1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
3 * lttng-context-pid-ns.c
5 * LTTng pid namespace context.
7 * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 * 2019 Michael Jeanson <mjeanson@efficios.com>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/sched.h>
15 #include <linux/pid_namespace.h>
16 #include <lttng/events.h>
17 #include <lttng/events-internal.h>
18 #include <ringbuffer/frontend_types.h>
19 #include <wrapper/vmalloc.h>
20 #include <wrapper/namespace.h>
21 #include <lttng/tracer.h>
23 #if defined(CONFIG_PID_NS) && \
24 (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,8,0))
27 size_t pid_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 pid_ns_record(void *priv
, struct lttng_kernel_probe_ctx
*probe_ctx
,
38 struct lttng_kernel_ring_buffer_ctx
*ctx
,
39 struct lttng_kernel_channel_buffer
*chan
)
41 struct pid_namespace
*ns
;
42 unsigned int pid_ns_inum
= 0;
45 * The pid namespace is an exception -- it's accessed using
46 * task_active_pid_ns. The pid namespace in nsproxy is the
47 * namespace that children will use.
49 ns
= task_active_pid_ns(current
);
52 pid_ns_inum
= ns
->lttng_ns_inum
;
54 chan
->ops
->event_write(ctx
, &pid_ns_inum
, sizeof(pid_ns_inum
), lttng_alignof(pid_ns_inum
));
58 void pid_ns_get_value(void *priv
,
59 struct lttng_kernel_probe_ctx
*lttng_probe_ctx
,
60 struct lttng_ctx_value
*value
)
62 struct pid_namespace
*ns
;
63 unsigned int pid_ns_inum
= 0;
66 * The pid namespace is an exception -- it's accessed using
67 * task_active_pid_ns. The pid namespace in nsproxy is the
68 * namespace that children will use.
70 ns
= task_active_pid_ns(current
);
73 pid_ns_inum
= ns
->lttng_ns_inum
;
75 value
->u
.s64
= pid_ns_inum
;
78 static const struct lttng_kernel_ctx_field
*ctx_field
= lttng_kernel_static_ctx_field(
79 lttng_kernel_static_event_field("pid_ns",
80 lttng_kernel_static_type_integer_from_type(unsigned int, __BYTE_ORDER
, 10),
87 int lttng_add_pid_ns_to_ctx(struct lttng_kernel_ctx
**ctx
)
91 if (lttng_kernel_find_context(*ctx
, ctx_field
->event_field
->name
))
93 ret
= lttng_kernel_context_append(ctx
, ctx_field
);
94 wrapper_vmalloc_sync_mappings();
97 EXPORT_SYMBOL_GPL(lttng_add_pid_ns_to_ctx
);