On Fri, 28 Sep 2018, Andy Lutomirski wrote:
> On Fri, Sep 28, 2018 at 7:53 AM Martin Schwidefsky <[email protected]>
> wrote:
> > On Fri, 28 Sep 2018 07:11:44 -0700 Andy Lutomirski <[email protected]>
> > wrote:
> >
> > > There’s another way to skin this cat: keep KERNEL_DS but pass a valid
> > > pointer.
> > > I don’t suppose you remember why you didn’t do that?
> >
> > No, I don't remember. To use a valid kernel pointer with KERNEL_DS and
> > then test for == 0 (vs -ENOSYS) imho should work.
> >
>
> There may be a much nicer solution. Unless I missed something, only
> mips and xtensa even have the possibility of cmpxchg being missing.
> We could just make those arches supply a futex-detecting helper.
That makes sense.
Thanks,
tglx
