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 *  Copyright (C) 2004 IBM Corporation
 *  Author: Serge Hallyn <>
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as
 *  published by the Free Software Foundation, version 2 of the
 *  License.

#include <linux/module.h>
#include <linux/uts.h>
#include <linux/utsname.h>
#include <linux/err.h>
#include <linux/slab.h>

 * Clone a new ns copying an original utsname, setting refcount to 1
 * @old_ns: namespace to clone
 * Return NULL on error (failure to kmalloc), new ns otherwise
static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns)
	struct uts_namespace *ns;

	ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL);
	if (!ns)
		return ERR_PTR(-ENOMEM);

	memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
	return ns;

 * Copy task tsk's utsname namespace, or clone it if flags
 * specifies CLONE_NEWUTS.  In latter case, changes to the
 * utsname of this process won't be seen by parent, and vice
 * versa.
struct uts_namespace *copy_utsname(unsigned long flags, struct uts_namespace *old_ns)
	struct uts_namespace *new_ns;


	if (!(flags & CLONE_NEWUTS))
		return old_ns;

	new_ns = clone_uts_ns(old_ns);

	return new_ns;

void free_uts_ns(struct kref *kref)
	struct uts_namespace *ns;

	ns = container_of(kref, struct uts_namespace, kref);