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b7cdc182 | 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
dc923e75 MJ |
2 | * |
3 | * lttng-context-vsuid.c | |
4 | * | |
5 | * LTTng namespaced saved set-user-ID 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/sched.h> | |
14 | #include <lttng-events.h> | |
15 | #include <lttng-tracer.h> | |
16 | #include <wrapper/ringbuffer/frontend_types.h> | |
dc923e75 MJ |
17 | #include <wrapper/user_namespace.h> |
18 | ||
19 | static | |
20 | size_t vsuid_get_size(size_t offset) | |
21 | { | |
22 | size_t size = 0; | |
23 | ||
24 | size += lib_ring_buffer_align(offset, lttng_alignof(uid_t)); | |
25 | size += sizeof(uid_t); | |
26 | return size; | |
27 | } | |
28 | ||
29 | static | |
30 | void vsuid_record(struct lttng_ctx_field *field, | |
31 | struct lib_ring_buffer_ctx *ctx, | |
32 | struct lttng_channel *chan) | |
33 | { | |
34 | uid_t vsuid; | |
35 | ||
36 | vsuid = lttng_current_vsuid(); | |
37 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(vsuid)); | |
38 | chan->ops->event_write(ctx, &vsuid, sizeof(vsuid)); | |
39 | } | |
40 | ||
41 | static | |
42 | void vsuid_get_value(struct lttng_ctx_field *field, | |
43 | struct lttng_probe_ctx *lttng_probe_ctx, | |
44 | union lttng_ctx_value *value) | |
45 | { | |
46 | value->s64 = lttng_current_vsuid(); | |
47 | } | |
48 | ||
49 | int lttng_add_vsuid_to_ctx(struct lttng_ctx **ctx) | |
50 | { | |
51 | struct lttng_ctx_field *field; | |
52 | ||
53 | field = lttng_append_context(ctx); | |
54 | if (!field) | |
55 | return -ENOMEM; | |
56 | if (lttng_find_context(*ctx, "vsuid")) { | |
57 | lttng_remove_context_field(ctx, field); | |
58 | return -EEXIST; | |
59 | } | |
60 | field->event_field.name = "vsuid"; | |
61 | field->event_field.type.atype = atype_integer; | |
ceabb767 MD |
62 | field->event_field.type.u.integer.size = sizeof(uid_t) * CHAR_BIT; |
63 | field->event_field.type.u.integer.alignment = lttng_alignof(uid_t) * CHAR_BIT; | |
64 | field->event_field.type.u.integer.signedness = lttng_is_signed_type(uid_t); | |
65 | field->event_field.type.u.integer.reverse_byte_order = 0; | |
66 | field->event_field.type.u.integer.base = 10; | |
67 | field->event_field.type.u.integer.encoding = lttng_encode_none; | |
dc923e75 MJ |
68 | field->get_size = vsuid_get_size; |
69 | field->record = vsuid_record; | |
70 | field->get_value = vsuid_get_value; | |
71 | lttng_context_update(*ctx); | |
dc923e75 MJ |
72 | return 0; |
73 | } | |
74 | EXPORT_SYMBOL_GPL(lttng_add_vsuid_to_ctx); |