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 X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05E71C433FF for ; Wed, 7 Aug 2019 12:53:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC9B521E6A for ; Wed, 7 Aug 2019 12:53:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565182386; bh=y3/TCMmGeuWLU9RU7+PuunFVGK076zHVaDl8Kp8eU4M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=BmeYblCXDw+pP8BU5S8Z/wbXYORh5pC+evVVkIdjNWIjIGJDPtv7fy+gOYsKfc+l+ QONI8pzGURk974YRxH97ptvmTfdOwjl31aQzYuUTx2VGmQt7KsE35zRjxE9camXE9p 4ko565PX3odxQ8adm5feZA1UvW3vCcsom5EtxXU4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729712AbfHGMxG (ORCPT ); Wed, 7 Aug 2019 08:53:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:60036 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727213AbfHGMxG (ORCPT ); Wed, 7 Aug 2019 08:53:06 -0400 Received: from localhost (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D089521BE3; Wed, 7 Aug 2019 12:53:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565182385; bh=y3/TCMmGeuWLU9RU7+PuunFVGK076zHVaDl8Kp8eU4M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BWYuS3xxI0XQ7Mh+QBZE+7maNJirRkRjYcytJKFM6PAp2dmdwvtj2sShcwGeZ56fI NDFknUvl726uYDtEtIwftP1Zbjz/0y4qWoAMy4aQR2mSvOknpFRLpiczg9l7yt1Fuz XennZYxgQNNv+n3xdzwOCFyULKp+h5O3cVKdPf8w= Date: Wed, 7 Aug 2019 08:53:03 -0400 From: Sasha Levin To: Suzuki K Poulose Cc: will@kernel.org, gregkh@linuxfoundation.org, stable@vger.kernel.org Subject: Re: [PATCH 0/2] [Backport for 4.4.y stable] arm64 CTR_EL0 cpufeature fixes Message-ID: <20190807125303.GT17747@sasha-vm> References: <20190805171308.19249-1-will@kernel.org> <20190806212904.GL17747@sasha-vm> <20190807094919.qzkf2jj6m4qrecsl@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, Aug 07, 2019 at 11:59:41AM +0100, Suzuki K Poulose wrote: >Hi Will, > >On 07/08/2019 10:49, Will Deacon wrote: >>Hi Sasha, [+Suzuki] >> >>On Tue, Aug 06, 2019 at 05:29:04PM -0400, Sasha Levin wrote: >>>On Mon, Aug 05, 2019 at 06:13:06PM +0100, Will Deacon wrote: >>>>These two patches are backports for 4.4.y stable kernels after one of >>>>them failed to apply: >>>> >>>> https://lkml.kernel.org/r/156498316752100@kroah.com >>> >>>I took these 2, but note that they have two fixes that are not in 4.4: >>> >>>314d53d297980 arm64: Handle mismatched cache type >>>4c4a39dd5fe2d arm64: Fix mismatched cache line size detection >>> >>>Will you send a backport for them? >> >>4.4 doesn't handle mismatches for the cache type or the line sizes, and >>instead taints the kernel with a big splat at boot. If we wanted to >>backport this, we'd need to pick up more than just the above patches, since >>we don't have the means to emulate user cache maintenance operations either. >> >>Given that the vast majority of systems don't suffer from this problem, >>I'd be inclined not to try shoe-horning all of this into 4.4, where I think >>it's more likely introduce other issues. >> >>Suzuki, what do you think? > >I agree. It involves a lot of new code, with non-trivial backports. Okay, makes sense. Thanks for looking into it. -- Thanks, Sasha