1 files changed, 4 insertions, 2 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f1ed080406c3..ebff62ef40be 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2643,8 +2643,10 @@ static int start_graph_tracing(void)
                 return -ENOMEM;
 
         /* The cpu_boot init_task->ret_stack will never be freed */
-        for_each_online_cpu(cpu)
-                ftrace_graph_init_task(idle_task(cpu));
+        for_each_online_cpu(cpu) {
+                if (!idle_task(cpu)->ret_stack)
+                        ftrace_graph_init_task(idle_task(cpu));
+        }
 
         do {
                 ret = alloc_retstack_tasklist(ret_stack_list);