compat_ioctl: cdrom: handle CDROM_LAST_WRITTEN

This is the only ioctl command that does not have a proper
compat handler. Making the normal implementation do the
right thing is actually very simply, so just do that by
using an in_compat_syscall() check to avoid the special
case in the pkcdvd driver.

Reviewed-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index ab4d3be..5f970a7 100644 (file)
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2663,26 +2663,6 @@ static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
        return ret;
 }
 
-#ifdef CONFIG_COMPAT
-static int pkt_compat_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
-{
-       switch (cmd) {
-       /* compatible */
-       case CDROMEJECT:
-       case CDROMMULTISESSION:
-       case CDROMREADTOCENTRY:
-       case CDROM_SEND_PACKET: /* compat mode handled in scsi_cmd_ioctl */
-       case SCSI_IOCTL_SEND_COMMAND:
-               return pkt_ioctl(bdev, mode, cmd, (unsigned long)compat_ptr(arg));
-
-       /* FIXME: no handler so far */
-       default:
-       case CDROM_LAST_WRITTEN:
-               return -ENOIOCTLCMD;
-       }
-}
-#endif
-
 static unsigned int pkt_check_events(struct gendisk *disk,
                                     unsigned int clearing)
 {
@@ -2704,9 +2684,7 @@ static const struct block_device_operations pktcdvd_ops = {
        .open =                 pkt_open,
        .release =              pkt_close,
        .ioctl =                pkt_ioctl,
-#ifdef CONFIG_COMPAT
-       .compat_ioctl =         pkt_compat_ioctl,
-#endif
+       .compat_ioctl =         blkdev_compat_ptr_ioctl,
        .check_events =         pkt_check_events,
 };
 

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 4809502..faca0f3 100644 (file)
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -3293,9 +3293,10 @@ static noinline int mmc_ioctl_cdrom_last_written(struct cdrom_device_info *cdi,
        ret = cdrom_get_last_written(cdi, &last);
        if (ret)
                return ret;
-       if (copy_to_user((long __user *)arg, &last, sizeof(last)))
-               return -EFAULT;
-       return 0;
+       if (in_compat_syscall())
+               return put_user(last, (__s32 __user *)arg);
+
+       return put_user(last, (long __user *)arg);
 }
 
 static int mmc_ioctl(struct cdrom_device_info *cdi, unsigned int cmd,