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Refactoring: introduce lttng_kernel_event_notifier_clear_error_counter
[lttng-modules.git] / src / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
2 *
3 * lttng-events.c
4 *
5 * Holds LTTng per-session event registry.
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10 /*
11 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
12 * overrides a function with a define.
13 */
14 #include "wrapper/page_alloc.h"
15
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/jiffies.h>
21 #include <linux/utsname.h>
22 #include <linux/err.h>
23 #include <linux/seq_file.h>
24 #include <linux/file.h>
25 #include <linux/anon_inodes.h>
26 #include <wrapper/file.h>
27 #include <linux/uaccess.h>
28 #include <linux/vmalloc.h>
29 #include <linux/dmi.h>
30
31 #include <wrapper/compiler_attributes.h>
32 #include <wrapper/uuid.h>
33 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
34 #include <wrapper/random.h>
35 #include <wrapper/tracepoint.h>
36 #include <wrapper/list.h>
37 #include <wrapper/types.h>
38 #include <lttng/kernel-version.h>
39 #include <lttng/events.h>
40 #include <lttng/events-internal.h>
41 #include <lttng/lttng-bytecode.h>
42 #include <lttng/tracer.h>
43 #include <lttng/event-notifier-notification.h>
44 #include <lttng/abi-old.h>
45 #include <lttng/endian.h>
46 #include <lttng/string-utils.h>
47 #include <lttng/utils.h>
48 #include <ringbuffer/backend.h>
49 #include <ringbuffer/frontend.h>
50 #include <wrapper/time.h>
51
52 #define METADATA_CACHE_DEFAULT_SIZE 4096
53
54 static LIST_HEAD(sessions);
55 static LIST_HEAD(event_notifier_groups);
56 static LIST_HEAD(lttng_transport_list);
57 static LIST_HEAD(lttng_counter_transport_list);
58 /*
59 * Protect the sessions and metadata caches.
60 */
61 static DEFINE_MUTEX(sessions_mutex);
62 static struct kmem_cache *event_recorder_cache;
63 static struct kmem_cache *event_recorder_private_cache;
64 static struct kmem_cache *event_notifier_cache;
65 static struct kmem_cache *event_notifier_private_cache;
66
67 static void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session);
68 static void lttng_session_sync_event_enablers(struct lttng_kernel_session *session);
69 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
70 static void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler);
71
72 static void _lttng_event_destroy(struct lttng_kernel_event_common *event);
73 static void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan);
74 static int _lttng_event_unregister(struct lttng_kernel_event_common *event);
75 static
76 int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
77 struct lttng_kernel_channel_buffer *chan,
78 struct lttng_kernel_event_recorder *event);
79 static
80 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session);
81 static
82 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
83 static
84 int _lttng_type_statedump(struct lttng_kernel_session *session,
85 const struct lttng_kernel_type_common *type,
86 enum lttng_kernel_string_encoding parent_encoding,
87 size_t nesting);
88 static
89 int _lttng_field_statedump(struct lttng_kernel_session *session,
90 const struct lttng_kernel_event_field *field,
91 size_t nesting, const char **prev_field_name_p);
92
93 void synchronize_trace(void)
94 {
95 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0) || \
96 LTTNG_RHEL_KERNEL_RANGE(4,18,0,193,0,0, 4,19,0,0,0,0))
97 synchronize_rcu();
98 #else
99 synchronize_sched();
100 #endif
101
102 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
103 #ifdef CONFIG_PREEMPT_RT_FULL
104 synchronize_rcu();
105 #endif
106 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
107 #ifdef CONFIG_PREEMPT_RT
108 synchronize_rcu();
109 #endif
110 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
111 }
112
113 void lttng_lock_sessions(void)
114 {
115 mutex_lock(&sessions_mutex);
116 }
117
118 void lttng_unlock_sessions(void)
119 {
120 mutex_unlock(&sessions_mutex);
121 }
122
123 static struct lttng_transport *lttng_transport_find(const char *name)
124 {
125 struct lttng_transport *transport;
126
127 list_for_each_entry(transport, &lttng_transport_list, node) {
128 if (!strcmp(transport->name, name))
129 return transport;
130 }
131 return NULL;
132 }
133
134 /*
135 * Called with sessions lock held.
136 */
137 int lttng_session_active(void)
138 {
139 struct lttng_kernel_session_private *iter;
140
141 list_for_each_entry(iter, &sessions, list) {
142 if (iter->pub->active)
143 return 1;
144 }
145 return 0;
146 }
147
148 struct lttng_kernel_session *lttng_session_create(void)
149 {
150 struct lttng_kernel_session *session;
151 struct lttng_kernel_session_private *session_priv;
152 struct lttng_metadata_cache *metadata_cache;
153 int i;
154
155 mutex_lock(&sessions_mutex);
156 session = lttng_kvzalloc(sizeof(*session), GFP_KERNEL);
157 if (!session)
158 goto err;
159 session_priv = lttng_kvzalloc(sizeof(*session_priv), GFP_KERNEL);
160 if (!session_priv)
161 goto err_free_session;
162 session->priv = session_priv;
163 session_priv->pub = session;
164
165 INIT_LIST_HEAD(&session_priv->chan);
166 INIT_LIST_HEAD(&session_priv->events);
167 lttng_guid_gen(&session_priv->uuid);
168
169 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
170 GFP_KERNEL);
171 if (!metadata_cache)
172 goto err_free_session_private;
173 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
174 if (!metadata_cache->data)
175 goto err_free_cache;
176 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
177 kref_init(&metadata_cache->refcount);
178 mutex_init(&metadata_cache->lock);
179 session_priv->metadata_cache = metadata_cache;
180 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
181 memcpy(&metadata_cache->uuid, &session_priv->uuid,
182 sizeof(metadata_cache->uuid));
183 INIT_LIST_HEAD(&session_priv->enablers_head);
184 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
185 INIT_HLIST_HEAD(&session_priv->events_ht.table[i]);
186 list_add(&session_priv->list, &sessions);
187
188 if (lttng_id_tracker_init(&session->pid_tracker, session, TRACKER_PID))
189 goto tracker_alloc_error;
190 if (lttng_id_tracker_init(&session->vpid_tracker, session, TRACKER_VPID))
191 goto tracker_alloc_error;
192 if (lttng_id_tracker_init(&session->uid_tracker, session, TRACKER_UID))
193 goto tracker_alloc_error;
194 if (lttng_id_tracker_init(&session->vuid_tracker, session, TRACKER_VUID))
195 goto tracker_alloc_error;
196 if (lttng_id_tracker_init(&session->gid_tracker, session, TRACKER_GID))
197 goto tracker_alloc_error;
198 if (lttng_id_tracker_init(&session->vgid_tracker, session, TRACKER_VGID))
199 goto tracker_alloc_error;
200
201 mutex_unlock(&sessions_mutex);
202
203 return session;
204
205 tracker_alloc_error:
206 lttng_id_tracker_fini(&session->pid_tracker);
207 lttng_id_tracker_fini(&session->vpid_tracker);
208 lttng_id_tracker_fini(&session->uid_tracker);
209 lttng_id_tracker_fini(&session->vuid_tracker);
210 lttng_id_tracker_fini(&session->gid_tracker);
211 lttng_id_tracker_fini(&session->vgid_tracker);
212 err_free_cache:
213 kfree(metadata_cache);
214 err_free_session_private:
215 lttng_kvfree(session_priv);
216 err_free_session:
217 lttng_kvfree(session);
218 err:
219 mutex_unlock(&sessions_mutex);
220 return NULL;
221 }
222
223 static
224 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
225 {
226 struct lttng_counter_transport *transport;
227
228 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
229 if (!strcmp(transport->name, name))
230 return transport;
231 }
232 return NULL;
233 }
234
235 struct lttng_counter *lttng_kernel_counter_create(
236 const char *counter_transport_name,
237 size_t number_dimensions, const size_t *dimensions_sizes)
238 {
239 struct lttng_counter *counter = NULL;
240 struct lttng_counter_transport *counter_transport = NULL;
241
242 counter_transport = lttng_counter_transport_find(counter_transport_name);
243 if (!counter_transport) {
244 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
245 counter_transport_name);
246 goto notransport;
247 }
248 if (!try_module_get(counter_transport->owner)) {
249 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
250 goto notransport;
251 }
252
253 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
254 if (!counter)
255 goto nomem;
256
257 /* Create event notifier error counter. */
258 counter->ops = &counter_transport->ops;
259 counter->transport = counter_transport;
260
261 counter->counter = counter->ops->counter_create(
262 number_dimensions, dimensions_sizes, 0);
263 if (!counter->counter) {
264 goto create_error;
265 }
266
267 return counter;
268
269 create_error:
270 lttng_kvfree(counter);
271 nomem:
272 if (counter_transport)
273 module_put(counter_transport->owner);
274 notransport:
275 return NULL;
276 }
277
278 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
279 {
280 struct lttng_transport *transport = NULL;
281 struct lttng_event_notifier_group *event_notifier_group;
282 const char *transport_name = "relay-event-notifier";
283 size_t subbuf_size = 4096; //TODO
284 size_t num_subbuf = 16; //TODO
285 unsigned int switch_timer_interval = 0;
286 unsigned int read_timer_interval = 0;
287 int i;
288
289 mutex_lock(&sessions_mutex);
290
291 transport = lttng_transport_find(transport_name);
292 if (!transport) {
293 printk(KERN_WARNING "LTTng: transport %s not found\n",
294 transport_name);
295 goto notransport;
296 }
297 if (!try_module_get(transport->owner)) {
298 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
299 transport_name);
300 goto notransport;
301 }
302
303 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
304 GFP_KERNEL);
305 if (!event_notifier_group)
306 goto nomem;
307
308 /*
309 * Initialize the ring buffer used to store event notifier
310 * notifications.
311 */
312 event_notifier_group->ops = &transport->ops;
313 event_notifier_group->chan = transport->ops.priv->channel_create(
314 transport_name, event_notifier_group, NULL,
315 subbuf_size, num_subbuf, switch_timer_interval,
316 read_timer_interval);
317 if (!event_notifier_group->chan)
318 goto create_error;
319
320 event_notifier_group->transport = transport;
321
322 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
323 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
324 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
325 INIT_HLIST_HEAD(&event_notifier_group->events_ht.table[i]);
326
327 list_add(&event_notifier_group->node, &event_notifier_groups);
328
329 mutex_unlock(&sessions_mutex);
330
331 return event_notifier_group;
332
333 create_error:
334 lttng_kvfree(event_notifier_group);
335 nomem:
336 if (transport)
337 module_put(transport->owner);
338 notransport:
339 mutex_unlock(&sessions_mutex);
340 return NULL;
341 }
342
343 void metadata_cache_destroy(struct kref *kref)
344 {
345 struct lttng_metadata_cache *cache =
346 container_of(kref, struct lttng_metadata_cache, refcount);
347 vfree(cache->data);
348 kfree(cache);
349 }
350
351 void lttng_session_destroy(struct lttng_kernel_session *session)
352 {
353 struct lttng_kernel_channel_buffer_private *chan_priv, *tmpchan_priv;
354 struct lttng_kernel_event_recorder_private *event_recorder_priv, *tmpevent_recorder_priv;
355 struct lttng_metadata_stream *metadata_stream;
356 struct lttng_event_enabler_common *event_enabler, *tmp_event_enabler;
357 int ret;
358
359 mutex_lock(&sessions_mutex);
360 WRITE_ONCE(session->active, 0);
361 list_for_each_entry(chan_priv, &session->priv->chan, node) {
362 ret = lttng_syscalls_unregister_syscall_table(&chan_priv->parent.syscall_table);
363 WARN_ON(ret);
364 }
365 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
366 ret = _lttng_event_unregister(&event_recorder_priv->pub->parent);
367 WARN_ON(ret);
368 }
369 synchronize_trace(); /* Wait for in-flight events to complete */
370 list_for_each_entry(chan_priv, &session->priv->chan, node) {
371 ret = lttng_syscalls_destroy_syscall_table(&chan_priv->parent.syscall_table);
372 WARN_ON(ret);
373 }
374 list_for_each_entry_safe(event_enabler, tmp_event_enabler, &session->priv->enablers_head, node)
375 lttng_event_enabler_destroy(event_enabler);
376 list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv, &session->priv->events, parent.node)
377 _lttng_event_destroy(&event_recorder_priv->pub->parent);
378 list_for_each_entry_safe(chan_priv, tmpchan_priv, &session->priv->chan, node) {
379 BUG_ON(chan_priv->channel_type == METADATA_CHANNEL);
380 _lttng_channel_destroy(chan_priv->pub);
381 }
382 mutex_lock(&session->priv->metadata_cache->lock);
383 list_for_each_entry(metadata_stream, &session->priv->metadata_cache->metadata_stream, list)
384 _lttng_metadata_channel_hangup(metadata_stream);
385 mutex_unlock(&session->priv->metadata_cache->lock);
386 lttng_id_tracker_fini(&session->pid_tracker);
387 lttng_id_tracker_fini(&session->vpid_tracker);
388 lttng_id_tracker_fini(&session->uid_tracker);
389 lttng_id_tracker_fini(&session->vuid_tracker);
390 lttng_id_tracker_fini(&session->gid_tracker);
391 lttng_id_tracker_fini(&session->vgid_tracker);
392 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
393 list_del(&session->priv->list);
394 mutex_unlock(&sessions_mutex);
395 lttng_kvfree(session->priv);
396 lttng_kvfree(session);
397 }
398
399 void lttng_event_notifier_group_destroy(
400 struct lttng_event_notifier_group *event_notifier_group)
401 {
402 struct lttng_event_enabler_common *event_enabler, *tmp_event_enabler;
403 struct lttng_kernel_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
404 int ret;
405
406 if (!event_notifier_group)
407 return;
408
409 mutex_lock(&sessions_mutex);
410
411 ret = lttng_syscalls_unregister_syscall_table(&event_notifier_group->syscall_table);
412 WARN_ON(ret);
413
414 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
415 &event_notifier_group->event_notifiers_head, parent.node) {
416 ret = _lttng_event_unregister(&event_notifier_priv->pub->parent);
417 WARN_ON(ret);
418 }
419
420 /* Wait for in-flight event notifier to complete */
421 synchronize_trace();
422
423 irq_work_sync(&event_notifier_group->wakeup_pending);
424
425 ret = lttng_syscalls_destroy_syscall_table(&event_notifier_group->syscall_table);
426 WARN_ON(ret);
427
428 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
429 &event_notifier_group->enablers_head, node)
430 lttng_event_enabler_destroy(event_enabler);
431
432 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
433 &event_notifier_group->event_notifiers_head, parent.node)
434 _lttng_event_destroy(&event_notifier_priv->pub->parent);
435
436 if (event_notifier_group->error_counter) {
437 struct lttng_counter *error_counter = event_notifier_group->error_counter;
438
439 error_counter->ops->counter_destroy(error_counter->counter);
440 module_put(error_counter->transport->owner);
441 lttng_kvfree(error_counter);
442 event_notifier_group->error_counter = NULL;
443 }
444
445 event_notifier_group->ops->priv->channel_destroy(event_notifier_group->chan);
446 module_put(event_notifier_group->transport->owner);
447 list_del(&event_notifier_group->node);
448
449 mutex_unlock(&sessions_mutex);
450 lttng_kvfree(event_notifier_group);
451 }
452
453 int lttng_session_statedump(struct lttng_kernel_session *session)
454 {
455 int ret;
456
457 mutex_lock(&sessions_mutex);
458 ret = lttng_statedump_start(session);
459 mutex_unlock(&sessions_mutex);
460 return ret;
461 }
462
463 int lttng_session_enable(struct lttng_kernel_session *session)
464 {
465 int ret = 0;
466 struct lttng_kernel_channel_buffer_private *chan_priv;
467
468 mutex_lock(&sessions_mutex);
469 if (session->active) {
470 ret = -EBUSY;
471 goto end;
472 }
473
474 /* Set transient enabler state to "enabled" */
475 session->priv->tstate = 1;
476
477 /* We need to sync enablers with session before activation. */
478 lttng_session_sync_event_enablers(session);
479
480 /*
481 * Snapshot the number of events per channel to know the type of header
482 * we need to use.
483 */
484 list_for_each_entry(chan_priv, &session->priv->chan, node) {
485 if (chan_priv->header_type)
486 continue; /* don't change it if session stop/restart */
487 if (chan_priv->free_event_id < 31)
488 chan_priv->header_type = 1; /* compact */
489 else
490 chan_priv->header_type = 2; /* large */
491 }
492
493 /* Clear each stream's quiescent state. */
494 list_for_each_entry(chan_priv, &session->priv->chan, node) {
495 if (chan_priv->channel_type != METADATA_CHANNEL)
496 lib_ring_buffer_clear_quiescent_channel(chan_priv->rb_chan);
497 }
498
499 WRITE_ONCE(session->active, 1);
500 WRITE_ONCE(session->priv->been_active, 1);
501 ret = _lttng_session_metadata_statedump(session);
502 if (ret) {
503 WRITE_ONCE(session->active, 0);
504 goto end;
505 }
506 ret = lttng_statedump_start(session);
507 if (ret)
508 WRITE_ONCE(session->active, 0);
509 end:
510 mutex_unlock(&sessions_mutex);
511 return ret;
512 }
513
514 int lttng_session_disable(struct lttng_kernel_session *session)
515 {
516 int ret = 0;
517 struct lttng_kernel_channel_buffer_private *chan_priv;
518
519 mutex_lock(&sessions_mutex);
520 if (!session->active) {
521 ret = -EBUSY;
522 goto end;
523 }
524 WRITE_ONCE(session->active, 0);
525
526 /* Set transient enabler state to "disabled" */
527 session->priv->tstate = 0;
528 lttng_session_sync_event_enablers(session);
529
530 /* Set each stream's quiescent state. */
531 list_for_each_entry(chan_priv, &session->priv->chan, node) {
532 if (chan_priv->channel_type != METADATA_CHANNEL)
533 lib_ring_buffer_set_quiescent_channel(chan_priv->rb_chan);
534 }
535 end:
536 mutex_unlock(&sessions_mutex);
537 return ret;
538 }
539
540 int lttng_session_metadata_regenerate(struct lttng_kernel_session *session)
541 {
542 int ret = 0;
543 struct lttng_kernel_channel_buffer_private *chan_priv;
544 struct lttng_kernel_event_recorder_private *event_recorder_priv;
545 struct lttng_metadata_cache *cache = session->priv->metadata_cache;
546 struct lttng_metadata_stream *stream;
547
548 mutex_lock(&sessions_mutex);
549 if (!session->active) {
550 ret = -EBUSY;
551 goto end;
552 }
553
554 mutex_lock(&cache->lock);
555 memset(cache->data, 0, cache->cache_alloc);
556 cache->metadata_written = 0;
557 cache->version++;
558 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list) {
559 stream->metadata_out = 0;
560 stream->metadata_in = 0;
561 }
562 mutex_unlock(&cache->lock);
563
564 session->priv->metadata_dumped = 0;
565 list_for_each_entry(chan_priv, &session->priv->chan, node) {
566 chan_priv->metadata_dumped = 0;
567 }
568
569 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
570 event_recorder_priv->metadata_dumped = 0;
571 }
572
573 ret = _lttng_session_metadata_statedump(session);
574
575 end:
576 mutex_unlock(&sessions_mutex);
577 return ret;
578 }
579
580 static
581 bool is_channel_buffer_metadata(struct lttng_kernel_channel_common *channel)
582 {
583 struct lttng_kernel_channel_buffer *chan_buf;
584
585 if (channel->type != LTTNG_KERNEL_CHANNEL_TYPE_BUFFER)
586 return false;
587 chan_buf = container_of(channel, struct lttng_kernel_channel_buffer, parent);
588 if (chan_buf->priv->channel_type == METADATA_CHANNEL)
589 return true;
590 return false;
591 }
592
593 int lttng_channel_enable(struct lttng_kernel_channel_common *channel)
594 {
595 int ret = 0;
596
597 mutex_lock(&sessions_mutex);
598 if (is_channel_buffer_metadata(channel)) {
599 ret = -EPERM;
600 goto end;
601 }
602 if (channel->enabled) {
603 ret = -EEXIST;
604 goto end;
605 }
606 /* Set transient enabler state to "enabled" */
607 channel->priv->tstate = 1;
608 lttng_session_sync_event_enablers(channel->session);
609 /* Set atomically the state to "enabled" */
610 WRITE_ONCE(channel->enabled, 1);
611 end:
612 mutex_unlock(&sessions_mutex);
613 return ret;
614 }
615
616 int lttng_channel_disable(struct lttng_kernel_channel_common *channel)
617 {
618 int ret = 0;
619
620 mutex_lock(&sessions_mutex);
621 if (is_channel_buffer_metadata(channel)) {
622 ret = -EPERM;
623 goto end;
624 }
625 if (!channel->enabled) {
626 ret = -EEXIST;
627 goto end;
628 }
629 /* Set atomically the state to "disabled" */
630 WRITE_ONCE(channel->enabled, 0);
631 /* Set transient enabler state to "enabled" */
632 channel->priv->tstate = 0;
633 lttng_session_sync_event_enablers(channel->session);
634 end:
635 mutex_unlock(&sessions_mutex);
636 return ret;
637 }
638
639 int lttng_event_enable(struct lttng_kernel_event_common *event)
640 {
641 int ret = 0;
642
643 mutex_lock(&sessions_mutex);
644 switch (event->type) {
645 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
646 {
647 struct lttng_kernel_event_recorder *event_recorder =
648 container_of(event, struct lttng_kernel_event_recorder, parent);
649
650 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
651 ret = -EPERM;
652 goto end;
653 }
654 break;
655 }
656 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
657 switch (event->priv->instrumentation) {
658 case LTTNG_KERNEL_ABI_KRETPROBE:
659 ret = -EINVAL;
660 goto end;
661 default:
662 break;
663 }
664 break;
665 default:
666 break;
667 }
668
669 if (event->enabled) {
670 ret = -EEXIST;
671 goto end;
672 }
673 switch (event->priv->instrumentation) {
674 case LTTNG_KERNEL_ABI_TRACEPOINT:
675 lttng_fallthrough;
676 case LTTNG_KERNEL_ABI_SYSCALL:
677 ret = -EINVAL;
678 break;
679
680 case LTTNG_KERNEL_ABI_KPROBE:
681 lttng_fallthrough;
682 case LTTNG_KERNEL_ABI_UPROBE:
683 WRITE_ONCE(event->enabled, 1);
684 break;
685
686 case LTTNG_KERNEL_ABI_KRETPROBE:
687 ret = lttng_kretprobes_event_enable_state(event, 1);
688 break;
689
690 case LTTNG_KERNEL_ABI_FUNCTION:
691 lttng_fallthrough;
692 case LTTNG_KERNEL_ABI_NOOP:
693 lttng_fallthrough;
694 default:
695 WARN_ON_ONCE(1);
696 ret = -EINVAL;
697 }
698 end:
699 mutex_unlock(&sessions_mutex);
700 return ret;
701 }
702
703 int lttng_event_disable(struct lttng_kernel_event_common *event)
704 {
705 int ret = 0;
706
707 mutex_lock(&sessions_mutex);
708 switch (event->type) {
709 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
710 {
711 struct lttng_kernel_event_recorder *event_recorder =
712 container_of(event, struct lttng_kernel_event_recorder, parent);
713
714 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
715 ret = -EPERM;
716 goto end;
717 }
718 break;
719 }
720 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
721 switch (event->priv->instrumentation) {
722 case LTTNG_KERNEL_ABI_KRETPROBE:
723 ret = -EINVAL;
724 goto end;
725 default:
726 break;
727 }
728 break;
729 default:
730 break;
731 }
732
733 if (!event->enabled) {
734 ret = -EEXIST;
735 goto end;
736 }
737 switch (event->priv->instrumentation) {
738 case LTTNG_KERNEL_ABI_TRACEPOINT:
739 lttng_fallthrough;
740 case LTTNG_KERNEL_ABI_SYSCALL:
741 ret = -EINVAL;
742 break;
743
744 case LTTNG_KERNEL_ABI_KPROBE:
745 lttng_fallthrough;
746 case LTTNG_KERNEL_ABI_UPROBE:
747 WRITE_ONCE(event->enabled, 0);
748 break;
749
750 case LTTNG_KERNEL_ABI_KRETPROBE:
751 ret = lttng_kretprobes_event_enable_state(event, 0);
752 break;
753
754 case LTTNG_KERNEL_ABI_FUNCTION:
755 lttng_fallthrough;
756 case LTTNG_KERNEL_ABI_NOOP:
757 lttng_fallthrough;
758 default:
759 WARN_ON_ONCE(1);
760 ret = -EINVAL;
761 }
762 end:
763 mutex_unlock(&sessions_mutex);
764 return ret;
765 }
766
767 struct lttng_kernel_channel_buffer *lttng_channel_buffer_create(struct lttng_kernel_session *session,
768 const char *transport_name,
769 void *buf_addr,
770 size_t subbuf_size, size_t num_subbuf,
771 unsigned int switch_timer_interval,
772 unsigned int read_timer_interval,
773 enum channel_type channel_type)
774 {
775 struct lttng_kernel_channel_buffer *chan;
776 struct lttng_kernel_channel_buffer_private *chan_priv;
777 struct lttng_transport *transport = NULL;
778
779 mutex_lock(&sessions_mutex);
780 if (session->priv->been_active && channel_type != METADATA_CHANNEL)
781 goto active; /* Refuse to add channel to active session */
782 transport = lttng_transport_find(transport_name);
783 if (!transport) {
784 printk(KERN_WARNING "LTTng: transport %s not found\n",
785 transport_name);
786 goto notransport;
787 }
788 if (!try_module_get(transport->owner)) {
789 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
790 goto notransport;
791 }
792 chan = kzalloc(sizeof(struct lttng_kernel_channel_buffer), GFP_KERNEL);
793 if (!chan)
794 goto nomem;
795 chan_priv = kzalloc(sizeof(struct lttng_kernel_channel_buffer_private), GFP_KERNEL);
796 if (!chan_priv)
797 goto nomem_priv;
798 chan->priv = chan_priv;
799 chan_priv->pub = chan;
800 chan->parent.type = LTTNG_KERNEL_CHANNEL_TYPE_BUFFER;
801 chan->parent.session = session;
802 chan->priv->id = session->priv->free_chan_id++;
803 chan->ops = &transport->ops;
804 /*
805 * Note: the channel creation op already writes into the packet
806 * headers. Therefore the "chan" information used as input
807 * should be already accessible.
808 */
809 chan->priv->rb_chan = transport->ops.priv->channel_create(transport_name,
810 chan, buf_addr, subbuf_size, num_subbuf,
811 switch_timer_interval, read_timer_interval);
812 if (!chan->priv->rb_chan)
813 goto create_error;
814 chan->priv->parent.tstate = 1;
815 chan->parent.enabled = 1;
816 chan->priv->transport = transport;
817 chan->priv->channel_type = channel_type;
818 list_add(&chan->priv->node, &session->priv->chan);
819 mutex_unlock(&sessions_mutex);
820 return chan;
821
822 create_error:
823 kfree(chan_priv);
824 nomem_priv:
825 kfree(chan);
826 nomem:
827 if (transport)
828 module_put(transport->owner);
829 notransport:
830 active:
831 mutex_unlock(&sessions_mutex);
832 return NULL;
833 }
834
835 /*
836 * Only used internally at session destruction for per-cpu channels, and
837 * when metadata channel is released.
838 * Needs to be called with sessions mutex held.
839 */
840 static
841 void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan)
842 {
843 chan->ops->priv->channel_destroy(chan->priv->rb_chan);
844 module_put(chan->priv->transport->owner);
845 list_del(&chan->priv->node);
846 lttng_kernel_destroy_context(chan->priv->ctx);
847 kfree(chan->priv);
848 kfree(chan);
849 }
850
851 void lttng_metadata_channel_destroy(struct lttng_kernel_channel_buffer *chan)
852 {
853 BUG_ON(chan->priv->channel_type != METADATA_CHANNEL);
854
855 /* Protect the metadata cache with the sessions_mutex. */
856 mutex_lock(&sessions_mutex);
857 _lttng_channel_destroy(chan);
858 mutex_unlock(&sessions_mutex);
859 }
860 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
861
862 static
863 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
864 {
865 stream->finalized = 1;
866 wake_up_interruptible(&stream->read_wait);
867 }
868
869 static
870 struct lttng_kernel_event_common *lttng_kernel_event_alloc(struct lttng_event_enabler_common *event_enabler)
871 {
872 struct lttng_kernel_abi_event *event_param = &event_enabler->event_param;
873 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
874
875 switch (event_enabler->enabler_type) {
876 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
877 {
878 struct lttng_event_recorder_enabler *event_recorder_enabler =
879 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
880 struct lttng_kernel_event_recorder *event_recorder;
881 struct lttng_kernel_event_recorder_private *event_recorder_priv;
882 struct lttng_kernel_channel_buffer *chan = event_recorder_enabler->chan;
883
884 event_recorder = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
885 if (!event_recorder)
886 return NULL;
887 event_recorder_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
888 if (!event_recorder_priv) {
889 kmem_cache_free(event_recorder_private_cache, event_recorder);
890 return NULL;
891 }
892 event_recorder_priv->pub = event_recorder;
893 event_recorder_priv->parent.pub = &event_recorder->parent;
894 event_recorder->priv = event_recorder_priv;
895 event_recorder->parent.priv = &event_recorder_priv->parent;
896
897 event_recorder->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
898 event_recorder->parent.run_filter = lttng_kernel_interpret_event_filter;
899 event_recorder->priv->parent.instrumentation = itype;
900 INIT_LIST_HEAD(&event_recorder->priv->parent.filter_bytecode_runtime_head);
901 INIT_LIST_HEAD(&event_recorder->priv->parent.enablers_ref_head);
902
903 event_recorder->chan = chan;
904 event_recorder->priv->id = chan->priv->free_event_id++;
905 return &event_recorder->parent;
906 }
907 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
908 {
909 struct lttng_event_notifier_enabler *event_notifier_enabler =
910 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
911 struct lttng_kernel_event_notifier *event_notifier;
912 struct lttng_kernel_event_notifier_private *event_notifier_priv;
913
914 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
915 if (!event_notifier)
916 return NULL;
917 event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
918 if (!event_notifier_priv) {
919 kmem_cache_free(event_notifier_private_cache, event_notifier);
920 return NULL;
921 }
922 event_notifier_priv->pub = event_notifier;
923 event_notifier_priv->parent.pub = &event_notifier->parent;
924 event_notifier->priv = event_notifier_priv;
925 event_notifier->parent.priv = &event_notifier_priv->parent;
926
927 event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
928 event_notifier->parent.run_filter = lttng_kernel_interpret_event_filter;
929 event_notifier->priv->parent.instrumentation = itype;
930 event_notifier->priv->parent.user_token = event_enabler->user_token;
931 INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
932 INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
933
934 event_notifier->priv->group = event_notifier_enabler->group;
935 event_notifier->priv->error_counter_index = event_notifier_enabler->error_counter_index;
936 event_notifier->priv->num_captures = 0;
937 event_notifier->notification_send = lttng_event_notifier_notification_send;
938 INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
939 return &event_notifier->parent;
940 }
941 default:
942 return NULL;
943 }
944 }
945
946 static
947 void lttng_kernel_event_free(struct lttng_kernel_event_common *event)
948 {
949 switch (event->type) {
950 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
951 {
952 struct lttng_kernel_event_recorder *event_recorder =
953 container_of(event, struct lttng_kernel_event_recorder, parent);
954
955 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
956 kmem_cache_free(event_recorder_cache, event_recorder);
957 break;
958 }
959 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
960 {
961 struct lttng_kernel_event_notifier *event_notifier =
962 container_of(event, struct lttng_kernel_event_notifier, parent);
963
964 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
965 kmem_cache_free(event_notifier_cache, event_notifier);
966 break;
967 }
968 default:
969 WARN_ON_ONCE(1);
970 }
971 }
972
973 static
974 int lttng_kernel_event_notifier_clear_error_counter(struct lttng_kernel_event_common *event)
975 {
976 switch (event->type) {
977 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
978 return 0;
979 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
980 {
981 struct lttng_kernel_event_notifier *event_notifier =
982 container_of(event, struct lttng_kernel_event_notifier, parent);
983 struct lttng_counter *error_counter;
984 struct lttng_event_notifier_group *event_notifier_group = event_notifier->priv->group;
985 size_t dimension_index[1];
986 int ret;
987
988 /*
989 * Clear the error counter bucket. The sessiond keeps track of which
990 * bucket is currently in use. We trust it. The session lock
991 * synchronizes against concurrent creation of the error
992 * counter.
993 */
994 error_counter = event_notifier_group->error_counter;
995 if (!error_counter)
996 return 0;
997 /*
998 * Check that the index is within the boundary of the counter.
999 */
1000 if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
1001 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1002 event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
1003 return -EINVAL;
1004 }
1005
1006 dimension_index[0] = event_notifier->priv->error_counter_index;
1007 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1008 if (ret) {
1009 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1010 event_notifier->priv->error_counter_index);
1011 return -EINVAL;
1012 }
1013 return 0;
1014 }
1015 default:
1016 return -EINVAL;
1017 }
1018 }
1019
1020 /*
1021 * Supports event creation while tracing session is active.
1022 * Needs to be called with sessions mutex held.
1023 */
1024 static
1025 struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_event_recorder_enabler *event_enabler,
1026 const struct lttng_kernel_event_desc *event_desc)
1027 {
1028 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_enabler->parent);
1029 struct lttng_kernel_channel_buffer *chan = event_enabler->chan;
1030 struct lttng_kernel_abi_event *event_param = &event_enabler->parent.event_param;
1031 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
1032 struct lttng_kernel_event_common_private *event_priv;
1033 struct lttng_kernel_event_common *event;
1034 struct lttng_kernel_event_recorder *event_recorder;
1035 const char *event_name;
1036 struct hlist_head *head;
1037 int ret;
1038
1039 if (chan->priv->free_event_id == -1U) {
1040 ret = -EMFILE;
1041 goto full;
1042 }
1043
1044 switch (itype) {
1045 case LTTNG_KERNEL_ABI_TRACEPOINT:
1046 event_name = event_desc->event_name;
1047 break;
1048
1049 case LTTNG_KERNEL_ABI_KPROBE:
1050 lttng_fallthrough;
1051 case LTTNG_KERNEL_ABI_UPROBE:
1052 lttng_fallthrough;
1053 case LTTNG_KERNEL_ABI_KRETPROBE:
1054 lttng_fallthrough;
1055 case LTTNG_KERNEL_ABI_SYSCALL:
1056 event_name = event_param->name;
1057 break;
1058
1059 case LTTNG_KERNEL_ABI_FUNCTION:
1060 lttng_fallthrough;
1061 case LTTNG_KERNEL_ABI_NOOP:
1062 lttng_fallthrough;
1063 default:
1064 WARN_ON_ONCE(1);
1065 ret = -EINVAL;
1066 goto type_error;
1067 }
1068
1069 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, event_name);
1070 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
1071 if (lttng_event_enabler_event_name_match_event(&event_enabler->parent, event_name, event_priv->pub)) {
1072 ret = -EEXIST;
1073 goto exist;
1074 }
1075 }
1076
1077 event = lttng_kernel_event_alloc(&event_enabler->parent);
1078 if (!event) {
1079 ret = -ENOMEM;
1080 goto alloc_error;
1081 }
1082 event_recorder = container_of(event, struct lttng_kernel_event_recorder, parent);
1083
1084 switch (itype) {
1085 case LTTNG_KERNEL_ABI_TRACEPOINT:
1086 /* Event will be enabled by enabler sync. */
1087 event->enabled = 0;
1088 event->priv->registered = 0;
1089 event->priv->desc = lttng_event_desc_get(event_name);
1090 if (!event->priv->desc) {
1091 ret = -ENOENT;
1092 goto register_error;
1093 }
1094 /* Populate lttng_event structure before event registration. */
1095 smp_wmb();
1096 break;
1097
1098 case LTTNG_KERNEL_ABI_KPROBE:
1099 /*
1100 * Needs to be explicitly enabled after creation, since
1101 * we may want to apply filters.
1102 */
1103 event->enabled = 0;
1104 event->priv->registered = 1;
1105 /*
1106 * Populate lttng_event structure before event
1107 * registration.
1108 */
1109 smp_wmb();
1110 ret = lttng_kprobes_register_event(event_name,
1111 event_param->u.kprobe.symbol_name,
1112 event_param->u.kprobe.offset,
1113 event_param->u.kprobe.addr,
1114 event);
1115 if (ret) {
1116 ret = -EINVAL;
1117 goto register_error;
1118 }
1119 ret = try_module_get(event->priv->desc->owner);
1120 WARN_ON_ONCE(!ret);
1121 break;
1122
1123 case LTTNG_KERNEL_ABI_KRETPROBE:
1124 {
1125 struct lttng_kernel_event_common *event_return;
1126 struct lttng_kernel_event_recorder *event_recorder_return;
1127
1128 /* kretprobe defines 2 events */
1129 /*
1130 * Needs to be explicitly enabled after creation, since
1131 * we may want to apply filters.
1132 */
1133 event->enabled = 0;
1134 event->priv->registered = 1;
1135
1136 event_return = lttng_kernel_event_alloc(&event_enabler->parent);
1137 if (!event) {
1138 ret = -ENOMEM;
1139 goto alloc_error;
1140 }
1141 event_recorder_return = container_of(event_return, struct lttng_kernel_event_recorder, parent);
1142
1143 event_return->enabled = 0;
1144 event_return->priv->registered = 1;
1145
1146 /*
1147 * Populate lttng_event structure before kretprobe registration.
1148 */
1149 smp_wmb();
1150 ret = lttng_kretprobes_register(event_name,
1151 event_param->u.kretprobe.symbol_name,
1152 event_param->u.kretprobe.offset,
1153 event_param->u.kretprobe.addr,
1154 event, event_return);
1155 if (ret) {
1156 lttng_kernel_event_free(event_return);
1157 ret = -EINVAL;
1158 goto register_error;
1159 }
1160 /* Take 2 refs on the module: one per event. */
1161 ret = try_module_get(event->priv->desc->owner);
1162 WARN_ON_ONCE(!ret);
1163 ret = try_module_get(event_return->priv->desc->owner);
1164 WARN_ON_ONCE(!ret);
1165 ret = _lttng_event_metadata_statedump(chan->parent.session, chan, event_recorder_return);
1166 WARN_ON_ONCE(ret > 0);
1167 if (ret) {
1168 lttng_kernel_event_free(event_return);
1169 module_put(event_return->priv->desc->owner);
1170 module_put(event->priv->desc->owner);
1171 goto statedump_error;
1172 }
1173 list_add(&event_return->priv->node, &chan->parent.session->priv->events);
1174 break;
1175 }
1176
1177 case LTTNG_KERNEL_ABI_SYSCALL:
1178 /*
1179 * Needs to be explicitly enabled after creation, since
1180 * we may want to apply filters.
1181 */
1182 event->enabled = 0;
1183 event->priv->registered = 0;
1184 event->priv->desc = event_desc;
1185 switch (event_param->u.syscall.entryexit) {
1186 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1187 ret = -EINVAL;
1188 goto register_error;
1189 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1190 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1191 break;
1192 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1193 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1194 break;
1195 }
1196 switch (event_param->u.syscall.abi) {
1197 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1198 ret = -EINVAL;
1199 goto register_error;
1200 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1201 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1202 break;
1203 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1204 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1205 break;
1206 }
1207 if (!event->priv->desc) {
1208 ret = -EINVAL;
1209 goto register_error;
1210 }
1211 break;
1212
1213 case LTTNG_KERNEL_ABI_UPROBE:
1214 /*
1215 * Needs to be explicitly enabled after creation, since
1216 * we may want to apply filters.
1217 */
1218 event->enabled = 0;
1219 event->priv->registered = 1;
1220
1221 /*
1222 * Populate lttng_event structure before event
1223 * registration.
1224 */
1225 smp_wmb();
1226
1227 ret = lttng_uprobes_register_event(event_param->name,
1228 event_param->u.uprobe.fd,
1229 event);
1230 if (ret)
1231 goto register_error;
1232 ret = try_module_get(event->priv->desc->owner);
1233 WARN_ON_ONCE(!ret);
1234 break;
1235
1236 case LTTNG_KERNEL_ABI_FUNCTION:
1237 lttng_fallthrough;
1238 case LTTNG_KERNEL_ABI_NOOP:
1239 lttng_fallthrough;
1240 default:
1241 WARN_ON_ONCE(1);
1242 ret = -EINVAL;
1243 goto register_error;
1244 }
1245 ret = _lttng_event_metadata_statedump(chan->parent.session, chan, event_recorder);
1246 WARN_ON_ONCE(ret > 0);
1247 if (ret) {
1248 goto statedump_error;
1249 }
1250 hlist_add_head(&event->priv->hlist_node, head);
1251 list_add(&event->priv->node, &chan->parent.session->priv->events);
1252 return event_recorder;
1253
1254 statedump_error:
1255 /* If a statedump error occurs, events will not be readable. */
1256 register_error:
1257 lttng_kernel_event_free(event);
1258 alloc_error:
1259 exist:
1260 type_error:
1261 full:
1262 return ERR_PTR(ret);
1263 }
1264
1265 static
1266 struct lttng_kernel_event_notifier *_lttng_kernel_event_notifier_create(struct lttng_event_notifier_enabler *event_enabler,
1267 const struct lttng_kernel_event_desc *event_desc)
1268 {
1269 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_enabler->parent);
1270 struct lttng_event_notifier_group *event_notifier_group = event_enabler->group;
1271 struct lttng_kernel_abi_event *event_param = &event_enabler->parent.event_param;
1272 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
1273 struct lttng_kernel_event_common_private *event_priv;
1274 struct lttng_kernel_event_common *event;
1275 struct lttng_kernel_event_notifier *event_notifier;
1276 const char *event_name;
1277 struct hlist_head *head;
1278 int ret;
1279
1280 switch (itype) {
1281 case LTTNG_KERNEL_ABI_TRACEPOINT:
1282 event_name = event_desc->event_name;
1283 break;
1284
1285 case LTTNG_KERNEL_ABI_KPROBE:
1286 lttng_fallthrough;
1287 case LTTNG_KERNEL_ABI_UPROBE:
1288 lttng_fallthrough;
1289 case LTTNG_KERNEL_ABI_SYSCALL:
1290 event_name = event_param->name;
1291 break;
1292
1293 case LTTNG_KERNEL_ABI_KRETPROBE:
1294 lttng_fallthrough;
1295 case LTTNG_KERNEL_ABI_FUNCTION:
1296 lttng_fallthrough;
1297 case LTTNG_KERNEL_ABI_NOOP:
1298 lttng_fallthrough;
1299 default:
1300 WARN_ON_ONCE(1);
1301 ret = -EINVAL;
1302 goto type_error;
1303 }
1304
1305 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, event_name);
1306 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
1307 if (lttng_event_enabler_event_name_match_event(&event_enabler->parent, event_name, event_priv->pub)) {
1308 ret = -EEXIST;
1309 goto exist;
1310 }
1311 }
1312
1313 event = lttng_kernel_event_alloc(&event_enabler->parent);
1314 if (!event) {
1315 ret = -ENOMEM;
1316 goto alloc_error;
1317 }
1318 event_notifier = container_of(event, struct lttng_kernel_event_notifier, parent);
1319
1320 switch (itype) {
1321 case LTTNG_KERNEL_ABI_TRACEPOINT:
1322 /* Event will be enabled by enabler sync. */
1323 event->enabled = 0;
1324 event->priv->registered = 0;
1325 event->priv->desc = lttng_event_desc_get(event_name);
1326 if (!event->priv->desc) {
1327 ret = -ENOENT;
1328 goto register_error;
1329 }
1330 /* Populate lttng_event_notifier structure before event registration. */
1331 smp_wmb();
1332 break;
1333
1334 case LTTNG_KERNEL_ABI_KPROBE:
1335 /*
1336 * Needs to be explicitly enabled after creation, since
1337 * we may want to apply filters.
1338 */
1339 event->enabled = 0;
1340 event->priv->registered = 1;
1341 /*
1342 * Populate lttng_event_notifier structure before event
1343 * registration.
1344 */
1345 smp_wmb();
1346 ret = lttng_kprobes_register_event(event_param->u.kprobe.symbol_name,
1347 event_param->u.kprobe.symbol_name,
1348 event_param->u.kprobe.offset,
1349 event_param->u.kprobe.addr,
1350 event);
1351 if (ret) {
1352 ret = -EINVAL;
1353 goto register_error;
1354 }
1355 ret = try_module_get(event->priv->desc->owner);
1356 WARN_ON_ONCE(!ret);
1357 break;
1358
1359 case LTTNG_KERNEL_ABI_SYSCALL:
1360 /*
1361 * Needs to be explicitly enabled after creation, since
1362 * we may want to apply filters.
1363 */
1364 event->enabled = 0;
1365 event->priv->registered = 0;
1366 event->priv->desc = event_desc;
1367 switch (event_param->u.syscall.entryexit) {
1368 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1369 ret = -EINVAL;
1370 goto register_error;
1371 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1372 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1373 break;
1374 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1375 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1376 break;
1377 }
1378 switch (event_param->u.syscall.abi) {
1379 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1380 ret = -EINVAL;
1381 goto register_error;
1382 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1383 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1384 break;
1385 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1386 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1387 break;
1388 }
1389
1390 if (!event->priv->desc) {
1391 ret = -EINVAL;
1392 goto register_error;
1393 }
1394 break;
1395
1396 case LTTNG_KERNEL_ABI_UPROBE:
1397 /*
1398 * Needs to be explicitly enabled after creation, since
1399 * we may want to apply filters.
1400 */
1401 event->enabled = 0;
1402 event->priv->registered = 1;
1403
1404 /*
1405 * Populate lttng_event_notifier structure before
1406 * event_notifier registration.
1407 */
1408 smp_wmb();
1409
1410 ret = lttng_uprobes_register_event(event_param->name,
1411 event_param->u.uprobe.fd,
1412 event);
1413 if (ret)
1414 goto register_error;
1415 ret = try_module_get(event->priv->desc->owner);
1416 WARN_ON_ONCE(!ret);
1417 break;
1418
1419 case LTTNG_KERNEL_ABI_KRETPROBE:
1420 lttng_fallthrough;
1421 case LTTNG_KERNEL_ABI_FUNCTION:
1422 lttng_fallthrough;
1423 case LTTNG_KERNEL_ABI_NOOP:
1424 lttng_fallthrough;
1425 default:
1426 WARN_ON_ONCE(1);
1427 ret = -EINVAL;
1428 goto register_error;
1429 }
1430
1431 list_add(&event->priv->node, &event_notifier_group->event_notifiers_head);
1432 hlist_add_head(&event->priv->hlist_node, head);
1433
1434 ret = lttng_kernel_event_notifier_clear_error_counter(event);
1435 if (ret)
1436 goto register_error;
1437 return event_notifier;
1438
1439 register_error:
1440 lttng_kernel_event_free(event);
1441 alloc_error:
1442 exist:
1443 type_error:
1444 return ERR_PTR(ret);
1445 }
1446
1447 struct lttng_kernel_event_common *_lttng_kernel_event_create(struct lttng_event_enabler_common *event_enabler,
1448 const struct lttng_kernel_event_desc *event_desc)
1449 {
1450 switch (event_enabler->enabler_type) {
1451 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
1452 {
1453 struct lttng_event_recorder_enabler *event_recorder_enabler =
1454 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
1455 struct lttng_kernel_event_recorder *event_recorder;
1456
1457 event_recorder = _lttng_kernel_event_recorder_create(event_recorder_enabler, event_desc);
1458 if (!event_recorder)
1459 return NULL;
1460 return &event_recorder->parent;
1461 }
1462 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
1463 {
1464 struct lttng_event_notifier_enabler *event_notifier_enabler =
1465 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
1466 struct lttng_kernel_event_notifier *event_notifier;
1467
1468 event_notifier = _lttng_kernel_event_notifier_create(event_notifier_enabler, event_desc);
1469 if (!event_notifier)
1470 return NULL;
1471 return &event_notifier->parent;
1472 }
1473 default:
1474 return NULL;
1475 }
1476 }
1477
1478 struct lttng_kernel_event_common *lttng_kernel_event_create(struct lttng_event_enabler_common *event_enabler,
1479 const struct lttng_kernel_event_desc *event_desc)
1480 {
1481 struct lttng_kernel_event_common *event;
1482
1483 mutex_lock(&sessions_mutex);
1484 event = _lttng_kernel_event_create(event_enabler, event_desc);
1485 mutex_unlock(&sessions_mutex);
1486 return event;
1487 }
1488
1489
1490
1491 int lttng_kernel_counter_read(struct lttng_counter *counter,
1492 const size_t *dim_indexes, int32_t cpu,
1493 int64_t *val, bool *overflow, bool *underflow)
1494 {
1495 return counter->ops->counter_read(counter->counter, dim_indexes,
1496 cpu, val, overflow, underflow);
1497 }
1498
1499 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1500 const size_t *dim_indexes, int64_t *val,
1501 bool *overflow, bool *underflow)
1502 {
1503 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1504 val, overflow, underflow);
1505 }
1506
1507 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1508 const size_t *dim_indexes)
1509 {
1510 return counter->ops->counter_clear(counter->counter, dim_indexes);
1511 }
1512
1513 /* Only used for tracepoints for now. */
1514 static
1515 void register_event(struct lttng_kernel_event_common *event)
1516 {
1517 const struct lttng_kernel_event_desc *desc;
1518 int ret = -EINVAL;
1519
1520 if (event->priv->registered)
1521 return;
1522
1523 desc = event->priv->desc;
1524 switch (event->priv->instrumentation) {
1525 case LTTNG_KERNEL_ABI_TRACEPOINT:
1526 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1527 desc->tp_class->probe_callback,
1528 event);
1529 break;
1530
1531 case LTTNG_KERNEL_ABI_SYSCALL:
1532 ret = lttng_syscall_filter_enable_event(event);
1533 break;
1534
1535 case LTTNG_KERNEL_ABI_KPROBE:
1536 lttng_fallthrough;
1537 case LTTNG_KERNEL_ABI_UPROBE:
1538 ret = 0;
1539 break;
1540
1541 case LTTNG_KERNEL_ABI_KRETPROBE:
1542 switch (event->type) {
1543 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1544 ret = 0;
1545 break;
1546 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1547 WARN_ON_ONCE(1);
1548 break;
1549 }
1550 break;
1551
1552 case LTTNG_KERNEL_ABI_FUNCTION:
1553 lttng_fallthrough;
1554 case LTTNG_KERNEL_ABI_NOOP:
1555 lttng_fallthrough;
1556 default:
1557 WARN_ON_ONCE(1);
1558 }
1559 if (!ret)
1560 event->priv->registered = 1;
1561 }
1562
1563 int _lttng_event_unregister(struct lttng_kernel_event_common *event)
1564 {
1565 struct lttng_kernel_event_common_private *event_priv = event->priv;
1566 const struct lttng_kernel_event_desc *desc;
1567 int ret = -EINVAL;
1568
1569 if (!event_priv->registered)
1570 return 0;
1571
1572 desc = event_priv->desc;
1573 switch (event_priv->instrumentation) {
1574 case LTTNG_KERNEL_ABI_TRACEPOINT:
1575 ret = lttng_wrapper_tracepoint_probe_unregister(event_priv->desc->event_kname,
1576 event_priv->desc->tp_class->probe_callback,
1577 event);
1578 break;
1579
1580 case LTTNG_KERNEL_ABI_KPROBE:
1581 lttng_kprobes_unregister_event(event);
1582 ret = 0;
1583 break;
1584
1585 case LTTNG_KERNEL_ABI_KRETPROBE:
1586 switch (event->type) {
1587 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1588 lttng_kretprobes_unregister(event);
1589 ret = 0;
1590 break;
1591 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1592 WARN_ON_ONCE(1);
1593 break;
1594 }
1595 break;
1596
1597 case LTTNG_KERNEL_ABI_SYSCALL:
1598 ret = lttng_syscall_filter_disable_event(event);
1599 break;
1600
1601 case LTTNG_KERNEL_ABI_NOOP:
1602 switch (event->type) {
1603 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1604 ret = 0;
1605 break;
1606 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1607 WARN_ON_ONCE(1);
1608 break;
1609 }
1610 break;
1611
1612 case LTTNG_KERNEL_ABI_UPROBE:
1613 lttng_uprobes_unregister_event(event);
1614 ret = 0;
1615 break;
1616
1617 case LTTNG_KERNEL_ABI_FUNCTION:
1618 lttng_fallthrough;
1619 default:
1620 WARN_ON_ONCE(1);
1621 }
1622 if (!ret)
1623 event_priv->registered = 0;
1624 return ret;
1625 }
1626
1627 /*
1628 * Only used internally at session destruction.
1629 */
1630 static
1631 void _lttng_event_destroy(struct lttng_kernel_event_common *event)
1632 {
1633 struct lttng_kernel_event_common_private *event_priv = event->priv;
1634 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1635
1636 lttng_free_event_filter_runtime(event);
1637 /* Free event enabler refs */
1638 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1639 &event_priv->enablers_ref_head, node)
1640 kfree(enabler_ref);
1641
1642 switch (event->type) {
1643 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1644 {
1645 struct lttng_kernel_event_recorder *event_recorder =
1646 container_of(event, struct lttng_kernel_event_recorder, parent);
1647
1648 switch (event_priv->instrumentation) {
1649 case LTTNG_KERNEL_ABI_TRACEPOINT:
1650 lttng_event_desc_put(event_priv->desc);
1651 break;
1652
1653 case LTTNG_KERNEL_ABI_KPROBE:
1654 module_put(event_priv->desc->owner);
1655 lttng_kprobes_destroy_event_private(&event_recorder->parent);
1656 break;
1657
1658 case LTTNG_KERNEL_ABI_KRETPROBE:
1659 module_put(event_priv->desc->owner);
1660 lttng_kretprobes_destroy_private(&event_recorder->parent);
1661 break;
1662
1663 case LTTNG_KERNEL_ABI_SYSCALL:
1664 break;
1665
1666 case LTTNG_KERNEL_ABI_UPROBE:
1667 module_put(event_priv->desc->owner);
1668 lttng_uprobes_destroy_event_private(&event_recorder->parent);
1669 break;
1670
1671 case LTTNG_KERNEL_ABI_FUNCTION:
1672 lttng_fallthrough;
1673 case LTTNG_KERNEL_ABI_NOOP:
1674 lttng_fallthrough;
1675 default:
1676 WARN_ON_ONCE(1);
1677 }
1678 list_del(&event_recorder->priv->parent.node);
1679 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
1680 kmem_cache_free(event_recorder_cache, event_recorder);
1681 break;
1682 }
1683 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1684 {
1685 struct lttng_kernel_event_notifier *event_notifier =
1686 container_of(event, struct lttng_kernel_event_notifier, parent);
1687
1688 switch (event_notifier->priv->parent.instrumentation) {
1689 case LTTNG_KERNEL_ABI_TRACEPOINT:
1690 lttng_event_desc_put(event_notifier->priv->parent.desc);
1691 break;
1692
1693 case LTTNG_KERNEL_ABI_KPROBE:
1694 module_put(event_notifier->priv->parent.desc->owner);
1695 lttng_kprobes_destroy_event_private(&event_notifier->parent);
1696 break;
1697
1698 case LTTNG_KERNEL_ABI_SYSCALL:
1699 break;
1700
1701 case LTTNG_KERNEL_ABI_UPROBE:
1702 module_put(event_notifier->priv->parent.desc->owner);
1703 lttng_uprobes_destroy_event_private(&event_notifier->parent);
1704 break;
1705
1706 case LTTNG_KERNEL_ABI_KRETPROBE:
1707 lttng_fallthrough;
1708 case LTTNG_KERNEL_ABI_FUNCTION:
1709 lttng_fallthrough;
1710 case LTTNG_KERNEL_ABI_NOOP:
1711 lttng_fallthrough;
1712 default:
1713 WARN_ON_ONCE(1);
1714 }
1715 list_del(&event_notifier->priv->parent.node);
1716 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1717 kmem_cache_free(event_notifier_cache, event_notifier);
1718 break;
1719 }
1720 default:
1721 WARN_ON_ONCE(1);
1722 }
1723 }
1724
1725 struct lttng_kernel_id_tracker *get_tracker(struct lttng_kernel_session *session,
1726 enum tracker_type tracker_type)
1727 {
1728 switch (tracker_type) {
1729 case TRACKER_PID:
1730 return &session->pid_tracker;
1731 case TRACKER_VPID:
1732 return &session->vpid_tracker;
1733 case TRACKER_UID:
1734 return &session->uid_tracker;
1735 case TRACKER_VUID:
1736 return &session->vuid_tracker;
1737 case TRACKER_GID:
1738 return &session->gid_tracker;
1739 case TRACKER_VGID:
1740 return &session->vgid_tracker;
1741 default:
1742 WARN_ON_ONCE(1);
1743 return NULL;
1744 }
1745 }
1746
1747 int lttng_session_track_id(struct lttng_kernel_session *session,
1748 enum tracker_type tracker_type, int id)
1749 {
1750 struct lttng_kernel_id_tracker *tracker;
1751 int ret;
1752
1753 tracker = get_tracker(session, tracker_type);
1754 if (!tracker)
1755 return -EINVAL;
1756 if (id < -1)
1757 return -EINVAL;
1758 mutex_lock(&sessions_mutex);
1759 if (id == -1) {
1760 /* track all ids: destroy tracker. */
1761 lttng_id_tracker_destroy(tracker, true);
1762 ret = 0;
1763 } else {
1764 ret = lttng_id_tracker_add(tracker, id);
1765 }
1766 mutex_unlock(&sessions_mutex);
1767 return ret;
1768 }
1769
1770 int lttng_session_untrack_id(struct lttng_kernel_session *session,
1771 enum tracker_type tracker_type, int id)
1772 {
1773 struct lttng_kernel_id_tracker *tracker;
1774 int ret;
1775
1776 tracker = get_tracker(session, tracker_type);
1777 if (!tracker)
1778 return -EINVAL;
1779 if (id < -1)
1780 return -EINVAL;
1781 mutex_lock(&sessions_mutex);
1782 if (id == -1) {
1783 /* untrack all ids: replace by empty tracker. */
1784 ret = lttng_id_tracker_empty_set(tracker);
1785 } else {
1786 ret = lttng_id_tracker_del(tracker, id);
1787 }
1788 mutex_unlock(&sessions_mutex);
1789 return ret;
1790 }
1791
1792 static
1793 void *id_list_start(struct seq_file *m, loff_t *pos)
1794 {
1795 struct lttng_kernel_id_tracker *id_tracker = m->private;
1796 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1797 struct lttng_id_hash_node *e;
1798 int iter = 0, i;
1799
1800 mutex_lock(&sessions_mutex);
1801 if (id_tracker_p) {
1802 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1803 struct hlist_head *head = &id_tracker_p->id_hash[i];
1804
1805 lttng_hlist_for_each_entry(e, head, hlist) {
1806 if (iter++ >= *pos)
1807 return e;
1808 }
1809 }
1810 } else {
1811 /* ID tracker disabled. */
1812 if (iter >= *pos && iter == 0) {
1813 return id_tracker_p; /* empty tracker */
1814 }
1815 iter++;
1816 }
1817 /* End of list */
1818 return NULL;
1819 }
1820
1821 /* Called with sessions_mutex held. */
1822 static
1823 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1824 {
1825 struct lttng_kernel_id_tracker *id_tracker = m->private;
1826 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1827 struct lttng_id_hash_node *e;
1828 int iter = 0, i;
1829
1830 (*ppos)++;
1831 if (id_tracker_p) {
1832 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1833 struct hlist_head *head = &id_tracker_p->id_hash[i];
1834
1835 lttng_hlist_for_each_entry(e, head, hlist) {
1836 if (iter++ >= *ppos)
1837 return e;
1838 }
1839 }
1840 } else {
1841 /* ID tracker disabled. */
1842 if (iter >= *ppos && iter == 0)
1843 return p; /* empty tracker */
1844 iter++;
1845 }
1846
1847 /* End of list */
1848 return NULL;
1849 }
1850
1851 static
1852 void id_list_stop(struct seq_file *m, void *p)
1853 {
1854 mutex_unlock(&sessions_mutex);
1855 }
1856
1857 static
1858 int id_list_show(struct seq_file *m, void *p)
1859 {
1860 struct lttng_kernel_id_tracker *id_tracker = m->private;
1861 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1862 int id;
1863
1864 if (p == id_tracker_p) {
1865 /* Tracker disabled. */
1866 id = -1;
1867 } else {
1868 const struct lttng_id_hash_node *e = p;
1869
1870 id = lttng_id_tracker_get_node_id(e);
1871 }
1872 switch (id_tracker->priv->tracker_type) {
1873 case TRACKER_PID:
1874 seq_printf(m, "process { pid = %d; };\n", id);
1875 break;
1876 case TRACKER_VPID:
1877 seq_printf(m, "process { vpid = %d; };\n", id);
1878 break;
1879 case TRACKER_UID:
1880 seq_printf(m, "user { uid = %d; };\n", id);
1881 break;
1882 case TRACKER_VUID:
1883 seq_printf(m, "user { vuid = %d; };\n", id);
1884 break;
1885 case TRACKER_GID:
1886 seq_printf(m, "group { gid = %d; };\n", id);
1887 break;
1888 case TRACKER_VGID:
1889 seq_printf(m, "group { vgid = %d; };\n", id);
1890 break;
1891 default:
1892 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1893 }
1894 return 0;
1895 }
1896
1897 static
1898 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1899 .start = id_list_start,
1900 .next = id_list_next,
1901 .stop = id_list_stop,
1902 .show = id_list_show,
1903 };
1904
1905 static
1906 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1907 {
1908 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1909 }
1910
1911 static
1912 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1913 {
1914 struct seq_file *m = file->private_data;
1915 struct lttng_kernel_id_tracker *id_tracker = m->private;
1916 int ret;
1917
1918 WARN_ON_ONCE(!id_tracker);
1919 ret = seq_release(inode, file);
1920 if (!ret)
1921 fput(id_tracker->priv->session->priv->file);
1922 return ret;
1923 }
1924
1925 const struct file_operations lttng_tracker_ids_list_fops = {
1926 .owner = THIS_MODULE,
1927 .open = lttng_tracker_ids_list_open,
1928 .read = seq_read,
1929 .llseek = seq_lseek,
1930 .release = lttng_tracker_ids_list_release,
1931 };
1932
1933 int lttng_session_list_tracker_ids(struct lttng_kernel_session *session,
1934 enum tracker_type tracker_type)
1935 {
1936 struct file *tracker_ids_list_file;
1937 struct seq_file *m;
1938 int file_fd, ret;
1939
1940 file_fd = lttng_get_unused_fd();
1941 if (file_fd < 0) {
1942 ret = file_fd;
1943 goto fd_error;
1944 }
1945
1946 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1947 &lttng_tracker_ids_list_fops,
1948 NULL, O_RDWR);
1949 if (IS_ERR(tracker_ids_list_file)) {
1950 ret = PTR_ERR(tracker_ids_list_file);
1951 goto file_error;
1952 }
1953 if (!atomic_long_add_unless(&session->priv->file->f_count, 1, LONG_MAX)) {
1954 ret = -EOVERFLOW;
1955 goto refcount_error;
1956 }
1957 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1958 if (ret < 0)
1959 goto open_error;
1960 m = tracker_ids_list_file->private_data;
1961
1962 m->private = get_tracker(session, tracker_type);
1963 BUG_ON(!m->private);
1964 fd_install(file_fd, tracker_ids_list_file);
1965
1966 return file_fd;
1967
1968 open_error:
1969 atomic_long_dec(&session->priv->file->f_count);
1970 refcount_error:
1971 fput(tracker_ids_list_file);
1972 file_error:
1973 put_unused_fd(file_fd);
1974 fd_error:
1975 return ret;
1976 }
1977
1978 /*
1979 * Enabler management.
1980 */
1981 static
1982 int lttng_match_enabler_star_glob(const char *desc_name,
1983 const char *pattern)
1984 {
1985 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
1986 desc_name, LTTNG_SIZE_MAX))
1987 return 0;
1988 return 1;
1989 }
1990
1991 static
1992 int lttng_match_enabler_name(const char *desc_name,
1993 const char *name)
1994 {
1995 if (strcmp(desc_name, name))
1996 return 0;
1997 return 1;
1998 }
1999
2000 static
2001 int lttng_desc_match_enabler_check(const struct lttng_kernel_event_desc *desc,
2002 struct lttng_event_enabler_common *enabler)
2003 {
2004 const char *desc_name, *enabler_name;
2005 bool compat = false, entry = false;
2006
2007 enabler_name = enabler->event_param.name;
2008 switch (enabler->event_param.instrumentation) {
2009 case LTTNG_KERNEL_ABI_TRACEPOINT:
2010 desc_name = desc->event_name;
2011 switch (enabler->format_type) {
2012 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2013 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2014 case LTTNG_ENABLER_FORMAT_NAME:
2015 return lttng_match_enabler_name(desc_name, enabler_name);
2016 default:
2017 return -EINVAL;
2018 }
2019 break;
2020
2021 case LTTNG_KERNEL_ABI_SYSCALL:
2022 desc_name = desc->event_name;
2023 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
2024 desc_name += strlen("compat_");
2025 compat = true;
2026 }
2027 if (!strncmp(desc_name, "syscall_exit_",
2028 strlen("syscall_exit_"))) {
2029 desc_name += strlen("syscall_exit_");
2030 } else if (!strncmp(desc_name, "syscall_entry_",
2031 strlen("syscall_entry_"))) {
2032 desc_name += strlen("syscall_entry_");
2033 entry = true;
2034 } else {
2035 WARN_ON_ONCE(1);
2036 return -EINVAL;
2037 }
2038 switch (enabler->event_param.u.syscall.entryexit) {
2039 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
2040 break;
2041 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
2042 if (!entry)
2043 return 0;
2044 break;
2045 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
2046 if (entry)
2047 return 0;
2048 break;
2049 default:
2050 return -EINVAL;
2051 }
2052 switch (enabler->event_param.u.syscall.abi) {
2053 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
2054 break;
2055 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
2056 if (compat)
2057 return 0;
2058 break;
2059 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
2060 if (!compat)
2061 return 0;
2062 break;
2063 default:
2064 return -EINVAL;
2065 }
2066 switch (enabler->event_param.u.syscall.match) {
2067 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
2068 switch (enabler->format_type) {
2069 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2070 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2071 case LTTNG_ENABLER_FORMAT_NAME:
2072 return lttng_match_enabler_name(desc_name, enabler_name);
2073 default:
2074 return -EINVAL;
2075 }
2076 break;
2077 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
2078 return -EINVAL; /* Not implemented. */
2079 default:
2080 return -EINVAL;
2081 }
2082 break;
2083
2084 default:
2085 WARN_ON_ONCE(1);
2086 return -EINVAL;
2087 }
2088 }
2089
2090 bool lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
2091 struct lttng_event_enabler_common *enabler)
2092 {
2093 int ret;
2094
2095 ret = lttng_desc_match_enabler_check(desc, enabler);
2096 if (ret < 0) {
2097 WARN_ON_ONCE(1);
2098 return false;
2099 }
2100 return ret;
2101 }
2102
2103 bool lttng_event_enabler_match_event(struct lttng_event_enabler_common *event_enabler,
2104 struct lttng_kernel_event_common *event)
2105 {
2106 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2107 return false;
2108
2109 switch (event_enabler->enabler_type) {
2110 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2111 {
2112 struct lttng_event_recorder_enabler *event_recorder_enabler =
2113 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2114 struct lttng_kernel_event_recorder *event_recorder =
2115 container_of(event, struct lttng_kernel_event_recorder, parent);
2116
2117 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
2118 && event_recorder->chan == event_recorder_enabler->chan)
2119 return true;
2120 else
2121 return false;
2122 }
2123 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2124 {
2125 struct lttng_event_notifier_enabler *event_notifier_enabler =
2126 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2127 struct lttng_kernel_event_notifier *event_notifier =
2128 container_of(event, struct lttng_kernel_event_notifier, parent);
2129
2130 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
2131 && event_notifier->priv->group == event_notifier_enabler->group
2132 && event->priv->user_token == event_enabler->user_token)
2133 return true;
2134 else
2135 return false;
2136 }
2137 default:
2138 WARN_ON_ONCE(1);
2139 return false;
2140 }
2141 }
2142
2143 bool lttng_event_enabler_desc_match_event(struct lttng_event_enabler_common *event_enabler,
2144 const struct lttng_kernel_event_desc *desc,
2145 struct lttng_kernel_event_common *event)
2146 {
2147 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2148 return false;
2149
2150 switch (event_enabler->enabler_type) {
2151 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2152 {
2153 struct lttng_event_recorder_enabler *event_recorder_enabler =
2154 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2155 struct lttng_kernel_event_recorder *event_recorder =
2156 container_of(event, struct lttng_kernel_event_recorder, parent);
2157
2158 if (event->priv->desc == desc && event_recorder->chan == event_recorder_enabler->chan)
2159 return true;
2160 else
2161 return false;
2162 }
2163 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2164 {
2165 struct lttng_event_notifier_enabler *event_notifier_enabler =
2166 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2167 struct lttng_kernel_event_notifier *event_notifier =
2168 container_of(event, struct lttng_kernel_event_notifier, parent);
2169
2170 if (event->priv->desc == desc
2171 && event_notifier->priv->group == event_notifier_enabler->group
2172 && event->priv->user_token == event_enabler->user_token)
2173 return true;
2174 else
2175 return false;
2176 }
2177 default:
2178 WARN_ON_ONCE(1);
2179 return false;
2180 }
2181 }
2182
2183 bool lttng_event_enabler_event_name_match_event(struct lttng_event_enabler_common *event_enabler,
2184 const char *event_name,
2185 struct lttng_kernel_event_common *event)
2186 {
2187 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2188 return false;
2189
2190 switch (event_enabler->enabler_type) {
2191 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2192 {
2193 struct lttng_event_recorder_enabler *event_recorder_enabler =
2194 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2195 struct lttng_kernel_event_recorder *event_recorder =
2196 container_of(event, struct lttng_kernel_event_recorder, parent);
2197
2198 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2199 && event_recorder->chan == event_recorder_enabler->chan)
2200 return true;
2201 else
2202 return false;
2203 }
2204 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2205 {
2206 struct lttng_event_notifier_enabler *event_notifier_enabler =
2207 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2208 struct lttng_kernel_event_notifier *event_notifier =
2209 container_of(event, struct lttng_kernel_event_notifier, parent);
2210
2211 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2212 && event_notifier->priv->group == event_notifier_enabler->group
2213 && event->priv->user_token == event_enabler->user_token)
2214 return true;
2215 else
2216 return false;
2217 }
2218 default:
2219 WARN_ON_ONCE(1);
2220 return false;
2221 }
2222 }
2223
2224 static
2225 struct lttng_enabler_ref *lttng_enabler_ref(
2226 struct list_head *enablers_ref_list,
2227 struct lttng_event_enabler_common *enabler)
2228 {
2229 struct lttng_enabler_ref *enabler_ref;
2230
2231 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2232 if (enabler_ref->ref == enabler)
2233 return enabler_ref;
2234 }
2235 return NULL;
2236 }
2237
2238 static
2239 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler_common *event_enabler)
2240 {
2241 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(event_enabler);
2242 struct lttng_kernel_probe_desc *probe_desc;
2243 const struct lttng_kernel_event_desc *desc;
2244 struct list_head *probe_list;
2245 int i;
2246
2247 probe_list = lttng_get_probe_list_head();
2248 /*
2249 * For each probe event, if we find that a probe event matches
2250 * our enabler, create an associated lttng_event if not
2251 * already present.
2252 */
2253 list_for_each_entry(probe_desc, probe_list, head) {
2254 for (i = 0; i < probe_desc->nr_events; i++) {
2255 int found = 0;
2256 struct hlist_head *head;
2257 struct lttng_kernel_event_common *event;
2258 struct lttng_kernel_event_common_private *event_priv;
2259
2260 desc = probe_desc->event_desc[i];
2261 if (!lttng_desc_match_enabler(desc, event_enabler))
2262 continue;
2263
2264 /*
2265 * Check if already created.
2266 */
2267 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
2268 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
2269 if (lttng_event_enabler_desc_match_event(event_enabler, desc, event_priv->pub))
2270 found = 1;
2271 }
2272 if (found)
2273 continue;
2274
2275 /*
2276 * We need to create an event for this event probe.
2277 */
2278 event = _lttng_kernel_event_create(event_enabler, desc);
2279 if (!event) {
2280 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2281 probe_desc->event_desc[i]->event_name);
2282 }
2283 }
2284 }
2285 }
2286
2287 static
2288 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler_common *event_enabler)
2289 {
2290 int ret;
2291
2292 ret = lttng_syscalls_register_event(event_enabler);
2293 WARN_ON_ONCE(ret);
2294 }
2295
2296 /*
2297 * Create event if it is missing and present in the list of tracepoint probes.
2298 * Should be called with sessions mutex held.
2299 */
2300 static
2301 void lttng_create_event_if_missing(struct lttng_event_enabler_common *event_enabler)
2302 {
2303 switch (event_enabler->event_param.instrumentation) {
2304 case LTTNG_KERNEL_ABI_TRACEPOINT:
2305 lttng_create_tracepoint_event_if_missing(event_enabler);
2306 break;
2307
2308 case LTTNG_KERNEL_ABI_SYSCALL:
2309 lttng_create_syscall_event_if_missing(event_enabler);
2310 break;
2311
2312 default:
2313 WARN_ON_ONCE(1);
2314 break;
2315 }
2316 }
2317
2318 static
2319 void lttng_event_enabler_init_event_filter(struct lttng_event_enabler_common *event_enabler,
2320 struct lttng_kernel_event_common *event)
2321 {
2322 /* Link filter bytecodes if not linked yet. */
2323 lttng_enabler_link_bytecode(event->priv->desc, lttng_static_ctx,
2324 &event->priv->filter_bytecode_runtime_head, &event_enabler->filter_bytecode_head);
2325 }
2326
2327 static
2328 void lttng_event_enabler_init_event_capture(struct lttng_event_enabler_common *event_enabler,
2329 struct lttng_kernel_event_common *event)
2330 {
2331 switch (event_enabler->enabler_type) {
2332 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2333 break;
2334 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2335 {
2336 struct lttng_event_notifier_enabler *event_notifier_enabler =
2337 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2338 struct lttng_kernel_event_notifier *event_notifier =
2339 container_of(event, struct lttng_kernel_event_notifier, parent);
2340
2341 /* Link capture bytecodes if not linked yet. */
2342 lttng_enabler_link_bytecode(event->priv->desc,
2343 lttng_static_ctx, &event_notifier->priv->capture_bytecode_runtime_head,
2344 &event_notifier_enabler->capture_bytecode_head);
2345 event_notifier->priv->num_captures = event_notifier_enabler->num_captures;
2346 break;
2347 }
2348 default:
2349 WARN_ON_ONCE(1);
2350 }
2351 }
2352
2353 /*
2354 * Create events associated with an event_enabler (if not already present),
2355 * and add backward reference from the event to the enabler.
2356 * Should be called with sessions mutex held.
2357 */
2358 static
2359 int lttng_event_enabler_ref_events(struct lttng_event_enabler_common *event_enabler)
2360 {
2361 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(event_enabler);
2362 struct lttng_kernel_event_common_private *event_priv;
2363
2364 lttng_syscall_table_set_wildcard_all(event_enabler);
2365
2366 /* First ensure that probe events are created for this enabler. */
2367 lttng_create_event_if_missing(event_enabler);
2368
2369 /* Link the created event with its associated enabler. */
2370 list_for_each_entry(event_priv, event_list_head, node) {
2371 struct lttng_kernel_event_common *event = event_priv->pub;
2372 struct lttng_enabler_ref *enabler_ref;
2373
2374 if (!lttng_event_enabler_match_event(event_enabler, event))
2375 continue;
2376
2377 enabler_ref = lttng_enabler_ref(&event_priv->enablers_ref_head, event_enabler);
2378 if (!enabler_ref) {
2379 /*
2380 * If no backward ref, create it.
2381 * Add backward ref from event_notifier to enabler.
2382 */
2383 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2384 if (!enabler_ref)
2385 return -ENOMEM;
2386
2387 enabler_ref->ref = event_enabler;
2388 list_add(&enabler_ref->node, &event_priv->enablers_ref_head);
2389 }
2390
2391 lttng_event_enabler_init_event_filter(event_enabler, event);
2392 lttng_event_enabler_init_event_capture(event_enabler, event);
2393 }
2394 return 0;
2395 }
2396
2397 /*
2398 * Called at module load: connect the probe on all enablers matching
2399 * this event.
2400 * Called with sessions lock held.
2401 */
2402 int lttng_fix_pending_events(void)
2403 {
2404 struct lttng_kernel_session_private *session_priv;
2405
2406 list_for_each_entry(session_priv, &sessions, list)
2407 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2408 return 0;
2409 }
2410
2411 static bool lttng_event_notifier_group_has_active_event_notifiers(
2412 struct lttng_event_notifier_group *event_notifier_group)
2413 {
2414 struct lttng_event_enabler_common *event_enabler;
2415
2416 list_for_each_entry(event_enabler, &event_notifier_group->enablers_head, node) {
2417 if (event_enabler->enabled)
2418 return true;
2419 }
2420 return false;
2421 }
2422
2423 bool lttng_event_notifier_active(void)
2424 {
2425 struct lttng_event_notifier_group *event_notifier_group;
2426
2427 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2428 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2429 return true;
2430 }
2431 return false;
2432 }
2433
2434 int lttng_fix_pending_event_notifiers(void)
2435 {
2436 struct lttng_event_notifier_group *event_notifier_group;
2437
2438 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2439 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2440 return 0;
2441 }
2442
2443 struct lttng_event_recorder_enabler *lttng_event_recorder_enabler_create(
2444 enum lttng_enabler_format_type format_type,
2445 struct lttng_kernel_abi_event *event_param,
2446 struct lttng_kernel_channel_buffer *chan)
2447 {
2448 struct lttng_event_recorder_enabler *event_enabler;
2449
2450 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2451 if (!event_enabler)
2452 return NULL;
2453 event_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_RECORDER;
2454 event_enabler->parent.format_type = format_type;
2455 INIT_LIST_HEAD(&event_enabler->parent.filter_bytecode_head);
2456 memcpy(&event_enabler->parent.event_param, event_param,
2457 sizeof(event_enabler->parent.event_param));
2458 event_enabler->chan = chan;
2459 /* ctx left NULL */
2460 event_enabler->parent.enabled = 0;
2461 return event_enabler;
2462 }
2463
2464 void lttng_event_enabler_session_add(struct lttng_kernel_session *session,
2465 struct lttng_event_recorder_enabler *event_enabler)
2466 {
2467 mutex_lock(&sessions_mutex);
2468 list_add(&event_enabler->parent.node, &session->priv->enablers_head);
2469 event_enabler->parent.published = true;
2470 lttng_session_lazy_sync_event_enablers(session);
2471 mutex_unlock(&sessions_mutex);
2472 }
2473
2474 int lttng_event_enabler_enable(struct lttng_event_enabler_common *event_enabler)
2475 {
2476 mutex_lock(&sessions_mutex);
2477 event_enabler->enabled = 1;
2478 lttng_event_enabler_sync(event_enabler);
2479 mutex_unlock(&sessions_mutex);
2480 return 0;
2481 }
2482
2483 int lttng_event_enabler_disable(struct lttng_event_enabler_common *event_enabler)
2484 {
2485 mutex_lock(&sessions_mutex);
2486 event_enabler->enabled = 0;
2487 lttng_event_enabler_sync(event_enabler);
2488 mutex_unlock(&sessions_mutex);
2489 return 0;
2490 }
2491
2492 static
2493 int lttng_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *enabler,
2494 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2495 {
2496 struct lttng_kernel_bytecode_node *bytecode_node;
2497 uint32_t bytecode_len;
2498 int ret;
2499
2500 ret = get_user(bytecode_len, &bytecode->len);
2501 if (ret)
2502 return ret;
2503 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2504 GFP_KERNEL);
2505 if (!bytecode_node)
2506 return -ENOMEM;
2507 ret = copy_from_user(&bytecode_node->bc, bytecode,
2508 sizeof(*bytecode) + bytecode_len);
2509 if (ret)
2510 goto error_free;
2511
2512 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2513 bytecode_node->enabler = enabler;
2514 /* Enforce length based on allocated size */
2515 bytecode_node->bc.len = bytecode_len;
2516 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2517
2518 return 0;
2519
2520 error_free:
2521 lttng_kvfree(bytecode_node);
2522 return ret;
2523 }
2524
2525 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *event_enabler,
2526 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2527 {
2528 int ret;
2529 ret = lttng_enabler_attach_filter_bytecode(event_enabler, bytecode);
2530 if (ret)
2531 goto error;
2532 lttng_event_enabler_sync(event_enabler);
2533 return 0;
2534
2535 error:
2536 return ret;
2537 }
2538
2539 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2540 struct lttng_kernel_abi_event_callsite __user *callsite)
2541 {
2542
2543 switch (event->priv->instrumentation) {
2544 case LTTNG_KERNEL_ABI_UPROBE:
2545 return lttng_uprobes_event_add_callsite(event, callsite);
2546 default:
2547 return -EINVAL;
2548 }
2549 }
2550
2551 static
2552 void lttng_enabler_destroy(struct lttng_event_enabler_common *enabler)
2553 {
2554 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2555
2556 /* Destroy filter bytecode */
2557 list_for_each_entry_safe(filter_node, tmp_filter_node,
2558 &enabler->filter_bytecode_head, node) {
2559 lttng_kvfree(filter_node);
2560 }
2561 }
2562
2563 void lttng_event_enabler_destroy(struct lttng_event_enabler_common *event_enabler)
2564 {
2565 lttng_enabler_destroy(event_enabler);
2566 if (event_enabler->published)
2567 list_del(&event_enabler->node);
2568
2569 switch (event_enabler->enabler_type) {
2570 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2571 {
2572 struct lttng_event_recorder_enabler *event_recorder_enabler =
2573 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2574
2575 kfree(event_recorder_enabler);
2576 break;
2577 }
2578 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2579 {
2580 struct lttng_event_notifier_enabler *event_notifier_enabler =
2581 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2582
2583 kfree(event_notifier_enabler);
2584 break;
2585 }
2586 default:
2587 WARN_ON_ONCE(1);
2588 }
2589 }
2590
2591 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2592 enum lttng_enabler_format_type format_type,
2593 struct lttng_kernel_abi_event_notifier *event_notifier_param,
2594 struct lttng_event_notifier_group *event_notifier_group)
2595 {
2596 struct lttng_event_notifier_enabler *event_notifier_enabler;
2597
2598 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2599 if (!event_notifier_enabler)
2600 return NULL;
2601
2602 event_notifier_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_NOTIFIER;
2603 event_notifier_enabler->parent.format_type = format_type;
2604 INIT_LIST_HEAD(&event_notifier_enabler->parent.filter_bytecode_head);
2605 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2606
2607 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2608 event_notifier_enabler->num_captures = 0;
2609
2610 memcpy(&event_notifier_enabler->parent.event_param, &event_notifier_param->event,
2611 sizeof(event_notifier_enabler->parent.event_param));
2612
2613 event_notifier_enabler->parent.enabled = 0;
2614 event_notifier_enabler->parent.user_token = event_notifier_param->event.token;
2615 event_notifier_enabler->group = event_notifier_group;
2616 return event_notifier_enabler;
2617 }
2618
2619 void lttng_event_notifier_enabler_group_add(struct lttng_event_notifier_group *event_notifier_group,
2620 struct lttng_event_notifier_enabler *event_notifier_enabler)
2621 {
2622 mutex_lock(&sessions_mutex);
2623 list_add(&event_notifier_enabler->parent.node, &event_notifier_enabler->group->enablers_head);
2624 event_notifier_enabler->parent.published = true;
2625 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2626 mutex_unlock(&sessions_mutex);
2627 }
2628
2629 int lttng_event_notifier_enabler_enable(
2630 struct lttng_event_notifier_enabler *event_notifier_enabler)
2631 {
2632 mutex_lock(&sessions_mutex);
2633 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2634 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2635 mutex_unlock(&sessions_mutex);
2636 return 0;
2637 }
2638
2639 int lttng_event_notifier_enabler_disable(
2640 struct lttng_event_notifier_enabler *event_notifier_enabler)
2641 {
2642 mutex_lock(&sessions_mutex);
2643 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2644 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2645 mutex_unlock(&sessions_mutex);
2646 return 0;
2647 }
2648
2649 int lttng_event_notifier_enabler_attach_capture_bytecode(
2650 struct lttng_event_notifier_enabler *event_notifier_enabler,
2651 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2652 {
2653 struct lttng_kernel_bytecode_node *bytecode_node;
2654 struct lttng_event_enabler_common *enabler =
2655 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2656 uint32_t bytecode_len;
2657 int ret;
2658
2659 ret = get_user(bytecode_len, &bytecode->len);
2660 if (ret)
2661 return ret;
2662
2663 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2664 GFP_KERNEL);
2665 if (!bytecode_node)
2666 return -ENOMEM;
2667
2668 ret = copy_from_user(&bytecode_node->bc, bytecode,
2669 sizeof(*bytecode) + bytecode_len);
2670 if (ret)
2671 goto error_free;
2672
2673 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2674 bytecode_node->enabler = enabler;
2675
2676 /* Enforce length based on allocated size */
2677 bytecode_node->bc.len = bytecode_len;
2678 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2679
2680 event_notifier_enabler->num_captures++;
2681
2682 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2683 goto end;
2684
2685 error_free:
2686 lttng_kvfree(bytecode_node);
2687 end:
2688 return ret;
2689 }
2690
2691 static
2692 void lttng_event_sync_filter_state(struct lttng_kernel_event_common *event)
2693 {
2694 int has_enablers_without_filter_bytecode = 0, nr_filters = 0;
2695 struct lttng_kernel_bytecode_runtime *runtime;
2696 struct lttng_enabler_ref *enabler_ref;
2697
2698 /* Check if has enablers without bytecode enabled */
2699 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2700 if (enabler_ref->ref->enabled
2701 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2702 has_enablers_without_filter_bytecode = 1;
2703 break;
2704 }
2705 }
2706 event->priv->has_enablers_without_filter_bytecode = has_enablers_without_filter_bytecode;
2707
2708 /* Enable filters */
2709 list_for_each_entry(runtime, &event->priv->filter_bytecode_runtime_head, node) {
2710 lttng_bytecode_sync_state(runtime);
2711 nr_filters++;
2712 }
2713 WRITE_ONCE(event->eval_filter, !(has_enablers_without_filter_bytecode || !nr_filters));
2714 }
2715
2716 static
2717 void lttng_event_sync_capture_state(struct lttng_kernel_event_common *event)
2718 {
2719 switch (event->type) {
2720 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2721 break;
2722 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2723 {
2724 struct lttng_kernel_event_notifier *event_notifier =
2725 container_of(event, struct lttng_kernel_event_notifier, parent);
2726 struct lttng_kernel_bytecode_runtime *runtime;
2727 int nr_captures = 0;
2728
2729 /* Enable captures */
2730 list_for_each_entry(runtime, &event_notifier->priv->capture_bytecode_runtime_head, node) {
2731 lttng_bytecode_sync_state(runtime);
2732 nr_captures++;
2733 }
2734 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2735 break;
2736 }
2737 default:
2738 WARN_ON_ONCE(1);
2739 }
2740 }
2741
2742 static
2743 bool lttng_get_event_enabled_state(struct lttng_kernel_event_common *event)
2744 {
2745 struct lttng_enabler_ref *enabler_ref;
2746 bool enabled = false;
2747
2748 switch (event->priv->instrumentation) {
2749 case LTTNG_KERNEL_ABI_TRACEPOINT:
2750 lttng_fallthrough;
2751 case LTTNG_KERNEL_ABI_SYSCALL:
2752 /* Enable events */
2753 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2754 if (enabler_ref->ref->enabled) {
2755 enabled = true;
2756 break;
2757 }
2758 }
2759 break;
2760 default:
2761 WARN_ON_ONCE(1);
2762 return false;
2763 }
2764
2765 switch (event->type) {
2766 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2767 {
2768 struct lttng_kernel_event_recorder *event_recorder =
2769 container_of(event, struct lttng_kernel_event_recorder, parent);
2770
2771 /*
2772 * Enabled state is based on union of enablers, with
2773 * intersection of session and channel transient enable
2774 * states.
2775 */
2776 return enabled && event_recorder->chan->parent.session->priv->tstate && event_recorder->chan->priv->parent.tstate;
2777 }
2778 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2779 return enabled;
2780 default:
2781 WARN_ON_ONCE(1);
2782 return false;
2783 }
2784 }
2785
2786 static
2787 bool lttng_event_is_lazy_sync(struct lttng_kernel_event_common *event)
2788 {
2789 switch (event->priv->instrumentation) {
2790 case LTTNG_KERNEL_ABI_TRACEPOINT:
2791 lttng_fallthrough;
2792 case LTTNG_KERNEL_ABI_SYSCALL:
2793 return true;
2794
2795 default:
2796 /* Not handled with lazy sync. */
2797 return false;
2798 }
2799 }
2800
2801 /*
2802 * Should be called with sessions mutex held.
2803 */
2804 static
2805 void lttng_sync_event_list(struct list_head *event_enabler_list,
2806 struct list_head *event_list)
2807 {
2808 struct lttng_kernel_event_common_private *event_priv;
2809 struct lttng_event_enabler_common *event_enabler;
2810
2811 list_for_each_entry(event_enabler, event_enabler_list, node)
2812 lttng_event_enabler_ref_events(event_enabler);
2813
2814 /*
2815 * For each event, if at least one of its enablers is enabled,
2816 * and its channel and session transient states are enabled, we
2817 * enable the event, else we disable it.
2818 */
2819 list_for_each_entry(event_priv, event_list, node) {
2820 struct lttng_kernel_event_common *event = event_priv->pub;
2821 bool enabled;
2822
2823 if (!lttng_event_is_lazy_sync(event))
2824 continue;
2825
2826 enabled = lttng_get_event_enabled_state(event);
2827 WRITE_ONCE(event->enabled, enabled);
2828 /*
2829 * Sync tracepoint registration with event enabled state.
2830 */
2831 if (enabled) {
2832 register_event(event);
2833 } else {
2834 _lttng_event_unregister(event);
2835 }
2836
2837 lttng_event_sync_filter_state(event);
2838 lttng_event_sync_capture_state(event);
2839 }
2840 }
2841
2842 /*
2843 * lttng_session_sync_event_enablers should be called just before starting a
2844 * session.
2845 */
2846 static
2847 void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2848 {
2849 lttng_sync_event_list(&session->priv->enablers_head, &session->priv->events);
2850 }
2851
2852 /*
2853 * Apply enablers to session events, adding events to session if need
2854 * be. It is required after each modification applied to an active
2855 * session, and right before session "start".
2856 * "lazy" sync means we only sync if required.
2857 * Should be called with sessions mutex held.
2858 */
2859 static
2860 void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2861 {
2862 /* We can skip if session is not active */
2863 if (!session->active)
2864 return;
2865 lttng_session_sync_event_enablers(session);
2866 }
2867
2868 static
2869 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2870 {
2871 lttng_sync_event_list(&event_notifier_group->enablers_head, &event_notifier_group->event_notifiers_head);
2872 }
2873
2874 static
2875 void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler)
2876 {
2877 switch (event_enabler->enabler_type) {
2878 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2879 {
2880 struct lttng_event_recorder_enabler *event_recorder_enabler =
2881 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2882 lttng_session_lazy_sync_event_enablers(event_recorder_enabler->chan->parent.session);
2883 break;
2884 }
2885 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2886 {
2887 struct lttng_event_notifier_enabler *event_notifier_enabler =
2888 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2889 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2890 break;
2891 }
2892 default:
2893 WARN_ON_ONCE(1);
2894 }
2895 }
2896
2897 /*
2898 * Serialize at most one packet worth of metadata into a metadata
2899 * channel.
2900 * We grab the metadata cache mutex to get exclusive access to our metadata
2901 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2902 * allows us to do racy operations such as looking for remaining space left in
2903 * packet and write, since mutual exclusion protects us from concurrent writes.
2904 * Mutual exclusion on the metadata cache allow us to read the cache content
2905 * without racing against reallocation of the cache by updates.
2906 * Returns the number of bytes written in the channel, 0 if no data
2907 * was written and a negative value on error.
2908 */
2909 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2910 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2911 {
2912 struct lttng_kernel_ring_buffer_ctx ctx;
2913 int ret = 0;
2914 size_t len, reserve_len;
2915
2916 /*
2917 * Ensure we support mutiple get_next / put sequences followed by
2918 * put_next. The metadata cache lock protects reading the metadata
2919 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2920 * "flush" operations on the buffer invoked by different processes.
2921 * Moreover, since the metadata cache memory can be reallocated, we
2922 * need to have exclusive access against updates even though we only
2923 * read it.
2924 */
2925 mutex_lock(&stream->metadata_cache->lock);
2926 WARN_ON(stream->metadata_in < stream->metadata_out);
2927 if (stream->metadata_in != stream->metadata_out)
2928 goto end;
2929
2930 /* Metadata regenerated, change the version. */
2931 if (stream->metadata_cache->version != stream->version)
2932 stream->version = stream->metadata_cache->version;
2933
2934 len = stream->metadata_cache->metadata_written -
2935 stream->metadata_in;
2936 if (!len)
2937 goto end;
2938 reserve_len = min_t(size_t,
2939 stream->transport->ops.priv->packet_avail_size(chan),
2940 len);
2941 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2942 sizeof(char), NULL);
2943 /*
2944 * If reservation failed, return an error to the caller.
2945 */
2946 ret = stream->transport->ops.event_reserve(&ctx);
2947 if (ret != 0) {
2948 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2949 stream->coherent = false;
2950 goto end;
2951 }
2952 stream->transport->ops.event_write(&ctx,
2953 stream->metadata_cache->data + stream->metadata_in,
2954 reserve_len, 1);
2955 stream->transport->ops.event_commit(&ctx);
2956 stream->metadata_in += reserve_len;
2957 if (reserve_len < len)
2958 stream->coherent = false;
2959 else
2960 stream->coherent = true;
2961 ret = reserve_len;
2962
2963 end:
2964 if (coherent)
2965 *coherent = stream->coherent;
2966 mutex_unlock(&stream->metadata_cache->lock);
2967 return ret;
2968 }
2969
2970 static
2971 void lttng_metadata_begin(struct lttng_kernel_session *session)
2972 {
2973 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
2974 mutex_lock(&session->priv->metadata_cache->lock);
2975 }
2976
2977 static
2978 void lttng_metadata_end(struct lttng_kernel_session *session)
2979 {
2980 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2981 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
2982 struct lttng_metadata_stream *stream;
2983
2984 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
2985 wake_up_interruptible(&stream->read_wait);
2986 mutex_unlock(&session->priv->metadata_cache->lock);
2987 }
2988 }
2989
2990 /*
2991 * Write the metadata to the metadata cache.
2992 * Must be called with sessions_mutex held.
2993 * The metadata cache lock protects us from concurrent read access from
2994 * thread outputting metadata content to ring buffer.
2995 * The content of the printf is printed as a single atomic metadata
2996 * transaction.
2997 */
2998 int lttng_metadata_printf(struct lttng_kernel_session *session,
2999 const char *fmt, ...)
3000 {
3001 char *str;
3002 size_t len;
3003 va_list ap;
3004
3005 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
3006
3007 va_start(ap, fmt);
3008 str = kvasprintf(GFP_KERNEL, fmt, ap);
3009 va_end(ap);
3010 if (!str)
3011 return -ENOMEM;
3012
3013 len = strlen(str);
3014 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
3015 if (session->priv->metadata_cache->metadata_written + len >
3016 session->priv->metadata_cache->cache_alloc) {
3017 char *tmp_cache_realloc;
3018 unsigned int tmp_cache_alloc_size;
3019
3020 tmp_cache_alloc_size = max_t(unsigned int,
3021 session->priv->metadata_cache->cache_alloc + len,
3022 session->priv->metadata_cache->cache_alloc << 1);
3023 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
3024 if (!tmp_cache_realloc)
3025 goto err;
3026 if (session->priv->metadata_cache->data) {
3027 memcpy(tmp_cache_realloc,
3028 session->priv->metadata_cache->data,
3029 session->priv->metadata_cache->cache_alloc);
3030 vfree(session->priv->metadata_cache->data);
3031 }
3032
3033 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
3034 session->priv->metadata_cache->data = tmp_cache_realloc;
3035 }
3036 memcpy(session->priv->metadata_cache->data +
3037 session->priv->metadata_cache->metadata_written,
3038 str, len);
3039 session->priv->metadata_cache->metadata_written += len;
3040 kfree(str);
3041
3042 return 0;
3043
3044 err:
3045 kfree(str);
3046 return -ENOMEM;
3047 }
3048
3049 static
3050 int print_tabs(struct lttng_kernel_session *session, size_t nesting)
3051 {
3052 size_t i;
3053
3054 for (i = 0; i < nesting; i++) {
3055 int ret;
3056
3057 ret = lttng_metadata_printf(session, " ");
3058 if (ret) {
3059 return ret;
3060 }
3061 }
3062 return 0;
3063 }
3064
3065 static
3066 int lttng_field_name_statedump(struct lttng_kernel_session *session,
3067 const struct lttng_kernel_event_field *field,
3068 size_t nesting)
3069 {
3070 return lttng_metadata_printf(session, " _%s;\n", field->name);
3071 }
3072
3073 static
3074 int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
3075 const struct lttng_kernel_type_integer *type,
3076 enum lttng_kernel_string_encoding parent_encoding,
3077 size_t nesting)
3078 {
3079 int ret;
3080
3081 ret = print_tabs(session, nesting);
3082 if (ret)
3083 return ret;
3084 ret = lttng_metadata_printf(session,
3085 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
3086 type->size,
3087 type->alignment,
3088 type->signedness,
3089 (parent_encoding == lttng_kernel_string_encoding_none)
3090 ? "none"
3091 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
3092 ? "UTF8"
3093 : "ASCII",
3094 type->base,
3095 #if __BYTE_ORDER == __BIG_ENDIAN
3096 type->reverse_byte_order ? " byte_order = le;" : ""
3097 #else
3098 type->reverse_byte_order ? " byte_order = be;" : ""
3099 #endif
3100 );
3101 return ret;
3102 }
3103
3104 /*
3105 * Must be called with sessions_mutex held.
3106 */
3107 static
3108 int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
3109 const struct lttng_kernel_type_struct *type,
3110 size_t nesting)
3111 {
3112 const char *prev_field_name = NULL;
3113 int ret;
3114 uint32_t i, nr_fields;
3115 unsigned int alignment;
3116
3117 ret = print_tabs(session, nesting);
3118 if (ret)
3119 return ret;
3120 ret = lttng_metadata_printf(session,
3121 "struct {\n");
3122 if (ret)
3123 return ret;
3124 nr_fields = type->nr_fields;
3125 for (i = 0; i < nr_fields; i++) {
3126 const struct lttng_kernel_event_field *iter_field;
3127
3128 iter_field = type->fields[i];
3129 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
3130 if (ret)
3131 return ret;
3132 }
3133 ret = print_tabs(session, nesting);
3134 if (ret)
3135 return ret;
3136 alignment = type->alignment;
3137 if (alignment) {
3138 ret = lttng_metadata_printf(session,
3139 "} align(%u)",
3140 alignment);
3141 } else {
3142 ret = lttng_metadata_printf(session,
3143 "}");
3144 }
3145 return ret;
3146 }
3147
3148 /*
3149 * Must be called with sessions_mutex held.
3150 */
3151 static
3152 int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
3153 const struct lttng_kernel_event_field *field,
3154 size_t nesting)
3155 {
3156 int ret;
3157
3158 ret = _lttng_struct_type_statedump(session,
3159 lttng_kernel_get_type_struct(field->type), nesting);
3160 if (ret)
3161 return ret;
3162 return lttng_field_name_statedump(session, field, nesting);
3163 }
3164
3165 /*
3166 * Must be called with sessions_mutex held.
3167 */
3168 static
3169 int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
3170 const struct lttng_kernel_type_variant *type,
3171 size_t nesting,
3172 const char *prev_field_name)
3173 {
3174 const char *tag_name;
3175 int ret;
3176 uint32_t i, nr_choices;
3177
3178 tag_name = type->tag_name;
3179 if (!tag_name)
3180 tag_name = prev_field_name;
3181 if (!tag_name)
3182 return -EINVAL;
3183 /*
3184 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3185 */
3186 if (type->alignment != 0)
3187 return -EINVAL;
3188 ret = print_tabs(session, nesting);
3189 if (ret)
3190 return ret;
3191 ret = lttng_metadata_printf(session,
3192 "variant <_%s> {\n",
3193 tag_name);
3194 if (ret)
3195 return ret;
3196 nr_choices = type->nr_choices;
3197 for (i = 0; i < nr_choices; i++) {
3198 const struct lttng_kernel_event_field *iter_field;
3199
3200 iter_field = type->choices[i];
3201 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3202 if (ret)
3203 return ret;
3204 }
3205 ret = print_tabs(session, nesting);
3206 if (ret)
3207 return ret;
3208 ret = lttng_metadata_printf(session,
3209 "}");
3210 return ret;
3211 }
3212
3213 /*
3214 * Must be called with sessions_mutex held.
3215 */
3216 static
3217 int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3218 const struct lttng_kernel_event_field *field,
3219 size_t nesting,
3220 const char *prev_field_name)
3221 {
3222 int ret;
3223
3224 ret = _lttng_variant_type_statedump(session,
3225 lttng_kernel_get_type_variant(field->type), nesting,
3226 prev_field_name);
3227 if (ret)
3228 return ret;
3229 return lttng_field_name_statedump(session, field, nesting);
3230 }
3231
3232 /*
3233 * Must be called with sessions_mutex held.
3234 */
3235 static
3236 int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3237 const struct lttng_kernel_event_field *field,
3238 size_t nesting)
3239 {
3240 int ret;
3241 const struct lttng_kernel_type_array *array_type;
3242 const struct lttng_kernel_type_common *elem_type;
3243
3244 array_type = lttng_kernel_get_type_array(field->type);
3245 WARN_ON_ONCE(!array_type);
3246
3247 if (array_type->alignment) {
3248 ret = print_tabs(session, nesting);
3249 if (ret)
3250 return ret;
3251 ret = lttng_metadata_printf(session,
3252 "struct { } align(%u) _%s_padding;\n",
3253 array_type->alignment * CHAR_BIT,
3254 field->name);
3255 if (ret)
3256 return ret;
3257 }
3258 /*
3259 * Nested compound types: Only array of structures and variants are
3260 * currently supported.
3261 */
3262 elem_type = array_type->elem_type;
3263 switch (elem_type->type) {
3264 case lttng_kernel_type_integer:
3265 case lttng_kernel_type_struct:
3266 case lttng_kernel_type_variant:
3267 ret = _lttng_type_statedump(session, elem_type,
3268 array_type->encoding, nesting);
3269 if (ret)
3270 return ret;
3271 break;
3272
3273 default:
3274 return -EINVAL;
3275 }
3276 ret = lttng_metadata_printf(session,
3277 " _%s[%u];\n",
3278 field->name,
3279 array_type->length);
3280 return ret;
3281 }
3282
3283 /*
3284 * Must be called with sessions_mutex held.
3285 */
3286 static
3287 int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3288 const struct lttng_kernel_event_field *field,
3289 size_t nesting,
3290 const char *prev_field_name)
3291 {
3292 int ret;
3293 const char *length_name;
3294 const struct lttng_kernel_type_sequence *sequence_type;
3295 const struct lttng_kernel_type_common *elem_type;
3296
3297 sequence_type = lttng_kernel_get_type_sequence(field->type);
3298 WARN_ON_ONCE(!sequence_type);
3299
3300 length_name = sequence_type->length_name;
3301 if (!length_name)
3302 length_name = prev_field_name;
3303 if (!length_name)
3304 return -EINVAL;
3305
3306 if (sequence_type->alignment) {
3307 ret = print_tabs(session, nesting);
3308 if (ret)
3309 return ret;
3310 ret = lttng_metadata_printf(session,
3311 "struct { } align(%u) _%s_padding;\n",
3312 sequence_type->alignment * CHAR_BIT,
3313 field->name);
3314 if (ret)
3315 return ret;
3316 }
3317
3318 /*
3319 * Nested compound types: Only array of structures and variants are
3320 * currently supported.
3321 */
3322 elem_type = sequence_type->elem_type;
3323 switch (elem_type->type) {
3324 case lttng_kernel_type_integer:
3325 case lttng_kernel_type_struct:
3326 case lttng_kernel_type_variant:
3327 ret = _lttng_type_statedump(session, elem_type,
3328 sequence_type->encoding, nesting);
3329 if (ret)
3330 return ret;
3331 break;
3332
3333 default:
3334 return -EINVAL;
3335 }
3336 ret = lttng_metadata_printf(session,
3337 " _%s[ _%s ];\n",
3338 field->name,
3339 length_name);
3340 return ret;
3341 }
3342
3343 /*
3344 * Must be called with sessions_mutex held.
3345 */
3346 static
3347 int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3348 const struct lttng_kernel_type_enum *type,
3349 size_t nesting)
3350 {
3351 const struct lttng_kernel_enum_desc *enum_desc;
3352 const struct lttng_kernel_type_common *container_type;
3353 int ret;
3354 unsigned int i, nr_entries;
3355
3356 container_type = type->container_type;
3357 if (container_type->type != lttng_kernel_type_integer) {
3358 ret = -EINVAL;
3359 goto end;
3360 }
3361 enum_desc = type->desc;
3362 nr_entries = enum_desc->nr_entries;
3363
3364 ret = print_tabs(session, nesting);
3365 if (ret)
3366 goto end;
3367 ret = lttng_metadata_printf(session, "enum : ");
3368 if (ret)
3369 goto end;
3370 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3371 lttng_kernel_string_encoding_none, 0);
3372 if (ret)
3373 goto end;
3374 ret = lttng_metadata_printf(session, " {\n");
3375 if (ret)
3376 goto end;
3377 /* Dump all entries */
3378 for (i = 0; i < nr_entries; i++) {
3379 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3380 int j, len;
3381
3382 ret = print_tabs(session, nesting + 1);
3383 if (ret)
3384 goto end;
3385 ret = lttng_metadata_printf(session,
3386 "\"");
3387 if (ret)
3388 goto end;
3389 len = strlen(entry->string);
3390 /* Escape the character '"' */
3391 for (j = 0; j < len; j++) {
3392 char c = entry->string[j];
3393
3394 switch (c) {
3395 case '"':
3396 ret = lttng_metadata_printf(session,
3397 "\\\"");
3398 break;
3399 case '\\':
3400 ret = lttng_metadata_printf(session,
3401 "\\\\");
3402 break;
3403 default:
3404 ret = lttng_metadata_printf(session,
3405 "%c", c);
3406 break;
3407 }
3408 if (ret)
3409 goto end;
3410 }
3411 ret = lttng_metadata_printf(session, "\"");
3412 if (ret)
3413 goto end;
3414
3415 if (entry->options.is_auto) {
3416 ret = lttng_metadata_printf(session, ",\n");
3417 if (ret)
3418 goto end;
3419 } else {
3420 ret = lttng_metadata_printf(session,
3421 " = ");
3422 if (ret)
3423 goto end;
3424 if (entry->start.signedness)
3425 ret = lttng_metadata_printf(session,
3426 "%lld", (long long) entry->start.value);
3427 else
3428 ret = lttng_metadata_printf(session,
3429 "%llu", entry->start.value);
3430 if (ret)
3431 goto end;
3432 if (entry->start.signedness == entry->end.signedness &&
3433 entry->start.value
3434 == entry->end.value) {
3435 ret = lttng_metadata_printf(session,
3436 ",\n");
3437 } else {
3438 if (entry->end.signedness) {
3439 ret = lttng_metadata_printf(session,
3440 " ... %lld,\n",
3441 (long long) entry->end.value);
3442 } else {
3443 ret = lttng_metadata_printf(session,
3444 " ... %llu,\n",
3445 entry->end.value);
3446 }
3447 }
3448 if (ret)
3449 goto end;
3450 }
3451 }
3452 ret = print_tabs(session, nesting);
3453 if (ret)
3454 goto end;
3455 ret = lttng_metadata_printf(session, "}");
3456 end:
3457 return ret;
3458 }
3459
3460 /*
3461 * Must be called with sessions_mutex held.
3462 */
3463 static
3464 int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3465 const struct lttng_kernel_event_field *field,
3466 size_t nesting)
3467 {
3468 int ret;
3469 const struct lttng_kernel_type_enum *enum_type;
3470
3471 enum_type = lttng_kernel_get_type_enum(field->type);
3472 WARN_ON_ONCE(!enum_type);
3473 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3474 if (ret)
3475 return ret;
3476 return lttng_field_name_statedump(session, field, nesting);
3477 }
3478
3479 static
3480 int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3481 const struct lttng_kernel_event_field *field,
3482 size_t nesting)
3483 {
3484 int ret;
3485
3486 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3487 lttng_kernel_string_encoding_none, nesting);
3488 if (ret)
3489 return ret;
3490 return lttng_field_name_statedump(session, field, nesting);
3491 }
3492
3493 static
3494 int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3495 const struct lttng_kernel_type_string *type,
3496 size_t nesting)
3497 {
3498 int ret;
3499
3500 /* Default encoding is UTF8 */
3501 ret = print_tabs(session, nesting);
3502 if (ret)
3503 return ret;
3504 ret = lttng_metadata_printf(session,
3505 "string%s",
3506 type->encoding == lttng_kernel_string_encoding_ASCII ?
3507 " { encoding = ASCII; }" : "");
3508 return ret;
3509 }
3510
3511 static
3512 int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3513 const struct lttng_kernel_event_field *field,
3514 size_t nesting)
3515 {
3516 const struct lttng_kernel_type_string *string_type;
3517 int ret;
3518
3519 string_type = lttng_kernel_get_type_string(field->type);
3520 WARN_ON_ONCE(!string_type);
3521 ret = _lttng_string_type_statedump(session, string_type, nesting);
3522 if (ret)
3523 return ret;
3524 return lttng_field_name_statedump(session, field, nesting);
3525 }
3526
3527 /*
3528 * Must be called with sessions_mutex held.
3529 */
3530 static
3531 int _lttng_type_statedump(struct lttng_kernel_session *session,
3532 const struct lttng_kernel_type_common *type,
3533 enum lttng_kernel_string_encoding parent_encoding,
3534 size_t nesting)
3535 {
3536 int ret = 0;
3537
3538 switch (type->type) {
3539 case lttng_kernel_type_integer:
3540 ret = _lttng_integer_type_statedump(session,
3541 lttng_kernel_get_type_integer(type),
3542 parent_encoding, nesting);
3543 break;
3544 case lttng_kernel_type_enum:
3545 ret = _lttng_enum_type_statedump(session,
3546 lttng_kernel_get_type_enum(type),
3547 nesting);
3548 break;
3549 case lttng_kernel_type_string:
3550 ret = _lttng_string_type_statedump(session,
3551 lttng_kernel_get_type_string(type),
3552 nesting);
3553 break;
3554 case lttng_kernel_type_struct:
3555 ret = _lttng_struct_type_statedump(session,
3556 lttng_kernel_get_type_struct(type),
3557 nesting);
3558 break;
3559 case lttng_kernel_type_variant:
3560 ret = _lttng_variant_type_statedump(session,
3561 lttng_kernel_get_type_variant(type),
3562 nesting, NULL);
3563 break;
3564
3565 /* Nested arrays and sequences are not supported yet. */
3566 case lttng_kernel_type_array:
3567 case lttng_kernel_type_sequence:
3568 default:
3569 WARN_ON_ONCE(1);
3570 return -EINVAL;
3571 }
3572 return ret;
3573 }
3574
3575 /*
3576 * Must be called with sessions_mutex held.
3577 */
3578 static
3579 int _lttng_field_statedump(struct lttng_kernel_session *session,
3580 const struct lttng_kernel_event_field *field,
3581 size_t nesting,
3582 const char **prev_field_name_p)
3583 {
3584 const char *prev_field_name = NULL;
3585 int ret = 0;
3586
3587 if (prev_field_name_p)
3588 prev_field_name = *prev_field_name_p;
3589 switch (field->type->type) {
3590 case lttng_kernel_type_integer:
3591 ret = _lttng_integer_field_statedump(session, field, nesting);
3592 break;
3593 case lttng_kernel_type_enum:
3594 ret = _lttng_enum_field_statedump(session, field, nesting);
3595 break;
3596 case lttng_kernel_type_string:
3597 ret = _lttng_string_field_statedump(session, field, nesting);
3598 break;
3599 case lttng_kernel_type_struct:
3600 ret = _lttng_struct_field_statedump(session, field, nesting);
3601 break;
3602 case lttng_kernel_type_array:
3603 ret = _lttng_array_field_statedump(session, field, nesting);
3604 break;
3605 case lttng_kernel_type_sequence:
3606 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3607 break;
3608 case lttng_kernel_type_variant:
3609 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3610 break;
3611
3612 default:
3613 WARN_ON_ONCE(1);
3614 return -EINVAL;
3615 }
3616 if (prev_field_name_p)
3617 *prev_field_name_p = field->name;
3618 return ret;
3619 }
3620
3621 static
3622 int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3623 struct lttng_kernel_ctx *ctx)
3624 {
3625 const char *prev_field_name = NULL;
3626 int ret = 0;
3627 int i;
3628
3629 if (!ctx)
3630 return 0;
3631 for (i = 0; i < ctx->nr_fields; i++) {
3632 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3633
3634 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3635 if (ret)
3636 return ret;
3637 }
3638 return ret;
3639 }
3640
3641 static
3642 int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3643 struct lttng_kernel_event_recorder *event_recorder)
3644 {
3645 const char *prev_field_name = NULL;
3646 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3647 int ret = 0;
3648 int i;
3649
3650 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3651 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3652
3653 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3654 if (ret)
3655 return ret;
3656 }
3657 return ret;
3658 }
3659
3660 /*
3661 * Must be called with sessions_mutex held.
3662 * The entire event metadata is printed as a single atomic metadata
3663 * transaction.
3664 */
3665 static
3666 int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
3667 struct lttng_kernel_channel_buffer *chan,
3668 struct lttng_kernel_event_recorder *event_recorder)
3669 {
3670 int ret = 0;
3671
3672 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3673 return 0;
3674 if (chan->priv->channel_type == METADATA_CHANNEL)
3675 return 0;
3676
3677 lttng_metadata_begin(session);
3678
3679 ret = lttng_metadata_printf(session,
3680 "event {\n"
3681 " name = \"%s\";\n"
3682 " id = %u;\n"
3683 " stream_id = %u;\n",
3684 event_recorder->priv->parent.desc->event_name,
3685 event_recorder->priv->id,
3686 event_recorder->chan->priv->id);
3687 if (ret)
3688 goto end;
3689
3690 ret = lttng_metadata_printf(session,
3691 " fields := struct {\n"
3692 );
3693 if (ret)
3694 goto end;
3695
3696 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3697 if (ret)
3698 goto end;
3699
3700 /*
3701 * LTTng space reservation can only reserve multiples of the
3702 * byte size.
3703 */
3704 ret = lttng_metadata_printf(session,
3705 " };\n"
3706 "};\n\n");
3707 if (ret)
3708 goto end;
3709
3710 event_recorder->priv->metadata_dumped = 1;
3711 end:
3712 lttng_metadata_end(session);
3713 return ret;
3714
3715 }
3716
3717 /*
3718 * Must be called with sessions_mutex held.
3719 * The entire channel metadata is printed as a single atomic metadata
3720 * transaction.
3721 */
3722 static
3723 int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3724 struct lttng_kernel_channel_buffer *chan)
3725 {
3726 int ret = 0;
3727
3728 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3729 return 0;
3730
3731 if (chan->priv->channel_type == METADATA_CHANNEL)
3732 return 0;
3733
3734 lttng_metadata_begin(session);
3735
3736 WARN_ON_ONCE(!chan->priv->header_type);
3737 ret = lttng_metadata_printf(session,
3738 "stream {\n"
3739 " id = %u;\n"
3740 " event.header := %s;\n"
3741 " packet.context := struct packet_context;\n",
3742 chan->priv->id,
3743 chan->priv->header_type == 1 ? "struct event_header_compact" :
3744 "struct event_header_large");
3745 if (ret)
3746 goto end;
3747
3748 if (chan->priv->ctx) {
3749 ret = lttng_metadata_printf(session,
3750 " event.context := struct {\n");
3751 if (ret)
3752 goto end;
3753 }
3754 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3755 if (ret)
3756 goto end;
3757 if (chan->priv->ctx) {
3758 ret = lttng_metadata_printf(session,
3759 " };\n");
3760 if (ret)
3761 goto end;
3762 }
3763
3764 ret = lttng_metadata_printf(session,
3765 "};\n\n");
3766
3767 chan->priv->metadata_dumped = 1;
3768 end:
3769 lttng_metadata_end(session);
3770 return ret;
3771 }
3772
3773 /*
3774 * Must be called with sessions_mutex held.
3775 */
3776 static
3777 int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3778 {
3779 return lttng_metadata_printf(session,
3780 "struct packet_context {\n"
3781 " uint64_clock_monotonic_t timestamp_begin;\n"
3782 " uint64_clock_monotonic_t timestamp_end;\n"
3783 " uint64_t content_size;\n"
3784 " uint64_t packet_size;\n"
3785 " uint64_t packet_seq_num;\n"
3786 " unsigned long events_discarded;\n"
3787 " uint32_t cpu_id;\n"
3788 "};\n\n"
3789 );
3790 }
3791
3792 /*
3793 * Compact header:
3794 * id: range: 0 - 30.
3795 * id 31 is reserved to indicate an extended header.
3796 *
3797 * Large header:
3798 * id: range: 0 - 65534.
3799 * id 65535 is reserved to indicate an extended header.
3800 *
3801 * Must be called with sessions_mutex held.
3802 */
3803 static
3804 int _lttng_event_header_declare(struct lttng_kernel_session *session)
3805 {
3806 return lttng_metadata_printf(session,
3807 "struct event_header_compact {\n"
3808 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3809 " variant <id> {\n"
3810 " struct {\n"
3811 " uint27_clock_monotonic_t timestamp;\n"
3812 " } compact;\n"
3813 " struct {\n"
3814 " uint32_t id;\n"
3815 " uint64_clock_monotonic_t timestamp;\n"
3816 " } extended;\n"
3817 " } v;\n"
3818 "} align(%u);\n"
3819 "\n"
3820 "struct event_header_large {\n"
3821 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3822 " variant <id> {\n"
3823 " struct {\n"
3824 " uint32_clock_monotonic_t timestamp;\n"
3825 " } compact;\n"
3826 " struct {\n"
3827 " uint32_t id;\n"
3828 " uint64_clock_monotonic_t timestamp;\n"
3829 " } extended;\n"
3830 " } v;\n"
3831 "} align(%u);\n\n",
3832 lttng_alignof(uint32_t) * CHAR_BIT,
3833 lttng_alignof(uint16_t) * CHAR_BIT
3834 );
3835 }
3836
3837 /*
3838 * Approximation of NTP time of day to clock monotonic correlation,
3839 * taken at start of trace.
3840 * Yes, this is only an approximation. Yes, we can (and will) do better
3841 * in future versions.
3842 * This function may return a negative offset. It may happen if the
3843 * system sets the REALTIME clock to 0 after boot.
3844 *
3845 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3846 * y2038 compliant.
3847 */
3848 static
3849 int64_t measure_clock_offset(void)
3850 {
3851 uint64_t monotonic_avg, monotonic[2], realtime;
3852 uint64_t tcf = trace_clock_freq();
3853 int64_t offset;
3854 unsigned long flags;
3855 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3856 struct timespec64 rts = { 0, 0 };
3857 #else
3858 struct timespec rts = { 0, 0 };
3859 #endif
3860
3861 /* Disable interrupts to increase correlation precision. */
3862 local_irq_save(flags);
3863 monotonic[0] = trace_clock_read64();
3864 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3865 ktime_get_real_ts64(&rts);
3866 #else
3867 getnstimeofday(&rts);
3868 #endif
3869 monotonic[1] = trace_clock_read64();
3870 local_irq_restore(flags);
3871
3872 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3873 realtime = (uint64_t) rts.tv_sec * tcf;
3874 if (tcf == NSEC_PER_SEC) {
3875 realtime += rts.tv_nsec;
3876 } else {
3877 uint64_t n = rts.tv_nsec * tcf;
3878
3879 do_div(n, NSEC_PER_SEC);
3880 realtime += n;
3881 }
3882 offset = (int64_t) realtime - monotonic_avg;
3883 return offset;
3884 }
3885
3886 static
3887 int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3888 {
3889 int ret = 0;
3890 size_t i;
3891 char cur;
3892
3893 i = 0;
3894 cur = string[i];
3895 while (cur != '\0') {
3896 switch (cur) {
3897 case '\n':
3898 ret = lttng_metadata_printf(session, "%s", "\\n");
3899 break;
3900 case '\\':
3901 case '"':
3902 ret = lttng_metadata_printf(session, "%c", '\\');
3903 if (ret)
3904 goto error;
3905 /* We still print the current char */
3906 lttng_fallthrough;
3907 default:
3908 ret = lttng_metadata_printf(session, "%c", cur);
3909 break;
3910 }
3911
3912 if (ret)
3913 goto error;
3914
3915 cur = string[++i];
3916 }
3917 error:
3918 return ret;
3919 }
3920
3921 static
3922 int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3923 const char *field_value)
3924 {
3925 int ret;
3926
3927 ret = lttng_metadata_printf(session, " %s = \"", field);
3928 if (ret)
3929 goto error;
3930
3931 ret = print_escaped_ctf_string(session, field_value);
3932 if (ret)
3933 goto error;
3934
3935 ret = lttng_metadata_printf(session, "\";\n");
3936
3937 error:
3938 return ret;
3939 }
3940
3941 /*
3942 * Output metadata into this session's metadata buffers.
3943 * Must be called with sessions_mutex held.
3944 */
3945 static
3946 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3947 {
3948 unsigned char *uuid_c = session->priv->uuid.b;
3949 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3950 const char *product_uuid;
3951 struct lttng_kernel_channel_buffer_private *chan_priv;
3952 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3953 int ret = 0;
3954
3955 if (!LTTNG_READ_ONCE(session->active))
3956 return 0;
3957
3958 lttng_metadata_begin(session);
3959
3960 if (session->priv->metadata_dumped)
3961 goto skip_session;
3962
3963 snprintf(uuid_s, sizeof(uuid_s),
3964 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3965 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3966 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3967 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3968 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3969
3970 ret = lttng_metadata_printf(session,
3971 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3972 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3973 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3974 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3975 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3976 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3977 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3978 "\n"
3979 "trace {\n"
3980 " major = %u;\n"
3981 " minor = %u;\n"
3982 " uuid = \"%s\";\n"
3983 " byte_order = %s;\n"
3984 " packet.header := struct {\n"
3985 " uint32_t magic;\n"
3986 " uint8_t uuid[16];\n"
3987 " uint32_t stream_id;\n"
3988 " uint64_t stream_instance_id;\n"
3989 " };\n"
3990 "};\n\n",
3991 lttng_alignof(uint8_t) * CHAR_BIT,
3992 lttng_alignof(uint16_t) * CHAR_BIT,
3993 lttng_alignof(uint32_t) * CHAR_BIT,
3994 lttng_alignof(uint64_t) * CHAR_BIT,
3995 sizeof(unsigned long) * CHAR_BIT,
3996 lttng_alignof(unsigned long) * CHAR_BIT,
3997 CTF_SPEC_MAJOR,
3998 CTF_SPEC_MINOR,
3999 uuid_s,
4000 #if __BYTE_ORDER == __BIG_ENDIAN
4001 "be"
4002 #else
4003 "le"
4004 #endif
4005 );
4006 if (ret)
4007 goto end;
4008
4009 ret = lttng_metadata_printf(session,
4010 "env {\n"
4011 " hostname = \"%s\";\n"
4012 " domain = \"kernel\";\n"
4013 " sysname = \"%s\";\n"
4014 " kernel_release = \"%s\";\n"
4015 " kernel_version = \"%s\";\n"
4016 " tracer_name = \"lttng-modules\";\n"
4017 " tracer_major = %d;\n"
4018 " tracer_minor = %d;\n"
4019 " tracer_patchlevel = %d;\n"
4020 " trace_buffering_scheme = \"global\";\n",
4021 current->nsproxy->uts_ns->name.nodename,
4022 utsname()->sysname,
4023 utsname()->release,
4024 utsname()->version,
4025 LTTNG_MODULES_MAJOR_VERSION,
4026 LTTNG_MODULES_MINOR_VERSION,
4027 LTTNG_MODULES_PATCHLEVEL_VERSION
4028 );
4029 if (ret)
4030 goto end;
4031
4032 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
4033 if (ret)
4034 goto end;
4035 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
4036 session->priv->creation_time);
4037 if (ret)
4038 goto end;
4039
4040 /* Add the product UUID to the 'env' section */
4041 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
4042 if (product_uuid) {
4043 ret = lttng_metadata_printf(session,
4044 " product_uuid = \"%s\";\n",
4045 product_uuid
4046 );
4047 if (ret)
4048 goto end;
4049 }
4050
4051 /* Close the 'env' section */
4052 ret = lttng_metadata_printf(session, "};\n\n");
4053 if (ret)
4054 goto end;
4055
4056 ret = lttng_metadata_printf(session,
4057 "clock {\n"
4058 " name = \"%s\";\n",
4059 trace_clock_name()
4060 );
4061 if (ret)
4062 goto end;
4063
4064 if (!trace_clock_uuid(clock_uuid_s)) {
4065 ret = lttng_metadata_printf(session,
4066 " uuid = \"%s\";\n",
4067 clock_uuid_s
4068 );
4069 if (ret)
4070 goto end;
4071 }
4072
4073 ret = lttng_metadata_printf(session,
4074 " description = \"%s\";\n"
4075 " freq = %llu; /* Frequency, in Hz */\n"
4076 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
4077 " offset = %lld;\n"
4078 "};\n\n",
4079 trace_clock_description(),
4080 (unsigned long long) trace_clock_freq(),
4081 (long long) measure_clock_offset()
4082 );
4083 if (ret)
4084 goto end;
4085
4086 ret = lttng_metadata_printf(session,
4087 "typealias integer {\n"
4088 " size = 27; align = 1; signed = false;\n"
4089 " map = clock.%s.value;\n"
4090 "} := uint27_clock_monotonic_t;\n"
4091 "\n"
4092 "typealias integer {\n"
4093 " size = 32; align = %u; signed = false;\n"
4094 " map = clock.%s.value;\n"
4095 "} := uint32_clock_monotonic_t;\n"
4096 "\n"
4097 "typealias integer {\n"
4098 " size = 64; align = %u; signed = false;\n"
4099 " map = clock.%s.value;\n"
4100 "} := uint64_clock_monotonic_t;\n\n",
4101 trace_clock_name(),
4102 lttng_alignof(uint32_t) * CHAR_BIT,
4103 trace_clock_name(),
4104 lttng_alignof(uint64_t) * CHAR_BIT,
4105 trace_clock_name()
4106 );
4107 if (ret)
4108 goto end;
4109
4110 ret = _lttng_stream_packet_context_declare(session);
4111 if (ret)
4112 goto end;
4113
4114 ret = _lttng_event_header_declare(session);
4115 if (ret)
4116 goto end;
4117
4118 skip_session:
4119 list_for_each_entry(chan_priv, &session->priv->chan, node) {
4120 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
4121 if (ret)
4122 goto end;
4123 }
4124
4125 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
4126 ret = _lttng_event_metadata_statedump(session, event_recorder_priv->pub->chan,
4127 event_recorder_priv->pub);
4128 if (ret)
4129 goto end;
4130 }
4131 session->priv->metadata_dumped = 1;
4132 end:
4133 lttng_metadata_end(session);
4134 return ret;
4135 }
4136
4137 /**
4138 * lttng_transport_register - LTT transport registration
4139 * @transport: transport structure
4140 *
4141 * Registers a transport which can be used as output to extract the data out of
4142 * LTTng. The module calling this registration function must ensure that no
4143 * trap-inducing code will be executed by the transport functions. E.g.
4144 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
4145 * is made visible to the transport function. This registration acts as a
4146 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
4147 * after its registration must it synchronize the TLBs.
4148 */
4149 void lttng_transport_register(struct lttng_transport *transport)
4150 {
4151 /*
4152 * Make sure no page fault can be triggered by the module about to be
4153 * registered. We deal with this here so we don't have to call
4154 * vmalloc_sync_mappings() in each module's init.
4155 */
4156 wrapper_vmalloc_sync_mappings();
4157
4158 mutex_lock(&sessions_mutex);
4159 list_add_tail(&transport->node, &lttng_transport_list);
4160 mutex_unlock(&sessions_mutex);
4161 }
4162 EXPORT_SYMBOL_GPL(lttng_transport_register);
4163
4164 /**
4165 * lttng_transport_unregister - LTT transport unregistration
4166 * @transport: transport structure
4167 */
4168 void lttng_transport_unregister(struct lttng_transport *transport)
4169 {
4170 mutex_lock(&sessions_mutex);
4171 list_del(&transport->node);
4172 mutex_unlock(&sessions_mutex);
4173 }
4174 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4175
4176 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4177 {
4178 /*
4179 * Make sure no page fault can be triggered by the module about to be
4180 * registered. We deal with this here so we don't have to call
4181 * vmalloc_sync_mappings() in each module's init.
4182 */
4183 wrapper_vmalloc_sync_mappings();
4184
4185 mutex_lock(&sessions_mutex);
4186 list_add_tail(&transport->node, &lttng_counter_transport_list);
4187 mutex_unlock(&sessions_mutex);
4188 }
4189 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4190
4191 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4192 {
4193 mutex_lock(&sessions_mutex);
4194 list_del(&transport->node);
4195 mutex_unlock(&sessions_mutex);
4196 }
4197 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4198
4199 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4200
4201 enum cpuhp_state lttng_hp_prepare;
4202 enum cpuhp_state lttng_hp_online;
4203
4204 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4205 {
4206 struct lttng_cpuhp_node *lttng_node;
4207
4208 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4209 switch (lttng_node->component) {
4210 case LTTNG_RING_BUFFER_FRONTEND:
4211 return 0;
4212 case LTTNG_RING_BUFFER_BACKEND:
4213 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4214 case LTTNG_RING_BUFFER_ITER:
4215 return 0;
4216 case LTTNG_CONTEXT_PERF_COUNTERS:
4217 return 0;
4218 default:
4219 return -EINVAL;
4220 }
4221 }
4222
4223 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4224 {
4225 struct lttng_cpuhp_node *lttng_node;
4226
4227 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4228 switch (lttng_node->component) {
4229 case LTTNG_RING_BUFFER_FRONTEND:
4230 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4231 case LTTNG_RING_BUFFER_BACKEND:
4232 return 0;
4233 case LTTNG_RING_BUFFER_ITER:
4234 return 0;
4235 case LTTNG_CONTEXT_PERF_COUNTERS:
4236 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4237 default:
4238 return -EINVAL;
4239 }
4240 }
4241
4242 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4243 {
4244 struct lttng_cpuhp_node *lttng_node;
4245
4246 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4247 switch (lttng_node->component) {
4248 case LTTNG_RING_BUFFER_FRONTEND:
4249 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4250 case LTTNG_RING_BUFFER_BACKEND:
4251 return 0;
4252 case LTTNG_RING_BUFFER_ITER:
4253 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4254 case LTTNG_CONTEXT_PERF_COUNTERS:
4255 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4256 default:
4257 return -EINVAL;
4258 }
4259 }
4260
4261 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4262 {
4263 struct lttng_cpuhp_node *lttng_node;
4264
4265 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4266 switch (lttng_node->component) {
4267 case LTTNG_RING_BUFFER_FRONTEND:
4268 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4269 case LTTNG_RING_BUFFER_BACKEND:
4270 return 0;
4271 case LTTNG_RING_BUFFER_ITER:
4272 return 0;
4273 case LTTNG_CONTEXT_PERF_COUNTERS:
4274 return 0;
4275 default:
4276 return -EINVAL;
4277 }
4278 }
4279
4280 static int __init lttng_init_cpu_hotplug(void)
4281 {
4282 int ret;
4283
4284 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4285 lttng_hotplug_prepare,
4286 lttng_hotplug_dead);
4287 if (ret < 0) {
4288 return ret;
4289 }
4290 lttng_hp_prepare = ret;
4291 lttng_rb_set_hp_prepare(ret);
4292
4293 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4294 lttng_hotplug_online,
4295 lttng_hotplug_offline);
4296 if (ret < 0) {
4297 cpuhp_remove_multi_state(lttng_hp_prepare);
4298 lttng_hp_prepare = 0;
4299 return ret;
4300 }
4301 lttng_hp_online = ret;
4302 lttng_rb_set_hp_online(ret);
4303
4304 return 0;
4305 }
4306
4307 static void __exit lttng_exit_cpu_hotplug(void)
4308 {
4309 lttng_rb_set_hp_online(0);
4310 cpuhp_remove_multi_state(lttng_hp_online);
4311 lttng_rb_set_hp_prepare(0);
4312 cpuhp_remove_multi_state(lttng_hp_prepare);
4313 }
4314
4315 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4316 static int lttng_init_cpu_hotplug(void)
4317 {
4318 return 0;
4319 }
4320 static void lttng_exit_cpu_hotplug(void)
4321 {
4322 }
4323 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4324
4325 static int __init lttng_events_init(void)
4326 {
4327 int ret;
4328
4329 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4330 if (ret)
4331 return ret;
4332 ret = wrapper_get_pfnblock_flags_mask_init();
4333 if (ret)
4334 return ret;
4335 ret = wrapper_get_pageblock_flags_mask_init();
4336 if (ret)
4337 return ret;
4338 ret = lttng_probes_init();
4339 if (ret)
4340 return ret;
4341 ret = lttng_context_init();
4342 if (ret)
4343 return ret;
4344 ret = lttng_tracepoint_init();
4345 if (ret)
4346 goto error_tp;
4347 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4348 if (!event_recorder_cache) {
4349 ret = -ENOMEM;
4350 goto error_kmem_event_recorder;
4351 }
4352 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4353 if (!event_recorder_private_cache) {
4354 ret = -ENOMEM;
4355 goto error_kmem_event_recorder_private;
4356 }
4357 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4358 if (!event_notifier_cache) {
4359 ret = -ENOMEM;
4360 goto error_kmem_event_notifier;
4361 }
4362 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4363 if (!event_notifier_private_cache) {
4364 ret = -ENOMEM;
4365 goto error_kmem_event_notifier_private;
4366 }
4367 ret = lttng_abi_init();
4368 if (ret)
4369 goto error_abi;
4370 ret = lttng_logger_init();
4371 if (ret)
4372 goto error_logger;
4373 ret = lttng_init_cpu_hotplug();
4374 if (ret)
4375 goto error_hotplug;
4376 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4377 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4378 __stringify(LTTNG_MODULES_MINOR_VERSION),
4379 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4380 LTTNG_MODULES_EXTRAVERSION,
4381 LTTNG_VERSION_NAME,
4382 #ifdef LTTNG_EXTRA_VERSION_GIT
4383 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4384 #else
4385 "",
4386 #endif
4387 #ifdef LTTNG_EXTRA_VERSION_NAME
4388 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4389 #else
4390 "");
4391 #endif
4392 #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
4393 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
4394 #endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
4395 return 0;
4396
4397 error_hotplug:
4398 lttng_logger_exit();
4399 error_logger:
4400 lttng_abi_exit();
4401 error_abi:
4402 kmem_cache_destroy(event_notifier_private_cache);
4403 error_kmem_event_notifier_private:
4404 kmem_cache_destroy(event_notifier_cache);
4405 error_kmem_event_notifier:
4406 kmem_cache_destroy(event_recorder_private_cache);
4407 error_kmem_event_recorder_private:
4408 kmem_cache_destroy(event_recorder_cache);
4409 error_kmem_event_recorder:
4410 lttng_tracepoint_exit();
4411 error_tp:
4412 lttng_context_exit();
4413 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4414 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4415 __stringify(LTTNG_MODULES_MINOR_VERSION),
4416 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4417 LTTNG_MODULES_EXTRAVERSION,
4418 LTTNG_VERSION_NAME,
4419 #ifdef LTTNG_EXTRA_VERSION_GIT
4420 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4421 #else
4422 "",
4423 #endif
4424 #ifdef LTTNG_EXTRA_VERSION_NAME
4425 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4426 #else
4427 "");
4428 #endif
4429 return ret;
4430 }
4431
4432 module_init(lttng_events_init);
4433
4434 static void __exit lttng_events_exit(void)
4435 {
4436 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4437
4438 lttng_exit_cpu_hotplug();
4439 lttng_logger_exit();
4440 lttng_abi_exit();
4441 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4442 lttng_session_destroy(session_priv->pub);
4443 kmem_cache_destroy(event_recorder_cache);
4444 kmem_cache_destroy(event_recorder_private_cache);
4445 kmem_cache_destroy(event_notifier_cache);
4446 kmem_cache_destroy(event_notifier_private_cache);
4447 lttng_tracepoint_exit();
4448 lttng_context_exit();
4449 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4450 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4451 __stringify(LTTNG_MODULES_MINOR_VERSION),
4452 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4453 LTTNG_MODULES_EXTRAVERSION,
4454 LTTNG_VERSION_NAME,
4455 #ifdef LTTNG_EXTRA_VERSION_GIT
4456 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4457 #else
4458 "",
4459 #endif
4460 #ifdef LTTNG_EXTRA_VERSION_NAME
4461 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4462 #else
4463 "");
4464 #endif
4465 }
4466
4467 module_exit(lttng_events_exit);
4468
4469 #include <generated/patches.h>
4470 #ifdef LTTNG_EXTRA_VERSION_GIT
4471 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4472 #endif
4473 #ifdef LTTNG_EXTRA_VERSION_NAME
4474 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4475 #endif
4476 MODULE_LICENSE("GPL and additional rights");
4477 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4478 MODULE_DESCRIPTION("LTTng tracer");
4479 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4480 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4481 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4482 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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