timer: Fix lock inversion between hrtimer_bases.lock and scheduler locks

[platform/adaptation/renesas_rcar/renesas_kernel.git] / kernel / pid_namespace.c

diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 4208655..db95d8e 100644 (file)
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -132,6 +132,12 @@ out:
        return ERR_PTR(err);
 }
 
+static void delayed_free_pidns(struct rcu_head *p)
+{
+       kmem_cache_free(pid_ns_cachep,
+                       container_of(p, struct pid_namespace, rcu));
+}
+
 static void destroy_pid_namespace(struct pid_namespace *ns)
 {
        int i;
@@ -140,7 +146,7 @@ static void destroy_pid_namespace(struct pid_namespace *ns)
        for (i = 0; i < PIDMAP_ENTRIES; i++)
                kfree(ns->pidmap[i].page);
        put_user_ns(ns->user_ns);
-       kmem_cache_free(pid_ns_cachep, ns);
+       call_rcu(&ns->rcu, delayed_free_pidns);
 }
 
 struct pid_namespace *copy_pid_ns(unsigned long flags,
@@ -312,7 +318,9 @@ static void *pidns_get(struct task_struct *task)
        struct pid_namespace *ns;
 
        rcu_read_lock();
-       ns = get_pid_ns(task_active_pid_ns(task));
+       ns = task_active_pid_ns(task);
+       if (ns)
+               get_pid_ns(ns);
        rcu_read_unlock();
 
        return ns;