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0115debb755299b5f5def36c59338c320780ca57
[lttng-modules.git] / src / lttng-events.c
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 #define METADATA_CACHE_DEFAULT_SIZE 4096
53
54 static LIST_HEAD(sessions);
55 static LIST_HEAD(event_notifier_groups);
56 static LIST_HEAD(lttng_transport_list);
57 static LIST_HEAD(lttng_counter_transport_list);
58 /*
59 * Protect the sessions and metadata caches.
60 */
61 static DEFINE_MUTEX(sessions_mutex);
62 static struct kmem_cache *event_recorder_cache;
63 static struct kmem_cache *event_recorder_private_cache;
64 static struct kmem_cache *event_notifier_cache;
65 static struct kmem_cache *event_notifier_private_cache;
66
67 static void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session);
68 static void lttng_session_sync_event_enablers(struct lttng_kernel_session *session);
69 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
70 static void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler);
71
72 static void _lttng_event_destroy(struct lttng_kernel_event_common *event);
73 static void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan);
74 static int _lttng_event_unregister(struct lttng_kernel_event_common *event);
75 static
76 int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
77 struct lttng_kernel_channel_buffer *chan,
78 struct lttng_kernel_event_recorder *event);
79 static
80 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session);
81 static
82 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
83 static
84 int _lttng_type_statedump(struct lttng_kernel_session *session,
85 const struct lttng_kernel_type_common *type,
86 enum lttng_kernel_string_encoding parent_encoding,
87 size_t nesting);
88 static
89 int _lttng_field_statedump(struct lttng_kernel_session *session,
90 const struct lttng_kernel_event_field *field,
91 size_t nesting, const char **prev_field_name_p);
92
93 void synchronize_trace(void)
94 {
95 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0) || \
96 LTTNG_RHEL_KERNEL_RANGE(4,18,0,193,0,0, 4,19,0,0,0,0))
97 synchronize_rcu();
98 #else
99 synchronize_sched();
100 #endif
101
102 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
103 #ifdef CONFIG_PREEMPT_RT_FULL
104 synchronize_rcu();
105 #endif
106 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
107 #ifdef CONFIG_PREEMPT_RT
108 synchronize_rcu();
109 #endif
110 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
111 }
112
113 void lttng_lock_sessions(void)
114 {
115 mutex_lock(&sessions_mutex);
116 }
117
118 void lttng_unlock_sessions(void)
119 {
120 mutex_unlock(&sessions_mutex);
121 }
122
123 static struct lttng_transport *lttng_transport_find(const char *name)
124 {
125 struct lttng_transport *transport;
126
127 list_for_each_entry(transport, &lttng_transport_list, node) {
128 if (!strcmp(transport->name, name))
129 return transport;
130 }
131 return NULL;
132 }
133
134 /*
135 * Called with sessions lock held.
136 */
137 int lttng_session_active(void)
138 {
139 struct lttng_kernel_session_private *iter;
140
141 list_for_each_entry(iter, &sessions, list) {
142 if (iter->pub->active)
143 return 1;
144 }
145 return 0;
146 }
147
148 struct lttng_kernel_session *lttng_session_create(void)
149 {
150 struct lttng_kernel_session *session;
151 struct lttng_kernel_session_private *session_priv;
152 struct lttng_metadata_cache *metadata_cache;
153 int i;
154
155 mutex_lock(&sessions_mutex);
156 session = lttng_kvzalloc(sizeof(*session), GFP_KERNEL);
157 if (!session)
158 goto err;
159 session_priv = lttng_kvzalloc(sizeof(*session_priv), GFP_KERNEL);
160 if (!session_priv)
161 goto err_free_session;
162 session->priv = session_priv;
163 session_priv->pub = session;
164
165 INIT_LIST_HEAD(&session_priv->chan);
166 INIT_LIST_HEAD(&session_priv->events);
167 lttng_guid_gen(&session_priv->uuid);
168
169 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
170 GFP_KERNEL);
171 if (!metadata_cache)
172 goto err_free_session_private;
173 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
174 if (!metadata_cache->data)
175 goto err_free_cache;
176 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
177 kref_init(&metadata_cache->refcount);
178 mutex_init(&metadata_cache->lock);
179 session_priv->metadata_cache = metadata_cache;
180 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
181 memcpy(&metadata_cache->uuid, &session_priv->uuid,
182 sizeof(metadata_cache->uuid));
183 INIT_LIST_HEAD(&session_priv->enablers_head);
184 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
185 INIT_HLIST_HEAD(&session_priv->events_ht.table[i]);
186 list_add(&session_priv->list, &sessions);
187
188 if (lttng_id_tracker_init(&session->pid_tracker, session, TRACKER_PID))
189 goto tracker_alloc_error;
190 if (lttng_id_tracker_init(&session->vpid_tracker, session, TRACKER_VPID))
191 goto tracker_alloc_error;
192 if (lttng_id_tracker_init(&session->uid_tracker, session, TRACKER_UID))
193 goto tracker_alloc_error;
194 if (lttng_id_tracker_init(&session->vuid_tracker, session, TRACKER_VUID))
195 goto tracker_alloc_error;
196 if (lttng_id_tracker_init(&session->gid_tracker, session, TRACKER_GID))
197 goto tracker_alloc_error;
198 if (lttng_id_tracker_init(&session->vgid_tracker, session, TRACKER_VGID))
199 goto tracker_alloc_error;
200
201 mutex_unlock(&sessions_mutex);
202
203 return session;
204
205 tracker_alloc_error:
206 lttng_id_tracker_fini(&session->pid_tracker);
207 lttng_id_tracker_fini(&session->vpid_tracker);
208 lttng_id_tracker_fini(&session->uid_tracker);
209 lttng_id_tracker_fini(&session->vuid_tracker);
210 lttng_id_tracker_fini(&session->gid_tracker);
211 lttng_id_tracker_fini(&session->vgid_tracker);
212 err_free_cache:
213 kfree(metadata_cache);
214 err_free_session_private:
215 lttng_kvfree(session_priv);
216 err_free_session:
217 lttng_kvfree(session);
218 err:
219 mutex_unlock(&sessions_mutex);
220 return NULL;
221 }
222
223 static
224 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
225 {
226 struct lttng_counter_transport *transport;
227
228 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
229 if (!strcmp(transport->name, name))
230 return transport;
231 }
232 return NULL;
233 }
234
235 struct lttng_counter *lttng_kernel_counter_create(
236 const char *counter_transport_name,
237 size_t number_dimensions, const size_t *dimensions_sizes)
238 {
239 struct lttng_counter *counter = NULL;
240 struct lttng_counter_transport *counter_transport = NULL;
241
242 counter_transport = lttng_counter_transport_find(counter_transport_name);
243 if (!counter_transport) {
244 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
245 counter_transport_name);
246 goto notransport;
247 }
248 if (!try_module_get(counter_transport->owner)) {
249 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
250 goto notransport;
251 }
252
253 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
254 if (!counter)
255 goto nomem;
256
257 /* Create event notifier error counter. */
258 counter->ops = &counter_transport->ops;
259 counter->transport = counter_transport;
260
261 counter->counter = counter->ops->counter_create(
262 number_dimensions, dimensions_sizes, 0);
263 if (!counter->counter) {
264 goto create_error;
265 }
266
267 return counter;
268
269 create_error:
270 lttng_kvfree(counter);
271 nomem:
272 if (counter_transport)
273 module_put(counter_transport->owner);
274 notransport:
275 return NULL;
276 }
277
278 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
279 {
280 struct lttng_transport *transport = NULL;
281 struct lttng_event_notifier_group *event_notifier_group;
282 const char *transport_name = "relay-event-notifier";
283 size_t subbuf_size = 4096; //TODO
284 size_t num_subbuf = 16; //TODO
285 unsigned int switch_timer_interval = 0;
286 unsigned int read_timer_interval = 0;
287 int i;
288
289 mutex_lock(&sessions_mutex);
290
291 transport = lttng_transport_find(transport_name);
292 if (!transport) {
293 printk(KERN_WARNING "LTTng: transport %s not found\n",
294 transport_name);
295 goto notransport;
296 }
297 if (!try_module_get(transport->owner)) {
298 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
299 transport_name);
300 goto notransport;
301 }
302
303 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
304 GFP_KERNEL);
305 if (!event_notifier_group)
306 goto nomem;
307
308 /*
309 * Initialize the ring buffer used to store event notifier
310 * notifications.
311 */
312 event_notifier_group->ops = &transport->ops;
313 event_notifier_group->chan = transport->ops.priv->channel_create(
314 transport_name, event_notifier_group, NULL,
315 subbuf_size, num_subbuf, switch_timer_interval,
316 read_timer_interval);
317 if (!event_notifier_group->chan)
318 goto create_error;
319
320 event_notifier_group->transport = transport;
321
322 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
323 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
324 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
325 INIT_HLIST_HEAD(&event_notifier_group->events_ht.table[i]);
326
327 list_add(&event_notifier_group->node, &event_notifier_groups);
328
329 mutex_unlock(&sessions_mutex);
330
331 return event_notifier_group;
332
333 create_error:
334 lttng_kvfree(event_notifier_group);
335 nomem:
336 if (transport)
337 module_put(transport->owner);
338 notransport:
339 mutex_unlock(&sessions_mutex);
340 return NULL;
341 }
342
343 void metadata_cache_destroy(struct kref *kref)
344 {
345 struct lttng_metadata_cache *cache =
346 container_of(kref, struct lttng_metadata_cache, refcount);
347 vfree(cache->data);
348 kfree(cache);
349 }
350
351 void lttng_session_destroy(struct lttng_kernel_session *session)
352 {
353 struct lttng_kernel_channel_buffer_private *chan_priv, *tmpchan_priv;
354 struct lttng_kernel_event_recorder_private *event_recorder_priv, *tmpevent_recorder_priv;
355 struct lttng_metadata_stream *metadata_stream;
356 struct lttng_event_enabler_common *event_enabler, *tmp_event_enabler;
357 int ret;
358
359 mutex_lock(&sessions_mutex);
360 WRITE_ONCE(session->active, 0);
361 list_for_each_entry(chan_priv, &session->priv->chan, node) {
362 ret = lttng_syscalls_unregister_syscall_table(&chan_priv->parent.syscall_table);
363 WARN_ON(ret);
364 }
365 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
366 ret = _lttng_event_unregister(&event_recorder_priv->pub->parent);
367 WARN_ON(ret);
368 }
369 synchronize_trace(); /* Wait for in-flight events to complete */
370 list_for_each_entry(chan_priv, &session->priv->chan, node) {
371 ret = lttng_syscalls_destroy_syscall_table(&chan_priv->parent.syscall_table);
372 WARN_ON(ret);
373 }
374 list_for_each_entry_safe(event_enabler, tmp_event_enabler, &session->priv->enablers_head, node)
375 lttng_event_enabler_destroy(event_enabler);
376 list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv, &session->priv->events, parent.node)
377 _lttng_event_destroy(&event_recorder_priv->pub->parent);
378 list_for_each_entry_safe(chan_priv, tmpchan_priv, &session->priv->chan, node) {
379 BUG_ON(chan_priv->channel_type == METADATA_CHANNEL);
380 _lttng_channel_destroy(chan_priv->pub);
381 }
382 mutex_lock(&session->priv->metadata_cache->lock);
383 list_for_each_entry(metadata_stream, &session->priv->metadata_cache->metadata_stream, list)
384 _lttng_metadata_channel_hangup(metadata_stream);
385 mutex_unlock(&session->priv->metadata_cache->lock);
386 lttng_id_tracker_fini(&session->pid_tracker);
387 lttng_id_tracker_fini(&session->vpid_tracker);
388 lttng_id_tracker_fini(&session->uid_tracker);
389 lttng_id_tracker_fini(&session->vuid_tracker);
390 lttng_id_tracker_fini(&session->gid_tracker);
391 lttng_id_tracker_fini(&session->vgid_tracker);
392 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
393 list_del(&session->priv->list);
394 mutex_unlock(&sessions_mutex);
395 lttng_kvfree(session->priv);
396 lttng_kvfree(session);
397 }
398
399 void lttng_event_notifier_group_destroy(
400 struct lttng_event_notifier_group *event_notifier_group)
401 {
402 struct lttng_event_enabler_common *event_enabler, *tmp_event_enabler;
403 struct lttng_kernel_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
404 int ret;
405
406 if (!event_notifier_group)
407 return;
408
409 mutex_lock(&sessions_mutex);
410
411 ret = lttng_syscalls_unregister_syscall_table(&event_notifier_group->syscall_table);
412 WARN_ON(ret);
413
414 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
415 &event_notifier_group->event_notifiers_head, parent.node) {
416 ret = _lttng_event_unregister(&event_notifier_priv->pub->parent);
417 WARN_ON(ret);
418 }
419
420 /* Wait for in-flight event notifier to complete */
421 synchronize_trace();
422
423 irq_work_sync(&event_notifier_group->wakeup_pending);
424
425 ret = lttng_syscalls_destroy_syscall_table(&event_notifier_group->syscall_table);
426 WARN_ON(ret);
427
428 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
429 &event_notifier_group->enablers_head, node)
430 lttng_event_enabler_destroy(event_enabler);
431
432 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
433 &event_notifier_group->event_notifiers_head, parent.node)
434 _lttng_event_destroy(&event_notifier_priv->pub->parent);
435
436 if (event_notifier_group->error_counter) {
437 struct lttng_counter *error_counter = event_notifier_group->error_counter;
438
439 error_counter->ops->counter_destroy(error_counter->counter);
440 module_put(error_counter->transport->owner);
441 lttng_kvfree(error_counter);
442 event_notifier_group->error_counter = NULL;
443 }
444
445 event_notifier_group->ops->priv->channel_destroy(event_notifier_group->chan);
446 module_put(event_notifier_group->transport->owner);
447 list_del(&event_notifier_group->node);
448
449 mutex_unlock(&sessions_mutex);
450 lttng_kvfree(event_notifier_group);
451 }
452
453 int lttng_session_statedump(struct lttng_kernel_session *session)
454 {
455 int ret;
456
457 mutex_lock(&sessions_mutex);
458 ret = lttng_statedump_start(session);
459 mutex_unlock(&sessions_mutex);
460 return ret;
461 }
462
463 int lttng_session_enable(struct lttng_kernel_session *session)
464 {
465 int ret = 0;
466 struct lttng_kernel_channel_buffer_private *chan_priv;
467
468 mutex_lock(&sessions_mutex);
469 if (session->active) {
470 ret = -EBUSY;
471 goto end;
472 }
473
474 /* Set transient enabler state to "enabled" */
475 session->priv->tstate = 1;
476
477 /* We need to sync enablers with session before activation. */
478 lttng_session_sync_event_enablers(session);
479
480 /*
481 * Snapshot the number of events per channel to know the type of header
482 * we need to use.
483 */
484 list_for_each_entry(chan_priv, &session->priv->chan, node) {
485 if (chan_priv->header_type)
486 continue; /* don't change it if session stop/restart */
487 if (chan_priv->free_event_id < 31)
488 chan_priv->header_type = 1; /* compact */
489 else
490 chan_priv->header_type = 2; /* large */
491 }
492
493 /* Clear each stream's quiescent state. */
494 list_for_each_entry(chan_priv, &session->priv->chan, node) {
495 if (chan_priv->channel_type != METADATA_CHANNEL)
496 lib_ring_buffer_clear_quiescent_channel(chan_priv->rb_chan);
497 }
498
499 WRITE_ONCE(session->active, 1);
500 WRITE_ONCE(session->priv->been_active, 1);
501 ret = _lttng_session_metadata_statedump(session);
502 if (ret) {
503 WRITE_ONCE(session->active, 0);
504 goto end;
505 }
506 ret = lttng_statedump_start(session);
507 if (ret)
508 WRITE_ONCE(session->active, 0);
509 end:
510 mutex_unlock(&sessions_mutex);
511 return ret;
512 }
513
514 int lttng_session_disable(struct lttng_kernel_session *session)
515 {
516 int ret = 0;
517 struct lttng_kernel_channel_buffer_private *chan_priv;
518
519 mutex_lock(&sessions_mutex);
520 if (!session->active) {
521 ret = -EBUSY;
522 goto end;
523 }
524 WRITE_ONCE(session->active, 0);
525
526 /* Set transient enabler state to "disabled" */
527 session->priv->tstate = 0;
528 lttng_session_sync_event_enablers(session);
529
530 /* Set each stream's quiescent state. */
531 list_for_each_entry(chan_priv, &session->priv->chan, node) {
532 if (chan_priv->channel_type != METADATA_CHANNEL)
533 lib_ring_buffer_set_quiescent_channel(chan_priv->rb_chan);
534 }
535 end:
536 mutex_unlock(&sessions_mutex);
537 return ret;
538 }
539
540 int lttng_session_metadata_regenerate(struct lttng_kernel_session *session)
541 {
542 int ret = 0;
543 struct lttng_kernel_channel_buffer_private *chan_priv;
544 struct lttng_kernel_event_recorder_private *event_recorder_priv;
545 struct lttng_metadata_cache *cache = session->priv->metadata_cache;
546 struct lttng_metadata_stream *stream;
547
548 mutex_lock(&sessions_mutex);
549 if (!session->active) {
550 ret = -EBUSY;
551 goto end;
552 }
553
554 mutex_lock(&cache->lock);
555 memset(cache->data, 0, cache->cache_alloc);
556 cache->metadata_written = 0;
557 cache->version++;
558 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list) {
559 stream->metadata_out = 0;
560 stream->metadata_in = 0;
561 }
562 mutex_unlock(&cache->lock);
563
564 session->priv->metadata_dumped = 0;
565 list_for_each_entry(chan_priv, &session->priv->chan, node) {
566 chan_priv->metadata_dumped = 0;
567 }
568
569 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
570 event_recorder_priv->metadata_dumped = 0;
571 }
572
573 ret = _lttng_session_metadata_statedump(session);
574
575 end:
576 mutex_unlock(&sessions_mutex);
577 return ret;
578 }
579
580 static
581 bool is_channel_buffer_metadata(struct lttng_kernel_channel_common *channel)
582 {
583 struct lttng_kernel_channel_buffer *chan_buf;
584
585 if (channel->type != LTTNG_KERNEL_CHANNEL_TYPE_BUFFER)
586 return false;
587 chan_buf = container_of(channel, struct lttng_kernel_channel_buffer, parent);
588 if (chan_buf->priv->channel_type == METADATA_CHANNEL)
589 return true;
590 return false;
591 }
592
593 int lttng_channel_enable(struct lttng_kernel_channel_common *channel)
594 {
595 int ret = 0;
596
597 mutex_lock(&sessions_mutex);
598 if (is_channel_buffer_metadata(channel)) {
599 ret = -EPERM;
600 goto end;
601 }
602 if (channel->enabled) {
603 ret = -EEXIST;
604 goto end;
605 }
606 /* Set transient enabler state to "enabled" */
607 channel->priv->tstate = 1;
608 lttng_session_sync_event_enablers(channel->session);
609 /* Set atomically the state to "enabled" */
610 WRITE_ONCE(channel->enabled, 1);
611 end:
612 mutex_unlock(&sessions_mutex);
613 return ret;
614 }
615
616 int lttng_channel_disable(struct lttng_kernel_channel_common *channel)
617 {
618 int ret = 0;
619
620 mutex_lock(&sessions_mutex);
621 if (is_channel_buffer_metadata(channel)) {
622 ret = -EPERM;
623 goto end;
624 }
625 if (!channel->enabled) {
626 ret = -EEXIST;
627 goto end;
628 }
629 /* Set atomically the state to "disabled" */
630 WRITE_ONCE(channel->enabled, 0);
631 /* Set transient enabler state to "enabled" */
632 channel->priv->tstate = 0;
633 lttng_session_sync_event_enablers(channel->session);
634 end:
635 mutex_unlock(&sessions_mutex);
636 return ret;
637 }
638
639 int lttng_event_enable(struct lttng_kernel_event_common *event)
640 {
641 int ret = 0;
642
643 mutex_lock(&sessions_mutex);
644 switch (event->type) {
645 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
646 {
647 struct lttng_kernel_event_recorder *event_recorder =
648 container_of(event, struct lttng_kernel_event_recorder, parent);
649
650 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
651 ret = -EPERM;
652 goto end;
653 }
654 break;
655 }
656 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
657 switch (event->priv->instrumentation) {
658 case LTTNG_KERNEL_ABI_KRETPROBE:
659 ret = -EINVAL;
660 goto end;
661 default:
662 break;
663 }
664 break;
665 default:
666 break;
667 }
668
669 if (event->enabled) {
670 ret = -EEXIST;
671 goto end;
672 }
673 switch (event->priv->instrumentation) {
674 case LTTNG_KERNEL_ABI_TRACEPOINT:
675 lttng_fallthrough;
676 case LTTNG_KERNEL_ABI_SYSCALL:
677 ret = -EINVAL;
678 break;
679
680 case LTTNG_KERNEL_ABI_KPROBE:
681 lttng_fallthrough;
682 case LTTNG_KERNEL_ABI_UPROBE:
683 WRITE_ONCE(event->enabled, 1);
684 break;
685
686 case LTTNG_KERNEL_ABI_KRETPROBE:
687 ret = lttng_kretprobes_event_enable_state(event, 1);
688 break;
689
690 case LTTNG_KERNEL_ABI_FUNCTION:
691 lttng_fallthrough;
692 case LTTNG_KERNEL_ABI_NOOP:
693 lttng_fallthrough;
694 default:
695 WARN_ON_ONCE(1);
696 ret = -EINVAL;
697 }
698 end:
699 mutex_unlock(&sessions_mutex);
700 return ret;
701 }
702
703 int lttng_event_disable(struct lttng_kernel_event_common *event)
704 {
705 int ret = 0;
706
707 mutex_lock(&sessions_mutex);
708 switch (event->type) {
709 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
710 {
711 struct lttng_kernel_event_recorder *event_recorder =
712 container_of(event, struct lttng_kernel_event_recorder, parent);
713
714 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
715 ret = -EPERM;
716 goto end;
717 }
718 break;
719 }
720 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
721 switch (event->priv->instrumentation) {
722 case LTTNG_KERNEL_ABI_KRETPROBE:
723 ret = -EINVAL;
724 goto end;
725 default:
726 break;
727 }
728 break;
729 default:
730 break;
731 }
732
733 if (!event->enabled) {
734 ret = -EEXIST;
735 goto end;
736 }
737 switch (event->priv->instrumentation) {
738 case LTTNG_KERNEL_ABI_TRACEPOINT:
739 lttng_fallthrough;
740 case LTTNG_KERNEL_ABI_SYSCALL:
741 ret = -EINVAL;
742 break;
743
744 case LTTNG_KERNEL_ABI_KPROBE:
745 lttng_fallthrough;
746 case LTTNG_KERNEL_ABI_UPROBE:
747 WRITE_ONCE(event->enabled, 0);
748 break;
749
750 case LTTNG_KERNEL_ABI_KRETPROBE:
751 ret = lttng_kretprobes_event_enable_state(event, 0);
752 break;
753
754 case LTTNG_KERNEL_ABI_FUNCTION:
755 lttng_fallthrough;
756 case LTTNG_KERNEL_ABI_NOOP:
757 lttng_fallthrough;
758 default:
759 WARN_ON_ONCE(1);
760 ret = -EINVAL;
761 }
762 end:
763 mutex_unlock(&sessions_mutex);
764 return ret;
765 }
766
767 struct lttng_kernel_channel_buffer *lttng_channel_buffer_create(struct lttng_kernel_session *session,
768 const char *transport_name,
769 void *buf_addr,
770 size_t subbuf_size, size_t num_subbuf,
771 unsigned int switch_timer_interval,
772 unsigned int read_timer_interval,
773 enum channel_type channel_type)
774 {
775 struct lttng_kernel_channel_buffer *chan;
776 struct lttng_kernel_channel_buffer_private *chan_priv;
777 struct lttng_transport *transport = NULL;
778
779 mutex_lock(&sessions_mutex);
780 if (session->priv->been_active && channel_type != METADATA_CHANNEL)
781 goto active; /* Refuse to add channel to active session */
782 transport = lttng_transport_find(transport_name);
783 if (!transport) {
784 printk(KERN_WARNING "LTTng: transport %s not found\n",
785 transport_name);
786 goto notransport;
787 }
788 if (!try_module_get(transport->owner)) {
789 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
790 goto notransport;
791 }
792 chan = kzalloc(sizeof(struct lttng_kernel_channel_buffer), GFP_KERNEL);
793 if (!chan)
794 goto nomem;
795 chan_priv = kzalloc(sizeof(struct lttng_kernel_channel_buffer_private), GFP_KERNEL);
796 if (!chan_priv)
797 goto nomem_priv;
798 chan->priv = chan_priv;
799 chan_priv->pub = chan;
800 chan->parent.type = LTTNG_KERNEL_CHANNEL_TYPE_BUFFER;
801 chan->parent.session = session;
802 chan->priv->id = session->priv->free_chan_id++;
803 chan->ops = &transport->ops;
804 /*
805 * Note: the channel creation op already writes into the packet
806 * headers. Therefore the "chan" information used as input
807 * should be already accessible.
808 */
809 chan->priv->rb_chan = transport->ops.priv->channel_create(transport_name,
810 chan, buf_addr, subbuf_size, num_subbuf,
811 switch_timer_interval, read_timer_interval);
812 if (!chan->priv->rb_chan)
813 goto create_error;
814 chan->priv->parent.tstate = 1;
815 chan->parent.enabled = 1;
816 chan->priv->transport = transport;
817 chan->priv->channel_type = channel_type;
818 list_add(&chan->priv->node, &session->priv->chan);
819 mutex_unlock(&sessions_mutex);
820 return chan;
821
822 create_error:
823 kfree(chan_priv);
824 nomem_priv:
825 kfree(chan);
826 nomem:
827 if (transport)
828 module_put(transport->owner);
829 notransport:
830 active:
831 mutex_unlock(&sessions_mutex);
832 return NULL;
833 }
834
835 /*
836 * Only used internally at session destruction for per-cpu channels, and
837 * when metadata channel is released.
838 * Needs to be called with sessions mutex held.
839 */
840 static
841 void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan)
842 {
843 chan->ops->priv->channel_destroy(chan->priv->rb_chan);
844 module_put(chan->priv->transport->owner);
845 list_del(&chan->priv->node);
846 lttng_kernel_destroy_context(chan->priv->ctx);
847 kfree(chan->priv);
848 kfree(chan);
849 }
850
851 void lttng_metadata_channel_destroy(struct lttng_kernel_channel_buffer *chan)
852 {
853 BUG_ON(chan->priv->channel_type != METADATA_CHANNEL);
854
855 /* Protect the metadata cache with the sessions_mutex. */
856 mutex_lock(&sessions_mutex);
857 _lttng_channel_destroy(chan);
858 mutex_unlock(&sessions_mutex);
859 }
860 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
861
862 static
863 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
864 {
865 stream->finalized = 1;
866 wake_up_interruptible(&stream->read_wait);
867 }
868
869 static
870 struct lttng_kernel_event_common *lttng_kernel_event_alloc(struct lttng_event_enabler_common *event_enabler)
871 {
872 struct lttng_kernel_abi_event *event_param = &event_enabler->event_param;
873 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
874
875 switch (event_enabler->enabler_type) {
876 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
877 {
878 struct lttng_event_recorder_enabler *event_recorder_enabler =
879 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
880 struct lttng_kernel_event_recorder *event_recorder;
881 struct lttng_kernel_event_recorder_private *event_recorder_priv;
882 struct lttng_kernel_channel_buffer *chan = event_recorder_enabler->chan;
883
884 event_recorder = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
885 if (!event_recorder)
886 return NULL;
887 event_recorder_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
888 if (!event_recorder_priv) {
889 kmem_cache_free(event_recorder_private_cache, event_recorder);
890 return NULL;
891 }
892 event_recorder_priv->pub = event_recorder;
893 event_recorder_priv->parent.pub = &event_recorder->parent;
894 event_recorder->priv = event_recorder_priv;
895 event_recorder->parent.priv = &event_recorder_priv->parent;
896
897 event_recorder->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
898 event_recorder->parent.run_filter = lttng_kernel_interpret_event_filter;
899 event_recorder->priv->parent.instrumentation = itype;
900 INIT_LIST_HEAD(&event_recorder->priv->parent.filter_bytecode_runtime_head);
901 INIT_LIST_HEAD(&event_recorder->priv->parent.enablers_ref_head);
902
903 event_recorder->chan = chan;
904 event_recorder->priv->id = chan->priv->free_event_id++;
905 return &event_recorder->parent;
906 }
907 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
908 {
909 struct lttng_event_notifier_enabler *event_notifier_enabler =
910 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
911 struct lttng_kernel_event_notifier *event_notifier;
912 struct lttng_kernel_event_notifier_private *event_notifier_priv;
913
914 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
915 if (!event_notifier)
916 return NULL;
917 event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
918 if (!event_notifier_priv) {
919 kmem_cache_free(event_notifier_private_cache, event_notifier);
920 return NULL;
921 }
922 event_notifier_priv->pub = event_notifier;
923 event_notifier_priv->parent.pub = &event_notifier->parent;
924 event_notifier->priv = event_notifier_priv;
925 event_notifier->parent.priv = &event_notifier_priv->parent;
926
927 event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
928 event_notifier->parent.run_filter = lttng_kernel_interpret_event_filter;
929 event_notifier->priv->parent.instrumentation = itype;
930 event_notifier->priv->parent.user_token = event_enabler->user_token;
931 INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
932 INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
933
934 event_notifier->priv->group = event_notifier_enabler->group;
935 event_notifier->priv->error_counter_index = event_notifier_enabler->error_counter_index;
936 event_notifier->priv->num_captures = 0;
937 event_notifier->notification_send = lttng_event_notifier_notification_send;
938 INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
939 return &event_notifier->parent;
940 }
941 default:
942 return NULL;
943 }
944 }
945
946 static
947 void lttng_kernel_event_free(struct lttng_kernel_event_common *event)
948 {
949 switch (event->type) {
950 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
951 {
952 struct lttng_kernel_event_recorder *event_recorder =
953 container_of(event, struct lttng_kernel_event_recorder, parent);
954
955 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
956 kmem_cache_free(event_recorder_cache, event_recorder);
957 break;
958 }
959 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
960 {
961 struct lttng_kernel_event_notifier *event_notifier =
962 container_of(event, struct lttng_kernel_event_notifier, parent);
963
964 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
965 kmem_cache_free(event_notifier_cache, event_notifier);
966 break;
967 }
968 default:
969 WARN_ON_ONCE(1);
970 }
971 }
972
973 static
974 int lttng_kernel_event_notifier_clear_error_counter(struct lttng_kernel_event_common *event)
975 {
976 switch (event->type) {
977 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
978 return 0;
979 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
980 {
981 struct lttng_kernel_event_notifier *event_notifier =
982 container_of(event, struct lttng_kernel_event_notifier, parent);
983 struct lttng_counter *error_counter;
984 struct lttng_event_notifier_group *event_notifier_group = event_notifier->priv->group;
985 size_t dimension_index[1];
986 int ret;
987
988 /*
989 * Clear the error counter bucket. The sessiond keeps track of which
990 * bucket is currently in use. We trust it. The session lock
991 * synchronizes against concurrent creation of the error
992 * counter.
993 */
994 error_counter = event_notifier_group->error_counter;
995 if (!error_counter)
996 return 0;
997 /*
998 * Check that the index is within the boundary of the counter.
999 */
1000 if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
1001 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1002 event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
1003 return -EINVAL;
1004 }
1005
1006 dimension_index[0] = event_notifier->priv->error_counter_index;
1007 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1008 if (ret) {
1009 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1010 event_notifier->priv->error_counter_index);
1011 return -EINVAL;
1012 }
1013 return 0;
1014 }
1015 default:
1016 return -EINVAL;
1017 }
1018 }
1019
1020 /*
1021 * Supports event creation while tracing session is active.
1022 * Needs to be called with sessions mutex held.
1023 */
1024 static
1025 struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_event_recorder_enabler *event_enabler,
1026 const struct lttng_kernel_event_desc *event_desc)
1027 {
1028 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_enabler->parent);
1029 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(&event_enabler->parent);
1030 struct lttng_kernel_channel_buffer *chan = event_enabler->chan;
1031 struct lttng_kernel_abi_event *event_param = &event_enabler->parent.event_param;
1032 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
1033 struct lttng_kernel_event_common_private *event_priv;
1034 struct lttng_kernel_event_common *event;
1035 struct lttng_kernel_event_recorder *event_recorder;
1036 const char *event_name;
1037 struct hlist_head *head;
1038 int ret;
1039
1040 if (chan->priv->free_event_id == -1U) {
1041 ret = -EMFILE;
1042 goto full;
1043 }
1044
1045 switch (itype) {
1046 case LTTNG_KERNEL_ABI_TRACEPOINT:
1047 event_name = event_desc->event_name;
1048 break;
1049
1050 case LTTNG_KERNEL_ABI_KPROBE:
1051 lttng_fallthrough;
1052 case LTTNG_KERNEL_ABI_UPROBE:
1053 lttng_fallthrough;
1054 case LTTNG_KERNEL_ABI_KRETPROBE:
1055 lttng_fallthrough;
1056 case LTTNG_KERNEL_ABI_SYSCALL:
1057 event_name = event_param->name;
1058 break;
1059
1060 case LTTNG_KERNEL_ABI_FUNCTION:
1061 lttng_fallthrough;
1062 case LTTNG_KERNEL_ABI_NOOP:
1063 lttng_fallthrough;
1064 default:
1065 WARN_ON_ONCE(1);
1066 ret = -EINVAL;
1067 goto type_error;
1068 }
1069
1070 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, event_name);
1071 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
1072 if (lttng_event_enabler_event_name_match_event(&event_enabler->parent, event_name, event_priv->pub)) {
1073 ret = -EEXIST;
1074 goto exist;
1075 }
1076 }
1077
1078 event = lttng_kernel_event_alloc(&event_enabler->parent);
1079 if (!event) {
1080 ret = -ENOMEM;
1081 goto alloc_error;
1082 }
1083 event_recorder = container_of(event, struct lttng_kernel_event_recorder, parent);
1084
1085 switch (itype) {
1086 case LTTNG_KERNEL_ABI_TRACEPOINT:
1087 /* Event will be enabled by enabler sync. */
1088 event->enabled = 0;
1089 event->priv->registered = 0;
1090 event->priv->desc = lttng_event_desc_get(event_name);
1091 if (!event->priv->desc) {
1092 ret = -ENOENT;
1093 goto register_error;
1094 }
1095 /* Populate lttng_event structure before event registration. */
1096 smp_wmb();
1097 break;
1098
1099 case LTTNG_KERNEL_ABI_KPROBE:
1100 /*
1101 * Needs to be explicitly enabled after creation, since
1102 * we may want to apply filters.
1103 */
1104 event->enabled = 0;
1105 event->priv->registered = 1;
1106 /*
1107 * Populate lttng_event structure before event
1108 * registration.
1109 */
1110 smp_wmb();
1111 ret = lttng_kprobes_register_event(event_name,
1112 event_param->u.kprobe.symbol_name,
1113 event_param->u.kprobe.offset,
1114 event_param->u.kprobe.addr,
1115 event);
1116 if (ret) {
1117 ret = -EINVAL;
1118 goto register_error;
1119 }
1120 ret = try_module_get(event->priv->desc->owner);
1121 WARN_ON_ONCE(!ret);
1122 break;
1123
1124 case LTTNG_KERNEL_ABI_KRETPROBE:
1125 {
1126 struct lttng_kernel_event_common *event_return;
1127 struct lttng_kernel_event_recorder *event_recorder_return;
1128
1129 /* kretprobe defines 2 events */
1130 /*
1131 * Needs to be explicitly enabled after creation, since
1132 * we may want to apply filters.
1133 */
1134 event->enabled = 0;
1135 event->priv->registered = 1;
1136
1137 event_return = lttng_kernel_event_alloc(&event_enabler->parent);
1138 if (!event) {
1139 ret = -ENOMEM;
1140 goto alloc_error;
1141 }
1142 event_recorder_return = container_of(event_return, struct lttng_kernel_event_recorder, parent);
1143
1144 event_return->enabled = 0;
1145 event_return->priv->registered = 1;
1146
1147 /*
1148 * Populate lttng_event structure before kretprobe registration.
1149 */
1150 smp_wmb();
1151 ret = lttng_kretprobes_register(event_name,
1152 event_param->u.kretprobe.symbol_name,
1153 event_param->u.kretprobe.offset,
1154 event_param->u.kretprobe.addr,
1155 event, event_return);
1156 if (ret) {
1157 lttng_kernel_event_free(event_return);
1158 ret = -EINVAL;
1159 goto register_error;
1160 }
1161 /* Take 2 refs on the module: one per event. */
1162 ret = try_module_get(event->priv->desc->owner);
1163 WARN_ON_ONCE(!ret);
1164 ret = try_module_get(event_return->priv->desc->owner);
1165 WARN_ON_ONCE(!ret);
1166 ret = _lttng_event_metadata_statedump(chan->parent.session, chan, event_recorder_return);
1167 WARN_ON_ONCE(ret > 0);
1168 if (ret) {
1169 lttng_kernel_event_free(event_return);
1170 module_put(event_return->priv->desc->owner);
1171 module_put(event->priv->desc->owner);
1172 goto statedump_error;
1173 }
1174 list_add(&event_return->priv->node, event_list_head);
1175 break;
1176 }
1177
1178 case LTTNG_KERNEL_ABI_SYSCALL:
1179 /*
1180 * Needs to be explicitly enabled after creation, since
1181 * we may want to apply filters.
1182 */
1183 event->enabled = 0;
1184 event->priv->registered = 0;
1185 event->priv->desc = event_desc;
1186 switch (event_param->u.syscall.entryexit) {
1187 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1188 ret = -EINVAL;
1189 goto register_error;
1190 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1191 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1192 break;
1193 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1194 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1195 break;
1196 }
1197 switch (event_param->u.syscall.abi) {
1198 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1199 ret = -EINVAL;
1200 goto register_error;
1201 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1202 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1203 break;
1204 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1205 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1206 break;
1207 }
1208 if (!event->priv->desc) {
1209 ret = -EINVAL;
1210 goto register_error;
1211 }
1212 break;
1213
1214 case LTTNG_KERNEL_ABI_UPROBE:
1215 /*
1216 * Needs to be explicitly enabled after creation, since
1217 * we may want to apply filters.
1218 */
1219 event->enabled = 0;
1220 event->priv->registered = 1;
1221
1222 /*
1223 * Populate lttng_event structure before event
1224 * registration.
1225 */
1226 smp_wmb();
1227
1228 ret = lttng_uprobes_register_event(event_param->name,
1229 event_param->u.uprobe.fd,
1230 event);
1231 if (ret)
1232 goto register_error;
1233 ret = try_module_get(event->priv->desc->owner);
1234 WARN_ON_ONCE(!ret);
1235 break;
1236
1237 case LTTNG_KERNEL_ABI_FUNCTION:
1238 lttng_fallthrough;
1239 case LTTNG_KERNEL_ABI_NOOP:
1240 lttng_fallthrough;
1241 default:
1242 WARN_ON_ONCE(1);
1243 ret = -EINVAL;
1244 goto register_error;
1245 }
1246 ret = _lttng_event_metadata_statedump(chan->parent.session, chan, event_recorder);
1247 WARN_ON_ONCE(ret > 0);
1248 if (ret) {
1249 goto statedump_error;
1250 }
1251 hlist_add_head(&event->priv->hlist_node, head);
1252 list_add(&event->priv->node, event_list_head);
1253 return event_recorder;
1254
1255 statedump_error:
1256 /* If a statedump error occurs, events will not be readable. */
1257 register_error:
1258 lttng_kernel_event_free(event);
1259 alloc_error:
1260 exist:
1261 type_error:
1262 full:
1263 return ERR_PTR(ret);
1264 }
1265
1266 static
1267 struct lttng_kernel_event_notifier *_lttng_kernel_event_notifier_create(struct lttng_event_notifier_enabler *event_enabler,
1268 const struct lttng_kernel_event_desc *event_desc)
1269 {
1270 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_enabler->parent);
1271 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(&event_enabler->parent);
1272 struct lttng_kernel_abi_event *event_param = &event_enabler->parent.event_param;
1273 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
1274 struct lttng_kernel_event_common_private *event_priv;
1275 struct lttng_kernel_event_common *event;
1276 struct lttng_kernel_event_notifier *event_notifier;
1277 const char *event_name;
1278 struct hlist_head *head;
1279 int ret;
1280
1281 switch (itype) {
1282 case LTTNG_KERNEL_ABI_TRACEPOINT:
1283 event_name = event_desc->event_name;
1284 break;
1285
1286 case LTTNG_KERNEL_ABI_KPROBE:
1287 lttng_fallthrough;
1288 case LTTNG_KERNEL_ABI_UPROBE:
1289 lttng_fallthrough;
1290 case LTTNG_KERNEL_ABI_SYSCALL:
1291 event_name = event_param->name;
1292 break;
1293
1294 case LTTNG_KERNEL_ABI_KRETPROBE:
1295 lttng_fallthrough;
1296 case LTTNG_KERNEL_ABI_FUNCTION:
1297 lttng_fallthrough;
1298 case LTTNG_KERNEL_ABI_NOOP:
1299 lttng_fallthrough;
1300 default:
1301 WARN_ON_ONCE(1);
1302 ret = -EINVAL;
1303 goto type_error;
1304 }
1305
1306 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, event_name);
1307 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
1308 if (lttng_event_enabler_event_name_match_event(&event_enabler->parent, event_name, event_priv->pub)) {
1309 ret = -EEXIST;
1310 goto exist;
1311 }
1312 }
1313
1314 event = lttng_kernel_event_alloc(&event_enabler->parent);
1315 if (!event) {
1316 ret = -ENOMEM;
1317 goto alloc_error;
1318 }
1319 event_notifier = container_of(event, struct lttng_kernel_event_notifier, parent);
1320
1321 switch (itype) {
1322 case LTTNG_KERNEL_ABI_TRACEPOINT:
1323 /* Event will be enabled by enabler sync. */
1324 event->enabled = 0;
1325 event->priv->registered = 0;
1326 event->priv->desc = lttng_event_desc_get(event_name);
1327 if (!event->priv->desc) {
1328 ret = -ENOENT;
1329 goto register_error;
1330 }
1331 /* Populate lttng_event_notifier structure before event registration. */
1332 smp_wmb();
1333 break;
1334
1335 case LTTNG_KERNEL_ABI_KPROBE:
1336 /*
1337 * Needs to be explicitly enabled after creation, since
1338 * we may want to apply filters.
1339 */
1340 event->enabled = 0;
1341 event->priv->registered = 1;
1342 /*
1343 * Populate lttng_event_notifier structure before event
1344 * registration.
1345 */
1346 smp_wmb();
1347 ret = lttng_kprobes_register_event(event_param->u.kprobe.symbol_name,
1348 event_param->u.kprobe.symbol_name,
1349 event_param->u.kprobe.offset,
1350 event_param->u.kprobe.addr,
1351 event);
1352 if (ret) {
1353 ret = -EINVAL;
1354 goto register_error;
1355 }
1356 ret = try_module_get(event->priv->desc->owner);
1357 WARN_ON_ONCE(!ret);
1358 break;
1359
1360 case LTTNG_KERNEL_ABI_SYSCALL:
1361 /*
1362 * Needs to be explicitly enabled after creation, since
1363 * we may want to apply filters.
1364 */
1365 event->enabled = 0;
1366 event->priv->registered = 0;
1367 event->priv->desc = event_desc;
1368 switch (event_param->u.syscall.entryexit) {
1369 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1370 ret = -EINVAL;
1371 goto register_error;
1372 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1373 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1374 break;
1375 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1376 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1377 break;
1378 }
1379 switch (event_param->u.syscall.abi) {
1380 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1381 ret = -EINVAL;
1382 goto register_error;
1383 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1384 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1385 break;
1386 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1387 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1388 break;
1389 }
1390
1391 if (!event->priv->desc) {
1392 ret = -EINVAL;
1393 goto register_error;
1394 }
1395 break;
1396
1397 case LTTNG_KERNEL_ABI_UPROBE:
1398 /*
1399 * Needs to be explicitly enabled after creation, since
1400 * we may want to apply filters.
1401 */
1402 event->enabled = 0;
1403 event->priv->registered = 1;
1404
1405 /*
1406 * Populate lttng_event_notifier structure before
1407 * event_notifier registration.
1408 */
1409 smp_wmb();
1410
1411 ret = lttng_uprobes_register_event(event_param->name,
1412 event_param->u.uprobe.fd,
1413 event);
1414 if (ret)
1415 goto register_error;
1416 ret = try_module_get(event->priv->desc->owner);
1417 WARN_ON_ONCE(!ret);
1418 break;
1419
1420 case LTTNG_KERNEL_ABI_KRETPROBE:
1421 lttng_fallthrough;
1422 case LTTNG_KERNEL_ABI_FUNCTION:
1423 lttng_fallthrough;
1424 case LTTNG_KERNEL_ABI_NOOP:
1425 lttng_fallthrough;
1426 default:
1427 WARN_ON_ONCE(1);
1428 ret = -EINVAL;
1429 goto register_error;
1430 }
1431
1432 list_add(&event->priv->node, event_list_head);
1433 hlist_add_head(&event->priv->hlist_node, head);
1434
1435 ret = lttng_kernel_event_notifier_clear_error_counter(event);
1436 if (ret)
1437 goto register_error;
1438 return event_notifier;
1439
1440 register_error:
1441 lttng_kernel_event_free(event);
1442 alloc_error:
1443 exist:
1444 type_error:
1445 return ERR_PTR(ret);
1446 }
1447
1448 struct lttng_kernel_event_common *_lttng_kernel_event_create(struct lttng_event_enabler_common *event_enabler,
1449 const struct lttng_kernel_event_desc *event_desc)
1450 {
1451 switch (event_enabler->enabler_type) {
1452 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
1453 {
1454 struct lttng_event_recorder_enabler *event_recorder_enabler =
1455 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
1456 struct lttng_kernel_event_recorder *event_recorder;
1457
1458 event_recorder = _lttng_kernel_event_recorder_create(event_recorder_enabler, event_desc);
1459 if (!event_recorder)
1460 return NULL;
1461 return &event_recorder->parent;
1462 }
1463 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
1464 {
1465 struct lttng_event_notifier_enabler *event_notifier_enabler =
1466 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
1467 struct lttng_kernel_event_notifier *event_notifier;
1468
1469 event_notifier = _lttng_kernel_event_notifier_create(event_notifier_enabler, event_desc);
1470 if (!event_notifier)
1471 return NULL;
1472 return &event_notifier->parent;
1473 }
1474 default:
1475 return NULL;
1476 }
1477 }
1478
1479 struct lttng_kernel_event_common *lttng_kernel_event_create(struct lttng_event_enabler_common *event_enabler,
1480 const struct lttng_kernel_event_desc *event_desc)
1481 {
1482 struct lttng_kernel_event_common *event;
1483
1484 mutex_lock(&sessions_mutex);
1485 event = _lttng_kernel_event_create(event_enabler, event_desc);
1486 mutex_unlock(&sessions_mutex);
1487 return event;
1488 }
1489
1490
1491
1492 int lttng_kernel_counter_read(struct lttng_counter *counter,
1493 const size_t *dim_indexes, int32_t cpu,
1494 int64_t *val, bool *overflow, bool *underflow)
1495 {
1496 return counter->ops->counter_read(counter->counter, dim_indexes,
1497 cpu, val, overflow, underflow);
1498 }
1499
1500 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1501 const size_t *dim_indexes, int64_t *val,
1502 bool *overflow, bool *underflow)
1503 {
1504 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1505 val, overflow, underflow);
1506 }
1507
1508 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1509 const size_t *dim_indexes)
1510 {
1511 return counter->ops->counter_clear(counter->counter, dim_indexes);
1512 }
1513
1514 /* Only used for tracepoints for now. */
1515 static
1516 void register_event(struct lttng_kernel_event_common *event)
1517 {
1518 const struct lttng_kernel_event_desc *desc;
1519 int ret = -EINVAL;
1520
1521 if (event->priv->registered)
1522 return;
1523
1524 desc = event->priv->desc;
1525 switch (event->priv->instrumentation) {
1526 case LTTNG_KERNEL_ABI_TRACEPOINT:
1527 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1528 desc->tp_class->probe_callback,
1529 event);
1530 break;
1531
1532 case LTTNG_KERNEL_ABI_SYSCALL:
1533 ret = lttng_syscall_filter_enable_event(event);
1534 break;
1535
1536 case LTTNG_KERNEL_ABI_KPROBE:
1537 lttng_fallthrough;
1538 case LTTNG_KERNEL_ABI_UPROBE:
1539 ret = 0;
1540 break;
1541
1542 case LTTNG_KERNEL_ABI_KRETPROBE:
1543 switch (event->type) {
1544 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1545 ret = 0;
1546 break;
1547 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1548 WARN_ON_ONCE(1);
1549 break;
1550 }
1551 break;
1552
1553 case LTTNG_KERNEL_ABI_FUNCTION:
1554 lttng_fallthrough;
1555 case LTTNG_KERNEL_ABI_NOOP:
1556 lttng_fallthrough;
1557 default:
1558 WARN_ON_ONCE(1);
1559 }
1560 if (!ret)
1561 event->priv->registered = 1;
1562 }
1563
1564 int _lttng_event_unregister(struct lttng_kernel_event_common *event)
1565 {
1566 struct lttng_kernel_event_common_private *event_priv = event->priv;
1567 const struct lttng_kernel_event_desc *desc;
1568 int ret = -EINVAL;
1569
1570 if (!event_priv->registered)
1571 return 0;
1572
1573 desc = event_priv->desc;
1574 switch (event_priv->instrumentation) {
1575 case LTTNG_KERNEL_ABI_TRACEPOINT:
1576 ret = lttng_wrapper_tracepoint_probe_unregister(event_priv->desc->event_kname,
1577 event_priv->desc->tp_class->probe_callback,
1578 event);
1579 break;
1580
1581 case LTTNG_KERNEL_ABI_KPROBE:
1582 lttng_kprobes_unregister_event(event);
1583 ret = 0;
1584 break;
1585
1586 case LTTNG_KERNEL_ABI_KRETPROBE:
1587 switch (event->type) {
1588 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1589 lttng_kretprobes_unregister(event);
1590 ret = 0;
1591 break;
1592 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1593 WARN_ON_ONCE(1);
1594 break;
1595 }
1596 break;
1597
1598 case LTTNG_KERNEL_ABI_SYSCALL:
1599 ret = lttng_syscall_filter_disable_event(event);
1600 break;
1601
1602 case LTTNG_KERNEL_ABI_NOOP:
1603 switch (event->type) {
1604 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1605 ret = 0;
1606 break;
1607 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1608 WARN_ON_ONCE(1);
1609 break;
1610 }
1611 break;
1612
1613 case LTTNG_KERNEL_ABI_UPROBE:
1614 lttng_uprobes_unregister_event(event);
1615 ret = 0;
1616 break;
1617
1618 case LTTNG_KERNEL_ABI_FUNCTION:
1619 lttng_fallthrough;
1620 default:
1621 WARN_ON_ONCE(1);
1622 }
1623 if (!ret)
1624 event_priv->registered = 0;
1625 return ret;
1626 }
1627
1628 /*
1629 * Only used internally at session destruction.
1630 */
1631 static
1632 void _lttng_event_destroy(struct lttng_kernel_event_common *event)
1633 {
1634 struct lttng_kernel_event_common_private *event_priv = event->priv;
1635 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1636
1637 lttng_free_event_filter_runtime(event);
1638 /* Free event enabler refs */
1639 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1640 &event_priv->enablers_ref_head, node)
1641 kfree(enabler_ref);
1642
1643 switch (event->type) {
1644 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1645 {
1646 struct lttng_kernel_event_recorder *event_recorder =
1647 container_of(event, struct lttng_kernel_event_recorder, parent);
1648
1649 switch (event_priv->instrumentation) {
1650 case LTTNG_KERNEL_ABI_TRACEPOINT:
1651 lttng_event_desc_put(event_priv->desc);
1652 break;
1653
1654 case LTTNG_KERNEL_ABI_KPROBE:
1655 module_put(event_priv->desc->owner);
1656 lttng_kprobes_destroy_event_private(&event_recorder->parent);
1657 break;
1658
1659 case LTTNG_KERNEL_ABI_KRETPROBE:
1660 module_put(event_priv->desc->owner);
1661 lttng_kretprobes_destroy_private(&event_recorder->parent);
1662 break;
1663
1664 case LTTNG_KERNEL_ABI_SYSCALL:
1665 break;
1666
1667 case LTTNG_KERNEL_ABI_UPROBE:
1668 module_put(event_priv->desc->owner);
1669 lttng_uprobes_destroy_event_private(&event_recorder->parent);
1670 break;
1671
1672 case LTTNG_KERNEL_ABI_FUNCTION:
1673 lttng_fallthrough;
1674 case LTTNG_KERNEL_ABI_NOOP:
1675 lttng_fallthrough;
1676 default:
1677 WARN_ON_ONCE(1);
1678 }
1679 list_del(&event_recorder->priv->parent.node);
1680 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
1681 kmem_cache_free(event_recorder_cache, event_recorder);
1682 break;
1683 }
1684 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1685 {
1686 struct lttng_kernel_event_notifier *event_notifier =
1687 container_of(event, struct lttng_kernel_event_notifier, parent);
1688
1689 switch (event_notifier->priv->parent.instrumentation) {
1690 case LTTNG_KERNEL_ABI_TRACEPOINT:
1691 lttng_event_desc_put(event_notifier->priv->parent.desc);
1692 break;
1693
1694 case LTTNG_KERNEL_ABI_KPROBE:
1695 module_put(event_notifier->priv->parent.desc->owner);
1696 lttng_kprobes_destroy_event_private(&event_notifier->parent);
1697 break;
1698
1699 case LTTNG_KERNEL_ABI_SYSCALL:
1700 break;
1701
1702 case LTTNG_KERNEL_ABI_UPROBE:
1703 module_put(event_notifier->priv->parent.desc->owner);
1704 lttng_uprobes_destroy_event_private(&event_notifier->parent);
1705 break;
1706
1707 case LTTNG_KERNEL_ABI_KRETPROBE:
1708 lttng_fallthrough;
1709 case LTTNG_KERNEL_ABI_FUNCTION:
1710 lttng_fallthrough;
1711 case LTTNG_KERNEL_ABI_NOOP:
1712 lttng_fallthrough;
1713 default:
1714 WARN_ON_ONCE(1);
1715 }
1716 list_del(&event_notifier->priv->parent.node);
1717 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1718 kmem_cache_free(event_notifier_cache, event_notifier);
1719 break;
1720 }
1721 default:
1722 WARN_ON_ONCE(1);
1723 }
1724 }
1725
1726 struct lttng_kernel_id_tracker *get_tracker(struct lttng_kernel_session *session,
1727 enum tracker_type tracker_type)
1728 {
1729 switch (tracker_type) {
1730 case TRACKER_PID:
1731 return &session->pid_tracker;
1732 case TRACKER_VPID:
1733 return &session->vpid_tracker;
1734 case TRACKER_UID:
1735 return &session->uid_tracker;
1736 case TRACKER_VUID:
1737 return &session->vuid_tracker;
1738 case TRACKER_GID:
1739 return &session->gid_tracker;
1740 case TRACKER_VGID:
1741 return &session->vgid_tracker;
1742 default:
1743 WARN_ON_ONCE(1);
1744 return NULL;
1745 }
1746 }
1747
1748 int lttng_session_track_id(struct lttng_kernel_session *session,
1749 enum tracker_type tracker_type, int id)
1750 {
1751 struct lttng_kernel_id_tracker *tracker;
1752 int ret;
1753
1754 tracker = get_tracker(session, tracker_type);
1755 if (!tracker)
1756 return -EINVAL;
1757 if (id < -1)
1758 return -EINVAL;
1759 mutex_lock(&sessions_mutex);
1760 if (id == -1) {
1761 /* track all ids: destroy tracker. */
1762 lttng_id_tracker_destroy(tracker, true);
1763 ret = 0;
1764 } else {
1765 ret = lttng_id_tracker_add(tracker, id);
1766 }
1767 mutex_unlock(&sessions_mutex);
1768 return ret;
1769 }
1770
1771 int lttng_session_untrack_id(struct lttng_kernel_session *session,
1772 enum tracker_type tracker_type, int id)
1773 {
1774 struct lttng_kernel_id_tracker *tracker;
1775 int ret;
1776
1777 tracker = get_tracker(session, tracker_type);
1778 if (!tracker)
1779 return -EINVAL;
1780 if (id < -1)
1781 return -EINVAL;
1782 mutex_lock(&sessions_mutex);
1783 if (id == -1) {
1784 /* untrack all ids: replace by empty tracker. */
1785 ret = lttng_id_tracker_empty_set(tracker);
1786 } else {
1787 ret = lttng_id_tracker_del(tracker, id);
1788 }
1789 mutex_unlock(&sessions_mutex);
1790 return ret;
1791 }
1792
1793 static
1794 void *id_list_start(struct seq_file *m, loff_t *pos)
1795 {
1796 struct lttng_kernel_id_tracker *id_tracker = m->private;
1797 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1798 struct lttng_id_hash_node *e;
1799 int iter = 0, i;
1800
1801 mutex_lock(&sessions_mutex);
1802 if (id_tracker_p) {
1803 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1804 struct hlist_head *head = &id_tracker_p->id_hash[i];
1805
1806 lttng_hlist_for_each_entry(e, head, hlist) {
1807 if (iter++ >= *pos)
1808 return e;
1809 }
1810 }
1811 } else {
1812 /* ID tracker disabled. */
1813 if (iter >= *pos && iter == 0) {
1814 return id_tracker_p; /* empty tracker */
1815 }
1816 iter++;
1817 }
1818 /* End of list */
1819 return NULL;
1820 }
1821
1822 /* Called with sessions_mutex held. */
1823 static
1824 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1825 {
1826 struct lttng_kernel_id_tracker *id_tracker = m->private;
1827 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1828 struct lttng_id_hash_node *e;
1829 int iter = 0, i;
1830
1831 (*ppos)++;
1832 if (id_tracker_p) {
1833 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1834 struct hlist_head *head = &id_tracker_p->id_hash[i];
1835
1836 lttng_hlist_for_each_entry(e, head, hlist) {
1837 if (iter++ >= *ppos)
1838 return e;
1839 }
1840 }
1841 } else {
1842 /* ID tracker disabled. */
1843 if (iter >= *ppos && iter == 0)
1844 return p; /* empty tracker */
1845 iter++;
1846 }
1847
1848 /* End of list */
1849 return NULL;
1850 }
1851
1852 static
1853 void id_list_stop(struct seq_file *m, void *p)
1854 {
1855 mutex_unlock(&sessions_mutex);
1856 }
1857
1858 static
1859 int id_list_show(struct seq_file *m, void *p)
1860 {
1861 struct lttng_kernel_id_tracker *id_tracker = m->private;
1862 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1863 int id;
1864
1865 if (p == id_tracker_p) {
1866 /* Tracker disabled. */
1867 id = -1;
1868 } else {
1869 const struct lttng_id_hash_node *e = p;
1870
1871 id = lttng_id_tracker_get_node_id(e);
1872 }
1873 switch (id_tracker->priv->tracker_type) {
1874 case TRACKER_PID:
1875 seq_printf(m, "process { pid = %d; };\n", id);
1876 break;
1877 case TRACKER_VPID:
1878 seq_printf(m, "process { vpid = %d; };\n", id);
1879 break;
1880 case TRACKER_UID:
1881 seq_printf(m, "user { uid = %d; };\n", id);
1882 break;
1883 case TRACKER_VUID:
1884 seq_printf(m, "user { vuid = %d; };\n", id);
1885 break;
1886 case TRACKER_GID:
1887 seq_printf(m, "group { gid = %d; };\n", id);
1888 break;
1889 case TRACKER_VGID:
1890 seq_printf(m, "group { vgid = %d; };\n", id);
1891 break;
1892 default:
1893 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1894 }
1895 return 0;
1896 }
1897
1898 static
1899 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1900 .start = id_list_start,
1901 .next = id_list_next,
1902 .stop = id_list_stop,
1903 .show = id_list_show,
1904 };
1905
1906 static
1907 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1908 {
1909 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1910 }
1911
1912 static
1913 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1914 {
1915 struct seq_file *m = file->private_data;
1916 struct lttng_kernel_id_tracker *id_tracker = m->private;
1917 int ret;
1918
1919 WARN_ON_ONCE(!id_tracker);
1920 ret = seq_release(inode, file);
1921 if (!ret)
1922 fput(id_tracker->priv->session->priv->file);
1923 return ret;
1924 }
1925
1926 const struct file_operations lttng_tracker_ids_list_fops = {
1927 .owner = THIS_MODULE,
1928 .open = lttng_tracker_ids_list_open,
1929 .read = seq_read,
1930 .llseek = seq_lseek,
1931 .release = lttng_tracker_ids_list_release,
1932 };
1933
1934 int lttng_session_list_tracker_ids(struct lttng_kernel_session *session,
1935 enum tracker_type tracker_type)
1936 {
1937 struct file *tracker_ids_list_file;
1938 struct seq_file *m;
1939 int file_fd, ret;
1940
1941 file_fd = lttng_get_unused_fd();
1942 if (file_fd < 0) {
1943 ret = file_fd;
1944 goto fd_error;
1945 }
1946
1947 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1948 &lttng_tracker_ids_list_fops,
1949 NULL, O_RDWR);
1950 if (IS_ERR(tracker_ids_list_file)) {
1951 ret = PTR_ERR(tracker_ids_list_file);
1952 goto file_error;
1953 }
1954 if (!atomic_long_add_unless(&session->priv->file->f_count, 1, LONG_MAX)) {
1955 ret = -EOVERFLOW;
1956 goto refcount_error;
1957 }
1958 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1959 if (ret < 0)
1960 goto open_error;
1961 m = tracker_ids_list_file->private_data;
1962
1963 m->private = get_tracker(session, tracker_type);
1964 BUG_ON(!m->private);
1965 fd_install(file_fd, tracker_ids_list_file);
1966
1967 return file_fd;
1968
1969 open_error:
1970 atomic_long_dec(&session->priv->file->f_count);
1971 refcount_error:
1972 fput(tracker_ids_list_file);
1973 file_error:
1974 put_unused_fd(file_fd);
1975 fd_error:
1976 return ret;
1977 }
1978
1979 /*
1980 * Enabler management.
1981 */
1982 static
1983 int lttng_match_enabler_star_glob(const char *desc_name,
1984 const char *pattern)
1985 {
1986 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1987 desc_name, LTTNG_SIZE_MAX))
1988 return 0;
1989 return 1;
1990 }
1991
1992 static
1993 int lttng_match_enabler_name(const char *desc_name,
1994 const char *name)
1995 {
1996 if (strcmp(desc_name, name))
1997 return 0;
1998 return 1;
1999 }
2000
2001 static
2002 int lttng_desc_match_enabler_check(const struct lttng_kernel_event_desc *desc,
2003 struct lttng_event_enabler_common *enabler)
2004 {
2005 const char *desc_name, *enabler_name;
2006 bool compat = false, entry = false;
2007
2008 enabler_name = enabler->event_param.name;
2009 switch (enabler->event_param.instrumentation) {
2010 case LTTNG_KERNEL_ABI_TRACEPOINT:
2011 desc_name = desc->event_name;
2012 switch (enabler->format_type) {
2013 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2014 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2015 case LTTNG_ENABLER_FORMAT_NAME:
2016 return lttng_match_enabler_name(desc_name, enabler_name);
2017 default:
2018 return -EINVAL;
2019 }
2020 break;
2021
2022 case LTTNG_KERNEL_ABI_SYSCALL:
2023 desc_name = desc->event_name;
2024 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
2025 desc_name += strlen("compat_");
2026 compat = true;
2027 }
2028 if (!strncmp(desc_name, "syscall_exit_",
2029 strlen("syscall_exit_"))) {
2030 desc_name += strlen("syscall_exit_");
2031 } else if (!strncmp(desc_name, "syscall_entry_",
2032 strlen("syscall_entry_"))) {
2033 desc_name += strlen("syscall_entry_");
2034 entry = true;
2035 } else {
2036 WARN_ON_ONCE(1);
2037 return -EINVAL;
2038 }
2039 switch (enabler->event_param.u.syscall.entryexit) {
2040 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
2041 break;
2042 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
2043 if (!entry)
2044 return 0;
2045 break;
2046 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
2047 if (entry)
2048 return 0;
2049 break;
2050 default:
2051 return -EINVAL;
2052 }
2053 switch (enabler->event_param.u.syscall.abi) {
2054 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
2055 break;
2056 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
2057 if (compat)
2058 return 0;
2059 break;
2060 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
2061 if (!compat)
2062 return 0;
2063 break;
2064 default:
2065 return -EINVAL;
2066 }
2067 switch (enabler->event_param.u.syscall.match) {
2068 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
2069 switch (enabler->format_type) {
2070 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2071 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2072 case LTTNG_ENABLER_FORMAT_NAME:
2073 return lttng_match_enabler_name(desc_name, enabler_name);
2074 default:
2075 return -EINVAL;
2076 }
2077 break;
2078 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
2079 return -EINVAL; /* Not implemented. */
2080 default:
2081 return -EINVAL;
2082 }
2083 break;
2084
2085 default:
2086 WARN_ON_ONCE(1);
2087 return -EINVAL;
2088 }
2089 }
2090
2091 bool lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
2092 struct lttng_event_enabler_common *enabler)
2093 {
2094 int ret;
2095
2096 ret = lttng_desc_match_enabler_check(desc, enabler);
2097 if (ret < 0) {
2098 WARN_ON_ONCE(1);
2099 return false;
2100 }
2101 return ret;
2102 }
2103
2104 bool lttng_event_enabler_match_event(struct lttng_event_enabler_common *event_enabler,
2105 struct lttng_kernel_event_common *event)
2106 {
2107 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2108 return false;
2109
2110 switch (event_enabler->enabler_type) {
2111 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2112 {
2113 struct lttng_event_recorder_enabler *event_recorder_enabler =
2114 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2115 struct lttng_kernel_event_recorder *event_recorder =
2116 container_of(event, struct lttng_kernel_event_recorder, parent);
2117
2118 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
2119 && event_recorder->chan == event_recorder_enabler->chan)
2120 return true;
2121 else
2122 return false;
2123 }
2124 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2125 {
2126 struct lttng_event_notifier_enabler *event_notifier_enabler =
2127 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2128 struct lttng_kernel_event_notifier *event_notifier =
2129 container_of(event, struct lttng_kernel_event_notifier, parent);
2130
2131 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
2132 && event_notifier->priv->group == event_notifier_enabler->group
2133 && event->priv->user_token == event_enabler->user_token)
2134 return true;
2135 else
2136 return false;
2137 }
2138 default:
2139 WARN_ON_ONCE(1);
2140 return false;
2141 }
2142 }
2143
2144 bool lttng_event_enabler_desc_match_event(struct lttng_event_enabler_common *event_enabler,
2145 const struct lttng_kernel_event_desc *desc,
2146 struct lttng_kernel_event_common *event)
2147 {
2148 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2149 return false;
2150
2151 switch (event_enabler->enabler_type) {
2152 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2153 {
2154 struct lttng_event_recorder_enabler *event_recorder_enabler =
2155 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2156 struct lttng_kernel_event_recorder *event_recorder =
2157 container_of(event, struct lttng_kernel_event_recorder, parent);
2158
2159 if (event->priv->desc == desc && event_recorder->chan == event_recorder_enabler->chan)
2160 return true;
2161 else
2162 return false;
2163 }
2164 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2165 {
2166 struct lttng_event_notifier_enabler *event_notifier_enabler =
2167 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2168 struct lttng_kernel_event_notifier *event_notifier =
2169 container_of(event, struct lttng_kernel_event_notifier, parent);
2170
2171 if (event->priv->desc == desc
2172 && event_notifier->priv->group == event_notifier_enabler->group
2173 && event->priv->user_token == event_enabler->user_token)
2174 return true;
2175 else
2176 return false;
2177 }
2178 default:
2179 WARN_ON_ONCE(1);
2180 return false;
2181 }
2182 }
2183
2184 bool lttng_event_enabler_event_name_match_event(struct lttng_event_enabler_common *event_enabler,
2185 const char *event_name,
2186 struct lttng_kernel_event_common *event)
2187 {
2188 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2189 return false;
2190
2191 switch (event_enabler->enabler_type) {
2192 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2193 {
2194 struct lttng_event_recorder_enabler *event_recorder_enabler =
2195 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2196 struct lttng_kernel_event_recorder *event_recorder =
2197 container_of(event, struct lttng_kernel_event_recorder, parent);
2198
2199 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2200 && event_recorder->chan == event_recorder_enabler->chan)
2201 return true;
2202 else
2203 return false;
2204 }
2205 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2206 {
2207 struct lttng_event_notifier_enabler *event_notifier_enabler =
2208 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2209 struct lttng_kernel_event_notifier *event_notifier =
2210 container_of(event, struct lttng_kernel_event_notifier, parent);
2211
2212 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2213 && event_notifier->priv->group == event_notifier_enabler->group
2214 && event->priv->user_token == event_enabler->user_token)
2215 return true;
2216 else
2217 return false;
2218 }
2219 default:
2220 WARN_ON_ONCE(1);
2221 return false;
2222 }
2223 }
2224
2225 static
2226 struct lttng_enabler_ref *lttng_enabler_ref(
2227 struct list_head *enablers_ref_list,
2228 struct lttng_event_enabler_common *enabler)
2229 {
2230 struct lttng_enabler_ref *enabler_ref;
2231
2232 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2233 if (enabler_ref->ref == enabler)
2234 return enabler_ref;
2235 }
2236 return NULL;
2237 }
2238
2239 static
2240 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler_common *event_enabler)
2241 {
2242 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(event_enabler);
2243 struct lttng_kernel_probe_desc *probe_desc;
2244 const struct lttng_kernel_event_desc *desc;
2245 struct list_head *probe_list;
2246 int i;
2247
2248 probe_list = lttng_get_probe_list_head();
2249 /*
2250 * For each probe event, if we find that a probe event matches
2251 * our enabler, create an associated lttng_event if not
2252 * already present.
2253 */
2254 list_for_each_entry(probe_desc, probe_list, head) {
2255 for (i = 0; i < probe_desc->nr_events; i++) {
2256 int found = 0;
2257 struct hlist_head *head;
2258 struct lttng_kernel_event_common *event;
2259 struct lttng_kernel_event_common_private *event_priv;
2260
2261 desc = probe_desc->event_desc[i];
2262 if (!lttng_desc_match_enabler(desc, event_enabler))
2263 continue;
2264
2265 /*
2266 * Check if already created.
2267 */
2268 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
2269 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
2270 if (lttng_event_enabler_desc_match_event(event_enabler, desc, event_priv->pub))
2271 found = 1;
2272 }
2273 if (found)
2274 continue;
2275
2276 /*
2277 * We need to create an event for this event probe.
2278 */
2279 event = _lttng_kernel_event_create(event_enabler, desc);
2280 if (!event) {
2281 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2282 probe_desc->event_desc[i]->event_name);
2283 }
2284 }
2285 }
2286 }
2287
2288 static
2289 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler_common *event_enabler)
2290 {
2291 int ret;
2292
2293 ret = lttng_syscalls_register_event(event_enabler);
2294 WARN_ON_ONCE(ret);
2295 }
2296
2297 /*
2298 * Create event if it is missing and present in the list of tracepoint probes.
2299 * Should be called with sessions mutex held.
2300 */
2301 static
2302 void lttng_create_event_if_missing(struct lttng_event_enabler_common *event_enabler)
2303 {
2304 switch (event_enabler->event_param.instrumentation) {
2305 case LTTNG_KERNEL_ABI_TRACEPOINT:
2306 lttng_create_tracepoint_event_if_missing(event_enabler);
2307 break;
2308
2309 case LTTNG_KERNEL_ABI_SYSCALL:
2310 lttng_create_syscall_event_if_missing(event_enabler);
2311 break;
2312
2313 default:
2314 WARN_ON_ONCE(1);
2315 break;
2316 }
2317 }
2318
2319 static
2320 void lttng_event_enabler_init_event_filter(struct lttng_event_enabler_common *event_enabler,
2321 struct lttng_kernel_event_common *event)
2322 {
2323 /* Link filter bytecodes if not linked yet. */
2324 lttng_enabler_link_bytecode(event->priv->desc, lttng_static_ctx,
2325 &event->priv->filter_bytecode_runtime_head, &event_enabler->filter_bytecode_head);
2326 }
2327
2328 static
2329 void lttng_event_enabler_init_event_capture(struct lttng_event_enabler_common *event_enabler,
2330 struct lttng_kernel_event_common *event)
2331 {
2332 switch (event_enabler->enabler_type) {
2333 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2334 break;
2335 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2336 {
2337 struct lttng_event_notifier_enabler *event_notifier_enabler =
2338 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2339 struct lttng_kernel_event_notifier *event_notifier =
2340 container_of(event, struct lttng_kernel_event_notifier, parent);
2341
2342 /* Link capture bytecodes if not linked yet. */
2343 lttng_enabler_link_bytecode(event->priv->desc,
2344 lttng_static_ctx, &event_notifier->priv->capture_bytecode_runtime_head,
2345 &event_notifier_enabler->capture_bytecode_head);
2346 event_notifier->priv->num_captures = event_notifier_enabler->num_captures;
2347 break;
2348 }
2349 default:
2350 WARN_ON_ONCE(1);
2351 }
2352 }
2353
2354 /*
2355 * Create events associated with an event_enabler (if not already present),
2356 * and add backward reference from the event to the enabler.
2357 * Should be called with sessions mutex held.
2358 */
2359 static
2360 int lttng_event_enabler_ref_events(struct lttng_event_enabler_common *event_enabler)
2361 {
2362 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(event_enabler);
2363 struct lttng_kernel_event_common_private *event_priv;
2364
2365 lttng_syscall_table_set_wildcard_all(event_enabler);
2366
2367 /* First ensure that probe events are created for this enabler. */
2368 lttng_create_event_if_missing(event_enabler);
2369
2370 /* Link the created event with its associated enabler. */
2371 list_for_each_entry(event_priv, event_list_head, node) {
2372 struct lttng_kernel_event_common *event = event_priv->pub;
2373 struct lttng_enabler_ref *enabler_ref;
2374
2375 if (!lttng_event_enabler_match_event(event_enabler, event))
2376 continue;
2377
2378 enabler_ref = lttng_enabler_ref(&event_priv->enablers_ref_head, event_enabler);
2379 if (!enabler_ref) {
2380 /*
2381 * If no backward ref, create it.
2382 * Add backward ref from event_notifier to enabler.
2383 */
2384 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2385 if (!enabler_ref)
2386 return -ENOMEM;
2387
2388 enabler_ref->ref = event_enabler;
2389 list_add(&enabler_ref->node, &event_priv->enablers_ref_head);
2390 }
2391
2392 lttng_event_enabler_init_event_filter(event_enabler, event);
2393 lttng_event_enabler_init_event_capture(event_enabler, event);
2394 }
2395 return 0;
2396 }
2397
2398 /*
2399 * Called at module load: connect the probe on all enablers matching
2400 * this event.
2401 * Called with sessions lock held.
2402 */
2403 int lttng_fix_pending_events(void)
2404 {
2405 struct lttng_kernel_session_private *session_priv;
2406
2407 list_for_each_entry(session_priv, &sessions, list)
2408 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2409 return 0;
2410 }
2411
2412 static bool lttng_event_notifier_group_has_active_event_notifiers(
2413 struct lttng_event_notifier_group *event_notifier_group)
2414 {
2415 struct lttng_event_enabler_common *event_enabler;
2416
2417 list_for_each_entry(event_enabler, &event_notifier_group->enablers_head, node) {
2418 if (event_enabler->enabled)
2419 return true;
2420 }
2421 return false;
2422 }
2423
2424 bool lttng_event_notifier_active(void)
2425 {
2426 struct lttng_event_notifier_group *event_notifier_group;
2427
2428 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2429 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2430 return true;
2431 }
2432 return false;
2433 }
2434
2435 int lttng_fix_pending_event_notifiers(void)
2436 {
2437 struct lttng_event_notifier_group *event_notifier_group;
2438
2439 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2440 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2441 return 0;
2442 }
2443
2444 struct lttng_event_recorder_enabler *lttng_event_recorder_enabler_create(
2445 enum lttng_enabler_format_type format_type,
2446 struct lttng_kernel_abi_event *event_param,
2447 struct lttng_kernel_channel_buffer *chan)
2448 {
2449 struct lttng_event_recorder_enabler *event_enabler;
2450
2451 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2452 if (!event_enabler)
2453 return NULL;
2454 event_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_RECORDER;
2455 event_enabler->parent.format_type = format_type;
2456 INIT_LIST_HEAD(&event_enabler->parent.filter_bytecode_head);
2457 memcpy(&event_enabler->parent.event_param, event_param,
2458 sizeof(event_enabler->parent.event_param));
2459 event_enabler->chan = chan;
2460 /* ctx left NULL */
2461 event_enabler->parent.enabled = 0;
2462 return event_enabler;
2463 }
2464
2465 void lttng_event_enabler_session_add(struct lttng_kernel_session *session,
2466 struct lttng_event_recorder_enabler *event_enabler)
2467 {
2468 mutex_lock(&sessions_mutex);
2469 list_add(&event_enabler->parent.node, &session->priv->enablers_head);
2470 event_enabler->parent.published = true;
2471 lttng_session_lazy_sync_event_enablers(session);
2472 mutex_unlock(&sessions_mutex);
2473 }
2474
2475 int lttng_event_enabler_enable(struct lttng_event_enabler_common *event_enabler)
2476 {
2477 mutex_lock(&sessions_mutex);
2478 event_enabler->enabled = 1;
2479 lttng_event_enabler_sync(event_enabler);
2480 mutex_unlock(&sessions_mutex);
2481 return 0;
2482 }
2483
2484 int lttng_event_enabler_disable(struct lttng_event_enabler_common *event_enabler)
2485 {
2486 mutex_lock(&sessions_mutex);
2487 event_enabler->enabled = 0;
2488 lttng_event_enabler_sync(event_enabler);
2489 mutex_unlock(&sessions_mutex);
2490 return 0;
2491 }
2492
2493 static
2494 int lttng_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *enabler,
2495 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2496 {
2497 struct lttng_kernel_bytecode_node *bytecode_node;
2498 uint32_t bytecode_len;
2499 int ret;
2500
2501 ret = get_user(bytecode_len, &bytecode->len);
2502 if (ret)
2503 return ret;
2504 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2505 GFP_KERNEL);
2506 if (!bytecode_node)
2507 return -ENOMEM;
2508 ret = copy_from_user(&bytecode_node->bc, bytecode,
2509 sizeof(*bytecode) + bytecode_len);
2510 if (ret)
2511 goto error_free;
2512
2513 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2514 bytecode_node->enabler = enabler;
2515 /* Enforce length based on allocated size */
2516 bytecode_node->bc.len = bytecode_len;
2517 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2518
2519 return 0;
2520
2521 error_free:
2522 lttng_kvfree(bytecode_node);
2523 return ret;
2524 }
2525
2526 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *event_enabler,
2527 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2528 {
2529 int ret;
2530 ret = lttng_enabler_attach_filter_bytecode(event_enabler, bytecode);
2531 if (ret)
2532 goto error;
2533 lttng_event_enabler_sync(event_enabler);
2534 return 0;
2535
2536 error:
2537 return ret;
2538 }
2539
2540 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2541 struct lttng_kernel_abi_event_callsite __user *callsite)
2542 {
2543
2544 switch (event->priv->instrumentation) {
2545 case LTTNG_KERNEL_ABI_UPROBE:
2546 return lttng_uprobes_event_add_callsite(event, callsite);
2547 default:
2548 return -EINVAL;
2549 }
2550 }
2551
2552 static
2553 void lttng_enabler_destroy(struct lttng_event_enabler_common *enabler)
2554 {
2555 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2556
2557 /* Destroy filter bytecode */
2558 list_for_each_entry_safe(filter_node, tmp_filter_node,
2559 &enabler->filter_bytecode_head, node) {
2560 lttng_kvfree(filter_node);
2561 }
2562 }
2563
2564 void lttng_event_enabler_destroy(struct lttng_event_enabler_common *event_enabler)
2565 {
2566 lttng_enabler_destroy(event_enabler);
2567 if (event_enabler->published)
2568 list_del(&event_enabler->node);
2569
2570 switch (event_enabler->enabler_type) {
2571 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2572 {
2573 struct lttng_event_recorder_enabler *event_recorder_enabler =
2574 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2575
2576 kfree(event_recorder_enabler);
2577 break;
2578 }
2579 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2580 {
2581 struct lttng_event_notifier_enabler *event_notifier_enabler =
2582 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2583
2584 kfree(event_notifier_enabler);
2585 break;
2586 }
2587 default:
2588 WARN_ON_ONCE(1);
2589 }
2590 }
2591
2592 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2593 enum lttng_enabler_format_type format_type,
2594 struct lttng_kernel_abi_event_notifier *event_notifier_param,
2595 struct lttng_event_notifier_group *event_notifier_group)
2596 {
2597 struct lttng_event_notifier_enabler *event_notifier_enabler;
2598
2599 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2600 if (!event_notifier_enabler)
2601 return NULL;
2602
2603 event_notifier_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_NOTIFIER;
2604 event_notifier_enabler->parent.format_type = format_type;
2605 INIT_LIST_HEAD(&event_notifier_enabler->parent.filter_bytecode_head);
2606 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2607
2608 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2609 event_notifier_enabler->num_captures = 0;
2610
2611 memcpy(&event_notifier_enabler->parent.event_param, &event_notifier_param->event,
2612 sizeof(event_notifier_enabler->parent.event_param));
2613
2614 event_notifier_enabler->parent.enabled = 0;
2615 event_notifier_enabler->parent.user_token = event_notifier_param->event.token;
2616 event_notifier_enabler->group = event_notifier_group;
2617 return event_notifier_enabler;
2618 }
2619
2620 void lttng_event_notifier_enabler_group_add(struct lttng_event_notifier_group *event_notifier_group,
2621 struct lttng_event_notifier_enabler *event_notifier_enabler)
2622 {
2623 mutex_lock(&sessions_mutex);
2624 list_add(&event_notifier_enabler->parent.node, &event_notifier_enabler->group->enablers_head);
2625 event_notifier_enabler->parent.published = true;
2626 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2627 mutex_unlock(&sessions_mutex);
2628 }
2629
2630 int lttng_event_notifier_enabler_enable(
2631 struct lttng_event_notifier_enabler *event_notifier_enabler)
2632 {
2633 mutex_lock(&sessions_mutex);
2634 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2635 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2636 mutex_unlock(&sessions_mutex);
2637 return 0;
2638 }
2639
2640 int lttng_event_notifier_enabler_disable(
2641 struct lttng_event_notifier_enabler *event_notifier_enabler)
2642 {
2643 mutex_lock(&sessions_mutex);
2644 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2645 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2646 mutex_unlock(&sessions_mutex);
2647 return 0;
2648 }
2649
2650 int lttng_event_notifier_enabler_attach_capture_bytecode(
2651 struct lttng_event_notifier_enabler *event_notifier_enabler,
2652 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2653 {
2654 struct lttng_kernel_bytecode_node *bytecode_node;
2655 struct lttng_event_enabler_common *enabler =
2656 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2657 uint32_t bytecode_len;
2658 int ret;
2659
2660 ret = get_user(bytecode_len, &bytecode->len);
2661 if (ret)
2662 return ret;
2663
2664 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2665 GFP_KERNEL);
2666 if (!bytecode_node)
2667 return -ENOMEM;
2668
2669 ret = copy_from_user(&bytecode_node->bc, bytecode,
2670 sizeof(*bytecode) + bytecode_len);
2671 if (ret)
2672 goto error_free;
2673
2674 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2675 bytecode_node->enabler = enabler;
2676
2677 /* Enforce length based on allocated size */
2678 bytecode_node->bc.len = bytecode_len;
2679 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2680
2681 event_notifier_enabler->num_captures++;
2682
2683 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2684 goto end;
2685
2686 error_free:
2687 lttng_kvfree(bytecode_node);
2688 end:
2689 return ret;
2690 }
2691
2692 static
2693 void lttng_event_sync_filter_state(struct lttng_kernel_event_common *event)
2694 {
2695 int has_enablers_without_filter_bytecode = 0, nr_filters = 0;
2696 struct lttng_kernel_bytecode_runtime *runtime;
2697 struct lttng_enabler_ref *enabler_ref;
2698
2699 /* Check if has enablers without bytecode enabled */
2700 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2701 if (enabler_ref->ref->enabled
2702 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2703 has_enablers_without_filter_bytecode = 1;
2704 break;
2705 }
2706 }
2707 event->priv->has_enablers_without_filter_bytecode = has_enablers_without_filter_bytecode;
2708
2709 /* Enable filters */
2710 list_for_each_entry(runtime, &event->priv->filter_bytecode_runtime_head, node) {
2711 lttng_bytecode_sync_state(runtime);
2712 nr_filters++;
2713 }
2714 WRITE_ONCE(event->eval_filter, !(has_enablers_without_filter_bytecode || !nr_filters));
2715 }
2716
2717 static
2718 void lttng_event_sync_capture_state(struct lttng_kernel_event_common *event)
2719 {
2720 switch (event->type) {
2721 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2722 break;
2723 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2724 {
2725 struct lttng_kernel_event_notifier *event_notifier =
2726 container_of(event, struct lttng_kernel_event_notifier, parent);
2727 struct lttng_kernel_bytecode_runtime *runtime;
2728 int nr_captures = 0;
2729
2730 /* Enable captures */
2731 list_for_each_entry(runtime, &event_notifier->priv->capture_bytecode_runtime_head, node) {
2732 lttng_bytecode_sync_state(runtime);
2733 nr_captures++;
2734 }
2735 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2736 break;
2737 }
2738 default:
2739 WARN_ON_ONCE(1);
2740 }
2741 }
2742
2743 static
2744 bool lttng_get_event_enabled_state(struct lttng_kernel_event_common *event)
2745 {
2746 struct lttng_enabler_ref *enabler_ref;
2747 bool enabled = false;
2748
2749 switch (event->priv->instrumentation) {
2750 case LTTNG_KERNEL_ABI_TRACEPOINT:
2751 lttng_fallthrough;
2752 case LTTNG_KERNEL_ABI_SYSCALL:
2753 /* Enable events */
2754 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2755 if (enabler_ref->ref->enabled) {
2756 enabled = true;
2757 break;
2758 }
2759 }
2760 break;
2761 default:
2762 WARN_ON_ONCE(1);
2763 return false;
2764 }
2765
2766 switch (event->type) {
2767 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2768 {
2769 struct lttng_kernel_event_recorder *event_recorder =
2770 container_of(event, struct lttng_kernel_event_recorder, parent);
2771
2772 /*
2773 * Enabled state is based on union of enablers, with
2774 * intersection of session and channel transient enable
2775 * states.
2776 */
2777 return enabled && event_recorder->chan->parent.session->priv->tstate && event_recorder->chan->priv->parent.tstate;
2778 }
2779 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2780 return enabled;
2781 default:
2782 WARN_ON_ONCE(1);
2783 return false;
2784 }
2785 }
2786
2787 static
2788 bool lttng_event_is_lazy_sync(struct lttng_kernel_event_common *event)
2789 {
2790 switch (event->priv->instrumentation) {
2791 case LTTNG_KERNEL_ABI_TRACEPOINT:
2792 lttng_fallthrough;
2793 case LTTNG_KERNEL_ABI_SYSCALL:
2794 return true;
2795
2796 default:
2797 /* Not handled with lazy sync. */
2798 return false;
2799 }
2800 }
2801
2802 /*
2803 * Should be called with sessions mutex held.
2804 */
2805 static
2806 void lttng_sync_event_list(struct list_head *event_enabler_list,
2807 struct list_head *event_list)
2808 {
2809 struct lttng_kernel_event_common_private *event_priv;
2810 struct lttng_event_enabler_common *event_enabler;
2811
2812 list_for_each_entry(event_enabler, event_enabler_list, node)
2813 lttng_event_enabler_ref_events(event_enabler);
2814
2815 /*
2816 * For each event, if at least one of its enablers is enabled,
2817 * and its channel and session transient states are enabled, we
2818 * enable the event, else we disable it.
2819 */
2820 list_for_each_entry(event_priv, event_list, node) {
2821 struct lttng_kernel_event_common *event = event_priv->pub;
2822 bool enabled;
2823
2824 if (!lttng_event_is_lazy_sync(event))
2825 continue;
2826
2827 enabled = lttng_get_event_enabled_state(event);
2828 WRITE_ONCE(event->enabled, enabled);
2829 /*
2830 * Sync tracepoint registration with event enabled state.
2831 */
2832 if (enabled) {
2833 register_event(event);
2834 } else {
2835 _lttng_event_unregister(event);
2836 }
2837
2838 lttng_event_sync_filter_state(event);
2839 lttng_event_sync_capture_state(event);
2840 }
2841 }
2842
2843 /*
2844 * lttng_session_sync_event_enablers should be called just before starting a
2845 * session.
2846 */
2847 static
2848 void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2849 {
2850 lttng_sync_event_list(&session->priv->enablers_head, &session->priv->events);
2851 }
2852
2853 /*
2854 * Apply enablers to session events, adding events to session if need
2855 * be. It is required after each modification applied to an active
2856 * session, and right before session "start".
2857 * "lazy" sync means we only sync if required.
2858 * Should be called with sessions mutex held.
2859 */
2860 static
2861 void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2862 {
2863 /* We can skip if session is not active */
2864 if (!session->active)
2865 return;
2866 lttng_session_sync_event_enablers(session);
2867 }
2868
2869 static
2870 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2871 {
2872 lttng_sync_event_list(&event_notifier_group->enablers_head, &event_notifier_group->event_notifiers_head);
2873 }
2874
2875 static
2876 void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler)
2877 {
2878 switch (event_enabler->enabler_type) {
2879 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2880 {
2881 struct lttng_event_recorder_enabler *event_recorder_enabler =
2882 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2883 lttng_session_lazy_sync_event_enablers(event_recorder_enabler->chan->parent.session);
2884 break;
2885 }
2886 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2887 {
2888 struct lttng_event_notifier_enabler *event_notifier_enabler =
2889 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2890 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2891 break;
2892 }
2893 default:
2894 WARN_ON_ONCE(1);
2895 }
2896 }
2897
2898 /*
2899 * Serialize at most one packet worth of metadata into a metadata
2900 * channel.
2901 * We grab the metadata cache mutex to get exclusive access to our metadata
2902 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2903 * allows us to do racy operations such as looking for remaining space left in
2904 * packet and write, since mutual exclusion protects us from concurrent writes.
2905 * Mutual exclusion on the metadata cache allow us to read the cache content
2906 * without racing against reallocation of the cache by updates.
2907 * Returns the number of bytes written in the channel, 0 if no data
2908 * was written and a negative value on error.
2909 */
2910 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2911 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2912 {
2913 struct lttng_kernel_ring_buffer_ctx ctx;
2914 int ret = 0;
2915 size_t len, reserve_len;
2916
2917 /*
2918 * Ensure we support mutiple get_next / put sequences followed by
2919 * put_next. The metadata cache lock protects reading the metadata
2920 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2921 * "flush" operations on the buffer invoked by different processes.
2922 * Moreover, since the metadata cache memory can be reallocated, we
2923 * need to have exclusive access against updates even though we only
2924 * read it.
2925 */
2926 mutex_lock(&stream->metadata_cache->lock);
2927 WARN_ON(stream->metadata_in < stream->metadata_out);
2928 if (stream->metadata_in != stream->metadata_out)
2929 goto end;
2930
2931 /* Metadata regenerated, change the version. */
2932 if (stream->metadata_cache->version != stream->version)
2933 stream->version = stream->metadata_cache->version;
2934
2935 len = stream->metadata_cache->metadata_written -
2936 stream->metadata_in;
2937 if (!len)
2938 goto end;
2939 reserve_len = min_t(size_t,
2940 stream->transport->ops.priv->packet_avail_size(chan),
2941 len);
2942 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2943 sizeof(char), NULL);
2944 /*
2945 * If reservation failed, return an error to the caller.
2946 */
2947 ret = stream->transport->ops.event_reserve(&ctx);
2948 if (ret != 0) {
2949 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2950 stream->coherent = false;
2951 goto end;
2952 }
2953 stream->transport->ops.event_write(&ctx,
2954 stream->metadata_cache->data + stream->metadata_in,
2955 reserve_len, 1);
2956 stream->transport->ops.event_commit(&ctx);
2957 stream->metadata_in += reserve_len;
2958 if (reserve_len < len)
2959 stream->coherent = false;
2960 else
2961 stream->coherent = true;
2962 ret = reserve_len;
2963
2964 end:
2965 if (coherent)
2966 *coherent = stream->coherent;
2967 mutex_unlock(&stream->metadata_cache->lock);
2968 return ret;
2969 }
2970
2971 static
2972 void lttng_metadata_begin(struct lttng_kernel_session *session)
2973 {
2974 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
2975 mutex_lock(&session->priv->metadata_cache->lock);
2976 }
2977
2978 static
2979 void lttng_metadata_end(struct lttng_kernel_session *session)
2980 {
2981 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2982 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
2983 struct lttng_metadata_stream *stream;
2984
2985 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
2986 wake_up_interruptible(&stream->read_wait);
2987 mutex_unlock(&session->priv->metadata_cache->lock);
2988 }
2989 }
2990
2991 /*
2992 * Write the metadata to the metadata cache.
2993 * Must be called with sessions_mutex held.
2994 * The metadata cache lock protects us from concurrent read access from
2995 * thread outputting metadata content to ring buffer.
2996 * The content of the printf is printed as a single atomic metadata
2997 * transaction.
2998 */
2999 int lttng_metadata_printf(struct lttng_kernel_session *session,
3000 const char *fmt, ...)
3001 {
3002 char *str;
3003 size_t len;
3004 va_list ap;
3005
3006 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
3007
3008 va_start(ap, fmt);
3009 str = kvasprintf(GFP_KERNEL, fmt, ap);
3010 va_end(ap);
3011 if (!str)
3012 return -ENOMEM;
3013
3014 len = strlen(str);
3015 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
3016 if (session->priv->metadata_cache->metadata_written + len >
3017 session->priv->metadata_cache->cache_alloc) {
3018 char *tmp_cache_realloc;
3019 unsigned int tmp_cache_alloc_size;
3020
3021 tmp_cache_alloc_size = max_t(unsigned int,
3022 session->priv->metadata_cache->cache_alloc + len,
3023 session->priv->metadata_cache->cache_alloc << 1);
3024 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
3025 if (!tmp_cache_realloc)
3026 goto err;
3027 if (session->priv->metadata_cache->data) {
3028 memcpy(tmp_cache_realloc,
3029 session->priv->metadata_cache->data,
3030 session->priv->metadata_cache->cache_alloc);
3031 vfree(session->priv->metadata_cache->data);
3032 }
3033
3034 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
3035 session->priv->metadata_cache->data = tmp_cache_realloc;
3036 }
3037 memcpy(session->priv->metadata_cache->data +
3038 session->priv->metadata_cache->metadata_written,
3039 str, len);
3040 session->priv->metadata_cache->metadata_written += len;
3041 kfree(str);
3042
3043 return 0;
3044
3045 err:
3046 kfree(str);
3047 return -ENOMEM;
3048 }
3049
3050 static
3051 int print_tabs(struct lttng_kernel_session *session, size_t nesting)
3052 {
3053 size_t i;
3054
3055 for (i = 0; i < nesting; i++) {
3056 int ret;
3057
3058 ret = lttng_metadata_printf(session, " ");
3059 if (ret) {
3060 return ret;
3061 }
3062 }
3063 return 0;
3064 }
3065
3066 static
3067 int lttng_field_name_statedump(struct lttng_kernel_session *session,
3068 const struct lttng_kernel_event_field *field,
3069 size_t nesting)
3070 {
3071 return lttng_metadata_printf(session, " _%s;\n", field->name);
3072 }
3073
3074 static
3075 int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
3076 const struct lttng_kernel_type_integer *type,
3077 enum lttng_kernel_string_encoding parent_encoding,
3078 size_t nesting)
3079 {
3080 int ret;
3081
3082 ret = print_tabs(session, nesting);
3083 if (ret)
3084 return ret;
3085 ret = lttng_metadata_printf(session,
3086 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
3087 type->size,
3088 type->alignment,
3089 type->signedness,
3090 (parent_encoding == lttng_kernel_string_encoding_none)
3091 ? "none"
3092 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
3093 ? "UTF8"
3094 : "ASCII",
3095 type->base,
3096 #if __BYTE_ORDER == __BIG_ENDIAN
3097 type->reverse_byte_order ? " byte_order = le;" : ""
3098 #else
3099 type->reverse_byte_order ? " byte_order = be;" : ""
3100 #endif
3101 );
3102 return ret;
3103 }
3104
3105 /*
3106 * Must be called with sessions_mutex held.
3107 */
3108 static
3109 int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
3110 const struct lttng_kernel_type_struct *type,
3111 size_t nesting)
3112 {
3113 const char *prev_field_name = NULL;
3114 int ret;
3115 uint32_t i, nr_fields;
3116 unsigned int alignment;
3117
3118 ret = print_tabs(session, nesting);
3119 if (ret)
3120 return ret;
3121 ret = lttng_metadata_printf(session,
3122 "struct {\n");
3123 if (ret)
3124 return ret;
3125 nr_fields = type->nr_fields;
3126 for (i = 0; i < nr_fields; i++) {
3127 const struct lttng_kernel_event_field *iter_field;
3128
3129 iter_field = type->fields[i];
3130 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
3131 if (ret)
3132 return ret;
3133 }
3134 ret = print_tabs(session, nesting);
3135 if (ret)
3136 return ret;
3137 alignment = type->alignment;
3138 if (alignment) {
3139 ret = lttng_metadata_printf(session,
3140 "} align(%u)",
3141 alignment);
3142 } else {
3143 ret = lttng_metadata_printf(session,
3144 "}");
3145 }
3146 return ret;
3147 }
3148
3149 /*
3150 * Must be called with sessions_mutex held.
3151 */
3152 static
3153 int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
3154 const struct lttng_kernel_event_field *field,
3155 size_t nesting)
3156 {
3157 int ret;
3158
3159 ret = _lttng_struct_type_statedump(session,
3160 lttng_kernel_get_type_struct(field->type), nesting);
3161 if (ret)
3162 return ret;
3163 return lttng_field_name_statedump(session, field, nesting);
3164 }
3165
3166 /*
3167 * Must be called with sessions_mutex held.
3168 */
3169 static
3170 int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
3171 const struct lttng_kernel_type_variant *type,
3172 size_t nesting,
3173 const char *prev_field_name)
3174 {
3175 const char *tag_name;
3176 int ret;
3177 uint32_t i, nr_choices;
3178
3179 tag_name = type->tag_name;
3180 if (!tag_name)
3181 tag_name = prev_field_name;
3182 if (!tag_name)
3183 return -EINVAL;
3184 /*
3185 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3186 */
3187 if (type->alignment != 0)
3188 return -EINVAL;
3189 ret = print_tabs(session, nesting);
3190 if (ret)
3191 return ret;
3192 ret = lttng_metadata_printf(session,
3193 "variant <_%s> {\n",
3194 tag_name);
3195 if (ret)
3196 return ret;
3197 nr_choices = type->nr_choices;
3198 for (i = 0; i < nr_choices; i++) {
3199 const struct lttng_kernel_event_field *iter_field;
3200
3201 iter_field = type->choices[i];
3202 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3203 if (ret)
3204 return ret;
3205 }
3206 ret = print_tabs(session, nesting);
3207 if (ret)
3208 return ret;
3209 ret = lttng_metadata_printf(session,
3210 "}");
3211 return ret;
3212 }
3213
3214 /*
3215 * Must be called with sessions_mutex held.
3216 */
3217 static
3218 int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3219 const struct lttng_kernel_event_field *field,
3220 size_t nesting,
3221 const char *prev_field_name)
3222 {
3223 int ret;
3224
3225 ret = _lttng_variant_type_statedump(session,
3226 lttng_kernel_get_type_variant(field->type), nesting,
3227 prev_field_name);
3228 if (ret)
3229 return ret;
3230 return lttng_field_name_statedump(session, field, nesting);
3231 }
3232
3233 /*
3234 * Must be called with sessions_mutex held.
3235 */
3236 static
3237 int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3238 const struct lttng_kernel_event_field *field,
3239 size_t nesting)
3240 {
3241 int ret;
3242 const struct lttng_kernel_type_array *array_type;
3243 const struct lttng_kernel_type_common *elem_type;
3244
3245 array_type = lttng_kernel_get_type_array(field->type);
3246 WARN_ON_ONCE(!array_type);
3247
3248 if (array_type->alignment) {
3249 ret = print_tabs(session, nesting);
3250 if (ret)
3251 return ret;
3252 ret = lttng_metadata_printf(session,
3253 "struct { } align(%u) _%s_padding;\n",
3254 array_type->alignment * CHAR_BIT,
3255 field->name);
3256 if (ret)
3257 return ret;
3258 }
3259 /*
3260 * Nested compound types: Only array of structures and variants are
3261 * currently supported.
3262 */
3263 elem_type = array_type->elem_type;
3264 switch (elem_type->type) {
3265 case lttng_kernel_type_integer:
3266 case lttng_kernel_type_struct:
3267 case lttng_kernel_type_variant:
3268 ret = _lttng_type_statedump(session, elem_type,
3269 array_type->encoding, nesting);
3270 if (ret)
3271 return ret;
3272 break;
3273
3274 default:
3275 return -EINVAL;
3276 }
3277 ret = lttng_metadata_printf(session,
3278 " _%s[%u];\n",
3279 field->name,
3280 array_type->length);
3281 return ret;
3282 }
3283
3284 /*
3285 * Must be called with sessions_mutex held.
3286 */
3287 static
3288 int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3289 const struct lttng_kernel_event_field *field,
3290 size_t nesting,
3291 const char *prev_field_name)
3292 {
3293 int ret;
3294 const char *length_name;
3295 const struct lttng_kernel_type_sequence *sequence_type;
3296 const struct lttng_kernel_type_common *elem_type;
3297
3298 sequence_type = lttng_kernel_get_type_sequence(field->type);
3299 WARN_ON_ONCE(!sequence_type);
3300
3301 length_name = sequence_type->length_name;
3302 if (!length_name)
3303 length_name = prev_field_name;
3304 if (!length_name)
3305 return -EINVAL;
3306
3307 if (sequence_type->alignment) {
3308 ret = print_tabs(session, nesting);
3309 if (ret)
3310 return ret;
3311 ret = lttng_metadata_printf(session,
3312 "struct { } align(%u) _%s_padding;\n",
3313 sequence_type->alignment * CHAR_BIT,
3314 field->name);
3315 if (ret)
3316 return ret;
3317 }
3318
3319 /*
3320 * Nested compound types: Only array of structures and variants are
3321 * currently supported.
3322 */
3323 elem_type = sequence_type->elem_type;
3324 switch (elem_type->type) {
3325 case lttng_kernel_type_integer:
3326 case lttng_kernel_type_struct:
3327 case lttng_kernel_type_variant:
3328 ret = _lttng_type_statedump(session, elem_type,
3329 sequence_type->encoding, nesting);
3330 if (ret)
3331 return ret;
3332 break;
3333
3334 default:
3335 return -EINVAL;
3336 }
3337 ret = lttng_metadata_printf(session,
3338 " _%s[ _%s ];\n",
3339 field->name,
3340 length_name);
3341 return ret;
3342 }
3343
3344 /*
3345 * Must be called with sessions_mutex held.
3346 */
3347 static
3348 int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3349 const struct lttng_kernel_type_enum *type,
3350 size_t nesting)
3351 {
3352 const struct lttng_kernel_enum_desc *enum_desc;
3353 const struct lttng_kernel_type_common *container_type;
3354 int ret;
3355 unsigned int i, nr_entries;
3356
3357 container_type = type->container_type;
3358 if (container_type->type != lttng_kernel_type_integer) {
3359 ret = -EINVAL;
3360 goto end;
3361 }
3362 enum_desc = type->desc;
3363 nr_entries = enum_desc->nr_entries;
3364
3365 ret = print_tabs(session, nesting);
3366 if (ret)
3367 goto end;
3368 ret = lttng_metadata_printf(session, "enum : ");
3369 if (ret)
3370 goto end;
3371 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3372 lttng_kernel_string_encoding_none, 0);
3373 if (ret)
3374 goto end;
3375 ret = lttng_metadata_printf(session, " {\n");
3376 if (ret)
3377 goto end;
3378 /* Dump all entries */
3379 for (i = 0; i < nr_entries; i++) {
3380 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3381 int j, len;
3382
3383 ret = print_tabs(session, nesting + 1);
3384 if (ret)
3385 goto end;
3386 ret = lttng_metadata_printf(session,
3387 "\"");
3388 if (ret)
3389 goto end;
3390 len = strlen(entry->string);
3391 /* Escape the character '"' */
3392 for (j = 0; j < len; j++) {
3393 char c = entry->string[j];
3394
3395 switch (c) {
3396 case '"':
3397 ret = lttng_metadata_printf(session,
3398 "\\\"");
3399 break;
3400 case '\\':
3401 ret = lttng_metadata_printf(session,
3402 "\\\\");
3403 break;
3404 default:
3405 ret = lttng_metadata_printf(session,
3406 "%c", c);
3407 break;
3408 }
3409 if (ret)
3410 goto end;
3411 }
3412 ret = lttng_metadata_printf(session, "\"");
3413 if (ret)
3414 goto end;
3415
3416 if (entry->options.is_auto) {
3417 ret = lttng_metadata_printf(session, ",\n");
3418 if (ret)
3419 goto end;
3420 } else {
3421 ret = lttng_metadata_printf(session,
3422 " = ");
3423 if (ret)
3424 goto end;
3425 if (entry->start.signedness)
3426 ret = lttng_metadata_printf(session,
3427 "%lld", (long long) entry->start.value);
3428 else
3429 ret = lttng_metadata_printf(session,
3430 "%llu", entry->start.value);
3431 if (ret)
3432 goto end;
3433 if (entry->start.signedness == entry->end.signedness &&
3434 entry->start.value
3435 == entry->end.value) {
3436 ret = lttng_metadata_printf(session,
3437 ",\n");
3438 } else {
3439 if (entry->end.signedness) {
3440 ret = lttng_metadata_printf(session,
3441 " ... %lld,\n",
3442 (long long) entry->end.value);
3443 } else {
3444 ret = lttng_metadata_printf(session,
3445 " ... %llu,\n",
3446 entry->end.value);
3447 }
3448 }
3449 if (ret)
3450 goto end;
3451 }
3452 }
3453 ret = print_tabs(session, nesting);
3454 if (ret)
3455 goto end;
3456 ret = lttng_metadata_printf(session, "}");
3457 end:
3458 return ret;
3459 }
3460
3461 /*
3462 * Must be called with sessions_mutex held.
3463 */
3464 static
3465 int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3466 const struct lttng_kernel_event_field *field,
3467 size_t nesting)
3468 {
3469 int ret;
3470 const struct lttng_kernel_type_enum *enum_type;
3471
3472 enum_type = lttng_kernel_get_type_enum(field->type);
3473 WARN_ON_ONCE(!enum_type);
3474 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3475 if (ret)
3476 return ret;
3477 return lttng_field_name_statedump(session, field, nesting);
3478 }
3479
3480 static
3481 int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3482 const struct lttng_kernel_event_field *field,
3483 size_t nesting)
3484 {
3485 int ret;
3486
3487 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3488 lttng_kernel_string_encoding_none, nesting);
3489 if (ret)
3490 return ret;
3491 return lttng_field_name_statedump(session, field, nesting);
3492 }
3493
3494 static
3495 int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3496 const struct lttng_kernel_type_string *type,
3497 size_t nesting)
3498 {
3499 int ret;
3500
3501 /* Default encoding is UTF8 */
3502 ret = print_tabs(session, nesting);
3503 if (ret)
3504 return ret;
3505 ret = lttng_metadata_printf(session,
3506 "string%s",
3507 type->encoding == lttng_kernel_string_encoding_ASCII ?
3508 " { encoding = ASCII; }" : "");
3509 return ret;
3510 }
3511
3512 static
3513 int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3514 const struct lttng_kernel_event_field *field,
3515 size_t nesting)
3516 {
3517 const struct lttng_kernel_type_string *string_type;
3518 int ret;
3519
3520 string_type = lttng_kernel_get_type_string(field->type);
3521 WARN_ON_ONCE(!string_type);
3522 ret = _lttng_string_type_statedump(session, string_type, nesting);
3523 if (ret)
3524 return ret;
3525 return lttng_field_name_statedump(session, field, nesting);
3526 }
3527
3528 /*
3529 * Must be called with sessions_mutex held.
3530 */
3531 static
3532 int _lttng_type_statedump(struct lttng_kernel_session *session,
3533 const struct lttng_kernel_type_common *type,
3534 enum lttng_kernel_string_encoding parent_encoding,
3535 size_t nesting)
3536 {
3537 int ret = 0;
3538
3539 switch (type->type) {
3540 case lttng_kernel_type_integer:
3541 ret = _lttng_integer_type_statedump(session,
3542 lttng_kernel_get_type_integer(type),
3543 parent_encoding, nesting);
3544 break;
3545 case lttng_kernel_type_enum:
3546 ret = _lttng_enum_type_statedump(session,
3547 lttng_kernel_get_type_enum(type),
3548 nesting);
3549 break;
3550 case lttng_kernel_type_string:
3551 ret = _lttng_string_type_statedump(session,
3552 lttng_kernel_get_type_string(type),
3553 nesting);
3554 break;
3555 case lttng_kernel_type_struct:
3556 ret = _lttng_struct_type_statedump(session,
3557 lttng_kernel_get_type_struct(type),
3558 nesting);
3559 break;
3560 case lttng_kernel_type_variant:
3561 ret = _lttng_variant_type_statedump(session,
3562 lttng_kernel_get_type_variant(type),
3563 nesting, NULL);
3564 break;
3565
3566 /* Nested arrays and sequences are not supported yet. */
3567 case lttng_kernel_type_array:
3568 case lttng_kernel_type_sequence:
3569 default:
3570 WARN_ON_ONCE(1);
3571 return -EINVAL;
3572 }
3573 return ret;
3574 }
3575
3576 /*
3577 * Must be called with sessions_mutex held.
3578 */
3579 static
3580 int _lttng_field_statedump(struct lttng_kernel_session *session,
3581 const struct lttng_kernel_event_field *field,
3582 size_t nesting,
3583 const char **prev_field_name_p)
3584 {
3585 const char *prev_field_name = NULL;
3586 int ret = 0;
3587
3588 if (prev_field_name_p)
3589 prev_field_name = *prev_field_name_p;
3590 switch (field->type->type) {
3591 case lttng_kernel_type_integer:
3592 ret = _lttng_integer_field_statedump(session, field, nesting);
3593 break;
3594 case lttng_kernel_type_enum:
3595 ret = _lttng_enum_field_statedump(session, field, nesting);
3596 break;
3597 case lttng_kernel_type_string:
3598 ret = _lttng_string_field_statedump(session, field, nesting);
3599 break;
3600 case lttng_kernel_type_struct:
3601 ret = _lttng_struct_field_statedump(session, field, nesting);
3602 break;
3603 case lttng_kernel_type_array:
3604 ret = _lttng_array_field_statedump(session, field, nesting);
3605 break;
3606 case lttng_kernel_type_sequence:
3607 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3608 break;
3609 case lttng_kernel_type_variant:
3610 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3611 break;
3612
3613 default:
3614 WARN_ON_ONCE(1);
3615 return -EINVAL;
3616 }
3617 if (prev_field_name_p)
3618 *prev_field_name_p = field->name;
3619 return ret;
3620 }
3621
3622 static
3623 int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3624 struct lttng_kernel_ctx *ctx)
3625 {
3626 const char *prev_field_name = NULL;
3627 int ret = 0;
3628 int i;
3629
3630 if (!ctx)
3631 return 0;
3632 for (i = 0; i < ctx->nr_fields; i++) {
3633 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3634
3635 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3636 if (ret)
3637 return ret;
3638 }
3639 return ret;
3640 }
3641
3642 static
3643 int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3644 struct lttng_kernel_event_recorder *event_recorder)
3645 {
3646 const char *prev_field_name = NULL;
3647 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3648 int ret = 0;
3649 int i;
3650
3651 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3652 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3653
3654 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3655 if (ret)
3656 return ret;
3657 }
3658 return ret;
3659 }
3660
3661 /*
3662 * Must be called with sessions_mutex held.
3663 * The entire event metadata is printed as a single atomic metadata
3664 * transaction.
3665 */
3666 static
3667 int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
3668 struct lttng_kernel_channel_buffer *chan,
3669 struct lttng_kernel_event_recorder *event_recorder)
3670 {
3671 int ret = 0;
3672
3673 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3674 return 0;
3675 if (chan->priv->channel_type == METADATA_CHANNEL)
3676 return 0;
3677
3678 lttng_metadata_begin(session);
3679
3680 ret = lttng_metadata_printf(session,
3681 "event {\n"
3682 " name = \"%s\";\n"
3683 " id = %u;\n"
3684 " stream_id = %u;\n",
3685 event_recorder->priv->parent.desc->event_name,
3686 event_recorder->priv->id,
3687 event_recorder->chan->priv->id);
3688 if (ret)
3689 goto end;
3690
3691 ret = lttng_metadata_printf(session,
3692 " fields := struct {\n"
3693 );
3694 if (ret)
3695 goto end;
3696
3697 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3698 if (ret)
3699 goto end;
3700
3701 /*
3702 * LTTng space reservation can only reserve multiples of the
3703 * byte size.
3704 */
3705 ret = lttng_metadata_printf(session,
3706 " };\n"
3707 "};\n\n");
3708 if (ret)
3709 goto end;
3710
3711 event_recorder->priv->metadata_dumped = 1;
3712 end:
3713 lttng_metadata_end(session);
3714 return ret;
3715
3716 }
3717
3718 /*
3719 * Must be called with sessions_mutex held.
3720 * The entire channel metadata is printed as a single atomic metadata
3721 * transaction.
3722 */
3723 static
3724 int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3725 struct lttng_kernel_channel_buffer *chan)
3726 {
3727 int ret = 0;
3728
3729 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3730 return 0;
3731
3732 if (chan->priv->channel_type == METADATA_CHANNEL)
3733 return 0;
3734
3735 lttng_metadata_begin(session);
3736
3737 WARN_ON_ONCE(!chan->priv->header_type);
3738 ret = lttng_metadata_printf(session,
3739 "stream {\n"
3740 " id = %u;\n"
3741 " event.header := %s;\n"
3742 " packet.context := struct packet_context;\n",
3743 chan->priv->id,
3744 chan->priv->header_type == 1 ? "struct event_header_compact" :
3745 "struct event_header_large");
3746 if (ret)
3747 goto end;
3748
3749 if (chan->priv->ctx) {
3750 ret = lttng_metadata_printf(session,
3751 " event.context := struct {\n");
3752 if (ret)
3753 goto end;
3754 }
3755 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3756 if (ret)
3757 goto end;
3758 if (chan->priv->ctx) {
3759 ret = lttng_metadata_printf(session,
3760 " };\n");
3761 if (ret)
3762 goto end;
3763 }
3764
3765 ret = lttng_metadata_printf(session,
3766 "};\n\n");
3767
3768 chan->priv->metadata_dumped = 1;
3769 end:
3770 lttng_metadata_end(session);
3771 return ret;
3772 }
3773
3774 /*
3775 * Must be called with sessions_mutex held.
3776 */
3777 static
3778 int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3779 {
3780 return lttng_metadata_printf(session,
3781 "struct packet_context {\n"
3782 " uint64_clock_monotonic_t timestamp_begin;\n"
3783 " uint64_clock_monotonic_t timestamp_end;\n"
3784 " uint64_t content_size;\n"
3785 " uint64_t packet_size;\n"
3786 " uint64_t packet_seq_num;\n"
3787 " unsigned long events_discarded;\n"
3788 " uint32_t cpu_id;\n"
3789 "};\n\n"
3790 );
3791 }
3792
3793 /*
3794 * Compact header:
3795 * id: range: 0 - 30.
3796 * id 31 is reserved to indicate an extended header.
3797 *
3798 * Large header:
3799 * id: range: 0 - 65534.
3800 * id 65535 is reserved to indicate an extended header.
3801 *
3802 * Must be called with sessions_mutex held.
3803 */
3804 static
3805 int _lttng_event_header_declare(struct lttng_kernel_session *session)
3806 {
3807 return lttng_metadata_printf(session,
3808 "struct event_header_compact {\n"
3809 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3810 " variant <id> {\n"
3811 " struct {\n"
3812 " uint27_clock_monotonic_t timestamp;\n"
3813 " } compact;\n"
3814 " struct {\n"
3815 " uint32_t id;\n"
3816 " uint64_clock_monotonic_t timestamp;\n"
3817 " } extended;\n"
3818 " } v;\n"
3819 "} align(%u);\n"
3820 "\n"
3821 "struct event_header_large {\n"
3822 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3823 " variant <id> {\n"
3824 " struct {\n"
3825 " uint32_clock_monotonic_t timestamp;\n"
3826 " } compact;\n"
3827 " struct {\n"
3828 " uint32_t id;\n"
3829 " uint64_clock_monotonic_t timestamp;\n"
3830 " } extended;\n"
3831 " } v;\n"
3832 "} align(%u);\n\n",
3833 lttng_alignof(uint32_t) * CHAR_BIT,
3834 lttng_alignof(uint16_t) * CHAR_BIT
3835 );
3836 }
3837
3838 /*
3839 * Approximation of NTP time of day to clock monotonic correlation,
3840 * taken at start of trace.
3841 * Yes, this is only an approximation. Yes, we can (and will) do better
3842 * in future versions.
3843 * This function may return a negative offset. It may happen if the
3844 * system sets the REALTIME clock to 0 after boot.
3845 *
3846 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3847 * y2038 compliant.
3848 */
3849 static
3850 int64_t measure_clock_offset(void)
3851 {
3852 uint64_t monotonic_avg, monotonic[2], realtime;
3853 uint64_t tcf = trace_clock_freq();
3854 int64_t offset;
3855 unsigned long flags;
3856 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3857 struct timespec64 rts = { 0, 0 };
3858 #else
3859 struct timespec rts = { 0, 0 };
3860 #endif
3861
3862 /* Disable interrupts to increase correlation precision. */
3863 local_irq_save(flags);
3864 monotonic[0] = trace_clock_read64();
3865 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3866 ktime_get_real_ts64(&rts);
3867 #else
3868 getnstimeofday(&rts);
3869 #endif
3870 monotonic[1] = trace_clock_read64();
3871 local_irq_restore(flags);
3872
3873 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3874 realtime = (uint64_t) rts.tv_sec * tcf;
3875 if (tcf == NSEC_PER_SEC) {
3876 realtime += rts.tv_nsec;
3877 } else {
3878 uint64_t n = rts.tv_nsec * tcf;
3879
3880 do_div(n, NSEC_PER_SEC);
3881 realtime += n;
3882 }
3883 offset = (int64_t) realtime - monotonic_avg;
3884 return offset;
3885 }
3886
3887 static
3888 int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3889 {
3890 int ret = 0;
3891 size_t i;
3892 char cur;
3893
3894 i = 0;
3895 cur = string[i];
3896 while (cur != '\0') {
3897 switch (cur) {
3898 case '\n':
3899 ret = lttng_metadata_printf(session, "%s", "\\n");
3900 break;
3901 case '\\':
3902 case '"':
3903 ret = lttng_metadata_printf(session, "%c", '\\');
3904 if (ret)
3905 goto error;
3906 /* We still print the current char */
3907 lttng_fallthrough;
3908 default:
3909 ret = lttng_metadata_printf(session, "%c", cur);
3910 break;
3911 }
3912
3913 if (ret)
3914 goto error;
3915
3916 cur = string[++i];
3917 }
3918 error:
3919 return ret;
3920 }
3921
3922 static
3923 int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3924 const char *field_value)
3925 {
3926 int ret;
3927
3928 ret = lttng_metadata_printf(session, " %s = \"", field);
3929 if (ret)
3930 goto error;
3931
3932 ret = print_escaped_ctf_string(session, field_value);
3933 if (ret)
3934 goto error;
3935
3936 ret = lttng_metadata_printf(session, "\";\n");
3937
3938 error:
3939 return ret;
3940 }
3941
3942 /*
3943 * Output metadata into this session's metadata buffers.
3944 * Must be called with sessions_mutex held.
3945 */
3946 static
3947 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3948 {
3949 unsigned char *uuid_c = session->priv->uuid.b;
3950 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3951 const char *product_uuid;
3952 struct lttng_kernel_channel_buffer_private *chan_priv;
3953 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3954 int ret = 0;
3955
3956 if (!LTTNG_READ_ONCE(session->active))
3957 return 0;
3958
3959 lttng_metadata_begin(session);
3960
3961 if (session->priv->metadata_dumped)
3962 goto skip_session;
3963
3964 snprintf(uuid_s, sizeof(uuid_s),
3965 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3966 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3967 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3968 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3969 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3970
3971 ret = lttng_metadata_printf(session,
3972 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3973 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3974 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3975 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3976 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3977 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3978 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3979 "\n"
3980 "trace {\n"
3981 " major = %u;\n"
3982 " minor = %u;\n"
3983 " uuid = \"%s\";\n"
3984 " byte_order = %s;\n"
3985 " packet.header := struct {\n"
3986 " uint32_t magic;\n"
3987 " uint8_t uuid[16];\n"
3988 " uint32_t stream_id;\n"
3989 " uint64_t stream_instance_id;\n"
3990 " };\n"
3991 "};\n\n",
3992 lttng_alignof(uint8_t) * CHAR_BIT,
3993 lttng_alignof(uint16_t) * CHAR_BIT,
3994 lttng_alignof(uint32_t) * CHAR_BIT,
3995 lttng_alignof(uint64_t) * CHAR_BIT,
3996 sizeof(unsigned long) * CHAR_BIT,
3997 lttng_alignof(unsigned long) * CHAR_BIT,
3998 CTF_SPEC_MAJOR,
3999 CTF_SPEC_MINOR,
4000 uuid_s,
4001 #if __BYTE_ORDER == __BIG_ENDIAN
4002 "be"
4003 #else
4004 "le"
4005 #endif
4006 );
4007 if (ret)
4008 goto end;
4009
4010 ret = lttng_metadata_printf(session,
4011 "env {\n"
4012 " hostname = \"%s\";\n"
4013 " domain = \"kernel\";\n"
4014 " sysname = \"%s\";\n"
4015 " kernel_release = \"%s\";\n"
4016 " kernel_version = \"%s\";\n"
4017 " tracer_name = \"lttng-modules\";\n"
4018 " tracer_major = %d;\n"
4019 " tracer_minor = %d;\n"
4020 " tracer_patchlevel = %d;\n"
4021 " trace_buffering_scheme = \"global\";\n",
4022 current->nsproxy->uts_ns->name.nodename,
4023 utsname()->sysname,
4024 utsname()->release,
4025 utsname()->version,
4026 LTTNG_MODULES_MAJOR_VERSION,
4027 LTTNG_MODULES_MINOR_VERSION,
4028 LTTNG_MODULES_PATCHLEVEL_VERSION
4029 );
4030 if (ret)
4031 goto end;
4032
4033 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
4034 if (ret)
4035 goto end;
4036 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
4037 session->priv->creation_time);
4038 if (ret)
4039 goto end;
4040
4041 /* Add the product UUID to the 'env' section */
4042 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
4043 if (product_uuid) {
4044 ret = lttng_metadata_printf(session,
4045 " product_uuid = \"%s\";\n",
4046 product_uuid
4047 );
4048 if (ret)
4049 goto end;
4050 }
4051
4052 /* Close the 'env' section */
4053 ret = lttng_metadata_printf(session, "};\n\n");
4054 if (ret)
4055 goto end;
4056
4057 ret = lttng_metadata_printf(session,
4058 "clock {\n"
4059 " name = \"%s\";\n",
4060 trace_clock_name()
4061 );
4062 if (ret)
4063 goto end;
4064
4065 if (!trace_clock_uuid(clock_uuid_s)) {
4066 ret = lttng_metadata_printf(session,
4067 " uuid = \"%s\";\n",
4068 clock_uuid_s
4069 );
4070 if (ret)
4071 goto end;
4072 }
4073
4074 ret = lttng_metadata_printf(session,
4075 " description = \"%s\";\n"
4076 " freq = %llu; /* Frequency, in Hz */\n"
4077 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
4078 " offset = %lld;\n"
4079 "};\n\n",
4080 trace_clock_description(),
4081 (unsigned long long) trace_clock_freq(),
4082 (long long) measure_clock_offset()
4083 );
4084 if (ret)
4085 goto end;
4086
4087 ret = lttng_metadata_printf(session,
4088 "typealias integer {\n"
4089 " size = 27; align = 1; signed = false;\n"
4090 " map = clock.%s.value;\n"
4091 "} := uint27_clock_monotonic_t;\n"
4092 "\n"
4093 "typealias integer {\n"
4094 " size = 32; align = %u; signed = false;\n"
4095 " map = clock.%s.value;\n"
4096 "} := uint32_clock_monotonic_t;\n"
4097 "\n"
4098 "typealias integer {\n"
4099 " size = 64; align = %u; signed = false;\n"
4100 " map = clock.%s.value;\n"
4101 "} := uint64_clock_monotonic_t;\n\n",
4102 trace_clock_name(),
4103 lttng_alignof(uint32_t) * CHAR_BIT,
4104 trace_clock_name(),
4105 lttng_alignof(uint64_t) * CHAR_BIT,
4106 trace_clock_name()
4107 );
4108 if (ret)
4109 goto end;
4110
4111 ret = _lttng_stream_packet_context_declare(session);
4112 if (ret)
4113 goto end;
4114
4115 ret = _lttng_event_header_declare(session);
4116 if (ret)
4117 goto end;
4118
4119 skip_session:
4120 list_for_each_entry(chan_priv, &session->priv->chan, node) {
4121 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
4122 if (ret)
4123 goto end;
4124 }
4125
4126 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
4127 ret = _lttng_event_metadata_statedump(session, event_recorder_priv->pub->chan,
4128 event_recorder_priv->pub);
4129 if (ret)
4130 goto end;
4131 }
4132 session->priv->metadata_dumped = 1;
4133 end:
4134 lttng_metadata_end(session);
4135 return ret;
4136 }
4137
4138 /**
4139 * lttng_transport_register - LTT transport registration
4140 * @transport: transport structure
4141 *
4142 * Registers a transport which can be used as output to extract the data out of
4143 * LTTng. The module calling this registration function must ensure that no
4144 * trap-inducing code will be executed by the transport functions. E.g.
4145 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
4146 * is made visible to the transport function. This registration acts as a
4147 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
4148 * after its registration must it synchronize the TLBs.
4149 */
4150 void lttng_transport_register(struct lttng_transport *transport)
4151 {
4152 /*
4153 * Make sure no page fault can be triggered by the module about to be
4154 * registered. We deal with this here so we don't have to call
4155 * vmalloc_sync_mappings() in each module's init.
4156 */
4157 wrapper_vmalloc_sync_mappings();
4158
4159 mutex_lock(&sessions_mutex);
4160 list_add_tail(&transport->node, &lttng_transport_list);
4161 mutex_unlock(&sessions_mutex);
4162 }
4163 EXPORT_SYMBOL_GPL(lttng_transport_register);
4164
4165 /**
4166 * lttng_transport_unregister - LTT transport unregistration
4167 * @transport: transport structure
4168 */
4169 void lttng_transport_unregister(struct lttng_transport *transport)
4170 {
4171 mutex_lock(&sessions_mutex);
4172 list_del(&transport->node);
4173 mutex_unlock(&sessions_mutex);
4174 }
4175 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4176
4177 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4178 {
4179 /*
4180 * Make sure no page fault can be triggered by the module about to be
4181 * registered. We deal with this here so we don't have to call
4182 * vmalloc_sync_mappings() in each module's init.
4183 */
4184 wrapper_vmalloc_sync_mappings();
4185
4186 mutex_lock(&sessions_mutex);
4187 list_add_tail(&transport->node, &lttng_counter_transport_list);
4188 mutex_unlock(&sessions_mutex);
4189 }
4190 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4191
4192 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4193 {
4194 mutex_lock(&sessions_mutex);
4195 list_del(&transport->node);
4196 mutex_unlock(&sessions_mutex);
4197 }
4198 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4199
4200 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4201
4202 enum cpuhp_state lttng_hp_prepare;
4203 enum cpuhp_state lttng_hp_online;
4204
4205 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4206 {
4207 struct lttng_cpuhp_node *lttng_node;
4208
4209 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4210 switch (lttng_node->component) {
4211 case LTTNG_RING_BUFFER_FRONTEND:
4212 return 0;
4213 case LTTNG_RING_BUFFER_BACKEND:
4214 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4215 case LTTNG_RING_BUFFER_ITER:
4216 return 0;
4217 case LTTNG_CONTEXT_PERF_COUNTERS:
4218 return 0;
4219 default:
4220 return -EINVAL;
4221 }
4222 }
4223
4224 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4225 {
4226 struct lttng_cpuhp_node *lttng_node;
4227
4228 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4229 switch (lttng_node->component) {
4230 case LTTNG_RING_BUFFER_FRONTEND:
4231 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4232 case LTTNG_RING_BUFFER_BACKEND:
4233 return 0;
4234 case LTTNG_RING_BUFFER_ITER:
4235 return 0;
4236 case LTTNG_CONTEXT_PERF_COUNTERS:
4237 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4238 default:
4239 return -EINVAL;
4240 }
4241 }
4242
4243 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4244 {
4245 struct lttng_cpuhp_node *lttng_node;
4246
4247 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4248 switch (lttng_node->component) {
4249 case LTTNG_RING_BUFFER_FRONTEND:
4250 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4251 case LTTNG_RING_BUFFER_BACKEND:
4252 return 0;
4253 case LTTNG_RING_BUFFER_ITER:
4254 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4255 case LTTNG_CONTEXT_PERF_COUNTERS:
4256 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4257 default:
4258 return -EINVAL;
4259 }
4260 }
4261
4262 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4263 {
4264 struct lttng_cpuhp_node *lttng_node;
4265
4266 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4267 switch (lttng_node->component) {
4268 case LTTNG_RING_BUFFER_FRONTEND:
4269 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4270 case LTTNG_RING_BUFFER_BACKEND:
4271 return 0;
4272 case LTTNG_RING_BUFFER_ITER:
4273 return 0;
4274 case LTTNG_CONTEXT_PERF_COUNTERS:
4275 return 0;
4276 default:
4277 return -EINVAL;
4278 }
4279 }
4280
4281 static int __init lttng_init_cpu_hotplug(void)
4282 {
4283 int ret;
4284
4285 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4286 lttng_hotplug_prepare,
4287 lttng_hotplug_dead);
4288 if (ret < 0) {
4289 return ret;
4290 }
4291 lttng_hp_prepare = ret;
4292 lttng_rb_set_hp_prepare(ret);
4293
4294 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4295 lttng_hotplug_online,
4296 lttng_hotplug_offline);
4297 if (ret < 0) {
4298 cpuhp_remove_multi_state(lttng_hp_prepare);
4299 lttng_hp_prepare = 0;
4300 return ret;
4301 }
4302 lttng_hp_online = ret;
4303 lttng_rb_set_hp_online(ret);
4304
4305 return 0;
4306 }
4307
4308 static void __exit lttng_exit_cpu_hotplug(void)
4309 {
4310 lttng_rb_set_hp_online(0);
4311 cpuhp_remove_multi_state(lttng_hp_online);
4312 lttng_rb_set_hp_prepare(0);
4313 cpuhp_remove_multi_state(lttng_hp_prepare);
4314 }
4315
4316 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4317 static int lttng_init_cpu_hotplug(void)
4318 {
4319 return 0;
4320 }
4321 static void lttng_exit_cpu_hotplug(void)
4322 {
4323 }
4324 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4325
4326 static int __init lttng_events_init(void)
4327 {
4328 int ret;
4329
4330 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4331 if (ret)
4332 return ret;
4333 ret = wrapper_get_pfnblock_flags_mask_init();
4334 if (ret)
4335 return ret;
4336 ret = wrapper_get_pageblock_flags_mask_init();
4337 if (ret)
4338 return ret;
4339 ret = lttng_probes_init();
4340 if (ret)
4341 return ret;
4342 ret = lttng_context_init();
4343 if (ret)
4344 return ret;
4345 ret = lttng_tracepoint_init();
4346 if (ret)
4347 goto error_tp;
4348 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4349 if (!event_recorder_cache) {
4350 ret = -ENOMEM;
4351 goto error_kmem_event_recorder;
4352 }
4353 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4354 if (!event_recorder_private_cache) {
4355 ret = -ENOMEM;
4356 goto error_kmem_event_recorder_private;
4357 }
4358 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4359 if (!event_notifier_cache) {
4360 ret = -ENOMEM;
4361 goto error_kmem_event_notifier;
4362 }
4363 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4364 if (!event_notifier_private_cache) {
4365 ret = -ENOMEM;
4366 goto error_kmem_event_notifier_private;
4367 }
4368 ret = lttng_abi_init();
4369 if (ret)
4370 goto error_abi;
4371 ret = lttng_logger_init();
4372 if (ret)
4373 goto error_logger;
4374 ret = lttng_init_cpu_hotplug();
4375 if (ret)
4376 goto error_hotplug;
4377 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4378 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4379 __stringify(LTTNG_MODULES_MINOR_VERSION),
4380 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4381 LTTNG_MODULES_EXTRAVERSION,
4382 LTTNG_VERSION_NAME,
4383 #ifdef LTTNG_EXTRA_VERSION_GIT
4384 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4385 #else
4386 "",
4387 #endif
4388 #ifdef LTTNG_EXTRA_VERSION_NAME
4389 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4390 #else
4391 "");
4392 #endif
4393 #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
4394 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
4395 #endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
4396 return 0;
4397
4398 error_hotplug:
4399 lttng_logger_exit();
4400 error_logger:
4401 lttng_abi_exit();
4402 error_abi:
4403 kmem_cache_destroy(event_notifier_private_cache);
4404 error_kmem_event_notifier_private:
4405 kmem_cache_destroy(event_notifier_cache);
4406 error_kmem_event_notifier:
4407 kmem_cache_destroy(event_recorder_private_cache);
4408 error_kmem_event_recorder_private:
4409 kmem_cache_destroy(event_recorder_cache);
4410 error_kmem_event_recorder:
4411 lttng_tracepoint_exit();
4412 error_tp:
4413 lttng_context_exit();
4414 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4415 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4416 __stringify(LTTNG_MODULES_MINOR_VERSION),
4417 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4418 LTTNG_MODULES_EXTRAVERSION,
4419 LTTNG_VERSION_NAME,
4420 #ifdef LTTNG_EXTRA_VERSION_GIT
4421 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4422 #else
4423 "",
4424 #endif
4425 #ifdef LTTNG_EXTRA_VERSION_NAME
4426 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4427 #else
4428 "");
4429 #endif
4430 return ret;
4431 }
4432
4433 module_init(lttng_events_init);
4434
4435 static void __exit lttng_events_exit(void)
4436 {
4437 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4438
4439 lttng_exit_cpu_hotplug();
4440 lttng_logger_exit();
4441 lttng_abi_exit();
4442 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4443 lttng_session_destroy(session_priv->pub);
4444 kmem_cache_destroy(event_recorder_cache);
4445 kmem_cache_destroy(event_recorder_private_cache);
4446 kmem_cache_destroy(event_notifier_cache);
4447 kmem_cache_destroy(event_notifier_private_cache);
4448 lttng_tracepoint_exit();
4449 lttng_context_exit();
4450 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4451 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4452 __stringify(LTTNG_MODULES_MINOR_VERSION),
4453 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4454 LTTNG_MODULES_EXTRAVERSION,
4455 LTTNG_VERSION_NAME,
4456 #ifdef LTTNG_EXTRA_VERSION_GIT
4457 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4458 #else
4459 "",
4460 #endif
4461 #ifdef LTTNG_EXTRA_VERSION_NAME
4462 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4463 #else
4464 "");
4465 #endif
4466 }
4467
4468 module_exit(lttng_events_exit);
4469
4470 #include <generated/patches.h>
4471 #ifdef LTTNG_EXTRA_VERSION_GIT
4472 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4473 #endif
4474 #ifdef LTTNG_EXTRA_VERSION_NAME
4475 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4476 #endif
4477 MODULE_LICENSE("GPL and additional rights");
4478 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4479 MODULE_DESCRIPTION("LTTng tracer");
4480 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4481 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4482 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4483 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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