Re: [patch 20/24] x86/speculation: Split out TIF update

From: Jiri Kosina
Date: Wed Nov 28 2018 - 01:05:25 EST

On Tue, 27 Nov 2018, Thomas Gleixner wrote:

> > Does it really have to?
> >
> > We need this special handling only if the next task has TIF_SPEC_UPDATE
> > set, which is one-off event globally (when seccomp marks all its threads
> > so due to seccomp filter change), and once all the TIF_SPEC_UPDATE tasks
> > schedule at least once, we're in a consistent state again and don't need
> > this, as every running task will then have its TIF consistent with MSR
> > value.
> And how so? You set the bits is spec_flags. And then you set the TIF_UPDATE
> bit which is evaluated once.

Yeah, that was a complete brainfart on my side, sorry for the noise,
disregard that crap. I blame it all on the dentist appointment I went
through before writing the patch :p


Jiri Kosina