+EXPORT_SYMBOL(dvb_unregister_adapter);
+
+/* if the miracle happens and "generic_usercopy()" is included into
+ the kernel, then this can vanish. please don't make the mistake and
+ define this as video_usercopy(). this will introduce a dependecy
+ to the v4l "videodev.o" module, which is unnecessary for some
+ cards (ie. the budget dvb-cards don't need the v4l module...) */
+int dvb_usercopy(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg,
+ int (*func)(struct inode *inode, struct file *file,
+ unsigned int cmd, void *arg))
+{
+ char sbuf[128];
+ void *mbuf = NULL;
+ void *parg = NULL;
+ int err = -EINVAL;
+
+ /* Copy arguments into temp kernel buffer */
+ switch (_IOC_DIR(cmd)) {
+ case _IOC_NONE:
+ /*
+ * For this command, the pointer is actually an integer
+ * argument.
+ */
+ parg = (void *) arg;
+ break;
+ case _IOC_READ: /* some v4l ioctls are marked wrong ... */
+ case _IOC_WRITE:
+ case (_IOC_WRITE | _IOC_READ):
+ if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
+ parg = sbuf;
+ } else {
+ /* too big to allocate from stack */
+ mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
+ if (NULL == mbuf)
+ return -ENOMEM;
+ parg = mbuf;
+ }
+
+ err = -EFAULT;
+ if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
+ goto out;
+ break;
+ }
+
+ /* call driver */
+ if ((err = func(inode, file, cmd, parg)) == -ENOIOCTLCMD)
+ err = -EINVAL;
+
+ if (err < 0)
+ goto out;
+
+ /* Copy results into user buffer */
+ switch (_IOC_DIR(cmd))
+ {
+ case _IOC_READ:
+ case (_IOC_WRITE | _IOC_READ):
+ if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
+ err = -EFAULT;
+ break;
+ }