Re: [PATCH] arm64/module: Support for patching modules during runtime

From: Marc Zyngier
Date: Mon Aug 11 2025 - 07:49:45 EST


On Mon, 11 Aug 2025 10:57:44 +0100,
fanqincui <fanqincui@xxxxxxx> wrote:
>
> >Well, you can't know about that. We patch basic primitives such as
> >atomics, system register access, and plenty of other things. These
> >things need to interoperate with the rest of the kernel.
> >
> >It's already difficult to guarantee inside the kernel itself. Having
> >it in random modules will be even harder.
> >
>
>
> Okay, so the kernel patches you mentioned, are they already patched
> when the module is installed?

Yes.

> This doesn't conflict with the kernel patching.

In what sense?

> I mean, the specific patching within the module is up to me.

No.

> If the chicken-and-egg problem you mentioned exist, module
> developers should avoid it in their own code. 

We're not in the business of making the kernel more fragile and hard
to maintain than it already is. So either it *always* works, or it is
completely disallowed.

> I think the kernel should provide modules with the ability to patch
> themselves, right?

Only if it is safe to do so. Which is why I asked a question in my
initial reply, which you still haven't answered.

M.

--
Without deviation from the norm, progress is not possible.