ieee1394: raw1394: Fix read() for 32bit userland on 64bit kernel

read() always failed with -EFAULT.  This was happening due to
raw1394_compat_read copying data to wrong location - access_ok always
failed as 'r' is kernel address, not user.  Whole function just tried to
copy data from 'r' to 'r', which is not good.

Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Acked-by: Dan Dennedy <dan@dennedy.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (split into 3 patches)

drivers/ieee1394/raw1394.c

@@ -459,7 +459,7 @@ static const char __user *raw1394_compat_write(const char __user *buf)
 static int
 raw1394_compat_read(const char __user *buf, struct raw1394_request *r)
 {
-	struct compat_raw1394_req __user *cr = (typeof(cr)) r;
+	struct compat_raw1394_req __user *cr = (typeof(cr)) buf;
 	if (!access_ok(VERIFY_WRITE, cr, sizeof(struct compat_raw1394_req)) ||
 	    P(type) ||
 	    P(error) ||