From patchwork Thu Jan 3 00:49:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeremy Linton X-Patchwork-Id: 10746805 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9F4EC6C5 for ; Thu, 3 Jan 2019 00:51:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8BEC1283B1 for ; Thu, 3 Jan 2019 00:51:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7FF5828405; Thu, 3 Jan 2019 00:51:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 1CECC283B1 for ; Thu, 3 Jan 2019 00:51:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=SiF2osGhVPdgGhrO2it4J2wBw+/hcWQ+8R3PS05O3tM=; b=dfZbb9TLhouH+6HXKKAylne7fV 1qXMDh+NJutJozXHocVtkQatiRkwQGefdoLp2vph4qukBmN1te91S8eBcQUW6s4iFn2fDXXdC2Xqy 4Tw9tsWjpURVDGqDFM4BLXHWxsegkBVJT3vNknUophSjQijQ4cpglTBphwVj33tkfgBocoKEkscOG b11xA1GOEsgLq19XNKXXS6WL7pckapMdVR8JogNS6dswPE8YbPWcKcH1RWAD185hBI+JeFRaG+CQJ 2Xtdoa4KEDoTHhBneH8v33wwpNFbgo2vPgecNFKtEKFt2L4ll/S6cxV9o83cVcCNjo8735WEenl03 yE/WPmbg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gerDw-0003QE-GY; Thu, 03 Jan 2019 00:51:00 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gerCd-0000tg-9X for linux-arm-kernel@lists.infradead.org; Thu, 03 Jan 2019 00:49:46 +0000 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 17BFA1596; Wed, 2 Jan 2019 16:49:39 -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 415EF3F5AF; Wed, 2 Jan 2019 16:49:38 -0800 (PST) From: Jeremy Linton To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 6/7] arm64: add sysfs vulnerability show for speculative store bypass Date: Wed, 2 Jan 2019 18:49:20 -0600 Message-Id: <20190103004921.1928921-7-jeremy.linton@arm.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190103004921.1928921-1-jeremy.linton@arm.com> References: <20190103004921.1928921-1-jeremy.linton@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190102_164939_835869_0790103D X-CRM114-Status: GOOD ( 10.68 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, mlangsdo@redhat.com, suzuki.poulose@arm.com, marc.zyngier@arm.com, catalin.marinas@arm.com, julien.thierry@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, Jeremy Linton , steven.price@arm.com, ykaukab@suse.de, dave.martin@arm.com, shankerd@codeaurora.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Mian Yousaf Kaukab Return status based on 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 96a55accefa9..c962b5856c87 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -420,6 +420,7 @@ 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; @@ -810,4 +811,31 @@ 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