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[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_capture(struct lttng_event_enabler_common *event_enabler,
2227 struct lttng_kernel_event_common *event)
2228 {
2229 switch (event_enabler->enabler_type) {
2230 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2231 break;
2232 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2233 {
2234 struct lttng_event_notifier_enabler *event_notifier_enabler =
2235 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2236 struct lttng_kernel_event_notifier *event_notifier =
2237 container_of(event, struct lttng_kernel_event_notifier, parent);
2238
2239 /* Link capture bytecodes if not linked yet. */
2240 lttng_enabler_link_bytecode(event->priv->desc,
2241 lttng_static_ctx, &event_notifier->priv->capture_bytecode_runtime_head,
2242 &event_notifier_enabler->capture_bytecode_head);
2243 event_notifier->priv->num_captures = event_notifier_enabler->num_captures;
2244 break;
2245 }
2246 default:
2247 WARN_ON_ONCE(1);
2248 }
2249 }
2250
2251 /*
2252 * Create events associated with an event_enabler (if not already present),
2253 * and add backward reference from the event to the enabler.
2254 * Should be called with sessions mutex held.
2255 */
2256 static
2257 int lttng_event_enabler_ref_events(struct lttng_event_recorder_enabler *event_enabler)
2258 {
2259 struct lttng_event_enabler_common *base_enabler = lttng_event_recorder_enabler_as_enabler(event_enabler);
2260 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2261 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(&event_enabler->parent);
2262
2263 lttng_syscall_table_set_wildcard_all(base_enabler);
2264
2265 /* First ensure that probe events are created for this enabler. */
2266 lttng_create_event_if_missing(&event_enabler->parent);
2267
2268 /* For each event matching event_enabler in session event list. */
2269 list_for_each_entry(event_recorder_priv, event_list_head, parent.node) {
2270 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2271 struct lttng_enabler_ref *enabler_ref;
2272
2273 if (!lttng_event_enabler_match_event(&event_enabler->parent, &event_recorder->parent))
2274 continue;
2275 enabler_ref = lttng_enabler_ref(&event_recorder_priv->parent.enablers_ref_head,
2276 lttng_event_recorder_enabler_as_enabler(event_enabler));
2277 if (!enabler_ref) {
2278 /*
2279 * If no backward ref, create it.
2280 * Add backward ref from event to event_enabler.
2281 */
2282 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2283 if (!enabler_ref)
2284 return -ENOMEM;
2285 enabler_ref->ref = lttng_event_recorder_enabler_as_enabler(event_enabler);
2286 list_add(&enabler_ref->node,
2287 &event_recorder_priv->parent.enablers_ref_head);
2288 }
2289
2290 /*
2291 * Link filter bytecodes if not linked yet.
2292 */
2293 lttng_enabler_link_bytecode(event_recorder_priv->parent.desc,
2294 lttng_static_ctx,
2295 &event_recorder_priv->parent.filter_bytecode_runtime_head,
2296 &lttng_event_recorder_enabler_as_enabler(event_enabler)->filter_bytecode_head);
2297 }
2298 return 0;
2299 }
2300
2301 /*
2302 * Create event_notifiers associated with a event_notifier enabler (if not already present).
2303 */
2304 static
2305 int lttng_event_notifier_enabler_ref_event_notifiers(
2306 struct lttng_event_notifier_enabler *event_notifier_enabler)
2307 {
2308 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2309 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(&event_notifier_enabler->parent);
2310
2311 lttng_syscall_table_set_wildcard_all(&event_notifier_enabler->parent);
2312
2313 /* First ensure that probe event_notifiers are created for this enabler. */
2314 lttng_create_event_if_missing(&event_notifier_enabler->parent);
2315
2316 /* Link the created event_notifier with its associated enabler. */
2317 list_for_each_entry(event_notifier_priv, event_list_head, parent.node) {
2318 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2319 struct lttng_enabler_ref *enabler_ref;
2320
2321 if (!lttng_event_enabler_match_event(&event_notifier_enabler->parent, &event_notifier->parent))
2322 continue;
2323
2324 enabler_ref = lttng_enabler_ref(&event_notifier_priv->parent.enablers_ref_head,
2325 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
2326 if (!enabler_ref) {
2327 /*
2328 * If no backward ref, create it.
2329 * Add backward ref from event_notifier to enabler.
2330 */
2331 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2332 if (!enabler_ref)
2333 return -ENOMEM;
2334
2335 enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
2336 event_notifier_enabler);
2337 list_add(&enabler_ref->node,
2338 &event_notifier_priv->parent.enablers_ref_head);
2339 }
2340
2341 /*
2342 * Link filter bytecodes if not linked yet.
2343 */
2344 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
2345 lttng_static_ctx, &event_notifier_priv->parent.filter_bytecode_runtime_head,
2346 &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
2347
2348 lttng_event_enabler_init_event_capture(&event_notifier_enabler->parent, &event_notifier->parent);
2349 }
2350 return 0;
2351 }
2352
2353 /*
2354 * Called at module load: connect the probe on all enablers matching
2355 * this event.
2356 * Called with sessions lock held.
2357 */
2358 int lttng_fix_pending_events(void)
2359 {
2360 struct lttng_kernel_session_private *session_priv;
2361
2362 list_for_each_entry(session_priv, &sessions, list)
2363 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2364 return 0;
2365 }
2366
2367 static bool lttng_event_notifier_group_has_active_event_notifiers(
2368 struct lttng_event_notifier_group *event_notifier_group)
2369 {
2370 struct lttng_event_notifier_enabler *event_notifier_enabler;
2371
2372 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head,
2373 node) {
2374 if (event_notifier_enabler->parent.enabled)
2375 return true;
2376 }
2377 return false;
2378 }
2379
2380 bool lttng_event_notifier_active(void)
2381 {
2382 struct lttng_event_notifier_group *event_notifier_group;
2383
2384 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2385 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2386 return true;
2387 }
2388 return false;
2389 }
2390
2391 int lttng_fix_pending_event_notifiers(void)
2392 {
2393 struct lttng_event_notifier_group *event_notifier_group;
2394
2395 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2396 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2397 return 0;
2398 }
2399
2400 struct lttng_event_recorder_enabler *lttng_event_recorder_enabler_create(
2401 enum lttng_enabler_format_type format_type,
2402 struct lttng_kernel_abi_event *event_param,
2403 struct lttng_kernel_channel_buffer *chan)
2404 {
2405 struct lttng_event_recorder_enabler *event_enabler;
2406
2407 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2408 if (!event_enabler)
2409 return NULL;
2410 event_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_RECORDER;
2411 event_enabler->parent.format_type = format_type;
2412 INIT_LIST_HEAD(&event_enabler->parent.filter_bytecode_head);
2413 memcpy(&event_enabler->parent.event_param, event_param,
2414 sizeof(event_enabler->parent.event_param));
2415 event_enabler->chan = chan;
2416 /* ctx left NULL */
2417 event_enabler->parent.enabled = 0;
2418 return event_enabler;
2419 }
2420
2421 void lttng_event_enabler_session_add(struct lttng_kernel_session *session,
2422 struct lttng_event_recorder_enabler *event_enabler)
2423 {
2424 mutex_lock(&sessions_mutex);
2425 list_add(&event_enabler->node, &session->priv->enablers_head);
2426 event_enabler->published = true;
2427 lttng_session_lazy_sync_event_enablers(session);
2428 mutex_unlock(&sessions_mutex);
2429 }
2430
2431 int lttng_event_enabler_enable(struct lttng_event_enabler_common *event_enabler)
2432 {
2433 mutex_lock(&sessions_mutex);
2434 event_enabler->enabled = 1;
2435 lttng_event_enabler_sync(event_enabler);
2436 mutex_unlock(&sessions_mutex);
2437 return 0;
2438 }
2439
2440 int lttng_event_enabler_disable(struct lttng_event_enabler_common *event_enabler)
2441 {
2442 mutex_lock(&sessions_mutex);
2443 event_enabler->enabled = 0;
2444 lttng_event_enabler_sync(event_enabler);
2445 mutex_unlock(&sessions_mutex);
2446 return 0;
2447 }
2448
2449 static
2450 int lttng_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *enabler,
2451 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2452 {
2453 struct lttng_kernel_bytecode_node *bytecode_node;
2454 uint32_t bytecode_len;
2455 int ret;
2456
2457 ret = get_user(bytecode_len, &bytecode->len);
2458 if (ret)
2459 return ret;
2460 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2461 GFP_KERNEL);
2462 if (!bytecode_node)
2463 return -ENOMEM;
2464 ret = copy_from_user(&bytecode_node->bc, bytecode,
2465 sizeof(*bytecode) + bytecode_len);
2466 if (ret)
2467 goto error_free;
2468
2469 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2470 bytecode_node->enabler = enabler;
2471 /* Enforce length based on allocated size */
2472 bytecode_node->bc.len = bytecode_len;
2473 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2474
2475 return 0;
2476
2477 error_free:
2478 lttng_kvfree(bytecode_node);
2479 return ret;
2480 }
2481
2482 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *event_enabler,
2483 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2484 {
2485 int ret;
2486 ret = lttng_enabler_attach_filter_bytecode(event_enabler, bytecode);
2487 if (ret)
2488 goto error;
2489 lttng_event_enabler_sync(event_enabler);
2490 return 0;
2491
2492 error:
2493 return ret;
2494 }
2495
2496 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2497 struct lttng_kernel_abi_event_callsite __user *callsite)
2498 {
2499
2500 switch (event->priv->instrumentation) {
2501 case LTTNG_KERNEL_ABI_UPROBE:
2502 return lttng_uprobes_event_add_callsite(event, callsite);
2503 default:
2504 return -EINVAL;
2505 }
2506 }
2507
2508 static
2509 void lttng_enabler_destroy(struct lttng_event_enabler_common *enabler)
2510 {
2511 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2512
2513 /* Destroy filter bytecode */
2514 list_for_each_entry_safe(filter_node, tmp_filter_node,
2515 &enabler->filter_bytecode_head, node) {
2516 lttng_kvfree(filter_node);
2517 }
2518 }
2519
2520 void lttng_event_enabler_destroy(struct lttng_event_enabler_common *event_enabler)
2521 {
2522 switch (event_enabler->enabler_type) {
2523 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2524 {
2525 struct lttng_event_recorder_enabler *event_recorder_enabler =
2526 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2527
2528 lttng_enabler_destroy(event_enabler);
2529 if (event_recorder_enabler->published)
2530 list_del(&event_recorder_enabler->node);
2531 kfree(event_recorder_enabler);
2532 break;
2533 }
2534 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2535 {
2536 struct lttng_event_notifier_enabler *event_notifier_enabler =
2537 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2538
2539 lttng_enabler_destroy(event_enabler);
2540 if (event_notifier_enabler->published)
2541 list_del(&event_notifier_enabler->node);
2542 kfree(event_notifier_enabler);
2543 break;
2544 }
2545 default:
2546 WARN_ON_ONCE(1);
2547 }
2548 }
2549
2550 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2551 enum lttng_enabler_format_type format_type,
2552 struct lttng_kernel_abi_event_notifier *event_notifier_param,
2553 struct lttng_event_notifier_group *event_notifier_group)
2554 {
2555 struct lttng_event_notifier_enabler *event_notifier_enabler;
2556
2557 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2558 if (!event_notifier_enabler)
2559 return NULL;
2560
2561 event_notifier_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_NOTIFIER;
2562 event_notifier_enabler->parent.format_type = format_type;
2563 INIT_LIST_HEAD(&event_notifier_enabler->parent.filter_bytecode_head);
2564 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2565
2566 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2567 event_notifier_enabler->num_captures = 0;
2568
2569 memcpy(&event_notifier_enabler->parent.event_param, &event_notifier_param->event,
2570 sizeof(event_notifier_enabler->parent.event_param));
2571
2572 event_notifier_enabler->parent.enabled = 0;
2573 event_notifier_enabler->parent.user_token = event_notifier_param->event.token;
2574 event_notifier_enabler->group = event_notifier_group;
2575 return event_notifier_enabler;
2576 }
2577
2578 void lttng_event_notifier_enabler_group_add(struct lttng_event_notifier_group *event_notifier_group,
2579 struct lttng_event_notifier_enabler *event_notifier_enabler)
2580 {
2581 mutex_lock(&sessions_mutex);
2582 list_add(&event_notifier_enabler->node, &event_notifier_enabler->group->enablers_head);
2583 event_notifier_enabler->published = true;
2584 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2585 mutex_unlock(&sessions_mutex);
2586 }
2587
2588 int lttng_event_notifier_enabler_enable(
2589 struct lttng_event_notifier_enabler *event_notifier_enabler)
2590 {
2591 mutex_lock(&sessions_mutex);
2592 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2593 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2594 mutex_unlock(&sessions_mutex);
2595 return 0;
2596 }
2597
2598 int lttng_event_notifier_enabler_disable(
2599 struct lttng_event_notifier_enabler *event_notifier_enabler)
2600 {
2601 mutex_lock(&sessions_mutex);
2602 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2603 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2604 mutex_unlock(&sessions_mutex);
2605 return 0;
2606 }
2607
2608 int lttng_event_notifier_enabler_attach_capture_bytecode(
2609 struct lttng_event_notifier_enabler *event_notifier_enabler,
2610 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2611 {
2612 struct lttng_kernel_bytecode_node *bytecode_node;
2613 struct lttng_event_enabler_common *enabler =
2614 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2615 uint32_t bytecode_len;
2616 int ret;
2617
2618 ret = get_user(bytecode_len, &bytecode->len);
2619 if (ret)
2620 return ret;
2621
2622 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2623 GFP_KERNEL);
2624 if (!bytecode_node)
2625 return -ENOMEM;
2626
2627 ret = copy_from_user(&bytecode_node->bc, bytecode,
2628 sizeof(*bytecode) + bytecode_len);
2629 if (ret)
2630 goto error_free;
2631
2632 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2633 bytecode_node->enabler = enabler;
2634
2635 /* Enforce length based on allocated size */
2636 bytecode_node->bc.len = bytecode_len;
2637 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2638
2639 event_notifier_enabler->num_captures++;
2640
2641 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2642 goto end;
2643
2644 error_free:
2645 lttng_kvfree(bytecode_node);
2646 end:
2647 return ret;
2648 }
2649
2650 /*
2651 * lttng_session_sync_event_enablers should be called just before starting a
2652 * session.
2653 * Should be called with sessions mutex held.
2654 */
2655 static
2656 void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2657 {
2658 struct lttng_event_recorder_enabler *event_enabler;
2659 struct lttng_kernel_event_recorder_private *event_recorder_priv;
2660
2661 list_for_each_entry(event_enabler, &session->priv->enablers_head, node)
2662 lttng_event_enabler_ref_events(event_enabler);
2663 /*
2664 * For each event, if at least one of its enablers is enabled,
2665 * and its channel and session transient states are enabled, we
2666 * enable the event, else we disable it.
2667 */
2668 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
2669 struct lttng_kernel_event_recorder *event_recorder = event_recorder_priv->pub;
2670 struct lttng_enabler_ref *enabler_ref;
2671 struct lttng_kernel_bytecode_runtime *runtime;
2672 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2673 int nr_filters = 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 /* Check if has enablers without bytecode enabled */
2712 list_for_each_entry(enabler_ref,
2713 &event_recorder_priv->parent.enablers_ref_head, node) {
2714 if (enabler_ref->ref->enabled
2715 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2716 has_enablers_without_filter_bytecode = 1;
2717 break;
2718 }
2719 }
2720 event_recorder_priv->parent.has_enablers_without_filter_bytecode =
2721 has_enablers_without_filter_bytecode;
2722
2723 /* Enable filters */
2724 list_for_each_entry(runtime,
2725 &event_recorder_priv->parent.filter_bytecode_runtime_head, node) {
2726 lttng_bytecode_sync_state(runtime);
2727 nr_filters++;
2728 }
2729 WRITE_ONCE(event_recorder_priv->parent.pub->eval_filter,
2730 !(has_enablers_without_filter_bytecode || !nr_filters));
2731 }
2732 }
2733
2734 /*
2735 * Apply enablers to session events, adding events to session if need
2736 * be. It is required after each modification applied to an active
2737 * session, and right before session "start".
2738 * "lazy" sync means we only sync if required.
2739 * Should be called with sessions mutex held.
2740 */
2741 static
2742 void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2743 {
2744 /* We can skip if session is not active */
2745 if (!session->active)
2746 return;
2747 lttng_session_sync_event_enablers(session);
2748 }
2749
2750 static
2751 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2752 {
2753 struct lttng_event_notifier_enabler *event_notifier_enabler;
2754 struct lttng_kernel_event_notifier_private *event_notifier_priv;
2755
2756 list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
2757 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
2758
2759 /*
2760 * For each event_notifier, if at least one of its enablers is enabled,
2761 * we enable the event_notifier, else we disable it.
2762 */
2763 list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, parent.node) {
2764 struct lttng_kernel_event_notifier *event_notifier = event_notifier_priv->pub;
2765 struct lttng_enabler_ref *enabler_ref;
2766 struct lttng_kernel_bytecode_runtime *runtime;
2767 int enabled = 0, has_enablers_without_filter_bytecode = 0;
2768 int nr_filters = 0, nr_captures = 0;
2769
2770 switch (event_notifier_priv->parent.instrumentation) {
2771 case LTTNG_KERNEL_ABI_TRACEPOINT:
2772 lttng_fallthrough;
2773 case LTTNG_KERNEL_ABI_SYSCALL:
2774 /* Enable event_notifiers */
2775 list_for_each_entry(enabler_ref,
2776 &event_notifier_priv->parent.enablers_ref_head, node) {
2777 if (enabler_ref->ref->enabled) {
2778 enabled = 1;
2779 break;
2780 }
2781 }
2782 break;
2783
2784 default:
2785 /* Not handled with sync. */
2786 continue;
2787 }
2788
2789 WRITE_ONCE(event_notifier->parent.enabled, enabled);
2790 /*
2791 * Sync tracepoint registration with event_notifier enabled
2792 * state.
2793 */
2794 if (enabled) {
2795 if (!event_notifier_priv->parent.registered)
2796 register_event(&event_notifier->parent);
2797 } else {
2798 if (event_notifier_priv->parent.registered)
2799 _lttng_event_unregister(&event_notifier->parent);
2800 }
2801
2802 /* Check if has enablers without bytecode enabled */
2803 list_for_each_entry(enabler_ref,
2804 &event_notifier_priv->parent.enablers_ref_head, node) {
2805 if (enabler_ref->ref->enabled
2806 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2807 has_enablers_without_filter_bytecode = 1;
2808 break;
2809 }
2810 }
2811 event_notifier_priv->parent.has_enablers_without_filter_bytecode =
2812 has_enablers_without_filter_bytecode;
2813
2814 /* Enable filters */
2815 list_for_each_entry(runtime,
2816 &event_notifier_priv->parent.filter_bytecode_runtime_head, node) {
2817 lttng_bytecode_sync_state(runtime);
2818 nr_filters++;
2819 }
2820 WRITE_ONCE(event_notifier_priv->parent.pub->eval_filter,
2821 !(has_enablers_without_filter_bytecode || !nr_filters));
2822
2823 /* Enable captures */
2824 list_for_each_entry(runtime,
2825 &event_notifier_priv->capture_bytecode_runtime_head, node) {
2826 lttng_bytecode_sync_state(runtime);
2827 nr_captures++;
2828 }
2829 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2830 }
2831 }
2832
2833 static
2834 void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler)
2835 {
2836 switch (event_enabler->enabler_type) {
2837 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2838 {
2839 struct lttng_event_recorder_enabler *event_recorder_enabler =
2840 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2841 lttng_session_lazy_sync_event_enablers(event_recorder_enabler->chan->parent.session);
2842 break;
2843 }
2844 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2845 {
2846 struct lttng_event_notifier_enabler *event_notifier_enabler =
2847 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2848 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2849 break;
2850 }
2851 default:
2852 WARN_ON_ONCE(1);
2853 }
2854 }
2855
2856 /*
2857 * Serialize at most one packet worth of metadata into a metadata
2858 * channel.
2859 * We grab the metadata cache mutex to get exclusive access to our metadata
2860 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2861 * allows us to do racy operations such as looking for remaining space left in
2862 * packet and write, since mutual exclusion protects us from concurrent writes.
2863 * Mutual exclusion on the metadata cache allow us to read the cache content
2864 * without racing against reallocation of the cache by updates.
2865 * Returns the number of bytes written in the channel, 0 if no data
2866 * was written and a negative value on error.
2867 */
2868 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2869 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2870 {
2871 struct lttng_kernel_ring_buffer_ctx ctx;
2872 int ret = 0;
2873 size_t len, reserve_len;
2874
2875 /*
2876 * Ensure we support mutiple get_next / put sequences followed by
2877 * put_next. The metadata cache lock protects reading the metadata
2878 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2879 * "flush" operations on the buffer invoked by different processes.
2880 * Moreover, since the metadata cache memory can be reallocated, we
2881 * need to have exclusive access against updates even though we only
2882 * read it.
2883 */
2884 mutex_lock(&stream->metadata_cache->lock);
2885 WARN_ON(stream->metadata_in < stream->metadata_out);
2886 if (stream->metadata_in != stream->metadata_out)
2887 goto end;
2888
2889 /* Metadata regenerated, change the version. */
2890 if (stream->metadata_cache->version != stream->version)
2891 stream->version = stream->metadata_cache->version;
2892
2893 len = stream->metadata_cache->metadata_written -
2894 stream->metadata_in;
2895 if (!len)
2896 goto end;
2897 reserve_len = min_t(size_t,
2898 stream->transport->ops.priv->packet_avail_size(chan),
2899 len);
2900 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2901 sizeof(char), NULL);
2902 /*
2903 * If reservation failed, return an error to the caller.
2904 */
2905 ret = stream->transport->ops.event_reserve(&ctx);
2906 if (ret != 0) {
2907 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2908 stream->coherent = false;
2909 goto end;
2910 }
2911 stream->transport->ops.event_write(&ctx,
2912 stream->metadata_cache->data + stream->metadata_in,
2913 reserve_len, 1);
2914 stream->transport->ops.event_commit(&ctx);
2915 stream->metadata_in += reserve_len;
2916 if (reserve_len < len)
2917 stream->coherent = false;
2918 else
2919 stream->coherent = true;
2920 ret = reserve_len;
2921
2922 end:
2923 if (coherent)
2924 *coherent = stream->coherent;
2925 mutex_unlock(&stream->metadata_cache->lock);
2926 return ret;
2927 }
2928
2929 static
2930 void lttng_metadata_begin(struct lttng_kernel_session *session)
2931 {
2932 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
2933 mutex_lock(&session->priv->metadata_cache->lock);
2934 }
2935
2936 static
2937 void lttng_metadata_end(struct lttng_kernel_session *session)
2938 {
2939 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2940 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
2941 struct lttng_metadata_stream *stream;
2942
2943 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
2944 wake_up_interruptible(&stream->read_wait);
2945 mutex_unlock(&session->priv->metadata_cache->lock);
2946 }
2947 }
2948
2949 /*
2950 * Write the metadata to the metadata cache.
2951 * Must be called with sessions_mutex held.
2952 * The metadata cache lock protects us from concurrent read access from
2953 * thread outputting metadata content to ring buffer.
2954 * The content of the printf is printed as a single atomic metadata
2955 * transaction.
2956 */
2957 int lttng_metadata_printf(struct lttng_kernel_session *session,
2958 const char *fmt, ...)
2959 {
2960 char *str;
2961 size_t len;
2962 va_list ap;
2963
2964 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
2965
2966 va_start(ap, fmt);
2967 str = kvasprintf(GFP_KERNEL, fmt, ap);
2968 va_end(ap);
2969 if (!str)
2970 return -ENOMEM;
2971
2972 len = strlen(str);
2973 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
2974 if (session->priv->metadata_cache->metadata_written + len >
2975 session->priv->metadata_cache->cache_alloc) {
2976 char *tmp_cache_realloc;
2977 unsigned int tmp_cache_alloc_size;
2978
2979 tmp_cache_alloc_size = max_t(unsigned int,
2980 session->priv->metadata_cache->cache_alloc + len,
2981 session->priv->metadata_cache->cache_alloc << 1);
2982 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
2983 if (!tmp_cache_realloc)
2984 goto err;
2985 if (session->priv->metadata_cache->data) {
2986 memcpy(tmp_cache_realloc,
2987 session->priv->metadata_cache->data,
2988 session->priv->metadata_cache->cache_alloc);
2989 vfree(session->priv->metadata_cache->data);
2990 }
2991
2992 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
2993 session->priv->metadata_cache->data = tmp_cache_realloc;
2994 }
2995 memcpy(session->priv->metadata_cache->data +
2996 session->priv->metadata_cache->metadata_written,
2997 str, len);
2998 session->priv->metadata_cache->metadata_written += len;
2999 kfree(str);
3000
3001 return 0;
3002
3003 err:
3004 kfree(str);
3005 return -ENOMEM;
3006 }
3007
3008 static
3009 int print_tabs(struct lttng_kernel_session *session, size_t nesting)
3010 {
3011 size_t i;
3012
3013 for (i = 0; i < nesting; i++) {
3014 int ret;
3015
3016 ret = lttng_metadata_printf(session, " ");
3017 if (ret) {
3018 return ret;
3019 }
3020 }
3021 return 0;
3022 }
3023
3024 static
3025 int lttng_field_name_statedump(struct lttng_kernel_session *session,
3026 const struct lttng_kernel_event_field *field,
3027 size_t nesting)
3028 {
3029 return lttng_metadata_printf(session, " _%s;\n", field->name);
3030 }
3031
3032 static
3033 int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
3034 const struct lttng_kernel_type_integer *type,
3035 enum lttng_kernel_string_encoding parent_encoding,
3036 size_t nesting)
3037 {
3038 int ret;
3039
3040 ret = print_tabs(session, nesting);
3041 if (ret)
3042 return ret;
3043 ret = lttng_metadata_printf(session,
3044 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
3045 type->size,
3046 type->alignment,
3047 type->signedness,
3048 (parent_encoding == lttng_kernel_string_encoding_none)
3049 ? "none"
3050 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
3051 ? "UTF8"
3052 : "ASCII",
3053 type->base,
3054 #if __BYTE_ORDER == __BIG_ENDIAN
3055 type->reverse_byte_order ? " byte_order = le;" : ""
3056 #else
3057 type->reverse_byte_order ? " byte_order = be;" : ""
3058 #endif
3059 );
3060 return ret;
3061 }
3062
3063 /*
3064 * Must be called with sessions_mutex held.
3065 */
3066 static
3067 int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
3068 const struct lttng_kernel_type_struct *type,
3069 size_t nesting)
3070 {
3071 const char *prev_field_name = NULL;
3072 int ret;
3073 uint32_t i, nr_fields;
3074 unsigned int alignment;
3075
3076 ret = print_tabs(session, nesting);
3077 if (ret)
3078 return ret;
3079 ret = lttng_metadata_printf(session,
3080 "struct {\n");
3081 if (ret)
3082 return ret;
3083 nr_fields = type->nr_fields;
3084 for (i = 0; i < nr_fields; i++) {
3085 const struct lttng_kernel_event_field *iter_field;
3086
3087 iter_field = type->fields[i];
3088 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
3089 if (ret)
3090 return ret;
3091 }
3092 ret = print_tabs(session, nesting);
3093 if (ret)
3094 return ret;
3095 alignment = type->alignment;
3096 if (alignment) {
3097 ret = lttng_metadata_printf(session,
3098 "} align(%u)",
3099 alignment);
3100 } else {
3101 ret = lttng_metadata_printf(session,
3102 "}");
3103 }
3104 return ret;
3105 }
3106
3107 /*
3108 * Must be called with sessions_mutex held.
3109 */
3110 static
3111 int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
3112 const struct lttng_kernel_event_field *field,
3113 size_t nesting)
3114 {
3115 int ret;
3116
3117 ret = _lttng_struct_type_statedump(session,
3118 lttng_kernel_get_type_struct(field->type), nesting);
3119 if (ret)
3120 return ret;
3121 return lttng_field_name_statedump(session, field, nesting);
3122 }
3123
3124 /*
3125 * Must be called with sessions_mutex held.
3126 */
3127 static
3128 int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
3129 const struct lttng_kernel_type_variant *type,
3130 size_t nesting,
3131 const char *prev_field_name)
3132 {
3133 const char *tag_name;
3134 int ret;
3135 uint32_t i, nr_choices;
3136
3137 tag_name = type->tag_name;
3138 if (!tag_name)
3139 tag_name = prev_field_name;
3140 if (!tag_name)
3141 return -EINVAL;
3142 /*
3143 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3144 */
3145 if (type->alignment != 0)
3146 return -EINVAL;
3147 ret = print_tabs(session, nesting);
3148 if (ret)
3149 return ret;
3150 ret = lttng_metadata_printf(session,
3151 "variant <_%s> {\n",
3152 tag_name);
3153 if (ret)
3154 return ret;
3155 nr_choices = type->nr_choices;
3156 for (i = 0; i < nr_choices; i++) {
3157 const struct lttng_kernel_event_field *iter_field;
3158
3159 iter_field = type->choices[i];
3160 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3161 if (ret)
3162 return ret;
3163 }
3164 ret = print_tabs(session, nesting);
3165 if (ret)
3166 return ret;
3167 ret = lttng_metadata_printf(session,
3168 "}");
3169 return ret;
3170 }
3171
3172 /*
3173 * Must be called with sessions_mutex held.
3174 */
3175 static
3176 int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3177 const struct lttng_kernel_event_field *field,
3178 size_t nesting,
3179 const char *prev_field_name)
3180 {
3181 int ret;
3182
3183 ret = _lttng_variant_type_statedump(session,
3184 lttng_kernel_get_type_variant(field->type), nesting,
3185 prev_field_name);
3186 if (ret)
3187 return ret;
3188 return lttng_field_name_statedump(session, field, nesting);
3189 }
3190
3191 /*
3192 * Must be called with sessions_mutex held.
3193 */
3194 static
3195 int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3196 const struct lttng_kernel_event_field *field,
3197 size_t nesting)
3198 {
3199 int ret;
3200 const struct lttng_kernel_type_array *array_type;
3201 const struct lttng_kernel_type_common *elem_type;
3202
3203 array_type = lttng_kernel_get_type_array(field->type);
3204 WARN_ON_ONCE(!array_type);
3205
3206 if (array_type->alignment) {
3207 ret = print_tabs(session, nesting);
3208 if (ret)
3209 return ret;
3210 ret = lttng_metadata_printf(session,
3211 "struct { } align(%u) _%s_padding;\n",
3212 array_type->alignment * CHAR_BIT,
3213 field->name);
3214 if (ret)
3215 return ret;
3216 }
3217 /*
3218 * Nested compound types: Only array of structures and variants are
3219 * currently supported.
3220 */
3221 elem_type = array_type->elem_type;
3222 switch (elem_type->type) {
3223 case lttng_kernel_type_integer:
3224 case lttng_kernel_type_struct:
3225 case lttng_kernel_type_variant:
3226 ret = _lttng_type_statedump(session, elem_type,
3227 array_type->encoding, nesting);
3228 if (ret)
3229 return ret;
3230 break;
3231
3232 default:
3233 return -EINVAL;
3234 }
3235 ret = lttng_metadata_printf(session,
3236 " _%s[%u];\n",
3237 field->name,
3238 array_type->length);
3239 return ret;
3240 }
3241
3242 /*
3243 * Must be called with sessions_mutex held.
3244 */
3245 static
3246 int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3247 const struct lttng_kernel_event_field *field,
3248 size_t nesting,
3249 const char *prev_field_name)
3250 {
3251 int ret;
3252 const char *length_name;
3253 const struct lttng_kernel_type_sequence *sequence_type;
3254 const struct lttng_kernel_type_common *elem_type;
3255
3256 sequence_type = lttng_kernel_get_type_sequence(field->type);
3257 WARN_ON_ONCE(!sequence_type);
3258
3259 length_name = sequence_type->length_name;
3260 if (!length_name)
3261 length_name = prev_field_name;
3262 if (!length_name)
3263 return -EINVAL;
3264
3265 if (sequence_type->alignment) {
3266 ret = print_tabs(session, nesting);
3267 if (ret)
3268 return ret;
3269 ret = lttng_metadata_printf(session,
3270 "struct { } align(%u) _%s_padding;\n",
3271 sequence_type->alignment * CHAR_BIT,
3272 field->name);
3273 if (ret)
3274 return ret;
3275 }
3276
3277 /*
3278 * Nested compound types: Only array of structures and variants are
3279 * currently supported.
3280 */
3281 elem_type = sequence_type->elem_type;
3282 switch (elem_type->type) {
3283 case lttng_kernel_type_integer:
3284 case lttng_kernel_type_struct:
3285 case lttng_kernel_type_variant:
3286 ret = _lttng_type_statedump(session, elem_type,
3287 sequence_type->encoding, nesting);
3288 if (ret)
3289 return ret;
3290 break;
3291
3292 default:
3293 return -EINVAL;
3294 }
3295 ret = lttng_metadata_printf(session,
3296 " _%s[ _%s ];\n",
3297 field->name,
3298 length_name);
3299 return ret;
3300 }
3301
3302 /*
3303 * Must be called with sessions_mutex held.
3304 */
3305 static
3306 int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3307 const struct lttng_kernel_type_enum *type,
3308 size_t nesting)
3309 {
3310 const struct lttng_kernel_enum_desc *enum_desc;
3311 const struct lttng_kernel_type_common *container_type;
3312 int ret;
3313 unsigned int i, nr_entries;
3314
3315 container_type = type->container_type;
3316 if (container_type->type != lttng_kernel_type_integer) {
3317 ret = -EINVAL;
3318 goto end;
3319 }
3320 enum_desc = type->desc;
3321 nr_entries = enum_desc->nr_entries;
3322
3323 ret = print_tabs(session, nesting);
3324 if (ret)
3325 goto end;
3326 ret = lttng_metadata_printf(session, "enum : ");
3327 if (ret)
3328 goto end;
3329 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3330 lttng_kernel_string_encoding_none, 0);
3331 if (ret)
3332 goto end;
3333 ret = lttng_metadata_printf(session, " {\n");
3334 if (ret)
3335 goto end;
3336 /* Dump all entries */
3337 for (i = 0; i < nr_entries; i++) {
3338 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3339 int j, len;
3340
3341 ret = print_tabs(session, nesting + 1);
3342 if (ret)
3343 goto end;
3344 ret = lttng_metadata_printf(session,
3345 "\"");
3346 if (ret)
3347 goto end;
3348 len = strlen(entry->string);
3349 /* Escape the character '"' */
3350 for (j = 0; j < len; j++) {
3351 char c = entry->string[j];
3352
3353 switch (c) {
3354 case '"':
3355 ret = lttng_metadata_printf(session,
3356 "\\\"");
3357 break;
3358 case '\\':
3359 ret = lttng_metadata_printf(session,
3360 "\\\\");
3361 break;
3362 default:
3363 ret = lttng_metadata_printf(session,
3364 "%c", c);
3365 break;
3366 }
3367 if (ret)
3368 goto end;
3369 }
3370 ret = lttng_metadata_printf(session, "\"");
3371 if (ret)
3372 goto end;
3373
3374 if (entry->options.is_auto) {
3375 ret = lttng_metadata_printf(session, ",\n");
3376 if (ret)
3377 goto end;
3378 } else {
3379 ret = lttng_metadata_printf(session,
3380 " = ");
3381 if (ret)
3382 goto end;
3383 if (entry->start.signedness)
3384 ret = lttng_metadata_printf(session,
3385 "%lld", (long long) entry->start.value);
3386 else
3387 ret = lttng_metadata_printf(session,
3388 "%llu", entry->start.value);
3389 if (ret)
3390 goto end;
3391 if (entry->start.signedness == entry->end.signedness &&
3392 entry->start.value
3393 == entry->end.value) {
3394 ret = lttng_metadata_printf(session,
3395 ",\n");
3396 } else {
3397 if (entry->end.signedness) {
3398 ret = lttng_metadata_printf(session,
3399 " ... %lld,\n",
3400 (long long) entry->end.value);
3401 } else {
3402 ret = lttng_metadata_printf(session,
3403 " ... %llu,\n",
3404 entry->end.value);
3405 }
3406 }
3407 if (ret)
3408 goto end;
3409 }
3410 }
3411 ret = print_tabs(session, nesting);
3412 if (ret)
3413 goto end;
3414 ret = lttng_metadata_printf(session, "}");
3415 end:
3416 return ret;
3417 }
3418
3419 /*
3420 * Must be called with sessions_mutex held.
3421 */
3422 static
3423 int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3424 const struct lttng_kernel_event_field *field,
3425 size_t nesting)
3426 {
3427 int ret;
3428 const struct lttng_kernel_type_enum *enum_type;
3429
3430 enum_type = lttng_kernel_get_type_enum(field->type);
3431 WARN_ON_ONCE(!enum_type);
3432 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3433 if (ret)
3434 return ret;
3435 return lttng_field_name_statedump(session, field, nesting);
3436 }
3437
3438 static
3439 int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3440 const struct lttng_kernel_event_field *field,
3441 size_t nesting)
3442 {
3443 int ret;
3444
3445 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3446 lttng_kernel_string_encoding_none, nesting);
3447 if (ret)
3448 return ret;
3449 return lttng_field_name_statedump(session, field, nesting);
3450 }
3451
3452 static
3453 int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3454 const struct lttng_kernel_type_string *type,
3455 size_t nesting)
3456 {
3457 int ret;
3458
3459 /* Default encoding is UTF8 */
3460 ret = print_tabs(session, nesting);
3461 if (ret)
3462 return ret;
3463 ret = lttng_metadata_printf(session,
3464 "string%s",
3465 type->encoding == lttng_kernel_string_encoding_ASCII ?
3466 " { encoding = ASCII; }" : "");
3467 return ret;
3468 }
3469
3470 static
3471 int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3472 const struct lttng_kernel_event_field *field,
3473 size_t nesting)
3474 {
3475 const struct lttng_kernel_type_string *string_type;
3476 int ret;
3477
3478 string_type = lttng_kernel_get_type_string(field->type);
3479 WARN_ON_ONCE(!string_type);
3480 ret = _lttng_string_type_statedump(session, string_type, nesting);
3481 if (ret)
3482 return ret;
3483 return lttng_field_name_statedump(session, field, nesting);
3484 }
3485
3486 /*
3487 * Must be called with sessions_mutex held.
3488 */
3489 static
3490 int _lttng_type_statedump(struct lttng_kernel_session *session,
3491 const struct lttng_kernel_type_common *type,
3492 enum lttng_kernel_string_encoding parent_encoding,
3493 size_t nesting)
3494 {
3495 int ret = 0;
3496
3497 switch (type->type) {
3498 case lttng_kernel_type_integer:
3499 ret = _lttng_integer_type_statedump(session,
3500 lttng_kernel_get_type_integer(type),
3501 parent_encoding, nesting);
3502 break;
3503 case lttng_kernel_type_enum:
3504 ret = _lttng_enum_type_statedump(session,
3505 lttng_kernel_get_type_enum(type),
3506 nesting);
3507 break;
3508 case lttng_kernel_type_string:
3509 ret = _lttng_string_type_statedump(session,
3510 lttng_kernel_get_type_string(type),
3511 nesting);
3512 break;
3513 case lttng_kernel_type_struct:
3514 ret = _lttng_struct_type_statedump(session,
3515 lttng_kernel_get_type_struct(type),
3516 nesting);
3517 break;
3518 case lttng_kernel_type_variant:
3519 ret = _lttng_variant_type_statedump(session,
3520 lttng_kernel_get_type_variant(type),
3521 nesting, NULL);
3522 break;
3523
3524 /* Nested arrays and sequences are not supported yet. */
3525 case lttng_kernel_type_array:
3526 case lttng_kernel_type_sequence:
3527 default:
3528 WARN_ON_ONCE(1);
3529 return -EINVAL;
3530 }
3531 return ret;
3532 }
3533
3534 /*
3535 * Must be called with sessions_mutex held.
3536 */
3537 static
3538 int _lttng_field_statedump(struct lttng_kernel_session *session,
3539 const struct lttng_kernel_event_field *field,
3540 size_t nesting,
3541 const char **prev_field_name_p)
3542 {
3543 const char *prev_field_name = NULL;
3544 int ret = 0;
3545
3546 if (prev_field_name_p)
3547 prev_field_name = *prev_field_name_p;
3548 switch (field->type->type) {
3549 case lttng_kernel_type_integer:
3550 ret = _lttng_integer_field_statedump(session, field, nesting);
3551 break;
3552 case lttng_kernel_type_enum:
3553 ret = _lttng_enum_field_statedump(session, field, nesting);
3554 break;
3555 case lttng_kernel_type_string:
3556 ret = _lttng_string_field_statedump(session, field, nesting);
3557 break;
3558 case lttng_kernel_type_struct:
3559 ret = _lttng_struct_field_statedump(session, field, nesting);
3560 break;
3561 case lttng_kernel_type_array:
3562 ret = _lttng_array_field_statedump(session, field, nesting);
3563 break;
3564 case lttng_kernel_type_sequence:
3565 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3566 break;
3567 case lttng_kernel_type_variant:
3568 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3569 break;
3570
3571 default:
3572 WARN_ON_ONCE(1);
3573 return -EINVAL;
3574 }
3575 if (prev_field_name_p)
3576 *prev_field_name_p = field->name;
3577 return ret;
3578 }
3579
3580 static
3581 int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3582 struct lttng_kernel_ctx *ctx)
3583 {
3584 const char *prev_field_name = NULL;
3585 int ret = 0;
3586 int i;
3587
3588 if (!ctx)
3589 return 0;
3590 for (i = 0; i < ctx->nr_fields; i++) {
3591 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3592
3593 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3594 if (ret)
3595 return ret;
3596 }
3597 return ret;
3598 }
3599
3600 static
3601 int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3602 struct lttng_kernel_event_recorder *event_recorder)
3603 {
3604 const char *prev_field_name = NULL;
3605 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3606 int ret = 0;
3607 int i;
3608
3609 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3610 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3611
3612 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3613 if (ret)
3614 return ret;
3615 }
3616 return ret;
3617 }
3618
3619 /*
3620 * Must be called with sessions_mutex held.
3621 * The entire event metadata is printed as a single atomic metadata
3622 * transaction.
3623 */
3624 static
3625 int _lttng_event_metadata_statedump(struct lttng_kernel_session *session,
3626 struct lttng_kernel_channel_buffer *chan,
3627 struct lttng_kernel_event_recorder *event_recorder)
3628 {
3629 int ret = 0;
3630
3631 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3632 return 0;
3633 if (chan->priv->channel_type == METADATA_CHANNEL)
3634 return 0;
3635
3636 lttng_metadata_begin(session);
3637
3638 ret = lttng_metadata_printf(session,
3639 "event {\n"
3640 " name = \"%s\";\n"
3641 " id = %u;\n"
3642 " stream_id = %u;\n",
3643 event_recorder->priv->parent.desc->event_name,
3644 event_recorder->priv->id,
3645 event_recorder->chan->priv->id);
3646 if (ret)
3647 goto end;
3648
3649 ret = lttng_metadata_printf(session,
3650 " fields := struct {\n"
3651 );
3652 if (ret)
3653 goto end;
3654
3655 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3656 if (ret)
3657 goto end;
3658
3659 /*
3660 * LTTng space reservation can only reserve multiples of the
3661 * byte size.
3662 */
3663 ret = lttng_metadata_printf(session,
3664 " };\n"
3665 "};\n\n");
3666 if (ret)
3667 goto end;
3668
3669 event_recorder->priv->metadata_dumped = 1;
3670 end:
3671 lttng_metadata_end(session);
3672 return ret;
3673
3674 }
3675
3676 /*
3677 * Must be called with sessions_mutex held.
3678 * The entire channel metadata is printed as a single atomic metadata
3679 * transaction.
3680 */
3681 static
3682 int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3683 struct lttng_kernel_channel_buffer *chan)
3684 {
3685 int ret = 0;
3686
3687 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3688 return 0;
3689
3690 if (chan->priv->channel_type == METADATA_CHANNEL)
3691 return 0;
3692
3693 lttng_metadata_begin(session);
3694
3695 WARN_ON_ONCE(!chan->priv->header_type);
3696 ret = lttng_metadata_printf(session,
3697 "stream {\n"
3698 " id = %u;\n"
3699 " event.header := %s;\n"
3700 " packet.context := struct packet_context;\n",
3701 chan->priv->id,
3702 chan->priv->header_type == 1 ? "struct event_header_compact" :
3703 "struct event_header_large");
3704 if (ret)
3705 goto end;
3706
3707 if (chan->priv->ctx) {
3708 ret = lttng_metadata_printf(session,
3709 " event.context := struct {\n");
3710 if (ret)
3711 goto end;
3712 }
3713 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3714 if (ret)
3715 goto end;
3716 if (chan->priv->ctx) {
3717 ret = lttng_metadata_printf(session,
3718 " };\n");
3719 if (ret)
3720 goto end;
3721 }
3722
3723 ret = lttng_metadata_printf(session,
3724 "};\n\n");
3725
3726 chan->priv->metadata_dumped = 1;
3727 end:
3728 lttng_metadata_end(session);
3729 return ret;
3730 }
3731
3732 /*
3733 * Must be called with sessions_mutex held.
3734 */
3735 static
3736 int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3737 {
3738 return lttng_metadata_printf(session,
3739 "struct packet_context {\n"
3740 " uint64_clock_monotonic_t timestamp_begin;\n"
3741 " uint64_clock_monotonic_t timestamp_end;\n"
3742 " uint64_t content_size;\n"
3743 " uint64_t packet_size;\n"
3744 " uint64_t packet_seq_num;\n"
3745 " unsigned long events_discarded;\n"
3746 " uint32_t cpu_id;\n"
3747 "};\n\n"
3748 );
3749 }
3750
3751 /*
3752 * Compact header:
3753 * id: range: 0 - 30.
3754 * id 31 is reserved to indicate an extended header.
3755 *
3756 * Large header:
3757 * id: range: 0 - 65534.
3758 * id 65535 is reserved to indicate an extended header.
3759 *
3760 * Must be called with sessions_mutex held.
3761 */
3762 static
3763 int _lttng_event_header_declare(struct lttng_kernel_session *session)
3764 {
3765 return lttng_metadata_printf(session,
3766 "struct event_header_compact {\n"
3767 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3768 " variant <id> {\n"
3769 " struct {\n"
3770 " uint27_clock_monotonic_t timestamp;\n"
3771 " } compact;\n"
3772 " struct {\n"
3773 " uint32_t id;\n"
3774 " uint64_clock_monotonic_t timestamp;\n"
3775 " } extended;\n"
3776 " } v;\n"
3777 "} align(%u);\n"
3778 "\n"
3779 "struct event_header_large {\n"
3780 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3781 " variant <id> {\n"
3782 " struct {\n"
3783 " uint32_clock_monotonic_t timestamp;\n"
3784 " } compact;\n"
3785 " struct {\n"
3786 " uint32_t id;\n"
3787 " uint64_clock_monotonic_t timestamp;\n"
3788 " } extended;\n"
3789 " } v;\n"
3790 "} align(%u);\n\n",
3791 lttng_alignof(uint32_t) * CHAR_BIT,
3792 lttng_alignof(uint16_t) * CHAR_BIT
3793 );
3794 }
3795
3796 /*
3797 * Approximation of NTP time of day to clock monotonic correlation,
3798 * taken at start of trace.
3799 * Yes, this is only an approximation. Yes, we can (and will) do better
3800 * in future versions.
3801 * This function may return a negative offset. It may happen if the
3802 * system sets the REALTIME clock to 0 after boot.
3803 *
3804 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3805 * y2038 compliant.
3806 */
3807 static
3808 int64_t measure_clock_offset(void)
3809 {
3810 uint64_t monotonic_avg, monotonic[2], realtime;
3811 uint64_t tcf = trace_clock_freq();
3812 int64_t offset;
3813 unsigned long flags;
3814 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3815 struct timespec64 rts = { 0, 0 };
3816 #else
3817 struct timespec rts = { 0, 0 };
3818 #endif
3819
3820 /* Disable interrupts to increase correlation precision. */
3821 local_irq_save(flags);
3822 monotonic[0] = trace_clock_read64();
3823 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3824 ktime_get_real_ts64(&rts);
3825 #else
3826 getnstimeofday(&rts);
3827 #endif
3828 monotonic[1] = trace_clock_read64();
3829 local_irq_restore(flags);
3830
3831 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3832 realtime = (uint64_t) rts.tv_sec * tcf;
3833 if (tcf == NSEC_PER_SEC) {
3834 realtime += rts.tv_nsec;
3835 } else {
3836 uint64_t n = rts.tv_nsec * tcf;
3837
3838 do_div(n, NSEC_PER_SEC);
3839 realtime += n;
3840 }
3841 offset = (int64_t) realtime - monotonic_avg;
3842 return offset;
3843 }
3844
3845 static
3846 int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3847 {
3848 int ret = 0;
3849 size_t i;
3850 char cur;
3851
3852 i = 0;
3853 cur = string[i];
3854 while (cur != '\0') {
3855 switch (cur) {
3856 case '\n':
3857 ret = lttng_metadata_printf(session, "%s", "\\n");
3858 break;
3859 case '\\':
3860 case '"':
3861 ret = lttng_metadata_printf(session, "%c", '\\');
3862 if (ret)
3863 goto error;
3864 /* We still print the current char */
3865 lttng_fallthrough;
3866 default:
3867 ret = lttng_metadata_printf(session, "%c", cur);
3868 break;
3869 }
3870
3871 if (ret)
3872 goto error;
3873
3874 cur = string[++i];
3875 }
3876 error:
3877 return ret;
3878 }
3879
3880 static
3881 int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3882 const char *field_value)
3883 {
3884 int ret;
3885
3886 ret = lttng_metadata_printf(session, " %s = \"", field);
3887 if (ret)
3888 goto error;
3889
3890 ret = print_escaped_ctf_string(session, field_value);
3891 if (ret)
3892 goto error;
3893
3894 ret = lttng_metadata_printf(session, "\";\n");
3895
3896 error:
3897 return ret;
3898 }
3899
3900 /*
3901 * Output metadata into this session's metadata buffers.
3902 * Must be called with sessions_mutex held.
3903 */
3904 static
3905 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3906 {
3907 unsigned char *uuid_c = session->priv->uuid.b;
3908 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3909 const char *product_uuid;
3910 struct lttng_kernel_channel_buffer_private *chan_priv;
3911 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3912 int ret = 0;
3913
3914 if (!LTTNG_READ_ONCE(session->active))
3915 return 0;
3916
3917 lttng_metadata_begin(session);
3918
3919 if (session->priv->metadata_dumped)
3920 goto skip_session;
3921
3922 snprintf(uuid_s, sizeof(uuid_s),
3923 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
3924 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
3925 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
3926 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
3927 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
3928
3929 ret = lttng_metadata_printf(session,
3930 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
3931 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
3932 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
3933 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
3934 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
3935 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
3936 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
3937 "\n"
3938 "trace {\n"
3939 " major = %u;\n"
3940 " minor = %u;\n"
3941 " uuid = \"%s\";\n"
3942 " byte_order = %s;\n"
3943 " packet.header := struct {\n"
3944 " uint32_t magic;\n"
3945 " uint8_t uuid[16];\n"
3946 " uint32_t stream_id;\n"
3947 " uint64_t stream_instance_id;\n"
3948 " };\n"
3949 "};\n\n",
3950 lttng_alignof(uint8_t) * CHAR_BIT,
3951 lttng_alignof(uint16_t) * CHAR_BIT,
3952 lttng_alignof(uint32_t) * CHAR_BIT,
3953 lttng_alignof(uint64_t) * CHAR_BIT,
3954 sizeof(unsigned long) * CHAR_BIT,
3955 lttng_alignof(unsigned long) * CHAR_BIT,
3956 CTF_SPEC_MAJOR,
3957 CTF_SPEC_MINOR,
3958 uuid_s,
3959 #if __BYTE_ORDER == __BIG_ENDIAN
3960 "be"
3961 #else
3962 "le"
3963 #endif
3964 );
3965 if (ret)
3966 goto end;
3967
3968 ret = lttng_metadata_printf(session,
3969 "env {\n"
3970 " hostname = \"%s\";\n"
3971 " domain = \"kernel\";\n"
3972 " sysname = \"%s\";\n"
3973 " kernel_release = \"%s\";\n"
3974 " kernel_version = \"%s\";\n"
3975 " tracer_name = \"lttng-modules\";\n"
3976 " tracer_major = %d;\n"
3977 " tracer_minor = %d;\n"
3978 " tracer_patchlevel = %d;\n"
3979 " trace_buffering_scheme = \"global\";\n",
3980 current->nsproxy->uts_ns->name.nodename,
3981 utsname()->sysname,
3982 utsname()->release,
3983 utsname()->version,
3984 LTTNG_MODULES_MAJOR_VERSION,
3985 LTTNG_MODULES_MINOR_VERSION,
3986 LTTNG_MODULES_PATCHLEVEL_VERSION
3987 );
3988 if (ret)
3989 goto end;
3990
3991 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
3992 if (ret)
3993 goto end;
3994 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
3995 session->priv->creation_time);
3996 if (ret)
3997 goto end;
3998
3999 /* Add the product UUID to the 'env' section */
4000 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
4001 if (product_uuid) {
4002 ret = lttng_metadata_printf(session,
4003 " product_uuid = \"%s\";\n",
4004 product_uuid
4005 );
4006 if (ret)
4007 goto end;
4008 }
4009
4010 /* Close the 'env' section */
4011 ret = lttng_metadata_printf(session, "};\n\n");
4012 if (ret)
4013 goto end;
4014
4015 ret = lttng_metadata_printf(session,
4016 "clock {\n"
4017 " name = \"%s\";\n",
4018 trace_clock_name()
4019 );
4020 if (ret)
4021 goto end;
4022
4023 if (!trace_clock_uuid(clock_uuid_s)) {
4024 ret = lttng_metadata_printf(session,
4025 " uuid = \"%s\";\n",
4026 clock_uuid_s
4027 );
4028 if (ret)
4029 goto end;
4030 }
4031
4032 ret = lttng_metadata_printf(session,
4033 " description = \"%s\";\n"
4034 " freq = %llu; /* Frequency, in Hz */\n"
4035 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
4036 " offset = %lld;\n"
4037 "};\n\n",
4038 trace_clock_description(),
4039 (unsigned long long) trace_clock_freq(),
4040 (long long) measure_clock_offset()
4041 );
4042 if (ret)
4043 goto end;
4044
4045 ret = lttng_metadata_printf(session,
4046 "typealias integer {\n"
4047 " size = 27; align = 1; signed = false;\n"
4048 " map = clock.%s.value;\n"
4049 "} := uint27_clock_monotonic_t;\n"
4050 "\n"
4051 "typealias integer {\n"
4052 " size = 32; align = %u; signed = false;\n"
4053 " map = clock.%s.value;\n"
4054 "} := uint32_clock_monotonic_t;\n"
4055 "\n"
4056 "typealias integer {\n"
4057 " size = 64; align = %u; signed = false;\n"
4058 " map = clock.%s.value;\n"
4059 "} := uint64_clock_monotonic_t;\n\n",
4060 trace_clock_name(),
4061 lttng_alignof(uint32_t) * CHAR_BIT,
4062 trace_clock_name(),
4063 lttng_alignof(uint64_t) * CHAR_BIT,
4064 trace_clock_name()
4065 );
4066 if (ret)
4067 goto end;
4068
4069 ret = _lttng_stream_packet_context_declare(session);
4070 if (ret)
4071 goto end;
4072
4073 ret = _lttng_event_header_declare(session);
4074 if (ret)
4075 goto end;
4076
4077 skip_session:
4078 list_for_each_entry(chan_priv, &session->priv->chan, node) {
4079 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
4080 if (ret)
4081 goto end;
4082 }
4083
4084 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
4085 ret = _lttng_event_metadata_statedump(session, event_recorder_priv->pub->chan,
4086 event_recorder_priv->pub);
4087 if (ret)
4088 goto end;
4089 }
4090 session->priv->metadata_dumped = 1;
4091 end:
4092 lttng_metadata_end(session);
4093 return ret;
4094 }
4095
4096 /**
4097 * lttng_transport_register - LTT transport registration
4098 * @transport: transport structure
4099 *
4100 * Registers a transport which can be used as output to extract the data out of
4101 * LTTng. The module calling this registration function must ensure that no
4102 * trap-inducing code will be executed by the transport functions. E.g.
4103 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
4104 * is made visible to the transport function. This registration acts as a
4105 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
4106 * after its registration must it synchronize the TLBs.
4107 */
4108 void lttng_transport_register(struct lttng_transport *transport)
4109 {
4110 /*
4111 * Make sure no page fault can be triggered by the module about to be
4112 * registered. We deal with this here so we don't have to call
4113 * vmalloc_sync_mappings() in each module's init.
4114 */
4115 wrapper_vmalloc_sync_mappings();
4116
4117 mutex_lock(&sessions_mutex);
4118 list_add_tail(&transport->node, &lttng_transport_list);
4119 mutex_unlock(&sessions_mutex);
4120 }
4121 EXPORT_SYMBOL_GPL(lttng_transport_register);
4122
4123 /**
4124 * lttng_transport_unregister - LTT transport unregistration
4125 * @transport: transport structure
4126 */
4127 void lttng_transport_unregister(struct lttng_transport *transport)
4128 {
4129 mutex_lock(&sessions_mutex);
4130 list_del(&transport->node);
4131 mutex_unlock(&sessions_mutex);
4132 }
4133 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4134
4135 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4136 {
4137 /*
4138 * Make sure no page fault can be triggered by the module about to be
4139 * registered. We deal with this here so we don't have to call
4140 * vmalloc_sync_mappings() in each module's init.
4141 */
4142 wrapper_vmalloc_sync_mappings();
4143
4144 mutex_lock(&sessions_mutex);
4145 list_add_tail(&transport->node, &lttng_counter_transport_list);
4146 mutex_unlock(&sessions_mutex);
4147 }
4148 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4149
4150 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4151 {
4152 mutex_lock(&sessions_mutex);
4153 list_del(&transport->node);
4154 mutex_unlock(&sessions_mutex);
4155 }
4156 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4157
4158 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4159
4160 enum cpuhp_state lttng_hp_prepare;
4161 enum cpuhp_state lttng_hp_online;
4162
4163 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4164 {
4165 struct lttng_cpuhp_node *lttng_node;
4166
4167 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4168 switch (lttng_node->component) {
4169 case LTTNG_RING_BUFFER_FRONTEND:
4170 return 0;
4171 case LTTNG_RING_BUFFER_BACKEND:
4172 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4173 case LTTNG_RING_BUFFER_ITER:
4174 return 0;
4175 case LTTNG_CONTEXT_PERF_COUNTERS:
4176 return 0;
4177 default:
4178 return -EINVAL;
4179 }
4180 }
4181
4182 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4183 {
4184 struct lttng_cpuhp_node *lttng_node;
4185
4186 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4187 switch (lttng_node->component) {
4188 case LTTNG_RING_BUFFER_FRONTEND:
4189 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4190 case LTTNG_RING_BUFFER_BACKEND:
4191 return 0;
4192 case LTTNG_RING_BUFFER_ITER:
4193 return 0;
4194 case LTTNG_CONTEXT_PERF_COUNTERS:
4195 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4196 default:
4197 return -EINVAL;
4198 }
4199 }
4200
4201 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4202 {
4203 struct lttng_cpuhp_node *lttng_node;
4204
4205 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4206 switch (lttng_node->component) {
4207 case LTTNG_RING_BUFFER_FRONTEND:
4208 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4209 case LTTNG_RING_BUFFER_BACKEND:
4210 return 0;
4211 case LTTNG_RING_BUFFER_ITER:
4212 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4213 case LTTNG_CONTEXT_PERF_COUNTERS:
4214 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4215 default:
4216 return -EINVAL;
4217 }
4218 }
4219
4220 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4221 {
4222 struct lttng_cpuhp_node *lttng_node;
4223
4224 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4225 switch (lttng_node->component) {
4226 case LTTNG_RING_BUFFER_FRONTEND:
4227 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4228 case LTTNG_RING_BUFFER_BACKEND:
4229 return 0;
4230 case LTTNG_RING_BUFFER_ITER:
4231 return 0;
4232 case LTTNG_CONTEXT_PERF_COUNTERS:
4233 return 0;
4234 default:
4235 return -EINVAL;
4236 }
4237 }
4238
4239 static int __init lttng_init_cpu_hotplug(void)
4240 {
4241 int ret;
4242
4243 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4244 lttng_hotplug_prepare,
4245 lttng_hotplug_dead);
4246 if (ret < 0) {
4247 return ret;
4248 }
4249 lttng_hp_prepare = ret;
4250 lttng_rb_set_hp_prepare(ret);
4251
4252 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4253 lttng_hotplug_online,
4254 lttng_hotplug_offline);
4255 if (ret < 0) {
4256 cpuhp_remove_multi_state(lttng_hp_prepare);
4257 lttng_hp_prepare = 0;
4258 return ret;
4259 }
4260 lttng_hp_online = ret;
4261 lttng_rb_set_hp_online(ret);
4262
4263 return 0;
4264 }
4265
4266 static void __exit lttng_exit_cpu_hotplug(void)
4267 {
4268 lttng_rb_set_hp_online(0);
4269 cpuhp_remove_multi_state(lttng_hp_online);
4270 lttng_rb_set_hp_prepare(0);
4271 cpuhp_remove_multi_state(lttng_hp_prepare);
4272 }
4273
4274 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4275 static int lttng_init_cpu_hotplug(void)
4276 {
4277 return 0;
4278 }
4279 static void lttng_exit_cpu_hotplug(void)
4280 {
4281 }
4282 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4283
4284 static int __init lttng_events_init(void)
4285 {
4286 int ret;
4287
4288 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4289 if (ret)
4290 return ret;
4291 ret = wrapper_get_pfnblock_flags_mask_init();
4292 if (ret)
4293 return ret;
4294 ret = wrapper_get_pageblock_flags_mask_init();
4295 if (ret)
4296 return ret;
4297 ret = lttng_probes_init();
4298 if (ret)
4299 return ret;
4300 ret = lttng_context_init();
4301 if (ret)
4302 return ret;
4303 ret = lttng_tracepoint_init();
4304 if (ret)
4305 goto error_tp;
4306 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4307 if (!event_recorder_cache) {
4308 ret = -ENOMEM;
4309 goto error_kmem_event_recorder;
4310 }
4311 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4312 if (!event_recorder_private_cache) {
4313 ret = -ENOMEM;
4314 goto error_kmem_event_recorder_private;
4315 }
4316 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4317 if (!event_notifier_cache) {
4318 ret = -ENOMEM;
4319 goto error_kmem_event_notifier;
4320 }
4321 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4322 if (!event_notifier_private_cache) {
4323 ret = -ENOMEM;
4324 goto error_kmem_event_notifier_private;
4325 }
4326 ret = lttng_abi_init();
4327 if (ret)
4328 goto error_abi;
4329 ret = lttng_logger_init();
4330 if (ret)
4331 goto error_logger;
4332 ret = lttng_init_cpu_hotplug();
4333 if (ret)
4334 goto error_hotplug;
4335 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4336 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4337 __stringify(LTTNG_MODULES_MINOR_VERSION),
4338 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4339 LTTNG_MODULES_EXTRAVERSION,
4340 LTTNG_VERSION_NAME,
4341 #ifdef LTTNG_EXTRA_VERSION_GIT
4342 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4343 #else
4344 "",
4345 #endif
4346 #ifdef LTTNG_EXTRA_VERSION_NAME
4347 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4348 #else
4349 "");
4350 #endif
4351 #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
4352 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
4353 #endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
4354 return 0;
4355
4356 error_hotplug:
4357 lttng_logger_exit();
4358 error_logger:
4359 lttng_abi_exit();
4360 error_abi:
4361 kmem_cache_destroy(event_notifier_private_cache);
4362 error_kmem_event_notifier_private:
4363 kmem_cache_destroy(event_notifier_cache);
4364 error_kmem_event_notifier:
4365 kmem_cache_destroy(event_recorder_private_cache);
4366 error_kmem_event_recorder_private:
4367 kmem_cache_destroy(event_recorder_cache);
4368 error_kmem_event_recorder:
4369 lttng_tracepoint_exit();
4370 error_tp:
4371 lttng_context_exit();
4372 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4373 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4374 __stringify(LTTNG_MODULES_MINOR_VERSION),
4375 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4376 LTTNG_MODULES_EXTRAVERSION,
4377 LTTNG_VERSION_NAME,
4378 #ifdef LTTNG_EXTRA_VERSION_GIT
4379 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4380 #else
4381 "",
4382 #endif
4383 #ifdef LTTNG_EXTRA_VERSION_NAME
4384 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4385 #else
4386 "");
4387 #endif
4388 return ret;
4389 }
4390
4391 module_init(lttng_events_init);
4392
4393 static void __exit lttng_events_exit(void)
4394 {
4395 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4396
4397 lttng_exit_cpu_hotplug();
4398 lttng_logger_exit();
4399 lttng_abi_exit();
4400 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4401 lttng_session_destroy(session_priv->pub);
4402 kmem_cache_destroy(event_recorder_cache);
4403 kmem_cache_destroy(event_recorder_private_cache);
4404 kmem_cache_destroy(event_notifier_cache);
4405 kmem_cache_destroy(event_notifier_private_cache);
4406 lttng_tracepoint_exit();
4407 lttng_context_exit();
4408 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4409 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4410 __stringify(LTTNG_MODULES_MINOR_VERSION),
4411 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4412 LTTNG_MODULES_EXTRAVERSION,
4413 LTTNG_VERSION_NAME,
4414 #ifdef LTTNG_EXTRA_VERSION_GIT
4415 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4416 #else
4417 "",
4418 #endif
4419 #ifdef LTTNG_EXTRA_VERSION_NAME
4420 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4421 #else
4422 "");
4423 #endif
4424 }
4425
4426 module_exit(lttng_events_exit);
4427
4428 #include <generated/patches.h>
4429 #ifdef LTTNG_EXTRA_VERSION_GIT
4430 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4431 #endif
4432 #ifdef LTTNG_EXTRA_VERSION_NAME
4433 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4434 #endif
4435 MODULE_LICENSE("GPL and additional rights");
4436 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4437 MODULE_DESCRIPTION("LTTng tracer");
4438 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4439 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4440 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4441 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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