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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - kernel/nsproxy.c
2 * Copyright (C) 2006 IBM Corporation
4 * Author: Serge Hallyn <serue@us.ibm.com>
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
11 * Jun 2006 - namespaces support
13 * Pavel Emelianov <xemul@openvz.org>
16 #include <linux/module.h>
17 #include <linux/version.h>
18 #include <linux/nsproxy.h>
19 #include <linux/init_task.h>
20 #include <linux/namespace.h>
21 #include <linux/utsname.h>
23 struct nsproxy init_nsproxy
= INIT_NSPROXY(init_nsproxy
);
25 static inline void get_nsproxy(struct nsproxy
*ns
)
27 atomic_inc(&ns
->count
);
30 void get_task_namespaces(struct task_struct
*tsk
)
32 struct nsproxy
*ns
= tsk
->nsproxy
;
39 * creates a copy of "orig" with refcount 1.
40 * This does not grab references to the contained namespaces,
41 * so that needs to be done by dup_namespaces.
43 static inline struct nsproxy
*clone_namespaces(struct nsproxy
*orig
)
47 ns
= kmemdup(orig
, sizeof(struct nsproxy
), GFP_KERNEL
);
49 atomic_set(&ns
->count
, 1);
54 * copies the nsproxy, setting refcount to 1, and grabbing a
55 * reference to all contained namespaces. Called from
58 struct nsproxy
*dup_namespaces(struct nsproxy
*orig
)
60 struct nsproxy
*ns
= clone_namespaces(orig
);
64 get_namespace(ns
->namespace);
66 get_uts_ns(ns
->uts_ns
);
68 get_ipc_ns(ns
->ipc_ns
);
75 * called from clone. This now handles copy for nsproxy and all
78 int copy_namespaces(int flags
, struct task_struct
*tsk
)
80 struct nsproxy
*old_ns
= tsk
->nsproxy
;
81 struct nsproxy
*new_ns
;
89 if (!(flags
& (CLONE_NEWNS
| CLONE_NEWUTS
| CLONE_NEWIPC
)))
92 new_ns
= clone_namespaces(old_ns
);
98 tsk
->nsproxy
= new_ns
;
100 err
= copy_namespace(flags
, tsk
);
104 err
= copy_utsname(flags
, tsk
);
108 err
= copy_ipcs(flags
, tsk
);
118 put_uts_ns(new_ns
->uts_ns
);
120 if (new_ns
->namespace)
121 put_namespace(new_ns
->namespace);
123 tsk
->nsproxy
= old_ns
;
128 void free_nsproxy(struct nsproxy
*ns
)
131 put_namespace(ns
->namespace);
133 put_uts_ns(ns
->uts_ns
);
135 put_ipc_ns(ns
->ipc_ns
);