2 * Copyright (C) 2004 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
12 #include <linux/module.h>
13 #include <linux/uts.h>
14 #include <linux/utsname.h>
15 #include <linux/version.h>
16 #include <linux/vserver/global.h>
19 * Clone a new ns copying an original utsname, setting refcount to 1
20 * @old_ns: namespace to clone
21 * Return NULL on error (failure to kmalloc), new ns otherwise
23 static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns)
25 struct uts_namespace *ns;
27 ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL);
29 memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
31 atomic_inc(&vs_global_uts_ns);
37 * unshare the current process' utsname namespace.
38 * called only in sys_unshare()
40 int unshare_utsname(unsigned long unshare_flags, struct uts_namespace **new_uts)
42 if (unshare_flags & CLONE_NEWUTS) {
43 if (!capable(CAP_SYS_ADMIN))
46 *new_uts = clone_uts_ns(current->nsproxy->uts_ns);
55 * Copy task tsk's utsname namespace, or clone it if flags
56 * specifies CLONE_NEWUTS. In latter case, changes to the
57 * utsname of this process won't be seen by parent, and vice
60 int copy_utsname(int flags, struct task_struct *tsk)
62 struct uts_namespace *old_ns = tsk->nsproxy->uts_ns;
63 struct uts_namespace *new_ns;
71 if (!(flags & CLONE_NEWUTS))
74 if (!capable(CAP_SYS_ADMIN)) {
79 new_ns = clone_uts_ns(old_ns);
84 tsk->nsproxy->uts_ns = new_ns;
91 void free_uts_ns(struct kref *kref)
93 struct uts_namespace *ns;
95 ns = container_of(kref, struct uts_namespace, kref);
96 atomic_dec(&vs_global_uts_ns);