1 files changed, 26 insertions, 9 deletions

diff --git a/kernel/user.c b/kernel/user.c
index d8b332c3ae3a..850e0ba41c1e 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -72,6 +72,7 @@ static void uid_hash_insert(struct user_struct *up, struct hlist_head *hashent)
 static void uid_hash_remove(struct user_struct *up)
 {
         hlist_del_init(&up->uidhash_node);
+        put_user_ns(up->user_ns);
 }
 
 static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
@@ -285,14 +286,12 @@ int __init uids_sysfs_init(void)
 /* work function to remove sysfs directory for a user and free up
  * corresponding structures.
  */
-static void remove_user_sysfs_dir(struct work_struct *w)
+static void cleanup_user_struct(struct work_struct *w)
 {
         struct user_struct *up = container_of(w, struct user_struct, work);
         unsigned long flags;
         int remove_user = 0;
 
-        if (up->user_ns != &init_user_ns)
-                return;
         /* Make uid_hash_remove() + sysfs_remove_file() + kobject_del()
          * atomic.
          */
@@ -311,9 +310,11 @@ static void remove_user_sysfs_dir(struct work_struct *w)
         if (!remove_user)
                 goto done;
 
-        kobject_uevent(&up->kobj, KOBJ_REMOVE);
-        kobject_del(&up->kobj);
-        kobject_put(&up->kobj);
+        if (up->user_ns == &init_user_ns) {
+                kobject_uevent(&up->kobj, KOBJ_REMOVE);
+                kobject_del(&up->kobj);
+                kobject_put(&up->kobj);
+        }
 
         sched_destroy_user(up);
         key_put(up->uid_keyring);
@@ -334,8 +335,7 @@ static void free_user(struct user_struct *up, unsigned long flags)
         atomic_inc(&up->__count);
         spin_unlock_irqrestore(&uidhash_lock, flags);
 
-        put_user_ns(up->user_ns);
-        INIT_WORK(&up->work, remove_user_sysfs_dir);
+        INIT_WORK(&up->work, cleanup_user_struct);
         schedule_work(&up->work);
 }
 
@@ -357,12 +357,29 @@ static void free_user(struct user_struct *up, unsigned long flags)
         sched_destroy_user(up);
         key_put(up->uid_keyring);
         key_put(up->session_keyring);
-        put_user_ns(up->user_ns);
         kmem_cache_free(uid_cachep, up);
 }
 
 #endif
 
+#if defined(CONFIG_RT_GROUP_SCHED) && defined(CONFIG_USER_SCHED)
+/*
+ * We need to check if a setuid can take place. This function should be called
+ * before successfully completing the setuid.
+ */
+int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
+{
+
+        return sched_rt_can_attach(up->tg, tsk);
+
+}
+#else
+int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
+{
+        return 1;
+}
+#endif
+
 /*
  * Locate the user_struct for the passed UID.  If found, take a ref on it.  The
  * caller must undo that ref with free_uid().