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_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham 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 C6FD1C67790 for ; Wed, 25 Jul 2018 08:56:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E66720882 for ; Wed, 25 Jul 2018 08:56:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E66720882 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728659AbeGYKGv (ORCPT ); Wed, 25 Jul 2018 06:06:51 -0400 Received: from foss.arm.com ([217.140.101.70]:34226 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728553AbeGYKGu (ORCPT ); Wed, 25 Jul 2018 06:06:50 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6B0EB80D; Wed, 25 Jul 2018 01:56:08 -0700 (PDT) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E670D3F237; Wed, 25 Jul 2018 01:56:06 -0700 (PDT) Date: Wed, 25 Jul 2018 09:56:04 +0100 From: Dave Martin To: Suzuki K Poulose Cc: Dirk Mueller , linux-arm-kernel@lists.infradead.org, Marc Zyngier , Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, Alex Graf Subject: Re: [PATCH] arm64: Check for errata before evaluating cpu features Message-ID: <20180725085604.GB4240@e103592.cambridge.arm.com> References: <20180725083504.25836-1-dmueller@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 25, 2018 at 09:51:53AM +0100, Suzuki K Poulose wrote: > On 07/25/2018 09:35 AM, Dirk Mueller wrote: > >Since commit d3aec8a28be3b8 ("arm64: capabilities: Restrict KPTI > >detection to boot-time CPUs") we rely on errata flags being already > >populated during feature enumeration. The order of errata and > >features was flipped as part of commit ed478b3f9e4a ("arm64: > >capabilities: Group handling of features and errata workarounds"). > > > >Return to the orginal order of errata and feature evaluation to > >ensure errata flags are present during feature evaluation. > > > >Fixes: d3aec8a28be3b8 ("arm64: capabilities: Restrict KPTI > >detection to boot-time CPUs") > >CC: Suzuki K Poulose > >CC: Marc Zyngier > >Signed-off-by: Dirk Mueller > > It would be good to add "Fixes: ed478b3f9e4a" (instead), just to make > sure this gets fixed everywhere the original problem appears. > > >--- > > arch/arm64/kernel/cpufeature.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > >diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > >index f24892a40d2c..c6d80743f4ed 100644 > >--- a/arch/arm64/kernel/cpufeature.c > >+++ b/arch/arm64/kernel/cpufeature.c > >@@ -1351,9 +1351,9 @@ static void __update_cpu_capabilities(const struct arm64_cpu_capabilities *caps, > > static void update_cpu_capabilities(u16 scope_mask) > > { > >- __update_cpu_capabilities(arm64_features, scope_mask, "detected:"); > > __update_cpu_capabilities(arm64_errata, scope_mask, > > "enabling workaround for"); > >+ __update_cpu_capabilities(arm64_features, scope_mask, "detected:"); > > } > > static int __enable_cpu_capability(void *arg) > >@@ -1408,8 +1408,8 @@ __enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps, > > static void __init enable_cpu_capabilities(u16 scope_mask) > > { > >- __enable_cpu_capabilities(arm64_features, scope_mask); > > __enable_cpu_capabilities(arm64_errata, scope_mask); > >+ __enable_cpu_capabilities(arm64_features, scope_mask); I forget why these were originally reordered in ed478b3f9e4a. Was there any real reason for it? I also notice in that commit that after the detection pass, we set things up (in update_cpu_capabilities(), enable_cpu_capabilities()) in the order errata, features. Does this matter for anything? Cheers ---Dave > > Reviewed-by: Suzuki K Poulose > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel