Re: [PATCH 0/2] livepatch: Move tests from lib/livepatch to selftests/livepatch

[Petr Mladek <pmladek@suse.com>]

On Fri 2022-06-10 09:06:16, Joe Lawrence wrote:
> On 6/9/22 4:16 PM, Shuah Khan wrote:
> > On 6/3/22 8:32 AM, Marcos Paulo de Souza wrote:
> >> Hi there,
> >>
> >> The first patch moves the current livepatch tests to selftests,
> >> allowing it
> >> be better suited to contain more complex tests, like using userspace C
> >> code
> >> to use the livepatched kernel code. As a bonus it allows to use
> >> "gen_tar" to export the livepatch selftests, rebuild the modules by
> >> running make in selftests/livepatch directory and simplifies the process
> >> of creating and debugging new selftests.
> >>
> > 
> > In general selftests don't include modules. We keep test modules under lib.
> > One of the reasons is that modules have dependencies on the kernel and
> > should
> > be built when kernel is built.
> > 
> > I don't fully buy the argument that moving modules under selftest would
> > simplify
> > the process.
> > 
> 
> Hi Shuah,
> 
> I see that there is tools/testing/selftests/bpf/bpf_testmod/ which
> claims to be a "conceptually out-of-tree module".  Would similarly
> moving livepatch test modules under tools/ give us flexibility to write
> them build for multiple kernel versions?  Then one could theoretically
> build and run the latest, greatest selftests against older kernels
> (assuming the associate script/module/kernel supports the idea)?

+1

Another motivation is that the new selftest also needs
an executable binary. It would be nice to handle both modules
and binaries the same way.

Honestly, lib/* is a mess. It mixes real functionality and test
modules. The relation between the modules and tools/testing/*
is far from clear. IMHO, it would be more clean to have the related
stuff together.

Of course, we could not move all test modules from lib/* easily.
Some of them might be used on its own or even as built-in
tests. But preventing the move looks like a step in
the wrong direction to me.

Best Regards,
Petr