> {\n",
3227 tag_name);
3228 if (ret)
3229 return ret;
3230 nr_choices = type->nr_choices;
3231 for (i = 0; i < nr_choices; i++) {
3232 const struct lttng_kernel_event_field *iter_field;
3233
3234 iter_field = type->choices[i];
3235 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3236 if (ret)
3237 return ret;
3238 }
3239 ret = print_tabs(session, nesting);
3240 if (ret)
3241 return ret;
3242 ret = lttng_metadata_printf(session,
3243 "}");
3244 return ret;
3245}
3246
3247/*
3248 * Must be called with sessions_mutex held.
3249 */
3250static
3251int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3252 const struct lttng_kernel_event_field *field,
3253 size_t nesting,
3254 const char *prev_field_name)
3255{
3256 int ret;
3257
3258 ret = _lttng_variant_type_statedump(session,
3259 lttng_kernel_get_type_variant(field->type), nesting,
3260 prev_field_name);
3261 if (ret)
3262 return ret;
3263 return lttng_field_name_statedump(session, field, nesting);
3264}
3265
3266/*
3267 * Must be called with sessions_mutex held.
3268 */
3269static
3270int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3271 const struct lttng_kernel_event_field *field,
3272 size_t nesting)
3273{
3274 int ret;
3275 const struct lttng_kernel_type_array *array_type;
3276 const struct lttng_kernel_type_common *elem_type;
3277
3278 array_type = lttng_kernel_get_type_array(field->type);
3279 WARN_ON_ONCE(!array_type);
3280
3281 if (array_type->alignment) {
3282 ret = print_tabs(session, nesting);
3283 if (ret)
3284 return ret;
3285 ret = lttng_metadata_printf(session,
3286 "struct { } align(%u) _%s_padding;\n",
3287 array_type->alignment * CHAR_BIT,
3288 field->name);
3289 if (ret)
3290 return ret;
3291 }
3292 /*
3293 * Nested compound types: Only array of structures and variants are
3294 * currently supported.
3295 */
3296 elem_type = array_type->elem_type;
3297 switch (elem_type->type) {
3298 case lttng_kernel_type_integer:
3299 case lttng_kernel_type_struct:
3300 case lttng_kernel_type_variant:
3301 ret = _lttng_type_statedump(session, elem_type,
3302 array_type->encoding, nesting);
3303 if (ret)
3304 return ret;
3305 break;
3306
3307 default:
3308 return -EINVAL;
3309 }
3310 ret = lttng_metadata_printf(session,
3311 " _%s[%u];\n",
3312 field->name,
3313 array_type->length);
3314 return ret;
3315}
3316
3317/*
3318 * Must be called with sessions_mutex held.
3319 */
3320static
3321int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3322 const struct lttng_kernel_event_field *field,
3323 size_t nesting,
3324 const char *prev_field_name)
3325{
3326 int ret;
3327 const char *length_name;
3328 const struct lttng_kernel_type_sequence *sequence_type;
3329 const struct lttng_kernel_type_common *elem_type;
3330
3331 sequence_type = lttng_kernel_get_type_sequence(field->type);
3332 WARN_ON_ONCE(!sequence_type);
3333
3334 length_name = sequence_type->length_name;
3335 if (!length_name)
3336 length_name = prev_field_name;
3337 if (!length_name)
3338 return -EINVAL;
3339
3340 if (sequence_type->alignment) {
3341 ret = print_tabs(session, nesting);
3342 if (ret)
3343 return ret;
3344 ret = lttng_metadata_printf(session,
3345 "struct { } align(%u) _%s_padding;\n",
3346 sequence_type->alignment * CHAR_BIT,
3347 field->name);
3348 if (ret)
3349 return ret;
3350 }
3351
3352 /*
3353 * Nested compound types: Only array of structures and variants are
3354 * currently supported.
3355 */
3356 elem_type = sequence_type->elem_type;
3357 switch (elem_type->type) {
3358 case lttng_kernel_type_integer:
3359 case lttng_kernel_type_struct:
3360 case lttng_kernel_type_variant:
3361 ret = _lttng_type_statedump(session, elem_type,
3362 sequence_type->encoding, nesting);
3363 if (ret)
3364 return ret;
3365 break;
3366
3367 default:
3368 return -EINVAL;
3369 }
3370 ret = lttng_metadata_printf(session,
3371 " _%s[ _%s ];\n",
3372 field->name,
3373 length_name);
3374 return ret;
3375}
3376
3377/*
3378 * Must be called with sessions_mutex held.
3379 */
3380static
3381int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3382 const struct lttng_kernel_type_enum *type,
3383 size_t nesting)
3384{
3385 const struct lttng_kernel_enum_desc *enum_desc;
3386 const struct lttng_kernel_type_common *container_type;
3387 int ret;
3388 unsigned int i, nr_entries;
3389
3390 container_type = type->container_type;
3391 if (container_type->type != lttng_kernel_type_integer) {
3392 ret = -EINVAL;
3393 goto end;
3394 }
3395 enum_desc = type->desc;
3396 nr_entries = enum_desc->nr_entries;
3397
3398 ret = print_tabs(session, nesting);
3399 if (ret)
3400 goto end;
3401 ret = lttng_metadata_printf(session, "enum : ");
3402 if (ret)
3403 goto end;
3404 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3405 lttng_kernel_string_encoding_none, 0);
3406 if (ret)
3407 goto end;
3408 ret = lttng_metadata_printf(session, " {\n");
3409 if (ret)
3410 goto end;
3411 /* Dump all entries */
3412 for (i = 0; i < nr_entries; i++) {
3413 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3414 int j, len;
3415
3416 ret = print_tabs(session, nesting + 1);
3417 if (ret)
3418 goto end;
3419 ret = lttng_metadata_printf(session,
3420 "\"");
3421 if (ret)
3422 goto end;
3423 len = strlen(entry->string);
3424 /* Escape the character '"' */
3425 for (j = 0; j < len; j++) {
3426 char c = entry->string[j];
3427
3428 switch (c) {
3429 case '"':
3430 ret = lttng_metadata_printf(session,
3431 "\\\"");
3432 break;
3433 case '\\':
3434 ret = lttng_metadata_printf(session,
3435 "\\\\");
3436 break;
3437 default:
3438 ret = lttng_metadata_printf(session,
3439 "%c", c);
3440 break;
3441 }
3442 if (ret)
3443 goto end;
3444 }
3445 ret = lttng_metadata_printf(session, "\"");
3446 if (ret)
3447 goto end;
3448
3449 if (entry->options.is_auto) {
3450 ret = lttng_metadata_printf(session, ",\n");
3451 if (ret)
3452 goto end;
3453 } else {
3454 ret = lttng_metadata_printf(session,
3455 " = ");
3456 if (ret)
3457 goto end;
3458 if (entry->start.signedness)
3459 ret = lttng_metadata_printf(session,
3460 "%lld", (long long) entry->start.value);
3461 else
3462 ret = lttng_metadata_printf(session,
3463 "%llu", entry->start.value);
3464 if (ret)
3465 goto end;
3466 if (entry->start.signedness == entry->end.signedness &&
3467 entry->start.value
3468 == entry->end.value) {
3469 ret = lttng_metadata_printf(session,
3470 ",\n");
3471 } else {
3472 if (entry->end.signedness) {
3473 ret = lttng_metadata_printf(session,
3474 " ... %lld,\n",
3475 (long long) entry->end.value);
3476 } else {
3477 ret = lttng_metadata_printf(session,
3478 " ... %llu,\n",
3479 entry->end.value);
3480 }
3481 }
3482 if (ret)
3483 goto end;
3484 }
3485 }
3486 ret = print_tabs(session, nesting);
3487 if (ret)
3488 goto end;
3489 ret = lttng_metadata_printf(session, "}");
3490end:
3491 return ret;
3492}
3493
3494/*
3495 * Must be called with sessions_mutex held.
3496 */
3497static
3498int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3499 const struct lttng_kernel_event_field *field,
3500 size_t nesting)
3501{
3502 int ret;
3503 const struct lttng_kernel_type_enum *enum_type;
3504
3505 enum_type = lttng_kernel_get_type_enum(field->type);
3506 WARN_ON_ONCE(!enum_type);
3507 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3508 if (ret)
3509 return ret;
3510 return lttng_field_name_statedump(session, field, nesting);
3511}
3512
3513static
3514int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3515 const struct lttng_kernel_event_field *field,
3516 size_t nesting)
3517{
3518 int ret;
3519
3520 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3521 lttng_kernel_string_encoding_none, nesting);
3522 if (ret)
3523 return ret;
3524 return lttng_field_name_statedump(session, field, nesting);
3525}
3526
3527static
3528int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3529 const struct lttng_kernel_type_string *type,
3530 size_t nesting)
3531{
3532 int ret;
3533
3534 /* Default encoding is UTF8 */
3535 ret = print_tabs(session, nesting);
3536 if (ret)
3537 return ret;
3538 ret = lttng_metadata_printf(session,
3539 "string%s",
3540 type->encoding == lttng_kernel_string_encoding_ASCII ?
3541 " { encoding = ASCII; }" : "");
3542 return ret;
3543}
3544
3545static
3546int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3547 const struct lttng_kernel_event_field *field,
3548 size_t nesting)
3549{
3550 const struct lttng_kernel_type_string *string_type;
3551 int ret;
3552
3553 string_type = lttng_kernel_get_type_string(field->type);
3554 WARN_ON_ONCE(!string_type);
3555 ret = _lttng_string_type_statedump(session, string_type, nesting);
3556 if (ret)
3557 return ret;
3558 return lttng_field_name_statedump(session, field, nesting);
3559}
3560
3561/*
3562 * Must be called with sessions_mutex held.
3563 */
3564static
3565int _lttng_type_statedump(struct lttng_kernel_session *session,
3566 const struct lttng_kernel_type_common *type,
3567 enum lttng_kernel_string_encoding parent_encoding,
3568 size_t nesting)
3569{
3570 int ret = 0;
3571
3572 switch (type->type) {
3573 case lttng_kernel_type_integer:
3574 ret = _lttng_integer_type_statedump(session,
3575 lttng_kernel_get_type_integer(type),
3576 parent_encoding, nesting);
3577 break;
3578 case lttng_kernel_type_enum:
3579 ret = _lttng_enum_type_statedump(session,
3580 lttng_kernel_get_type_enum(type),
3581 nesting);
3582 break;
3583 case lttng_kernel_type_string:
3584 ret = _lttng_string_type_statedump(session,
3585 lttng_kernel_get_type_string(type),
3586 nesting);
3587 break;
3588 case lttng_kernel_type_struct:
3589 ret = _lttng_struct_type_statedump(session,
3590 lttng_kernel_get_type_struct(type),
3591 nesting);
3592 break;
3593 case lttng_kernel_type_variant:
3594 ret = _lttng_variant_type_statedump(session,
3595 lttng_kernel_get_type_variant(type),
3596 nesting, NULL);
3597 break;
3598
3599 /* Nested arrays and sequences are not supported yet. */
3600 case lttng_kernel_type_array:
3601 case lttng_kernel_type_sequence:
3602 default:
3603 WARN_ON_ONCE(1);
3604 return -EINVAL;
3605 }
3606 return ret;
3607}
3608
3609/*
3610 * Must be called with sessions_mutex held.
3611 */
3612static
3613int _lttng_field_statedump(struct lttng_kernel_session *session,
3614 const struct lttng_kernel_event_field *field,
3615 size_t nesting,
3616 const char **prev_field_name_p)
3617{
3618 const char *prev_field_name = NULL;
3619 int ret = 0;
3620
3621 if (prev_field_name_p)
3622 prev_field_name = *prev_field_name_p;
3623 switch (field->type->type) {
3624 case lttng_kernel_type_integer:
3625 ret = _lttng_integer_field_statedump(session, field, nesting);
3626 break;
3627 case lttng_kernel_type_enum:
3628 ret = _lttng_enum_field_statedump(session, field, nesting);
3629 break;
3630 case lttng_kernel_type_string:
3631 ret = _lttng_string_field_statedump(session, field, nesting);
3632 break;
3633 case lttng_kernel_type_struct:
3634 ret = _lttng_struct_field_statedump(session, field, nesting);
3635 break;
3636 case lttng_kernel_type_array:
3637 ret = _lttng_array_field_statedump(session, field, nesting);
3638 break;
3639 case lttng_kernel_type_sequence:
3640 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3641 break;
3642 case lttng_kernel_type_variant:
3643 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3644 break;
3645
3646 default:
3647 WARN_ON_ONCE(1);
3648 return -EINVAL;
3649 }
3650 if (prev_field_name_p)
3651 *prev_field_name_p = field->name;
3652 return ret;
3653}
3654
3655static
3656int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3657 struct lttng_kernel_ctx *ctx)
3658{
3659 const char *prev_field_name = NULL;
3660 int ret = 0;
3661 int i;
3662
3663 if (!ctx)
3664 return 0;
3665 for (i = 0; i < ctx->nr_fields; i++) {
3666 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3667
3668 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3669 if (ret)
3670 return ret;
3671 }
3672 return ret;
3673}
3674
3675static
3676int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3677 struct lttng_kernel_event_recorder *event_recorder)
3678{
3679 const char *prev_field_name = NULL;
3680 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3681 int ret = 0;
3682 int i;
3683
3684 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3685 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3686
3687 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3688 if (ret)
3689 return ret;
3690 }
3691 return ret;
3692}
3693
3694/*
3695 * Must be called with sessions_mutex held.
3696 * The entire event metadata is printed as a single atomic metadata
3697 * transaction.
3698 */
3699static
3700int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
3701 struct lttng_kernel_channel_buffer *chan,
3702 struct lttng_kernel_event_recorder *event_recorder)
3703{
3704 int ret = 0;
3705
3706 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3707 return 0;
3708 if (chan->priv->channel_type == METADATA_CHANNEL)
3709 return 0;
3710
3711 lttng_metadata_begin(session);
3712
3713 ret = lttng_metadata_printf(session,
3714 "event {\n"
3715 " name = \"%s\";\n"
3716 " id = %u;\n"
3717 " stream_id = %u;\n",
3718 event_recorder->priv->parent.desc->event_name,
3719 event_recorder->priv->id,
3720 event_recorder->chan->priv->id);
3721 if (ret)
3722 goto end;
3723
3724 ret = lttng_metadata_printf(session,
3725 " fields := struct {\n"
3726 );
3727 if (ret)
3728 goto end;
3729
3730 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3731 if (ret)
3732 goto end;
3733
3734 /*
3735 * LTTng space reservation can only reserve multiples of the
3736 * byte size.
3737 */
3738 ret = lttng_metadata_printf(session,
3739 " };\n"
3740 "};\n\n");
3741 if (ret)
3742 goto end;
3743
3744 event_recorder->priv->metadata_dumped = 1;
3745end:
3746 lttng_metadata_end(session);
3747 return ret;
3748
3749}
3750
3751/*
3752 * Must be called with sessions_mutex held.
3753 * The entire channel metadata is printed as a single atomic metadata
3754 * transaction.
3755 */
3756static
3757int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3758 struct lttng_kernel_channel_buffer *chan)
3759{
3760 int ret = 0;
3761
3762 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3763 return 0;
3764
3765 if (chan->priv->channel_type == METADATA_CHANNEL)
3766 return 0;
3767
3768 lttng_metadata_begin(session);
3769
3770 WARN_ON_ONCE(!chan->priv->header_type);
3771 ret = lttng_metadata_printf(session,
3772 "stream {\n"
3773 " id = %u;\n"
3774 " event.header := %s;\n"
3775 " packet.context := struct packet_context;\n",
3776 chan->priv->id,
3777 chan->priv->header_type == 1 ? "struct event_header_compact" :
3778 "struct event_header_large");
3779 if (ret)
3780 goto end;
3781
3782 if (chan->priv->ctx) {
3783 ret = lttng_metadata_printf(session,
3784 " event.context := struct {\n");
3785 if (ret)
3786 goto end;
3787 }
3788 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3789 if (ret)
3790 goto end;
3791 if (chan->priv->ctx) {
3792 ret = lttng_metadata_printf(session,
3793 " };\n");
3794 if (ret)
3795 goto end;
3796 }
3797
3798 ret = lttng_metadata_printf(session,
3799 "};\n\n");
3800
3801 chan->priv->metadata_dumped = 1;
3802end:
3803 lttng_metadata_end(session);
3804 return ret;
3805}
3806
3807/*
3808 * Must be called with sessions_mutex held.
3809 */
3810static
3811int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3812{
3813 return lttng_metadata_printf(session,
3814 "struct packet_context {\n"
3815 " uint64_clock_monotonic_t timestamp_begin;\n"
3816 " uint64_clock_monotonic_t timestamp_end;\n"
3817 " uint64_t content_size;\n"
3818 " uint64_t packet_size;\n"
3819 " uint64_t packet_seq_num;\n"
3820 " unsigned long events_discarded;\n"
3821 " uint32_t cpu_id;\n"
3822 "};\n\n"
3823 );
3824}
3825
3826/*
3827 * Compact header:
3828 * id: range: 0 - 30.
3829 * id 31 is reserved to indicate an extended header.
3830 *
3831 * Large header:
3832 * id: range: 0 - 65534.
3833 * id 65535 is reserved to indicate an extended header.
3834 *
3835 * Must be called with sessions_mutex held.
3836 */
3837static
3838int _lttng_event_header_declare(struct lttng_kernel_session *session)
3839{
3840 return lttng_metadata_printf(session,
3841 "struct event_header_compact {\n"
3842 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3843 " variant <id> {\n"
3844 " struct {\n"
3845 " uint27_clock_monotonic_t timestamp;\n"
3846 " } compact;\n"
3847 " struct {\n"
3848 " uint32_t id;\n"
3849 " uint64_clock_monotonic_t timestamp;\n"
3850 " } extended;\n"
3851 " } v;\n"
3852 "} align(%u);\n"
3853 "\n"
3854 "struct event_header_large {\n"
3855 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3856 " variant <id> {\n"
3857 " struct {\n"
3858 " uint32_clock_monotonic_t timestamp;\n"
3859 " } compact;\n"
3860 " struct {\n"
3861 " uint32_t id;\n"
3862 " uint64_clock_monotonic_t timestamp;\n"
3863 " } extended;\n"
3864 " } v;\n"
3865 "} align(%u);\n\n",
3866 lttng_alignof(uint32_t) * CHAR_BIT,
3867 lttng_alignof(uint16_t) * CHAR_BIT
3868 );
3869}
3870
3871 /*
3872 * Approximation of NTP time of day to clock monotonic correlation,
3873 * taken at start of trace.
3874 * Yes, this is only an approximation. Yes, we can (and will) do better
3875 * in future versions.
3876 * This function may return a negative offset. It may happen if the
3877 * system sets the REALTIME clock to 0 after boot.
3878 *
3879 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3880 * y2038 compliant.
3881 */
3882static
3883int64_t measure_clock_offset(void)
3884{
3885 uint64_t monotonic_avg, monotonic[2], realtime;
3886 uint64_t tcf = trace_clock_freq();
3887 int64_t offset;
3888 unsigned long flags;
3889#ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3890 struct timespec64 rts = { 0, 0 };
3891#else
3892 struct timespec rts = { 0, 0 };
3893#endif
3894
3895 /* Disable interrupts to increase correlation precision. */
3896 local_irq_save(flags);
3897 monotonic[0] = trace_clock_read64();
3898#ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3899 ktime_get_real_ts64(&rts);
3900#else
3901 getnstimeofday(&rts);
3902#endif
3903 monotonic[1] = trace_clock_read64();
3904 local_irq_restore(flags);
3905
3906 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3907 realtime = (uint64_t) rts.tv_sec * tcf;
3908 if (tcf == NSEC_PER_SEC) {
3909 realtime += rts.tv_nsec;
3910 } else {
3911 uint64_t n = rts.tv_nsec * tcf;
3912
3913 do_div(n, NSEC_PER_SEC);
3914 realtime += n;
3915 }
3916 offset = (int64_t) realtime - monotonic_avg;
3917 return offset;
3918}
3919
3920static
3921int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3922{
3923 int ret = 0;
3924 size_t i;
3925 char cur;
3926
3927 i = 0;
3928 cur = string[i];
3929 while (cur != '\0') {
3930 switch (cur) {
3931 case '\n':
3932 ret = lttng_metadata_printf(session, "%s", "\\n");
3933 break;
3934 case '\\':
3935 case '"':
3936 ret = lttng_metadata_printf(session, "%c", '\\');
3937 if (ret)
3938 goto error;
3939 /* We still print the current char */
3940 lttng_fallthrough;
3941 default:
3942 ret = lttng_metadata_printf(session, "%c", cur);
3943 break;
3944 }
3945
3946 if (ret)
3947 goto error;
3948
3949 cur = string[++i];
3950 }
3951error:
3952 return ret;
3953}
3954
3955static
3956int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3957 const char *field_value)
3958{
3959 int ret;
3960
3961 ret = lttng_metadata_printf(session, " %s = \"", field);
3962 if (ret)
3963 goto error;
3964
3965 ret = print_escaped_ctf_string(session, field_value);
3966 if (ret)
3967 goto error;
3968
3969 ret = lttng_metadata_printf(session, "\";\n");
3970
3971error:
3972 return ret;
3973}
3974
3975/*
3976 * Output metadata into this session's metadata buffers.
3977 * Must be called with sessions_mutex held.
3978 */
3979static
3980int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3981{
3982 unsigned char *uuid_c = session->priv->uuid.b;
3983 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3984 const char *product_uuid;
3985 struct lttng_kernel_channel_buffer_private *chan_priv;
3986 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3987 int ret = 0;
3988
3989 if (!LTTNG_READ_ONCE(session->active))
3990 return 0;
3991
3992 lttng_metadata_begin(session);
3993
3994 if (session->priv->metadata_dumped)
3995 goto skip_session;
3996
3997 snprintf(uuid_s, sizeof(uuid_s),
3998 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3999 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
4000 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
4001 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
4002 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
4003
4004 ret = lttng_metadata_printf(session,
4005 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
4006 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
4007 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
4008 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
4009 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
4010 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
4011 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
4012 "\n"
4013 "trace {\n"
4014 " major = %u;\n"
4015 " minor = %u;\n"
4016 " uuid = \"%s\";\n"
4017 " byte_order = %s;\n"
4018 " packet.header := struct {\n"
4019 " uint32_t magic;\n"
4020 " uint8_t uuid[16];\n"
4021 " uint32_t stream_id;\n"
4022 " uint64_t stream_instance_id;\n"
4023 " };\n"
4024 "};\n\n",
4025 lttng_alignof(uint8_t) * CHAR_BIT,
4026 lttng_alignof(uint16_t) * CHAR_BIT,
4027 lttng_alignof(uint32_t) * CHAR_BIT,
4028 lttng_alignof(uint64_t) * CHAR_BIT,
4029 sizeof(unsigned long) * CHAR_BIT,
4030 lttng_alignof(unsigned long) * CHAR_BIT,
4031 CTF_SPEC_MAJOR,
4032 CTF_SPEC_MINOR,
4033 uuid_s,
4034#if __BYTE_ORDER == __BIG_ENDIAN
4035 "be"
4036#else
4037 "le"
4038#endif
4039 );
4040 if (ret)
4041 goto end;
4042
4043 ret = lttng_metadata_printf(session,
4044 "env {\n"
4045 " hostname = \"%s\";\n"
4046 " domain = \"kernel\";\n"
4047 " sysname = \"%s\";\n"
4048 " kernel_release = \"%s\";\n"
4049 " kernel_version = \"%s\";\n"
4050 " tracer_name = \"lttng-modules\";\n"
4051 " tracer_major = %d;\n"
4052 " tracer_minor = %d;\n"
4053 " tracer_patchlevel = %d;\n"
4054 " trace_buffering_scheme = \"global\";\n",
4055 current->nsproxy->uts_ns->name.nodename,
4056 utsname()->sysname,
4057 utsname()->release,
4058 utsname()->version,
4059 LTTNG_MODULES_MAJOR_VERSION,
4060 LTTNG_MODULES_MINOR_VERSION,
4061 LTTNG_MODULES_PATCHLEVEL_VERSION
4062 );
4063 if (ret)
4064 goto end;
4065
4066 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
4067 if (ret)
4068 goto end;
4069 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
4070 session->priv->creation_time);
4071 if (ret)
4072 goto end;
4073
4074 /* Add the product UUID to the 'env' section */
4075 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
4076 if (product_uuid) {
4077 ret = lttng_metadata_printf(session,
4078 " product_uuid = \"%s\";\n",
4079 product_uuid
4080 );
4081 if (ret)
4082 goto end;
4083 }
4084
4085 /* Close the 'env' section */
4086 ret = lttng_metadata_printf(session, "};\n\n");
4087 if (ret)
4088 goto end;
4089
4090 ret = lttng_metadata_printf(session,
4091 "clock {\n"
4092 " name = \"%s\";\n",
4093 trace_clock_name()
4094 );
4095 if (ret)
4096 goto end;
4097
4098 if (!trace_clock_uuid(clock_uuid_s)) {
4099 ret = lttng_metadata_printf(session,
4100 " uuid = \"%s\";\n",
4101 clock_uuid_s
4102 );
4103 if (ret)
4104 goto end;
4105 }
4106
4107 ret = lttng_metadata_printf(session,
4108 " description = \"%s\";\n"
4109 " freq = %llu; /* Frequency, in Hz */\n"
4110 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
4111 " offset = %lld;\n"
4112 "};\n\n",
4113 trace_clock_description(),
4114 (unsigned long long) trace_clock_freq(),
4115 (long long) measure_clock_offset()
4116 );
4117 if (ret)
4118 goto end;
4119
4120 ret = lttng_metadata_printf(session,
4121 "typealias integer {\n"
4122 " size = 27; align = 1; signed = false;\n"
4123 " map = clock.%s.value;\n"
4124 "} := uint27_clock_monotonic_t;\n"
4125 "\n"
4126 "typealias integer {\n"
4127 " size = 32; align = %u; signed = false;\n"
4128 " map = clock.%s.value;\n"
4129 "} := uint32_clock_monotonic_t;\n"
4130 "\n"
4131 "typealias integer {\n"
4132 " size = 64; align = %u; signed = false;\n"
4133 " map = clock.%s.value;\n"
4134 "} := uint64_clock_monotonic_t;\n\n",
4135 trace_clock_name(),
4136 lttng_alignof(uint32_t) * CHAR_BIT,
4137 trace_clock_name(),
4138 lttng_alignof(uint64_t) * CHAR_BIT,
4139 trace_clock_name()
4140 );
4141 if (ret)
4142 goto end;
4143
4144 ret = _lttng_stream_packet_context_declare(session);
4145 if (ret)
4146 goto end;
4147
4148 ret = _lttng_event_header_declare(session);
4149 if (ret)
4150 goto end;
4151
4152skip_session:
4153 list_for_each_entry(chan_priv, &session->priv->chan, node) {
4154 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
4155 if (ret)
4156 goto end;
4157 }
4158
4159 list_for_each_entry(event_recorder_priv, &session->priv->events, node) {
4160 ret = _lttng_event_metadata_statedump(session, event_recorder_priv->pub->chan,
4161 event_recorder_priv->pub);
4162 if (ret)
4163 goto end;
4164 }
4165 session->priv->metadata_dumped = 1;
4166end:
4167 lttng_metadata_end(session);
4168 return ret;
4169}
4170
4171/**
4172 * lttng_transport_register - LTT transport registration
4173 * @transport: transport structure
4174 *
4175 * Registers a transport which can be used as output to extract the data out of
4176 * LTTng. The module calling this registration function must ensure that no
4177 * trap-inducing code will be executed by the transport functions. E.g.
4178 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
4179 * is made visible to the transport function. This registration acts as a
4180 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
4181 * after its registration must it synchronize the TLBs.
4182 */
4183void lttng_transport_register(struct lttng_transport *transport)
4184{
4185 /*
4186 * Make sure no page fault can be triggered by the module about to be
4187 * registered. We deal with this here so we don't have to call
4188 * vmalloc_sync_mappings() in each module's init.
4189 */
4190 wrapper_vmalloc_sync_mappings();
4191
4192 mutex_lock(&sessions_mutex);
4193 list_add_tail(&transport->node, &lttng_transport_list);
4194 mutex_unlock(&sessions_mutex);
4195}
4196EXPORT_SYMBOL_GPL(lttng_transport_register);
4197
4198/**
4199 * lttng_transport_unregister - LTT transport unregistration
4200 * @transport: transport structure
4201 */
4202void lttng_transport_unregister(struct lttng_transport *transport)
4203{
4204 mutex_lock(&sessions_mutex);
4205 list_del(&transport->node);
4206 mutex_unlock(&sessions_mutex);
4207}
4208EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4209
4210void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4211{
4212 /*
4213 * Make sure no page fault can be triggered by the module about to be
4214 * registered. We deal with this here so we don't have to call
4215 * vmalloc_sync_mappings() in each module's init.
4216 */
4217 wrapper_vmalloc_sync_mappings();
4218
4219 mutex_lock(&sessions_mutex);
4220 list_add_tail(&transport->node, &lttng_counter_transport_list);
4221 mutex_unlock(&sessions_mutex);
4222}
4223EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4224
4225void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4226{
4227 mutex_lock(&sessions_mutex);
4228 list_del(&transport->node);
4229 mutex_unlock(&sessions_mutex);
4230}
4231EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4232
4233#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4234
4235enum cpuhp_state lttng_hp_prepare;
4236enum cpuhp_state lttng_hp_online;
4237
4238static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4239{
4240 struct lttng_cpuhp_node *lttng_node;
4241
4242 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4243 switch (lttng_node->component) {
4244 case LTTNG_RING_BUFFER_FRONTEND:
4245 return 0;
4246 case LTTNG_RING_BUFFER_BACKEND:
4247 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4248 case LTTNG_RING_BUFFER_ITER:
4249 return 0;
4250 case LTTNG_CONTEXT_PERF_COUNTERS:
4251 return 0;
4252 default:
4253 return -EINVAL;
4254 }
4255}
4256
4257static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4258{
4259 struct lttng_cpuhp_node *lttng_node;
4260
4261 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4262 switch (lttng_node->component) {
4263 case LTTNG_RING_BUFFER_FRONTEND:
4264 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4265 case LTTNG_RING_BUFFER_BACKEND:
4266 return 0;
4267 case LTTNG_RING_BUFFER_ITER:
4268 return 0;
4269 case LTTNG_CONTEXT_PERF_COUNTERS:
4270 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4271 default:
4272 return -EINVAL;
4273 }
4274}
4275
4276static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4277{
4278 struct lttng_cpuhp_node *lttng_node;
4279
4280 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4281 switch (lttng_node->component) {
4282 case LTTNG_RING_BUFFER_FRONTEND:
4283 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4284 case LTTNG_RING_BUFFER_BACKEND:
4285 return 0;
4286 case LTTNG_RING_BUFFER_ITER:
4287 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4288 case LTTNG_CONTEXT_PERF_COUNTERS:
4289 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4290 default:
4291 return -EINVAL;
4292 }
4293}
4294
4295static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4296{
4297 struct lttng_cpuhp_node *lttng_node;
4298
4299 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4300 switch (lttng_node->component) {
4301 case LTTNG_RING_BUFFER_FRONTEND:
4302 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4303 case LTTNG_RING_BUFFER_BACKEND:
4304 return 0;
4305 case LTTNG_RING_BUFFER_ITER:
4306 return 0;
4307 case LTTNG_CONTEXT_PERF_COUNTERS:
4308 return 0;
4309 default:
4310 return -EINVAL;
4311 }
4312}
4313
4314static int __init lttng_init_cpu_hotplug(void)
4315{
4316 int ret;
4317
4318 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4319 lttng_hotplug_prepare,
4320 lttng_hotplug_dead);
4321 if (ret < 0) {
4322 return ret;
4323 }
4324 lttng_hp_prepare = ret;
4325 lttng_rb_set_hp_prepare(ret);
4326
4327 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4328 lttng_hotplug_online,
4329 lttng_hotplug_offline);
4330 if (ret < 0) {
4331 cpuhp_remove_multi_state(lttng_hp_prepare);
4332 lttng_hp_prepare = 0;
4333 return ret;
4334 }
4335 lttng_hp_online = ret;
4336 lttng_rb_set_hp_online(ret);
4337
4338 return 0;
4339}
4340
4341static void __exit lttng_exit_cpu_hotplug(void)
4342{
4343 lttng_rb_set_hp_online(0);
4344 cpuhp_remove_multi_state(lttng_hp_online);
4345 lttng_rb_set_hp_prepare(0);
4346 cpuhp_remove_multi_state(lttng_hp_prepare);
4347}
4348
4349#else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4350static int lttng_init_cpu_hotplug(void)
4351{
4352 return 0;
4353}
4354static void lttng_exit_cpu_hotplug(void)
4355{
4356}
4357#endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4358
4359static int __init lttng_events_init(void)
4360{
4361 int ret;
4362
4363 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4364 if (ret)
4365 return ret;
4366 ret = wrapper_get_pfnblock_flags_mask_init();
4367 if (ret)
4368 return ret;
4369 ret = wrapper_get_pageblock_flags_mask_init();
4370 if (ret)
4371 return ret;
4372 ret = lttng_probes_init();
4373 if (ret)
4374 return ret;
4375 ret = lttng_context_init();
4376 if (ret)
4377 return ret;
4378 ret = lttng_tracepoint_init();
4379 if (ret)
4380 goto error_tp;
4381 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4382 if (!event_recorder_cache) {
4383 ret = -ENOMEM;
4384 goto error_kmem_event_recorder;
4385 }
4386 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4387 if (!event_recorder_private_cache) {
4388 ret = -ENOMEM;
4389 goto error_kmem_event_recorder_private;
4390 }
4391 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4392 if (!event_notifier_cache) {
4393 ret = -ENOMEM;
4394 goto error_kmem_event_notifier;
4395 }
4396 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4397 if (!event_notifier_private_cache) {
4398 ret = -ENOMEM;
4399 goto error_kmem_event_notifier_private;
4400 }
4401 ret = lttng_abi_init();
4402 if (ret)
4403 goto error_abi;
4404 ret = lttng_logger_init();
4405 if (ret)
4406 goto error_logger;
4407 ret = lttng_init_cpu_hotplug();
4408 if (ret)
4409 goto error_hotplug;
4410 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4411 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4412 __stringify(LTTNG_MODULES_MINOR_VERSION),
4413 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4414 LTTNG_MODULES_EXTRAVERSION,
4415 LTTNG_VERSION_NAME,
4416#ifdef LTTNG_EXTRA_VERSION_GIT
4417 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4418#else
4419 "",
4420#endif
4421#ifdef LTTNG_EXTRA_VERSION_NAME
4422 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4423#else
4424 "");
4425#endif
4426#ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
4427 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
4428#endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
4429 return 0;
4430
4431error_hotplug:
4432 lttng_logger_exit();
4433error_logger:
4434 lttng_abi_exit();
4435error_abi:
4436 kmem_cache_destroy(event_notifier_private_cache);
4437error_kmem_event_notifier_private:
4438 kmem_cache_destroy(event_notifier_cache);
4439error_kmem_event_notifier:
4440 kmem_cache_destroy(event_recorder_private_cache);
4441error_kmem_event_recorder_private:
4442 kmem_cache_destroy(event_recorder_cache);
4443error_kmem_event_recorder:
4444 lttng_tracepoint_exit();
4445error_tp:
4446 lttng_context_exit();
4447 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4448 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4449 __stringify(LTTNG_MODULES_MINOR_VERSION),
4450 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4451 LTTNG_MODULES_EXTRAVERSION,
4452 LTTNG_VERSION_NAME,
4453#ifdef LTTNG_EXTRA_VERSION_GIT
4454 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4455#else
4456 "",
4457#endif
4458#ifdef LTTNG_EXTRA_VERSION_NAME
4459 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4460#else
4461 "");
4462#endif
4463 return ret;
4464}
4465
4466module_init(lttng_events_init);
4467
4468static void __exit lttng_events_exit(void)
4469{
4470 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4471
4472 lttng_exit_cpu_hotplug();
4473 lttng_logger_exit();
4474 lttng_abi_exit();
4475 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4476 lttng_session_destroy(session_priv->pub);
4477 kmem_cache_destroy(event_recorder_cache);
4478 kmem_cache_destroy(event_recorder_private_cache);
4479 kmem_cache_destroy(event_notifier_cache);
4480 kmem_cache_destroy(event_notifier_private_cache);
4481 lttng_tracepoint_exit();
4482 lttng_context_exit();
4483 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4484 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4485 __stringify(LTTNG_MODULES_MINOR_VERSION),
4486 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4487 LTTNG_MODULES_EXTRAVERSION,
4488 LTTNG_VERSION_NAME,
4489#ifdef LTTNG_EXTRA_VERSION_GIT
4490 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4491#else
4492 "",
4493#endif
4494#ifdef LTTNG_EXTRA_VERSION_NAME
4495 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4496#else
4497 "");
4498#endif
4499}
4500
4501module_exit(lttng_events_exit);
4502
4503#include <generated/patches.h>
4504#ifdef LTTNG_EXTRA_VERSION_GIT
4505MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4506#endif
4507#ifdef LTTNG_EXTRA_VERSION_NAME
4508MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4509#endif
4510MODULE_LICENSE("GPL and additional rights");
4511MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4512MODULE_DESCRIPTION("LTTng tracer");
4513MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4514 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4515 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4516 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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