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