v4.19.13 snapshot.
diff --git a/lib/kstrtox.h b/lib/kstrtox.h
new file mode 100644
index 0000000..3b4637b
--- /dev/null
+++ b/lib/kstrtox.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LIB_KSTRTOX_H
+#define _LIB_KSTRTOX_H
+
+#define KSTRTOX_OVERFLOW	(1U << 31)
+const char *_parse_integer_fixup_radix(const char *s, unsigned int *base);
+unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *res);
+
+#endif