1 files changed, 46 insertions, 16 deletions

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 049e7c0ac566..79f871bc0ef4 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -26,19 +26,6 @@ static struct kmem_cache *nsproxy_cachep;
 
 struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
-static inline void get_nsproxy(struct nsproxy *ns)
-{
-        atomic_inc(&ns->count);
-}
-
-void get_task_namespaces(struct task_struct *tsk)
-{
-        struct nsproxy *ns = tsk->nsproxy;
-        if (ns) {
-                get_nsproxy(ns);
-        }
-}
-
 /*
  * creates a copy of "orig" with refcount 1.
  */
@@ -87,7 +74,7 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
                 goto out_ipc;
         }
 
-        new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);
+        new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk));
         if (IS_ERR(new_nsp->pid_ns)) {
                 err = PTR_ERR(new_nsp->pid_ns);
                 goto out_pid;
@@ -142,7 +129,8 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
 
         get_nsproxy(old_ns);
 
-        if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWUSER | CLONE_NEWNET)))
+        if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
+                                CLONE_NEWUSER | CLONE_NEWPID | CLONE_NEWNET)))
                 return 0;
 
         if (!capable(CAP_SYS_ADMIN)) {
@@ -156,7 +144,14 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
                 goto out;
         }
 
+        err = ns_cgroup_clone(tsk);
+        if (err) {
+                put_nsproxy(new_ns);
+                goto out;
+        }
+
         tsk->nsproxy = new_ns;
+
 out:
         put_nsproxy(old_ns);
         return err;
@@ -196,11 +191,46 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags,
 
         *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);
+                goto out;
+        }
+
+        err = ns_cgroup_clone(current);
+        if (err)
+                put_nsproxy(*new_nsp);
+
+out:
         return err;
 }
 
+void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
+{
+        struct nsproxy *ns;
+
+        might_sleep();
+
+        ns = p->nsproxy;
+
+        rcu_assign_pointer(p->nsproxy, new);
+
+        if (ns && atomic_dec_and_test(&ns->count)) {
+                /*
+                 * wait for others to get what they want from this nsproxy.
+                 *
+                 * cannot release this nsproxy via the call_rcu() since
+                 * put_mnt_ns() will want to sleep
+                 */
+                synchronize_rcu();
+                free_nsproxy(ns);
+        }
+}
+
+void exit_task_namespaces(struct task_struct *p)
+{
+        switch_task_namespaces(p, NULL);
+}
+
 static int __init nsproxy_cache_init(void)
 {
         nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);