Re: [PATCH] incorrect use of sizeof() in ioctl definitions

[Andries Brouwer]

On Tue, Sep 30, 2003 at 11:25:56PM +0100, Matthew Wilcox wrote:
> On Tue, Sep 30, 2003 at 02:08:05PM -0700, Andrew Morton wrote:
> > Arun Sharma <arun.sharma@xxxxxxxxx> wrote:
> > >
> > > Some drivers seem to use macros such as _IOR/_IOW in a way that ends up
> > > calling the sizeof() operator twice. For eg:
> > > 
> > > -#define FBIO_ATY128_GET_MIRROR	_IOR('@', 1, sizeof(__u32*))
> > > +#define FBIO_ATY128_GET_MIRROR	_IOR('@', 1, __u32*)

But this changes the define. You want

#define FBIO_ATY128_GET_MIRROR	_IOR_BAD('@', 1, __u32*)

> +#define _IOR(type,nr,size)     _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size)
> ))
> +#define _IOR_BAD(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size))

Something else we should do is to change all occurrences of 'size'
here into 'argtype'. All this nonsense came because of the bad choice
of identifier.

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