Commit 1207045d authored by Arnd Bergmann's avatar Arnd Bergmann

compat_ioctl: move tape handling into drivers

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: default avatarHeiko 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: default avatarArnd Bergmann <arnd@arndb.de>
parent 01b8bca8
......@@ -19,6 +19,7 @@
#define IDETAPE_VERSION "1.20"
#include <linux/compat.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
......@@ -1407,14 +1408,10 @@ static long do_idetape_chrdev_ioctl(struct file *file,
if (tape->drv_write_prot)
mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
return -EFAULT;
return 0;
return put_user_mtget(argp, &mtget);
case MTIOCPOS:
mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
return -EFAULT;
return 0;
return put_user_mtpos(argp, &mtpos);
default:
if (tape->chrdev_dir == IDETAPE_DIR_READ)
ide_tape_discard_merge_buffer(drive, 1);
......@@ -1432,6 +1429,22 @@ static long idetape_chrdev_ioctl(struct file *file,
return ret;
}
static long idetape_chrdev_compat_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
long ret;
if (cmd == MTIOCPOS32)
cmd = MTIOCPOS;
else if (cmd == MTIOCGET32)
cmd = MTIOCGET;
mutex_lock(&ide_tape_mutex);
ret = do_idetape_chrdev_ioctl(file, cmd, arg);
mutex_unlock(&ide_tape_mutex);
return ret;
}
/*
* Do a mode sense page 0 with block descriptor and if it succeeds set the tape
* block size with the reported value.
......@@ -1886,6 +1899,8 @@ static const struct file_operations idetape_fops = {
.read = idetape_chrdev_read,
.write = idetape_chrdev_write,
.unlocked_ioctl = idetape_chrdev_ioctl,
.compat_ioctl = IS_ENABLED(CONFIG_COMPAT) ?
idetape_chrdev_compat_ioctl : NULL,
.open = idetape_chrdev_open,
.release = idetape_chrdev_release,
.llseek = noop_llseek,
......
......@@ -341,14 +341,14 @@ tapechar_release(struct inode *inode, struct file *filp)
*/
static int
__tapechar_ioctl(struct tape_device *device,
unsigned int no, unsigned long data)
unsigned int no, void __user *data)
{
int rc;
if (no == MTIOCTOP) {
struct mtop op;
if (copy_from_user(&op, (char __user *) data, sizeof(op)) != 0)
if (copy_from_user(&op, data, sizeof(op)) != 0)
return -EFAULT;
if (op.mt_count < 0)
return -EINVAL;
......@@ -392,9 +392,7 @@ __tapechar_ioctl(struct tape_device *device,
if (rc < 0)
return rc;
pos.mt_blkno = rc;
if (copy_to_user((char __user *) data, &pos, sizeof(pos)) != 0)
return -EFAULT;
return 0;
return put_user_mtpos(data, &pos);
}
if (no == MTIOCGET) {
/* MTIOCGET: query the tape drive status. */
......@@ -424,15 +422,12 @@ __tapechar_ioctl(struct tape_device *device,
get.mt_blkno = rc;
}
if (copy_to_user((char __user *) data, &get, sizeof(get)) != 0)
return -EFAULT;
return 0;
return put_user_mtget(data, &get);
}
/* Try the discipline ioctl function. */
if (device->discipline->ioctl_fn == NULL)
return -EINVAL;
return device->discipline->ioctl_fn(device, no, data);
return device->discipline->ioctl_fn(device, no, (unsigned long)data);
}
static long
......@@ -445,7 +440,7 @@ tapechar_ioctl(struct file *filp, unsigned int no, unsigned long data)
device = (struct tape_device *) filp->private_data;
mutex_lock(&device->mutex);
rc = __tapechar_ioctl(device, no, data);
rc = __tapechar_ioctl(device, no, (void __user *)data);
mutex_unlock(&device->mutex);
return rc;
}
......@@ -455,23 +450,17 @@ static long
tapechar_compat_ioctl(struct file *filp, unsigned int no, unsigned long data)
{
struct tape_device *device = filp->private_data;
int rval = -ENOIOCTLCMD;
unsigned long argp;
long rc;
/* The 'arg' argument of any ioctl function may only be used for
* pointers because of the compat pointer conversion.
* Consider this when adding new ioctls.
*/
argp = (unsigned long) compat_ptr(data);
if (device->discipline->ioctl_fn) {
mutex_lock(&device->mutex);
rval = device->discipline->ioctl_fn(device, no, argp);
mutex_unlock(&device->mutex);
if (rval == -EINVAL)
rval = -ENOIOCTLCMD;
}
if (no == MTIOCPOS32)
no = MTIOCPOS;
else if (no == MTIOCGET32)
no = MTIOCGET;
return rval;
mutex_lock(&device->mutex);
rc = __tapechar_ioctl(device, no, compat_ptr(data));
mutex_unlock(&device->mutex);
return rc;
}
#endif /* CONFIG_COMPAT */
......
......@@ -22,6 +22,7 @@ static const char *verstr = "20160209";
#include <linux/module.h>
#include <linux/compat.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
......@@ -3800,14 +3801,11 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
if (STp->cleaning_req)
mt_status.mt_gstat |= GMT_CLN(0xffffffff);
i = copy_to_user(p, &mt_status, sizeof(struct mtget));
if (i) {
retval = (-EFAULT);
retval = put_user_mtget(p, &mt_status);
if (retval)
goto out;
}
STp->recover_reg = 0; /* Clear after read */
retval = 0;
goto out;
} /* End of MTIOCGET */
if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
......@@ -3821,9 +3819,7 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
goto out;
}
mt_pos.mt_blkno = blk;
i = copy_to_user(p, &mt_pos, sizeof(struct mtpos));
if (i)
retval = (-EFAULT);
retval = put_user_mtpos(p, &mt_pos);
goto out;
}
mutex_unlock(&STp->lock);
......@@ -3857,14 +3853,26 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
}
#ifdef CONFIG_COMPAT
static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
static long st_compat_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
{
void __user *p = compat_ptr(arg);
struct scsi_tape *STp = file->private_data;
struct scsi_device *sdev = STp->device;
int ret = -ENOIOCTLCMD;
/* argument conversion is handled using put_user_mtpos/put_user_mtget */
switch (cmd_in) {
case MTIOCTOP:
return st_ioctl(file, MTIOCTOP, (unsigned long)p);
case MTIOCPOS32:
return st_ioctl(file, MTIOCPOS, (unsigned long)p);
case MTIOCGET32:
return st_ioctl(file, MTIOCGET, (unsigned long)p);
}
if (sdev->host->hostt->compat_ioctl) {
ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
}
return ret;
......
......@@ -27,7 +27,6 @@
#include <linux/file.h>
#include <linux/ppp-ioctl.h>
#include <linux/if_pppox.h>
#include <linux/mtio.h>
#include <linux/tty.h>
#include <linux/vt_kern.h>
#include <linux/raw.h>
......@@ -361,73 +360,6 @@ static int ppp_scompress(struct file *file, unsigned int cmd,
return do_ioctl(file, PPPIOCSCOMPRESS, (unsigned long) odata);
}
#ifdef CONFIG_BLOCK
struct mtget32 {
compat_long_t mt_type;
compat_long_t mt_resid;
compat_long_t mt_dsreg;
compat_long_t mt_gstat;
compat_long_t mt_erreg;
compat_daddr_t mt_fileno;
compat_daddr_t mt_blkno;
};
#define MTIOCGET32 _IOR('m', 2, struct mtget32)
struct mtpos32 {
compat_long_t mt_blkno;
};
#define MTIOCPOS32 _IOR('m', 3, struct mtpos32)
static int mt_ioctl_trans(struct file *file,
unsigned int cmd, void __user *argp)
{
/* NULL initialization to make gcc shut up */
struct mtget __user *get = NULL;
struct mtget32 __user *umget32;
struct mtpos __user *pos = NULL;
struct mtpos32 __user *upos32;
unsigned long kcmd;
void *karg;
int err = 0;
switch(cmd) {
case MTIOCPOS32:
kcmd = MTIOCPOS;
pos = compat_alloc_user_space(sizeof(*pos));
karg = pos;
break;
default: /* MTIOCGET32 */
kcmd = MTIOCGET;
get = compat_alloc_user_space(sizeof(*get));
karg = get;
break;
}
if (karg == NULL)
return -EFAULT;
err = do_ioctl(file, kcmd, (unsigned long)karg);
if (err)
return err;
switch (cmd) {
case MTIOCPOS32:
upos32 = argp;
err = convert_in_user(&pos->mt_blkno, &upos32->mt_blkno);
break;
case MTIOCGET32:
umget32 = argp;
err = convert_in_user(&get->mt_type, &umget32->mt_type);
err |= convert_in_user(&get->mt_resid, &umget32->mt_resid);
err |= convert_in_user(&get->mt_dsreg, &umget32->mt_dsreg);
err |= convert_in_user(&get->mt_gstat, &umget32->mt_gstat);
err |= convert_in_user(&get->mt_erreg, &umget32->mt_erreg);
err |= convert_in_user(&get->mt_fileno, &umget32->mt_fileno);
err |= convert_in_user(&get->mt_blkno, &umget32->mt_blkno);
break;
}
return err ? -EFAULT: 0;
}
#endif /* CONFIG_BLOCK */
/* Bluetooth ioctls */
#define HCIUARTSETPROTO _IOW('U', 200, int)
#define HCIUARTGETPROTO _IOR('U', 201, int)
......@@ -479,8 +411,6 @@ IGNORE_IOCTL(VT_GETMODE)
*/
COMPATIBLE_IOCTL(_IOR('p', 20, int[7])) /* RTCGET */
COMPATIBLE_IOCTL(_IOW('p', 21, int[7])) /* RTCSET */
/* Little m */
COMPATIBLE_IOCTL(MTIOCTOP)
#ifdef CONFIG_BLOCK
/* md calls this on random blockdevs */
IGNORE_IOCTL(RAID_VERSION)
......@@ -846,9 +776,6 @@ static long do_ioctl_trans(unsigned int cmd,
return sg_ioctl_trans(file, cmd, argp);
case SG_GET_REQUEST_TABLE:
return sg_grt_trans(file, cmd, argp);
case MTIOCGET32:
case MTIOCPOS32:
return mt_ioctl_trans(file, cmd, argp);
#endif
}
......
/* 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
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