[PATCH v5 09/11] loop: Rework lo_ioctl() __user argument casting

Martijn Coenen
2020-05-13T13:39:14Z

In preparation for a new ioctl that needs to copy_from_user(); makes the
code easier to read as well.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martijn Coenen <maco@android.com>
---
drivers/block/loop.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 4dc11d954169..31f10da4945e 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1634,6 +1634,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
struct loop_device *lo = bdev->bd_disk->private_data;
+ void __user *argp = (void __user *) arg;
int err;

switch (cmd) {
@@ -1646,21 +1647,19 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
case LOOP_SET_STATUS:
err = -EPERM;
if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) {
- err = loop_set_status_old(lo,
- (struct loop_info __user *)arg);
+ err = loop_set_status_old(lo, argp);
}
break;
case LOOP_GET_STATUS:
- return loop_get_status_old(lo, (struct loop_info __user *) arg);
+ return loop_get_status_old(lo, argp);
case LOOP_SET_STATUS64:
err = -EPERM;
if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) {
- err = loop_set_status64(lo,
- (struct loop_info64 __user *) arg);
+ err = loop_set_status64(lo, argp);
}
break;
case LOOP_GET_STATUS64:
- return loop_get_status64(lo, (struct loop_info64 __user *) arg);
+ return loop_get_status64(lo, argp);
case LOOP_SET_CAPACITY:
case LOOP_SET_DIRECT_IO:
case LOOP_SET_BLOCK_SIZE:
--
2.26.2.645.ge9eca65c58-goog