diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 2d35bbf687d0..598d7072602f 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -93,9 +93,8 @@ struct bug_entry {
 extern __printf(4, 5)
 void warn_slowpath_fmt(const char *file, const int line, unsigned taint,
 		       const char *fmt, ...);
-extern void warn_slowpath_null(const char *file, const int line);
 #define WANT_WARN_ON_SLOWPATH
-#define __WARN()		warn_slowpath_null(__FILE__, __LINE__)
+#define __WARN()		__WARN_printf(TAINT_WARN, NULL)
 #define __WARN_printf(taint, arg...)					\
 	warn_slowpath_fmt(__FILE__, __LINE__, taint, arg)
 #else
diff --git a/kernel/panic.c b/kernel/panic.c
index 1d89f5423426..79c153951b59 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -605,19 +605,19 @@ void warn_slowpath_fmt(const char *file, int line, unsigned taint,
 {
 	struct warn_args args;
 
+	if (!fmt) {
+		pr_warn(CUT_HERE);
+		__warn(file, line, __builtin_return_address(0), taint,
+		       NULL, NULL);
+		return;
+	}
+
 	args.fmt = fmt;
 	va_start(args.args, fmt);
 	__warn(file, line, __builtin_return_address(0), taint, NULL, &args);
 	va_end(args.args);
 }
 EXPORT_SYMBOL(warn_slowpath_fmt);
-
-void warn_slowpath_null(const char *file, int line)
-{
-	pr_warn(CUT_HERE);
-	__warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, NULL);
-}
-EXPORT_SYMBOL(warn_slowpath_null);
 #else
 void __warn_printk(const char *fmt, ...)
 {