Re: [PATCH v7 10/25] arm64: compat: Add vDSO

Will Deacon
2019-07-10T09:12:54Z

On Wed, Jul 10, 2019 at 10:58:25AM +0200, Thomas Gleixner wrote:
> On Wed, 10 Jul 2019, Will Deacon wrote:
> > On Tue, Jul 09, 2019 at 09:02:54PM -0700, John Stultz wrote:
> > > I tried to bisect things down a bit, but as some later fixes are
> > > required (at one point, date was returning the start epoch and never
> > > increasing), this hasn't worked too well. But I'm guessing since I
> > > see: "CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will
> > > not be built", and the system is half working, I'm guessing this is an
> > > issue with just the 32bit code failing. While I can try to sort out
> > > the proper CROSS_COMPILE_COMPAT in my build environment, I assume
> > > userland shouldn't be crashing if that value isn't set.
> > >
> > > Any chance this issue has already been raised?
> >
> > First I've seen of it, although Vincenzo is likely to know better than me.
> > In the meantime, please can you share your .config?
>
> I think the key is: CROSS_COMPILE_COMPAT not defined or empty. And then run
> 32bit userspace.

The part I was wondering about is whether the vectors page has been disabled
at the same time, since I'm fairly sure I've already been running with the
above (but I can easily double-check).

Will