protect writing to per_cpu_call_rcu_data[*]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/urcu-call-rcu-impl.h b/urcu-call-rcu-impl.h
index 6e80fa98c8aea9ebd7a7a835ea8fa3c52546228e..c822646e03834bbf26224feae2a71bcdfb5bf8e1 100644 (file)
--- a/urcu-call-rcu-impl.h
+++ b/urcu-call-rcu-impl.h
@@ -396,12 +396,13 @@ int set_cpu_call_rcu_data(int cpu, struct call_rcu_data *crdp)
                errno = EINVAL;
                return -EINVAL;
        }
-       call_rcu_unlock(&call_rcu_mutex);
        if (per_cpu_call_rcu_data == NULL) {
+               call_rcu_unlock(&call_rcu_mutex);
                errno = ENOMEM;
                return -ENOMEM;
        }
        per_cpu_call_rcu_data[cpu] = crdp;
+       call_rcu_unlock(&call_rcu_mutex);
        return 0;
 }