Re: [RFC PATCH 0/4] trace, livepatch: Allow kprobe return overriding for livepatched functions

Yafang Shao
2026-04-06T10:58:08Z

On Mon, Apr 6, 2026 at 1:36 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Thu, Apr 02, 2026 at 05:26:03PM +0800, Yafang Shao wrote:
> > Livepatching allows for rapid experimentation with new kernel features
> > without interrupting production workloads.
>
> Myabe it allows, or based on the rest of the mail not quite. But that
> is certainly not the intent at all, the intent is to fix critical
> bugs without downtime.
>
> > However, static livepatches lack
> > the flexibility required to tune features based on task-specific attributes,
> > such as cgroup membership, which is critical in multi-tenant k8s
> > environments. Furthermore, hardcoding logic into a livepatch prevents
> > dynamic adjustments based on the runtime environment.
> >
> > To address this, we propose a hybrid approach using BPF. Our production use
> > case involves:
> >
> > 1. Deploying a Livepatch function to serve as a stable BPF hook.
> >
> > 2. Utilizing bpf_override_return() to dynamically modify the return value
> > of that hook based on the current task's context.
>
> Whol f**. now. Is this a delayed April 1st post?

You're already in my spam list. Don't expect any further replies. Feel
free to keep your verbose rubbish to yourself.

--
Regards
Yafang