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