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![Paul Mundt](/assets/img/avatar_default.png)
Slab destructors were no longer supported after Christoph's
c59def9f22
change. They've been
BUGs for both slab and slub, and slob never supported them
either.
This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
200 lines
4.4 KiB
C
200 lines
4.4 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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static struct kmem_cache *nsproxy_cachep;
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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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*/
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static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig)
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{
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struct nsproxy *ns;
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ns = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
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if (ns) {
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memcpy(ns, orig, sizeof(struct nsproxy));
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atomic_set(&ns->count, 1);
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}
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return ns;
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}
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/*
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* Create new nsproxy and all of its the associated namespaces.
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* Return the newly created nsproxy. Do not attach this to the task,
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* leave it to the caller to do proper locking and attach it to task.
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*/
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static struct nsproxy *create_new_namespaces(unsigned long flags,
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struct task_struct *tsk, struct fs_struct *new_fs)
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{
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struct nsproxy *new_nsp;
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int err;
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new_nsp = clone_nsproxy(tsk->nsproxy);
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if (!new_nsp)
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return ERR_PTR(-ENOMEM);
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new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
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if (IS_ERR(new_nsp->mnt_ns)) {
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err = PTR_ERR(new_nsp->mnt_ns);
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goto out_ns;
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}
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new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
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if (IS_ERR(new_nsp->uts_ns)) {
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err = PTR_ERR(new_nsp->uts_ns);
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goto out_uts;
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}
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new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
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if (IS_ERR(new_nsp->ipc_ns)) {
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err = PTR_ERR(new_nsp->ipc_ns);
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goto out_ipc;
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}
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new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);
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if (IS_ERR(new_nsp->pid_ns)) {
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err = PTR_ERR(new_nsp->pid_ns);
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goto out_pid;
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}
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new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns);
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if (IS_ERR(new_nsp->user_ns)) {
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err = PTR_ERR(new_nsp->user_ns);
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goto out_user;
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}
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return new_nsp;
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out_user:
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if (new_nsp->pid_ns)
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put_pid_ns(new_nsp->pid_ns);
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out_pid:
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if (new_nsp->ipc_ns)
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put_ipc_ns(new_nsp->ipc_ns);
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out_ipc:
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if (new_nsp->uts_ns)
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put_uts_ns(new_nsp->uts_ns);
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out_uts:
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if (new_nsp->mnt_ns)
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put_mnt_ns(new_nsp->mnt_ns);
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out_ns:
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kmem_cache_free(nsproxy_cachep, new_nsp);
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return ERR_PTR(err);
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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(unsigned long 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 | CLONE_NEWUSER)))
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return 0;
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if (!capable(CAP_SYS_ADMIN)) {
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err = -EPERM;
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goto out;
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}
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new_ns = create_new_namespaces(flags, tsk, tsk->fs);
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if (IS_ERR(new_ns)) {
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err = PTR_ERR(new_ns);
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goto out;
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}
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tsk->nsproxy = new_ns;
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out:
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put_nsproxy(old_ns);
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return err;
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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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if (ns->user_ns)
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put_user_ns(ns->user_ns);
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kmem_cache_free(nsproxy_cachep, ns);
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}
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/*
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* Called from unshare. Unshare all the namespaces part of nsproxy.
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* On success, returns the new nsproxy.
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*/
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int unshare_nsproxy_namespaces(unsigned long unshare_flags,
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struct nsproxy **new_nsp, struct fs_struct *new_fs)
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{
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int err = 0;
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if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
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CLONE_NEWUSER)))
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return 0;
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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*new_nsp = create_new_namespaces(unshare_flags, current,
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new_fs ? new_fs : current->fs);
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if (IS_ERR(*new_nsp))
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err = PTR_ERR(*new_nsp);
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return err;
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}
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static int __init nsproxy_cache_init(void)
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{
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nsproxy_cachep = kmem_cache_create("nsproxy", sizeof(struct nsproxy),
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0, SLAB_PANIC, NULL);
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return 0;
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}
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module_init(nsproxy_cache_init);
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