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=-1.0 required=3.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 55BEFC282CE for ; Wed, 22 May 2019 15:39:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2918920881 for ; Wed, 22 May 2019 15:39:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729388AbfEVPjw (ORCPT ); Wed, 22 May 2019 11:39:52 -0400 Received: from ns.iliad.fr ([212.27.33.1]:56780 "EHLO ns.iliad.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728466AbfEVPjw (ORCPT ); Wed, 22 May 2019 11:39:52 -0400 Received: from ns.iliad.fr (localhost [127.0.0.1]) by ns.iliad.fr (Postfix) with ESMTP id 06FE020609; Wed, 22 May 2019 17:39:51 +0200 (CEST) Received: from [192.168.108.49] (freebox.vlq16.iliad.fr [213.36.7.13]) by ns.iliad.fr (Postfix) with ESMTP id E3BAF20072; Wed, 22 May 2019 17:39:50 +0200 (CEST) Subject: Re: [PATCH v2 7/9] arm64: dts: qcom: msm8998: Add PSCI cpuidle low power states To: Marc Zyngier , MSM , Linux ARM Cc: Amit Kucheria , Bjorn Andersson , Daniel Lezcano , Niklas Cassel , Jeffrey Hugo , Sibi Sankar , Mark Rutland , Lorenzo Pieralisi , Robin Murphy , Sudeep Holla References: <49cf5d94beb9af9ef4e78d4c52f3b0ad20b7c63f.1558430617.git.amit.kucheria@linaro.org> <2f8db49a-759c-d560-70c1-d041beeea914@arm.com> From: Marc Gonzalez Message-ID: Date: Wed, 22 May 2019 17:39:50 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <2f8db49a-759c-d560-70c1-d041beeea914@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV using ClamSMTP ; ns.iliad.fr ; Wed May 22 17:39:51 2019 +0200 (CEST) Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 22/05/2019 11:35, Marc Zyngier wrote: > On 22/05/2019 10:17, Marc Gonzalez wrote: > >> The following dmesg log caught my eye, and might be relevant: >> >> ARM_SMCCC_ARCH_WORKAROUND_1 missing from firmware >> >> Is that bad, doctor? I don't think it would explain the crash though... > > It doesn't explain it. > > It is bad though: your vendor doesn't tell the kernel about the HW being > free of Spectre-v2, and doesn't provide a mitigation either. Hopefully, > this is a responsible vendor that will provide you with a firmware > update that fixes it. # cd /sys/devices/system/cpu/vulnerabilities/ # grep "" * l1tf:Not affected mds:Not affected meltdown:Mitigation: PTI spec_store_bypass:Vulnerable spectre_v1:Mitigation: __user pointer sanitization spectre_v2:Vulnerable OK, so there are apparently two unmitigated vulns, spec_store_bypass and spectre_v2. These vulns need to be mitigated in FW because otherwise some secure property of the secure OS could be violated? Or because disabling the faulty optimization requires secure privileges? Some documentation, for my own reference: https://elixir.bootlin.com/linux/latest/source/Documentation/ABI/testing/sysfs-devices-system-cpu https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability Regards.