1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
5 * Holds LTTng per-session event registry.
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
11 * This page_alloc.h wrapper needs to be included before gfpflags.h because it
12 * overrides a function with a define.
14 #include "wrapper/page_alloc.h"
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>
31 #include <wrapper/uuid.h>
32 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
33 #include <wrapper/random.h>
34 #include <wrapper/tracepoint.h>
35 #include <wrapper/list.h>
36 #include <wrapper/types.h>
37 #include <lttng/kernel-version.h>
38 #include <lttng/events.h>
39 #include <lttng/tracer.h>
40 #include <lttng/abi-old.h>
41 #include <lttng/endian.h>
42 #include <lttng/string-utils.h>
43 #include <lttng/utils.h>
44 #include <ringbuffer/backend.h>
45 #include <ringbuffer/frontend.h>
46 #include <wrapper/time.h>
48 #define METADATA_CACHE_DEFAULT_SIZE 4096
50 static LIST_HEAD(sessions
);
51 static LIST_HEAD(lttng_transport_list
);
53 * Protect the sessions and metadata caches.
55 static DEFINE_MUTEX(sessions_mutex
);
56 static struct kmem_cache
*event_cache
;
58 static void lttng_session_lazy_sync_event_enablers(struct lttng_session
*session
);
59 static void lttng_session_sync_event_enablers(struct lttng_session
*session
);
60 static void lttng_event_enabler_destroy(struct lttng_event_enabler
*event_enabler
);
62 static void _lttng_event_destroy(struct lttng_event
*event
);
63 static void _lttng_channel_destroy(struct lttng_channel
*chan
);
64 static int _lttng_event_unregister(struct lttng_event
*event
);
66 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
67 struct lttng_channel
*chan
,
68 struct lttng_event
*event
);
70 int _lttng_session_metadata_statedump(struct lttng_session
*session
);
72 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
);
74 int _lttng_type_statedump(struct lttng_session
*session
,
75 const struct lttng_type
*type
,
78 int _lttng_field_statedump(struct lttng_session
*session
,
79 const struct lttng_event_field
*field
,
82 void synchronize_trace(void)
84 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,1,0))
90 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
91 #ifdef CONFIG_PREEMPT_RT_FULL
94 #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
95 #ifdef CONFIG_PREEMPT_RT
98 #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
101 void lttng_lock_sessions(void)
103 mutex_lock(&sessions_mutex
);
106 void lttng_unlock_sessions(void)
108 mutex_unlock(&sessions_mutex
);
112 * Called with sessions lock held.
114 int lttng_session_active(void)
116 struct lttng_session
*iter
;
118 list_for_each_entry(iter
, &sessions
, list
) {
125 struct lttng_session
*lttng_session_create(void)
127 struct lttng_session
*session
;
128 struct lttng_metadata_cache
*metadata_cache
;
131 mutex_lock(&sessions_mutex
);
132 session
= lttng_kvzalloc(sizeof(struct lttng_session
), GFP_KERNEL
);
135 INIT_LIST_HEAD(&session
->chan
);
136 INIT_LIST_HEAD(&session
->events
);
137 lttng_guid_gen(&session
->uuid
);
139 metadata_cache
= kzalloc(sizeof(struct lttng_metadata_cache
),
142 goto err_free_session
;
143 metadata_cache
->data
= vzalloc(METADATA_CACHE_DEFAULT_SIZE
);
144 if (!metadata_cache
->data
)
146 metadata_cache
->cache_alloc
= METADATA_CACHE_DEFAULT_SIZE
;
147 kref_init(&metadata_cache
->refcount
);
148 mutex_init(&metadata_cache
->lock
);
149 session
->metadata_cache
= metadata_cache
;
150 INIT_LIST_HEAD(&metadata_cache
->metadata_stream
);
151 memcpy(&metadata_cache
->uuid
, &session
->uuid
,
152 sizeof(metadata_cache
->uuid
));
153 INIT_LIST_HEAD(&session
->enablers_head
);
154 for (i
= 0; i
< LTTNG_EVENT_HT_SIZE
; i
++)
155 INIT_HLIST_HEAD(&session
->events_ht
.table
[i
]);
156 list_add(&session
->list
, &sessions
);
157 session
->pid_tracker
.session
= session
;
158 session
->pid_tracker
.tracker_type
= TRACKER_PID
;
159 session
->vpid_tracker
.session
= session
;
160 session
->vpid_tracker
.tracker_type
= TRACKER_VPID
;
161 session
->uid_tracker
.session
= session
;
162 session
->uid_tracker
.tracker_type
= TRACKER_UID
;
163 session
->vuid_tracker
.session
= session
;
164 session
->vuid_tracker
.tracker_type
= TRACKER_VUID
;
165 session
->gid_tracker
.session
= session
;
166 session
->gid_tracker
.tracker_type
= TRACKER_GID
;
167 session
->vgid_tracker
.session
= session
;
168 session
->vgid_tracker
.tracker_type
= TRACKER_VGID
;
169 mutex_unlock(&sessions_mutex
);
173 kfree(metadata_cache
);
175 lttng_kvfree(session
);
177 mutex_unlock(&sessions_mutex
);
181 void metadata_cache_destroy(struct kref
*kref
)
183 struct lttng_metadata_cache
*cache
=
184 container_of(kref
, struct lttng_metadata_cache
, refcount
);
189 void lttng_session_destroy(struct lttng_session
*session
)
191 struct lttng_channel
*chan
, *tmpchan
;
192 struct lttng_event
*event
, *tmpevent
;
193 struct lttng_metadata_stream
*metadata_stream
;
194 struct lttng_event_enabler
*event_enabler
, *tmp_event_enabler
;
197 mutex_lock(&sessions_mutex
);
198 WRITE_ONCE(session
->active
, 0);
199 list_for_each_entry(chan
, &session
->chan
, list
) {
200 ret
= lttng_syscalls_unregister(chan
);
203 list_for_each_entry(event
, &session
->events
, list
) {
204 ret
= _lttng_event_unregister(event
);
207 synchronize_trace(); /* Wait for in-flight events to complete */
208 list_for_each_entry(chan
, &session
->chan
, list
) {
209 ret
= lttng_syscalls_destroy(chan
);
212 list_for_each_entry_safe(event_enabler
, tmp_event_enabler
,
213 &session
->enablers_head
, node
)
214 lttng_event_enabler_destroy(event_enabler
);
215 list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
216 _lttng_event_destroy(event
);
217 list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
) {
218 BUG_ON(chan
->channel_type
== METADATA_CHANNEL
);
219 _lttng_channel_destroy(chan
);
221 mutex_lock(&session
->metadata_cache
->lock
);
222 list_for_each_entry(metadata_stream
, &session
->metadata_cache
->metadata_stream
, list
)
223 _lttng_metadata_channel_hangup(metadata_stream
);
224 mutex_unlock(&session
->metadata_cache
->lock
);
225 lttng_id_tracker_destroy(&session
->pid_tracker
, false);
226 lttng_id_tracker_destroy(&session
->vpid_tracker
, false);
227 lttng_id_tracker_destroy(&session
->uid_tracker
, false);
228 lttng_id_tracker_destroy(&session
->vuid_tracker
, false);
229 lttng_id_tracker_destroy(&session
->gid_tracker
, false);
230 lttng_id_tracker_destroy(&session
->vgid_tracker
, false);
231 kref_put(&session
->metadata_cache
->refcount
, metadata_cache_destroy
);
232 list_del(&session
->list
);
233 mutex_unlock(&sessions_mutex
);
234 lttng_kvfree(session
);
237 int lttng_session_statedump(struct lttng_session
*session
)
241 mutex_lock(&sessions_mutex
);
242 ret
= lttng_statedump_start(session
);
243 mutex_unlock(&sessions_mutex
);
247 int lttng_session_enable(struct lttng_session
*session
)
250 struct lttng_channel
*chan
;
252 mutex_lock(&sessions_mutex
);
253 if (session
->active
) {
258 /* Set transient enabler state to "enabled" */
261 /* We need to sync enablers with session before activation. */
262 lttng_session_sync_event_enablers(session
);
265 * Snapshot the number of events per channel to know the type of header
268 list_for_each_entry(chan
, &session
->chan
, list
) {
269 if (chan
->header_type
)
270 continue; /* don't change it if session stop/restart */
271 if (chan
->free_event_id
< 31)
272 chan
->header_type
= 1; /* compact */
274 chan
->header_type
= 2; /* large */
277 /* Clear each stream's quiescent state. */
278 list_for_each_entry(chan
, &session
->chan
, list
) {
279 if (chan
->channel_type
!= METADATA_CHANNEL
)
280 lib_ring_buffer_clear_quiescent_channel(chan
->chan
);
283 WRITE_ONCE(session
->active
, 1);
284 WRITE_ONCE(session
->been_active
, 1);
285 ret
= _lttng_session_metadata_statedump(session
);
287 WRITE_ONCE(session
->active
, 0);
290 ret
= lttng_statedump_start(session
);
292 WRITE_ONCE(session
->active
, 0);
294 mutex_unlock(&sessions_mutex
);
298 int lttng_session_disable(struct lttng_session
*session
)
301 struct lttng_channel
*chan
;
303 mutex_lock(&sessions_mutex
);
304 if (!session
->active
) {
308 WRITE_ONCE(session
->active
, 0);
310 /* Set transient enabler state to "disabled" */
312 lttng_session_sync_event_enablers(session
);
314 /* Set each stream's quiescent state. */
315 list_for_each_entry(chan
, &session
->chan
, list
) {
316 if (chan
->channel_type
!= METADATA_CHANNEL
)
317 lib_ring_buffer_set_quiescent_channel(chan
->chan
);
320 mutex_unlock(&sessions_mutex
);
324 int lttng_session_metadata_regenerate(struct lttng_session
*session
)
327 struct lttng_channel
*chan
;
328 struct lttng_event
*event
;
329 struct lttng_metadata_cache
*cache
= session
->metadata_cache
;
330 struct lttng_metadata_stream
*stream
;
332 mutex_lock(&sessions_mutex
);
333 if (!session
->active
) {
338 mutex_lock(&cache
->lock
);
339 memset(cache
->data
, 0, cache
->cache_alloc
);
340 cache
->metadata_written
= 0;
342 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
) {
343 stream
->metadata_out
= 0;
344 stream
->metadata_in
= 0;
346 mutex_unlock(&cache
->lock
);
348 session
->metadata_dumped
= 0;
349 list_for_each_entry(chan
, &session
->chan
, list
) {
350 chan
->metadata_dumped
= 0;
353 list_for_each_entry(event
, &session
->events
, list
) {
354 event
->metadata_dumped
= 0;
357 ret
= _lttng_session_metadata_statedump(session
);
360 mutex_unlock(&sessions_mutex
);
364 int lttng_channel_enable(struct lttng_channel
*channel
)
368 mutex_lock(&sessions_mutex
);
369 if (channel
->channel_type
== METADATA_CHANNEL
) {
373 if (channel
->enabled
) {
377 /* Set transient enabler state to "enabled" */
379 lttng_session_sync_event_enablers(channel
->session
);
380 /* Set atomically the state to "enabled" */
381 WRITE_ONCE(channel
->enabled
, 1);
383 mutex_unlock(&sessions_mutex
);
387 int lttng_channel_disable(struct lttng_channel
*channel
)
391 mutex_lock(&sessions_mutex
);
392 if (channel
->channel_type
== METADATA_CHANNEL
) {
396 if (!channel
->enabled
) {
400 /* Set atomically the state to "disabled" */
401 WRITE_ONCE(channel
->enabled
, 0);
402 /* Set transient enabler state to "enabled" */
404 lttng_session_sync_event_enablers(channel
->session
);
406 mutex_unlock(&sessions_mutex
);
410 int lttng_event_enable(struct lttng_event
*event
)
414 mutex_lock(&sessions_mutex
);
415 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
419 if (event
->enabled
) {
423 switch (event
->instrumentation
) {
424 case LTTNG_KERNEL_TRACEPOINT
:
425 case LTTNG_KERNEL_SYSCALL
:
428 case LTTNG_KERNEL_KPROBE
:
429 case LTTNG_KERNEL_UPROBE
:
430 case LTTNG_KERNEL_NOOP
:
431 WRITE_ONCE(event
->enabled
, 1);
433 case LTTNG_KERNEL_KRETPROBE
:
434 ret
= lttng_kretprobes_event_enable_state(event
, 1);
436 case LTTNG_KERNEL_FUNCTION
: /* Fall-through. */
442 mutex_unlock(&sessions_mutex
);
446 int lttng_event_disable(struct lttng_event
*event
)
450 mutex_lock(&sessions_mutex
);
451 if (event
->chan
->channel_type
== METADATA_CHANNEL
) {
455 if (!event
->enabled
) {
459 switch (event
->instrumentation
) {
460 case LTTNG_KERNEL_TRACEPOINT
:
461 case LTTNG_KERNEL_SYSCALL
:
464 case LTTNG_KERNEL_KPROBE
:
465 case LTTNG_KERNEL_UPROBE
:
466 case LTTNG_KERNEL_NOOP
:
467 WRITE_ONCE(event
->enabled
, 0);
469 case LTTNG_KERNEL_KRETPROBE
:
470 ret
= lttng_kretprobes_event_enable_state(event
, 0);
472 case LTTNG_KERNEL_FUNCTION
: /* Fall-through. */
478 mutex_unlock(&sessions_mutex
);
482 static struct lttng_transport
*lttng_transport_find(const char *name
)
484 struct lttng_transport
*transport
;
486 list_for_each_entry(transport
, <tng_transport_list
, node
) {
487 if (!strcmp(transport
->name
, name
))
493 struct lttng_channel
*lttng_channel_create(struct lttng_session
*session
,
494 const char *transport_name
,
496 size_t subbuf_size
, size_t num_subbuf
,
497 unsigned int switch_timer_interval
,
498 unsigned int read_timer_interval
,
499 enum channel_type channel_type
)
501 struct lttng_channel
*chan
;
502 struct lttng_transport
*transport
= NULL
;
504 mutex_lock(&sessions_mutex
);
505 if (session
->been_active
&& channel_type
!= METADATA_CHANNEL
)
506 goto active
; /* Refuse to add channel to active session */
507 transport
= lttng_transport_find(transport_name
);
509 printk(KERN_WARNING
"LTTng: transport %s not found\n",
513 if (!try_module_get(transport
->owner
)) {
514 printk(KERN_WARNING
"LTTng: Can't lock transport module.\n");
517 chan
= kzalloc(sizeof(struct lttng_channel
), GFP_KERNEL
);
520 chan
->session
= session
;
521 chan
->id
= session
->free_chan_id
++;
522 chan
->ops
= &transport
->ops
;
524 * Note: the channel creation op already writes into the packet
525 * headers. Therefore the "chan" information used as input
526 * should be already accessible.
528 chan
->chan
= transport
->ops
.channel_create(transport_name
,
529 chan
, buf_addr
, subbuf_size
, num_subbuf
,
530 switch_timer_interval
, read_timer_interval
);
535 chan
->transport
= transport
;
536 chan
->channel_type
= channel_type
;
537 list_add(&chan
->list
, &session
->chan
);
538 mutex_unlock(&sessions_mutex
);
545 module_put(transport
->owner
);
548 mutex_unlock(&sessions_mutex
);
553 * Only used internally at session destruction for per-cpu channels, and
554 * when metadata channel is released.
555 * Needs to be called with sessions mutex held.
558 void _lttng_channel_destroy(struct lttng_channel
*chan
)
560 chan
->ops
->channel_destroy(chan
->chan
);
561 module_put(chan
->transport
->owner
);
562 list_del(&chan
->list
);
563 lttng_destroy_context(chan
->ctx
);
567 void lttng_metadata_channel_destroy(struct lttng_channel
*chan
)
569 BUG_ON(chan
->channel_type
!= METADATA_CHANNEL
);
571 /* Protect the metadata cache with the sessions_mutex. */
572 mutex_lock(&sessions_mutex
);
573 _lttng_channel_destroy(chan
);
574 mutex_unlock(&sessions_mutex
);
576 EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy
);
579 void _lttng_metadata_channel_hangup(struct lttng_metadata_stream
*stream
)
581 stream
->finalized
= 1;
582 wake_up_interruptible(&stream
->read_wait
);
586 * Supports event creation while tracing session is active.
587 * Needs to be called with sessions mutex held.
589 struct lttng_event
*_lttng_event_create(struct lttng_channel
*chan
,
590 struct lttng_kernel_event
*event_param
,
592 const struct lttng_event_desc
*event_desc
,
593 enum lttng_kernel_instrumentation itype
)
595 struct lttng_session
*session
= chan
->session
;
596 struct lttng_event
*event
;
597 const char *event_name
;
598 struct hlist_head
*head
;
601 if (chan
->free_event_id
== -1U) {
607 case LTTNG_KERNEL_TRACEPOINT
:
608 event_name
= event_desc
->name
;
610 case LTTNG_KERNEL_KPROBE
:
611 case LTTNG_KERNEL_UPROBE
:
612 case LTTNG_KERNEL_KRETPROBE
:
613 case LTTNG_KERNEL_NOOP
:
614 case LTTNG_KERNEL_SYSCALL
:
615 event_name
= event_param
->name
;
617 case LTTNG_KERNEL_FUNCTION
: /* Fall-through. */
624 head
= utils_borrow_hash_table_bucket(session
->events_ht
.table
,
625 LTTNG_EVENT_HT_SIZE
, event_name
);
626 lttng_hlist_for_each_entry(event
, head
, hlist
) {
627 WARN_ON_ONCE(!event
->desc
);
628 if (!strncmp(event
->desc
->name
, event_name
,
629 LTTNG_KERNEL_SYM_NAME_LEN
- 1)
630 && chan
== event
->chan
) {
636 event
= kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
642 event
->filter
= filter
;
643 event
->id
= chan
->free_event_id
++;
644 event
->instrumentation
= itype
;
645 event
->evtype
= LTTNG_TYPE_EVENT
;
646 INIT_LIST_HEAD(&event
->bytecode_runtime_head
);
647 INIT_LIST_HEAD(&event
->enablers_ref_head
);
650 case LTTNG_KERNEL_TRACEPOINT
:
651 /* Event will be enabled by enabler sync. */
653 event
->registered
= 0;
654 event
->desc
= lttng_event_get(event_name
);
659 /* Populate lttng_event structure before event registration. */
662 case LTTNG_KERNEL_KPROBE
:
664 * Needs to be explicitly enabled after creation, since
665 * we may want to apply filters.
668 event
->registered
= 1;
670 * Populate lttng_event structure before event
674 ret
= lttng_kprobes_register(event_name
,
675 event_param
->u
.kprobe
.symbol_name
,
676 event_param
->u
.kprobe
.offset
,
677 event_param
->u
.kprobe
.addr
,
683 ret
= try_module_get(event
->desc
->owner
);
686 case LTTNG_KERNEL_KRETPROBE
:
688 struct lttng_event
*event_return
;
690 /* kretprobe defines 2 events */
692 * Needs to be explicitly enabled after creation, since
693 * we may want to apply filters.
696 event
->registered
= 1;
698 kmem_cache_zalloc(event_cache
, GFP_KERNEL
);
703 event_return
->chan
= chan
;
704 event_return
->filter
= filter
;
705 event_return
->id
= chan
->free_event_id
++;
706 event_return
->enabled
= 0;
707 event_return
->registered
= 1;
708 event_return
->instrumentation
= itype
;
710 * Populate lttng_event structure before kretprobe registration.
713 ret
= lttng_kretprobes_register(event_name
,
714 event_param
->u
.kretprobe
.symbol_name
,
715 event_param
->u
.kretprobe
.offset
,
716 event_param
->u
.kretprobe
.addr
,
717 event
, event_return
);
719 kmem_cache_free(event_cache
, event_return
);
723 /* Take 2 refs on the module: one per event. */
724 ret
= try_module_get(event
->desc
->owner
);
726 ret
= try_module_get(event
->desc
->owner
);
728 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
,
730 WARN_ON_ONCE(ret
> 0);
732 kmem_cache_free(event_cache
, event_return
);
733 module_put(event
->desc
->owner
);
734 module_put(event
->desc
->owner
);
735 goto statedump_error
;
737 list_add(&event_return
->list
, &chan
->session
->events
);
740 case LTTNG_KERNEL_NOOP
:
741 case LTTNG_KERNEL_SYSCALL
:
743 * Needs to be explicitly enabled after creation, since
744 * we may want to apply filters.
747 event
->registered
= 0;
748 event
->desc
= event_desc
;
749 switch (event_param
->u
.syscall
.entryexit
) {
750 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT
:
753 case LTTNG_KERNEL_SYSCALL_ENTRY
:
754 event
->u
.syscall
.entryexit
= LTTNG_SYSCALL_ENTRY
;
756 case LTTNG_KERNEL_SYSCALL_EXIT
:
757 event
->u
.syscall
.entryexit
= LTTNG_SYSCALL_EXIT
;
760 switch (event_param
->u
.syscall
.abi
) {
761 case LTTNG_KERNEL_SYSCALL_ABI_ALL
:
764 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE
:
765 event
->u
.syscall
.abi
= LTTNG_SYSCALL_ABI_NATIVE
;
767 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT
:
768 event
->u
.syscall
.abi
= LTTNG_SYSCALL_ABI_COMPAT
;
776 case LTTNG_KERNEL_UPROBE
:
778 * Needs to be explicitly enabled after creation, since
779 * we may want to apply filters.
782 event
->registered
= 1;
785 * Populate lttng_event structure before event
790 ret
= lttng_uprobes_register(event_param
->name
,
791 event_param
->u
.uprobe
.fd
,
795 ret
= try_module_get(event
->desc
->owner
);
798 case LTTNG_KERNEL_FUNCTION
: /* Fall-through */
804 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
805 WARN_ON_ONCE(ret
> 0);
807 goto statedump_error
;
809 hlist_add_head(&event
->hlist
, head
);
810 list_add(&event
->list
, &chan
->session
->events
);
814 /* If a statedump error occurs, events will not be readable. */
816 kmem_cache_free(event_cache
, event
);
824 struct lttng_event
*lttng_event_create(struct lttng_channel
*chan
,
825 struct lttng_kernel_event
*event_param
,
827 const struct lttng_event_desc
*event_desc
,
828 enum lttng_kernel_instrumentation itype
)
830 struct lttng_event
*event
;
832 mutex_lock(&sessions_mutex
);
833 event
= _lttng_event_create(chan
, event_param
, filter
, event_desc
,
835 mutex_unlock(&sessions_mutex
);
839 /* Only used for tracepoints for now. */
841 void register_event(struct lttng_event
*event
)
843 const struct lttng_event_desc
*desc
;
846 if (event
->registered
)
850 switch (event
->instrumentation
) {
851 case LTTNG_KERNEL_TRACEPOINT
:
852 ret
= lttng_wrapper_tracepoint_probe_register(desc
->kname
,
853 desc
->probe_callback
,
856 case LTTNG_KERNEL_SYSCALL
:
857 ret
= lttng_syscall_filter_enable(event
->chan
, event
);
859 case LTTNG_KERNEL_KPROBE
:
860 case LTTNG_KERNEL_UPROBE
:
861 case LTTNG_KERNEL_KRETPROBE
:
862 case LTTNG_KERNEL_NOOP
:
865 case LTTNG_KERNEL_FUNCTION
: /* Fall-through */
870 event
->registered
= 1;
874 * Only used internally at session destruction.
876 int _lttng_event_unregister(struct lttng_event
*event
)
878 const struct lttng_event_desc
*desc
;
881 if (!event
->registered
)
885 switch (event
->instrumentation
) {
886 case LTTNG_KERNEL_TRACEPOINT
:
887 ret
= lttng_wrapper_tracepoint_probe_unregister(event
->desc
->kname
,
888 event
->desc
->probe_callback
,
891 case LTTNG_KERNEL_KPROBE
:
892 lttng_kprobes_unregister(event
);
895 case LTTNG_KERNEL_KRETPROBE
:
896 lttng_kretprobes_unregister(event
);
899 case LTTNG_KERNEL_SYSCALL
:
900 ret
= lttng_syscall_filter_disable(event
->chan
, event
);
902 case LTTNG_KERNEL_NOOP
:
905 case LTTNG_KERNEL_UPROBE
:
906 lttng_uprobes_unregister(event
);
909 case LTTNG_KERNEL_FUNCTION
: /* Fall-through */
914 event
->registered
= 0;
919 * Only used internally at session destruction.
922 void _lttng_event_destroy(struct lttng_event
*event
)
924 switch (event
->instrumentation
) {
925 case LTTNG_KERNEL_TRACEPOINT
:
926 lttng_event_put(event
->desc
);
928 case LTTNG_KERNEL_KPROBE
:
929 module_put(event
->desc
->owner
);
930 lttng_kprobes_destroy_private(event
);
932 case LTTNG_KERNEL_KRETPROBE
:
933 module_put(event
->desc
->owner
);
934 lttng_kretprobes_destroy_private(event
);
936 case LTTNG_KERNEL_NOOP
:
937 case LTTNG_KERNEL_SYSCALL
:
939 case LTTNG_KERNEL_UPROBE
:
940 module_put(event
->desc
->owner
);
941 lttng_uprobes_destroy_private(event
);
943 case LTTNG_KERNEL_FUNCTION
: /* Fall-through */
947 list_del(&event
->list
);
948 lttng_destroy_context(event
->ctx
);
949 kmem_cache_free(event_cache
, event
);
952 struct lttng_id_tracker
*get_tracker(struct lttng_session
*session
,
953 enum tracker_type tracker_type
)
955 switch (tracker_type
) {
957 return &session
->pid_tracker
;
959 return &session
->vpid_tracker
;
961 return &session
->uid_tracker
;
963 return &session
->vuid_tracker
;
965 return &session
->gid_tracker
;
967 return &session
->vgid_tracker
;
974 int lttng_session_track_id(struct lttng_session
*session
,
975 enum tracker_type tracker_type
, int id
)
977 struct lttng_id_tracker
*tracker
;
980 tracker
= get_tracker(session
, tracker_type
);
985 mutex_lock(&sessions_mutex
);
987 /* track all ids: destroy tracker. */
988 lttng_id_tracker_destroy(tracker
, true);
991 ret
= lttng_id_tracker_add(tracker
, id
);
993 mutex_unlock(&sessions_mutex
);
997 int lttng_session_untrack_id(struct lttng_session
*session
,
998 enum tracker_type tracker_type
, int id
)
1000 struct lttng_id_tracker
*tracker
;
1003 tracker
= get_tracker(session
, tracker_type
);
1008 mutex_lock(&sessions_mutex
);
1010 /* untrack all ids: replace by empty tracker. */
1011 ret
= lttng_id_tracker_empty_set(tracker
);
1013 ret
= lttng_id_tracker_del(tracker
, id
);
1015 mutex_unlock(&sessions_mutex
);
1020 void *id_list_start(struct seq_file
*m
, loff_t
*pos
)
1022 struct lttng_id_tracker
*id_tracker
= m
->private;
1023 struct lttng_id_tracker_rcu
*id_tracker_p
= id_tracker
->p
;
1024 struct lttng_id_hash_node
*e
;
1027 mutex_lock(&sessions_mutex
);
1029 for (i
= 0; i
< LTTNG_ID_TABLE_SIZE
; i
++) {
1030 struct hlist_head
*head
= &id_tracker_p
->id_hash
[i
];
1032 lttng_hlist_for_each_entry(e
, head
, hlist
) {
1038 /* ID tracker disabled. */
1039 if (iter
>= *pos
&& iter
== 0) {
1040 return id_tracker_p
; /* empty tracker */
1048 /* Called with sessions_mutex held. */
1050 void *id_list_next(struct seq_file
*m
, void *p
, loff_t
*ppos
)
1052 struct lttng_id_tracker
*id_tracker
= m
->private;
1053 struct lttng_id_tracker_rcu
*id_tracker_p
= id_tracker
->p
;
1054 struct lttng_id_hash_node
*e
;
1059 for (i
= 0; i
< LTTNG_ID_TABLE_SIZE
; i
++) {
1060 struct hlist_head
*head
= &id_tracker_p
->id_hash
[i
];
1062 lttng_hlist_for_each_entry(e
, head
, hlist
) {
1063 if (iter
++ >= *ppos
)
1068 /* ID tracker disabled. */
1069 if (iter
>= *ppos
&& iter
== 0)
1070 return p
; /* empty tracker */
1079 void id_list_stop(struct seq_file
*m
, void *p
)
1081 mutex_unlock(&sessions_mutex
);
1085 int id_list_show(struct seq_file
*m
, void *p
)
1087 struct lttng_id_tracker
*id_tracker
= m
->private;
1088 struct lttng_id_tracker_rcu
*id_tracker_p
= id_tracker
->p
;
1091 if (p
== id_tracker_p
) {
1092 /* Tracker disabled. */
1095 const struct lttng_id_hash_node
*e
= p
;
1097 id
= lttng_id_tracker_get_node_id(e
);
1099 switch (id_tracker
->tracker_type
) {
1101 seq_printf(m
, "process { pid = %d; };\n", id
);
1104 seq_printf(m
, "process { vpid = %d; };\n", id
);
1107 seq_printf(m
, "user { uid = %d; };\n", id
);
1110 seq_printf(m
, "user { vuid = %d; };\n", id
);
1113 seq_printf(m
, "group { gid = %d; };\n", id
);
1116 seq_printf(m
, "group { vgid = %d; };\n", id
);
1119 seq_printf(m
, "UNKNOWN { field = %d };\n", id
);
1125 const struct seq_operations lttng_tracker_ids_list_seq_ops
= {
1126 .start
= id_list_start
,
1127 .next
= id_list_next
,
1128 .stop
= id_list_stop
,
1129 .show
= id_list_show
,
1133 int lttng_tracker_ids_list_open(struct inode
*inode
, struct file
*file
)
1135 return seq_open(file
, <tng_tracker_ids_list_seq_ops
);
1139 int lttng_tracker_ids_list_release(struct inode
*inode
, struct file
*file
)
1141 struct seq_file
*m
= file
->private_data
;
1142 struct lttng_id_tracker
*id_tracker
= m
->private;
1145 WARN_ON_ONCE(!id_tracker
);
1146 ret
= seq_release(inode
, file
);
1148 fput(id_tracker
->session
->file
);
1152 const struct file_operations lttng_tracker_ids_list_fops
= {
1153 .owner
= THIS_MODULE
,
1154 .open
= lttng_tracker_ids_list_open
,
1156 .llseek
= seq_lseek
,
1157 .release
= lttng_tracker_ids_list_release
,
1160 int lttng_session_list_tracker_ids(struct lttng_session
*session
,
1161 enum tracker_type tracker_type
)
1163 struct file
*tracker_ids_list_file
;
1167 file_fd
= lttng_get_unused_fd();
1173 tracker_ids_list_file
= anon_inode_getfile("[lttng_tracker_ids_list]",
1174 <tng_tracker_ids_list_fops
,
1176 if (IS_ERR(tracker_ids_list_file
)) {
1177 ret
= PTR_ERR(tracker_ids_list_file
);
1180 if (!atomic_long_add_unless(&session
->file
->f_count
, 1, LONG_MAX
)) {
1182 goto refcount_error
;
1184 ret
= lttng_tracker_ids_list_fops
.open(NULL
, tracker_ids_list_file
);
1187 m
= tracker_ids_list_file
->private_data
;
1189 m
->private = get_tracker(session
, tracker_type
);
1190 BUG_ON(!m
->private);
1191 fd_install(file_fd
, tracker_ids_list_file
);
1196 atomic_long_dec(&session
->file
->f_count
);
1198 fput(tracker_ids_list_file
);
1200 put_unused_fd(file_fd
);
1206 * Enabler management.
1209 int lttng_match_enabler_star_glob(const char *desc_name
,
1210 const char *pattern
)
1212 if (!strutils_star_glob_match(pattern
, LTTNG_SIZE_MAX
,
1213 desc_name
, LTTNG_SIZE_MAX
))
1219 int lttng_match_enabler_name(const char *desc_name
,
1222 if (strcmp(desc_name
, name
))
1228 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
1229 struct lttng_enabler
*enabler
)
1231 const char *desc_name
, *enabler_name
;
1232 bool compat
= false, entry
= false;
1234 enabler_name
= enabler
->event_param
.name
;
1235 switch (enabler
->event_param
.instrumentation
) {
1236 case LTTNG_KERNEL_TRACEPOINT
:
1237 desc_name
= desc
->name
;
1238 switch (enabler
->format_type
) {
1239 case LTTNG_ENABLER_FORMAT_STAR_GLOB
:
1240 return lttng_match_enabler_star_glob(desc_name
, enabler_name
);
1241 case LTTNG_ENABLER_FORMAT_NAME
:
1242 return lttng_match_enabler_name(desc_name
, enabler_name
);
1247 case LTTNG_KERNEL_SYSCALL
:
1248 desc_name
= desc
->name
;
1249 if (!strncmp(desc_name
, "compat_", strlen("compat_"))) {
1250 desc_name
+= strlen("compat_");
1253 if (!strncmp(desc_name
, "syscall_exit_",
1254 strlen("syscall_exit_"))) {
1255 desc_name
+= strlen("syscall_exit_");
1256 } else if (!strncmp(desc_name
, "syscall_entry_",
1257 strlen("syscall_entry_"))) {
1258 desc_name
+= strlen("syscall_entry_");
1264 switch (enabler
->event_param
.u
.syscall
.entryexit
) {
1265 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT
:
1267 case LTTNG_KERNEL_SYSCALL_ENTRY
:
1271 case LTTNG_KERNEL_SYSCALL_EXIT
:
1278 switch (enabler
->event_param
.u
.syscall
.abi
) {
1279 case LTTNG_KERNEL_SYSCALL_ABI_ALL
:
1281 case LTTNG_KERNEL_SYSCALL_ABI_NATIVE
:
1285 case LTTNG_KERNEL_SYSCALL_ABI_COMPAT
:
1292 switch (enabler
->event_param
.u
.syscall
.match
) {
1293 case LTTNG_SYSCALL_MATCH_NAME
:
1294 switch (enabler
->format_type
) {
1295 case LTTNG_ENABLER_FORMAT_STAR_GLOB
:
1296 return lttng_match_enabler_star_glob(desc_name
, enabler_name
);
1297 case LTTNG_ENABLER_FORMAT_NAME
:
1298 return lttng_match_enabler_name(desc_name
, enabler_name
);
1303 case LTTNG_SYSCALL_MATCH_NR
:
1304 return -EINVAL
; /* Not implemented. */
1316 int lttng_event_enabler_match_event(struct lttng_event_enabler
*event_enabler
,
1317 struct lttng_event
*event
)
1319 struct lttng_enabler
*base_enabler
= lttng_event_enabler_as_enabler(
1322 if (base_enabler
->event_param
.instrumentation
!= event
->instrumentation
)
1324 if (lttng_desc_match_enabler(event
->desc
, base_enabler
)
1325 && event
->chan
== event_enabler
->chan
)
1332 struct lttng_enabler_ref
*lttng_enabler_ref(
1333 struct list_head
*enablers_ref_list
,
1334 struct lttng_enabler
*enabler
)
1336 struct lttng_enabler_ref
*enabler_ref
;
1338 list_for_each_entry(enabler_ref
, enablers_ref_list
, node
) {
1339 if (enabler_ref
->ref
== enabler
)
1346 void lttng_create_tracepoint_event_if_missing(struct lttng_event_enabler
*event_enabler
)
1348 struct lttng_session
*session
= event_enabler
->chan
->session
;
1349 struct lttng_probe_desc
*probe_desc
;
1350 const struct lttng_event_desc
*desc
;
1352 struct list_head
*probe_list
;
1354 probe_list
= lttng_get_probe_list_head();
1356 * For each probe event, if we find that a probe event matches
1357 * our enabler, create an associated lttng_event if not
1360 list_for_each_entry(probe_desc
, probe_list
, head
) {
1361 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
1363 struct hlist_head
*head
;
1364 struct lttng_event
*event
;
1366 desc
= probe_desc
->event_desc
[i
];
1367 if (!lttng_desc_match_enabler(desc
,
1368 lttng_event_enabler_as_enabler(event_enabler
)))
1372 * Check if already created.
1374 head
= utils_borrow_hash_table_bucket(
1375 session
->events_ht
.table
, LTTNG_EVENT_HT_SIZE
,
1377 lttng_hlist_for_each_entry(event
, head
, hlist
) {
1378 if (event
->desc
== desc
1379 && event
->chan
== event_enabler
->chan
)
1386 * We need to create an event for this
1389 event
= _lttng_event_create(event_enabler
->chan
,
1391 LTTNG_KERNEL_TRACEPOINT
);
1393 printk(KERN_INFO
"LTTng: Unable to create event %s\n",
1394 probe_desc
->event_desc
[i
]->name
);
1401 void lttng_create_syscall_event_if_missing(struct lttng_event_enabler
*event_enabler
)
1405 ret
= lttng_syscalls_register(event_enabler
->chan
, NULL
);
1410 * Create struct lttng_event if it is missing and present in the list of
1411 * tracepoint probes.
1412 * Should be called with sessions mutex held.
1415 void lttng_create_event_if_missing(struct lttng_event_enabler
*event_enabler
)
1417 switch (event_enabler
->base
.event_param
.instrumentation
) {
1418 case LTTNG_KERNEL_TRACEPOINT
:
1419 lttng_create_tracepoint_event_if_missing(event_enabler
);
1421 case LTTNG_KERNEL_SYSCALL
:
1422 lttng_create_syscall_event_if_missing(event_enabler
);
1431 * Create events associated with an event_enabler (if not already present),
1432 * and add backward reference from the event to the enabler.
1433 * Should be called with sessions mutex held.
1436 int lttng_event_enabler_ref_events(struct lttng_event_enabler
*event_enabler
)
1438 struct lttng_channel
*chan
= event_enabler
->chan
;
1439 struct lttng_session
*session
= event_enabler
->chan
->session
;
1440 struct lttng_enabler
*base_enabler
= lttng_event_enabler_as_enabler(event_enabler
);
1441 struct lttng_event
*event
;
1443 if (base_enabler
->event_param
.instrumentation
== LTTNG_KERNEL_SYSCALL
&&
1444 base_enabler
->event_param
.u
.syscall
.entryexit
== LTTNG_KERNEL_SYSCALL_ENTRYEXIT
&&
1445 base_enabler
->event_param
.u
.syscall
.abi
== LTTNG_KERNEL_SYSCALL_ABI_ALL
&&
1446 base_enabler
->event_param
.u
.syscall
.match
== LTTNG_SYSCALL_MATCH_NAME
&&
1447 !strcmp(base_enabler
->event_param
.name
, "*")) {
1448 if (base_enabler
->enabled
)
1449 WRITE_ONCE(chan
->syscall_all
, 1);
1451 WRITE_ONCE(chan
->syscall_all
, 0);
1454 /* First ensure that probe events are created for this enabler. */
1455 lttng_create_event_if_missing(event_enabler
);
1457 /* For each event matching event_enabler in session event list. */
1458 list_for_each_entry(event
, &session
->events
, list
) {
1459 struct lttng_enabler_ref
*enabler_ref
;
1461 if (!lttng_event_enabler_match_event(event_enabler
, event
))
1463 enabler_ref
= lttng_enabler_ref(&event
->enablers_ref_head
,
1464 lttng_event_enabler_as_enabler(event_enabler
));
1467 * If no backward ref, create it.
1468 * Add backward ref from event to event_enabler.
1470 enabler_ref
= kzalloc(sizeof(*enabler_ref
), GFP_KERNEL
);
1473 enabler_ref
->ref
= lttng_event_enabler_as_enabler(event_enabler
);
1474 list_add(&enabler_ref
->node
,
1475 &event
->enablers_ref_head
);
1479 * Link filter bytecodes if not linked yet.
1481 lttng_enabler_link_bytecode(event
->desc
,
1483 &event
->bytecode_runtime_head
,
1484 lttng_event_enabler_as_enabler(event_enabler
));
1486 /* TODO: merge event context. */
1492 * Called at module load: connect the probe on all enablers matching
1494 * Called with sessions lock held.
1496 int lttng_fix_pending_events(void)
1498 struct lttng_session
*session
;
1500 list_for_each_entry(session
, &sessions
, list
)
1501 lttng_session_lazy_sync_event_enablers(session
);
1505 struct lttng_event_enabler
*lttng_event_enabler_create(
1506 enum lttng_enabler_format_type format_type
,
1507 struct lttng_kernel_event
*event_param
,
1508 struct lttng_channel
*chan
)
1510 struct lttng_event_enabler
*event_enabler
;
1512 event_enabler
= kzalloc(sizeof(*event_enabler
), GFP_KERNEL
);
1515 event_enabler
->base
.format_type
= format_type
;
1516 INIT_LIST_HEAD(&event_enabler
->base
.filter_bytecode_head
);
1517 memcpy(&event_enabler
->base
.event_param
, event_param
,
1518 sizeof(event_enabler
->base
.event_param
));
1519 event_enabler
->chan
= chan
;
1521 event_enabler
->base
.enabled
= 0;
1522 event_enabler
->base
.evtype
= LTTNG_TYPE_ENABLER
;
1523 mutex_lock(&sessions_mutex
);
1524 list_add(&event_enabler
->node
, &event_enabler
->chan
->session
->enablers_head
);
1525 lttng_session_lazy_sync_event_enablers(event_enabler
->chan
->session
);
1526 mutex_unlock(&sessions_mutex
);
1527 return event_enabler
;
1530 int lttng_event_enabler_enable(struct lttng_event_enabler
*event_enabler
)
1532 mutex_lock(&sessions_mutex
);
1533 lttng_event_enabler_as_enabler(event_enabler
)->enabled
= 1;
1534 lttng_session_lazy_sync_event_enablers(event_enabler
->chan
->session
);
1535 mutex_unlock(&sessions_mutex
);
1539 int lttng_event_enabler_disable(struct lttng_event_enabler
*event_enabler
)
1541 mutex_lock(&sessions_mutex
);
1542 lttng_event_enabler_as_enabler(event_enabler
)->enabled
= 0;
1543 lttng_session_lazy_sync_event_enablers(event_enabler
->chan
->session
);
1544 mutex_unlock(&sessions_mutex
);
1549 int lttng_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
1550 struct lttng_kernel_filter_bytecode __user
*bytecode
)
1552 struct lttng_filter_bytecode_node
*bytecode_node
;
1553 uint32_t bytecode_len
;
1556 ret
= get_user(bytecode_len
, &bytecode
->len
);
1559 bytecode_node
= kzalloc(sizeof(*bytecode_node
) + bytecode_len
,
1563 ret
= copy_from_user(&bytecode_node
->bc
, bytecode
,
1564 sizeof(*bytecode
) + bytecode_len
);
1568 bytecode_node
->enabler
= enabler
;
1569 /* Enforce length based on allocated size */
1570 bytecode_node
->bc
.len
= bytecode_len
;
1571 list_add_tail(&bytecode_node
->node
, &enabler
->filter_bytecode_head
);
1576 kfree(bytecode_node
);
1580 int lttng_event_enabler_attach_bytecode(struct lttng_event_enabler
*event_enabler
,
1581 struct lttng_kernel_filter_bytecode __user
*bytecode
)
1584 ret
= lttng_enabler_attach_bytecode(
1585 lttng_event_enabler_as_enabler(event_enabler
), bytecode
);
1589 lttng_session_lazy_sync_event_enablers(event_enabler
->chan
->session
);
1596 int lttng_event_add_callsite(struct lttng_event
*event
,
1597 struct lttng_kernel_event_callsite __user
*callsite
)
1600 switch (event
->instrumentation
) {
1601 case LTTNG_KERNEL_UPROBE
:
1602 return lttng_uprobes_add_callsite(event
, callsite
);
1608 int lttng_event_enabler_attach_context(struct lttng_event_enabler
*event_enabler
,
1609 struct lttng_kernel_context
*context_param
)
1615 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
1617 struct lttng_filter_bytecode_node
*filter_node
, *tmp_filter_node
;
1619 /* Destroy filter bytecode */
1620 list_for_each_entry_safe(filter_node
, tmp_filter_node
,
1621 &enabler
->filter_bytecode_head
, node
) {
1627 void lttng_event_enabler_destroy(struct lttng_event_enabler
*event_enabler
)
1629 lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler
));
1631 /* Destroy contexts */
1632 lttng_destroy_context(event_enabler
->ctx
);
1634 list_del(&event_enabler
->node
);
1635 kfree(event_enabler
);
1639 * lttng_session_sync_event_enablers should be called just before starting a
1641 * Should be called with sessions mutex held.
1644 void lttng_session_sync_event_enablers(struct lttng_session
*session
)
1646 struct lttng_event_enabler
*event_enabler
;
1647 struct lttng_event
*event
;
1649 list_for_each_entry(event_enabler
, &session
->enablers_head
, node
)
1650 lttng_event_enabler_ref_events(event_enabler
);
1652 * For each event, if at least one of its enablers is enabled,
1653 * and its channel and session transient states are enabled, we
1654 * enable the event, else we disable it.
1656 list_for_each_entry(event
, &session
->events
, list
) {
1657 struct lttng_enabler_ref
*enabler_ref
;
1658 struct lttng_bytecode_runtime
*runtime
;
1659 int enabled
= 0, has_enablers_without_bytecode
= 0;
1661 switch (event
->instrumentation
) {
1662 case LTTNG_KERNEL_TRACEPOINT
:
1663 case LTTNG_KERNEL_SYSCALL
:
1665 list_for_each_entry(enabler_ref
,
1666 &event
->enablers_ref_head
, node
) {
1667 if (enabler_ref
->ref
->enabled
) {
1674 /* Not handled with lazy sync. */
1678 * Enabled state is based on union of enablers, with
1679 * intesection of session and channel transient enable
1682 enabled
= enabled
&& session
->tstate
&& event
->chan
->tstate
;
1684 WRITE_ONCE(event
->enabled
, enabled
);
1686 * Sync tracepoint registration with event enabled
1690 register_event(event
);
1692 _lttng_event_unregister(event
);
1695 /* Check if has enablers without bytecode enabled */
1696 list_for_each_entry(enabler_ref
,
1697 &event
->enablers_ref_head
, node
) {
1698 if (enabler_ref
->ref
->enabled
1699 && list_empty(&enabler_ref
->ref
->filter_bytecode_head
)) {
1700 has_enablers_without_bytecode
= 1;
1704 event
->has_enablers_without_bytecode
=
1705 has_enablers_without_bytecode
;
1707 /* Enable filters */
1708 list_for_each_entry(runtime
,
1709 &event
->bytecode_runtime_head
, node
)
1710 lttng_filter_sync_state(runtime
);
1715 * Apply enablers to session events, adding events to session if need
1716 * be. It is required after each modification applied to an active
1717 * session, and right before session "start".
1718 * "lazy" sync means we only sync if required.
1719 * Should be called with sessions mutex held.
1722 void lttng_session_lazy_sync_event_enablers(struct lttng_session
*session
)
1724 /* We can skip if session is not active */
1725 if (!session
->active
)
1727 lttng_session_sync_event_enablers(session
);
1731 * Serialize at most one packet worth of metadata into a metadata
1733 * We grab the metadata cache mutex to get exclusive access to our metadata
1734 * buffer and to the metadata cache. Exclusive access to the metadata buffer
1735 * allows us to do racy operations such as looking for remaining space left in
1736 * packet and write, since mutual exclusion protects us from concurrent writes.
1737 * Mutual exclusion on the metadata cache allow us to read the cache content
1738 * without racing against reallocation of the cache by updates.
1739 * Returns the number of bytes written in the channel, 0 if no data
1740 * was written and a negative value on error.
1742 int lttng_metadata_output_channel(struct lttng_metadata_stream
*stream
,
1743 struct channel
*chan
, bool *coherent
)
1745 struct lib_ring_buffer_ctx ctx
;
1747 size_t len
, reserve_len
;
1750 * Ensure we support mutiple get_next / put sequences followed by
1751 * put_next. The metadata cache lock protects reading the metadata
1752 * cache. It can indeed be read concurrently by "get_next_subbuf" and
1753 * "flush" operations on the buffer invoked by different processes.
1754 * Moreover, since the metadata cache memory can be reallocated, we
1755 * need to have exclusive access against updates even though we only
1758 mutex_lock(&stream
->metadata_cache
->lock
);
1759 WARN_ON(stream
->metadata_in
< stream
->metadata_out
);
1760 if (stream
->metadata_in
!= stream
->metadata_out
)
1763 /* Metadata regenerated, change the version. */
1764 if (stream
->metadata_cache
->version
!= stream
->version
)
1765 stream
->version
= stream
->metadata_cache
->version
;
1767 len
= stream
->metadata_cache
->metadata_written
-
1768 stream
->metadata_in
;
1771 reserve_len
= min_t(size_t,
1772 stream
->transport
->ops
.packet_avail_size(chan
),
1774 lib_ring_buffer_ctx_init(&ctx
, chan
, NULL
, reserve_len
,
1777 * If reservation failed, return an error to the caller.
1779 ret
= stream
->transport
->ops
.event_reserve(&ctx
, 0);
1781 printk(KERN_WARNING
"LTTng: Metadata event reservation failed\n");
1782 stream
->coherent
= false;
1785 stream
->transport
->ops
.event_write(&ctx
,
1786 stream
->metadata_cache
->data
+ stream
->metadata_in
,
1788 stream
->transport
->ops
.event_commit(&ctx
);
1789 stream
->metadata_in
+= reserve_len
;
1790 if (reserve_len
< len
)
1791 stream
->coherent
= false;
1793 stream
->coherent
= true;
1798 *coherent
= stream
->coherent
;
1799 mutex_unlock(&stream
->metadata_cache
->lock
);
1804 void lttng_metadata_begin(struct lttng_session
*session
)
1806 if (atomic_inc_return(&session
->metadata_cache
->producing
) == 1)
1807 mutex_lock(&session
->metadata_cache
->lock
);
1811 void lttng_metadata_end(struct lttng_session
*session
)
1813 WARN_ON_ONCE(!atomic_read(&session
->metadata_cache
->producing
));
1814 if (atomic_dec_return(&session
->metadata_cache
->producing
) == 0) {
1815 struct lttng_metadata_stream
*stream
;
1817 list_for_each_entry(stream
, &session
->metadata_cache
->metadata_stream
, list
)
1818 wake_up_interruptible(&stream
->read_wait
);
1819 mutex_unlock(&session
->metadata_cache
->lock
);
1824 * Write the metadata to the metadata cache.
1825 * Must be called with sessions_mutex held.
1826 * The metadata cache lock protects us from concurrent read access from
1827 * thread outputting metadata content to ring buffer.
1828 * The content of the printf is printed as a single atomic metadata
1831 int lttng_metadata_printf(struct lttng_session
*session
,
1832 const char *fmt
, ...)
1838 WARN_ON_ONCE(!LTTNG_READ_ONCE(session
->active
));
1841 str
= kvasprintf(GFP_KERNEL
, fmt
, ap
);
1847 WARN_ON_ONCE(!atomic_read(&session
->metadata_cache
->producing
));
1848 if (session
->metadata_cache
->metadata_written
+ len
>
1849 session
->metadata_cache
->cache_alloc
) {
1850 char *tmp_cache_realloc
;
1851 unsigned int tmp_cache_alloc_size
;
1853 tmp_cache_alloc_size
= max_t(unsigned int,
1854 session
->metadata_cache
->cache_alloc
+ len
,
1855 session
->metadata_cache
->cache_alloc
<< 1);
1856 tmp_cache_realloc
= vzalloc(tmp_cache_alloc_size
);
1857 if (!tmp_cache_realloc
)
1859 if (session
->metadata_cache
->data
) {
1860 memcpy(tmp_cache_realloc
,
1861 session
->metadata_cache
->data
,
1862 session
->metadata_cache
->cache_alloc
);
1863 vfree(session
->metadata_cache
->data
);
1866 session
->metadata_cache
->cache_alloc
= tmp_cache_alloc_size
;
1867 session
->metadata_cache
->data
= tmp_cache_realloc
;
1869 memcpy(session
->metadata_cache
->data
+
1870 session
->metadata_cache
->metadata_written
,
1872 session
->metadata_cache
->metadata_written
+= len
;
1883 int print_tabs(struct lttng_session
*session
, size_t nesting
)
1887 for (i
= 0; i
< nesting
; i
++) {
1890 ret
= lttng_metadata_printf(session
, " ");
1899 int lttng_field_name_statedump(struct lttng_session
*session
,
1900 const struct lttng_event_field
*field
,
1903 return lttng_metadata_printf(session
, " _%s;\n", field
->name
);
1907 int _lttng_integer_type_statedump(struct lttng_session
*session
,
1908 const struct lttng_type
*type
,
1913 WARN_ON_ONCE(type
->atype
!= atype_integer
);
1914 ret
= print_tabs(session
, nesting
);
1917 ret
= lttng_metadata_printf(session
,
1918 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s }",
1919 type
->u
.integer
.size
,
1920 type
->u
.integer
.alignment
,
1921 type
->u
.integer
.signedness
,
1922 (type
->u
.integer
.encoding
== lttng_encode_none
)
1924 : (type
->u
.integer
.encoding
== lttng_encode_UTF8
)
1927 type
->u
.integer
.base
,
1928 #if __BYTE_ORDER == __BIG_ENDIAN
1929 type
->u
.integer
.reverse_byte_order
? " byte_order = le;" : ""
1931 type
->u
.integer
.reverse_byte_order
? " byte_order = be;" : ""
1938 * Must be called with sessions_mutex held.
1941 int _lttng_struct_type_statedump(struct lttng_session
*session
,
1942 const struct lttng_type
*type
,
1946 uint32_t i
, nr_fields
;
1947 unsigned int alignment
;
1949 WARN_ON_ONCE(type
->atype
!= atype_struct_nestable
);
1951 ret
= print_tabs(session
, nesting
);
1954 ret
= lttng_metadata_printf(session
,
1958 nr_fields
= type
->u
.struct_nestable
.nr_fields
;
1959 for (i
= 0; i
< nr_fields
; i
++) {
1960 const struct lttng_event_field
*iter_field
;
1962 iter_field
= &type
->u
.struct_nestable
.fields
[i
];
1963 ret
= _lttng_field_statedump(session
, iter_field
, nesting
+ 1);
1967 ret
= print_tabs(session
, nesting
);
1970 alignment
= type
->u
.struct_nestable
.alignment
;
1972 ret
= lttng_metadata_printf(session
,
1976 ret
= lttng_metadata_printf(session
,
1983 * Must be called with sessions_mutex held.
1986 int _lttng_struct_field_statedump(struct lttng_session
*session
,
1987 const struct lttng_event_field
*field
,
1992 ret
= _lttng_struct_type_statedump(session
,
1993 &field
->type
, nesting
);
1996 return lttng_field_name_statedump(session
, field
, nesting
);
2000 * Must be called with sessions_mutex held.
2003 int _lttng_variant_type_statedump(struct lttng_session
*session
,
2004 const struct lttng_type
*type
,
2008 uint32_t i
, nr_choices
;
2010 WARN_ON_ONCE(type
->atype
!= atype_variant_nestable
);
2012 * CTF 1.8 does not allow expressing nonzero variant alignment in a nestable way.
2014 if (type
->u
.variant_nestable
.alignment
!= 0)
2016 ret
= print_tabs(session
, nesting
);
2019 ret
= lttng_metadata_printf(session
,
2020 "variant <_%s> {\n",
2021 type
->u
.variant_nestable
.tag_name
);
2024 nr_choices
= type
->u
.variant_nestable
.nr_choices
;
2025 for (i
= 0; i
< nr_choices
; i
++) {
2026 const struct lttng_event_field
*iter_field
;
2028 iter_field
= &type
->u
.variant_nestable
.choices
[i
];
2029 ret
= _lttng_field_statedump(session
, iter_field
, nesting
+ 1);
2033 ret
= print_tabs(session
, nesting
);
2036 ret
= lttng_metadata_printf(session
,
2042 * Must be called with sessions_mutex held.
2045 int _lttng_variant_field_statedump(struct lttng_session
*session
,
2046 const struct lttng_event_field
*field
,
2051 ret
= _lttng_variant_type_statedump(session
,
2052 &field
->type
, nesting
);
2055 return lttng_field_name_statedump(session
, field
, nesting
);
2059 * Must be called with sessions_mutex held.
2062 int _lttng_array_field_statedump(struct lttng_session
*session
,
2063 const struct lttng_event_field
*field
,
2067 const struct lttng_type
*elem_type
;
2069 WARN_ON_ONCE(field
->type
.atype
!= atype_array_nestable
);
2071 if (field
->type
.u
.array_nestable
.alignment
) {
2072 ret
= print_tabs(session
, nesting
);
2075 ret
= lttng_metadata_printf(session
,
2076 "struct { } align(%u) _%s_padding;\n",
2077 field
->type
.u
.array_nestable
.alignment
* CHAR_BIT
,
2083 * Nested compound types: Only array of structures and variants are
2084 * currently supported.
2086 elem_type
= field
->type
.u
.array_nestable
.elem_type
;
2087 switch (elem_type
->atype
) {
2089 case atype_struct_nestable
:
2090 case atype_variant_nestable
:
2091 ret
= _lttng_type_statedump(session
, elem_type
, nesting
);
2099 ret
= lttng_metadata_printf(session
,
2102 field
->type
.u
.array_nestable
.length
);
2107 * Must be called with sessions_mutex held.
2110 int _lttng_sequence_field_statedump(struct lttng_session
*session
,
2111 const struct lttng_event_field
*field
,
2115 const char *length_name
;
2116 const struct lttng_type
*elem_type
;
2118 WARN_ON_ONCE(field
->type
.atype
!= atype_sequence_nestable
);
2120 length_name
= field
->type
.u
.sequence_nestable
.length_name
;
2122 if (field
->type
.u
.sequence_nestable
.alignment
) {
2123 ret
= print_tabs(session
, nesting
);
2126 ret
= lttng_metadata_printf(session
,
2127 "struct { } align(%u) _%s_padding;\n",
2128 field
->type
.u
.sequence_nestable
.alignment
* CHAR_BIT
,
2135 * Nested compound types: Only array of structures and variants are
2136 * currently supported.
2138 elem_type
= field
->type
.u
.sequence_nestable
.elem_type
;
2139 switch (elem_type
->atype
) {
2141 case atype_struct_nestable
:
2142 case atype_variant_nestable
:
2143 ret
= _lttng_type_statedump(session
, elem_type
, nesting
);
2151 ret
= lttng_metadata_printf(session
,
2154 field
->type
.u
.sequence_nestable
.length_name
);
2159 * Must be called with sessions_mutex held.
2162 int _lttng_enum_type_statedump(struct lttng_session
*session
,
2163 const struct lttng_type
*type
,
2166 const struct lttng_enum_desc
*enum_desc
;
2167 const struct lttng_type
*container_type
;
2169 unsigned int i
, nr_entries
;
2171 container_type
= type
->u
.enum_nestable
.container_type
;
2172 if (container_type
->atype
!= atype_integer
) {
2176 enum_desc
= type
->u
.enum_nestable
.desc
;
2177 nr_entries
= enum_desc
->nr_entries
;
2179 ret
= print_tabs(session
, nesting
);
2182 ret
= lttng_metadata_printf(session
, "enum : ");
2185 ret
= _lttng_integer_type_statedump(session
, container_type
, 0);
2188 ret
= lttng_metadata_printf(session
, " {\n");
2191 /* Dump all entries */
2192 for (i
= 0; i
< nr_entries
; i
++) {
2193 const struct lttng_enum_entry
*entry
= &enum_desc
->entries
[i
];
2196 ret
= print_tabs(session
, nesting
+ 1);
2199 ret
= lttng_metadata_printf(session
,
2203 len
= strlen(entry
->string
);
2204 /* Escape the character '"' */
2205 for (j
= 0; j
< len
; j
++) {
2206 char c
= entry
->string
[j
];
2210 ret
= lttng_metadata_printf(session
,
2214 ret
= lttng_metadata_printf(session
,
2218 ret
= lttng_metadata_printf(session
,
2225 ret
= lttng_metadata_printf(session
, "\"");
2229 if (entry
->options
.is_auto
) {
2230 ret
= lttng_metadata_printf(session
, ",\n");
2234 ret
= lttng_metadata_printf(session
,
2238 if (entry
->start
.signedness
)
2239 ret
= lttng_metadata_printf(session
,
2240 "%lld", (long long) entry
->start
.value
);
2242 ret
= lttng_metadata_printf(session
,
2243 "%llu", entry
->start
.value
);
2246 if (entry
->start
.signedness
== entry
->end
.signedness
&&
2248 == entry
->end
.value
) {
2249 ret
= lttng_metadata_printf(session
,
2252 if (entry
->end
.signedness
) {
2253 ret
= lttng_metadata_printf(session
,
2255 (long long) entry
->end
.value
);
2257 ret
= lttng_metadata_printf(session
,
2266 ret
= print_tabs(session
, nesting
);
2269 ret
= lttng_metadata_printf(session
, "}");
2275 * Must be called with sessions_mutex held.
2278 int _lttng_enum_field_statedump(struct lttng_session
*session
,
2279 const struct lttng_event_field
*field
,
2284 ret
= _lttng_enum_type_statedump(session
, &field
->type
, nesting
);
2287 return lttng_field_name_statedump(session
, field
, nesting
);
2291 int _lttng_integer_field_statedump(struct lttng_session
*session
,
2292 const struct lttng_event_field
*field
,
2297 ret
= _lttng_integer_type_statedump(session
, &field
->type
, nesting
);
2300 return lttng_field_name_statedump(session
, field
, nesting
);
2304 int _lttng_string_type_statedump(struct lttng_session
*session
,
2305 const struct lttng_type
*type
,
2310 WARN_ON_ONCE(type
->atype
!= atype_string
);
2311 /* Default encoding is UTF8 */
2312 ret
= print_tabs(session
, nesting
);
2315 ret
= lttng_metadata_printf(session
,
2317 type
->u
.string
.encoding
== lttng_encode_ASCII
?
2318 " { encoding = ASCII; }" : "");
2323 int _lttng_string_field_statedump(struct lttng_session
*session
,
2324 const struct lttng_event_field
*field
,
2329 WARN_ON_ONCE(field
->type
.atype
!= atype_string
);
2330 ret
= _lttng_string_type_statedump(session
, &field
->type
, nesting
);
2333 return lttng_field_name_statedump(session
, field
, nesting
);
2337 * Must be called with sessions_mutex held.
2340 int _lttng_type_statedump(struct lttng_session
*session
,
2341 const struct lttng_type
*type
,
2346 switch (type
->atype
) {
2348 ret
= _lttng_integer_type_statedump(session
, type
, nesting
);
2350 case atype_enum_nestable
:
2351 ret
= _lttng_enum_type_statedump(session
, type
, nesting
);
2354 ret
= _lttng_string_type_statedump(session
, type
, nesting
);
2356 case atype_struct_nestable
:
2357 ret
= _lttng_struct_type_statedump(session
, type
, nesting
);
2359 case atype_variant_nestable
:
2360 ret
= _lttng_variant_type_statedump(session
, type
, nesting
);
2363 /* Nested arrays and sequences are not supported yet. */
2364 case atype_array_nestable
:
2365 case atype_sequence_nestable
:
2374 * Must be called with sessions_mutex held.
2377 int _lttng_field_statedump(struct lttng_session
*session
,
2378 const struct lttng_event_field
*field
,
2383 switch (field
->type
.atype
) {
2385 ret
= _lttng_integer_field_statedump(session
, field
, nesting
);
2387 case atype_enum_nestable
:
2388 ret
= _lttng_enum_field_statedump(session
, field
, nesting
);
2391 ret
= _lttng_string_field_statedump(session
, field
, nesting
);
2393 case atype_struct_nestable
:
2394 ret
= _lttng_struct_field_statedump(session
, field
, nesting
);
2396 case atype_array_nestable
:
2397 ret
= _lttng_array_field_statedump(session
, field
, nesting
);
2399 case atype_sequence_nestable
:
2400 ret
= _lttng_sequence_field_statedump(session
, field
, nesting
);
2402 case atype_variant_nestable
:
2403 ret
= _lttng_variant_field_statedump(session
, field
, nesting
);
2414 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
2415 struct lttng_ctx
*ctx
)
2422 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
2423 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
2425 ret
= _lttng_field_statedump(session
, &field
->event_field
, 2);
2433 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
2434 struct lttng_event
*event
)
2436 const struct lttng_event_desc
*desc
= event
->desc
;
2440 for (i
= 0; i
< desc
->nr_fields
; i
++) {
2441 const struct lttng_event_field
*field
= &desc
->fields
[i
];
2443 ret
= _lttng_field_statedump(session
, field
, 2);
2451 * Must be called with sessions_mutex held.
2452 * The entire event metadata is printed as a single atomic metadata
2456 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
2457 struct lttng_channel
*chan
,
2458 struct lttng_event
*event
)
2462 if (event
->metadata_dumped
|| !LTTNG_READ_ONCE(session
->active
))
2464 if (chan
->channel_type
== METADATA_CHANNEL
)
2467 lttng_metadata_begin(session
);
2469 ret
= lttng_metadata_printf(session
,
2473 " stream_id = %u;\n",
2481 ret
= lttng_metadata_printf(session
,
2482 " context := struct {\n");
2486 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
2490 ret
= lttng_metadata_printf(session
,
2496 ret
= lttng_metadata_printf(session
,
2497 " fields := struct {\n"
2502 ret
= _lttng_fields_metadata_statedump(session
, event
);
2507 * LTTng space reservation can only reserve multiples of the
2510 ret
= lttng_metadata_printf(session
,
2516 event
->metadata_dumped
= 1;
2518 lttng_metadata_end(session
);
2524 * Must be called with sessions_mutex held.
2525 * The entire channel metadata is printed as a single atomic metadata
2529 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
2530 struct lttng_channel
*chan
)
2534 if (chan
->metadata_dumped
|| !LTTNG_READ_ONCE(session
->active
))
2537 if (chan
->channel_type
== METADATA_CHANNEL
)
2540 lttng_metadata_begin(session
);
2542 WARN_ON_ONCE(!chan
->header_type
);
2543 ret
= lttng_metadata_printf(session
,
2546 " event.header := %s;\n"
2547 " packet.context := struct packet_context;\n",
2549 chan
->header_type
== 1 ? "struct event_header_compact" :
2550 "struct event_header_large");
2555 ret
= lttng_metadata_printf(session
,
2556 " event.context := struct {\n");
2560 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
2564 ret
= lttng_metadata_printf(session
,
2570 ret
= lttng_metadata_printf(session
,
2573 chan
->metadata_dumped
= 1;
2575 lttng_metadata_end(session
);
2580 * Must be called with sessions_mutex held.
2583 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
2585 return lttng_metadata_printf(session
,
2586 "struct packet_context {\n"
2587 " uint64_clock_monotonic_t timestamp_begin;\n"
2588 " uint64_clock_monotonic_t timestamp_end;\n"
2589 " uint64_t content_size;\n"
2590 " uint64_t packet_size;\n"
2591 " uint64_t packet_seq_num;\n"
2592 " unsigned long events_discarded;\n"
2593 " uint32_t cpu_id;\n"
2600 * id: range: 0 - 30.
2601 * id 31 is reserved to indicate an extended header.
2604 * id: range: 0 - 65534.
2605 * id 65535 is reserved to indicate an extended header.
2607 * Must be called with sessions_mutex held.
2610 int _lttng_event_header_declare(struct lttng_session
*session
)
2612 return lttng_metadata_printf(session
,
2613 "struct event_header_compact {\n"
2614 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
2617 " uint27_clock_monotonic_t timestamp;\n"
2621 " uint64_clock_monotonic_t timestamp;\n"
2626 "struct event_header_large {\n"
2627 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
2630 " uint32_clock_monotonic_t timestamp;\n"
2634 " uint64_clock_monotonic_t timestamp;\n"
2638 lttng_alignof(uint32_t) * CHAR_BIT
,
2639 lttng_alignof(uint16_t) * CHAR_BIT
2644 * Approximation of NTP time of day to clock monotonic correlation,
2645 * taken at start of trace.
2646 * Yes, this is only an approximation. Yes, we can (and will) do better
2647 * in future versions.
2648 * This function may return a negative offset. It may happen if the
2649 * system sets the REALTIME clock to 0 after boot.
2651 * Use 64bit timespec on kernels that have it, this makes 32bit arch
2655 int64_t measure_clock_offset(void)
2657 uint64_t monotonic_avg
, monotonic
[2], realtime
;
2658 uint64_t tcf
= trace_clock_freq();
2660 unsigned long flags
;
2661 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
2662 struct timespec64 rts
= { 0, 0 };
2664 struct timespec rts
= { 0, 0 };
2667 /* Disable interrupts to increase correlation precision. */
2668 local_irq_save(flags
);
2669 monotonic
[0] = trace_clock_read64();
2670 #ifdef LTTNG_KERNEL_HAS_TIMESPEC64
2671 ktime_get_real_ts64(&rts
);
2673 getnstimeofday(&rts
);
2675 monotonic
[1] = trace_clock_read64();
2676 local_irq_restore(flags
);
2678 monotonic_avg
= (monotonic
[0] + monotonic
[1]) >> 1;
2679 realtime
= (uint64_t) rts
.tv_sec
* tcf
;
2680 if (tcf
== NSEC_PER_SEC
) {
2681 realtime
+= rts
.tv_nsec
;
2683 uint64_t n
= rts
.tv_nsec
* tcf
;
2685 do_div(n
, NSEC_PER_SEC
);
2688 offset
= (int64_t) realtime
- monotonic_avg
;
2693 int print_escaped_ctf_string(struct lttng_session
*session
, const char *string
)
2701 while (cur
!= '\0') {
2704 ret
= lttng_metadata_printf(session
, "%s", "\\n");
2708 ret
= lttng_metadata_printf(session
, "%c", '\\');
2711 /* We still print the current char */
2714 ret
= lttng_metadata_printf(session
, "%c", cur
);
2728 int print_metadata_escaped_field(struct lttng_session
*session
, const char *field
,
2729 const char *field_value
)
2733 ret
= lttng_metadata_printf(session
, " %s = \"", field
);
2737 ret
= print_escaped_ctf_string(session
, field_value
);
2741 ret
= lttng_metadata_printf(session
, "\";\n");
2748 * Output metadata into this session's metadata buffers.
2749 * Must be called with sessions_mutex held.
2752 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
2754 unsigned char *uuid_c
= session
->uuid
.b
;
2755 unsigned char uuid_s
[37], clock_uuid_s
[BOOT_ID_LEN
];
2756 const char *product_uuid
;
2757 struct lttng_channel
*chan
;
2758 struct lttng_event
*event
;
2761 if (!LTTNG_READ_ONCE(session
->active
))
2764 lttng_metadata_begin(session
);
2766 if (session
->metadata_dumped
)
2769 snprintf(uuid_s
, sizeof(uuid_s
),
2770 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
2771 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
2772 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
2773 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
2774 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
2776 ret
= lttng_metadata_printf(session
,
2777 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
2778 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
2779 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
2780 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
2781 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
2782 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
2783 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
2789 " byte_order = %s;\n"
2790 " packet.header := struct {\n"
2791 " uint32_t magic;\n"
2792 " uint8_t uuid[16];\n"
2793 " uint32_t stream_id;\n"
2794 " uint64_t stream_instance_id;\n"
2797 lttng_alignof(uint8_t) * CHAR_BIT
,
2798 lttng_alignof(uint16_t) * CHAR_BIT
,
2799 lttng_alignof(uint32_t) * CHAR_BIT
,
2800 lttng_alignof(uint64_t) * CHAR_BIT
,
2801 sizeof(unsigned long) * CHAR_BIT
,
2802 lttng_alignof(unsigned long) * CHAR_BIT
,
2806 #if __BYTE_ORDER == __BIG_ENDIAN
2815 ret
= lttng_metadata_printf(session
,
2817 " hostname = \"%s\";\n"
2818 " domain = \"kernel\";\n"
2819 " sysname = \"%s\";\n"
2820 " kernel_release = \"%s\";\n"
2821 " kernel_version = \"%s\";\n"
2822 " tracer_name = \"lttng-modules\";\n"
2823 " tracer_major = %d;\n"
2824 " tracer_minor = %d;\n"
2825 " tracer_patchlevel = %d;\n"
2826 " trace_buffering_scheme = \"global\";\n",
2827 current
->nsproxy
->uts_ns
->name
.nodename
,
2831 LTTNG_MODULES_MAJOR_VERSION
,
2832 LTTNG_MODULES_MINOR_VERSION
,
2833 LTTNG_MODULES_PATCHLEVEL_VERSION
2838 ret
= print_metadata_escaped_field(session
, "trace_name", session
->name
);
2841 ret
= print_metadata_escaped_field(session
, "trace_creation_datetime",
2842 session
->creation_time
);
2846 /* Add the product UUID to the 'env' section */
2847 product_uuid
= dmi_get_system_info(DMI_PRODUCT_UUID
);
2849 ret
= lttng_metadata_printf(session
,
2850 " product_uuid = \"%s\";\n",
2857 /* Close the 'env' section */
2858 ret
= lttng_metadata_printf(session
, "};\n\n");
2862 ret
= lttng_metadata_printf(session
,
2864 " name = \"%s\";\n",
2870 if (!trace_clock_uuid(clock_uuid_s
)) {
2871 ret
= lttng_metadata_printf(session
,
2872 " uuid = \"%s\";\n",
2879 ret
= lttng_metadata_printf(session
,
2880 " description = \"%s\";\n"
2881 " freq = %llu; /* Frequency, in Hz */\n"
2882 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
2885 trace_clock_description(),
2886 (unsigned long long) trace_clock_freq(),
2887 (long long) measure_clock_offset()
2892 ret
= lttng_metadata_printf(session
,
2893 "typealias integer {\n"
2894 " size = 27; align = 1; signed = false;\n"
2895 " map = clock.%s.value;\n"
2896 "} := uint27_clock_monotonic_t;\n"
2898 "typealias integer {\n"
2899 " size = 32; align = %u; signed = false;\n"
2900 " map = clock.%s.value;\n"
2901 "} := uint32_clock_monotonic_t;\n"
2903 "typealias integer {\n"
2904 " size = 64; align = %u; signed = false;\n"
2905 " map = clock.%s.value;\n"
2906 "} := uint64_clock_monotonic_t;\n\n",
2908 lttng_alignof(uint32_t) * CHAR_BIT
,
2910 lttng_alignof(uint64_t) * CHAR_BIT
,
2916 ret
= _lttng_stream_packet_context_declare(session
);
2920 ret
= _lttng_event_header_declare(session
);
2925 list_for_each_entry(chan
, &session
->chan
, list
) {
2926 ret
= _lttng_channel_metadata_statedump(session
, chan
);
2931 list_for_each_entry(event
, &session
->events
, list
) {
2932 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
2936 session
->metadata_dumped
= 1;
2938 lttng_metadata_end(session
);
2943 * lttng_transport_register - LTT transport registration
2944 * @transport: transport structure
2946 * Registers a transport which can be used as output to extract the data out of
2947 * LTTng. The module calling this registration function must ensure that no
2948 * trap-inducing code will be executed by the transport functions. E.g.
2949 * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory
2950 * is made visible to the transport function. This registration acts as a
2951 * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory
2952 * after its registration must it synchronize the TLBs.
2954 void lttng_transport_register(struct lttng_transport
*transport
)
2957 * Make sure no page fault can be triggered by the module about to be
2958 * registered. We deal with this here so we don't have to call
2959 * vmalloc_sync_mappings() in each module's init.
2961 wrapper_vmalloc_sync_mappings();
2963 mutex_lock(&sessions_mutex
);
2964 list_add_tail(&transport
->node
, <tng_transport_list
);
2965 mutex_unlock(&sessions_mutex
);
2967 EXPORT_SYMBOL_GPL(lttng_transport_register
);
2970 * lttng_transport_unregister - LTT transport unregistration
2971 * @transport: transport structure
2973 void lttng_transport_unregister(struct lttng_transport
*transport
)
2975 mutex_lock(&sessions_mutex
);
2976 list_del(&transport
->node
);
2977 mutex_unlock(&sessions_mutex
);
2979 EXPORT_SYMBOL_GPL(lttng_transport_unregister
);
2981 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
2983 enum cpuhp_state lttng_hp_prepare
;
2984 enum cpuhp_state lttng_hp_online
;
2986 static int lttng_hotplug_prepare(unsigned int cpu
, struct hlist_node
*node
)
2988 struct lttng_cpuhp_node
*lttng_node
;
2990 lttng_node
= container_of(node
, struct lttng_cpuhp_node
, node
);
2991 switch (lttng_node
->component
) {
2992 case LTTNG_RING_BUFFER_FRONTEND
:
2994 case LTTNG_RING_BUFFER_BACKEND
:
2995 return lttng_cpuhp_rb_backend_prepare(cpu
, lttng_node
);
2996 case LTTNG_RING_BUFFER_ITER
:
2998 case LTTNG_CONTEXT_PERF_COUNTERS
:
3005 static int lttng_hotplug_dead(unsigned int cpu
, struct hlist_node
*node
)
3007 struct lttng_cpuhp_node
*lttng_node
;
3009 lttng_node
= container_of(node
, struct lttng_cpuhp_node
, node
);
3010 switch (lttng_node
->component
) {
3011 case LTTNG_RING_BUFFER_FRONTEND
:
3012 return lttng_cpuhp_rb_frontend_dead(cpu
, lttng_node
);
3013 case LTTNG_RING_BUFFER_BACKEND
:
3015 case LTTNG_RING_BUFFER_ITER
:
3017 case LTTNG_CONTEXT_PERF_COUNTERS
:
3018 return lttng_cpuhp_perf_counter_dead(cpu
, lttng_node
);
3024 static int lttng_hotplug_online(unsigned int cpu
, struct hlist_node
*node
)
3026 struct lttng_cpuhp_node
*lttng_node
;
3028 lttng_node
= container_of(node
, struct lttng_cpuhp_node
, node
);
3029 switch (lttng_node
->component
) {
3030 case LTTNG_RING_BUFFER_FRONTEND
:
3031 return lttng_cpuhp_rb_frontend_online(cpu
, lttng_node
);
3032 case LTTNG_RING_BUFFER_BACKEND
:
3034 case LTTNG_RING_BUFFER_ITER
:
3035 return lttng_cpuhp_rb_iter_online(cpu
, lttng_node
);
3036 case LTTNG_CONTEXT_PERF_COUNTERS
:
3037 return lttng_cpuhp_perf_counter_online(cpu
, lttng_node
);
3043 static int lttng_hotplug_offline(unsigned int cpu
, struct hlist_node
*node
)
3045 struct lttng_cpuhp_node
*lttng_node
;
3047 lttng_node
= container_of(node
, struct lttng_cpuhp_node
, node
);
3048 switch (lttng_node
->component
) {
3049 case LTTNG_RING_BUFFER_FRONTEND
:
3050 return lttng_cpuhp_rb_frontend_offline(cpu
, lttng_node
);
3051 case LTTNG_RING_BUFFER_BACKEND
:
3053 case LTTNG_RING_BUFFER_ITER
:
3055 case LTTNG_CONTEXT_PERF_COUNTERS
:
3062 static int __init
lttng_init_cpu_hotplug(void)
3066 ret
= cpuhp_setup_state_multi(CPUHP_BP_PREPARE_DYN
, "lttng:prepare",
3067 lttng_hotplug_prepare
,
3068 lttng_hotplug_dead
);
3072 lttng_hp_prepare
= ret
;
3073 lttng_rb_set_hp_prepare(ret
);
3075 ret
= cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN
, "lttng:online",
3076 lttng_hotplug_online
,
3077 lttng_hotplug_offline
);
3079 cpuhp_remove_multi_state(lttng_hp_prepare
);
3080 lttng_hp_prepare
= 0;
3083 lttng_hp_online
= ret
;
3084 lttng_rb_set_hp_online(ret
);
3089 static void __exit
lttng_exit_cpu_hotplug(void)
3091 lttng_rb_set_hp_online(0);
3092 cpuhp_remove_multi_state(lttng_hp_online
);
3093 lttng_rb_set_hp_prepare(0);
3094 cpuhp_remove_multi_state(lttng_hp_prepare
);
3097 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
3098 static int lttng_init_cpu_hotplug(void)
3102 static void lttng_exit_cpu_hotplug(void)
3105 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
3108 static int __init
lttng_events_init(void)
3112 ret
= wrapper_lttng_fixup_sig(THIS_MODULE
);
3115 ret
= wrapper_get_pfnblock_flags_mask_init();
3118 ret
= wrapper_get_pageblock_flags_mask_init();
3121 ret
= lttng_probes_init();
3124 ret
= lttng_context_init();
3127 ret
= lttng_tracepoint_init();
3130 event_cache
= KMEM_CACHE(lttng_event
, 0);
3135 ret
= lttng_abi_init();
3138 ret
= lttng_logger_init();
3141 ret
= lttng_init_cpu_hotplug();
3144 printk(KERN_NOTICE
"LTTng: Loaded modules v%s.%s.%s%s (%s)%s%s\n",
3145 __stringify(LTTNG_MODULES_MAJOR_VERSION
),
3146 __stringify(LTTNG_MODULES_MINOR_VERSION
),
3147 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION
),
3148 LTTNG_MODULES_EXTRAVERSION
,
3150 #ifdef LTTNG_EXTRA_VERSION_GIT
3151 LTTNG_EXTRA_VERSION_GIT
[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT
,
3155 #ifdef LTTNG_EXTRA_VERSION_NAME
3156 LTTNG_EXTRA_VERSION_NAME
[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME
);
3163 lttng_logger_exit();
3167 kmem_cache_destroy(event_cache
);
3169 lttng_tracepoint_exit();
3171 lttng_context_exit();
3172 printk(KERN_NOTICE
"LTTng: Failed to load modules v%s.%s.%s%s (%s)%s%s\n",
3173 __stringify(LTTNG_MODULES_MAJOR_VERSION
),
3174 __stringify(LTTNG_MODULES_MINOR_VERSION
),
3175 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION
),
3176 LTTNG_MODULES_EXTRAVERSION
,
3178 #ifdef LTTNG_EXTRA_VERSION_GIT
3179 LTTNG_EXTRA_VERSION_GIT
[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT
,
3183 #ifdef LTTNG_EXTRA_VERSION_NAME
3184 LTTNG_EXTRA_VERSION_NAME
[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME
);
3191 module_init(lttng_events_init
);
3193 static void __exit
lttng_events_exit(void)
3195 struct lttng_session
*session
, *tmpsession
;
3197 lttng_exit_cpu_hotplug();
3198 lttng_logger_exit();
3200 list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
3201 lttng_session_destroy(session
);
3202 kmem_cache_destroy(event_cache
);
3203 lttng_tracepoint_exit();
3204 lttng_context_exit();
3205 printk(KERN_NOTICE
"LTTng: Unloaded modules v%s.%s.%s%s (%s)%s%s\n",
3206 __stringify(LTTNG_MODULES_MAJOR_VERSION
),
3207 __stringify(LTTNG_MODULES_MINOR_VERSION
),
3208 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION
),
3209 LTTNG_MODULES_EXTRAVERSION
,
3211 #ifdef LTTNG_EXTRA_VERSION_GIT
3212 LTTNG_EXTRA_VERSION_GIT
[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_GIT
,
3216 #ifdef LTTNG_EXTRA_VERSION_NAME
3217 LTTNG_EXTRA_VERSION_NAME
[0] == '\0' ? "" : " - " LTTNG_EXTRA_VERSION_NAME
);
3223 module_exit(lttng_events_exit
);
3225 #include <generated/patches.h>
3226 #ifdef LTTNG_EXTRA_VERSION_GIT
3227 MODULE_INFO(extra_version_git
, LTTNG_EXTRA_VERSION_GIT
);
3229 #ifdef LTTNG_EXTRA_VERSION_NAME
3230 MODULE_INFO(extra_version_name
, LTTNG_EXTRA_VERSION_NAME
);
3232 MODULE_LICENSE("GPL and additional rights");
3233 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
3234 MODULE_DESCRIPTION("LTTng tracer");
3235 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION
) "."
3236 __stringify(LTTNG_MODULES_MINOR_VERSION
) "."
3237 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION
)
3238 LTTNG_MODULES_EXTRAVERSION
);