diff --git a/sys/compat/linuxkpi/common/include/linux/moduleparam.h b/sys/compat/linuxkpi/common/include/linux/moduleparam.h
--- a/sys/compat/linuxkpi/common/include/linux/moduleparam.h
+++ b/sys/compat/linuxkpi/common/include/linux/moduleparam.h
@@ -102,6 +102,12 @@
 	LINUXKPI_PARAM_NAME(name), LINUXKPI_PARAM_PERM(perm), &(var), 0, \
 	LINUXKPI_PARAM_DESC(name)))
 
+#define	LINUXKPI_PARAM_charp(name, var, perm)				\
+	extern const char LINUXKPI_PARAM_DESC(name)[];			\
+	LINUXKPI_PARAM_PASS(SYSCTL_STRING(LINUXKPI_PARAM_PARENT, OID_AUTO, \
+	LINUXKPI_PARAM_NAME(name), LINUXKPI_PARAM_PERM(perm), &(var), 0, \
+	LINUXKPI_PARAM_DESC(name)))
+
 #define	module_param_string(name, str, len, perm)			\
 	extern const char LINUXKPI_PARAM_DESC(name)[];			\
 	LINUXKPI_PARAM_PASS(SYSCTL_STRING(LINUXKPI_PARAM_PARENT, OID_AUTO, \