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