Re: [PATCH] samples/livepatch: Add BPF struct_ops integration sample

[Song Liu]

On Fri, Apr 17, 2026 at 1:13 AM Miroslav Benes <mbenes@xxxxxxx> wrote:
>
> Hi,
>
> On Wed, 15 Apr 2026, Song Liu wrote:
>
> > Add a sample module that demonstrates how BPF struct_ops can work
> > together with kernel livepatch. The module livepatches
> > cmdline_proc_show() and delegates the output to a BPF struct_ops
> > callback. When no BPF program is attached, a fallback message is
> > shown; when a BPF struct_ops program is attached, it controls the
> > /proc/cmdline output via the bpf_klp_seq_write kfunc.
> >
> > This builds on the existing livepatch-sample.c pattern but shows how
> > livepatch and BPF struct_ops can be combined to make livepatched
> > behavior programmable from userspace.
> >
> > The module is built when both CONFIG_SAMPLE_LIVEPATCH and
> > CONFIG_BPF_JIT are enabled.
> >
> > Signed-off-by: Song Liu <song@xxxxxxxxxx>
>
> Interesting. It does not make me comfortable to be honest. Is this
> something we want to advertise through samples?

I can understand your concern. We don't have to add these to the
samples.

> Sashiko has comments...
> https://sashiko.dev/#/patchset/20260416001628.2062468-1-song%40kernel.org

These are valid points.

Thanks,
Song