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