diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
index bd90e1b06088a74d890b011f6bec7b61d7cf2383..8faa7ce588144afe9fb9a3b8c84d67eb1388024d 100644
--- a/kernel/trace/trace_kdb.c
+++ b/kernel/trace/trace_kdb.c
@@ -20,10 +20,12 @@ static void ftrace_dump_buf(int skip_lines, long cpu_file)
 {
 	/* use static because iter can be a bit big for the stack */
 	static struct trace_iterator iter;
+	static struct ring_buffer_iter *buffer_iter[CONFIG_NR_CPUS];
 	unsigned int old_userobj;
 	int cnt = 0, cpu;
 
 	trace_init_global_iter(&iter);
+	iter.buffer_iter = buffer_iter;
 
 	for_each_tracing_cpu(cpu) {
 		atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
@@ -86,9 +88,12 @@ static void ftrace_dump_buf(int skip_lines, long cpu_file)
 		atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
 	}
 
-	for_each_tracing_cpu(cpu)
-		if (iter.buffer_iter[cpu])
+	for_each_tracing_cpu(cpu) {
+		if (iter.buffer_iter[cpu]) {
 			ring_buffer_read_finish(iter.buffer_iter[cpu]);
+			iter.buffer_iter[cpu] = NULL;
+		}
+	}
 }
 
 /*