From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D59FAC433F5 for ; Mon, 30 May 2022 19:37:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243074AbiE3Th2 (ORCPT ); Mon, 30 May 2022 15:37:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233186AbiE3Th0 (ORCPT ); Mon, 30 May 2022 15:37:26 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A40F953700; Mon, 30 May 2022 12:37:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 5A417B80EF4; Mon, 30 May 2022 19:37:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 801CAC385B8; Mon, 30 May 2022 19:37:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1653939443; bh=N++pdaqxxR3mfmUMBn2HNu9rkyihptoWh1TrpMRBdys=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=xztIAB4G5ZyIVNwBARbpTyYCuuretroT66NXzmhntA8dW2REk1RzcHREzSeqa0dUJ +T/Csb4a2YlAPLSIhFbfUm8j1cVt3r7/78CVFpKXQxukReAOMDb6anzvCzYN7CRUHu N1S4FOZKyy2uO8RgOnAuMvqj3ffycmVnHvpS+t80= Date: Mon, 30 May 2022 21:37:19 +0200 From: Greg KH To: Ard Biesheuvel Cc: Russell King , Sasha Levin , Linux Kernel Mailing List , "# 3.4.x" , Russell King , Linus Walleij , Nicolas Pitre , Keith Packard , Arnd Bergmann , Linux ARM Subject: Re: [PATCH AUTOSEL 5.18 147/159] ARM: 9201/1: spectre-bhb: rely on linker to emit cross-section literal loads Message-ID: References: <20220530132425.1929512-1-sashal@kernel.org> <20220530132425.1929512-147-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 30, 2022 at 05:56:09PM +0200, Ard Biesheuvel wrote: > On Mon, 30 May 2022 at 17:25, Greg KH wrote: > > > > On Mon, May 30, 2022 at 03:32:47PM +0200, Ard Biesheuvel wrote: > > > AUTONAK > > > > > > As discussed before, please disregard all patches authored by me when > > > running the bot. > > > > Ok, but why wasn't this spectre-bhb commit asked to be backported to > > stable in the first place? > > Because it doesn't belong in -stable. Hence the lack of cc:stable or > fixes: tags. > > > Do older kernels not need these types of > > fixes? > > > > This commit was part of a series of six, two of which were bug fixes > and had fixes: tags. They do not have cc:stable tags because the > 'fixed' patches had not been backported yet when they were sent out. > > So those are clear candidates for -stable, and as far as I can tell, > they have already been backported. Great, thanks for verifying. > This patch does not fix a bug. It makes the asm code more resilient to > potential bugs introduced inadvertently by future changes, which will > be harder to detect now that we have three different versions of the > exception vector table. (Any given system will only exercise one of > the three, depending on whether and which Spectre-BHB workaround it > requires) Ok, that's good to know, it was not obvious from the changelog text that this wasn't doing anything but a cleanup. > I build and boot test my patches carefully, and so I consciously > decided that the regression risk of backporting this patch outweighs > the benefits. This is why I did not add a cc:stable or fixes: tag. If > a tag existed that said 'do not backport this unless explicitly > requested', I would have added it. > > I would expect anyone that proposes this patch for -stable to be as > diligent in ensuring that the patch is safe for backporting, which > includes building the code with older GCC versions that those stable > kernels still support, and boot testing the result on actual hardware. > > If this is part of the AUTOSEL workflow, then I stand corrected. But > even then, this does not mean that the patch *belongs* in -stable. As > you know, I enjoy throwing stable-kernel-rules.rst in your face, and I > am pretty sure that using a bot to find patches that apply cleanly and > happen not to cause build breakage is not covered by the criteria > defined by that document by any stretch of the imagination. > > On top of that, I feel that 'saving' precious stable maintainer's time > by using a bot to offload this burden to the community uninvited is > really not ok. We work very hard to keep highly heterogeneous > architectures such as ARM working across all supported platforms, and > this is work enough as it is without all the bogus patches that > AUTOSEL digs up without *any* justification beyond 'hey, it applies!' If you want to keep arm-core stuff out of the AUTOSEL process, because you all do a good job of marking stuff already properly, that's fine, Sasha can easily do that, just let us know. thanks, greg k-h