Re: [RFC PATCH 3/4] livepatch: Add "replaceable" attribute to klp_patch

[Song Liu]

On Thu, Apr 2, 2026 at 2:26 AM Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
>
> Add a new replaceable attribute to allow the coexistence of both
> atomic-replace and non-atomic-replace livepatches. If replaceable is set to
> 0, the livepatch will not be replaced by a subsequent atomic-replace
> operation.
>
> This is a preparatory patch for following changes.

IIRC, the use case for this change is when multiple users load various
livepatch modules on the same system. I still don't believe this is the
right way to manage livepatches. That said, I won't really NACK this
if other folks think this is a useful option.

In case we really want a feature like this, shall we add a replaceable
flag to each function (klp_func)? This will give us fine granularity
control. For example, user A has a non-replaceable livepatch on
func_a; later user B wants to patch another version of func_a. Then
some logic can detect such a conflict and reject the load of user B's
livepatch. Does this make sense?

Thanks,
Song