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/err.h>
16 #include <linux/slab.h>
17 #include <linux/user_namespace.h>
18 #include <linux/proc_fs.h>
20 static struct uts_namespace *create_uts_ns(void)
22 struct uts_namespace *uts_ns;
24 uts_ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL);
26 kref_init(&uts_ns->kref);
31 * Clone a new ns copying an original utsname, setting refcount to 1
32 * @old_ns: namespace to clone
33 * Return NULL on error (failure to kmalloc), new ns otherwise
35 static struct uts_namespace *clone_uts_ns(struct task_struct *tsk,
36 struct uts_namespace *old_ns)
38 struct uts_namespace *ns;
42 return ERR_PTR(-ENOMEM);
45 memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
46 ns->user_ns = get_user_ns(task_cred_xxx(tsk, user)->user_ns);
52 * Copy task tsk's utsname namespace, or clone it if flags
53 * specifies CLONE_NEWUTS. In latter case, changes to the
54 * utsname of this process won't be seen by parent, and vice
57 struct uts_namespace *copy_utsname(unsigned long flags,
58 struct task_struct *tsk)
60 struct uts_namespace *old_ns = tsk->nsproxy->uts_ns;
61 struct uts_namespace *new_ns;
66 if (!(flags & CLONE_NEWUTS))
69 new_ns = clone_uts_ns(tsk, old_ns);
75 void free_uts_ns(struct kref *kref)
77 struct uts_namespace *ns;
79 ns = container_of(kref, struct uts_namespace, kref);
80 put_user_ns(ns->user_ns);
84 static void *utsns_get(struct task_struct *task)
86 struct uts_namespace *ns = NULL;
87 struct nsproxy *nsproxy;
90 nsproxy = task_nsproxy(task);
100 static void utsns_put(void *ns)
105 static int utsns_install(struct nsproxy *nsproxy, void *ns)
108 put_uts_ns(nsproxy->uts_ns);
109 nsproxy->uts_ns = ns;
113 const struct proc_ns_operations utsns_operations = {
115 .type = CLONE_NEWUTS,
118 .install = utsns_install,