Re: [PATCH] virt: Add vboxguest driver for Virtual Box Guest integration

[Greg Kroah-Hartman]

On Wed, Oct 04, 2017 at 11:32:23AM +0200, Hans de Goede wrote:
> Hi,
> 
> On 03-10-17 13:41, Hans de Goede wrote:
> 
> <snip>
> 
> > > > +#define CHECK_IOCTL_IN(req)                             \
> > > > +do {                                         \
> > > > +    if ((req)->Hdr.cbIn != (sizeof((req)->Hdr) + sizeof((req)->u.In)) || \
> > > > +        (req)->Hdr.cbOut != sizeof((req)->Hdr))                 \
> > > > +        return -EINVAL;                             \
> > > > +} while (0)
> > > 
> > > Make these things functions instead of macros.
> > 
> > Turning these into functions is a good idea I will do so for v2.
> 
> Correction, I forgot that the passed in "req" macro
> argument has a different type with all the calls, so
> these cannot be changed into functions because they
> rely on sizeof on the specific type to do the size
> checks.

Don't we already have built-in checks for these types of things?  Surely
we don't require each ioctl user in the kernel to do this by
themselves...

thanks,

greg k-h