Re: [PATCH 5.4 063/355] powerpc/kvm: Fix kvm_use_magic_page

[Andreas Gruenbacher]

On Tue, Nov 16, 2021 at 1:54 AM Sasha Levin <sashal@xxxxxxxxxx> wrote:
> On Mon, Nov 15, 2021 at 06:47:41PM +0100, Andreas Gruenbacher wrote:
> >Greg,
> >
> >On Mon, Nov 15, 2021 at 6:10 PM Greg Kroah-Hartman
> ><gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> >> From: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
> >>
> >> commit 0c8eb2884a42d992c7726539328b7d3568f22143 upstream.
> >>
> >> When switching from __get_user to fault_in_pages_readable, commit
> >> 9f9eae5ce717 broke kvm_use_magic_page: like __get_user,
> >> fault_in_pages_readable returns 0 on success.
> >
> >I've not heard back from the maintainers about this patch so far, so
> >it would probably be safer to leave it out of stable for now.
>
> What do you mean exactly? It's upstream.

Mathieu Malaterre broke this test in 2018 (commit 9f9eae5ce717) but
that wasn't noticed until now (commit 0c8eb2884a42). This means that
this fix probably isn't critical, so I shouldn't be backported.

Thanks,
Andreas