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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <86wm7a84dz.wl-maz@kernel.org>
Date: Mon, 11 Aug 2025 12:49:28 +0100
From: Marc Zyngier <maz@...nel.org>
To: fanqincui  <fanqincui@....com>
Cc: "Will Deacon" <will@...nel.org>,
	catalin.marinas@....com,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	"Fanqin Cui" <cuifq1@...natelecom.cn>,
	hanht2@...natelecom.cn
Subject: Re: [PATCH] arm64/module: Support for patching modules during runtime

On Mon, 11 Aug 2025 10:57:44 +0100,
fanqincui <fanqincui@....com> 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.