utsname.c (4865ecf1315b450ab3317a745a6678c04d311e40) utsname.c (071df104f808b8195c40643dcb4d060681742e29)
1/*
2 * Copyright (C) 2004 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/uts.h>
14#include <linux/utsname.h>
15#include <linux/version.h>
16
17/*
1/*
2 * Copyright (C) 2004 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/uts.h>
14#include <linux/utsname.h>
15#include <linux/version.h>
16
17/*
18 * Clone a new ns copying an original utsname, setting refcount to 1
19 * @old_ns: namespace to clone
20 * Return NULL on error (failure to kmalloc), new ns otherwise
21 */
22static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns)
23{
24 struct uts_namespace *ns;
25
26 ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL);
27 if (ns) {
28 memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
29 kref_init(&ns->kref);
30 }
31 return ns;
32}
33
34/*
35 * unshare the current process' utsname namespace.
36 * called only in sys_unshare()
37 */
38int unshare_utsname(unsigned long unshare_flags, struct uts_namespace **new_uts)
39{
40 if (unshare_flags & CLONE_NEWUTS) {
41 if (!capable(CAP_SYS_ADMIN))
42 return -EPERM;
43
44 *new_uts = clone_uts_ns(current->nsproxy->uts_ns);
45 if (!*new_uts)
46 return -ENOMEM;
47 }
48
49 return 0;
50}
51
52/*
18 * Copy task tsk's utsname namespace, or clone it if flags
19 * specifies CLONE_NEWUTS. In latter case, changes to the
20 * utsname of this process won't be seen by parent, and vice
21 * versa.
22 */
23int copy_utsname(int flags, struct task_struct *tsk)
24{
25 struct uts_namespace *old_ns = tsk->nsproxy->uts_ns;
53 * Copy task tsk's utsname namespace, or clone it if flags
54 * specifies CLONE_NEWUTS. In latter case, changes to the
55 * utsname of this process won't be seen by parent, and vice
56 * versa.
57 */
58int copy_utsname(int flags, struct task_struct *tsk)
59{
60 struct uts_namespace *old_ns = tsk->nsproxy->uts_ns;
61 struct uts_namespace *new_ns;
26 int err = 0;
27
28 if (!old_ns)
29 return 0;
30
31 get_uts_ns(old_ns);
32
62 int err = 0;
63
64 if (!old_ns)
65 return 0;
66
67 get_uts_ns(old_ns);
68
69 if (!(flags & CLONE_NEWUTS))
70 return 0;
71
72 if (!capable(CAP_SYS_ADMIN)) {
73 err = -EPERM;
74 goto out;
75 }
76
77 new_ns = clone_uts_ns(old_ns);
78 if (!new_ns) {
79 err = -ENOMEM;
80 goto out;
81 }
82 tsk->nsproxy->uts_ns = new_ns;
83
84out:
85 put_uts_ns(old_ns);
33 return err;
34}
35
36void free_uts_ns(struct kref *kref)
37{
38 struct uts_namespace *ns;
39
40 ns = container_of(kref, struct uts_namespace, kref);
41 kfree(ns);
42}
86 return err;
87}
88
89void free_uts_ns(struct kref *kref)
90{
91 struct uts_namespace *ns;
92
93 ns = container_of(kref, struct uts_namespace, kref);
94 kfree(ns);
95}