1 files changed, 6 insertions, 0 deletions

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 10f6ad7d85f..8b592418d8b 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -65,6 +65,12 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth)
         if (!current->ret_stack)
                 return -EBUSY;
 
+        /*
+         * We must make sure the ret_stack is tested before we read
+         * anything else.
+         */
+        smp_rmb();
+
         /* The return trace stack is full */
         if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
                 atomic_inc(&current->trace_overrun);