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