From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AD56320F082; Tue, 4 Feb 2025 13:52:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738677127; cv=none; b=hJnhYdQrp41xsAYR78vyjwAbAbUpB0qeG134IJUrLWYxmVQLQa7oRoNQ+e1TVj6nAyIUrfetT322HHExF8wFrNs1JAqIVn0TkQ7sOJB7Dcb+uhnnBVdcaG8zx2DeIymVJ11frJAdHZz8auLiBvMALqwIX/hZDdjw3rvTurFcSPA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738677127; c=relaxed/simple; bh=hID8WMBLMfeNex2lw7neHRzziXNYlPbmFHtmRj1zX70=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JALvq2dC2q24wlSzONqPIrWsUrDGG/kY4l+/awsj9dJjfDH8KSYoIXCiBvg/RN2U/R3HjcCu5cX4hPhDrWahL0eAfN3EDBeAEd+/fQTy8MLy7bX33eBBUqgW92zlP00AagjHIWSkE4s5+FLRKBxIud/RPcxJOaBJ+uohG4ABa4I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lqQYMe2x; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="lqQYMe2x" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7DDCEC4CEDF; Tue, 4 Feb 2025 13:52:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1738677127; bh=hID8WMBLMfeNex2lw7neHRzziXNYlPbmFHtmRj1zX70=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lqQYMe2x4S93kKMyeDC03NhIRPdTRFlbjLLX0Vt17LSbNyFtgRnvshtBKfQZsZ4NE OQ90Lg3wmqW4tW4L2vKKkomygLljUlF8aepxko24d+sGmh9EE4mx6Wj9zNKJGdz52T tY6ZxzavNh1ugt+XMmd9kPmWl2DUaDurUIMVjlts= Date: Tue, 4 Feb 2025 14:52:03 +0100 From: Greg KH To: Masahiro Yamada Cc: Salvatore Bonaccorso , 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: <2025020457-nanny-reward-06bd@gregkh> 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Mon, Feb 03, 2025 at 11:44:50AM +0900, Masahiro Yamada wrote: > On Sun, Feb 2, 2025 at 6:00 PM Salvatore Bonaccorso wrote: > > > > Hi Greg, hi Yamada, > > > > On Sat, Nov 16, 2024 at 04:51:48PM +0900, Masahiro Yamada wrote: > > > On Fri, Nov 15, 2024 at 6:45 PM Francesco Dolcini wrote: > > > > > > > > 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? > > > > > > > > > > I applied this with the stable tag removed. > > > Thanks. > > > > > > (I guess someone may want to backport this eventually, > > > as such distros cannot build stable kernels with ld4 compression.) > > > > Yes please :) > > Agree. > This should be back-ported. Ok, now queued up, thanks. greg k-h