Commit | Line | Data |
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ab516013 SH |
1 | /* |
2 | * Copyright (C) 2006 IBM Corporation | |
3 | * | |
4 | * Author: Serge Hallyn <serue@us.ibm.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License as | |
8 | * published by the Free Software Foundation, version 2 of the | |
9 | * License. | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/version.h> | |
14 | #include <linux/nsproxy.h> | |
0437eb59 SH |
15 | #include <linux/init_task.h> |
16 | ||
17 | struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy); | |
ab516013 SH |
18 | |
19 | static inline void get_nsproxy(struct nsproxy *ns) | |
20 | { | |
21 | atomic_inc(&ns->count); | |
22 | } | |
23 | ||
24 | void get_task_namespaces(struct task_struct *tsk) | |
25 | { | |
26 | struct nsproxy *ns = tsk->nsproxy; | |
27 | if (ns) { | |
28 | get_nsproxy(ns); | |
29 | } | |
30 | } | |
31 | ||
32 | /* | |
33 | * creates a copy of "orig" with refcount 1. | |
34 | * This does not grab references to the contained namespaces, | |
35 | * so that needs to be done by dup_namespaces. | |
36 | */ | |
37 | static inline struct nsproxy *clone_namespaces(struct nsproxy *orig) | |
38 | { | |
39 | struct nsproxy *ns; | |
40 | ||
41 | ns = kmalloc(sizeof(struct nsproxy), GFP_KERNEL); | |
42 | if (ns) { | |
43 | memcpy(ns, orig, sizeof(struct nsproxy)); | |
44 | atomic_set(&ns->count, 1); | |
45 | } | |
46 | return ns; | |
47 | } | |
48 | ||
49 | /* | |
50 | * copies the nsproxy, setting refcount to 1, and grabbing a | |
51 | * reference to all contained namespaces. Called from | |
52 | * sys_unshare() | |
53 | */ | |
54 | struct nsproxy *dup_namespaces(struct nsproxy *orig) | |
55 | { | |
56 | struct nsproxy *ns = clone_namespaces(orig); | |
57 | ||
58 | return ns; | |
59 | } | |
60 | ||
61 | /* | |
62 | * called from clone. This now handles copy for nsproxy and all | |
63 | * namespaces therein. | |
64 | */ | |
65 | int copy_namespaces(int flags, struct task_struct *tsk) | |
66 | { | |
67 | struct nsproxy *old_ns = tsk->nsproxy; | |
68 | ||
69 | if (!old_ns) | |
70 | return 0; | |
71 | ||
72 | get_nsproxy(old_ns); | |
73 | ||
74 | return 0; | |
75 | } | |
76 | ||
77 | void free_nsproxy(struct nsproxy *ns) | |
78 | { | |
79 | kfree(ns); | |
80 | } |