Re: [patch 0/2] x86: NMI-safe trap handlers

Andi Kleen
2010-07-14T18:56:25Z

On Wed, Jul 14, 2010 at 01:08:05PM -0400, Mathieu Desnoyers wrote:
> * Andi Kleen (andi@firstfloor.org) wrote:
> > > x86_32 cannot use vmalloc_sync_all() to sychronize the TLBs from every
> > > processes because the vmalloc area is mapped in a different address space for
> >
> > That doesn't make sense. vmalloc_all_sync() should work on 32bit too.
> > It just needs to walk all processes and fix up every page table.
>
> Yeah, I've been taken aback when Tejun told me that a few moments ago. I
> initially thought that vmalloc_sync_all() synchronized all page mappings of all
> processes on x86_32. But apparently that does not seem to be the case. I'm
> adding him in CC.

Well it worked when it was originally written. That was for the case
of a NMI handler in a module. If it doesn't work fix it. I don't
think the NMI-safe fault is really needed with it.

-Andi