Commit | Line | Data |
---|---|---|
b7cdc182 | 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
a6cf40a4 MJ |
2 | * |
3 | * lttng-context-pid-ns.c | |
4 | * | |
5 | * LTTng pid namespace context. | |
6 | * | |
7 | * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
8 | * 2019 Michael Jeanson <mjeanson@efficios.com> | |
9 | * | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/pid_namespace.h> | |
2df37e95 | 16 | #include <lttng/events.h> |
437d5aa5 | 17 | #include <lttng/events-internal.h> |
24591303 | 18 | #include <ringbuffer/frontend_types.h> |
a6cf40a4 MJ |
19 | #include <wrapper/vmalloc.h> |
20 | #include <wrapper/namespace.h> | |
2df37e95 | 21 | #include <lttng/tracer.h> |
a6cf40a4 MJ |
22 | |
23 | #if defined(CONFIG_PID_NS) && \ | |
5f4c791e | 24 | (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,8,0)) |
a6cf40a4 MJ |
25 | |
26 | static | |
346cb5ee | 27 | size_t pid_ns_get_size(void *priv, struct lttng_kernel_probe_ctx *probe_ctx, size_t offset) |
a6cf40a4 MJ |
28 | { |
29 | size_t size = 0; | |
30 | ||
31 | size += lib_ring_buffer_align(offset, lttng_alignof(unsigned int)); | |
32 | size += sizeof(unsigned int); | |
33 | return size; | |
34 | } | |
35 | ||
36 | static | |
346cb5ee | 37 | void pid_ns_record(void *priv, struct lttng_kernel_probe_ctx *probe_ctx, |
e27e4381 | 38 | struct lttng_kernel_ring_buffer_ctx *ctx, |
ac847066 | 39 | struct lttng_kernel_channel_buffer *chan) |
a6cf40a4 MJ |
40 | { |
41 | struct pid_namespace *ns; | |
42 | unsigned int pid_ns_inum = 0; | |
43 | ||
44 | /* | |
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. | |
48 | */ | |
49 | ns = task_active_pid_ns(current); | |
50 | ||
51 | if (ns) | |
52 | pid_ns_inum = ns->lttng_ns_inum; | |
53 | ||
77fcffef | 54 | chan->ops->event_write(ctx, &pid_ns_inum, sizeof(pid_ns_inum), lttng_alignof(pid_ns_inum)); |
a6cf40a4 MJ |
55 | } |
56 | ||
57 | static | |
ea2d95e4 | 58 | void pid_ns_get_value(void *priv, |
346cb5ee | 59 | struct lttng_kernel_probe_ctx *lttng_probe_ctx, |
ea2d95e4 | 60 | struct lttng_ctx_value *value) |
a6cf40a4 MJ |
61 | { |
62 | struct pid_namespace *ns; | |
63 | unsigned int pid_ns_inum = 0; | |
64 | ||
65 | /* | |
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. | |
69 | */ | |
70 | ns = task_active_pid_ns(current); | |
71 | ||
72 | if (ns) | |
73 | pid_ns_inum = ns->lttng_ns_inum; | |
74 | ||
ea2d95e4 | 75 | value->u.s64 = pid_ns_inum; |
a6cf40a4 MJ |
76 | } |
77 | ||
437d5aa5 MD |
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), | |
81 | false, false, false), | |
82 | pid_ns_get_size, | |
437d5aa5 MD |
83 | pid_ns_record, |
84 | pid_ns_get_value, | |
85 | NULL, NULL); | |
86 | ||
87 | int lttng_add_pid_ns_to_ctx(struct lttng_kernel_ctx **ctx) | |
a6cf40a4 | 88 | { |
437d5aa5 | 89 | int ret; |
a6cf40a4 | 90 | |
437d5aa5 | 91 | if (lttng_kernel_find_context(*ctx, ctx_field->event_field->name)) |
a6cf40a4 | 92 | return -EEXIST; |
437d5aa5 | 93 | ret = lttng_kernel_context_append(ctx, ctx_field); |
263b6c88 | 94 | wrapper_vmalloc_sync_mappings(); |
437d5aa5 | 95 | return ret; |
a6cf40a4 MJ |
96 | } |
97 | EXPORT_SYMBOL_GPL(lttng_add_pid_ns_to_ctx); | |
98 | ||
99 | #endif |