Re: arm64 pointer tagging, VA-bits, the end of the world...

[Jeremy Linton <jeremy.linton@arm.com>]

Hi,

On 08/17/2016 09:51 AM, Koen Kooi wrote:
> > Op 17 aug. 2016, om 16:39 heeft Leif Lindholm <leif.lindholm@linaro.org> het volgende geschreven:
> >
> > Hi all,
> >
> > (Sent to cross-distro with debian-arm on cc.)
> >
> > We have an 'interesting' situation ahead of us, or indeed some of us
> > have already fallen into it:

(trimming)

> > The applications we know are affected are luajit and mozjs (libv8 is
> > not a problem). But this has a follow-on cost: both of these are used
> > by other packages. Other jit/runtime packages could have their own
> > issues.
> >
> > The mozjs bug is fixed on trunk, and will hopefully make it into
> > release 49[2], but it remains to be seen if that's too late for some
> > distributions.
>
> Since mozjs is “special” when it comes to API, you have to depend on a specific version of it, so policykit hard-depends on mozjs17, which has no fixes available for the VA problem :( I’ve seen reports of systems unable to boot because of the systemd->polkit->mozjs chain. Is anyone working on fixing that?

Special, might be an understatement.

But for polkit, I've posted patches pulling it forward to mozjs24 
(needs testing!)

https://lists.freedesktop.org/archives/polkit-devel/2016-August/000487.html

With mozjs24 the mainline fix applies fairly cleanly without breaking 
the ABI.