Re: [PATCH] arch/x86: reset MXCSR to default in kernel_fpu_begin()

[Shuah Khan]

On 6/11/20 8:19 AM, Andy Lutomirski wrote:
> > On Jun 11, 2020, at 2:18 AM, Borislav Petkov <bp@xxxxxxxxx> wrote:
> >
> > ïOn Thu, Jun 11, 2020 at 10:36:08AM +0300, Petteri Aimonen wrote:
> > > Hi,
> > >
> > > > How about putting the file you frob in
> > > > /sys/kernel/debug/selftest_helpers/something_or_other.  The idea would
> > > > be that /sys/kernel/debug/selftest_helpers would be a general place
> > > > for kernel helpers needed to make selftests work.
> > >
> > > Seems like this is the consensus for now.
> > >
> > > Any opinions on whether the module should remove "selftest_helpers"
> > > directory on unloading, or not?
> > >
> > > 1) Removing would break if other test modules will use the same dir.
> > > 2) Not removing will leave the directory dangling.
> > > 3) Remove only if empty is one option, though I'm unsure how to
> > >    cleanly check if debugfs directory is empty.
> > > 4) E.g. /sys/kernel/debug/x86/ is created centrally and a symbol is
> > >    exported for its dentry. But I'm not sure if it really makes sense
> > >    to add another exported symbol just for selftest_helpers.
> >
> > I'd say you do the simple thing and cleanup after you're done, i.e.,
> > remove the dir. When something else starts using it, then it would need
> > to be taught to deal with multiple users.
>
> Seems good to me. Letâs have at least two users before we go nuts with the architecture :)

I am good with this. Let's start with simpler approach and build.
Please cc linux-kselftest and add me to the patch thread.

Thanks for this work. I think this will help expand coverage.

thanks,
-- Shuah