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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 D8846C64EB1 for ; Thu, 6 Dec 2018 23:44:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A9DCB20868 for ; Thu, 6 Dec 2018 23:44:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A9DCB20868 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 S1726478AbeLFXow (ORCPT ); Thu, 6 Dec 2018 18:44:52 -0500 Received: from foss.arm.com ([217.140.101.70]:35938 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbeLFXog (ORCPT ); Thu, 6 Dec 2018 18:44:36 -0500 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 AAB03168F; Thu, 6 Dec 2018 15:44:35 -0800 (PST) Received: from beelzebub.austin.arm.com (beelzebub.austin.arm.com [10.118.12.119]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2970A3F5AF; Thu, 6 Dec 2018 15:44:35 -0800 (PST) From: Jeremy Linton To: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will.deacon@arm.com, marc.zyngier@arm.com, suzuki.poulose@arm.com, dave.martin@arm.com, shankerd@codeaurora.org, mark.rutland@arm.com, linux-kernel@vger.kernel.org, ykaukab@suse.de, Jeremy Linton Subject: [PATCH 5/6] arm64: add sysfs vulnerability show for speculative store bypass Date: Thu, 6 Dec 2018 17:44:07 -0600 Message-Id: <20181206234408.1287689-6-jeremy.linton@arm.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20181206234408.1287689-1-jeremy.linton@arm.com> References: <20181206234408.1287689-1-jeremy.linton@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mian Yousaf Kaukab Return status based no ssbd_state and the arm64 SSBS feature. Return string "Unknown" in case CONFIG_ARM64_SSBD is disabled or arch workaround2 is not available in the firmware. Signed-off-by: Mian Yousaf Kaukab [Added SSBS logic] Signed-off-by: Jeremy Linton --- arch/arm64/kernel/cpu_errata.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 6505c93d507e..8aeb5ca38db8 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -423,6 +423,7 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry, ssbd_state = ARM64_SSBD_UNKNOWN; return false; + /* machines with mixed mitigation requirements must not return this */ case SMCCC_RET_NOT_REQUIRED: pr_info_once("%s mitigation not required\n", entry->desc); ssbd_state = ARM64_SSBD_MITIGATED; @@ -828,4 +829,31 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, } } +ssize_t cpu_show_spec_store_bypass(struct device *dev, + struct device_attribute *attr, char *buf) +{ + /* + * Two assumptions: First, get_ssbd_state() reflects the worse case + * for hetrogenous machines, and that if SSBS is supported its + * supported by all cores. + */ + switch (arm64_get_ssbd_state()) { + case ARM64_SSBD_MITIGATED: + return sprintf(buf, "Not affected\n"); + + case ARM64_SSBD_KERNEL: + case ARM64_SSBD_FORCE_ENABLE: + if (cpus_have_cap(ARM64_SSBS)) + return sprintf(buf, "Not affected\n"); + return sprintf(buf, + "Mitigation: Speculative Store Bypass disabled\n"); + + case ARM64_SSBD_FORCE_DISABLE: + return sprintf(buf, "Vulnerable\n"); + + default: /* ARM64_SSBD_UNKNOWN*/ + return sprintf(buf, "Unknown\n"); + } +} + #endif -- 2.17.2