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