Re: + futex-runtime-enable-pi-and-robust-functionality.patch added to -mm tree

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Thu, 2008-03-27 at 14:32 +1100, Benjamin Herrenschmidt wrote:
> > Hmm, not sure whether there is such code, but then it would be not too bad
> > to add
> > 
> >    if (!p)
> >       return -EFAULT;
> > 
> > to the S390 implementations which only read data and have an exception
> > fixup.
> 
> I have a different problem on some embedded powerpc's where the TLB miss
> code isn't checking for the cached pgdir pointer being NULL (which
> happens because we are early at boot and haven't activated an mm). So we
> end up either taking recursive faults or going into lalaland walking
> the page tables.
> 
> It happens on some unreleased code, I'll verify if it happens on
> 8xx/4xx/etc... in a minute, and will cook a patch if it does.

Ok, so everything released seems to be fine. It will use swapper_pg_dir
which on 32 bits will do the right thing. Pfiew ! So only some stuff I'm
still working on breaks, I'll fix it.

Cheers,
Ben.