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Refactoring: introduce lttng_event_sync_filter_state and lttng_event_sync_capture_state
[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, parent.node) {
366 ret = _lttng_event_unregister(&event_recorder_priv->pub->parent);
367 WARN_ON(ret);
368 }
369 synchronize_trace(); /* Wait for in-flight events to complete */
370 list_for_each_entry(chan_priv, &session->priv->chan, node) {
371 ret = lttng_syscalls_destroy_syscall_table(&chan_priv->parent.syscall_table);
372 WARN_ON(ret);
373 }
374 list_for_each_entry_safe(event_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, parent.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, parent.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, parent.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, parent.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->parent.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->parent.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->parent.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->parent.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->parent.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 static
2226 void lttng_event_enabler_init_event_filter(struct lttng_event_enabler_common *event_enabler,
2227 struct lttng_kernel_event_common *event)
2228 {
2229 /* Link filter bytecodes if not linked yet. */
2230 lttng_enabler_link_bytecode(event->priv->desc, lttng_static_ctx,
2231 &event->priv->filter_bytecode_runtime_head, &event_enabler->filter_bytecode_head);
2232 }
2233
2234 static
2235 void lttng_event_enabler_init_event_capture(struct lttng_event_enabler_common *event_enabler,
2236 struct lttng_kernel_event_common *event)
2237 {
2238 switch (event_enabler->enabler_type) {
2239 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2240 break;
2241 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2242 {
2243 struct lttng_event_notifier_enabler *event_notifier_enabler =
2244 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2245 struct lttng_kernel_event_notifier *event_notifier =
2246 container_of(event, struct lttng_kernel_event_notifier, parent);
2247
2248 /* Link capture bytecodes if not linked yet. */
2249 lttng_enabler_link_bytecode(event->priv->desc,
2250 lttng_static_ctx, &event_notifier->priv->capture_bytecode_runtime_head,
2251 &event_notifier_enabler->capture_bytecode_head);
2252 event_notifier->priv->num_captures = event_notifier_enabler->num_captures;
2253 break;
2254 }
2255 default:
2256 WARN_ON_ONCE(1);
2257 }
2258 }
2259
2260 /*
2261 * Create events associated with an event_enabler (if not already present),
2262 * and add backward reference from the event to the enabler.
2263 * Should be called with sessions mutex held.
2264 */
2265 static
2266 int lttng_event_enabler_ref_events(struct lttng_event_enabler_common *event_enabler)
2267 {
2268 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(event_enabler);
2269 struct lttng_kernel_event_common_private *event_priv;
2270
2271 lttng_syscall_table_set_wildcard_all(event_enabler);
2272
2273 /* First ensure that probe events are created for this enabler. */
2274 lttng_create_event_if_missing(event_enabler);
2275
2276 /* Link the created event with its associated enabler. */
2277 list_for_each_entry(event_priv, event_list_head, node) {
2278 struct lttng_kernel_event_common *event = event_priv->pub;
2279 struct lttng_enabler_ref *enabler_ref;
2280
2281 if (!lttng_event_enabler_match_event(event_enabler, event))
2282 continue;
2283
2284 enabler_ref = lttng_enabler_ref(&event_priv->enablers_ref_head, event_enabler);
2285 if (!enabler_ref) {
2286 /*
2287 * If no backward ref, create it.
2288 * Add backward ref from event_notifier to enabler.
2289 */
2290 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2291 if (!enabler_ref)
2292 return -ENOMEM;
2293
2294 enabler_ref->ref = event_enabler;
2295 list_add(&enabler_ref->node, &event_priv->enablers_ref_head);
2296 }
2297
2298 lttng_event_enabler_init_event_filter(event_enabler, event);
2299 lttng_event_enabler_init_event_capture(event_enabler, event);
2300 }
2301 return 0;
2302 }
2303
2304 /*
2305 * Called at module load: connect the probe on all enablers matching
2306 * this event.
2307 * Called with sessions lock held.
2308 */
2309 int lttng_fix_pending_events(void)
2310 {
2311 struct lttng_kernel_session_private *session_priv;
2312
2313 list_for_each_entry(session_priv, &sessions, list)
2314 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2315 return 0;
2316 }
2317
2318 static bool lttng_event_notifier_group_has_active_event_notifiers(
2319 struct lttng_event_notifier_group *event_notifier_group)
2320 {
2321 struct lttng_event_notifier_enabler *event_notifier_enabler;
2322
2323 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2324 node) {
2325 if (event_notifier_enabler->parent.enabled)
2326 return true;
2327 }
2328 return false;
2329 }
2330
2331 bool lttng_event_notifier_active(void)
2332 {
2333 struct lttng_event_notifier_group *event_notifier_group;
2334
2335 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2336 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2337 return true;
2338 }
2339 return false;
2340 }
2341
2342 int lttng_fix_pending_event_notifiers(void)
2343 {
2344 struct lttng_event_notifier_group *event_notifier_group;
2345
2346 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2347 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2348 return 0;
2349 }
2350
2351 struct lttng_event_recorder_enabler *lttng_event_recorder_enabler_create(
2352 enum lttng_enabler_format_type format_type,
2353 struct lttng_kernel_abi_event *event_param,
2354 struct lttng_kernel_channel_buffer *chan)
2355 {
2356 struct lttng_event_recorder_enabler *event_enabler;
2357
2358 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2359 if (!event_enabler)
2360 return NULL;
2361 event_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_RECORDER;
2362 event_enabler->parent.format_type = format_type;
2363 INIT_LIST_HEAD(&event_enabler->parent.filter_bytecode_head);
2364 memcpy(&event_enabler->parent.event_param, event_param,
2365 sizeof(event_enabler->parent.event_param));
2366 event_enabler->chan = chan;
2367 /* ctx left NULL */
2368 event_enabler->parent.enabled = 0;
2369 return event_enabler;
2370 }
2371
2372 void lttng_event_enabler_session_add(struct lttng_kernel_session *session,
2373 struct lttng_event_recorder_enabler *event_enabler)
2374 {
2375 mutex_lock(&sessions_mutex);
2376 list_add(&event_enabler->node, &session->priv->enablers_head);
2377 event_enabler->published = true;
2378 lttng_session_lazy_sync_event_enablers(session);
2379 mutex_unlock(&sessions_mutex);
2380 }
2381
2382 int lttng_event_enabler_enable(struct lttng_event_enabler_common *event_enabler)
2383 {
2384 mutex_lock(&sessions_mutex);
2385 event_enabler->enabled = 1;
2386 lttng_event_enabler_sync(event_enabler);
2387 mutex_unlock(&sessions_mutex);
2388 return 0;
2389 }
2390
2391 int lttng_event_enabler_disable(struct lttng_event_enabler_common *event_enabler)
2392 {
2393 mutex_lock(&sessions_mutex);
2394 event_enabler->enabled = 0;
2395 lttng_event_enabler_sync(event_enabler);
2396 mutex_unlock(&sessions_mutex);
2397 return 0;
2398 }
2399
2400 static
2401 int lttng_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *enabler,
2402 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2403 {
2404 struct lttng_kernel_bytecode_node *bytecode_node;
2405 uint32_t bytecode_len;
2406 int ret;
2407
2408 ret = get_user(bytecode_len, &bytecode->len);
2409 if (ret)
2410 return ret;
2411 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2412 GFP_KERNEL);
2413 if (!bytecode_node)
2414 return -ENOMEM;
2415 ret = copy_from_user(&bytecode_node->bc, bytecode,
2416 sizeof(*bytecode) + bytecode_len);
2417 if (ret)
2418 goto error_free;
2419
2420 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2421 bytecode_node->enabler = enabler;
2422 /* Enforce length based on allocated size */
2423 bytecode_node->bc.len = bytecode_len;
2424 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2425
2426 return 0;
2427
2428 error_free:
2429 lttng_kvfree(bytecode_node);
2430 return ret;
2431 }
2432
2433 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *event_enabler,
2434 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2435 {
2436 int ret;
2437 ret = lttng_enabler_attach_filter_bytecode(event_enabler, bytecode);
2438 if (ret)
2439 goto error;
2440 lttng_event_enabler_sync(event_enabler);
2441 return 0;
2442
2443 error:
2444 return ret;
2445 }
2446
2447 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2448 struct lttng_kernel_abi_event_callsite __user *callsite)
2449 {
2450
2451 switch (event->priv->instrumentation) {
2452 case LTTNG_KERNEL_ABI_UPROBE:
2453 return lttng_uprobes_event_add_callsite(event, callsite);
2454 default:
2455 return -EINVAL;
2456 }
2457 }
2458
2459 static
2460 void lttng_enabler_destroy(struct lttng_event_enabler_common *enabler)
2461 {
2462 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2463
2464 /* Destroy filter bytecode */
2465 list_for_each_entry_safe(filter_node, tmp_filter_node,
2466 &enabler->filter_bytecode_head, node) {
2467 lttng_kvfree(filter_node);
2468 }
2469 }
2470
2471 void lttng_event_enabler_destroy(struct lttng_event_enabler_common *event_enabler)
2472 {
2473 switch (event_enabler->enabler_type) {
2474 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2475 {
2476 struct lttng_event_recorder_enabler *event_recorder_enabler =
2477 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2478
2479 lttng_enabler_destroy(event_enabler);
2480 if (event_recorder_enabler->published)
2481 list_del(&event_recorder_enabler->node);
2482 kfree(event_recorder_enabler);
2483 break;
2484 }
2485 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2486 {
2487 struct lttng_event_notifier_enabler *event_notifier_enabler =
2488 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2489
2490 lttng_enabler_destroy(event_enabler);
2491 if (event_notifier_enabler->published)
2492 list_del(&event_notifier_enabler->node);
2493 kfree(event_notifier_enabler);
2494 break;
2495 }
2496 default:
2497 WARN_ON_ONCE(1);
2498 }
2499 }
2500
2501 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2502 enum lttng_enabler_format_type format_type,
2503 struct lttng_kernel_abi_event_notifier *event_notifier_param,
2504 struct lttng_event_notifier_group *event_notifier_group)
2505 {
2506 struct lttng_event_notifier_enabler *event_notifier_enabler;
2507
2508 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2509 if (!event_notifier_enabler)
2510 return NULL;
2511
2512 event_notifier_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_NOTIFIER;
2513 event_notifier_enabler->parent.format_type = format_type;
2514 INIT_LIST_HEAD(&event_notifier_enabler->parent.filter_bytecode_head);
2515 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2516
2517 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2518 event_notifier_enabler->num_captures = 0;
2519
2520 memcpy(&event_notifier_enabler->parent.event_param, &event_notifier_param->event,
2521 sizeof(event_notifier_enabler->parent.event_param));
2522
2523 event_notifier_enabler->parent.enabled = 0;
2524 event_notifier_enabler->parent.user_token = event_notifier_param->event.token;
2525 event_notifier_enabler->group = event_notifier_group;
2526 return event_notifier_enabler;
2527 }
2528
2529 void lttng_event_notifier_enabler_group_add(struct lttng_event_notifier_group *event_notifier_group,
2530 struct lttng_event_notifier_enabler *event_notifier_enabler)
2531 {
2532 mutex_lock(&sessions_mutex);
2533 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2534 event_notifier_enabler->published = true;
2535 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2536 mutex_unlock(&sessions_mutex);
2537 }
2538
2539 int lttng_event_notifier_enabler_enable(
2540 struct lttng_event_notifier_enabler *event_notifier_enabler)
2541 {
2542 mutex_lock(&sessions_mutex);
2543 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2544 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2545 mutex_unlock(&sessions_mutex);
2546 return 0;
2547 }
2548
2549 int lttng_event_notifier_enabler_disable(
2550 struct lttng_event_notifier_enabler *event_notifier_enabler)
2551 {
2552 mutex_lock(&sessions_mutex);
2553 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2554 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2555 mutex_unlock(&sessions_mutex);
2556 return 0;
2557 }
2558
2559 int lttng_event_notifier_enabler_attach_capture_bytecode(
2560 struct lttng_event_notifier_enabler *event_notifier_enabler,
2561 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2562 {
2563 struct lttng_kernel_bytecode_node *bytecode_node;
2564 struct lttng_event_enabler_common *enabler =
2565 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2566 uint32_t bytecode_len;
2567 int ret;
2568
2569 ret = get_user(bytecode_len, &bytecode->len);
2570 if (ret)
2571 return ret;
2572
2573 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2574 GFP_KERNEL);
2575 if (!bytecode_node)
2576 return -ENOMEM;
2577
2578 ret = copy_from_user(&bytecode_node->bc, bytecode,
2579 sizeof(*bytecode) + bytecode_len);
2580 if (ret)
2581 goto error_free;
2582
2583 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2584 bytecode_node->enabler = enabler;
2585
2586 /* Enforce length based on allocated size */
2587 bytecode_node->bc.len = bytecode_len;
2588 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2589
2590 event_notifier_enabler->num_captures++;
2591
2592 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2593 goto end;
2594
2595 error_free:
2596 lttng_kvfree(bytecode_node);
2597 end:
2598 return ret;
2599 }
2600
2601 static
2602 void lttng_event_sync_filter_state(struct lttng_kernel_event_common *event)
2603 {
2604 int has_enablers_without_filter_bytecode = 0, nr_filters = 0;
2605 struct lttng_kernel_bytecode_runtime *runtime;
2606 struct lttng_enabler_ref *enabler_ref;
2607
2608 /* Check if has enablers without bytecode enabled */
2609 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2610 if (enabler_ref->ref->enabled
2611 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2612 has_enablers_without_filter_bytecode = 1;
2613 break;
2614 }
2615 }
2616 event->priv->has_enablers_without_filter_bytecode = has_enablers_without_filter_bytecode;
2617
2618 /* Enable filters */
2619 list_for_each_entry(runtime, &event->priv->filter_bytecode_runtime_head, node) {
2620 lttng_bytecode_sync_state(runtime);
2621 nr_filters++;
2622 }
2623 WRITE_ONCE(event->eval_filter, !(has_enablers_without_filter_bytecode || !nr_filters));
2624 }
2625
2626 static
2627 void lttng_event_sync_capture_state(struct lttng_kernel_event_common *event)
2628 {
2629 switch (event->type) {
2630 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2631 break;
2632 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2633 {
2634 struct lttng_kernel_event_notifier *event_notifier =
2635 container_of(event, struct lttng_kernel_event_notifier, parent);
2636 struct lttng_kernel_bytecode_runtime *runtime;
2637 int nr_captures = 0;
2638
2639 /* Enable captures */
2640 list_for_each_entry(runtime, &event_notifier->priv->capture_bytecode_runtime_head, node) {
2641 lttng_bytecode_sync_state(runtime);
2642 nr_captures++;
2643 }
2644 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2645 break;
2646 }
2647 default:
2648 WARN_ON_ONCE(1);
2649 }
2650 }
2651
2652 /*
2653 * lttng_session_sync_event_enablers should be called just before starting a
2654 * session.
2655 * Should be called with sessions mutex held.
2656 */
2657 static
2658 void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2659 {
2660 struct lttng_event_recorder_enabler *event_enabler;
2661 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2662
2663 list_for_each_entry(event_enabler, &session->priv->enablers_head, node)
2664 lttng_event_enabler_ref_events(&event_enabler->parent);
2665 /*
2666 * For each event, if at least one of its enablers is enabled,
2667 * and its channel and session transient states are enabled, we
2668 * enable the event, else we disable it.
2669 */
2670 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
2671 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2672 struct lttng_enabler_ref *enabler_ref;
2673 int enabled = 0;
2674
2675 switch (event_recorder_priv->parent.instrumentation) {
2676 case LTTNG_KERNEL_ABI_TRACEPOINT:
2677 lttng_fallthrough;
2678 case LTTNG_KERNEL_ABI_SYSCALL:
2679 /* Enable events */
2680 list_for_each_entry(enabler_ref,
2681 &event_recorder_priv->parent.enablers_ref_head, node) {
2682 if (enabler_ref->ref->enabled) {
2683 enabled = 1;
2684 break;
2685 }
2686 }
2687 break;
2688
2689 default:
2690 /* Not handled with lazy sync. */
2691 continue;
2692 }
2693 /*
2694 * Enabled state is based on union of enablers, with
2695 * intesection of session and channel transient enable
2696 * states.
2697 */
2698 enabled = enabled && session->priv->tstate && event_recorder->chan->priv->parent.tstate;
2699
2700 WRITE_ONCE(event_recorder->parent.enabled, enabled);
2701 /*
2702 * Sync tracepoint registration with event enabled
2703 * state.
2704 */
2705 if (enabled) {
2706 register_event(&event_recorder->parent);
2707 } else {
2708 _lttng_event_unregister(&event_recorder->parent);
2709 }
2710
2711 lttng_event_sync_filter_state(&event_recorder_priv->pub->parent);
2712 }
2713 }
2714
2715 /*
2716 * Apply enablers to session events, adding events to session if need
2717 * be. It is required after each modification applied to an active
2718 * session, and right before session "start".
2719 * "lazy" sync means we only sync if required.
2720 * Should be called with sessions mutex held.
2721 */
2722 static
2723 void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2724 {
2725 /* We can skip if session is not active */
2726 if (!session->active)
2727 return;
2728 lttng_session_sync_event_enablers(session);
2729 }
2730
2731 static
2732 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2733 {
2734 struct lttng_event_notifier_enabler *event_notifier_enabler;
2735 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2736
2737 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2738 lttng_event_enabler_ref_events(&event_notifier_enabler->parent);
2739
2740 /*
2741 * For each event_notifier, if at least one of its enablers is enabled,
2742 * we enable the event_notifier, else we disable it.
2743 */
2744 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, parent.node) {
2745 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2746 struct lttng_enabler_ref *enabler_ref;
2747 int enabled = 0;
2748
2749 switch (event_notifier_priv->parent.instrumentation) {
2750 case LTTNG_KERNEL_ABI_TRACEPOINT:
2751 lttng_fallthrough;
2752 case LTTNG_KERNEL_ABI_SYSCALL:
2753 /* Enable event_notifiers */
2754 list_for_each_entry(enabler_ref,
2755 &event_notifier_priv->parent.enablers_ref_head, node) {
2756 if (enabler_ref->ref->enabled) {
2757 enabled = 1;
2758 break;
2759 }
2760 }
2761 break;
2762
2763 default:
2764 /* Not handled with sync. */
2765 continue;
2766 }
2767
2768 WRITE_ONCE(event_notifier->parent.enabled, enabled);
2769 /*
2770 * Sync tracepoint registration with event_notifier enabled
2771 * state.
2772 */
2773 if (enabled) {
2774 if (!event_notifier_priv->parent.registered)
2775 register_event(&event_notifier->parent);
2776 } else {
2777 if (event_notifier_priv->parent.registered)
2778 _lttng_event_unregister(&event_notifier->parent);
2779 }
2780
2781 lttng_event_sync_filter_state(&event_notifier_priv->pub->parent);
2782 lttng_event_sync_capture_state(&event_notifier_priv->pub->parent);
2783 }
2784 }
2785
2786 static
2787 void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler)
2788 {
2789 switch (event_enabler->enabler_type) {
2790 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2791 {
2792 struct lttng_event_recorder_enabler *event_recorder_enabler =
2793 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2794 lttng_session_lazy_sync_event_enablers(event_recorder_enabler->chan->parent.session);
2795 break;
2796 }
2797 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2798 {
2799 struct lttng_event_notifier_enabler *event_notifier_enabler =
2800 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2801 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2802 break;
2803 }
2804 default:
2805 WARN_ON_ONCE(1);
2806 }
2807 }
2808
2809 /*
2810 * Serialize at most one packet worth of metadata into a metadata
2811 * channel.
2812 * We grab the metadata cache mutex to get exclusive access to our metadata
2813 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2814 * allows us to do racy operations such as looking for remaining space left in
2815 * packet and write, since mutual exclusion protects us from concurrent writes.
2816 * Mutual exclusion on the metadata cache allow us to read the cache content
2817 * without racing against reallocation of the cache by updates.
2818 * Returns the number of bytes written in the channel, 0 if no data
2819 * was written and a negative value on error.
2820 */
2821 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2822 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2823 {
2824 struct lttng_kernel_ring_buffer_ctx ctx;
2825 int ret = 0;
2826 size_t len, reserve_len;
2827
2828 /*
2829 * Ensure we support mutiple get_next / put sequences followed by
2830 * put_next. The metadata cache lock protects reading the metadata
2831 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2832 * "flush" operations on the buffer invoked by different processes.
2833 * Moreover, since the metadata cache memory can be reallocated, we
2834 * need to have exclusive access against updates even though we only
2835 * read it.
2836 */
2837 mutex_lock(&stream->metadata_cache->lock);
2838 WARN_ON(stream->metadata_in < stream->metadata_out);
2839 if (stream->metadata_in != stream->metadata_out)
2840 goto end;
2841
2842 /* Metadata regenerated, change the version. */
2843 if (stream->metadata_cache->version != stream->version)
2844 stream->version = stream->metadata_cache->version;
2845
2846 len = stream->metadata_cache->metadata_written -
2847 stream->metadata_in;
2848 if (!len)
2849 goto end;
2850 reserve_len = min_t(size_t,
2851 stream->transport->ops.priv->packet_avail_size(chan),
2852 len);
2853 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2854 sizeof(char), NULL);
2855 /*
2856 * If reservation failed, return an error to the caller.
2857 */
2858 ret = stream->transport->ops.event_reserve(&ctx);
2859 if (ret != 0) {
2860 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2861 stream->coherent = false;
2862 goto end;
2863 }
2864 stream->transport->ops.event_write(&ctx,
2865 stream->metadata_cache->data + stream->metadata_in,
2866 reserve_len, 1);
2867 stream->transport->ops.event_commit(&ctx);
2868 stream->metadata_in += reserve_len;
2869 if (reserve_len < len)
2870 stream->coherent = false;
2871 else
2872 stream->coherent = true;
2873 ret = reserve_len;
2874
2875 end:
2876 if (coherent)
2877 *coherent = stream->coherent;
2878 mutex_unlock(&stream->metadata_cache->lock);
2879 return ret;
2880 }
2881
2882 static
2883 void lttng_metadata_begin(struct lttng_kernel_session *session)
2884 {
2885 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
2886 mutex_lock(&session->priv->metadata_cache->lock);
2887 }
2888
2889 static
2890 void lttng_metadata_end(struct lttng_kernel_session *session)
2891 {
2892 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2893 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
2894 struct lttng_metadata_stream *stream;
2895
2896 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
2897 wake_up_interruptible(&stream->read_wait);
2898 mutex_unlock(&session->priv->metadata_cache->lock);
2899 }
2900 }
2901
2902 /*
2903 * Write the metadata to the metadata cache.
2904 * Must be called with sessions_mutex held.
2905 * The metadata cache lock protects us from concurrent read access from
2906 * thread outputting metadata content to ring buffer.
2907 * The content of the printf is printed as a single atomic metadata
2908 * transaction.
2909 */
2910 int lttng_metadata_printf(struct lttng_kernel_session *session,
2911 const char *fmt, ...)
2912 {
2913 char *str;
2914 size_t len;
2915 va_list ap;
2916
2917 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2918
2919 va_start(ap, fmt);
2920 str = kvasprintf(GFP_KERNEL, fmt, ap);
2921 va_end(ap);
2922 if (!str)
2923 return -ENOMEM;
2924
2925 len = strlen(str);
2926 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2927 if (session->priv->metadata_cache->metadata_written + len >
2928 session->priv->metadata_cache->cache_alloc) {
2929 char *tmp_cache_realloc;
2930 unsigned int tmp_cache_alloc_size;
2931
2932 tmp_cache_alloc_size = max_t(unsigned int,
2933 session->priv->metadata_cache->cache_alloc + len,
2934 session->priv->metadata_cache->cache_alloc << 1);
2935 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2936 if (!tmp_cache_realloc)
2937 goto err;
2938 if (session->priv->metadata_cache->data) {
2939 memcpy(tmp_cache_realloc,
2940 session->priv->metadata_cache->data,
2941 session->priv->metadata_cache->cache_alloc);
2942 vfree(session->priv->metadata_cache->data);
2943 }
2944
2945 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2946 session->priv->metadata_cache->data = tmp_cache_realloc;
2947 }
2948 memcpy(session->priv->metadata_cache->data +
2949 session->priv->metadata_cache->metadata_written,
2950 str, len);
2951 session->priv->metadata_cache->metadata_written += len;
2952 kfree(str);
2953
2954 return 0;
2955
2956 err:
2957 kfree(str);
2958 return -ENOMEM;
2959 }
2960
2961 static
2962 int print_tabs(struct lttng_kernel_session *session, size_t nesting)
2963 {
2964 size_t i;
2965
2966 for (i = 0; i < nesting; i++) {
2967 int ret;
2968
2969 ret = lttng_metadata_printf(session, " ");
2970 if (ret) {
2971 return ret;
2972 }
2973 }
2974 return 0;
2975 }
2976
2977 static
2978 int lttng_field_name_statedump(struct lttng_kernel_session *session,
2979 const struct lttng_kernel_event_field *field,
2980 size_t nesting)
2981 {
2982 return lttng_metadata_printf(session, " _%s;\n", field->name);
2983 }
2984
2985 static
2986 int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
2987 const struct lttng_kernel_type_integer *type,
2988 enum lttng_kernel_string_encoding parent_encoding,
2989 size_t nesting)
2990 {
2991 int ret;
2992
2993 ret = print_tabs(session, nesting);
2994 if (ret)
2995 return ret;
2996 ret = lttng_metadata_printf(session,
2997 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
2998 type->size,
2999 type->alignment,
3000 type->signedness,
3001 (parent_encoding == lttng_kernel_string_encoding_none)
3002 ? "none"
3003 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
3004 ? "UTF8"
3005 : "ASCII",
3006 type->base,
3007 #if __BYTE_ORDER == __BIG_ENDIAN
3008 type->reverse_byte_order ? " byte_order = le;" : ""
3009 #else
3010 type->reverse_byte_order ? " byte_order = be;" : ""
3011 #endif
3012 );
3013 return ret;
3014 }
3015
3016 /*
3017 * Must be called with sessions_mutex held.
3018 */
3019 static
3020 int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
3021 const struct lttng_kernel_type_struct *type,
3022 size_t nesting)
3023 {
3024 const char *prev_field_name = NULL;
3025 int ret;
3026 uint32_t i, nr_fields;
3027 unsigned int alignment;
3028
3029 ret = print_tabs(session, nesting);
3030 if (ret)
3031 return ret;
3032 ret = lttng_metadata_printf(session,
3033 "struct {\n");
3034 if (ret)
3035 return ret;
3036 nr_fields = type->nr_fields;
3037 for (i = 0; i < nr_fields; i++) {
3038 const struct lttng_kernel_event_field *iter_field;
3039
3040 iter_field = type->fields[i];
3041 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
3042 if (ret)
3043 return ret;
3044 }
3045 ret = print_tabs(session, nesting);
3046 if (ret)
3047 return ret;
3048 alignment = type->alignment;
3049 if (alignment) {
3050 ret = lttng_metadata_printf(session,
3051 "} align(%u)",
3052 alignment);
3053 } else {
3054 ret = lttng_metadata_printf(session,
3055 "}");
3056 }
3057 return ret;
3058 }
3059
3060 /*
3061 * Must be called with sessions_mutex held.
3062 */
3063 static
3064 int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
3065 const struct lttng_kernel_event_field *field,
3066 size_t nesting)
3067 {
3068 int ret;
3069
3070 ret = _lttng_struct_type_statedump(session,
3071 lttng_kernel_get_type_struct(field->type), nesting);
3072 if (ret)
3073 return ret;
3074 return lttng_field_name_statedump(session, field, nesting);
3075 }
3076
3077 /*
3078 * Must be called with sessions_mutex held.
3079 */
3080 static
3081 int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
3082 const struct lttng_kernel_type_variant *type,
3083 size_t nesting,
3084 const char *prev_field_name)
3085 {
3086 const char *tag_name;
3087 int ret;
3088 uint32_t i, nr_choices;
3089
3090 tag_name = type->tag_name;
3091 if (!tag_name)
3092 tag_name = prev_field_name;
3093 if (!tag_name)
3094 return -EINVAL;
3095 /*
3096 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3097 */
3098 if (type->alignment != 0)
3099 return -EINVAL;
3100 ret = print_tabs(session, nesting);
3101 if (ret)
3102 return ret;
3103 ret = lttng_metadata_printf(session,
3104 "variant <_%s> {\n",
3105 tag_name);
3106 if (ret)
3107 return ret;
3108 nr_choices = type->nr_choices;
3109 for (i = 0; i < nr_choices; i++) {
3110 const struct lttng_kernel_event_field *iter_field;
3111
3112 iter_field = type->choices[i];
3113 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3114 if (ret)
3115 return ret;
3116 }
3117 ret = print_tabs(session, nesting);
3118 if (ret)
3119 return ret;
3120 ret = lttng_metadata_printf(session,
3121 "}");
3122 return ret;
3123 }
3124
3125 /*
3126 * Must be called with sessions_mutex held.
3127 */
3128 static
3129 int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3130 const struct lttng_kernel_event_field *field,
3131 size_t nesting,
3132 const char *prev_field_name)
3133 {
3134 int ret;
3135
3136 ret = _lttng_variant_type_statedump(session,
3137 lttng_kernel_get_type_variant(field->type), nesting,
3138 prev_field_name);
3139 if (ret)
3140 return ret;
3141 return lttng_field_name_statedump(session, field, nesting);
3142 }
3143
3144 /*
3145 * Must be called with sessions_mutex held.
3146 */
3147 static
3148 int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3149 const struct lttng_kernel_event_field *field,
3150 size_t nesting)
3151 {
3152 int ret;
3153 const struct lttng_kernel_type_array *array_type;
3154 const struct lttng_kernel_type_common *elem_type;
3155
3156 array_type = lttng_kernel_get_type_array(field->type);
3157 WARN_ON_ONCE(!array_type);
3158
3159 if (array_type->alignment) {
3160 ret = print_tabs(session, nesting);
3161 if (ret)
3162 return ret;
3163 ret = lttng_metadata_printf(session,
3164 "struct { } align(%u) _%s_padding;\n",
3165 array_type->alignment * CHAR_BIT,
3166 field->name);
3167 if (ret)
3168 return ret;
3169 }
3170 /*
3171 * Nested compound types: Only array of structures and variants are
3172 * currently supported.
3173 */
3174 elem_type = array_type->elem_type;
3175 switch (elem_type->type) {
3176 case lttng_kernel_type_integer:
3177 case lttng_kernel_type_struct:
3178 case lttng_kernel_type_variant:
3179 ret = _lttng_type_statedump(session, elem_type,
3180 array_type->encoding, nesting);
3181 if (ret)
3182 return ret;
3183 break;
3184
3185 default:
3186 return -EINVAL;
3187 }
3188 ret = lttng_metadata_printf(session,
3189 " _%s[%u];\n",
3190 field->name,
3191 array_type->length);
3192 return ret;
3193 }
3194
3195 /*
3196 * Must be called with sessions_mutex held.
3197 */
3198 static
3199 int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3200 const struct lttng_kernel_event_field *field,
3201 size_t nesting,
3202 const char *prev_field_name)
3203 {
3204 int ret;
3205 const char *length_name;
3206 const struct lttng_kernel_type_sequence *sequence_type;
3207 const struct lttng_kernel_type_common *elem_type;
3208
3209 sequence_type = lttng_kernel_get_type_sequence(field->type);
3210 WARN_ON_ONCE(!sequence_type);
3211
3212 length_name = sequence_type->length_name;
3213 if (!length_name)
3214 length_name = prev_field_name;
3215 if (!length_name)
3216 return -EINVAL;
3217
3218 if (sequence_type->alignment) {
3219 ret = print_tabs(session, nesting);
3220 if (ret)
3221 return ret;
3222 ret = lttng_metadata_printf(session,
3223 "struct { } align(%u) _%s_padding;\n",
3224 sequence_type->alignment * CHAR_BIT,
3225 field->name);
3226 if (ret)
3227 return ret;
3228 }
3229
3230 /*
3231 * Nested compound types: Only array of structures and variants are
3232 * currently supported.
3233 */
3234 elem_type = sequence_type->elem_type;
3235 switch (elem_type->type) {
3236 case lttng_kernel_type_integer:
3237 case lttng_kernel_type_struct:
3238 case lttng_kernel_type_variant:
3239 ret = _lttng_type_statedump(session, elem_type,
3240 sequence_type->encoding, nesting);
3241 if (ret)
3242 return ret;
3243 break;
3244
3245 default:
3246 return -EINVAL;
3247 }
3248 ret = lttng_metadata_printf(session,
3249 " _%s[ _%s ];\n",
3250 field->name,
3251 length_name);
3252 return ret;
3253 }
3254
3255 /*
3256 * Must be called with sessions_mutex held.
3257 */
3258 static
3259 int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3260 const struct lttng_kernel_type_enum *type,
3261 size_t nesting)
3262 {
3263 const struct lttng_kernel_enum_desc *enum_desc;
3264 const struct lttng_kernel_type_common *container_type;
3265 int ret;
3266 unsigned int i, nr_entries;
3267
3268 container_type = type->container_type;
3269 if (container_type->type != lttng_kernel_type_integer) {
3270 ret = -EINVAL;
3271 goto end;
3272 }
3273 enum_desc = type->desc;
3274 nr_entries = enum_desc->nr_entries;
3275
3276 ret = print_tabs(session, nesting);
3277 if (ret)
3278 goto end;
3279 ret = lttng_metadata_printf(session, "enum : ");
3280 if (ret)
3281 goto end;
3282 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3283 lttng_kernel_string_encoding_none, 0);
3284 if (ret)
3285 goto end;
3286 ret = lttng_metadata_printf(session, " {\n");
3287 if (ret)
3288 goto end;
3289 /* Dump all entries */
3290 for (i = 0; i < nr_entries; i++) {
3291 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3292 int j, len;
3293
3294 ret = print_tabs(session, nesting + 1);
3295 if (ret)
3296 goto end;
3297 ret = lttng_metadata_printf(session,
3298 "\"");
3299 if (ret)
3300 goto end;
3301 len = strlen(entry->string);
3302 /* Escape the character '"' */
3303 for (j = 0; j < len; j++) {
3304 char c = entry->string[j];
3305
3306 switch (c) {
3307 case '"':
3308 ret = lttng_metadata_printf(session,
3309 "\\\"");
3310 break;
3311 case '\\':
3312 ret = lttng_metadata_printf(session,
3313 "\\\\");
3314 break;
3315 default:
3316 ret = lttng_metadata_printf(session,
3317 "%c", c);
3318 break;
3319 }
3320 if (ret)
3321 goto end;
3322 }
3323 ret = lttng_metadata_printf(session, "\"");
3324 if (ret)
3325 goto end;
3326
3327 if (entry->options.is_auto) {
3328 ret = lttng_metadata_printf(session, ",\n");
3329 if (ret)
3330 goto end;
3331 } else {
3332 ret = lttng_metadata_printf(session,
3333 " = ");
3334 if (ret)
3335 goto end;
3336 if (entry->start.signedness)
3337 ret = lttng_metadata_printf(session,
3338 "%lld", (long long) entry->start.value);
3339 else
3340 ret = lttng_metadata_printf(session,
3341 "%llu", entry->start.value);
3342 if (ret)
3343 goto end;
3344 if (entry->start.signedness == entry->end.signedness &&
3345 entry->start.value
3346 == entry->end.value) {
3347 ret = lttng_metadata_printf(session,
3348 ",\n");
3349 } else {
3350 if (entry->end.signedness) {
3351 ret = lttng_metadata_printf(session,
3352 " ... %lld,\n",
3353 (long long) entry->end.value);
3354 } else {
3355 ret = lttng_metadata_printf(session,
3356 " ... %llu,\n",
3357 entry->end.value);
3358 }
3359 }
3360 if (ret)
3361 goto end;
3362 }
3363 }
3364 ret = print_tabs(session, nesting);
3365 if (ret)
3366 goto end;
3367 ret = lttng_metadata_printf(session, "}");
3368 end:
3369 return ret;
3370 }
3371
3372 /*
3373 * Must be called with sessions_mutex held.
3374 */
3375 static
3376 int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3377 const struct lttng_kernel_event_field *field,
3378 size_t nesting)
3379 {
3380 int ret;
3381 const struct lttng_kernel_type_enum *enum_type;
3382
3383 enum_type = lttng_kernel_get_type_enum(field->type);
3384 WARN_ON_ONCE(!enum_type);
3385 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3386 if (ret)
3387 return ret;
3388 return lttng_field_name_statedump(session, field, nesting);
3389 }
3390
3391 static
3392 int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3393 const struct lttng_kernel_event_field *field,
3394 size_t nesting)
3395 {
3396 int ret;
3397
3398 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3399 lttng_kernel_string_encoding_none, nesting);
3400 if (ret)
3401 return ret;
3402 return lttng_field_name_statedump(session, field, nesting);
3403 }
3404
3405 static
3406 int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3407 const struct lttng_kernel_type_string *type,
3408 size_t nesting)
3409 {
3410 int ret;
3411
3412 /* Default encoding is UTF8 */
3413 ret = print_tabs(session, nesting);
3414 if (ret)
3415 return ret;
3416 ret = lttng_metadata_printf(session,
3417 "string%s",
3418 type->encoding == lttng_kernel_string_encoding_ASCII ?
3419 " { encoding = ASCII; }" : "");
3420 return ret;
3421 }
3422
3423 static
3424 int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3425 const struct lttng_kernel_event_field *field,
3426 size_t nesting)
3427 {
3428 const struct lttng_kernel_type_string *string_type;
3429 int ret;
3430
3431 string_type = lttng_kernel_get_type_string(field->type);
3432 WARN_ON_ONCE(!string_type);
3433 ret = _lttng_string_type_statedump(session, string_type, nesting);
3434 if (ret)
3435 return ret;
3436 return lttng_field_name_statedump(session, field, nesting);
3437 }
3438
3439 /*
3440 * Must be called with sessions_mutex held.
3441 */
3442 static
3443 int _lttng_type_statedump(struct lttng_kernel_session *session,
3444 const struct lttng_kernel_type_common *type,
3445 enum lttng_kernel_string_encoding parent_encoding,
3446 size_t nesting)
3447 {
3448 int ret = 0;
3449
3450 switch (type->type) {
3451 case lttng_kernel_type_integer:
3452 ret = _lttng_integer_type_statedump(session,
3453 lttng_kernel_get_type_integer(type),
3454 parent_encoding, nesting);
3455 break;
3456 case lttng_kernel_type_enum:
3457 ret = _lttng_enum_type_statedump(session,
3458 lttng_kernel_get_type_enum(type),
3459 nesting);
3460 break;
3461 case lttng_kernel_type_string:
3462 ret = _lttng_string_type_statedump(session,
3463 lttng_kernel_get_type_string(type),
3464 nesting);
3465 break;
3466 case lttng_kernel_type_struct:
3467 ret = _lttng_struct_type_statedump(session,
3468 lttng_kernel_get_type_struct(type),
3469 nesting);
3470 break;
3471 case lttng_kernel_type_variant:
3472 ret = _lttng_variant_type_statedump(session,
3473 lttng_kernel_get_type_variant(type),
3474 nesting, NULL);
3475 break;
3476
3477 /* Nested arrays and sequences are not supported yet. */
3478 case lttng_kernel_type_array:
3479 case lttng_kernel_type_sequence:
3480 default:
3481 WARN_ON_ONCE(1);
3482 return -EINVAL;
3483 }
3484 return ret;
3485 }
3486
3487 /*
3488 * Must be called with sessions_mutex held.
3489 */
3490 static
3491 int _lttng_field_statedump(struct lttng_kernel_session *session,
3492 const struct lttng_kernel_event_field *field,
3493 size_t nesting,
3494 const char **prev_field_name_p)
3495 {
3496 const char *prev_field_name = NULL;
3497 int ret = 0;
3498
3499 if (prev_field_name_p)
3500 prev_field_name = *prev_field_name_p;
3501 switch (field->type->type) {
3502 case lttng_kernel_type_integer:
3503 ret = _lttng_integer_field_statedump(session, field, nesting);
3504 break;
3505 case lttng_kernel_type_enum:
3506 ret = _lttng_enum_field_statedump(session, field, nesting);
3507 break;
3508 case lttng_kernel_type_string:
3509 ret = _lttng_string_field_statedump(session, field, nesting);
3510 break;
3511 case lttng_kernel_type_struct:
3512 ret = _lttng_struct_field_statedump(session, field, nesting);
3513 break;
3514 case lttng_kernel_type_array:
3515 ret = _lttng_array_field_statedump(session, field, nesting);
3516 break;
3517 case lttng_kernel_type_sequence:
3518 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3519 break;
3520 case lttng_kernel_type_variant:
3521 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3522 break;
3523
3524 default:
3525 WARN_ON_ONCE(1);
3526 return -EINVAL;
3527 }
3528 if (prev_field_name_p)
3529 *prev_field_name_p = field->name;
3530 return ret;
3531 }
3532
3533 static
3534 int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3535 struct lttng_kernel_ctx *ctx)
3536 {
3537 const char *prev_field_name = NULL;
3538 int ret = 0;
3539 int i;
3540
3541 if (!ctx)
3542 return 0;
3543 for (i = 0; i < ctx->nr_fields; i++) {
3544 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3545
3546 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3547 if (ret)
3548 return ret;
3549 }
3550 return ret;
3551 }
3552
3553 static
3554 int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3555 struct lttng_kernel_event_recorder *event_recorder)
3556 {
3557 const char *prev_field_name = NULL;
3558 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3559 int ret = 0;
3560 int i;
3561
3562 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3563 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3564
3565 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3566 if (ret)
3567 return ret;
3568 }
3569 return ret;
3570 }
3571
3572 /*
3573 * Must be called with sessions_mutex held.
3574 * The entire event metadata is printed as a single atomic metadata
3575 * transaction.
3576 */
3577 static
3578 int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
3579 struct lttng_kernel_channel_buffer *chan,
3580 struct lttng_kernel_event_recorder *event_recorder)
3581 {
3582 int ret = 0;
3583
3584 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3585 return 0;
3586 if (chan->priv->channel_type == METADATA_CHANNEL)
3587 return 0;
3588
3589 lttng_metadata_begin(session);
3590
3591 ret = lttng_metadata_printf(session,
3592 "event {\n"
3593 " name = \"%s\";\n"
3594 " id = %u;\n"
3595 " stream_id = %u;\n",
3596 event_recorder->priv->parent.desc->event_name,
3597 event_recorder->priv->id,
3598 event_recorder->chan->priv->id);
3599 if (ret)
3600 goto end;
3601
3602 ret = lttng_metadata_printf(session,
3603 " fields := struct {\n"
3604 );
3605 if (ret)
3606 goto end;
3607
3608 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3609 if (ret)
3610 goto end;
3611
3612 /*
3613 * LTTng space reservation can only reserve multiples of the
3614 * byte size.
3615 */
3616 ret = lttng_metadata_printf(session,
3617 " };\n"
3618 "};\n\n");
3619 if (ret)
3620 goto end;
3621
3622 event_recorder->priv->metadata_dumped = 1;
3623 end:
3624 lttng_metadata_end(session);
3625 return ret;
3626
3627 }
3628
3629 /*
3630 * Must be called with sessions_mutex held.
3631 * The entire channel metadata is printed as a single atomic metadata
3632 * transaction.
3633 */
3634 static
3635 int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3636 struct lttng_kernel_channel_buffer *chan)
3637 {
3638 int ret = 0;
3639
3640 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3641 return 0;
3642
3643 if (chan->priv->channel_type == METADATA_CHANNEL)
3644 return 0;
3645
3646 lttng_metadata_begin(session);
3647
3648 WARN_ON_ONCE(!chan->priv->header_type);
3649 ret = lttng_metadata_printf(session,
3650 "stream {\n"
3651 " id = %u;\n"
3652 " event.header := %s;\n"
3653 " packet.context := struct packet_context;\n",
3654 chan->priv->id,
3655 chan->priv->header_type == 1 ? "struct event_header_compact" :
3656 "struct event_header_large");
3657 if (ret)
3658 goto end;
3659
3660 if (chan->priv->ctx) {
3661 ret = lttng_metadata_printf(session,
3662 " event.context := struct {\n");
3663 if (ret)
3664 goto end;
3665 }
3666 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3667 if (ret)
3668 goto end;
3669 if (chan->priv->ctx) {
3670 ret = lttng_metadata_printf(session,
3671 " };\n");
3672 if (ret)
3673 goto end;
3674 }
3675
3676 ret = lttng_metadata_printf(session,
3677 "};\n\n");
3678
3679 chan->priv->metadata_dumped = 1;
3680 end:
3681 lttng_metadata_end(session);
3682 return ret;
3683 }
3684
3685 /*
3686 * Must be called with sessions_mutex held.
3687 */
3688 static
3689 int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3690 {
3691 return lttng_metadata_printf(session,
3692 "struct packet_context {\n"
3693 " uint64_clock_monotonic_t timestamp_begin;\n"
3694 " uint64_clock_monotonic_t timestamp_end;\n"
3695 " uint64_t content_size;\n"
3696 " uint64_t packet_size;\n"
3697 " uint64_t packet_seq_num;\n"
3698 " unsigned long events_discarded;\n"
3699 " uint32_t cpu_id;\n"
3700 "};\n\n"
3701 );
3702 }
3703
3704 /*
3705 * Compact header:
3706 * id: range: 0 - 30.
3707 * id 31 is reserved to indicate an extended header.
3708 *
3709 * Large header:
3710 * id: range: 0 - 65534.
3711 * id 65535 is reserved to indicate an extended header.
3712 *
3713 * Must be called with sessions_mutex held.
3714 */
3715 static
3716 int _lttng_event_header_declare(struct lttng_kernel_session *session)
3717 {
3718 return lttng_metadata_printf(session,
3719 "struct event_header_compact {\n"
3720 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3721 " variant <id> {\n"
3722 " struct {\n"
3723 " uint27_clock_monotonic_t timestamp;\n"
3724 " } compact;\n"
3725 " struct {\n"
3726 " uint32_t id;\n"
3727 " uint64_clock_monotonic_t timestamp;\n"
3728 " } extended;\n"
3729 " } v;\n"
3730 "} align(%u);\n"
3731 "\n"
3732 "struct event_header_large {\n"
3733 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3734 " variant <id> {\n"
3735 " struct {\n"
3736 " uint32_clock_monotonic_t timestamp;\n"
3737 " } compact;\n"
3738 " struct {\n"
3739 " uint32_t id;\n"
3740 " uint64_clock_monotonic_t timestamp;\n"
3741 " } extended;\n"
3742 " } v;\n"
3743 "} align(%u);\n\n",
3744 lttng_alignof(uint32_t) * CHAR_BIT,
3745 lttng_alignof(uint16_t) * CHAR_BIT
3746 );
3747 }
3748
3749 /*
3750 * Approximation of NTP time of day to clock monotonic correlation,
3751 * taken at start of trace.
3752 * Yes, this is only an approximation. Yes, we can (and will) do better
3753 * in future versions.
3754 * This function may return a negative offset. It may happen if the
3755 * system sets the REALTIME clock to 0 after boot.
3756 *
3757 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3758 * y2038 compliant.
3759 */
3760 static
3761 int64_t measure_clock_offset(void)
3762 {
3763 uint64_t monotonic_avg, monotonic[2], realtime;
3764 uint64_t tcf = trace_clock_freq();
3765 int64_t offset;
3766 unsigned long flags;
3767 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3768 struct timespec64 rts = { 0, 0 };
3769 #else
3770 struct timespec rts = { 0, 0 };
3771 #endif
3772
3773 /* Disable interrupts to increase correlation precision. */
3774 local_irq_save(flags);
3775 monotonic[0] = trace_clock_read64();
3776 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3777 ktime_get_real_ts64(&rts);
3778 #else
3779 getnstimeofday(&rts);
3780 #endif
3781 monotonic[1] = trace_clock_read64();
3782 local_irq_restore(flags);
3783
3784 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3785 realtime = (uint64_t) rts.tv_sec * tcf;
3786 if (tcf == NSEC_PER_SEC) {
3787 realtime += rts.tv_nsec;
3788 } else {
3789 uint64_t n = rts.tv_nsec * tcf;
3790
3791 do_div(n, NSEC_PER_SEC);
3792 realtime += n;
3793 }
3794 offset = (int64_t) realtime - monotonic_avg;
3795 return offset;
3796 }
3797
3798 static
3799 int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3800 {
3801 int ret = 0;
3802 size_t i;
3803 char cur;
3804
3805 i = 0;
3806 cur = string[i];
3807 while (cur != '\0') {
3808 switch (cur) {
3809 case '\n':
3810 ret = lttng_metadata_printf(session, "%s", "\\n");
3811 break;
3812 case '\\':
3813 case '"':
3814 ret = lttng_metadata_printf(session, "%c", '\\');
3815 if (ret)
3816 goto error;
3817 /* We still print the current char */
3818 lttng_fallthrough;
3819 default:
3820 ret = lttng_metadata_printf(session, "%c", cur);
3821 break;
3822 }
3823
3824 if (ret)
3825 goto error;
3826
3827 cur = string[++i];
3828 }
3829 error:
3830 return ret;
3831 }
3832
3833 static
3834 int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3835 const char *field_value)
3836 {
3837 int ret;
3838
3839 ret = lttng_metadata_printf(session, " %s = \"", field);
3840 if (ret)
3841 goto error;
3842
3843 ret = print_escaped_ctf_string(session, field_value);
3844 if (ret)
3845 goto error;
3846
3847 ret = lttng_metadata_printf(session, "\";\n");
3848
3849 error:
3850 return ret;
3851 }
3852
3853 /*
3854 * Output metadata into this session's metadata buffers.
3855 * Must be called with sessions_mutex held.
3856 */
3857 static
3858 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3859 {
3860 unsigned char *uuid_c = session->priv->uuid.b;
3861 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3862 const char *product_uuid;
3863 struct lttng_kernel_channel_buffer_private *chan_priv;
3864 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3865 int ret = 0;
3866
3867 if (!LTTNG_READ_ONCE(session->active))
3868 return 0;
3869
3870 lttng_metadata_begin(session);
3871
3872 if (session->priv->metadata_dumped)
3873 goto skip_session;
3874
3875 snprintf(uuid_s, sizeof(uuid_s),
3876 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3877 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3878 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3879 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3880 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3881
3882 ret = lttng_metadata_printf(session,
3883 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3884 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3885 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3886 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3887 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3888 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3889 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3890 "\n"
3891 "trace {\n"
3892 " major = %u;\n"
3893 " minor = %u;\n"
3894 " uuid = \"%s\";\n"
3895 " byte_order = %s;\n"
3896 " packet.header := struct {\n"
3897 " uint32_t magic;\n"
3898 " uint8_t uuid[16];\n"
3899 " uint32_t stream_id;\n"
3900 " uint64_t stream_instance_id;\n"
3901 " };\n"
3902 "};\n\n",
3903 lttng_alignof(uint8_t) * CHAR_BIT,
3904 lttng_alignof(uint16_t) * CHAR_BIT,
3905 lttng_alignof(uint32_t) * CHAR_BIT,
3906 lttng_alignof(uint64_t) * CHAR_BIT,
3907 sizeof(unsigned long) * CHAR_BIT,
3908 lttng_alignof(unsigned long) * CHAR_BIT,
3909 CTF_SPEC_MAJOR,
3910 CTF_SPEC_MINOR,
3911 uuid_s,
3912 #if __BYTE_ORDER == __BIG_ENDIAN
3913 "be"
3914 #else
3915 "le"
3916 #endif
3917 );
3918 if (ret)
3919 goto end;
3920
3921 ret = lttng_metadata_printf(session,
3922 "env {\n"
3923 " hostname = \"%s\";\n"
3924 " domain = \"kernel\";\n"
3925 " sysname = \"%s\";\n"
3926 " kernel_release = \"%s\";\n"
3927 " kernel_version = \"%s\";\n"
3928 " tracer_name = \"lttng-modules\";\n"
3929 " tracer_major = %d;\n"
3930 " tracer_minor = %d;\n"
3931 " tracer_patchlevel = %d;\n"
3932 " trace_buffering_scheme = \"global\";\n",
3933 current->nsproxy->uts_ns->name.nodename,
3934 utsname()->sysname,
3935 utsname()->release,
3936 utsname()->version,
3937 LTTNG_MODULES_MAJOR_VERSION,
3938 LTTNG_MODULES_MINOR_VERSION,
3939 LTTNG_MODULES_PATCHLEVEL_VERSION
3940 );
3941 if (ret)
3942 goto end;
3943
3944 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
3945 if (ret)
3946 goto end;
3947 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3948 session->priv->creation_time);
3949 if (ret)
3950 goto end;
3951
3952 /* Add the product UUID to the 'env' section */
3953 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
3954 if (product_uuid) {
3955 ret = lttng_metadata_printf(session,
3956 " product_uuid = \"%s\";\n",
3957 product_uuid
3958 );
3959 if (ret)
3960 goto end;
3961 }
3962
3963 /* Close the 'env' section */
3964 ret = lttng_metadata_printf(session, "};\n\n");
3965 if (ret)
3966 goto end;
3967
3968 ret = lttng_metadata_printf(session,
3969 "clock {\n"
3970 " name = \"%s\";\n",
3971 trace_clock_name()
3972 );
3973 if (ret)
3974 goto end;
3975
3976 if (!trace_clock_uuid(clock_uuid_s)) {
3977 ret = lttng_metadata_printf(session,
3978 " uuid = \"%s\";\n",
3979 clock_uuid_s
3980 );
3981 if (ret)
3982 goto end;
3983 }
3984
3985 ret = lttng_metadata_printf(session,
3986 " description = \"%s\";\n"
3987 " freq = %llu; /* Frequency, in Hz */\n"
3988 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
3989 " offset = %lld;\n"
3990 "};\n\n",
3991 trace_clock_description(),
3992 (unsigned long long) trace_clock_freq(),
3993 (long long) measure_clock_offset()
3994 );
3995 if (ret)
3996 goto end;
3997
3998 ret = lttng_metadata_printf(session,
3999 "typealias integer {\n"
4000 " size = 27; align = 1; signed = false;\n"
4001 " map = clock.%s.value;\n"
4002 "} := uint27_clock_monotonic_t;\n"
4003 "\n"
4004 "typealias integer {\n"
4005 " size = 32; align = %u; signed = false;\n"
4006 " map = clock.%s.value;\n"
4007 "} := uint32_clock_monotonic_t;\n"
4008 "\n"
4009 "typealias integer {\n"
4010 " size = 64; align = %u; signed = false;\n"
4011 " map = clock.%s.value;\n"
4012 "} := uint64_clock_monotonic_t;\n\n",
4013 trace_clock_name(),
4014 lttng_alignof(uint32_t) * CHAR_BIT,
4015 trace_clock_name(),
4016 lttng_alignof(uint64_t) * CHAR_BIT,
4017 trace_clock_name()
4018 );
4019 if (ret)
4020 goto end;
4021
4022 ret = _lttng_stream_packet_context_declare(session);
4023 if (ret)
4024 goto end;
4025
4026 ret = _lttng_event_header_declare(session);
4027 if (ret)
4028 goto end;
4029
4030 skip_session:
4031 list_for_each_entry(chan_priv, &session->priv->chan, node) {
4032 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
4033 if (ret)
4034 goto end;
4035 }
4036
4037 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
4038 ret = _lttng_event_metadata_statedump(session, event_recorder_priv->pub->chan,
4039 event_recorder_priv->pub);
4040 if (ret)
4041 goto end;
4042 }
4043 session->priv->metadata_dumped = 1;
4044 end:
4045 lttng_metadata_end(session);
4046 return ret;
4047 }
4048
4049 /**
4050 * lttng_transport_register - LTT transport registration
4051 * @transport: transport structure
4052 *
4053 * Registers a transport which can be used as output to extract the data out of
4054 * LTTng. The module calling this registration function must ensure that no
4055 * trap-inducing code will be executed by the transport functions. E.g.
4056 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
4057 * is made visible to the transport function. This registration acts as a
4058 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
4059 * after its registration must it synchronize the TLBs.
4060 */
4061 void lttng_transport_register(struct lttng_transport *transport)
4062 {
4063 /*
4064 * Make sure no page fault can be triggered by the module about to be
4065 * registered. We deal with this here so we don't have to call
4066 * vmalloc_sync_mappings() in each module's init.
4067 */
4068 wrapper_vmalloc_sync_mappings();
4069
4070 mutex_lock(&sessions_mutex);
4071 list_add_tail(&transport->node, &lttng_transport_list);
4072 mutex_unlock(&sessions_mutex);
4073 }
4074 EXPORT_SYMBOL_GPL(lttng_transport_register);
4075
4076 /**
4077 * lttng_transport_unregister - LTT transport unregistration
4078 * @transport: transport structure
4079 */
4080 void lttng_transport_unregister(struct lttng_transport *transport)
4081 {
4082 mutex_lock(&sessions_mutex);
4083 list_del(&transport->node);
4084 mutex_unlock(&sessions_mutex);
4085 }
4086 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4087
4088 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4089 {
4090 /*
4091 * Make sure no page fault can be triggered by the module about to be
4092 * registered. We deal with this here so we don't have to call
4093 * vmalloc_sync_mappings() in each module's init.
4094 */
4095 wrapper_vmalloc_sync_mappings();
4096
4097 mutex_lock(&sessions_mutex);
4098 list_add_tail(&transport->node, &lttng_counter_transport_list);
4099 mutex_unlock(&sessions_mutex);
4100 }
4101 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4102
4103 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4104 {
4105 mutex_lock(&sessions_mutex);
4106 list_del(&transport->node);
4107 mutex_unlock(&sessions_mutex);
4108 }
4109 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4110
4111 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4112
4113 enum cpuhp_state lttng_hp_prepare;
4114 enum cpuhp_state lttng_hp_online;
4115
4116 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4117 {
4118 struct lttng_cpuhp_node *lttng_node;
4119
4120 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4121 switch (lttng_node->component) {
4122 case LTTNG_RING_BUFFER_FRONTEND:
4123 return 0;
4124 case LTTNG_RING_BUFFER_BACKEND:
4125 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4126 case LTTNG_RING_BUFFER_ITER:
4127 return 0;
4128 case LTTNG_CONTEXT_PERF_COUNTERS:
4129 return 0;
4130 default:
4131 return -EINVAL;
4132 }
4133 }
4134
4135 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4136 {
4137 struct lttng_cpuhp_node *lttng_node;
4138
4139 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4140 switch (lttng_node->component) {
4141 case LTTNG_RING_BUFFER_FRONTEND:
4142 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4143 case LTTNG_RING_BUFFER_BACKEND:
4144 return 0;
4145 case LTTNG_RING_BUFFER_ITER:
4146 return 0;
4147 case LTTNG_CONTEXT_PERF_COUNTERS:
4148 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4149 default:
4150 return -EINVAL;
4151 }
4152 }
4153
4154 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4155 {
4156 struct lttng_cpuhp_node *lttng_node;
4157
4158 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4159 switch (lttng_node->component) {
4160 case LTTNG_RING_BUFFER_FRONTEND:
4161 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4162 case LTTNG_RING_BUFFER_BACKEND:
4163 return 0;
4164 case LTTNG_RING_BUFFER_ITER:
4165 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4166 case LTTNG_CONTEXT_PERF_COUNTERS:
4167 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4168 default:
4169 return -EINVAL;
4170 }
4171 }
4172
4173 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4174 {
4175 struct lttng_cpuhp_node *lttng_node;
4176
4177 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4178 switch (lttng_node->component) {
4179 case LTTNG_RING_BUFFER_FRONTEND:
4180 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4181 case LTTNG_RING_BUFFER_BACKEND:
4182 return 0;
4183 case LTTNG_RING_BUFFER_ITER:
4184 return 0;
4185 case LTTNG_CONTEXT_PERF_COUNTERS:
4186 return 0;
4187 default:
4188 return -EINVAL;
4189 }
4190 }
4191
4192 static int __init lttng_init_cpu_hotplug(void)
4193 {
4194 int ret;
4195
4196 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4197 lttng_hotplug_prepare,
4198 lttng_hotplug_dead);
4199 if (ret < 0) {
4200 return ret;
4201 }
4202 lttng_hp_prepare = ret;
4203 lttng_rb_set_hp_prepare(ret);
4204
4205 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4206 lttng_hotplug_online,
4207 lttng_hotplug_offline);
4208 if (ret < 0) {
4209 cpuhp_remove_multi_state(lttng_hp_prepare);
4210 lttng_hp_prepare = 0;
4211 return ret;
4212 }
4213 lttng_hp_online = ret;
4214 lttng_rb_set_hp_online(ret);
4215
4216 return 0;
4217 }
4218
4219 static void __exit lttng_exit_cpu_hotplug(void)
4220 {
4221 lttng_rb_set_hp_online(0);
4222 cpuhp_remove_multi_state(lttng_hp_online);
4223 lttng_rb_set_hp_prepare(0);
4224 cpuhp_remove_multi_state(lttng_hp_prepare);
4225 }
4226
4227 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4228 static int lttng_init_cpu_hotplug(void)
4229 {
4230 return 0;
4231 }
4232 static void lttng_exit_cpu_hotplug(void)
4233 {
4234 }
4235 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4236
4237 static int __init lttng_events_init(void)
4238 {
4239 int ret;
4240
4241 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4242 if (ret)
4243 return ret;
4244 ret = wrapper_get_pfnblock_flags_mask_init();
4245 if (ret)
4246 return ret;
4247 ret = wrapper_get_pageblock_flags_mask_init();
4248 if (ret)
4249 return ret;
4250 ret = lttng_probes_init();
4251 if (ret)
4252 return ret;
4253 ret = lttng_context_init();
4254 if (ret)
4255 return ret;
4256 ret = lttng_tracepoint_init();
4257 if (ret)
4258 goto error_tp;
4259 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4260 if (!event_recorder_cache) {
4261 ret = -ENOMEM;
4262 goto error_kmem_event_recorder;
4263 }
4264 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4265 if (!event_recorder_private_cache) {
4266 ret = -ENOMEM;
4267 goto error_kmem_event_recorder_private;
4268 }
4269 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4270 if (!event_notifier_cache) {
4271 ret = -ENOMEM;
4272 goto error_kmem_event_notifier;
4273 }
4274 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4275 if (!event_notifier_private_cache) {
4276 ret = -ENOMEM;
4277 goto error_kmem_event_notifier_private;
4278 }
4279 ret = lttng_abi_init();
4280 if (ret)
4281 goto error_abi;
4282 ret = lttng_logger_init();
4283 if (ret)
4284 goto error_logger;
4285 ret = lttng_init_cpu_hotplug();
4286 if (ret)
4287 goto error_hotplug;
4288 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4289 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4290 __stringify(LTTNG_MODULES_MINOR_VERSION),
4291 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4292 LTTNG_MODULES_EXTRAVERSION,
4293 LTTNG_VERSION_NAME,
4294 #ifdef LTTNG_EXTRA_VERSION_GIT
4295 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4296 #else
4297 "",
4298 #endif
4299 #ifdef LTTNG_EXTRA_VERSION_NAME
4300 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4301 #else
4302 "");
4303 #endif
4304 #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
4305 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
4306 #endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
4307 return 0;
4308
4309 error_hotplug:
4310 lttng_logger_exit();
4311 error_logger:
4312 lttng_abi_exit();
4313 error_abi:
4314 kmem_cache_destroy(event_notifier_private_cache);
4315 error_kmem_event_notifier_private:
4316 kmem_cache_destroy(event_notifier_cache);
4317 error_kmem_event_notifier:
4318 kmem_cache_destroy(event_recorder_private_cache);
4319 error_kmem_event_recorder_private:
4320 kmem_cache_destroy(event_recorder_cache);
4321 error_kmem_event_recorder:
4322 lttng_tracepoint_exit();
4323 error_tp:
4324 lttng_context_exit();
4325 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4326 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4327 __stringify(LTTNG_MODULES_MINOR_VERSION),
4328 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4329 LTTNG_MODULES_EXTRAVERSION,
4330 LTTNG_VERSION_NAME,
4331 #ifdef LTTNG_EXTRA_VERSION_GIT
4332 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4333 #else
4334 "",
4335 #endif
4336 #ifdef LTTNG_EXTRA_VERSION_NAME
4337 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4338 #else
4339 "");
4340 #endif
4341 return ret;
4342 }
4343
4344 module_init(lttng_events_init);
4345
4346 static void __exit lttng_events_exit(void)
4347 {
4348 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4349
4350 lttng_exit_cpu_hotplug();
4351 lttng_logger_exit();
4352 lttng_abi_exit();
4353 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4354 lttng_session_destroy(session_priv->pub);
4355 kmem_cache_destroy(event_recorder_cache);
4356 kmem_cache_destroy(event_recorder_private_cache);
4357 kmem_cache_destroy(event_notifier_cache);
4358 kmem_cache_destroy(event_notifier_private_cache);
4359 lttng_tracepoint_exit();
4360 lttng_context_exit();
4361 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4362 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4363 __stringify(LTTNG_MODULES_MINOR_VERSION),
4364 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4365 LTTNG_MODULES_EXTRAVERSION,
4366 LTTNG_VERSION_NAME,
4367 #ifdef LTTNG_EXTRA_VERSION_GIT
4368 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4369 #else
4370 "",
4371 #endif
4372 #ifdef LTTNG_EXTRA_VERSION_NAME
4373 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4374 #else
4375 "");
4376 #endif
4377 }
4378
4379 module_exit(lttng_events_exit);
4380
4381 #include <generated/patches.h>
4382 #ifdef LTTNG_EXTRA_VERSION_GIT
4383 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4384 #endif
4385 #ifdef LTTNG_EXTRA_VERSION_NAME
4386 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4387 #endif
4388 MODULE_LICENSE("GPL and additional rights");
4389 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4390 MODULE_DESCRIPTION("LTTng tracer");
4391 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4392 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4393 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4394 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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