1 files changed, 44 insertions, 23 deletions

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index e3266a64a477..393f3019ccac 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -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>
@@ -3500,7 +3501,7 @@ out:
 
 
 /* The ioctl command */
-static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
+static long st_ioctl_common(struct file *file, unsigned int cmd_in, void __user *p)
 {
 	int i, cmd_nr, cmd_type, bt;
 	int retval = 0;
@@ -3508,7 +3509,6 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
 	struct scsi_tape *STp = file->private_data;
 	struct st_modedef *STm;
 	struct st_partstat *STps;
-	void __user *p = (void __user *)arg;
 
 	if (mutex_lock_interruptible(&STp->lock))
 		return -ERESTARTSYS;
@@ -3800,14 +3800,11 @@ 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)) {
@@ -3821,16 +3818,24 @@ 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);
 	switch (cmd_in) {
+		case SCSI_IOCTL_STOP_UNIT:
+			/* unload */
+			retval = scsi_ioctl(STp->device, cmd_in, p);
+			if (!retval) {
+				STp->rew_at_close = 0;
+				STp->ready = ST_NO_TAPE;
+			}
+			return retval;
+
 		case SCSI_IOCTL_GET_IDLUN:
 		case SCSI_IOCTL_GET_BUS_NUMBER:
 			break;
+
 		default:
 			if ((cmd_in == SG_IO ||
 			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
@@ -3844,30 +3849,46 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
 				return i;
 			break;
 	}
-	retval = scsi_ioctl(STp->device, cmd_in, p);
-	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
-		STp->rew_at_close = 0;
-		STp->ready = ST_NO_TAPE;
-	}
-	return retval;
+	return -ENOTTY;
 
  out:
 	mutex_unlock(&STp->lock);
 	return retval;
 }
 
-#ifdef CONFIG_COMPAT
-static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
 {
+	void __user *p = (void __user *)arg;
 	struct scsi_tape *STp = file->private_data;
-	struct scsi_device *sdev = STp->device;
-	int ret = -ENOIOCTLCMD;
-	if (sdev->host->hostt->compat_ioctl) { 
+	int ret;
+
+	ret = st_ioctl_common(file, cmd_in, p);
+	if (ret != -ENOTTY)
+		return ret;
+
+	return scsi_ioctl(STp->device, cmd_in, p);
+}
 
-		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
+#ifdef CONFIG_COMPAT
+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;
+	int ret;
 
+	/* argument conversion is handled using put_user_mtpos/put_user_mtget */
+	switch (cmd_in) {
+	case MTIOCPOS32:
+		return st_ioctl_common(file, MTIOCPOS, p);
+	case MTIOCGET32:
+		return st_ioctl_common(file, MTIOCGET, p);
 	}
-	return ret;
+
+	ret = st_ioctl_common(file, cmd_in, p);
+	if (ret != -ENOTTY)
+		return ret;
+
+	return scsi_compat_ioctl(STp->device, cmd_in, p);
 }
 #endif