On Wed, Oct 04, 2017 at 12:23:41PM +0200, Arnd Bergmann wrote: > On Wed, Oct 4, 2017 at 12:11 PM, Greg Kroah-Hartman > <[email protected]> wrote: > > 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... > > No other driver uses this kind of header for the ioctl structures, > usually we just rely on the ioctl command number to encode the > size, or we copy a fixed length.
Then why can't we do the same thing here as well?
