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