1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
3 * lttng-context-time-ns.c
5 * LTTng time namespace context.
7 * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 * 2020 Michael Jeanson <mjeanson@efficios.com>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/sched.h>
15 #include <linux/nsproxy.h>
16 #include <linux/time_namespace.h>
17 #include <lttng/events.h>
18 #include <lttng/events-internal.h>
19 #include <ringbuffer/frontend_types.h>
20 #include <wrapper/vmalloc.h>
21 #include <wrapper/namespace.h>
22 #include <lttng/tracer.h>
24 #if defined(CONFIG_TIME_NS)
27 size_t time_ns_get_size(void *priv
, struct lttng_kernel_probe_ctx
*probe_ctx
, size_t offset
)
31 size
+= lib_ring_buffer_align(offset
, lttng_alignof(unsigned int));
32 size
+= sizeof(unsigned int);
37 void time_ns_record(void *priv
, struct lttng_kernel_probe_ctx
*probe_ctx
,
38 struct lttng_kernel_ring_buffer_ctx
*ctx
,
39 struct lttng_channel
*chan
)
41 unsigned int time_ns_inum
= 0;
44 * nsproxy can be NULL when scheduled out of exit.
46 * As documented in 'linux/nsproxy.h' namespaces access rules, no
47 * precautions should be taken when accessing the current task's
48 * namespaces, just dereference the pointers.
51 time_ns_inum
= current
->nsproxy
->time_ns
->lttng_ns_inum
;
53 lib_ring_buffer_align_ctx(ctx
, lttng_alignof(time_ns_inum
));
54 chan
->ops
->event_write(ctx
, &time_ns_inum
, sizeof(time_ns_inum
));
58 void time_ns_get_value(void *priv
,
59 struct lttng_kernel_probe_ctx
*lttng_probe_ctx
,
60 struct lttng_ctx_value
*value
)
62 unsigned int time_ns_inum
= 0;
65 * nsproxy can be NULL when scheduled out of exit.
67 * As documented in 'linux/nsproxy.h' namespaces access rules, no
68 * precautions should be taken when accessing the current task's
69 * namespaces, just dereference the pointers.
72 time_ns_inum
= current
->nsproxy
->time_ns
->lttng_ns_inum
;
74 value
->u
.s64
= time_ns_inum
;
77 static const struct lttng_kernel_ctx_field
*ctx_field
= lttng_kernel_static_ctx_field(
78 lttng_kernel_static_event_field("time_ns",
79 lttng_kernel_static_type_integer_from_type(unsigned int, __BYTE_ORDER
, 10),
86 int lttng_add_time_ns_to_ctx(struct lttng_kernel_ctx
**ctx
)
90 if (lttng_kernel_find_context(*ctx
, ctx_field
->event_field
->name
))
92 ret
= lttng_kernel_context_append(ctx
, ctx_field
);
93 wrapper_vmalloc_sync_mappings();
96 EXPORT_SYMBOL_GPL(lttng_add_time_ns_to_ctx
);