mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 05:34:00 +08:00
071df104f8
Implement a CLONE_NEWUTS flag, and use it at clone and sys_unshare. [clg@fr.ibm.com: IPC unshare fix] [bunk@stusta.de: cleanup] Signed-off-by: Serge Hallyn <serue@us.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Andrey Savochkin <saw@sw.ru> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
96 lines
2.0 KiB
C
96 lines
2.0 KiB
C
/*
|
|
* Copyright (C) 2004 IBM Corporation
|
|
*
|
|
* Author: Serge Hallyn <serue@us.ibm.com>
|
|
*
|
|
* 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/version.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) {
|
|
memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
|
|
kref_init(&ns->kref);
|
|
}
|
|
return ns;
|
|
}
|
|
|
|
/*
|
|
* unshare the current process' utsname namespace.
|
|
* called only in sys_unshare()
|
|
*/
|
|
int unshare_utsname(unsigned long unshare_flags, struct uts_namespace **new_uts)
|
|
{
|
|
if (unshare_flags & CLONE_NEWUTS) {
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
*new_uts = clone_uts_ns(current->nsproxy->uts_ns);
|
|
if (!*new_uts)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
int copy_utsname(int flags, struct task_struct *tsk)
|
|
{
|
|
struct uts_namespace *old_ns = tsk->nsproxy->uts_ns;
|
|
struct uts_namespace *new_ns;
|
|
int err = 0;
|
|
|
|
if (!old_ns)
|
|
return 0;
|
|
|
|
get_uts_ns(old_ns);
|
|
|
|
if (!(flags & CLONE_NEWUTS))
|
|
return 0;
|
|
|
|
if (!capable(CAP_SYS_ADMIN)) {
|
|
err = -EPERM;
|
|
goto out;
|
|
}
|
|
|
|
new_ns = clone_uts_ns(old_ns);
|
|
if (!new_ns) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
tsk->nsproxy->uts_ns = new_ns;
|
|
|
|
out:
|
|
put_uts_ns(old_ns);
|
|
return err;
|
|
}
|
|
|
|
void free_uts_ns(struct kref *kref)
|
|
{
|
|
struct uts_namespace *ns;
|
|
|
|
ns = container_of(kref, struct uts_namespace, kref);
|
|
kfree(ns);
|
|
}
|