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5f8442edfb
This reverts commit 373beb35cd.
No one is using this identifier yet. The purpose of this identifier is to
export nsproxy to user space which is wrong. nsproxy is an internal
implementation optimization, which should keep our fork times from getting
slower as we increase the number of global namespaces you don't have to
share.
Adding a global identifier like this is inappropriate because it makes
namespaces inherently non-recursive, greatly limiting what we can do with
them in the future.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
150 lines
2.9 KiB
C
150 lines
2.9 KiB
C
/*
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* Copyright (C) 2006 IBM Corporation
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*
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* Author: Serge Hallyn <serue@us.ibm.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*
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* Jun 2006 - namespaces support
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* OpenVZ, SWsoft Inc.
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* Pavel Emelianov <xemul@openvz.org>
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*/
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#include <linux/module.h>
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#include <linux/version.h>
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#include <linux/nsproxy.h>
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#include <linux/init_task.h>
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#include <linux/mnt_namespace.h>
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#include <linux/utsname.h>
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#include <linux/pid_namespace.h>
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struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
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static inline void get_nsproxy(struct nsproxy *ns)
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{
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atomic_inc(&ns->count);
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}
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void get_task_namespaces(struct task_struct *tsk)
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{
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struct nsproxy *ns = tsk->nsproxy;
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if (ns) {
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get_nsproxy(ns);
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}
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}
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/*
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* creates a copy of "orig" with refcount 1.
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* This does not grab references to the contained namespaces,
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* so that needs to be done by dup_namespaces.
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*/
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static inline struct nsproxy *clone_namespaces(struct nsproxy *orig)
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{
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struct nsproxy *ns;
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ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL);
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if (ns)
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atomic_set(&ns->count, 1);
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return ns;
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}
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/*
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* copies the nsproxy, setting refcount to 1, and grabbing a
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* reference to all contained namespaces. Called from
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* sys_unshare()
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*/
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struct nsproxy *dup_namespaces(struct nsproxy *orig)
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{
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struct nsproxy *ns = clone_namespaces(orig);
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if (ns) {
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if (ns->mnt_ns)
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get_mnt_ns(ns->mnt_ns);
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if (ns->uts_ns)
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get_uts_ns(ns->uts_ns);
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if (ns->ipc_ns)
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get_ipc_ns(ns->ipc_ns);
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if (ns->pid_ns)
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get_pid_ns(ns->pid_ns);
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}
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return ns;
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}
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/*
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* called from clone. This now handles copy for nsproxy and all
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* namespaces therein.
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*/
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int copy_namespaces(int flags, struct task_struct *tsk)
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{
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struct nsproxy *old_ns = tsk->nsproxy;
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struct nsproxy *new_ns;
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int err = 0;
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if (!old_ns)
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return 0;
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get_nsproxy(old_ns);
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if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
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return 0;
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new_ns = clone_namespaces(old_ns);
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if (!new_ns) {
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err = -ENOMEM;
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goto out;
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}
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tsk->nsproxy = new_ns;
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err = copy_mnt_ns(flags, tsk);
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if (err)
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goto out_ns;
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err = copy_utsname(flags, tsk);
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if (err)
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goto out_uts;
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err = copy_ipcs(flags, tsk);
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if (err)
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goto out_ipc;
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err = copy_pid_ns(flags, tsk);
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if (err)
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goto out_pid;
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out:
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put_nsproxy(old_ns);
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return err;
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out_pid:
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if (new_ns->ipc_ns)
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put_ipc_ns(new_ns->ipc_ns);
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out_ipc:
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if (new_ns->uts_ns)
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put_uts_ns(new_ns->uts_ns);
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out_uts:
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if (new_ns->mnt_ns)
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put_mnt_ns(new_ns->mnt_ns);
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out_ns:
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tsk->nsproxy = old_ns;
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kfree(new_ns);
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goto out;
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}
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void free_nsproxy(struct nsproxy *ns)
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{
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if (ns->mnt_ns)
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put_mnt_ns(ns->mnt_ns);
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if (ns->uts_ns)
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put_uts_ns(ns->uts_ns);
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if (ns->ipc_ns)
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put_ipc_ns(ns->ipc_ns);
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if (ns->pid_ns)
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put_pid_ns(ns->pid_ns);
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kfree(ns);
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}
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