diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 05fa804d1c16..a8b624ccd4d6 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -469,10 +469,10 @@ struct tracer_switch_ops {
 	void				*private;
 	struct tracer_switch_ops	*next;
 };
-
-char *trace_find_cmdline(int pid);
 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 
+extern char *trace_find_cmdline(int pid);
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 extern unsigned long ftrace_update_tot_cnt;
 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func