forked from mirrors/linux
1207045da5
MTIOCPOS and MTIOCGET are incompatible between 32-bit and 64-bit user space, and traditionally have been translated in fs/compat_ioctl.c. To get rid of that translation handler, move a corresponding implementation into each of the four drivers implementing those commands. The interesting part of that is now in a new linux/mtio.h header that wraps the existing uapi/linux/mtio.h header and provides an abstraction to let drivers handle both cases easily. Using an in_compat_syscall() check, the caller does not have to keep track of whether this was called through .unlocked_ioctl() or .compat_ioctl(). Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "Kai Mäkisara" <Kai.Makisara@kolumbus.fi> Cc: linux-scsi@vger.kernel.org Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
60 lines
1.3 KiB
C
60 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_MTIO_COMPAT_H
|
|
#define _LINUX_MTIO_COMPAT_H
|
|
|
|
#include <linux/compat.h>
|
|
#include <uapi/linux/mtio.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
/*
|
|
* helper functions for implementing compat ioctls on the four tape
|
|
* drivers: we define the 32-bit layout of each incompatible structure,
|
|
* plus a wrapper function to copy it to user space in either format.
|
|
*/
|
|
|
|
struct mtget32 {
|
|
s32 mt_type;
|
|
s32 mt_resid;
|
|
s32 mt_dsreg;
|
|
s32 mt_gstat;
|
|
s32 mt_erreg;
|
|
s32 mt_fileno;
|
|
s32 mt_blkno;
|
|
};
|
|
#define MTIOCGET32 _IOR('m', 2, struct mtget32)
|
|
|
|
struct mtpos32 {
|
|
s32 mt_blkno;
|
|
};
|
|
#define MTIOCPOS32 _IOR('m', 3, struct mtpos32)
|
|
|
|
static inline int put_user_mtget(void __user *u, struct mtget *k)
|
|
{
|
|
struct mtget32 k32 = {
|
|
.mt_type = k->mt_type,
|
|
.mt_resid = k->mt_resid,
|
|
.mt_dsreg = k->mt_dsreg,
|
|
.mt_gstat = k->mt_gstat,
|
|
.mt_erreg = k->mt_erreg,
|
|
.mt_fileno = k->mt_fileno,
|
|
.mt_blkno = k->mt_blkno,
|
|
};
|
|
int ret;
|
|
|
|
if (in_compat_syscall())
|
|
ret = copy_to_user(u, &k32, sizeof(k32));
|
|
else
|
|
ret = copy_to_user(u, k, sizeof(*k));
|
|
|
|
return ret ? -EFAULT : 0;
|
|
}
|
|
|
|
static inline int put_user_mtpos(void __user *u, struct mtpos *k)
|
|
{
|
|
if (in_compat_syscall())
|
|
return put_user(k->mt_blkno, (u32 __user *)u);
|
|
else
|
|
return put_user(k->mt_blkno, (long __user *)u);
|
|
}
|
|
|
|
#endif
|