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