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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 C8766C4360C for ; Thu, 10 Oct 2019 12:46:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A4F3420673 for ; Thu, 10 Oct 2019 12:46:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733191AbfJJMqY (ORCPT ); Thu, 10 Oct 2019 08:46:24 -0400 Received: from foss.arm.com ([217.140.110.172]:58600 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733051AbfJJMqX (ORCPT ); Thu, 10 Oct 2019 08:46:23 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6795128; Thu, 10 Oct 2019 05:46:23 -0700 (PDT) Received: from dawn-kernel.cambridge.arm.com (unknown [10.1.197.116]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 936CF3F68E; Thu, 10 Oct 2019 05:46:22 -0700 (PDT) Subject: Re: [PATCH] arm64: cpufeature: Fix truncating a feature value To: Greg KH Cc: stable@vger.kernel.org, mark.rutland@arm.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org References: <20191010110856.4376-1-suzuki.poulose@arm.com> <20191010122922.GA720144@kroah.com> From: Suzuki K Poulose Message-ID: <295cfb9e-ac7b-73e7-bc80-8b9150f4a626@arm.com> Date: Thu, 10 Oct 2019 13:46:21 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 In-Reply-To: <20191010122922.GA720144@kroah.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On 10/10/2019 13:29, Greg KH wrote: > On Thu, Oct 10, 2019 at 12:12:01PM +0100, Suzuki K Poulose wrote: >> All, >> >> On 10/10/2019 12:08, Suzuki K Poulose wrote: >>> A signed feature value is truncated to turn to an unsigned value >>> causing bad state in the system wide infrastructure. This affects >>> the discovery of FP/ASIMD support on arm64. Fix this by making sure >>> we cast it properly. >>> >>> Fixes: 4f0a606bce5ec ("arm64: cpufeature: Track unsigned fields") >>> Cc: stable@vger.kernel.org # v4.4 >> >> Please note that this patch is only applicable for stable 4.4 tree. >> I should have removed the Fixes tag. > > Why is it only for 4.4? That needs to be documented really really This was fixed later in v4.6 onwards with commit 28c5dcb22f90113dea ("arm64: Rename cpuid_feature field extract routines") rather inadvertently. > really well in the changelog as to why this is a one-off patch, and why > we can't just take the relevant patches that are in Linus's tree > instead. > > Please fix up and resend. I can resend the patch with the above information included if you like. Cheers Suzuki