Re: [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled

Arjan van de Ven
2006-05-21T14:11:05Z

On Sat, 2006-05-20 at 02:26 -0700, Andrew Morton wrote:
> Ingo Molnar <mingo@elte.hu> wrote:
> >
> >
> > * Linus Torvalds <torvalds@osdl.org> wrote:
> >
> > > > Well that patch took a machine from working to non-working. Pretty serious
> > > > stuff. We should get to the bottom of the problem so we can assess the
> > > > risk and impact, no?
> > >
> > > Yes. And it would be good to have a way to turn it off - either
> > > globally of by some per-process setup (eg off by default, but turn on
> > > when doing some magic).
> > >
> > > The per-process one would be the harder one, because it would require
> > > the fixmap entry, but not globally. So I suspect the only practical
> > > thing would be to have it be a kernel boot-time option.
> >
> > below is a patch that adds the vdso=0 boot option from exec-shield and
> > the /proc/sys/vm/vdso_enabled per-system sysctl.
> >
> > Andrew, could you try this - do newly started processes work fine if you
> > re-enable the vdso after booting with vdso=0?
>
> vmm:/home/akpm# echo 1 > /proc/sys/vm/vdso_enabled
> vmm:/home/akpm#
> vmm:/home/akpm> ls -l
> zsh: segmentation fault ls -l

any chance to get a coredump ?