On Tue, Apr 30, 2019 at 05:54:49PM +0100, Peter Maydell wrote:
> On Thu, 25 Apr 2019 at 14:21, Cornelia Huck <coh...@redhat.com> wrote:
[...]
> > - SCSIDevice *sd = (SCSIDevice *) object_dynamic_cast(OBJECT(dev_st),
> > -
> > TYPE_SCSI_DEVICE);
> > -
> > - if (sd) {
> > + switch (devtype) {
> > + case CCW_DEVTYPE_SCSI:
> > + sd = (SCSIDevice *) object_dynamic_cast(OBJECT(dev_st),
> > +
> > TYPE_SCSI_DEVICE);
>
> Coverity doesn't like the use of object_dynamic_cast() without a
> check that the return value isn't NULL before we dereference
> it a few lines further down.
>
> I think that if we know this cast must always succeed, we
> could instead just write
> SCSIDevice *sd = SCSI_DEVICE(dev_st);
>
> On the other hand if the cast might not succeed because dev_st
> isn't necessarily of the right type, then we should check it
> for NULL and handle that appropriately.
s390_get_ccw_device() will set devtype=CCW_DEVTYPE_SCSI only if
dev_st is TYPE_SCSI_DEVICE, so the cast must always succeed and
we should use SCSI_DEVICE(dev_st) here.
--
Eduardo
