Re: [patch 3/6] futex: Get rid of the val2 conditional dance

[André Almeida]

Às 19:34 de 23/04/21, Thomas Gleixner escreveu:
> On Fri, Apr 23 2021 at 18:40, André Almeida wrote:
> > >    
> > > -	return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
> > > +	return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3);
> >
> > Given do_futex()'s type signature, I think it makes more sense to cast
> > utime to u32.
>
> It's a pointer which you better force cast to unsigned long first.
>
> So the explicit thing would be '(u32)(unsigned long) utime' which is
> what the val2 dance stupidly did with 'int'
>
> 		val2 = (int) (unsigned long) utime;
>
> But with doing it at function call argument it's implicit, because the
>
>    unsigned long  to u32 conversion is well defined
>
> while
>
>    (u32)ptr
>
> is only well defined on 32bit.

I see, thank you for the clarification!

> Thanks,
>
>          tglx