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[23.128.96.18]) by mx.google.com with ESMTP id q24si1096944edg.244.2021.01.20.09.04.13; Wed, 20 Jan 2021 09:04:49 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=rkq48BkM; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732743AbhATRCm (ORCPT + 99 others); Wed, 20 Jan 2021 12:02:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391504AbhATRCV (ORCPT ); Wed, 20 Jan 2021 12:02:21 -0500 Received: from mail-yb1-xb29.google.com (mail-yb1-xb29.google.com [IPv6:2607:f8b0:4864:20::b29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B51E4C061757 for ; Wed, 20 Jan 2021 09:01:40 -0800 (PST) Received: by mail-yb1-xb29.google.com with SMTP id k132so12965686ybf.2 for ; Wed, 20 Jan 2021 09:01:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Zip1YNjoZXFgZ8lroULvsuiHYsaE4S6un/EkVy9J4nQ=; b=rkq48BkM1/dH4LDxPLmEIvYSQWvXf93lUmaFUZWrmGoO28g03x1j237DGaFFGSvbQq Z6kB2gIZs2p1/3sywlp10v80pisStM6DN2HvXhVpiKCEBdAI6oCZe+3dVAED9NDiuwLr /JPQNXxrTknEUZ2MpZvfjbOJpQ/vtErl5pxrCM9rFdzXLyJaOJ6P/oCq+XBcQhQQhSqE MpcdejhHwv6xDhx2agOUT3wah8og0hbLsNimRIbUIsnt6fPcODI4Cb5XJfPHk/uv9kbK auKQ1LnGLx9w3uR2DzDPCH1sv3HAA4JBMq3itwh1YDat+DtWVBwiIciZTHqIpZbHnlHF 9qNg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Zip1YNjoZXFgZ8lroULvsuiHYsaE4S6un/EkVy9J4nQ=; b=CpQxW5DuLZH3z8br6K/C99pr2SlAAY79pLIYxGIhD1slGE6KUSnhl70kfGz2Nf+FOa aL4Kr+L97tE75hlneMwevRTuYRsLf3L6wjuD4gtotd1DCONLriR7N4lYU1fb0cGGFmnx z11bpQ0hENMxZfslJJhFyOzxx/6EGZFPmkE2fNHbMaQ5jHn57gkoPgzdgiPD4aqF6yTt 6k9AT6FTOsgW6uZgyOq6STkwlqlVDA4DtAdXRO92R51h41u3wpFJrbUvvuMM9UtwgA9L iWkVE4nNhPcfIIiFkczyNSuiM6SB/PTJu3A2DMbF9ICRKexRkKGBhF0/OMcHysH6FwGe X/ug== X-Gm-Message-State: AOAM531DK1TS4mQa5wWW4j2O1zxgmNVgjhwUYAINS88w/CXPifvK+PXZ b870YJFMXZQK71utDLDgtFATsGTAMJBd2db8Ztm+qw== X-Received: by 2002:a25:8b8b:: with SMTP id j11mr13833445ybl.310.1611162099713; Wed, 20 Jan 2021 09:01:39 -0800 (PST) MIME-Version: 1.0 References: <20210108003035.1930475-1-willmcvicker@google.com> <20210120142526.GA3759754@infradead.org> In-Reply-To: <20210120142526.GA3759754@infradead.org> From: Saravana Kannan Date: Wed, 20 Jan 2021 09:01:03 -0800 Message-ID: Subject: Re: [PATCH v5] modules: introduce the MODULE_SCMVERSION config To: Christoph Hellwig Cc: Will McVicker , Jessica Yu , Masahiro Yamada , Michal Marek , Greg Kroah-Hartman , LKML , Linux Kbuild mailing list , Android Kernel Team Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 20, 2021 at 6:26 AM Christoph Hellwig wrote: > > On Fri, Jan 08, 2021 at 12:30:35AM +0000, Will McVicker wrote: > > For example, we have a CI setup that tests new kernel changes on the > > hikey960 and db845c devices without updating their kernel modules. When > > these tests fail, we need to be able to identify the exact device > > configuration the test was using. By including MODULE_SCMVERSION, we can > > identify the exact kernel and modules' SCM versions for debugging the > > failures. > > Sorry, but this still has no business in the upstream kernel as every > change to the kernel is free to just change any API. Sure, and this patch is making no claims one way or the other on that topic. > That is whatever > you test there is a completely unsupported setup. Plenty of distributions maintain stable kernels based on LTS. We've done that too and we are able to do LTS kernel binary updates (so better security) without waiting around for the modules to get updated. Keep in mind, that not all modules might be updated at the same time either. That's something that's definitely feasible and works. And if the API changes, MODVERSIONS catches + CI helps catch them. And if something slips in and things fail, we want to find out what kernel source was used vs what module source was used to debug the problem. This is all relevant even for in-tree modules. > More importantly the "scmversion" of a module simply does not matter, > as we only support modules from the kernel tree and it thus must be the > kernel version. > be supported. This is all talking about only in-tree modules. If you update the kernel vs the modules separately, the scmversion does matter. Also, by your argument, the vermagic or srcversion properties in a module shouldn't be there either. > You are still trying to sneak out of tree module infrastructure in here > with a bad cover story. Please stop doing that. If Will needs to maintain a downstream patch for adding out-of-tree module support, maintaining this additional patch isn't going to significantly increase his work. But he's trying to upstream at least the part that's useful for upstream. This is still a real problem for a device/board that's fully upstream. Please stop ignoring real upstream problems just because it can also be a problem for out of tree modules. This is not how we encourage folks to upstream their changes. -Saravana