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981ee30c326cb65be35ff7b6d107d600e09633a4
[lttng-modules.git] / src / lttng-events.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
2 *
3 * lttng-events.c
4 *
5 * Holds LTTng per-session event registry.
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10 /*
11 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
12 * overrides a function with a define.
13 */
14 #include "wrapper/page_alloc.h"
15
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/jiffies.h>
21 #include <linux/utsname.h>
22 #include <linux/err.h>
23 #include <linux/seq_file.h>
24 #include <linux/file.h>
25 #include <linux/anon_inodes.h>
26 #include <wrapper/file.h>
27 #include <linux/uaccess.h>
28 #include <linux/vmalloc.h>
29 #include <linux/dmi.h>
30
31 #include <wrapper/compiler_attributes.h>
32 #include <wrapper/uuid.h>
33 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
34 #include <wrapper/random.h>
35 #include <wrapper/tracepoint.h>
36 #include <wrapper/list.h>
37 #include <wrapper/types.h>
38 #include <lttng/kernel-version.h>
39 #include <lttng/events.h>
40 #include <lttng/events-internal.h>
41 #include <lttng/lttng-bytecode.h>
42 #include <lttng/tracer.h>
43 #include <lttng/event-notifier-notification.h>
44 #include <lttng/abi-old.h>
45 #include <lttng/endian.h>
46 #include <lttng/string-utils.h>
47 #include <lttng/utils.h>
48 #include <ringbuffer/backend.h>
49 #include <ringbuffer/frontend.h>
50 #include <wrapper/time.h>
51
52 #define METADATA_CACHE_DEFAULT_SIZE 4096
53
54 static LIST_HEAD(sessions);
55 static LIST_HEAD(event_notifier_groups);
56 static LIST_HEAD(lttng_transport_list);
57 static LIST_HEAD(lttng_counter_transport_list);
58 /*
59 * Protect the sessions and metadata caches.
60 */
61 static DEFINE_MUTEX(sessions_mutex);
62 static struct kmem_cache *event_recorder_cache;
63 static struct kmem_cache *event_recorder_private_cache;
64 static struct kmem_cache *event_notifier_cache;
65 static struct kmem_cache *event_notifier_private_cache;
66
67 static void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session);
68 static void lttng_session_sync_event_enablers(struct lttng_kernel_session *session);
69 static void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group);
70 static void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler);
71
72 static void _lttng_event_destroy(struct lttng_kernel_event_common *event);
73 static void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan);
74 static int _lttng_event_unregister(struct lttng_kernel_event_common *event);
75 static
76 int _lttng_event_recorder_metadata_statedump(struct lttng_kernel_event_common *event);
77 static
78 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session);
79 static
80 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
81 static
82 int _lttng_type_statedump(struct lttng_kernel_session *session,
83 const struct lttng_kernel_type_common *type,
84 enum lttng_kernel_string_encoding parent_encoding,
85 size_t nesting);
86 static
87 int _lttng_field_statedump(struct lttng_kernel_session *session,
88 const struct lttng_kernel_event_field *field,
89 size_t nesting, const char **prev_field_name_p);
90
91 void synchronize_trace(void)
92 {
93 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,1,0) || \
94 LTTNG_RHEL_KERNEL_RANGE(4,18,0,193,0,0, 4,19,0,0,0,0))
95 synchronize_rcu();
96 #else
97 synchronize_sched();
98 #endif
99
100 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
101 #ifdef CONFIG_PREEMPT_RT_FULL
102 synchronize_rcu();
103 #endif
104 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
105 #ifdef CONFIG_PREEMPT_RT
106 synchronize_rcu();
107 #endif
108 #endif /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0)) */
109 }
110
111 void lttng_lock_sessions(void)
112 {
113 mutex_lock(&sessions_mutex);
114 }
115
116 void lttng_unlock_sessions(void)
117 {
118 mutex_unlock(&sessions_mutex);
119 }
120
121 static struct lttng_transport *lttng_transport_find(const char *name)
122 {
123 struct lttng_transport *transport;
124
125 list_for_each_entry(transport, &lttng_transport_list, node) {
126 if (!strcmp(transport->name, name))
127 return transport;
128 }
129 return NULL;
130 }
131
132 /*
133 * Called with sessions lock held.
134 */
135 int lttng_session_active(void)
136 {
137 struct lttng_kernel_session_private *iter;
138
139 list_for_each_entry(iter, &sessions, list) {
140 if (iter->pub->active)
141 return 1;
142 }
143 return 0;
144 }
145
146 struct lttng_kernel_session *lttng_session_create(void)
147 {
148 struct lttng_kernel_session *session;
149 struct lttng_kernel_session_private *session_priv;
150 struct lttng_metadata_cache *metadata_cache;
151 int i;
152
153 mutex_lock(&sessions_mutex);
154 session = lttng_kvzalloc(sizeof(*session), GFP_KERNEL);
155 if (!session)
156 goto err;
157 session_priv = lttng_kvzalloc(sizeof(*session_priv), GFP_KERNEL);
158 if (!session_priv)
159 goto err_free_session;
160 session->priv = session_priv;
161 session_priv->pub = session;
162
163 INIT_LIST_HEAD(&session_priv->chan);
164 INIT_LIST_HEAD(&session_priv->events);
165 lttng_guid_gen(&session_priv->uuid);
166
167 metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
168 GFP_KERNEL);
169 if (!metadata_cache)
170 goto err_free_session_private;
171 metadata_cache->data = vzalloc(METADATA_CACHE_DEFAULT_SIZE);
172 if (!metadata_cache->data)
173 goto err_free_cache;
174 metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
175 kref_init(&metadata_cache->refcount);
176 mutex_init(&metadata_cache->lock);
177 session_priv->metadata_cache = metadata_cache;
178 INIT_LIST_HEAD(&metadata_cache->metadata_stream);
179 memcpy(&metadata_cache->uuid, &session_priv->uuid,
180 sizeof(metadata_cache->uuid));
181 INIT_LIST_HEAD(&session_priv->enablers_head);
182 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
183 INIT_HLIST_HEAD(&session_priv->events_ht.table[i]);
184 list_add(&session_priv->list, &sessions);
185
186 if (lttng_id_tracker_init(&session->pid_tracker, session, TRACKER_PID))
187 goto tracker_alloc_error;
188 if (lttng_id_tracker_init(&session->vpid_tracker, session, TRACKER_VPID))
189 goto tracker_alloc_error;
190 if (lttng_id_tracker_init(&session->uid_tracker, session, TRACKER_UID))
191 goto tracker_alloc_error;
192 if (lttng_id_tracker_init(&session->vuid_tracker, session, TRACKER_VUID))
193 goto tracker_alloc_error;
194 if (lttng_id_tracker_init(&session->gid_tracker, session, TRACKER_GID))
195 goto tracker_alloc_error;
196 if (lttng_id_tracker_init(&session->vgid_tracker, session, TRACKER_VGID))
197 goto tracker_alloc_error;
198
199 mutex_unlock(&sessions_mutex);
200
201 return session;
202
203 tracker_alloc_error:
204 lttng_id_tracker_fini(&session->pid_tracker);
205 lttng_id_tracker_fini(&session->vpid_tracker);
206 lttng_id_tracker_fini(&session->uid_tracker);
207 lttng_id_tracker_fini(&session->vuid_tracker);
208 lttng_id_tracker_fini(&session->gid_tracker);
209 lttng_id_tracker_fini(&session->vgid_tracker);
210 err_free_cache:
211 kfree(metadata_cache);
212 err_free_session_private:
213 lttng_kvfree(session_priv);
214 err_free_session:
215 lttng_kvfree(session);
216 err:
217 mutex_unlock(&sessions_mutex);
218 return NULL;
219 }
220
221 static
222 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
223 {
224 struct lttng_counter_transport *transport;
225
226 list_for_each_entry(transport, &lttng_counter_transport_list, node) {
227 if (!strcmp(transport->name, name))
228 return transport;
229 }
230 return NULL;
231 }
232
233 struct lttng_counter *lttng_kernel_counter_create(
234 const char *counter_transport_name,
235 size_t number_dimensions, const size_t *dimensions_sizes)
236 {
237 struct lttng_counter *counter = NULL;
238 struct lttng_counter_transport *counter_transport = NULL;
239
240 counter_transport = lttng_counter_transport_find(counter_transport_name);
241 if (!counter_transport) {
242 printk(KERN_WARNING "LTTng: counter transport %s not found.\n",
243 counter_transport_name);
244 goto notransport;
245 }
246 if (!try_module_get(counter_transport->owner)) {
247 printk(KERN_WARNING "LTTng: Can't lock counter transport module.\n");
248 goto notransport;
249 }
250
251 counter = lttng_kvzalloc(sizeof(struct lttng_counter), GFP_KERNEL);
252 if (!counter)
253 goto nomem;
254
255 /* Create event notifier error counter. */
256 counter->ops = &counter_transport->ops;
257 counter->transport = counter_transport;
258
259 counter->counter = counter->ops->counter_create(
260 number_dimensions, dimensions_sizes, 0);
261 if (!counter->counter) {
262 goto create_error;
263 }
264
265 return counter;
266
267 create_error:
268 lttng_kvfree(counter);
269 nomem:
270 if (counter_transport)
271 module_put(counter_transport->owner);
272 notransport:
273 return NULL;
274 }
275
276 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
277 {
278 struct lttng_transport *transport = NULL;
279 struct lttng_event_notifier_group *event_notifier_group;
280 const char *transport_name = "relay-event-notifier";
281 size_t subbuf_size = 4096; //TODO
282 size_t num_subbuf = 16; //TODO
283 unsigned int switch_timer_interval = 0;
284 unsigned int read_timer_interval = 0;
285 int i;
286
287 mutex_lock(&sessions_mutex);
288
289 transport = lttng_transport_find(transport_name);
290 if (!transport) {
291 printk(KERN_WARNING "LTTng: transport %s not found\n",
292 transport_name);
293 goto notransport;
294 }
295 if (!try_module_get(transport->owner)) {
296 printk(KERN_WARNING "LTTng: Can't lock transport %s module.\n",
297 transport_name);
298 goto notransport;
299 }
300
301 event_notifier_group = lttng_kvzalloc(sizeof(struct lttng_event_notifier_group),
302 GFP_KERNEL);
303 if (!event_notifier_group)
304 goto nomem;
305
306 /*
307 * Initialize the ring buffer used to store event notifier
308 * notifications.
309 */
310 event_notifier_group->ops = &transport->ops;
311 event_notifier_group->chan = transport->ops.priv->channel_create(
312 transport_name, event_notifier_group, NULL,
313 subbuf_size, num_subbuf, switch_timer_interval,
314 read_timer_interval);
315 if (!event_notifier_group->chan)
316 goto create_error;
317
318 event_notifier_group->transport = transport;
319
320 INIT_LIST_HEAD(&event_notifier_group->enablers_head);
321 INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
322 for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
323 INIT_HLIST_HEAD(&event_notifier_group->events_ht.table[i]);
324
325 list_add(&event_notifier_group->node, &event_notifier_groups);
326
327 mutex_unlock(&sessions_mutex);
328
329 return event_notifier_group;
330
331 create_error:
332 lttng_kvfree(event_notifier_group);
333 nomem:
334 if (transport)
335 module_put(transport->owner);
336 notransport:
337 mutex_unlock(&sessions_mutex);
338 return NULL;
339 }
340
341 void metadata_cache_destroy(struct kref *kref)
342 {
343 struct lttng_metadata_cache *cache =
344 container_of(kref, struct lttng_metadata_cache, refcount);
345 vfree(cache->data);
346 kfree(cache);
347 }
348
349 void lttng_session_destroy(struct lttng_kernel_session *session)
350 {
351 struct lttng_kernel_channel_buffer_private *chan_priv, *tmpchan_priv;
352 struct lttng_kernel_event_recorder_private *event_recorder_priv, *tmpevent_recorder_priv;
353 struct lttng_metadata_stream *metadata_stream;
354 struct lttng_event_enabler_common *event_enabler, *tmp_event_enabler;
355 int ret;
356
357 mutex_lock(&sessions_mutex);
358 WRITE_ONCE(session->active, 0);
359 list_for_each_entry(chan_priv, &session->priv->chan, node) {
360 ret = lttng_syscalls_unregister_syscall_table(&chan_priv->parent.syscall_table);
361 WARN_ON(ret);
362 }
363 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
364 ret = _lttng_event_unregister(&event_recorder_priv->pub->parent);
365 WARN_ON(ret);
366 }
367 synchronize_trace(); /* Wait for in-flight events to complete */
368 list_for_each_entry(chan_priv, &session->priv->chan, node) {
369 ret = lttng_syscalls_destroy_syscall_table(&chan_priv->parent.syscall_table);
370 WARN_ON(ret);
371 }
372 list_for_each_entry_safe(event_enabler, tmp_event_enabler, &session->priv->enablers_head, node)
373 lttng_event_enabler_destroy(event_enabler);
374 list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv, &session->priv->events, parent.node)
375 _lttng_event_destroy(&event_recorder_priv->pub->parent);
376 list_for_each_entry_safe(chan_priv, tmpchan_priv, &session->priv->chan, node) {
377 BUG_ON(chan_priv->channel_type == METADATA_CHANNEL);
378 _lttng_channel_destroy(chan_priv->pub);
379 }
380 mutex_lock(&session->priv->metadata_cache->lock);
381 list_for_each_entry(metadata_stream, &session->priv->metadata_cache->metadata_stream, list)
382 _lttng_metadata_channel_hangup(metadata_stream);
383 mutex_unlock(&session->priv->metadata_cache->lock);
384 lttng_id_tracker_fini(&session->pid_tracker);
385 lttng_id_tracker_fini(&session->vpid_tracker);
386 lttng_id_tracker_fini(&session->uid_tracker);
387 lttng_id_tracker_fini(&session->vuid_tracker);
388 lttng_id_tracker_fini(&session->gid_tracker);
389 lttng_id_tracker_fini(&session->vgid_tracker);
390 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
391 list_del(&session->priv->list);
392 mutex_unlock(&sessions_mutex);
393 lttng_kvfree(session->priv);
394 lttng_kvfree(session);
395 }
396
397 void lttng_event_notifier_group_destroy(
398 struct lttng_event_notifier_group *event_notifier_group)
399 {
400 struct lttng_event_enabler_common *event_enabler, *tmp_event_enabler;
401 struct lttng_kernel_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
402 int ret;
403
404 if (!event_notifier_group)
405 return;
406
407 mutex_lock(&sessions_mutex);
408
409 ret = lttng_syscalls_unregister_syscall_table(&event_notifier_group->syscall_table);
410 WARN_ON(ret);
411
412 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
413 &event_notifier_group->event_notifiers_head, parent.node) {
414 ret = _lttng_event_unregister(&event_notifier_priv->pub->parent);
415 WARN_ON(ret);
416 }
417
418 /* Wait for in-flight event notifier to complete */
419 synchronize_trace();
420
421 irq_work_sync(&event_notifier_group->wakeup_pending);
422
423 ret = lttng_syscalls_destroy_syscall_table(&event_notifier_group->syscall_table);
424 WARN_ON(ret);
425
426 list_for_each_entry_safe(event_enabler, tmp_event_enabler,
427 &event_notifier_group->enablers_head, node)
428 lttng_event_enabler_destroy(event_enabler);
429
430 list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
431 &event_notifier_group->event_notifiers_head, parent.node)
432 _lttng_event_destroy(&event_notifier_priv->pub->parent);
433
434 if (event_notifier_group->error_counter) {
435 struct lttng_counter *error_counter = event_notifier_group->error_counter;
436
437 error_counter->ops->counter_destroy(error_counter->counter);
438 module_put(error_counter->transport->owner);
439 lttng_kvfree(error_counter);
440 event_notifier_group->error_counter = NULL;
441 }
442
443 event_notifier_group->ops->priv->channel_destroy(event_notifier_group->chan);
444 module_put(event_notifier_group->transport->owner);
445 list_del(&event_notifier_group->node);
446
447 mutex_unlock(&sessions_mutex);
448 lttng_kvfree(event_notifier_group);
449 }
450
451 int lttng_session_statedump(struct lttng_kernel_session *session)
452 {
453 int ret;
454
455 mutex_lock(&sessions_mutex);
456 ret = lttng_statedump_start(session);
457 mutex_unlock(&sessions_mutex);
458 return ret;
459 }
460
461 int lttng_session_enable(struct lttng_kernel_session *session)
462 {
463 int ret = 0;
464 struct lttng_kernel_channel_buffer_private *chan_priv;
465
466 mutex_lock(&sessions_mutex);
467 if (session->active) {
468 ret = -EBUSY;
469 goto end;
470 }
471
472 /* Set transient enabler state to "enabled" */
473 session->priv->tstate = 1;
474
475 /* We need to sync enablers with session before activation. */
476 lttng_session_sync_event_enablers(session);
477
478 /*
479 * Snapshot the number of events per channel to know the type of header
480 * we need to use.
481 */
482 list_for_each_entry(chan_priv, &session->priv->chan, node) {
483 if (chan_priv->header_type)
484 continue; /* don't change it if session stop/restart */
485 if (chan_priv->free_event_id < 31)
486 chan_priv->header_type = 1; /* compact */
487 else
488 chan_priv->header_type = 2; /* large */
489 }
490
491 /* Clear each stream's quiescent state. */
492 list_for_each_entry(chan_priv, &session->priv->chan, node) {
493 if (chan_priv->channel_type != METADATA_CHANNEL)
494 lib_ring_buffer_clear_quiescent_channel(chan_priv->rb_chan);
495 }
496
497 WRITE_ONCE(session->active, 1);
498 WRITE_ONCE(session->priv->been_active, 1);
499 ret = _lttng_session_metadata_statedump(session);
500 if (ret) {
501 WRITE_ONCE(session->active, 0);
502 goto end;
503 }
504 ret = lttng_statedump_start(session);
505 if (ret)
506 WRITE_ONCE(session->active, 0);
507 end:
508 mutex_unlock(&sessions_mutex);
509 return ret;
510 }
511
512 int lttng_session_disable(struct lttng_kernel_session *session)
513 {
514 int ret = 0;
515 struct lttng_kernel_channel_buffer_private *chan_priv;
516
517 mutex_lock(&sessions_mutex);
518 if (!session->active) {
519 ret = -EBUSY;
520 goto end;
521 }
522 WRITE_ONCE(session->active, 0);
523
524 /* Set transient enabler state to "disabled" */
525 session->priv->tstate = 0;
526 lttng_session_sync_event_enablers(session);
527
528 /* Set each stream's quiescent state. */
529 list_for_each_entry(chan_priv, &session->priv->chan, node) {
530 if (chan_priv->channel_type != METADATA_CHANNEL)
531 lib_ring_buffer_set_quiescent_channel(chan_priv->rb_chan);
532 }
533 end:
534 mutex_unlock(&sessions_mutex);
535 return ret;
536 }
537
538 int lttng_session_metadata_regenerate(struct lttng_kernel_session *session)
539 {
540 int ret = 0;
541 struct lttng_kernel_channel_buffer_private *chan_priv;
542 struct lttng_kernel_event_recorder_private *event_recorder_priv;
543 struct lttng_metadata_cache *cache = session->priv->metadata_cache;
544 struct lttng_metadata_stream *stream;
545
546 mutex_lock(&sessions_mutex);
547 if (!session->active) {
548 ret = -EBUSY;
549 goto end;
550 }
551
552 mutex_lock(&cache->lock);
553 memset(cache->data, 0, cache->cache_alloc);
554 cache->metadata_written = 0;
555 cache->version++;
556 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list) {
557 stream->metadata_out = 0;
558 stream->metadata_in = 0;
559 }
560 mutex_unlock(&cache->lock);
561
562 session->priv->metadata_dumped = 0;
563 list_for_each_entry(chan_priv, &session->priv->chan, node) {
564 chan_priv->metadata_dumped = 0;
565 }
566
567 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
568 event_recorder_priv->metadata_dumped = 0;
569 }
570
571 ret = _lttng_session_metadata_statedump(session);
572
573 end:
574 mutex_unlock(&sessions_mutex);
575 return ret;
576 }
577
578 static
579 bool is_channel_buffer_metadata(struct lttng_kernel_channel_common *channel)
580 {
581 struct lttng_kernel_channel_buffer *chan_buf;
582
583 if (channel->type != LTTNG_KERNEL_CHANNEL_TYPE_BUFFER)
584 return false;
585 chan_buf = container_of(channel, struct lttng_kernel_channel_buffer, parent);
586 if (chan_buf->priv->channel_type == METADATA_CHANNEL)
587 return true;
588 return false;
589 }
590
591 int lttng_channel_enable(struct lttng_kernel_channel_common *channel)
592 {
593 int ret = 0;
594
595 mutex_lock(&sessions_mutex);
596 if (is_channel_buffer_metadata(channel)) {
597 ret = -EPERM;
598 goto end;
599 }
600 if (channel->enabled) {
601 ret = -EEXIST;
602 goto end;
603 }
604 /* Set transient enabler state to "enabled" */
605 channel->priv->tstate = 1;
606 lttng_session_sync_event_enablers(channel->session);
607 /* Set atomically the state to "enabled" */
608 WRITE_ONCE(channel->enabled, 1);
609 end:
610 mutex_unlock(&sessions_mutex);
611 return ret;
612 }
613
614 int lttng_channel_disable(struct lttng_kernel_channel_common *channel)
615 {
616 int ret = 0;
617
618 mutex_lock(&sessions_mutex);
619 if (is_channel_buffer_metadata(channel)) {
620 ret = -EPERM;
621 goto end;
622 }
623 if (!channel->enabled) {
624 ret = -EEXIST;
625 goto end;
626 }
627 /* Set atomically the state to "disabled" */
628 WRITE_ONCE(channel->enabled, 0);
629 /* Set transient enabler state to "enabled" */
630 channel->priv->tstate = 0;
631 lttng_session_sync_event_enablers(channel->session);
632 end:
633 mutex_unlock(&sessions_mutex);
634 return ret;
635 }
636
637 int lttng_event_enable(struct lttng_kernel_event_common *event)
638 {
639 int ret = 0;
640
641 mutex_lock(&sessions_mutex);
642 switch (event->type) {
643 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
644 {
645 struct lttng_kernel_event_recorder *event_recorder =
646 container_of(event, struct lttng_kernel_event_recorder, parent);
647
648 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
649 ret = -EPERM;
650 goto end;
651 }
652 break;
653 }
654 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
655 switch (event->priv->instrumentation) {
656 case LTTNG_KERNEL_ABI_KRETPROBE:
657 ret = -EINVAL;
658 goto end;
659 default:
660 break;
661 }
662 break;
663 default:
664 break;
665 }
666
667 if (event->enabled) {
668 ret = -EEXIST;
669 goto end;
670 }
671 switch (event->priv->instrumentation) {
672 case LTTNG_KERNEL_ABI_TRACEPOINT:
673 lttng_fallthrough;
674 case LTTNG_KERNEL_ABI_SYSCALL:
675 ret = -EINVAL;
676 break;
677
678 case LTTNG_KERNEL_ABI_KPROBE:
679 lttng_fallthrough;
680 case LTTNG_KERNEL_ABI_UPROBE:
681 WRITE_ONCE(event->enabled, 1);
682 break;
683
684 case LTTNG_KERNEL_ABI_KRETPROBE:
685 ret = lttng_kretprobes_event_enable_state(event, 1);
686 break;
687
688 case LTTNG_KERNEL_ABI_FUNCTION:
689 lttng_fallthrough;
690 case LTTNG_KERNEL_ABI_NOOP:
691 lttng_fallthrough;
692 default:
693 WARN_ON_ONCE(1);
694 ret = -EINVAL;
695 }
696 end:
697 mutex_unlock(&sessions_mutex);
698 return ret;
699 }
700
701 int lttng_event_disable(struct lttng_kernel_event_common *event)
702 {
703 int ret = 0;
704
705 mutex_lock(&sessions_mutex);
706 switch (event->type) {
707 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
708 {
709 struct lttng_kernel_event_recorder *event_recorder =
710 container_of(event, struct lttng_kernel_event_recorder, parent);
711
712 if (event_recorder->chan->priv->channel_type == METADATA_CHANNEL) {
713 ret = -EPERM;
714 goto end;
715 }
716 break;
717 }
718 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
719 switch (event->priv->instrumentation) {
720 case LTTNG_KERNEL_ABI_KRETPROBE:
721 ret = -EINVAL;
722 goto end;
723 default:
724 break;
725 }
726 break;
727 default:
728 break;
729 }
730
731 if (!event->enabled) {
732 ret = -EEXIST;
733 goto end;
734 }
735 switch (event->priv->instrumentation) {
736 case LTTNG_KERNEL_ABI_TRACEPOINT:
737 lttng_fallthrough;
738 case LTTNG_KERNEL_ABI_SYSCALL:
739 ret = -EINVAL;
740 break;
741
742 case LTTNG_KERNEL_ABI_KPROBE:
743 lttng_fallthrough;
744 case LTTNG_KERNEL_ABI_UPROBE:
745 WRITE_ONCE(event->enabled, 0);
746 break;
747
748 case LTTNG_KERNEL_ABI_KRETPROBE:
749 ret = lttng_kretprobes_event_enable_state(event, 0);
750 break;
751
752 case LTTNG_KERNEL_ABI_FUNCTION:
753 lttng_fallthrough;
754 case LTTNG_KERNEL_ABI_NOOP:
755 lttng_fallthrough;
756 default:
757 WARN_ON_ONCE(1);
758 ret = -EINVAL;
759 }
760 end:
761 mutex_unlock(&sessions_mutex);
762 return ret;
763 }
764
765 struct lttng_kernel_channel_buffer *lttng_channel_buffer_create(struct lttng_kernel_session *session,
766 const char *transport_name,
767 void *buf_addr,
768 size_t subbuf_size, size_t num_subbuf,
769 unsigned int switch_timer_interval,
770 unsigned int read_timer_interval,
771 enum channel_type channel_type)
772 {
773 struct lttng_kernel_channel_buffer *chan;
774 struct lttng_kernel_channel_buffer_private *chan_priv;
775 struct lttng_transport *transport = NULL;
776
777 mutex_lock(&sessions_mutex);
778 if (session->priv->been_active && channel_type != METADATA_CHANNEL)
779 goto active; /* Refuse to add channel to active session */
780 transport = lttng_transport_find(transport_name);
781 if (!transport) {
782 printk(KERN_WARNING "LTTng: transport %s not found\n",
783 transport_name);
784 goto notransport;
785 }
786 if (!try_module_get(transport->owner)) {
787 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
788 goto notransport;
789 }
790 chan = kzalloc(sizeof(struct lttng_kernel_channel_buffer), GFP_KERNEL);
791 if (!chan)
792 goto nomem;
793 chan_priv = kzalloc(sizeof(struct lttng_kernel_channel_buffer_private), GFP_KERNEL);
794 if (!chan_priv)
795 goto nomem_priv;
796 chan->priv = chan_priv;
797 chan_priv->pub = chan;
798 chan->parent.type = LTTNG_KERNEL_CHANNEL_TYPE_BUFFER;
799 chan->parent.session = session;
800 chan->priv->id = session->priv->free_chan_id++;
801 chan->ops = &transport->ops;
802 /*
803 * Note: the channel creation op already writes into the packet
804 * headers. Therefore the "chan" information used as input
805 * should be already accessible.
806 */
807 chan->priv->rb_chan = transport->ops.priv->channel_create(transport_name,
808 chan, buf_addr, subbuf_size, num_subbuf,
809 switch_timer_interval, read_timer_interval);
810 if (!chan->priv->rb_chan)
811 goto create_error;
812 chan->priv->parent.tstate = 1;
813 chan->parent.enabled = 1;
814 chan->priv->transport = transport;
815 chan->priv->channel_type = channel_type;
816 list_add(&chan->priv->node, &session->priv->chan);
817 mutex_unlock(&sessions_mutex);
818 return chan;
819
820 create_error:
821 kfree(chan_priv);
822 nomem_priv:
823 kfree(chan);
824 nomem:
825 if (transport)
826 module_put(transport->owner);
827 notransport:
828 active:
829 mutex_unlock(&sessions_mutex);
830 return NULL;
831 }
832
833 /*
834 * Only used internally at session destruction for per-cpu channels, and
835 * when metadata channel is released.
836 * Needs to be called with sessions mutex held.
837 */
838 static
839 void _lttng_channel_destroy(struct lttng_kernel_channel_buffer *chan)
840 {
841 chan->ops->priv->channel_destroy(chan->priv->rb_chan);
842 module_put(chan->priv->transport->owner);
843 list_del(&chan->priv->node);
844 lttng_kernel_destroy_context(chan->priv->ctx);
845 kfree(chan->priv);
846 kfree(chan);
847 }
848
849 void lttng_metadata_channel_destroy(struct lttng_kernel_channel_buffer *chan)
850 {
851 BUG_ON(chan->priv->channel_type != METADATA_CHANNEL);
852
853 /* Protect the metadata cache with the sessions_mutex. */
854 mutex_lock(&sessions_mutex);
855 _lttng_channel_destroy(chan);
856 mutex_unlock(&sessions_mutex);
857 }
858 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
859
860 static
861 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
862 {
863 stream->finalized = 1;
864 wake_up_interruptible(&stream->read_wait);
865 }
866
867 static
868 bool lttng_kernel_event_id_available(struct lttng_event_enabler_common *event_enabler)
869 {
870 struct lttng_kernel_abi_event *event_param = &event_enabler->event_param;
871 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
872
873 switch (event_enabler->enabler_type) {
874 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
875 {
876 struct lttng_event_recorder_enabler *event_recorder_enabler =
877 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
878 struct lttng_kernel_channel_buffer *chan = event_recorder_enabler->chan;
879
880 switch (itype) {
881 case LTTNG_KERNEL_ABI_TRACEPOINT:
882 lttng_fallthrough;
883 case LTTNG_KERNEL_ABI_KPROBE:
884 lttng_fallthrough;
885 case LTTNG_KERNEL_ABI_SYSCALL:
886 lttng_fallthrough;
887 case LTTNG_KERNEL_ABI_UPROBE:
888 if (chan->priv->free_event_id == -1U)
889 return false;
890 return true;
891 case LTTNG_KERNEL_ABI_KRETPROBE:
892 /* kretprobes require 2 event IDs. */
893 if (chan->priv->free_event_id >= -2U)
894 return false;
895 return true;
896 default:
897 WARN_ON_ONCE(1);
898 return false;
899 }
900 }
901 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
902 return true;
903 default:
904 WARN_ON_ONCE(1);
905 return false;
906 }
907 }
908
909 static
910 struct lttng_kernel_event_common *lttng_kernel_event_alloc(struct lttng_event_enabler_common *event_enabler)
911 {
912 struct lttng_kernel_abi_event *event_param = &event_enabler->event_param;
913 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
914
915 switch (event_enabler->enabler_type) {
916 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
917 {
918 struct lttng_event_recorder_enabler *event_recorder_enabler =
919 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
920 struct lttng_kernel_event_recorder *event_recorder;
921 struct lttng_kernel_event_recorder_private *event_recorder_priv;
922 struct lttng_kernel_channel_buffer *chan = event_recorder_enabler->chan;
923
924 event_recorder = kmem_cache_zalloc(event_recorder_cache, GFP_KERNEL);
925 if (!event_recorder)
926 return NULL;
927 event_recorder_priv = kmem_cache_zalloc(event_recorder_private_cache, GFP_KERNEL);
928 if (!event_recorder_priv) {
929 kmem_cache_free(event_recorder_private_cache, event_recorder);
930 return NULL;
931 }
932 event_recorder_priv->pub = event_recorder;
933 event_recorder_priv->parent.pub = &event_recorder->parent;
934 event_recorder->priv = event_recorder_priv;
935 event_recorder->parent.priv = &event_recorder_priv->parent;
936
937 event_recorder->parent.type = LTTNG_KERNEL_EVENT_TYPE_RECORDER;
938 event_recorder->parent.run_filter = lttng_kernel_interpret_event_filter;
939 event_recorder->priv->parent.instrumentation = itype;
940 INIT_LIST_HEAD(&event_recorder->priv->parent.filter_bytecode_runtime_head);
941 INIT_LIST_HEAD(&event_recorder->priv->parent.enablers_ref_head);
942
943 event_recorder->chan = chan;
944 event_recorder->priv->id = chan->priv->free_event_id++;
945 return &event_recorder->parent;
946 }
947 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
948 {
949 struct lttng_event_notifier_enabler *event_notifier_enabler =
950 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
951 struct lttng_kernel_event_notifier *event_notifier;
952 struct lttng_kernel_event_notifier_private *event_notifier_priv;
953
954 event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
955 if (!event_notifier)
956 return NULL;
957 event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
958 if (!event_notifier_priv) {
959 kmem_cache_free(event_notifier_private_cache, event_notifier);
960 return NULL;
961 }
962 event_notifier_priv->pub = event_notifier;
963 event_notifier_priv->parent.pub = &event_notifier->parent;
964 event_notifier->priv = event_notifier_priv;
965 event_notifier->parent.priv = &event_notifier_priv->parent;
966
967 event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
968 event_notifier->parent.run_filter = lttng_kernel_interpret_event_filter;
969 event_notifier->priv->parent.instrumentation = itype;
970 event_notifier->priv->parent.user_token = event_enabler->user_token;
971 INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
972 INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
973
974 event_notifier->priv->group = event_notifier_enabler->group;
975 event_notifier->priv->error_counter_index = event_notifier_enabler->error_counter_index;
976 event_notifier->priv->num_captures = 0;
977 event_notifier->notification_send = lttng_event_notifier_notification_send;
978 INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
979 return &event_notifier->parent;
980 }
981 default:
982 return NULL;
983 }
984 }
985
986 static
987 void lttng_kernel_event_free(struct lttng_kernel_event_common *event)
988 {
989 switch (event->type) {
990 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
991 {
992 struct lttng_kernel_event_recorder *event_recorder =
993 container_of(event, struct lttng_kernel_event_recorder, parent);
994
995 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
996 kmem_cache_free(event_recorder_cache, event_recorder);
997 break;
998 }
999 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1000 {
1001 struct lttng_kernel_event_notifier *event_notifier =
1002 container_of(event, struct lttng_kernel_event_notifier, parent);
1003
1004 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1005 kmem_cache_free(event_notifier_cache, event_notifier);
1006 break;
1007 }
1008 default:
1009 WARN_ON_ONCE(1);
1010 }
1011 }
1012
1013 static
1014 int lttng_kernel_event_notifier_clear_error_counter(struct lttng_kernel_event_common *event)
1015 {
1016 switch (event->type) {
1017 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1018 return 0;
1019 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1020 {
1021 struct lttng_kernel_event_notifier *event_notifier =
1022 container_of(event, struct lttng_kernel_event_notifier, parent);
1023 struct lttng_counter *error_counter;
1024 struct lttng_event_notifier_group *event_notifier_group = event_notifier->priv->group;
1025 size_t dimension_index[1];
1026 int ret;
1027
1028 /*
1029 * Clear the error counter bucket. The sessiond keeps track of which
1030 * bucket is currently in use. We trust it. The session lock
1031 * synchronizes against concurrent creation of the error
1032 * counter.
1033 */
1034 error_counter = event_notifier_group->error_counter;
1035 if (!error_counter)
1036 return 0;
1037 /*
1038 * Check that the index is within the boundary of the counter.
1039 */
1040 if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
1041 printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
1042 event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
1043 return -EINVAL;
1044 }
1045
1046 dimension_index[0] = event_notifier->priv->error_counter_index;
1047 ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
1048 if (ret) {
1049 printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
1050 event_notifier->priv->error_counter_index);
1051 return -EINVAL;
1052 }
1053 return 0;
1054 }
1055 default:
1056 return -EINVAL;
1057 }
1058 }
1059
1060 /*
1061 * Supports event creation while tracing session is active.
1062 * Needs to be called with sessions mutex held.
1063 */
1064 static
1065 struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct lttng_event_recorder_enabler *event_enabler,
1066 const struct lttng_kernel_event_desc *event_desc)
1067 {
1068 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_enabler->parent);
1069 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(&event_enabler->parent);
1070 struct lttng_kernel_abi_event *event_param = &event_enabler->parent.event_param;
1071 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
1072 struct lttng_kernel_event_common_private *event_priv;
1073 struct lttng_kernel_event_common *event;
1074 struct lttng_kernel_event_recorder *event_recorder;
1075 const char *event_name;
1076 struct hlist_head *head;
1077 int ret;
1078
1079 if (!lttng_kernel_event_id_available(&event_enabler->parent)) {
1080 ret = -EMFILE;
1081 goto full;
1082 }
1083
1084 switch (itype) {
1085 case LTTNG_KERNEL_ABI_TRACEPOINT:
1086 event_name = event_desc->event_name;
1087 break;
1088
1089 case LTTNG_KERNEL_ABI_KPROBE:
1090 lttng_fallthrough;
1091 case LTTNG_KERNEL_ABI_UPROBE:
1092 lttng_fallthrough;
1093 case LTTNG_KERNEL_ABI_KRETPROBE:
1094 lttng_fallthrough;
1095 case LTTNG_KERNEL_ABI_SYSCALL:
1096 event_name = event_param->name;
1097 break;
1098
1099 case LTTNG_KERNEL_ABI_FUNCTION:
1100 lttng_fallthrough;
1101 case LTTNG_KERNEL_ABI_NOOP:
1102 lttng_fallthrough;
1103 default:
1104 WARN_ON_ONCE(1);
1105 ret = -EINVAL;
1106 goto type_error;
1107 }
1108
1109 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, event_name);
1110 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
1111 if (lttng_event_enabler_event_name_match_event(&event_enabler->parent, event_name, event_priv->pub)) {
1112 ret = -EEXIST;
1113 goto exist;
1114 }
1115 }
1116
1117 event = lttng_kernel_event_alloc(&event_enabler->parent);
1118 if (!event) {
1119 ret = -ENOMEM;
1120 goto alloc_error;
1121 }
1122 event_recorder = container_of(event, struct lttng_kernel_event_recorder, parent);
1123
1124 switch (itype) {
1125 case LTTNG_KERNEL_ABI_TRACEPOINT:
1126 /* Event will be enabled by enabler sync. */
1127 event->enabled = 0;
1128 event->priv->registered = 0;
1129 event->priv->desc = lttng_event_desc_get(event_name);
1130 if (!event->priv->desc) {
1131 ret = -ENOENT;
1132 goto register_error;
1133 }
1134 /* Populate lttng_event structure before event registration. */
1135 smp_wmb();
1136 break;
1137
1138 case LTTNG_KERNEL_ABI_KPROBE:
1139 /*
1140 * Needs to be explicitly enabled after creation, since
1141 * we may want to apply filters.
1142 */
1143 event->enabled = 0;
1144 event->priv->registered = 1;
1145 /*
1146 * Populate lttng_event structure before event
1147 * registration.
1148 */
1149 smp_wmb();
1150 ret = lttng_kprobes_register_event(event_name,
1151 event_param->u.kprobe.symbol_name,
1152 event_param->u.kprobe.offset,
1153 event_param->u.kprobe.addr,
1154 event);
1155 if (ret) {
1156 ret = -EINVAL;
1157 goto register_error;
1158 }
1159 ret = try_module_get(event->priv->desc->owner);
1160 WARN_ON_ONCE(!ret);
1161 break;
1162
1163 case LTTNG_KERNEL_ABI_KRETPROBE:
1164 {
1165 struct lttng_kernel_event_common *event_return;
1166
1167 /* kretprobe defines 2 events */
1168 /*
1169 * Needs to be explicitly enabled after creation, since
1170 * we may want to apply filters.
1171 */
1172 event->enabled = 0;
1173 event->priv->registered = 1;
1174
1175 event_return = lttng_kernel_event_alloc(&event_enabler->parent);
1176 if (!event) {
1177 ret = -ENOMEM;
1178 goto alloc_error;
1179 }
1180
1181 event_return->enabled = 0;
1182 event_return->priv->registered = 1;
1183
1184 /*
1185 * Populate lttng_event structure before kretprobe registration.
1186 */
1187 smp_wmb();
1188 ret = lttng_kretprobes_register(event_name,
1189 event_param->u.kretprobe.symbol_name,
1190 event_param->u.kretprobe.offset,
1191 event_param->u.kretprobe.addr,
1192 event, event_return);
1193 if (ret) {
1194 lttng_kernel_event_free(event_return);
1195 ret = -EINVAL;
1196 goto register_error;
1197 }
1198 /* Take 2 refs on the module: one per event. */
1199 ret = try_module_get(event->priv->desc->owner);
1200 WARN_ON_ONCE(!ret);
1201 ret = try_module_get(event_return->priv->desc->owner);
1202 WARN_ON_ONCE(!ret);
1203 ret = _lttng_event_recorder_metadata_statedump(event_return);
1204 WARN_ON_ONCE(ret > 0);
1205 if (ret) {
1206 lttng_kernel_event_free(event_return);
1207 module_put(event_return->priv->desc->owner);
1208 module_put(event->priv->desc->owner);
1209 goto statedump_error;
1210 }
1211 list_add(&event_return->priv->node, event_list_head);
1212 break;
1213 }
1214
1215 case LTTNG_KERNEL_ABI_SYSCALL:
1216 /*
1217 * Needs to be explicitly enabled after creation, since
1218 * we may want to apply filters.
1219 */
1220 event->enabled = 0;
1221 event->priv->registered = 0;
1222 event->priv->desc = event_desc;
1223 switch (event_param->u.syscall.entryexit) {
1224 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1225 ret = -EINVAL;
1226 goto register_error;
1227 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1228 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1229 break;
1230 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1231 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1232 break;
1233 }
1234 switch (event_param->u.syscall.abi) {
1235 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1236 ret = -EINVAL;
1237 goto register_error;
1238 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1239 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1240 break;
1241 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1242 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1243 break;
1244 }
1245 if (!event->priv->desc) {
1246 ret = -EINVAL;
1247 goto register_error;
1248 }
1249 break;
1250
1251 case LTTNG_KERNEL_ABI_UPROBE:
1252 /*
1253 * Needs to be explicitly enabled after creation, since
1254 * we may want to apply filters.
1255 */
1256 event->enabled = 0;
1257 event->priv->registered = 1;
1258
1259 /*
1260 * Populate lttng_event structure before event
1261 * registration.
1262 */
1263 smp_wmb();
1264
1265 ret = lttng_uprobes_register_event(event_param->name,
1266 event_param->u.uprobe.fd,
1267 event);
1268 if (ret)
1269 goto register_error;
1270 ret = try_module_get(event->priv->desc->owner);
1271 WARN_ON_ONCE(!ret);
1272 break;
1273
1274 case LTTNG_KERNEL_ABI_FUNCTION:
1275 lttng_fallthrough;
1276 case LTTNG_KERNEL_ABI_NOOP:
1277 lttng_fallthrough;
1278 default:
1279 WARN_ON_ONCE(1);
1280 ret = -EINVAL;
1281 goto register_error;
1282 }
1283 ret = _lttng_event_recorder_metadata_statedump(event);
1284 WARN_ON_ONCE(ret > 0);
1285 if (ret) {
1286 goto statedump_error;
1287 }
1288 hlist_add_head(&event->priv->hlist_node, head);
1289 list_add(&event->priv->node, event_list_head);
1290 return event_recorder;
1291
1292 statedump_error:
1293 /* If a statedump error occurs, events will not be readable. */
1294 register_error:
1295 lttng_kernel_event_free(event);
1296 alloc_error:
1297 exist:
1298 type_error:
1299 full:
1300 return ERR_PTR(ret);
1301 }
1302
1303 static
1304 struct lttng_kernel_event_notifier *_lttng_kernel_event_notifier_create(struct lttng_event_notifier_enabler *event_enabler,
1305 const struct lttng_kernel_event_desc *event_desc)
1306 {
1307 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_enabler->parent);
1308 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(&event_enabler->parent);
1309 struct lttng_kernel_abi_event *event_param = &event_enabler->parent.event_param;
1310 enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
1311 struct lttng_kernel_event_common_private *event_priv;
1312 struct lttng_kernel_event_common *event;
1313 struct lttng_kernel_event_notifier *event_notifier;
1314 const char *event_name;
1315 struct hlist_head *head;
1316 int ret;
1317
1318 switch (itype) {
1319 case LTTNG_KERNEL_ABI_TRACEPOINT:
1320 event_name = event_desc->event_name;
1321 break;
1322
1323 case LTTNG_KERNEL_ABI_KPROBE:
1324 lttng_fallthrough;
1325 case LTTNG_KERNEL_ABI_UPROBE:
1326 lttng_fallthrough;
1327 case LTTNG_KERNEL_ABI_SYSCALL:
1328 event_name = event_param->name;
1329 break;
1330
1331 case LTTNG_KERNEL_ABI_KRETPROBE:
1332 lttng_fallthrough;
1333 case LTTNG_KERNEL_ABI_FUNCTION:
1334 lttng_fallthrough;
1335 case LTTNG_KERNEL_ABI_NOOP:
1336 lttng_fallthrough;
1337 default:
1338 WARN_ON_ONCE(1);
1339 ret = -EINVAL;
1340 goto type_error;
1341 }
1342
1343 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, event_name);
1344 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
1345 if (lttng_event_enabler_event_name_match_event(&event_enabler->parent, event_name, event_priv->pub)) {
1346 ret = -EEXIST;
1347 goto exist;
1348 }
1349 }
1350
1351 event = lttng_kernel_event_alloc(&event_enabler->parent);
1352 if (!event) {
1353 ret = -ENOMEM;
1354 goto alloc_error;
1355 }
1356 event_notifier = container_of(event, struct lttng_kernel_event_notifier, parent);
1357
1358 switch (itype) {
1359 case LTTNG_KERNEL_ABI_TRACEPOINT:
1360 /* Event will be enabled by enabler sync. */
1361 event->enabled = 0;
1362 event->priv->registered = 0;
1363 event->priv->desc = lttng_event_desc_get(event_name);
1364 if (!event->priv->desc) {
1365 ret = -ENOENT;
1366 goto register_error;
1367 }
1368 /* Populate lttng_event_notifier structure before event registration. */
1369 smp_wmb();
1370 break;
1371
1372 case LTTNG_KERNEL_ABI_KPROBE:
1373 /*
1374 * Needs to be explicitly enabled after creation, since
1375 * we may want to apply filters.
1376 */
1377 event->enabled = 0;
1378 event->priv->registered = 1;
1379 /*
1380 * Populate lttng_event_notifier structure before event
1381 * registration.
1382 */
1383 smp_wmb();
1384 ret = lttng_kprobes_register_event(event_param->u.kprobe.symbol_name,
1385 event_param->u.kprobe.symbol_name,
1386 event_param->u.kprobe.offset,
1387 event_param->u.kprobe.addr,
1388 event);
1389 if (ret) {
1390 ret = -EINVAL;
1391 goto register_error;
1392 }
1393 ret = try_module_get(event->priv->desc->owner);
1394 WARN_ON_ONCE(!ret);
1395 break;
1396
1397 case LTTNG_KERNEL_ABI_SYSCALL:
1398 /*
1399 * Needs to be explicitly enabled after creation, since
1400 * we may want to apply filters.
1401 */
1402 event->enabled = 0;
1403 event->priv->registered = 0;
1404 event->priv->desc = event_desc;
1405 switch (event_param->u.syscall.entryexit) {
1406 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1407 ret = -EINVAL;
1408 goto register_error;
1409 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1410 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
1411 break;
1412 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1413 event->priv->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
1414 break;
1415 }
1416 switch (event_param->u.syscall.abi) {
1417 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1418 ret = -EINVAL;
1419 goto register_error;
1420 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
1421 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
1422 break;
1423 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
1424 event->priv->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
1425 break;
1426 }
1427
1428 if (!event->priv->desc) {
1429 ret = -EINVAL;
1430 goto register_error;
1431 }
1432 break;
1433
1434 case LTTNG_KERNEL_ABI_UPROBE:
1435 /*
1436 * Needs to be explicitly enabled after creation, since
1437 * we may want to apply filters.
1438 */
1439 event->enabled = 0;
1440 event->priv->registered = 1;
1441
1442 /*
1443 * Populate lttng_event_notifier structure before
1444 * event_notifier registration.
1445 */
1446 smp_wmb();
1447
1448 ret = lttng_uprobes_register_event(event_param->name,
1449 event_param->u.uprobe.fd,
1450 event);
1451 if (ret)
1452 goto register_error;
1453 ret = try_module_get(event->priv->desc->owner);
1454 WARN_ON_ONCE(!ret);
1455 break;
1456
1457 case LTTNG_KERNEL_ABI_KRETPROBE:
1458 lttng_fallthrough;
1459 case LTTNG_KERNEL_ABI_FUNCTION:
1460 lttng_fallthrough;
1461 case LTTNG_KERNEL_ABI_NOOP:
1462 lttng_fallthrough;
1463 default:
1464 WARN_ON_ONCE(1);
1465 ret = -EINVAL;
1466 goto register_error;
1467 }
1468
1469 ret = lttng_kernel_event_notifier_clear_error_counter(event);
1470 if (ret)
1471 goto register_error;
1472
1473 list_add(&event->priv->node, event_list_head);
1474 hlist_add_head(&event->priv->hlist_node, head);
1475
1476 return event_notifier;
1477
1478 register_error:
1479 lttng_kernel_event_free(event);
1480 alloc_error:
1481 exist:
1482 type_error:
1483 return ERR_PTR(ret);
1484 }
1485
1486 struct lttng_kernel_event_common *_lttng_kernel_event_create(struct lttng_event_enabler_common *event_enabler,
1487 const struct lttng_kernel_event_desc *event_desc)
1488 {
1489 switch (event_enabler->enabler_type) {
1490 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
1491 {
1492 struct lttng_event_recorder_enabler *event_recorder_enabler =
1493 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
1494 struct lttng_kernel_event_recorder *event_recorder;
1495
1496 event_recorder = _lttng_kernel_event_recorder_create(event_recorder_enabler, event_desc);
1497 if (!event_recorder)
1498 return NULL;
1499 return &event_recorder->parent;
1500 }
1501 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
1502 {
1503 struct lttng_event_notifier_enabler *event_notifier_enabler =
1504 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
1505 struct lttng_kernel_event_notifier *event_notifier;
1506
1507 event_notifier = _lttng_kernel_event_notifier_create(event_notifier_enabler, event_desc);
1508 if (!event_notifier)
1509 return NULL;
1510 return &event_notifier->parent;
1511 }
1512 default:
1513 return NULL;
1514 }
1515 }
1516
1517 struct lttng_kernel_event_common *lttng_kernel_event_create(struct lttng_event_enabler_common *event_enabler,
1518 const struct lttng_kernel_event_desc *event_desc)
1519 {
1520 struct lttng_kernel_event_common *event;
1521
1522 mutex_lock(&sessions_mutex);
1523 event = _lttng_kernel_event_create(event_enabler, event_desc);
1524 mutex_unlock(&sessions_mutex);
1525 return event;
1526 }
1527
1528
1529
1530 int lttng_kernel_counter_read(struct lttng_counter *counter,
1531 const size_t *dim_indexes, int32_t cpu,
1532 int64_t *val, bool *overflow, bool *underflow)
1533 {
1534 return counter->ops->counter_read(counter->counter, dim_indexes,
1535 cpu, val, overflow, underflow);
1536 }
1537
1538 int lttng_kernel_counter_aggregate(struct lttng_counter *counter,
1539 const size_t *dim_indexes, int64_t *val,
1540 bool *overflow, bool *underflow)
1541 {
1542 return counter->ops->counter_aggregate(counter->counter, dim_indexes,
1543 val, overflow, underflow);
1544 }
1545
1546 int lttng_kernel_counter_clear(struct lttng_counter *counter,
1547 const size_t *dim_indexes)
1548 {
1549 return counter->ops->counter_clear(counter->counter, dim_indexes);
1550 }
1551
1552 /* Only used for tracepoints for now. */
1553 static
1554 void register_event(struct lttng_kernel_event_common *event)
1555 {
1556 const struct lttng_kernel_event_desc *desc;
1557 int ret = -EINVAL;
1558
1559 if (event->priv->registered)
1560 return;
1561
1562 desc = event->priv->desc;
1563 switch (event->priv->instrumentation) {
1564 case LTTNG_KERNEL_ABI_TRACEPOINT:
1565 ret = lttng_wrapper_tracepoint_probe_register(desc->event_kname,
1566 desc->tp_class->probe_callback,
1567 event);
1568 break;
1569
1570 case LTTNG_KERNEL_ABI_SYSCALL:
1571 ret = lttng_syscall_filter_enable_event(event);
1572 break;
1573
1574 case LTTNG_KERNEL_ABI_KPROBE:
1575 lttng_fallthrough;
1576 case LTTNG_KERNEL_ABI_UPROBE:
1577 ret = 0;
1578 break;
1579
1580 case LTTNG_KERNEL_ABI_KRETPROBE:
1581 switch (event->type) {
1582 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1583 ret = 0;
1584 break;
1585 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1586 WARN_ON_ONCE(1);
1587 break;
1588 }
1589 break;
1590
1591 case LTTNG_KERNEL_ABI_FUNCTION:
1592 lttng_fallthrough;
1593 case LTTNG_KERNEL_ABI_NOOP:
1594 lttng_fallthrough;
1595 default:
1596 WARN_ON_ONCE(1);
1597 }
1598 if (!ret)
1599 event->priv->registered = 1;
1600 }
1601
1602 int _lttng_event_unregister(struct lttng_kernel_event_common *event)
1603 {
1604 struct lttng_kernel_event_common_private *event_priv = event->priv;
1605 const struct lttng_kernel_event_desc *desc;
1606 int ret = -EINVAL;
1607
1608 if (!event_priv->registered)
1609 return 0;
1610
1611 desc = event_priv->desc;
1612 switch (event_priv->instrumentation) {
1613 case LTTNG_KERNEL_ABI_TRACEPOINT:
1614 ret = lttng_wrapper_tracepoint_probe_unregister(event_priv->desc->event_kname,
1615 event_priv->desc->tp_class->probe_callback,
1616 event);
1617 break;
1618
1619 case LTTNG_KERNEL_ABI_KPROBE:
1620 lttng_kprobes_unregister_event(event);
1621 ret = 0;
1622 break;
1623
1624 case LTTNG_KERNEL_ABI_KRETPROBE:
1625 switch (event->type) {
1626 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1627 lttng_kretprobes_unregister(event);
1628 ret = 0;
1629 break;
1630 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1631 WARN_ON_ONCE(1);
1632 break;
1633 }
1634 break;
1635
1636 case LTTNG_KERNEL_ABI_SYSCALL:
1637 ret = lttng_syscall_filter_disable_event(event);
1638 break;
1639
1640 case LTTNG_KERNEL_ABI_NOOP:
1641 switch (event->type) {
1642 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1643 ret = 0;
1644 break;
1645 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1646 WARN_ON_ONCE(1);
1647 break;
1648 }
1649 break;
1650
1651 case LTTNG_KERNEL_ABI_UPROBE:
1652 lttng_uprobes_unregister_event(event);
1653 ret = 0;
1654 break;
1655
1656 case LTTNG_KERNEL_ABI_FUNCTION:
1657 lttng_fallthrough;
1658 default:
1659 WARN_ON_ONCE(1);
1660 }
1661 if (!ret)
1662 event_priv->registered = 0;
1663 return ret;
1664 }
1665
1666 /*
1667 * Only used internally at session destruction.
1668 */
1669 static
1670 void _lttng_event_destroy(struct lttng_kernel_event_common *event)
1671 {
1672 struct lttng_kernel_event_common_private *event_priv = event->priv;
1673 struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1674
1675 lttng_free_event_filter_runtime(event);
1676 /* Free event enabler refs */
1677 list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1678 &event_priv->enablers_ref_head, node)
1679 kfree(enabler_ref);
1680
1681 switch (event->type) {
1682 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1683 {
1684 struct lttng_kernel_event_recorder *event_recorder =
1685 container_of(event, struct lttng_kernel_event_recorder, parent);
1686
1687 switch (event_priv->instrumentation) {
1688 case LTTNG_KERNEL_ABI_TRACEPOINT:
1689 lttng_event_desc_put(event_priv->desc);
1690 break;
1691
1692 case LTTNG_KERNEL_ABI_KPROBE:
1693 module_put(event_priv->desc->owner);
1694 lttng_kprobes_destroy_event_private(&event_recorder->parent);
1695 break;
1696
1697 case LTTNG_KERNEL_ABI_KRETPROBE:
1698 module_put(event_priv->desc->owner);
1699 lttng_kretprobes_destroy_private(&event_recorder->parent);
1700 break;
1701
1702 case LTTNG_KERNEL_ABI_SYSCALL:
1703 break;
1704
1705 case LTTNG_KERNEL_ABI_UPROBE:
1706 module_put(event_priv->desc->owner);
1707 lttng_uprobes_destroy_event_private(&event_recorder->parent);
1708 break;
1709
1710 case LTTNG_KERNEL_ABI_FUNCTION:
1711 lttng_fallthrough;
1712 case LTTNG_KERNEL_ABI_NOOP:
1713 lttng_fallthrough;
1714 default:
1715 WARN_ON_ONCE(1);
1716 }
1717 list_del(&event_recorder->priv->parent.node);
1718 kmem_cache_free(event_recorder_private_cache, event_recorder->priv);
1719 kmem_cache_free(event_recorder_cache, event_recorder);
1720 break;
1721 }
1722 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1723 {
1724 struct lttng_kernel_event_notifier *event_notifier =
1725 container_of(event, struct lttng_kernel_event_notifier, parent);
1726
1727 switch (event_notifier->priv->parent.instrumentation) {
1728 case LTTNG_KERNEL_ABI_TRACEPOINT:
1729 lttng_event_desc_put(event_notifier->priv->parent.desc);
1730 break;
1731
1732 case LTTNG_KERNEL_ABI_KPROBE:
1733 module_put(event_notifier->priv->parent.desc->owner);
1734 lttng_kprobes_destroy_event_private(&event_notifier->parent);
1735 break;
1736
1737 case LTTNG_KERNEL_ABI_SYSCALL:
1738 break;
1739
1740 case LTTNG_KERNEL_ABI_UPROBE:
1741 module_put(event_notifier->priv->parent.desc->owner);
1742 lttng_uprobes_destroy_event_private(&event_notifier->parent);
1743 break;
1744
1745 case LTTNG_KERNEL_ABI_KRETPROBE:
1746 lttng_fallthrough;
1747 case LTTNG_KERNEL_ABI_FUNCTION:
1748 lttng_fallthrough;
1749 case LTTNG_KERNEL_ABI_NOOP:
1750 lttng_fallthrough;
1751 default:
1752 WARN_ON_ONCE(1);
1753 }
1754 list_del(&event_notifier->priv->parent.node);
1755 kmem_cache_free(event_notifier_private_cache, event_notifier->priv);
1756 kmem_cache_free(event_notifier_cache, event_notifier);
1757 break;
1758 }
1759 default:
1760 WARN_ON_ONCE(1);
1761 }
1762 }
1763
1764 struct lttng_kernel_id_tracker *get_tracker(struct lttng_kernel_session *session,
1765 enum tracker_type tracker_type)
1766 {
1767 switch (tracker_type) {
1768 case TRACKER_PID:
1769 return &session->pid_tracker;
1770 case TRACKER_VPID:
1771 return &session->vpid_tracker;
1772 case TRACKER_UID:
1773 return &session->uid_tracker;
1774 case TRACKER_VUID:
1775 return &session->vuid_tracker;
1776 case TRACKER_GID:
1777 return &session->gid_tracker;
1778 case TRACKER_VGID:
1779 return &session->vgid_tracker;
1780 default:
1781 WARN_ON_ONCE(1);
1782 return NULL;
1783 }
1784 }
1785
1786 int lttng_session_track_id(struct lttng_kernel_session *session,
1787 enum tracker_type tracker_type, int id)
1788 {
1789 struct lttng_kernel_id_tracker *tracker;
1790 int ret;
1791
1792 tracker = get_tracker(session, tracker_type);
1793 if (!tracker)
1794 return -EINVAL;
1795 if (id < -1)
1796 return -EINVAL;
1797 mutex_lock(&sessions_mutex);
1798 if (id == -1) {
1799 /* track all ids: destroy tracker. */
1800 lttng_id_tracker_destroy(tracker, true);
1801 ret = 0;
1802 } else {
1803 ret = lttng_id_tracker_add(tracker, id);
1804 }
1805 mutex_unlock(&sessions_mutex);
1806 return ret;
1807 }
1808
1809 int lttng_session_untrack_id(struct lttng_kernel_session *session,
1810 enum tracker_type tracker_type, int id)
1811 {
1812 struct lttng_kernel_id_tracker *tracker;
1813 int ret;
1814
1815 tracker = get_tracker(session, tracker_type);
1816 if (!tracker)
1817 return -EINVAL;
1818 if (id < -1)
1819 return -EINVAL;
1820 mutex_lock(&sessions_mutex);
1821 if (id == -1) {
1822 /* untrack all ids: replace by empty tracker. */
1823 ret = lttng_id_tracker_empty_set(tracker);
1824 } else {
1825 ret = lttng_id_tracker_del(tracker, id);
1826 }
1827 mutex_unlock(&sessions_mutex);
1828 return ret;
1829 }
1830
1831 static
1832 void *id_list_start(struct seq_file *m, loff_t *pos)
1833 {
1834 struct lttng_kernel_id_tracker *id_tracker = m->private;
1835 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1836 struct lttng_id_hash_node *e;
1837 int iter = 0, i;
1838
1839 mutex_lock(&sessions_mutex);
1840 if (id_tracker_p) {
1841 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1842 struct hlist_head *head = &id_tracker_p->id_hash[i];
1843
1844 lttng_hlist_for_each_entry(e, head, hlist) {
1845 if (iter++ >= *pos)
1846 return e;
1847 }
1848 }
1849 } else {
1850 /* ID tracker disabled. */
1851 if (iter >= *pos && iter == 0) {
1852 return id_tracker_p; /* empty tracker */
1853 }
1854 iter++;
1855 }
1856 /* End of list */
1857 return NULL;
1858 }
1859
1860 /* Called with sessions_mutex held. */
1861 static
1862 void *id_list_next(struct seq_file *m, void *p, loff_t *ppos)
1863 {
1864 struct lttng_kernel_id_tracker *id_tracker = m->private;
1865 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1866 struct lttng_id_hash_node *e;
1867 int iter = 0, i;
1868
1869 (*ppos)++;
1870 if (id_tracker_p) {
1871 for (i = 0; i < LTTNG_ID_TABLE_SIZE; i++) {
1872 struct hlist_head *head = &id_tracker_p->id_hash[i];
1873
1874 lttng_hlist_for_each_entry(e, head, hlist) {
1875 if (iter++ >= *ppos)
1876 return e;
1877 }
1878 }
1879 } else {
1880 /* ID tracker disabled. */
1881 if (iter >= *ppos && iter == 0)
1882 return p; /* empty tracker */
1883 iter++;
1884 }
1885
1886 /* End of list */
1887 return NULL;
1888 }
1889
1890 static
1891 void id_list_stop(struct seq_file *m, void *p)
1892 {
1893 mutex_unlock(&sessions_mutex);
1894 }
1895
1896 static
1897 int id_list_show(struct seq_file *m, void *p)
1898 {
1899 struct lttng_kernel_id_tracker *id_tracker = m->private;
1900 struct lttng_kernel_id_tracker_rcu *id_tracker_p = id_tracker->p;
1901 int id;
1902
1903 if (p == id_tracker_p) {
1904 /* Tracker disabled. */
1905 id = -1;
1906 } else {
1907 const struct lttng_id_hash_node *e = p;
1908
1909 id = lttng_id_tracker_get_node_id(e);
1910 }
1911 switch (id_tracker->priv->tracker_type) {
1912 case TRACKER_PID:
1913 seq_printf(m, "process { pid = %d; };\n", id);
1914 break;
1915 case TRACKER_VPID:
1916 seq_printf(m, "process { vpid = %d; };\n", id);
1917 break;
1918 case TRACKER_UID:
1919 seq_printf(m, "user { uid = %d; };\n", id);
1920 break;
1921 case TRACKER_VUID:
1922 seq_printf(m, "user { vuid = %d; };\n", id);
1923 break;
1924 case TRACKER_GID:
1925 seq_printf(m, "group { gid = %d; };\n", id);
1926 break;
1927 case TRACKER_VGID:
1928 seq_printf(m, "group { vgid = %d; };\n", id);
1929 break;
1930 default:
1931 seq_printf(m, "UNKNOWN { field = %d };\n", id);
1932 }
1933 return 0;
1934 }
1935
1936 static
1937 const struct seq_operations lttng_tracker_ids_list_seq_ops = {
1938 .start = id_list_start,
1939 .next = id_list_next,
1940 .stop = id_list_stop,
1941 .show = id_list_show,
1942 };
1943
1944 static
1945 int lttng_tracker_ids_list_open(struct inode *inode, struct file *file)
1946 {
1947 return seq_open(file, &lttng_tracker_ids_list_seq_ops);
1948 }
1949
1950 static
1951 int lttng_tracker_ids_list_release(struct inode *inode, struct file *file)
1952 {
1953 struct seq_file *m = file->private_data;
1954 struct lttng_kernel_id_tracker *id_tracker = m->private;
1955 int ret;
1956
1957 WARN_ON_ONCE(!id_tracker);
1958 ret = seq_release(inode, file);
1959 if (!ret)
1960 fput(id_tracker->priv->session->priv->file);
1961 return ret;
1962 }
1963
1964 const struct file_operations lttng_tracker_ids_list_fops = {
1965 .owner = THIS_MODULE,
1966 .open = lttng_tracker_ids_list_open,
1967 .read = seq_read,
1968 .llseek = seq_lseek,
1969 .release = lttng_tracker_ids_list_release,
1970 };
1971
1972 int lttng_session_list_tracker_ids(struct lttng_kernel_session *session,
1973 enum tracker_type tracker_type)
1974 {
1975 struct file *tracker_ids_list_file;
1976 struct seq_file *m;
1977 int file_fd, ret;
1978
1979 file_fd = lttng_get_unused_fd();
1980 if (file_fd < 0) {
1981 ret = file_fd;
1982 goto fd_error;
1983 }
1984
1985 tracker_ids_list_file = anon_inode_getfile("[lttng_tracker_ids_list]",
1986 &lttng_tracker_ids_list_fops,
1987 NULL, O_RDWR);
1988 if (IS_ERR(tracker_ids_list_file)) {
1989 ret = PTR_ERR(tracker_ids_list_file);
1990 goto file_error;
1991 }
1992 if (!atomic_long_add_unless(&session->priv->file->f_count, 1, LONG_MAX)) {
1993 ret = -EOVERFLOW;
1994 goto refcount_error;
1995 }
1996 ret = lttng_tracker_ids_list_fops.open(NULL, tracker_ids_list_file);
1997 if (ret < 0)
1998 goto open_error;
1999 m = tracker_ids_list_file->private_data;
2000
2001 m->private = get_tracker(session, tracker_type);
2002 BUG_ON(!m->private);
2003 fd_install(file_fd, tracker_ids_list_file);
2004
2005 return file_fd;
2006
2007 open_error:
2008 atomic_long_dec(&session->priv->file->f_count);
2009 refcount_error:
2010 fput(tracker_ids_list_file);
2011 file_error:
2012 put_unused_fd(file_fd);
2013 fd_error:
2014 return ret;
2015 }
2016
2017 /*
2018 * Enabler management.
2019 */
2020 static
2021 int lttng_match_enabler_star_glob(const char *desc_name,
2022 const char *pattern)
2023 {
2024 if (!strutils_star_glob_match(pattern, LTTNG_SIZE_MAX,
2025 desc_name, LTTNG_SIZE_MAX))
2026 return 0;
2027 return 1;
2028 }
2029
2030 static
2031 int lttng_match_enabler_name(const char *desc_name,
2032 const char *name)
2033 {
2034 if (strcmp(desc_name, name))
2035 return 0;
2036 return 1;
2037 }
2038
2039 static
2040 int lttng_desc_match_enabler_check(const struct lttng_kernel_event_desc *desc,
2041 struct lttng_event_enabler_common *enabler)
2042 {
2043 const char *desc_name, *enabler_name;
2044 bool compat = false, entry = false;
2045
2046 enabler_name = enabler->event_param.name;
2047 switch (enabler->event_param.instrumentation) {
2048 case LTTNG_KERNEL_ABI_TRACEPOINT:
2049 desc_name = desc->event_name;
2050 switch (enabler->format_type) {
2051 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2052 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2053 case LTTNG_ENABLER_FORMAT_NAME:
2054 return lttng_match_enabler_name(desc_name, enabler_name);
2055 default:
2056 return -EINVAL;
2057 }
2058 break;
2059
2060 case LTTNG_KERNEL_ABI_SYSCALL:
2061 desc_name = desc->event_name;
2062 if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
2063 desc_name += strlen("compat_");
2064 compat = true;
2065 }
2066 if (!strncmp(desc_name, "syscall_exit_",
2067 strlen("syscall_exit_"))) {
2068 desc_name += strlen("syscall_exit_");
2069 } else if (!strncmp(desc_name, "syscall_entry_",
2070 strlen("syscall_entry_"))) {
2071 desc_name += strlen("syscall_entry_");
2072 entry = true;
2073 } else {
2074 WARN_ON_ONCE(1);
2075 return -EINVAL;
2076 }
2077 switch (enabler->event_param.u.syscall.entryexit) {
2078 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
2079 break;
2080 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
2081 if (!entry)
2082 return 0;
2083 break;
2084 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
2085 if (entry)
2086 return 0;
2087 break;
2088 default:
2089 return -EINVAL;
2090 }
2091 switch (enabler->event_param.u.syscall.abi) {
2092 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
2093 break;
2094 case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
2095 if (compat)
2096 return 0;
2097 break;
2098 case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
2099 if (!compat)
2100 return 0;
2101 break;
2102 default:
2103 return -EINVAL;
2104 }
2105 switch (enabler->event_param.u.syscall.match) {
2106 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
2107 switch (enabler->format_type) {
2108 case LTTNG_ENABLER_FORMAT_STAR_GLOB:
2109 return lttng_match_enabler_star_glob(desc_name, enabler_name);
2110 case LTTNG_ENABLER_FORMAT_NAME:
2111 return lttng_match_enabler_name(desc_name, enabler_name);
2112 default:
2113 return -EINVAL;
2114 }
2115 break;
2116 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NR:
2117 return -EINVAL; /* Not implemented. */
2118 default:
2119 return -EINVAL;
2120 }
2121 break;
2122
2123 default:
2124 WARN_ON_ONCE(1);
2125 return -EINVAL;
2126 }
2127 }
2128
2129 bool lttng_desc_match_enabler(const struct lttng_kernel_event_desc *desc,
2130 struct lttng_event_enabler_common *enabler)
2131 {
2132 int ret;
2133
2134 ret = lttng_desc_match_enabler_check(desc, enabler);
2135 if (ret < 0) {
2136 WARN_ON_ONCE(1);
2137 return false;
2138 }
2139 return ret;
2140 }
2141
2142 bool lttng_event_enabler_match_event(struct lttng_event_enabler_common *event_enabler,
2143 struct lttng_kernel_event_common *event)
2144 {
2145 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2146 return false;
2147
2148 switch (event_enabler->enabler_type) {
2149 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2150 {
2151 struct lttng_event_recorder_enabler *event_recorder_enabler =
2152 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2153 struct lttng_kernel_event_recorder *event_recorder =
2154 container_of(event, struct lttng_kernel_event_recorder, parent);
2155
2156 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
2157 && event_recorder->chan == event_recorder_enabler->chan)
2158 return true;
2159 else
2160 return false;
2161 }
2162 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2163 {
2164 struct lttng_event_notifier_enabler *event_notifier_enabler =
2165 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2166 struct lttng_kernel_event_notifier *event_notifier =
2167 container_of(event, struct lttng_kernel_event_notifier, parent);
2168
2169 if (lttng_desc_match_enabler(event->priv->desc, event_enabler)
2170 && event_notifier->priv->group == event_notifier_enabler->group
2171 && event->priv->user_token == event_enabler->user_token)
2172 return true;
2173 else
2174 return false;
2175 }
2176 default:
2177 WARN_ON_ONCE(1);
2178 return false;
2179 }
2180 }
2181
2182 bool lttng_event_enabler_desc_match_event(struct lttng_event_enabler_common *event_enabler,
2183 const struct lttng_kernel_event_desc *desc,
2184 struct lttng_kernel_event_common *event)
2185 {
2186 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2187 return false;
2188
2189 switch (event_enabler->enabler_type) {
2190 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2191 {
2192 struct lttng_event_recorder_enabler *event_recorder_enabler =
2193 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2194 struct lttng_kernel_event_recorder *event_recorder =
2195 container_of(event, struct lttng_kernel_event_recorder, parent);
2196
2197 if (event->priv->desc == desc && event_recorder->chan == event_recorder_enabler->chan)
2198 return true;
2199 else
2200 return false;
2201 }
2202 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2203 {
2204 struct lttng_event_notifier_enabler *event_notifier_enabler =
2205 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2206 struct lttng_kernel_event_notifier *event_notifier =
2207 container_of(event, struct lttng_kernel_event_notifier, parent);
2208
2209 if (event->priv->desc == desc
2210 && event_notifier->priv->group == event_notifier_enabler->group
2211 && event->priv->user_token == event_enabler->user_token)
2212 return true;
2213 else
2214 return false;
2215 }
2216 default:
2217 WARN_ON_ONCE(1);
2218 return false;
2219 }
2220 }
2221
2222 bool lttng_event_enabler_event_name_match_event(struct lttng_event_enabler_common *event_enabler,
2223 const char *event_name,
2224 struct lttng_kernel_event_common *event)
2225 {
2226 if (event_enabler->event_param.instrumentation != event->priv->instrumentation)
2227 return false;
2228
2229 switch (event_enabler->enabler_type) {
2230 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2231 {
2232 struct lttng_event_recorder_enabler *event_recorder_enabler =
2233 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2234 struct lttng_kernel_event_recorder *event_recorder =
2235 container_of(event, struct lttng_kernel_event_recorder, parent);
2236
2237 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2238 && event_recorder->chan == event_recorder_enabler->chan)
2239 return true;
2240 else
2241 return false;
2242 }
2243 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2244 {
2245 struct lttng_event_notifier_enabler *event_notifier_enabler =
2246 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2247 struct lttng_kernel_event_notifier *event_notifier =
2248 container_of(event, struct lttng_kernel_event_notifier, parent);
2249
2250 if (!strncmp(event->priv->desc->event_name, event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
2251 && event_notifier->priv->group == event_notifier_enabler->group
2252 && event->priv->user_token == event_enabler->user_token)
2253 return true;
2254 else
2255 return false;
2256 }
2257 default:
2258 WARN_ON_ONCE(1);
2259 return false;
2260 }
2261 }
2262
2263 static
2264 struct lttng_enabler_ref *lttng_enabler_ref(
2265 struct list_head *enablers_ref_list,
2266 struct lttng_event_enabler_common *enabler)
2267 {
2268 struct lttng_enabler_ref *enabler_ref;
2269
2270 list_for_each_entry(enabler_ref, enablers_ref_list, node) {
2271 if (enabler_ref->ref == enabler)
2272 return enabler_ref;
2273 }
2274 return NULL;
2275 }
2276
2277 static
2278 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler_common *event_enabler)
2279 {
2280 struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(event_enabler);
2281 struct lttng_kernel_probe_desc *probe_desc;
2282 const struct lttng_kernel_event_desc *desc;
2283 struct list_head *probe_list;
2284 int i;
2285
2286 probe_list = lttng_get_probe_list_head();
2287 /*
2288 * For each probe event, if we find that a probe event matches
2289 * our enabler, create an associated lttng_event if not
2290 * already present.
2291 */
2292 list_for_each_entry(probe_desc, probe_list, head) {
2293 for (i = 0; i < probe_desc->nr_events; i++) {
2294 int found = 0;
2295 struct hlist_head *head;
2296 struct lttng_kernel_event_common *event;
2297 struct lttng_kernel_event_common_private *event_priv;
2298
2299 desc = probe_desc->event_desc[i];
2300 if (!lttng_desc_match_enabler(desc, event_enabler))
2301 continue;
2302
2303 /*
2304 * Check if already created.
2305 */
2306 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
2307 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
2308 if (lttng_event_enabler_desc_match_event(event_enabler, desc, event_priv->pub))
2309 found = 1;
2310 }
2311 if (found)
2312 continue;
2313
2314 /*
2315 * We need to create an event for this event probe.
2316 */
2317 event = _lttng_kernel_event_create(event_enabler, desc);
2318 if (!event) {
2319 printk(KERN_INFO "LTTng: Unable to create event %s\n",
2320 probe_desc->event_desc[i]->event_name);
2321 }
2322 }
2323 }
2324 }
2325
2326 static
2327 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler_common *event_enabler)
2328 {
2329 int ret;
2330
2331 ret = lttng_syscalls_register_event(event_enabler);
2332 WARN_ON_ONCE(ret);
2333 }
2334
2335 /*
2336 * Create event if it is missing and present in the list of tracepoint probes.
2337 * Should be called with sessions mutex held.
2338 */
2339 static
2340 void lttng_create_event_if_missing(struct lttng_event_enabler_common *event_enabler)
2341 {
2342 switch (event_enabler->event_param.instrumentation) {
2343 case LTTNG_KERNEL_ABI_TRACEPOINT:
2344 lttng_create_tracepoint_event_if_missing(event_enabler);
2345 break;
2346
2347 case LTTNG_KERNEL_ABI_SYSCALL:
2348 lttng_create_syscall_event_if_missing(event_enabler);
2349 break;
2350
2351 default:
2352 WARN_ON_ONCE(1);
2353 break;
2354 }
2355 }
2356
2357 static
2358 void lttng_event_enabler_init_event_filter(struct lttng_event_enabler_common *event_enabler,
2359 struct lttng_kernel_event_common *event)
2360 {
2361 /* Link filter bytecodes if not linked yet. */
2362 lttng_enabler_link_bytecode(event->priv->desc, lttng_static_ctx,
2363 &event->priv->filter_bytecode_runtime_head, &event_enabler->filter_bytecode_head);
2364 }
2365
2366 static
2367 void lttng_event_enabler_init_event_capture(struct lttng_event_enabler_common *event_enabler,
2368 struct lttng_kernel_event_common *event)
2369 {
2370 switch (event_enabler->enabler_type) {
2371 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2372 break;
2373 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2374 {
2375 struct lttng_event_notifier_enabler *event_notifier_enabler =
2376 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2377 struct lttng_kernel_event_notifier *event_notifier =
2378 container_of(event, struct lttng_kernel_event_notifier, parent);
2379
2380 /* Link capture bytecodes if not linked yet. */
2381 lttng_enabler_link_bytecode(event->priv->desc,
2382 lttng_static_ctx, &event_notifier->priv->capture_bytecode_runtime_head,
2383 &event_notifier_enabler->capture_bytecode_head);
2384 event_notifier->priv->num_captures = event_notifier_enabler->num_captures;
2385 break;
2386 }
2387 default:
2388 WARN_ON_ONCE(1);
2389 }
2390 }
2391
2392 /*
2393 * Create events associated with an event_enabler (if not already present),
2394 * and add backward reference from the event to the enabler.
2395 * Should be called with sessions mutex held.
2396 */
2397 static
2398 int lttng_event_enabler_ref_events(struct lttng_event_enabler_common *event_enabler)
2399 {
2400 struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(event_enabler);
2401 struct lttng_kernel_event_common_private *event_priv;
2402
2403 lttng_syscall_table_set_wildcard_all(event_enabler);
2404
2405 /* First ensure that probe events are created for this enabler. */
2406 lttng_create_event_if_missing(event_enabler);
2407
2408 /* Link the created event with its associated enabler. */
2409 list_for_each_entry(event_priv, event_list_head, node) {
2410 struct lttng_kernel_event_common *event = event_priv->pub;
2411 struct lttng_enabler_ref *enabler_ref;
2412
2413 if (!lttng_event_enabler_match_event(event_enabler, event))
2414 continue;
2415
2416 enabler_ref = lttng_enabler_ref(&event_priv->enablers_ref_head, event_enabler);
2417 if (!enabler_ref) {
2418 /*
2419 * If no backward ref, create it.
2420 * Add backward ref from event_notifier to enabler.
2421 */
2422 enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
2423 if (!enabler_ref)
2424 return -ENOMEM;
2425
2426 enabler_ref->ref = event_enabler;
2427 list_add(&enabler_ref->node, &event_priv->enablers_ref_head);
2428 }
2429
2430 lttng_event_enabler_init_event_filter(event_enabler, event);
2431 lttng_event_enabler_init_event_capture(event_enabler, event);
2432 }
2433 return 0;
2434 }
2435
2436 /*
2437 * Called at module load: connect the probe on all enablers matching
2438 * this event.
2439 * Called with sessions lock held.
2440 */
2441 int lttng_fix_pending_events(void)
2442 {
2443 struct lttng_kernel_session_private *session_priv;
2444
2445 list_for_each_entry(session_priv, &sessions, list)
2446 lttng_session_lazy_sync_event_enablers(session_priv->pub);
2447 return 0;
2448 }
2449
2450 static bool lttng_event_notifier_group_has_active_event_notifiers(
2451 struct lttng_event_notifier_group *event_notifier_group)
2452 {
2453 struct lttng_event_enabler_common *event_enabler;
2454
2455 list_for_each_entry(event_enabler, &event_notifier_group->enablers_head, node) {
2456 if (event_enabler->enabled)
2457 return true;
2458 }
2459 return false;
2460 }
2461
2462 bool lttng_event_notifier_active(void)
2463 {
2464 struct lttng_event_notifier_group *event_notifier_group;
2465
2466 list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
2467 if (lttng_event_notifier_group_has_active_event_notifiers(event_notifier_group))
2468 return true;
2469 }
2470 return false;
2471 }
2472
2473 int lttng_fix_pending_event_notifiers(void)
2474 {
2475 struct lttng_event_notifier_group *event_notifier_group;
2476
2477 list_for_each_entry(event_notifier_group, &event_notifier_groups, node)
2478 lttng_event_notifier_group_sync_enablers(event_notifier_group);
2479 return 0;
2480 }
2481
2482 struct lttng_event_recorder_enabler *lttng_event_recorder_enabler_create(
2483 enum lttng_enabler_format_type format_type,
2484 struct lttng_kernel_abi_event *event_param,
2485 struct lttng_kernel_channel_buffer *chan)
2486 {
2487 struct lttng_event_recorder_enabler *event_enabler;
2488
2489 event_enabler = kzalloc(sizeof(*event_enabler), GFP_KERNEL);
2490 if (!event_enabler)
2491 return NULL;
2492 event_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_RECORDER;
2493 event_enabler->parent.format_type = format_type;
2494 INIT_LIST_HEAD(&event_enabler->parent.filter_bytecode_head);
2495 memcpy(&event_enabler->parent.event_param, event_param,
2496 sizeof(event_enabler->parent.event_param));
2497 event_enabler->chan = chan;
2498 /* ctx left NULL */
2499 event_enabler->parent.enabled = 0;
2500 return event_enabler;
2501 }
2502
2503 void lttng_event_enabler_session_add(struct lttng_kernel_session *session,
2504 struct lttng_event_recorder_enabler *event_enabler)
2505 {
2506 mutex_lock(&sessions_mutex);
2507 list_add(&event_enabler->parent.node, &session->priv->enablers_head);
2508 event_enabler->parent.published = true;
2509 lttng_session_lazy_sync_event_enablers(session);
2510 mutex_unlock(&sessions_mutex);
2511 }
2512
2513 int lttng_event_enabler_enable(struct lttng_event_enabler_common *event_enabler)
2514 {
2515 mutex_lock(&sessions_mutex);
2516 event_enabler->enabled = 1;
2517 lttng_event_enabler_sync(event_enabler);
2518 mutex_unlock(&sessions_mutex);
2519 return 0;
2520 }
2521
2522 int lttng_event_enabler_disable(struct lttng_event_enabler_common *event_enabler)
2523 {
2524 mutex_lock(&sessions_mutex);
2525 event_enabler->enabled = 0;
2526 lttng_event_enabler_sync(event_enabler);
2527 mutex_unlock(&sessions_mutex);
2528 return 0;
2529 }
2530
2531 static
2532 int lttng_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *enabler,
2533 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2534 {
2535 struct lttng_kernel_bytecode_node *bytecode_node;
2536 uint32_t bytecode_len;
2537 int ret;
2538
2539 ret = get_user(bytecode_len, &bytecode->len);
2540 if (ret)
2541 return ret;
2542 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2543 GFP_KERNEL);
2544 if (!bytecode_node)
2545 return -ENOMEM;
2546 ret = copy_from_user(&bytecode_node->bc, bytecode,
2547 sizeof(*bytecode) + bytecode_len);
2548 if (ret)
2549 goto error_free;
2550
2551 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_FILTER;
2552 bytecode_node->enabler = enabler;
2553 /* Enforce length based on allocated size */
2554 bytecode_node->bc.len = bytecode_len;
2555 list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
2556
2557 return 0;
2558
2559 error_free:
2560 lttng_kvfree(bytecode_node);
2561 return ret;
2562 }
2563
2564 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler_common *event_enabler,
2565 struct lttng_kernel_abi_filter_bytecode __user *bytecode)
2566 {
2567 int ret;
2568 ret = lttng_enabler_attach_filter_bytecode(event_enabler, bytecode);
2569 if (ret)
2570 goto error;
2571 lttng_event_enabler_sync(event_enabler);
2572 return 0;
2573
2574 error:
2575 return ret;
2576 }
2577
2578 int lttng_event_add_callsite(struct lttng_kernel_event_common *event,
2579 struct lttng_kernel_abi_event_callsite __user *callsite)
2580 {
2581
2582 switch (event->priv->instrumentation) {
2583 case LTTNG_KERNEL_ABI_UPROBE:
2584 return lttng_uprobes_event_add_callsite(event, callsite);
2585 default:
2586 return -EINVAL;
2587 }
2588 }
2589
2590 static
2591 void lttng_enabler_destroy(struct lttng_event_enabler_common *enabler)
2592 {
2593 struct lttng_kernel_bytecode_node *filter_node, *tmp_filter_node;
2594
2595 /* Destroy filter bytecode */
2596 list_for_each_entry_safe(filter_node, tmp_filter_node,
2597 &enabler->filter_bytecode_head, node) {
2598 lttng_kvfree(filter_node);
2599 }
2600 }
2601
2602 void lttng_event_enabler_destroy(struct lttng_event_enabler_common *event_enabler)
2603 {
2604 lttng_enabler_destroy(event_enabler);
2605 if (event_enabler->published)
2606 list_del(&event_enabler->node);
2607
2608 switch (event_enabler->enabler_type) {
2609 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2610 {
2611 struct lttng_event_recorder_enabler *event_recorder_enabler =
2612 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2613
2614 kfree(event_recorder_enabler);
2615 break;
2616 }
2617 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2618 {
2619 struct lttng_event_notifier_enabler *event_notifier_enabler =
2620 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2621
2622 kfree(event_notifier_enabler);
2623 break;
2624 }
2625 default:
2626 WARN_ON_ONCE(1);
2627 }
2628 }
2629
2630 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
2631 enum lttng_enabler_format_type format_type,
2632 struct lttng_kernel_abi_event_notifier *event_notifier_param,
2633 struct lttng_event_notifier_group *event_notifier_group)
2634 {
2635 struct lttng_event_notifier_enabler *event_notifier_enabler;
2636
2637 event_notifier_enabler = kzalloc(sizeof(*event_notifier_enabler), GFP_KERNEL);
2638 if (!event_notifier_enabler)
2639 return NULL;
2640
2641 event_notifier_enabler->parent.enabler_type = LTTNG_EVENT_ENABLER_TYPE_NOTIFIER;
2642 event_notifier_enabler->parent.format_type = format_type;
2643 INIT_LIST_HEAD(&event_notifier_enabler->parent.filter_bytecode_head);
2644 INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
2645
2646 event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
2647 event_notifier_enabler->num_captures = 0;
2648
2649 memcpy(&event_notifier_enabler->parent.event_param, &event_notifier_param->event,
2650 sizeof(event_notifier_enabler->parent.event_param));
2651
2652 event_notifier_enabler->parent.enabled = 0;
2653 event_notifier_enabler->parent.user_token = event_notifier_param->event.token;
2654 event_notifier_enabler->group = event_notifier_group;
2655 return event_notifier_enabler;
2656 }
2657
2658 void lttng_event_notifier_enabler_group_add(struct lttng_event_notifier_group *event_notifier_group,
2659 struct lttng_event_notifier_enabler *event_notifier_enabler)
2660 {
2661 mutex_lock(&sessions_mutex);
2662 list_add(&event_notifier_enabler->parent.node, &event_notifier_enabler->group->enablers_head);
2663 event_notifier_enabler->parent.published = true;
2664 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2665 mutex_unlock(&sessions_mutex);
2666 }
2667
2668 int lttng_event_notifier_enabler_enable(
2669 struct lttng_event_notifier_enabler *event_notifier_enabler)
2670 {
2671 mutex_lock(&sessions_mutex);
2672 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
2673 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2674 mutex_unlock(&sessions_mutex);
2675 return 0;
2676 }
2677
2678 int lttng_event_notifier_enabler_disable(
2679 struct lttng_event_notifier_enabler *event_notifier_enabler)
2680 {
2681 mutex_lock(&sessions_mutex);
2682 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
2683 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2684 mutex_unlock(&sessions_mutex);
2685 return 0;
2686 }
2687
2688 int lttng_event_notifier_enabler_attach_capture_bytecode(
2689 struct lttng_event_notifier_enabler *event_notifier_enabler,
2690 struct lttng_kernel_abi_capture_bytecode __user *bytecode)
2691 {
2692 struct lttng_kernel_bytecode_node *bytecode_node;
2693 struct lttng_event_enabler_common *enabler =
2694 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
2695 uint32_t bytecode_len;
2696 int ret;
2697
2698 ret = get_user(bytecode_len, &bytecode->len);
2699 if (ret)
2700 return ret;
2701
2702 bytecode_node = lttng_kvzalloc(sizeof(*bytecode_node) + bytecode_len,
2703 GFP_KERNEL);
2704 if (!bytecode_node)
2705 return -ENOMEM;
2706
2707 ret = copy_from_user(&bytecode_node->bc, bytecode,
2708 sizeof(*bytecode) + bytecode_len);
2709 if (ret)
2710 goto error_free;
2711
2712 bytecode_node->type = LTTNG_KERNEL_BYTECODE_TYPE_CAPTURE;
2713 bytecode_node->enabler = enabler;
2714
2715 /* Enforce length based on allocated size */
2716 bytecode_node->bc.len = bytecode_len;
2717 list_add_tail(&bytecode_node->node, &event_notifier_enabler->capture_bytecode_head);
2718
2719 event_notifier_enabler->num_captures++;
2720
2721 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2722 goto end;
2723
2724 error_free:
2725 lttng_kvfree(bytecode_node);
2726 end:
2727 return ret;
2728 }
2729
2730 static
2731 void lttng_event_sync_filter_state(struct lttng_kernel_event_common *event)
2732 {
2733 int has_enablers_without_filter_bytecode = 0, nr_filters = 0;
2734 struct lttng_kernel_bytecode_runtime *runtime;
2735 struct lttng_enabler_ref *enabler_ref;
2736
2737 /* Check if has enablers without bytecode enabled */
2738 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2739 if (enabler_ref->ref->enabled
2740 && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
2741 has_enablers_without_filter_bytecode = 1;
2742 break;
2743 }
2744 }
2745 event->priv->has_enablers_without_filter_bytecode = has_enablers_without_filter_bytecode;
2746
2747 /* Enable filters */
2748 list_for_each_entry(runtime, &event->priv->filter_bytecode_runtime_head, node) {
2749 lttng_bytecode_sync_state(runtime);
2750 nr_filters++;
2751 }
2752 WRITE_ONCE(event->eval_filter, !(has_enablers_without_filter_bytecode || !nr_filters));
2753 }
2754
2755 static
2756 void lttng_event_sync_capture_state(struct lttng_kernel_event_common *event)
2757 {
2758 switch (event->type) {
2759 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2760 break;
2761 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2762 {
2763 struct lttng_kernel_event_notifier *event_notifier =
2764 container_of(event, struct lttng_kernel_event_notifier, parent);
2765 struct lttng_kernel_bytecode_runtime *runtime;
2766 int nr_captures = 0;
2767
2768 /* Enable captures */
2769 list_for_each_entry(runtime, &event_notifier->priv->capture_bytecode_runtime_head, node) {
2770 lttng_bytecode_sync_state(runtime);
2771 nr_captures++;
2772 }
2773 WRITE_ONCE(event_notifier->eval_capture, !!nr_captures);
2774 break;
2775 }
2776 default:
2777 WARN_ON_ONCE(1);
2778 }
2779 }
2780
2781 static
2782 bool lttng_get_event_enabled_state(struct lttng_kernel_event_common *event)
2783 {
2784 struct lttng_enabler_ref *enabler_ref;
2785 bool enabled = false;
2786
2787 switch (event->priv->instrumentation) {
2788 case LTTNG_KERNEL_ABI_TRACEPOINT:
2789 lttng_fallthrough;
2790 case LTTNG_KERNEL_ABI_SYSCALL:
2791 /* Enable events */
2792 list_for_each_entry(enabler_ref, &event->priv->enablers_ref_head, node) {
2793 if (enabler_ref->ref->enabled) {
2794 enabled = true;
2795 break;
2796 }
2797 }
2798 break;
2799 default:
2800 WARN_ON_ONCE(1);
2801 return false;
2802 }
2803
2804 switch (event->type) {
2805 case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
2806 {
2807 struct lttng_kernel_event_recorder *event_recorder =
2808 container_of(event, struct lttng_kernel_event_recorder, parent);
2809
2810 /*
2811 * Enabled state is based on union of enablers, with
2812 * intersection of session and channel transient enable
2813 * states.
2814 */
2815 return enabled && event_recorder->chan->parent.session->priv->tstate && event_recorder->chan->priv->parent.tstate;
2816 }
2817 case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
2818 return enabled;
2819 default:
2820 WARN_ON_ONCE(1);
2821 return false;
2822 }
2823 }
2824
2825 static
2826 bool lttng_event_is_lazy_sync(struct lttng_kernel_event_common *event)
2827 {
2828 switch (event->priv->instrumentation) {
2829 case LTTNG_KERNEL_ABI_TRACEPOINT:
2830 lttng_fallthrough;
2831 case LTTNG_KERNEL_ABI_SYSCALL:
2832 return true;
2833
2834 default:
2835 /* Not handled with lazy sync. */
2836 return false;
2837 }
2838 }
2839
2840 /*
2841 * Should be called with sessions mutex held.
2842 */
2843 static
2844 void lttng_sync_event_list(struct list_head *event_enabler_list,
2845 struct list_head *event_list)
2846 {
2847 struct lttng_kernel_event_common_private *event_priv;
2848 struct lttng_event_enabler_common *event_enabler;
2849
2850 list_for_each_entry(event_enabler, event_enabler_list, node)
2851 lttng_event_enabler_ref_events(event_enabler);
2852
2853 /*
2854 * For each event, if at least one of its enablers is enabled,
2855 * and its channel and session transient states are enabled, we
2856 * enable the event, else we disable it.
2857 */
2858 list_for_each_entry(event_priv, event_list, node) {
2859 struct lttng_kernel_event_common *event = event_priv->pub;
2860 bool enabled;
2861
2862 if (!lttng_event_is_lazy_sync(event))
2863 continue;
2864
2865 enabled = lttng_get_event_enabled_state(event);
2866 WRITE_ONCE(event->enabled, enabled);
2867 /*
2868 * Sync tracepoint registration with event enabled state.
2869 */
2870 if (enabled) {
2871 register_event(event);
2872 } else {
2873 _lttng_event_unregister(event);
2874 }
2875
2876 lttng_event_sync_filter_state(event);
2877 lttng_event_sync_capture_state(event);
2878 }
2879 }
2880
2881 /*
2882 * lttng_session_sync_event_enablers should be called just before starting a
2883 * session.
2884 */
2885 static
2886 void lttng_session_sync_event_enablers(struct lttng_kernel_session *session)
2887 {
2888 lttng_sync_event_list(&session->priv->enablers_head, &session->priv->events);
2889 }
2890
2891 /*
2892 * Apply enablers to session events, adding events to session if need
2893 * be. It is required after each modification applied to an active
2894 * session, and right before session "start".
2895 * "lazy" sync means we only sync if required.
2896 * Should be called with sessions mutex held.
2897 */
2898 static
2899 void lttng_session_lazy_sync_event_enablers(struct lttng_kernel_session *session)
2900 {
2901 /* We can skip if session is not active */
2902 if (!session->active)
2903 return;
2904 lttng_session_sync_event_enablers(session);
2905 }
2906
2907 static
2908 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
2909 {
2910 lttng_sync_event_list(&event_notifier_group->enablers_head, &event_notifier_group->event_notifiers_head);
2911 }
2912
2913 static
2914 void lttng_event_enabler_sync(struct lttng_event_enabler_common *event_enabler)
2915 {
2916 switch (event_enabler->enabler_type) {
2917 case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
2918 {
2919 struct lttng_event_recorder_enabler *event_recorder_enabler =
2920 container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
2921 lttng_session_lazy_sync_event_enablers(event_recorder_enabler->chan->parent.session);
2922 break;
2923 }
2924 case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
2925 {
2926 struct lttng_event_notifier_enabler *event_notifier_enabler =
2927 container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
2928 lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
2929 break;
2930 }
2931 default:
2932 WARN_ON_ONCE(1);
2933 }
2934 }
2935
2936 /*
2937 * Serialize at most one packet worth of metadata into a metadata
2938 * channel.
2939 * We grab the metadata cache mutex to get exclusive access to our metadata
2940 * buffer and to the metadata cache. Exclusive access to the metadata buffer
2941 * allows us to do racy operations such as looking for remaining space left in
2942 * packet and write, since mutual exclusion protects us from concurrent writes.
2943 * Mutual exclusion on the metadata cache allow us to read the cache content
2944 * without racing against reallocation of the cache by updates.
2945 * Returns the number of bytes written in the channel, 0 if no data
2946 * was written and a negative value on error.
2947 */
2948 int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
2949 struct lttng_kernel_ring_buffer_channel *chan, bool *coherent)
2950 {
2951 struct lttng_kernel_ring_buffer_ctx ctx;
2952 int ret = 0;
2953 size_t len, reserve_len;
2954
2955 /*
2956 * Ensure we support mutiple get_next / put sequences followed by
2957 * put_next. The metadata cache lock protects reading the metadata
2958 * cache. It can indeed be read concurrently by "get_next_subbuf" and
2959 * "flush" operations on the buffer invoked by different processes.
2960 * Moreover, since the metadata cache memory can be reallocated, we
2961 * need to have exclusive access against updates even though we only
2962 * read it.
2963 */
2964 mutex_lock(&stream->metadata_cache->lock);
2965 WARN_ON(stream->metadata_in < stream->metadata_out);
2966 if (stream->metadata_in != stream->metadata_out)
2967 goto end;
2968
2969 /* Metadata regenerated, change the version. */
2970 if (stream->metadata_cache->version != stream->version)
2971 stream->version = stream->metadata_cache->version;
2972
2973 len = stream->metadata_cache->metadata_written -
2974 stream->metadata_in;
2975 if (!len)
2976 goto end;
2977 reserve_len = min_t(size_t,
2978 stream->transport->ops.priv->packet_avail_size(chan),
2979 len);
2980 lib_ring_buffer_ctx_init(&ctx, chan, reserve_len,
2981 sizeof(char), NULL);
2982 /*
2983 * If reservation failed, return an error to the caller.
2984 */
2985 ret = stream->transport->ops.event_reserve(&ctx);
2986 if (ret != 0) {
2987 printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
2988 stream->coherent = false;
2989 goto end;
2990 }
2991 stream->transport->ops.event_write(&ctx,
2992 stream->metadata_cache->data + stream->metadata_in,
2993 reserve_len, 1);
2994 stream->transport->ops.event_commit(&ctx);
2995 stream->metadata_in += reserve_len;
2996 if (reserve_len < len)
2997 stream->coherent = false;
2998 else
2999 stream->coherent = true;
3000 ret = reserve_len;
3001
3002 end:
3003 if (coherent)
3004 *coherent = stream->coherent;
3005 mutex_unlock(&stream->metadata_cache->lock);
3006 return ret;
3007 }
3008
3009 static
3010 void lttng_metadata_begin(struct lttng_kernel_session *session)
3011 {
3012 if (atomic_inc_return(&session->priv->metadata_cache->producing) == 1)
3013 mutex_lock(&session->priv->metadata_cache->lock);
3014 }
3015
3016 static
3017 void lttng_metadata_end(struct lttng_kernel_session *session)
3018 {
3019 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
3020 if (atomic_dec_return(&session->priv->metadata_cache->producing) == 0) {
3021 struct lttng_metadata_stream *stream;
3022
3023 list_for_each_entry(stream, &session->priv->metadata_cache->metadata_stream, list)
3024 wake_up_interruptible(&stream->read_wait);
3025 mutex_unlock(&session->priv->metadata_cache->lock);
3026 }
3027 }
3028
3029 /*
3030 * Write the metadata to the metadata cache.
3031 * Must be called with sessions_mutex held.
3032 * The metadata cache lock protects us from concurrent read access from
3033 * thread outputting metadata content to ring buffer.
3034 * The content of the printf is printed as a single atomic metadata
3035 * transaction.
3036 */
3037 int lttng_metadata_printf(struct lttng_kernel_session *session,
3038 const char *fmt, ...)
3039 {
3040 char *str;
3041 size_t len;
3042 va_list ap;
3043
3044 WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
3045
3046 va_start(ap, fmt);
3047 str = kvasprintf(GFP_KERNEL, fmt, ap);
3048 va_end(ap);
3049 if (!str)
3050 return -ENOMEM;
3051
3052 len = strlen(str);
3053 WARN_ON_ONCE(!atomic_read(&session->priv->metadata_cache->producing));
3054 if (session->priv->metadata_cache->metadata_written + len >
3055 session->priv->metadata_cache->cache_alloc) {
3056 char *tmp_cache_realloc;
3057 unsigned int tmp_cache_alloc_size;
3058
3059 tmp_cache_alloc_size = max_t(unsigned int,
3060 session->priv->metadata_cache->cache_alloc + len,
3061 session->priv->metadata_cache->cache_alloc << 1);
3062 tmp_cache_realloc = vzalloc(tmp_cache_alloc_size);
3063 if (!tmp_cache_realloc)
3064 goto err;
3065 if (session->priv->metadata_cache->data) {
3066 memcpy(tmp_cache_realloc,
3067 session->priv->metadata_cache->data,
3068 session->priv->metadata_cache->cache_alloc);
3069 vfree(session->priv->metadata_cache->data);
3070 }
3071
3072 session->priv->metadata_cache->cache_alloc = tmp_cache_alloc_size;
3073 session->priv->metadata_cache->data = tmp_cache_realloc;
3074 }
3075 memcpy(session->priv->metadata_cache->data +
3076 session->priv->metadata_cache->metadata_written,
3077 str, len);
3078 session->priv->metadata_cache->metadata_written += len;
3079 kfree(str);
3080
3081 return 0;
3082
3083 err:
3084 kfree(str);
3085 return -ENOMEM;
3086 }
3087
3088 static
3089 int print_tabs(struct lttng_kernel_session *session, size_t nesting)
3090 {
3091 size_t i;
3092
3093 for (i = 0; i < nesting; i++) {
3094 int ret;
3095
3096 ret = lttng_metadata_printf(session, " ");
3097 if (ret) {
3098 return ret;
3099 }
3100 }
3101 return 0;
3102 }
3103
3104 static
3105 int lttng_field_name_statedump(struct lttng_kernel_session *session,
3106 const struct lttng_kernel_event_field *field,
3107 size_t nesting)
3108 {
3109 return lttng_metadata_printf(session, " _%s;\n", field->name);
3110 }
3111
3112 static
3113 int _lttng_integer_type_statedump(struct lttng_kernel_session *session,
3114 const struct lttng_kernel_type_integer *type,
3115 enum lttng_kernel_string_encoding parent_encoding,
3116 size_t nesting)
3117 {
3118 int ret;
3119
3120 ret = print_tabs(session, nesting);
3121 if (ret)
3122 return ret;
3123 ret = lttng_metadata_printf(session,
3124 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
3125 type->size,
3126 type->alignment,
3127 type->signedness,
3128 (parent_encoding == lttng_kernel_string_encoding_none)
3129 ? "none"
3130 : (parent_encoding == lttng_kernel_string_encoding_UTF8)
3131 ? "UTF8"
3132 : "ASCII",
3133 type->base,
3134 #if __BYTE_ORDER == __BIG_ENDIAN
3135 type->reverse_byte_order ? " byte_order = le;" : ""
3136 #else
3137 type->reverse_byte_order ? " byte_order = be;" : ""
3138 #endif
3139 );
3140 return ret;
3141 }
3142
3143 /*
3144 * Must be called with sessions_mutex held.
3145 */
3146 static
3147 int _lttng_struct_type_statedump(struct lttng_kernel_session *session,
3148 const struct lttng_kernel_type_struct *type,
3149 size_t nesting)
3150 {
3151 const char *prev_field_name = NULL;
3152 int ret;
3153 uint32_t i, nr_fields;
3154 unsigned int alignment;
3155
3156 ret = print_tabs(session, nesting);
3157 if (ret)
3158 return ret;
3159 ret = lttng_metadata_printf(session,
3160 "struct {\n");
3161 if (ret)
3162 return ret;
3163 nr_fields = type->nr_fields;
3164 for (i = 0; i < nr_fields; i++) {
3165 const struct lttng_kernel_event_field *iter_field;
3166
3167 iter_field = type->fields[i];
3168 ret = _lttng_field_statedump(session, iter_field, nesting + 1, &prev_field_name);
3169 if (ret)
3170 return ret;
3171 }
3172 ret = print_tabs(session, nesting);
3173 if (ret)
3174 return ret;
3175 alignment = type->alignment;
3176 if (alignment) {
3177 ret = lttng_metadata_printf(session,
3178 "} align(%u)",
3179 alignment);
3180 } else {
3181 ret = lttng_metadata_printf(session,
3182 "}");
3183 }
3184 return ret;
3185 }
3186
3187 /*
3188 * Must be called with sessions_mutex held.
3189 */
3190 static
3191 int _lttng_struct_field_statedump(struct lttng_kernel_session *session,
3192 const struct lttng_kernel_event_field *field,
3193 size_t nesting)
3194 {
3195 int ret;
3196
3197 ret = _lttng_struct_type_statedump(session,
3198 lttng_kernel_get_type_struct(field->type), nesting);
3199 if (ret)
3200 return ret;
3201 return lttng_field_name_statedump(session, field, nesting);
3202 }
3203
3204 /*
3205 * Must be called with sessions_mutex held.
3206 */
3207 static
3208 int _lttng_variant_type_statedump(struct lttng_kernel_session *session,
3209 const struct lttng_kernel_type_variant *type,
3210 size_t nesting,
3211 const char *prev_field_name)
3212 {
3213 const char *tag_name;
3214 int ret;
3215 uint32_t i, nr_choices;
3216
3217 tag_name = type->tag_name;
3218 if (!tag_name)
3219 tag_name = prev_field_name;
3220 if (!tag_name)
3221 return -EINVAL;
3222 /*
3223 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
3224 */
3225 if (type->alignment != 0)
3226 return -EINVAL;
3227 ret = print_tabs(session, nesting);
3228 if (ret)
3229 return ret;
3230 ret = lttng_metadata_printf(session,
3231 "variant <_%s> {\n",
3232 tag_name);
3233 if (ret)
3234 return ret;
3235 nr_choices = type->nr_choices;
3236 for (i = 0; i < nr_choices; i++) {
3237 const struct lttng_kernel_event_field *iter_field;
3238
3239 iter_field = type->choices[i];
3240 ret = _lttng_field_statedump(session, iter_field, nesting + 1, NULL);
3241 if (ret)
3242 return ret;
3243 }
3244 ret = print_tabs(session, nesting);
3245 if (ret)
3246 return ret;
3247 ret = lttng_metadata_printf(session,
3248 "}");
3249 return ret;
3250 }
3251
3252 /*
3253 * Must be called with sessions_mutex held.
3254 */
3255 static
3256 int _lttng_variant_field_statedump(struct lttng_kernel_session *session,
3257 const struct lttng_kernel_event_field *field,
3258 size_t nesting,
3259 const char *prev_field_name)
3260 {
3261 int ret;
3262
3263 ret = _lttng_variant_type_statedump(session,
3264 lttng_kernel_get_type_variant(field->type), nesting,
3265 prev_field_name);
3266 if (ret)
3267 return ret;
3268 return lttng_field_name_statedump(session, field, nesting);
3269 }
3270
3271 /*
3272 * Must be called with sessions_mutex held.
3273 */
3274 static
3275 int _lttng_array_field_statedump(struct lttng_kernel_session *session,
3276 const struct lttng_kernel_event_field *field,
3277 size_t nesting)
3278 {
3279 int ret;
3280 const struct lttng_kernel_type_array *array_type;
3281 const struct lttng_kernel_type_common *elem_type;
3282
3283 array_type = lttng_kernel_get_type_array(field->type);
3284 WARN_ON_ONCE(!array_type);
3285
3286 if (array_type->alignment) {
3287 ret = print_tabs(session, nesting);
3288 if (ret)
3289 return ret;
3290 ret = lttng_metadata_printf(session,
3291 "struct { } align(%u) _%s_padding;\n",
3292 array_type->alignment * CHAR_BIT,
3293 field->name);
3294 if (ret)
3295 return ret;
3296 }
3297 /*
3298 * Nested compound types: Only array of structures and variants are
3299 * currently supported.
3300 */
3301 elem_type = array_type->elem_type;
3302 switch (elem_type->type) {
3303 case lttng_kernel_type_integer:
3304 case lttng_kernel_type_struct:
3305 case lttng_kernel_type_variant:
3306 ret = _lttng_type_statedump(session, elem_type,
3307 array_type->encoding, nesting);
3308 if (ret)
3309 return ret;
3310 break;
3311
3312 default:
3313 return -EINVAL;
3314 }
3315 ret = lttng_metadata_printf(session,
3316 " _%s[%u];\n",
3317 field->name,
3318 array_type->length);
3319 return ret;
3320 }
3321
3322 /*
3323 * Must be called with sessions_mutex held.
3324 */
3325 static
3326 int _lttng_sequence_field_statedump(struct lttng_kernel_session *session,
3327 const struct lttng_kernel_event_field *field,
3328 size_t nesting,
3329 const char *prev_field_name)
3330 {
3331 int ret;
3332 const char *length_name;
3333 const struct lttng_kernel_type_sequence *sequence_type;
3334 const struct lttng_kernel_type_common *elem_type;
3335
3336 sequence_type = lttng_kernel_get_type_sequence(field->type);
3337 WARN_ON_ONCE(!sequence_type);
3338
3339 length_name = sequence_type->length_name;
3340 if (!length_name)
3341 length_name = prev_field_name;
3342 if (!length_name)
3343 return -EINVAL;
3344
3345 if (sequence_type->alignment) {
3346 ret = print_tabs(session, nesting);
3347 if (ret)
3348 return ret;
3349 ret = lttng_metadata_printf(session,
3350 "struct { } align(%u) _%s_padding;\n",
3351 sequence_type->alignment * CHAR_BIT,
3352 field->name);
3353 if (ret)
3354 return ret;
3355 }
3356
3357 /*
3358 * Nested compound types: Only array of structures and variants are
3359 * currently supported.
3360 */
3361 elem_type = sequence_type->elem_type;
3362 switch (elem_type->type) {
3363 case lttng_kernel_type_integer:
3364 case lttng_kernel_type_struct:
3365 case lttng_kernel_type_variant:
3366 ret = _lttng_type_statedump(session, elem_type,
3367 sequence_type->encoding, nesting);
3368 if (ret)
3369 return ret;
3370 break;
3371
3372 default:
3373 return -EINVAL;
3374 }
3375 ret = lttng_metadata_printf(session,
3376 " _%s[ _%s ];\n",
3377 field->name,
3378 length_name);
3379 return ret;
3380 }
3381
3382 /*
3383 * Must be called with sessions_mutex held.
3384 */
3385 static
3386 int _lttng_enum_type_statedump(struct lttng_kernel_session *session,
3387 const struct lttng_kernel_type_enum *type,
3388 size_t nesting)
3389 {
3390 const struct lttng_kernel_enum_desc *enum_desc;
3391 const struct lttng_kernel_type_common *container_type;
3392 int ret;
3393 unsigned int i, nr_entries;
3394
3395 container_type = type->container_type;
3396 if (container_type->type != lttng_kernel_type_integer) {
3397 ret = -EINVAL;
3398 goto end;
3399 }
3400 enum_desc = type->desc;
3401 nr_entries = enum_desc->nr_entries;
3402
3403 ret = print_tabs(session, nesting);
3404 if (ret)
3405 goto end;
3406 ret = lttng_metadata_printf(session, "enum : ");
3407 if (ret)
3408 goto end;
3409 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(container_type),
3410 lttng_kernel_string_encoding_none, 0);
3411 if (ret)
3412 goto end;
3413 ret = lttng_metadata_printf(session, " {\n");
3414 if (ret)
3415 goto end;
3416 /* Dump all entries */
3417 for (i = 0; i < nr_entries; i++) {
3418 const struct lttng_kernel_enum_entry *entry = enum_desc->entries[i];
3419 int j, len;
3420
3421 ret = print_tabs(session, nesting + 1);
3422 if (ret)
3423 goto end;
3424 ret = lttng_metadata_printf(session,
3425 "\"");
3426 if (ret)
3427 goto end;
3428 len = strlen(entry->string);
3429 /* Escape the character '"' */
3430 for (j = 0; j < len; j++) {
3431 char c = entry->string[j];
3432
3433 switch (c) {
3434 case '"':
3435 ret = lttng_metadata_printf(session,
3436 "\\\"");
3437 break;
3438 case '\\':
3439 ret = lttng_metadata_printf(session,
3440 "\\\\");
3441 break;
3442 default:
3443 ret = lttng_metadata_printf(session,
3444 "%c", c);
3445 break;
3446 }
3447 if (ret)
3448 goto end;
3449 }
3450 ret = lttng_metadata_printf(session, "\"");
3451 if (ret)
3452 goto end;
3453
3454 if (entry->options.is_auto) {
3455 ret = lttng_metadata_printf(session, ",\n");
3456 if (ret)
3457 goto end;
3458 } else {
3459 ret = lttng_metadata_printf(session,
3460 " = ");
3461 if (ret)
3462 goto end;
3463 if (entry->start.signedness)
3464 ret = lttng_metadata_printf(session,
3465 "%lld", (long long) entry->start.value);
3466 else
3467 ret = lttng_metadata_printf(session,
3468 "%llu", entry->start.value);
3469 if (ret)
3470 goto end;
3471 if (entry->start.signedness == entry->end.signedness &&
3472 entry->start.value
3473 == entry->end.value) {
3474 ret = lttng_metadata_printf(session,
3475 ",\n");
3476 } else {
3477 if (entry->end.signedness) {
3478 ret = lttng_metadata_printf(session,
3479 " ... %lld,\n",
3480 (long long) entry->end.value);
3481 } else {
3482 ret = lttng_metadata_printf(session,
3483 " ... %llu,\n",
3484 entry->end.value);
3485 }
3486 }
3487 if (ret)
3488 goto end;
3489 }
3490 }
3491 ret = print_tabs(session, nesting);
3492 if (ret)
3493 goto end;
3494 ret = lttng_metadata_printf(session, "}");
3495 end:
3496 return ret;
3497 }
3498
3499 /*
3500 * Must be called with sessions_mutex held.
3501 */
3502 static
3503 int _lttng_enum_field_statedump(struct lttng_kernel_session *session,
3504 const struct lttng_kernel_event_field *field,
3505 size_t nesting)
3506 {
3507 int ret;
3508 const struct lttng_kernel_type_enum *enum_type;
3509
3510 enum_type = lttng_kernel_get_type_enum(field->type);
3511 WARN_ON_ONCE(!enum_type);
3512 ret = _lttng_enum_type_statedump(session, enum_type, nesting);
3513 if (ret)
3514 return ret;
3515 return lttng_field_name_statedump(session, field, nesting);
3516 }
3517
3518 static
3519 int _lttng_integer_field_statedump(struct lttng_kernel_session *session,
3520 const struct lttng_kernel_event_field *field,
3521 size_t nesting)
3522 {
3523 int ret;
3524
3525 ret = _lttng_integer_type_statedump(session, lttng_kernel_get_type_integer(field->type),
3526 lttng_kernel_string_encoding_none, nesting);
3527 if (ret)
3528 return ret;
3529 return lttng_field_name_statedump(session, field, nesting);
3530 }
3531
3532 static
3533 int _lttng_string_type_statedump(struct lttng_kernel_session *session,
3534 const struct lttng_kernel_type_string *type,
3535 size_t nesting)
3536 {
3537 int ret;
3538
3539 /* Default encoding is UTF8 */
3540 ret = print_tabs(session, nesting);
3541 if (ret)
3542 return ret;
3543 ret = lttng_metadata_printf(session,
3544 "string%s",
3545 type->encoding == lttng_kernel_string_encoding_ASCII ?
3546 " { encoding = ASCII; }" : "");
3547 return ret;
3548 }
3549
3550 static
3551 int _lttng_string_field_statedump(struct lttng_kernel_session *session,
3552 const struct lttng_kernel_event_field *field,
3553 size_t nesting)
3554 {
3555 const struct lttng_kernel_type_string *string_type;
3556 int ret;
3557
3558 string_type = lttng_kernel_get_type_string(field->type);
3559 WARN_ON_ONCE(!string_type);
3560 ret = _lttng_string_type_statedump(session, string_type, nesting);
3561 if (ret)
3562 return ret;
3563 return lttng_field_name_statedump(session, field, nesting);
3564 }
3565
3566 /*
3567 * Must be called with sessions_mutex held.
3568 */
3569 static
3570 int _lttng_type_statedump(struct lttng_kernel_session *session,
3571 const struct lttng_kernel_type_common *type,
3572 enum lttng_kernel_string_encoding parent_encoding,
3573 size_t nesting)
3574 {
3575 int ret = 0;
3576
3577 switch (type->type) {
3578 case lttng_kernel_type_integer:
3579 ret = _lttng_integer_type_statedump(session,
3580 lttng_kernel_get_type_integer(type),
3581 parent_encoding, nesting);
3582 break;
3583 case lttng_kernel_type_enum:
3584 ret = _lttng_enum_type_statedump(session,
3585 lttng_kernel_get_type_enum(type),
3586 nesting);
3587 break;
3588 case lttng_kernel_type_string:
3589 ret = _lttng_string_type_statedump(session,
3590 lttng_kernel_get_type_string(type),
3591 nesting);
3592 break;
3593 case lttng_kernel_type_struct:
3594 ret = _lttng_struct_type_statedump(session,
3595 lttng_kernel_get_type_struct(type),
3596 nesting);
3597 break;
3598 case lttng_kernel_type_variant:
3599 ret = _lttng_variant_type_statedump(session,
3600 lttng_kernel_get_type_variant(type),
3601 nesting, NULL);
3602 break;
3603
3604 /* Nested arrays and sequences are not supported yet. */
3605 case lttng_kernel_type_array:
3606 case lttng_kernel_type_sequence:
3607 default:
3608 WARN_ON_ONCE(1);
3609 return -EINVAL;
3610 }
3611 return ret;
3612 }
3613
3614 /*
3615 * Must be called with sessions_mutex held.
3616 */
3617 static
3618 int _lttng_field_statedump(struct lttng_kernel_session *session,
3619 const struct lttng_kernel_event_field *field,
3620 size_t nesting,
3621 const char **prev_field_name_p)
3622 {
3623 const char *prev_field_name = NULL;
3624 int ret = 0;
3625
3626 if (prev_field_name_p)
3627 prev_field_name = *prev_field_name_p;
3628 switch (field->type->type) {
3629 case lttng_kernel_type_integer:
3630 ret = _lttng_integer_field_statedump(session, field, nesting);
3631 break;
3632 case lttng_kernel_type_enum:
3633 ret = _lttng_enum_field_statedump(session, field, nesting);
3634 break;
3635 case lttng_kernel_type_string:
3636 ret = _lttng_string_field_statedump(session, field, nesting);
3637 break;
3638 case lttng_kernel_type_struct:
3639 ret = _lttng_struct_field_statedump(session, field, nesting);
3640 break;
3641 case lttng_kernel_type_array:
3642 ret = _lttng_array_field_statedump(session, field, nesting);
3643 break;
3644 case lttng_kernel_type_sequence:
3645 ret = _lttng_sequence_field_statedump(session, field, nesting, prev_field_name);
3646 break;
3647 case lttng_kernel_type_variant:
3648 ret = _lttng_variant_field_statedump(session, field, nesting, prev_field_name);
3649 break;
3650
3651 default:
3652 WARN_ON_ONCE(1);
3653 return -EINVAL;
3654 }
3655 if (prev_field_name_p)
3656 *prev_field_name_p = field->name;
3657 return ret;
3658 }
3659
3660 static
3661 int _lttng_context_metadata_statedump(struct lttng_kernel_session *session,
3662 struct lttng_kernel_ctx *ctx)
3663 {
3664 const char *prev_field_name = NULL;
3665 int ret = 0;
3666 int i;
3667
3668 if (!ctx)
3669 return 0;
3670 for (i = 0; i < ctx->nr_fields; i++) {
3671 const struct lttng_kernel_ctx_field *field = &ctx->fields[i];
3672
3673 ret = _lttng_field_statedump(session, field->event_field, 2, &prev_field_name);
3674 if (ret)
3675 return ret;
3676 }
3677 return ret;
3678 }
3679
3680 static
3681 int _lttng_fields_metadata_statedump(struct lttng_kernel_session *session,
3682 struct lttng_kernel_event_recorder *event_recorder)
3683 {
3684 const char *prev_field_name = NULL;
3685 const struct lttng_kernel_event_desc *desc = event_recorder->priv->parent.desc;
3686 int ret = 0;
3687 int i;
3688
3689 for (i = 0; i < desc->tp_class->nr_fields; i++) {
3690 const struct lttng_kernel_event_field *field = desc->tp_class->fields[i];
3691
3692 ret = _lttng_field_statedump(session, field, 2, &prev_field_name);
3693 if (ret)
3694 return ret;
3695 }
3696 return ret;
3697 }
3698
3699 /*
3700 * Must be called with sessions_mutex held.
3701 * The entire event metadata is printed as a single atomic metadata
3702 * transaction.
3703 */
3704 static
3705 int _lttng_event_recorder_metadata_statedump(struct lttng_kernel_event_common *event)
3706 {
3707 struct lttng_kernel_event_recorder *event_recorder;
3708 struct lttng_kernel_channel_buffer *chan;
3709 struct lttng_kernel_session *session;
3710 int ret = 0;
3711
3712 if (event->type != LTTNG_KERNEL_EVENT_TYPE_RECORDER)
3713 return 0;
3714 event_recorder = container_of(event, struct lttng_kernel_event_recorder, parent);
3715 chan = event_recorder->chan;
3716 session = chan->parent.session;
3717
3718 if (event_recorder->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3719 return 0;
3720 if (chan->priv->channel_type == METADATA_CHANNEL)
3721 return 0;
3722
3723 lttng_metadata_begin(session);
3724
3725 ret = lttng_metadata_printf(session,
3726 "event {\n"
3727 " name = \"%s\";\n"
3728 " id = %u;\n"
3729 " stream_id = %u;\n",
3730 event_recorder->priv->parent.desc->event_name,
3731 event_recorder->priv->id,
3732 event_recorder->chan->priv->id);
3733 if (ret)
3734 goto end;
3735
3736 ret = lttng_metadata_printf(session,
3737 " fields := struct {\n"
3738 );
3739 if (ret)
3740 goto end;
3741
3742 ret = _lttng_fields_metadata_statedump(session, event_recorder);
3743 if (ret)
3744 goto end;
3745
3746 /*
3747 * LTTng space reservation can only reserve multiples of the
3748 * byte size.
3749 */
3750 ret = lttng_metadata_printf(session,
3751 " };\n"
3752 "};\n\n");
3753 if (ret)
3754 goto end;
3755
3756 event_recorder->priv->metadata_dumped = 1;
3757 end:
3758 lttng_metadata_end(session);
3759 return ret;
3760
3761 }
3762
3763 /*
3764 * Must be called with sessions_mutex held.
3765 * The entire channel metadata is printed as a single atomic metadata
3766 * transaction.
3767 */
3768 static
3769 int _lttng_channel_metadata_statedump(struct lttng_kernel_session *session,
3770 struct lttng_kernel_channel_buffer *chan)
3771 {
3772 int ret = 0;
3773
3774 if (chan->priv->metadata_dumped || !LTTNG_READ_ONCE(session->active))
3775 return 0;
3776
3777 if (chan->priv->channel_type == METADATA_CHANNEL)
3778 return 0;
3779
3780 lttng_metadata_begin(session);
3781
3782 WARN_ON_ONCE(!chan->priv->header_type);
3783 ret = lttng_metadata_printf(session,
3784 "stream {\n"
3785 " id = %u;\n"
3786 " event.header := %s;\n"
3787 " packet.context := struct packet_context;\n",
3788 chan->priv->id,
3789 chan->priv->header_type == 1 ? "struct event_header_compact" :
3790 "struct event_header_large");
3791 if (ret)
3792 goto end;
3793
3794 if (chan->priv->ctx) {
3795 ret = lttng_metadata_printf(session,
3796 " event.context := struct {\n");
3797 if (ret)
3798 goto end;
3799 }
3800 ret = _lttng_context_metadata_statedump(session, chan->priv->ctx);
3801 if (ret)
3802 goto end;
3803 if (chan->priv->ctx) {
3804 ret = lttng_metadata_printf(session,
3805 " };\n");
3806 if (ret)
3807 goto end;
3808 }
3809
3810 ret = lttng_metadata_printf(session,
3811 "};\n\n");
3812
3813 chan->priv->metadata_dumped = 1;
3814 end:
3815 lttng_metadata_end(session);
3816 return ret;
3817 }
3818
3819 /*
3820 * Must be called with sessions_mutex held.
3821 */
3822 static
3823 int _lttng_stream_packet_context_declare(struct lttng_kernel_session *session)
3824 {
3825 return lttng_metadata_printf(session,
3826 "struct packet_context {\n"
3827 " uint64_clock_monotonic_t timestamp_begin;\n"
3828 " uint64_clock_monotonic_t timestamp_end;\n"
3829 " uint64_t content_size;\n"
3830 " uint64_t packet_size;\n"
3831 " uint64_t packet_seq_num;\n"
3832 " unsigned long events_discarded;\n"
3833 " uint32_t cpu_id;\n"
3834 "};\n\n"
3835 );
3836 }
3837
3838 /*
3839 * Compact header:
3840 * id: range: 0 - 30.
3841 * id 31 is reserved to indicate an extended header.
3842 *
3843 * Large header:
3844 * id: range: 0 - 65534.
3845 * id 65535 is reserved to indicate an extended header.
3846 *
3847 * Must be called with sessions_mutex held.
3848 */
3849 static
3850 int _lttng_event_header_declare(struct lttng_kernel_session *session)
3851 {
3852 return lttng_metadata_printf(session,
3853 "struct event_header_compact {\n"
3854 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
3855 " variant <id> {\n"
3856 " struct {\n"
3857 " uint27_clock_monotonic_t timestamp;\n"
3858 " } compact;\n"
3859 " struct {\n"
3860 " uint32_t id;\n"
3861 " uint64_clock_monotonic_t timestamp;\n"
3862 " } extended;\n"
3863 " } v;\n"
3864 "} align(%u);\n"
3865 "\n"
3866 "struct event_header_large {\n"
3867 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
3868 " variant <id> {\n"
3869 " struct {\n"
3870 " uint32_clock_monotonic_t timestamp;\n"
3871 " } compact;\n"
3872 " struct {\n"
3873 " uint32_t id;\n"
3874 " uint64_clock_monotonic_t timestamp;\n"
3875 " } extended;\n"
3876 " } v;\n"
3877 "} align(%u);\n\n",
3878 lttng_alignof(uint32_t) * CHAR_BIT,
3879 lttng_alignof(uint16_t) * CHAR_BIT
3880 );
3881 }
3882
3883 /*
3884 * Approximation of NTP time of day to clock monotonic correlation,
3885 * taken at start of trace.
3886 * Yes, this is only an approximation. Yes, we can (and will) do better
3887 * in future versions.
3888 * This function may return a negative offset. It may happen if the
3889 * system sets the REALTIME clock to 0 after boot.
3890 *
3891 * Use 64bit timespec on kernels that have it, this makes 32bit arch
3892 * y2038 compliant.
3893 */
3894 static
3895 int64_t measure_clock_offset(void)
3896 {
3897 uint64_t monotonic_avg, monotonic[2], realtime;
3898 uint64_t tcf = trace_clock_freq();
3899 int64_t offset;
3900 unsigned long flags;
3901 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3902 struct timespec64 rts = { 0, 0 };
3903 #else
3904 struct timespec rts = { 0, 0 };
3905 #endif
3906
3907 /* Disable interrupts to increase correlation precision. */
3908 local_irq_save(flags);
3909 monotonic[0] = trace_clock_read64();
3910 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
3911 ktime_get_real_ts64(&rts);
3912 #else
3913 getnstimeofday(&rts);
3914 #endif
3915 monotonic[1] = trace_clock_read64();
3916 local_irq_restore(flags);
3917
3918 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
3919 realtime = (uint64_t) rts.tv_sec * tcf;
3920 if (tcf == NSEC_PER_SEC) {
3921 realtime += rts.tv_nsec;
3922 } else {
3923 uint64_t n = rts.tv_nsec * tcf;
3924
3925 do_div(n, NSEC_PER_SEC);
3926 realtime += n;
3927 }
3928 offset = (int64_t) realtime - monotonic_avg;
3929 return offset;
3930 }
3931
3932 static
3933 int print_escaped_ctf_string(struct lttng_kernel_session *session, const char *string)
3934 {
3935 int ret = 0;
3936 size_t i;
3937 char cur;
3938
3939 i = 0;
3940 cur = string[i];
3941 while (cur != '\0') {
3942 switch (cur) {
3943 case '\n':
3944 ret = lttng_metadata_printf(session, "%s", "\\n");
3945 break;
3946 case '\\':
3947 case '"':
3948 ret = lttng_metadata_printf(session, "%c", '\\');
3949 if (ret)
3950 goto error;
3951 /* We still print the current char */
3952 lttng_fallthrough;
3953 default:
3954 ret = lttng_metadata_printf(session, "%c", cur);
3955 break;
3956 }
3957
3958 if (ret)
3959 goto error;
3960
3961 cur = string[++i];
3962 }
3963 error:
3964 return ret;
3965 }
3966
3967 static
3968 int print_metadata_escaped_field(struct lttng_kernel_session *session, const char *field,
3969 const char *field_value)
3970 {
3971 int ret;
3972
3973 ret = lttng_metadata_printf(session, " %s = \"", field);
3974 if (ret)
3975 goto error;
3976
3977 ret = print_escaped_ctf_string(session, field_value);
3978 if (ret)
3979 goto error;
3980
3981 ret = lttng_metadata_printf(session, "\";\n");
3982
3983 error:
3984 return ret;
3985 }
3986
3987 /*
3988 * Output metadata into this session's metadata buffers.
3989 * Must be called with sessions_mutex held.
3990 */
3991 static
3992 int _lttng_session_metadata_statedump(struct lttng_kernel_session *session)
3993 {
3994 unsigned char *uuid_c = session->priv->uuid.b;
3995 unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
3996 const char *product_uuid;
3997 struct lttng_kernel_channel_buffer_private *chan_priv;
3998 struct lttng_kernel_event_recorder_private *event_recorder_priv;
3999 int ret = 0;
4000
4001 if (!LTTNG_READ_ONCE(session->active))
4002 return 0;
4003
4004 lttng_metadata_begin(session);
4005
4006 if (session->priv->metadata_dumped)
4007 goto skip_session;
4008
4009 snprintf(uuid_s, sizeof(uuid_s),
4010 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
4011 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
4012 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
4013 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
4014 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
4015
4016 ret = lttng_metadata_printf(session,
4017 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
4018 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
4019 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
4020 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
4021 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
4022 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
4023 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
4024 "\n"
4025 "trace {\n"
4026 " major = %u;\n"
4027 " minor = %u;\n"
4028 " uuid = \"%s\";\n"
4029 " byte_order = %s;\n"
4030 " packet.header := struct {\n"
4031 " uint32_t magic;\n"
4032 " uint8_t uuid[16];\n"
4033 " uint32_t stream_id;\n"
4034 " uint64_t stream_instance_id;\n"
4035 " };\n"
4036 "};\n\n",
4037 lttng_alignof(uint8_t) * CHAR_BIT,
4038 lttng_alignof(uint16_t) * CHAR_BIT,
4039 lttng_alignof(uint32_t) * CHAR_BIT,
4040 lttng_alignof(uint64_t) * CHAR_BIT,
4041 sizeof(unsigned long) * CHAR_BIT,
4042 lttng_alignof(unsigned long) * CHAR_BIT,
4043 CTF_SPEC_MAJOR,
4044 CTF_SPEC_MINOR,
4045 uuid_s,
4046 #if __BYTE_ORDER == __BIG_ENDIAN
4047 "be"
4048 #else
4049 "le"
4050 #endif
4051 );
4052 if (ret)
4053 goto end;
4054
4055 ret = lttng_metadata_printf(session,
4056 "env {\n"
4057 " hostname = \"%s\";\n"
4058 " domain = \"kernel\";\n"
4059 " sysname = \"%s\";\n"
4060 " kernel_release = \"%s\";\n"
4061 " kernel_version = \"%s\";\n"
4062 " tracer_name = \"lttng-modules\";\n"
4063 " tracer_major = %d;\n"
4064 " tracer_minor = %d;\n"
4065 " tracer_patchlevel = %d;\n"
4066 " trace_buffering_scheme = \"global\";\n",
4067 current->nsproxy->uts_ns->name.nodename,
4068 utsname()->sysname,
4069 utsname()->release,
4070 utsname()->version,
4071 LTTNG_MODULES_MAJOR_VERSION,
4072 LTTNG_MODULES_MINOR_VERSION,
4073 LTTNG_MODULES_PATCHLEVEL_VERSION
4074 );
4075 if (ret)
4076 goto end;
4077
4078 ret = print_metadata_escaped_field(session, "trace_name", session->priv->name);
4079 if (ret)
4080 goto end;
4081 ret = print_metadata_escaped_field(session, "trace_creation_datetime",
4082 session->priv->creation_time);
4083 if (ret)
4084 goto end;
4085
4086 /* Add the product UUID to the 'env' section */
4087 product_uuid = dmi_get_system_info(DMI_PRODUCT_UUID);
4088 if (product_uuid) {
4089 ret = lttng_metadata_printf(session,
4090 " product_uuid = \"%s\";\n",
4091 product_uuid
4092 );
4093 if (ret)
4094 goto end;
4095 }
4096
4097 /* Close the 'env' section */
4098 ret = lttng_metadata_printf(session, "};\n\n");
4099 if (ret)
4100 goto end;
4101
4102 ret = lttng_metadata_printf(session,
4103 "clock {\n"
4104 " name = \"%s\";\n",
4105 trace_clock_name()
4106 );
4107 if (ret)
4108 goto end;
4109
4110 if (!trace_clock_uuid(clock_uuid_s)) {
4111 ret = lttng_metadata_printf(session,
4112 " uuid = \"%s\";\n",
4113 clock_uuid_s
4114 );
4115 if (ret)
4116 goto end;
4117 }
4118
4119 ret = lttng_metadata_printf(session,
4120 " description = \"%s\";\n"
4121 " freq = %llu; /* Frequency, in Hz */\n"
4122 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
4123 " offset = %lld;\n"
4124 "};\n\n",
4125 trace_clock_description(),
4126 (unsigned long long) trace_clock_freq(),
4127 (long long) measure_clock_offset()
4128 );
4129 if (ret)
4130 goto end;
4131
4132 ret = lttng_metadata_printf(session,
4133 "typealias integer {\n"
4134 " size = 27; align = 1; signed = false;\n"
4135 " map = clock.%s.value;\n"
4136 "} := uint27_clock_monotonic_t;\n"
4137 "\n"
4138 "typealias integer {\n"
4139 " size = 32; align = %u; signed = false;\n"
4140 " map = clock.%s.value;\n"
4141 "} := uint32_clock_monotonic_t;\n"
4142 "\n"
4143 "typealias integer {\n"
4144 " size = 64; align = %u; signed = false;\n"
4145 " map = clock.%s.value;\n"
4146 "} := uint64_clock_monotonic_t;\n\n",
4147 trace_clock_name(),
4148 lttng_alignof(uint32_t) * CHAR_BIT,
4149 trace_clock_name(),
4150 lttng_alignof(uint64_t) * CHAR_BIT,
4151 trace_clock_name()
4152 );
4153 if (ret)
4154 goto end;
4155
4156 ret = _lttng_stream_packet_context_declare(session);
4157 if (ret)
4158 goto end;
4159
4160 ret = _lttng_event_header_declare(session);
4161 if (ret)
4162 goto end;
4163
4164 skip_session:
4165 list_for_each_entry(chan_priv, &session->priv->chan, node) {
4166 ret = _lttng_channel_metadata_statedump(session, chan_priv->pub);
4167 if (ret)
4168 goto end;
4169 }
4170
4171 list_for_each_entry(event_recorder_priv, &session->priv->events, parent.node) {
4172 ret = _lttng_event_recorder_metadata_statedump(&event_recorder_priv->pub->parent);
4173 if (ret)
4174 goto end;
4175 }
4176 session->priv->metadata_dumped = 1;
4177 end:
4178 lttng_metadata_end(session);
4179 return ret;
4180 }
4181
4182 /**
4183 * lttng_transport_register - LTT transport registration
4184 * @transport: transport structure
4185 *
4186 * Registers a transport which can be used as output to extract the data out of
4187 * LTTng. The module calling this registration function must ensure that no
4188 * trap-inducing code will be executed by the transport functions. E.g.
4189 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
4190 * is made visible to the transport function. This registration acts as a
4191 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
4192 * after its registration must it synchronize the TLBs.
4193 */
4194 void lttng_transport_register(struct lttng_transport *transport)
4195 {
4196 /*
4197 * Make sure no page fault can be triggered by the module about to be
4198 * registered. We deal with this here so we don't have to call
4199 * vmalloc_sync_mappings() in each module's init.
4200 */
4201 wrapper_vmalloc_sync_mappings();
4202
4203 mutex_lock(&sessions_mutex);
4204 list_add_tail(&transport->node, &lttng_transport_list);
4205 mutex_unlock(&sessions_mutex);
4206 }
4207 EXPORT_SYMBOL_GPL(lttng_transport_register);
4208
4209 /**
4210 * lttng_transport_unregister - LTT transport unregistration
4211 * @transport: transport structure
4212 */
4213 void lttng_transport_unregister(struct lttng_transport *transport)
4214 {
4215 mutex_lock(&sessions_mutex);
4216 list_del(&transport->node);
4217 mutex_unlock(&sessions_mutex);
4218 }
4219 EXPORT_SYMBOL_GPL(lttng_transport_unregister);
4220
4221 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
4222 {
4223 /*
4224 * Make sure no page fault can be triggered by the module about to be
4225 * registered. We deal with this here so we don't have to call
4226 * vmalloc_sync_mappings() in each module's init.
4227 */
4228 wrapper_vmalloc_sync_mappings();
4229
4230 mutex_lock(&sessions_mutex);
4231 list_add_tail(&transport->node, &lttng_counter_transport_list);
4232 mutex_unlock(&sessions_mutex);
4233 }
4234 EXPORT_SYMBOL_GPL(lttng_counter_transport_register);
4235
4236 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
4237 {
4238 mutex_lock(&sessions_mutex);
4239 list_del(&transport->node);
4240 mutex_unlock(&sessions_mutex);
4241 }
4242 EXPORT_SYMBOL_GPL(lttng_counter_transport_unregister);
4243
4244 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
4245
4246 enum cpuhp_state lttng_hp_prepare;
4247 enum cpuhp_state lttng_hp_online;
4248
4249 static int lttng_hotplug_prepare(unsigned int cpu, struct hlist_node *node)
4250 {
4251 struct lttng_cpuhp_node *lttng_node;
4252
4253 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4254 switch (lttng_node->component) {
4255 case LTTNG_RING_BUFFER_FRONTEND:
4256 return 0;
4257 case LTTNG_RING_BUFFER_BACKEND:
4258 return lttng_cpuhp_rb_backend_prepare(cpu, lttng_node);
4259 case LTTNG_RING_BUFFER_ITER:
4260 return 0;
4261 case LTTNG_CONTEXT_PERF_COUNTERS:
4262 return 0;
4263 default:
4264 return -EINVAL;
4265 }
4266 }
4267
4268 static int lttng_hotplug_dead(unsigned int cpu, struct hlist_node *node)
4269 {
4270 struct lttng_cpuhp_node *lttng_node;
4271
4272 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4273 switch (lttng_node->component) {
4274 case LTTNG_RING_BUFFER_FRONTEND:
4275 return lttng_cpuhp_rb_frontend_dead(cpu, lttng_node);
4276 case LTTNG_RING_BUFFER_BACKEND:
4277 return 0;
4278 case LTTNG_RING_BUFFER_ITER:
4279 return 0;
4280 case LTTNG_CONTEXT_PERF_COUNTERS:
4281 return lttng_cpuhp_perf_counter_dead(cpu, lttng_node);
4282 default:
4283 return -EINVAL;
4284 }
4285 }
4286
4287 static int lttng_hotplug_online(unsigned int cpu, struct hlist_node *node)
4288 {
4289 struct lttng_cpuhp_node *lttng_node;
4290
4291 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4292 switch (lttng_node->component) {
4293 case LTTNG_RING_BUFFER_FRONTEND:
4294 return lttng_cpuhp_rb_frontend_online(cpu, lttng_node);
4295 case LTTNG_RING_BUFFER_BACKEND:
4296 return 0;
4297 case LTTNG_RING_BUFFER_ITER:
4298 return lttng_cpuhp_rb_iter_online(cpu, lttng_node);
4299 case LTTNG_CONTEXT_PERF_COUNTERS:
4300 return lttng_cpuhp_perf_counter_online(cpu, lttng_node);
4301 default:
4302 return -EINVAL;
4303 }
4304 }
4305
4306 static int lttng_hotplug_offline(unsigned int cpu, struct hlist_node *node)
4307 {
4308 struct lttng_cpuhp_node *lttng_node;
4309
4310 lttng_node = container_of(node, struct lttng_cpuhp_node, node);
4311 switch (lttng_node->component) {
4312 case LTTNG_RING_BUFFER_FRONTEND:
4313 return lttng_cpuhp_rb_frontend_offline(cpu, lttng_node);
4314 case LTTNG_RING_BUFFER_BACKEND:
4315 return 0;
4316 case LTTNG_RING_BUFFER_ITER:
4317 return 0;
4318 case LTTNG_CONTEXT_PERF_COUNTERS:
4319 return 0;
4320 default:
4321 return -EINVAL;
4322 }
4323 }
4324
4325 static int __init lttng_init_cpu_hotplug(void)
4326 {
4327 int ret;
4328
4329 ret = cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN, "lttng:prepare",
4330 lttng_hotplug_prepare,
4331 lttng_hotplug_dead);
4332 if (ret < 0) {
4333 return ret;
4334 }
4335 lttng_hp_prepare = ret;
4336 lttng_rb_set_hp_prepare(ret);
4337
4338 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "lttng:online",
4339 lttng_hotplug_online,
4340 lttng_hotplug_offline);
4341 if (ret < 0) {
4342 cpuhp_remove_multi_state(lttng_hp_prepare);
4343 lttng_hp_prepare = 0;
4344 return ret;
4345 }
4346 lttng_hp_online = ret;
4347 lttng_rb_set_hp_online(ret);
4348
4349 return 0;
4350 }
4351
4352 static void __exit lttng_exit_cpu_hotplug(void)
4353 {
4354 lttng_rb_set_hp_online(0);
4355 cpuhp_remove_multi_state(lttng_hp_online);
4356 lttng_rb_set_hp_prepare(0);
4357 cpuhp_remove_multi_state(lttng_hp_prepare);
4358 }
4359
4360 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4361 static int lttng_init_cpu_hotplug(void)
4362 {
4363 return 0;
4364 }
4365 static void lttng_exit_cpu_hotplug(void)
4366 {
4367 }
4368 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
4369
4370 static int __init lttng_events_init(void)
4371 {
4372 int ret;
4373
4374 ret = wrapper_lttng_fixup_sig(THIS_MODULE);
4375 if (ret)
4376 return ret;
4377 ret = wrapper_get_pfnblock_flags_mask_init();
4378 if (ret)
4379 return ret;
4380 ret = wrapper_get_pageblock_flags_mask_init();
4381 if (ret)
4382 return ret;
4383 ret = lttng_probes_init();
4384 if (ret)
4385 return ret;
4386 ret = lttng_context_init();
4387 if (ret)
4388 return ret;
4389 ret = lttng_tracepoint_init();
4390 if (ret)
4391 goto error_tp;
4392 event_recorder_cache = KMEM_CACHE(lttng_kernel_event_recorder, 0);
4393 if (!event_recorder_cache) {
4394 ret = -ENOMEM;
4395 goto error_kmem_event_recorder;
4396 }
4397 event_recorder_private_cache = KMEM_CACHE(lttng_kernel_event_recorder_private, 0);
4398 if (!event_recorder_private_cache) {
4399 ret = -ENOMEM;
4400 goto error_kmem_event_recorder_private;
4401 }
4402 event_notifier_cache = KMEM_CACHE(lttng_kernel_event_notifier, 0);
4403 if (!event_notifier_cache) {
4404 ret = -ENOMEM;
4405 goto error_kmem_event_notifier;
4406 }
4407 event_notifier_private_cache = KMEM_CACHE(lttng_kernel_event_notifier_private, 0);
4408 if (!event_notifier_private_cache) {
4409 ret = -ENOMEM;
4410 goto error_kmem_event_notifier_private;
4411 }
4412 ret = lttng_abi_init();
4413 if (ret)
4414 goto error_abi;
4415 ret = lttng_logger_init();
4416 if (ret)
4417 goto error_logger;
4418 ret = lttng_init_cpu_hotplug();
4419 if (ret)
4420 goto error_hotplug;
4421 printk(KERN_NOTICE "LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
4422 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4423 __stringify(LTTNG_MODULES_MINOR_VERSION),
4424 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4425 LTTNG_MODULES_EXTRAVERSION,
4426 LTTNG_VERSION_NAME,
4427 #ifdef LTTNG_EXTRA_VERSION_GIT
4428 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4429 #else
4430 "",
4431 #endif
4432 #ifdef LTTNG_EXTRA_VERSION_NAME
4433 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4434 #else
4435 "");
4436 #endif
4437 #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
4438 printk(KERN_NOTICE "LTTng: Experimental bitwise enum enabled.\n");
4439 #endif /* CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM */
4440 return 0;
4441
4442 error_hotplug:
4443 lttng_logger_exit();
4444 error_logger:
4445 lttng_abi_exit();
4446 error_abi:
4447 kmem_cache_destroy(event_notifier_private_cache);
4448 error_kmem_event_notifier_private:
4449 kmem_cache_destroy(event_notifier_cache);
4450 error_kmem_event_notifier:
4451 kmem_cache_destroy(event_recorder_private_cache);
4452 error_kmem_event_recorder_private:
4453 kmem_cache_destroy(event_recorder_cache);
4454 error_kmem_event_recorder:
4455 lttng_tracepoint_exit();
4456 error_tp:
4457 lttng_context_exit();
4458 printk(KERN_NOTICE "LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
4459 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4460 __stringify(LTTNG_MODULES_MINOR_VERSION),
4461 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4462 LTTNG_MODULES_EXTRAVERSION,
4463 LTTNG_VERSION_NAME,
4464 #ifdef LTTNG_EXTRA_VERSION_GIT
4465 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4466 #else
4467 "",
4468 #endif
4469 #ifdef LTTNG_EXTRA_VERSION_NAME
4470 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4471 #else
4472 "");
4473 #endif
4474 return ret;
4475 }
4476
4477 module_init(lttng_events_init);
4478
4479 static void __exit lttng_events_exit(void)
4480 {
4481 struct lttng_kernel_session_private *session_priv, *tmpsession_priv;
4482
4483 lttng_exit_cpu_hotplug();
4484 lttng_logger_exit();
4485 lttng_abi_exit();
4486 list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, list)
4487 lttng_session_destroy(session_priv->pub);
4488 kmem_cache_destroy(event_recorder_cache);
4489 kmem_cache_destroy(event_recorder_private_cache);
4490 kmem_cache_destroy(event_notifier_cache);
4491 kmem_cache_destroy(event_notifier_private_cache);
4492 lttng_tracepoint_exit();
4493 lttng_context_exit();
4494 printk(KERN_NOTICE "LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
4495 __stringify(LTTNG_MODULES_MAJOR_VERSION),
4496 __stringify(LTTNG_MODULES_MINOR_VERSION),
4497 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION),
4498 LTTNG_MODULES_EXTRAVERSION,
4499 LTTNG_VERSION_NAME,
4500 #ifdef LTTNG_EXTRA_VERSION_GIT
4501 LTTNG_EXTRA_VERSION_GIT[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT,
4502 #else
4503 "",
4504 #endif
4505 #ifdef LTTNG_EXTRA_VERSION_NAME
4506 LTTNG_EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME);
4507 #else
4508 "");
4509 #endif
4510 }
4511
4512 module_exit(lttng_events_exit);
4513
4514 #include <generated/patches.h>
4515 #ifdef LTTNG_EXTRA_VERSION_GIT
4516 MODULE_INFO(extra_version_git, LTTNG_EXTRA_VERSION_GIT);
4517 #endif
4518 #ifdef LTTNG_EXTRA_VERSION_NAME
4519 MODULE_INFO(extra_version_name, LTTNG_EXTRA_VERSION_NAME);
4520 #endif
4521 MODULE_LICENSE("GPL and additional rights");
4522 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
4523 MODULE_DESCRIPTION("LTTng tracer");
4524 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
4525 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
4526 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
4527 LTTNG_MODULES_EXTRAVERSION);
LTTng 2.0/0.x modules
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