From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail11.truemail.it (mail11.truemail.it [217.194.8.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5483218C039; Fri, 15 Nov 2024 09:45:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.194.8.81 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731663922; cv=none; b=OPxn8H18h1XWgyeeG9pF1DhI+aoQx5dCZCnhfLxxQhQrxLjL0TMpECaj7PxnYpcvadsBn/Ajc8lVt7S9o6cXsO31mb1DF89NwI4l+TBYTxwov0QWRdseYkNkSbmy5V7KfDHpYNBSjl9c4pO5XsjHccL0j9/3/M4NkOoCRBrgGvc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731663922; c=relaxed/simple; bh=0Ua1gEH83HMJfF8a0QbWXqH0PMnUV9EK2uLfKohST4w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eE2s6E3k49uoVZ9gAtMu7dSjlZeTszXRRzqD1D+bXLLtEmLegr3lr8anVEhePtYAm4FtHiH6WzjvFCwLU+/4ZSwS2rh2MlAvWog2j3279ws/fAjkFEnWigYXQRKwfJi+cJRUXVUmKtzZjCkS+JPFW2o3QIxiWWtQSddpLE/ayD4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=dolcini.it; spf=pass smtp.mailfrom=dolcini.it; dkim=pass (2048-bit key) header.d=dolcini.it header.i=@dolcini.it header.b=H+rlJYCa; arc=none smtp.client-ip=217.194.8.81 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=dolcini.it Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=dolcini.it Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=dolcini.it header.i=@dolcini.it header.b="H+rlJYCa" Received: from gaggiata.pivistrello.it (93-49-2-63.ip317.fastwebnet.it [93.49.2.63]) by mail11.truemail.it (Postfix) with ESMTPA id 9516B1F9C1; Fri, 15 Nov 2024 10:45:16 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dolcini.it; s=default; t=1731663916; bh=fXgpNCrCg0QJFZPc/cMFrQdCG+CEBjUIdZW8CrlxJRc=; h=Received:From:To:Subject; b=H+rlJYCaVhZDM2yw4dLNeax0ScF4CKrvIwUI5LWN2KJAXyBIBrzz7vE2LA+f07bkN oloiYB65LBojBojUg/VFIZHNn+aSvPW6oYtRMgmio8B62LfeRUxxUppBefSCvF4fvW ddfOY4cCdebrIQ0Pt8u7qxSrsGQyAEuqXwpSlsAEkBSiB5vLNmvJy0my8YlHDOBa7/ cwx7f0vzWHGrAFttAg+4m5m2QB1zHRQCplvKJiILJvrAd1HEfkBf4D8fBMl3R+9M7/ U4A+uXIcR++NqTNUypl6l59ib1YQeUoGkbmkxhUmQO57s2fFV04eADR2MYxCd4aF/y eZh0K3QnrXqaQ== Received: by gaggiata.pivistrello.it (Postfix, from userid 1000) id 398B57F949; Fri, 15 Nov 2024 10:45:16 +0100 (CET) Date: Fri, 15 Nov 2024 10:45:16 +0100 From: Francesco Dolcini To: Greg KH , Masahiro Yamada Cc: Francesco Dolcini , Parth Pancholi , Nathan Chancellor , Nicolas Schier , Parth Pancholi , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Francesco Dolcini Subject: Re: [PATCH v2] kbuild: switch from lz4c to lz4 for compression Message-ID: References: <20241114145645.563356-1-parth105105@gmail.com> <2024111442-yeast-flail-fcea@gregkh> <20241115083940.GA3971@francesco-nb> <2024111541-antiquity-footpath-e221@gregkh> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2024111541-antiquity-footpath-e221@gregkh> On Fri, Nov 15, 2024 at 10:22:13AM +0100, Greg KH wrote: > On Fri, Nov 15, 2024 at 09:39:40AM +0100, Francesco Dolcini wrote: > > On Thu, Nov 14, 2024 at 05:02:01PM +0100, Greg KH wrote: > > > On Thu, Nov 14, 2024 at 03:56:44PM +0100, Parth Pancholi wrote: > > > > From: Parth Pancholi > > > > > > > > Replace lz4c with lz4 for kernel image compression. > > > > Although lz4 and lz4c are functionally similar, lz4c has been deprecated > > > > upstream since 2018. Since as early as Ubuntu 16.04 and Fedora 25, lz4 > > > > and lz4c have been packaged together, making it safe to update the > > > > requirement from lz4c to lz4. > > > > > > > > Consequently, some distributions and build systems, such as OpenEmbedded, > > > > have fully transitioned to using lz4. OpenEmbedded core adopted this > > > > change in commit fe167e082cbd ("bitbake.conf: require lz4 instead of > > > > lz4c"), causing compatibility issues when building the mainline kernel > > > > in the latest OpenEmbedded environment, as seen in the errors below. > > > > > > > > This change also updates the LZ4 compression commands to make it backward > > > > compatible by replacing stdin and stdout with the '-' option, due to some > > > > unclear reason, the stdout keyword does not work for lz4 and '-' works for > > > > both. In addition, this modifies the legacy '-c1' with '-9' which is also > > > > compatible with both. This fixes the mainline kernel build failures with > > > > the latest master OpenEmbedded builds associated with the mentioned > > > > compatibility issues. > > > > > > > > LZ4 arch/arm/boot/compressed/piggy_data > > > > /bin/sh: 1: lz4c: not found > > > > ... > > > > ... > > > > ERROR: oe_runmake failed > > > > > > > > Cc: stable@vger.kernel.org > > > > > > What bug does this resolve that it needs to be backported to stable > > > kernels? > > > > This is not solving any existing actual bug, and therefore there is no > > fixes tag. > > > > The issue here is that the kernel build system is using lz4c, that is > > deprecated since 2018, and now distributions are actively moving away from it. > > > > openSUSE Tumbleweed and OE already removed it, so you would not be able > > to compile a stable kernel on such distribution when using lz4 unless we > > backport such a patch. > > > > Everything should be properly documented in the commit message already. > > > > My understanding is that something like that would be a reason for > > backporting to stable, if my understanding is not correct we'll remove > > the cc:stable and send a v3. > > Please read: > https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html > for what meets stable kernel requirements. I don't think that this > patch is that. Greg, ack. Masahiro, can you please let me know if we should send a v3 with the stable tag removed or you can remove it yourself when applying? Francesco