Re: [RFC PATCH 06/16] x86/split_lock: Save #AC setting for split lock in firmware in boot time and restore the setting in reboot

From: Alan Cox
Date: Fri Jun 22 2018 - 11:11:20 EST


On Thu, 2018-06-21 at 21:58 +0200, Peter Zijlstra wrote:
> On Sun, May 27, 2018 at 08:45:55AM -0700, Fenghua Yu wrote:
> > Firmware may contain split locked instructions.
>
> I think that's the wrong attitude. You should mandate in your BIOS
> development guide that Firmware _MUST_NOT_ contain unaligned LOCK
> prefixed instructions.
>

In the longer term I would agree entirely with that sentiment.

Alan