Merge branch 'for-linus' of git://git.kernel.dk/data/git/linux-2.6-block

[sfrench/cifs-2.6.git] / kernel / nsproxy.c

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 1bc4b55241a8c720e16a5ed12efd108875229dcc..10f0bbba382bed8c37d498cd55cf5871eb9b8bd4 100644 (file)
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -21,6 +21,8 @@
 #include <linux/utsname.h>
 #include <linux/pid_namespace.h>
 
+static struct kmem_cache *nsproxy_cachep;
+
 struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 static inline void get_nsproxy(struct nsproxy *ns)
@@ -43,9 +45,11 @@ static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig)
 {
        struct nsproxy *ns;
 
-       ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL);
-       if (ns)
+       ns = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
+       if (ns) {
+               memcpy(ns, orig, sizeof(struct nsproxy));
                atomic_set(&ns->count, 1);
+       }
        return ns;
 }
 
@@ -54,33 +58,51 @@ static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig)
  * Return the newly created nsproxy.  Do not attach this to the task,
  * leave it to the caller to do proper locking and attach it to task.
  */
-static struct nsproxy *create_new_namespaces(int flags, struct task_struct *tsk,
-                       struct fs_struct *new_fs)
+static struct nsproxy *create_new_namespaces(unsigned long flags,
+                       struct task_struct *tsk, struct fs_struct *new_fs)
 {
        struct nsproxy *new_nsp;
+       int err;
 
        new_nsp = clone_nsproxy(tsk->nsproxy);
        if (!new_nsp)
                return ERR_PTR(-ENOMEM);
 
        new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
-       if (IS_ERR(new_nsp->mnt_ns))
+       if (IS_ERR(new_nsp->mnt_ns)) {
+               err = PTR_ERR(new_nsp->mnt_ns);
                goto out_ns;
+       }
 
        new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
-       if (IS_ERR(new_nsp->uts_ns))
+       if (IS_ERR(new_nsp->uts_ns)) {
+               err = PTR_ERR(new_nsp->uts_ns);
                goto out_uts;
+       }
 
        new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
-       if (IS_ERR(new_nsp->ipc_ns))
+       if (IS_ERR(new_nsp->ipc_ns)) {
+               err = PTR_ERR(new_nsp->ipc_ns);
                goto out_ipc;
+       }
 
        new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);
-       if (IS_ERR(new_nsp->pid_ns))
+       if (IS_ERR(new_nsp->pid_ns)) {
+               err = PTR_ERR(new_nsp->pid_ns);
                goto out_pid;
+       }
+
+       new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns);
+       if (IS_ERR(new_nsp->user_ns)) {
+               err = PTR_ERR(new_nsp->user_ns);
+               goto out_user;
+       }
 
        return new_nsp;
 
+out_user:
+       if (new_nsp->pid_ns)
+               put_pid_ns(new_nsp->pid_ns);
 out_pid:
        if (new_nsp->ipc_ns)
                put_ipc_ns(new_nsp->ipc_ns);
@@ -91,15 +113,15 @@ out_uts:
        if (new_nsp->mnt_ns)
                put_mnt_ns(new_nsp->mnt_ns);
 out_ns:
-       kfree(new_nsp);
-       return ERR_PTR(-ENOMEM);
+       kmem_cache_free(nsproxy_cachep, new_nsp);
+       return ERR_PTR(err);
 }
 
 /*
  * called from clone.  This now handles copy for nsproxy and all
  * namespaces therein.
  */
-int copy_namespaces(int flags, struct task_struct *tsk)
+int copy_namespaces(unsigned long flags, struct task_struct *tsk)
 {
        struct nsproxy *old_ns = tsk->nsproxy;
        struct nsproxy *new_ns;
@@ -110,7 +132,7 @@ int copy_namespaces(int flags, struct task_struct *tsk)
 
        get_nsproxy(old_ns);
 
-       if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
+       if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWUSER)))
                return 0;
 
        if (!capable(CAP_SYS_ADMIN)) {
@@ -140,43 +162,39 @@ void free_nsproxy(struct nsproxy *ns)
                put_ipc_ns(ns->ipc_ns);
        if (ns->pid_ns)
                put_pid_ns(ns->pid_ns);
-       kfree(ns);
+       if (ns->user_ns)
+               put_user_ns(ns->user_ns);
+       kmem_cache_free(nsproxy_cachep, ns);
 }
 
 /*
  * Called from unshare. Unshare all the namespaces part of nsproxy.
- * On sucess, returns the new nsproxy and a reference to old nsproxy
- * to make sure it stays around.
+ * On success, returns the new nsproxy.
  */
 int unshare_nsproxy_namespaces(unsigned long unshare_flags,
                struct nsproxy **new_nsp, struct fs_struct *new_fs)
 {
-       struct nsproxy *old_ns = current->nsproxy;
        int err = 0;
 
-       if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
+       if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
+                              CLONE_NEWUSER)))
                return 0;
 
-#ifndef CONFIG_IPC_NS
-       if (unshare_flags & CLONE_NEWIPC)
-               return -EINVAL;
-#endif
-
-#ifndef CONFIG_UTS_NS
-       if (unshare_flags & CLONE_NEWUTS)
-               return -EINVAL;
-#endif
-
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
 
-       get_nsproxy(old_ns);
-
        *new_nsp = create_new_namespaces(unshare_flags, current,
                                new_fs ? new_fs : current->fs);
-       if (IS_ERR(*new_nsp)) {
+       if (IS_ERR(*new_nsp))
                err = PTR_ERR(*new_nsp);
-               put_nsproxy(old_ns);
-       }
        return err;
 }
+
+static int __init nsproxy_cache_init(void)
+{
+       nsproxy_cachep = kmem_cache_create("nsproxy", sizeof(struct nsproxy),
+                                          0, SLAB_PANIC, NULL, NULL);
+       return 0;
+}
+
+module_init(nsproxy_cache_init);