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