diff --git a/sys/compat/linuxkpi/common/include/linux/kernel.h b/sys/compat/linuxkpi/common/include/linux/kernel.h
--- a/sys/compat/linuxkpi/common/include/linux/kernel.h
+++ b/sys/compat/linuxkpi/common/include/linux/kernel.h
@@ -393,6 +393,24 @@
 	return (0);
 }
 
+static inline int
+kstrtou8(const char *cp, unsigned int base, u8 *res)
+{
+	char *end;
+	unsigned long temp;
+
+	*res = temp = strtoul(cp, &end, base);
+
+	/* skip newline character, if any */
+	if (*end == '\n')
+		end++;
+	if (*cp == 0 || *end != 0)
+		return (-EINVAL);
+	if (temp != (u8)temp)
+		return (-ERANGE);
+	return (0);
+}
+
 static inline int
 kstrtou16(const char *cp, unsigned int base, u16 *res)
 {
@@ -484,6 +502,21 @@
 	return (kstrtobool(buf, res));
 }
 
+static inline int
+kstrtou8_from_user(const char __user *s, size_t count, unsigned int base,
+    u8 *p)
+{
+	char buf[8] = {};
+
+	if (count > (sizeof(buf) - 1))
+		count = (sizeof(buf) - 1);
+
+	if (copy_from_user(buf, s, count))
+		return (-EFAULT);
+
+	return (kstrtou8(buf, base, p));
+}
+
 #define min(x, y)	((x) < (y) ? (x) : (y))
 #define max(x, y)	((x) > (y) ? (x) : (y))