+/* Linux 2.5.something and 2.6 pass direct pointers to arguments of
+ ioctl() calls. With 2.4, you have to do tedious copy_from_user()
+ and copy_to_user() calls. With these macros we circumvent this,
+ and let me maintain only one source file. The functionality is
+ exactly the same otherwise.
+ */
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0)
+
+/* define local variable for arg */
+#define ARG_DEF(ARG_type, ARG_name)\
+ ARG_type *ARG_name = arg;
+/* copy arg to local variable */
+#define ARG_IN(ARG_name) /* nothing */
+/* argument itself (referenced) */
+#define ARGR(ARG_name) (*ARG_name)
+/* argument address */
+#define ARGA(ARG_name) ARG_name
+/* copy local variable to arg */
+#define ARG_OUT(ARG_name) /* nothing */
+
+#else
+
+#define ARG_DEF(ARG_type, ARG_name)\
+ ARG_type ARG_name;
+#define ARG_IN(ARG_name)\
+ if (copy_from_user(&ARG_name, arg, sizeof(ARG_name))) {\
+ ret = -EFAULT;\
+ break;\
+ }
+#define ARGR(ARG_name) ARG_name
+#define ARGA(ARG_name) &ARG_name
+#define ARG_OUT(ARG_name)\
+ if (copy_to_user(arg, &ARG_name, sizeof(ARG_name))) {\
+ ret = -EFAULT;\
+ break;\
+ }
+
+#endif
+