Re: [PATCH 2/2] livepatch: Allow loading modules on architectures without HAVE_RELIABLE_STACKTRACE

From: Miroslav Benes
Date: Fri Dec 22 2017 - 08:13:10 EST


On Thu, 21 Dec 2017, Petr Mladek wrote:

> On Fri 2017-12-08 18:25:23, Miroslav Benes wrote:
> > Now that immediate feature was removed, it is not possible to load
> > livepatch modules on architectures without HAVE_RELIABLE_STACKTRACE. Fix
> > it by removing guilty check in klp_register_patch().
> >
> > The architectures without HAVE_RELIABLE_STACKTRACE will now rely only on
> > kernelspace/userspace boundary switching, the (fake) signal and force
> > feature.
>
> I do not thing that this is a good idea. It encourages people to use
> the force feature. They might get used to it.
>
> If people are going to provide livepatches, they should be capable
> enough to provide a kernel where it is allowed. IMHO, the upstream
> kernel should not support bad/dirty practices out of box.

You're probably right.

It is true that with immediate gone the only reasonable thing for all
supported architectures is to provide HAVE_RELIABLE_STACKTRACE.

Miroslav