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b7cdc182 | 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
a6cf40a4 MJ |
2 | * |
3 | * lttng-context-user-ns.c | |
4 | * | |
5 | * LTTng user 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/user_namespace.h> | |
2df37e95 | 16 | #include <lttng/events.h> |
437d5aa5 | 17 | #include <lttng/events-internal.h> |
24591303 | 18 | #include <ringbuffer/frontend_types.h> |
a6cf40a4 | 19 | #include <wrapper/vmalloc.h> |
2df37e95 | 20 | #include <lttng/tracer.h> |
a6cf40a4 MJ |
21 | |
22 | #if defined(CONFIG_USER_NS) && \ | |
5f4c791e | 23 | (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,8,0)) |
a6cf40a4 MJ |
24 | |
25 | static | |
a92e844e | 26 | size_t user_ns_get_size(void *priv, struct lttng_kernel_probe_ctx *probe_ctx, size_t offset) |
a6cf40a4 MJ |
27 | { |
28 | size_t size = 0; | |
29 | ||
30 | size += lib_ring_buffer_align(offset, lttng_alignof(unsigned int)); | |
31 | size += sizeof(unsigned int); | |
32 | return size; | |
33 | } | |
34 | ||
35 | static | |
a92e844e | 36 | void user_ns_record(void *priv, struct lttng_kernel_probe_ctx *probe_ctx, |
8a57ec02 | 37 | struct lttng_kernel_ring_buffer_ctx *ctx, |
f7d06400 | 38 | struct lttng_kernel_channel_buffer *chan) |
a6cf40a4 MJ |
39 | { |
40 | unsigned int user_ns_inum = 0; | |
41 | ||
42 | if (current_user_ns()) | |
93e5bcec | 43 | user_ns_inum = current_user_ns()->ns.inum; |
a6cf40a4 | 44 | |
f5ffbd77 | 45 | chan->ops->event_write(ctx, &user_ns_inum, sizeof(user_ns_inum), lttng_alignof(user_ns_inum)); |
a6cf40a4 MJ |
46 | } |
47 | ||
48 | static | |
2dc781e0 | 49 | void user_ns_get_value(void *priv, |
a92e844e | 50 | struct lttng_kernel_probe_ctx *lttng_probe_ctx, |
2dc781e0 | 51 | struct lttng_ctx_value *value) |
a6cf40a4 MJ |
52 | { |
53 | unsigned int user_ns_inum = 0; | |
54 | ||
55 | if (current_user_ns()) | |
93e5bcec | 56 | user_ns_inum = current_user_ns()->ns.inum; |
a6cf40a4 | 57 | |
2dc781e0 | 58 | value->u.s64 = user_ns_inum; |
a6cf40a4 MJ |
59 | } |
60 | ||
437d5aa5 MD |
61 | static const struct lttng_kernel_ctx_field *ctx_field = lttng_kernel_static_ctx_field( |
62 | lttng_kernel_static_event_field("user_ns", | |
63 | lttng_kernel_static_type_integer_from_type(unsigned int, __BYTE_ORDER, 10), | |
4697aac7 | 64 | false, false), |
437d5aa5 | 65 | user_ns_get_size, |
437d5aa5 MD |
66 | user_ns_record, |
67 | user_ns_get_value, | |
68 | NULL, NULL); | |
69 | ||
70 | int lttng_add_user_ns_to_ctx(struct lttng_kernel_ctx **ctx) | |
a6cf40a4 | 71 | { |
437d5aa5 | 72 | int ret; |
a6cf40a4 | 73 | |
437d5aa5 | 74 | if (lttng_kernel_find_context(*ctx, ctx_field->event_field->name)) |
a6cf40a4 | 75 | return -EEXIST; |
437d5aa5 | 76 | ret = lttng_kernel_context_append(ctx, ctx_field); |
263b6c88 | 77 | wrapper_vmalloc_sync_mappings(); |
437d5aa5 | 78 | return ret; |
a6cf40a4 MJ |
79 | } |
80 | EXPORT_SYMBOL_GPL(lttng_add_user_ns_to_ctx); | |
81 | ||
82 | #endif |