From patchwork Wed Jan 9 23:55:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeremy Linton X-Patchwork-Id: 10754997 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 51D0917D2 for ; Wed, 9 Jan 2019 23:57:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3EC3529289 for ; Wed, 9 Jan 2019 23:57:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2F12029307; Wed, 9 Jan 2019 23:57:13 +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 AEA6629289 for ; Wed, 9 Jan 2019 23:57:12 +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=twpVXofTowBjt90yl0f2dXkhAHKMJ+BYY3+SPKEzKqA=; b=N5Z7vtOcrenOutwesAms5bo//A Yord6jZl7g1aZLJageAMhOX3kpMC98ye3kmXxDRJG0WfIQ61oiUFeccO6fx4l8lKr/roWe/u0oGPv N8svd2hO5onoXuRztZdiEkywlkueEDpe6bWENCIsX0E5VcQh5R1e0zd8FoByfwFlt30PHrME4zYcG GvYfhjJ4y7UiLAyJoGmC1OteXAHoyWShWW8XJ6F+dq61MPw/tSeaKOUwwkGbtIB9MvlaRivnnn6+U 2ynZm6dc6ro4spad31ehs835Q38IyPkYtnyEp/flE30sULtPB1k98f8KS26G9n1JtiobQPR++4lw/ hi2kXu8w==; 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 1ghNif-0007BJ-RY; Wed, 09 Jan 2019 23:57:09 +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 1ghNhU-00060B-N8 for linux-arm-kernel@lists.infradead.org; Wed, 09 Jan 2019 23:56:03 +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 2F09BA78; Wed, 9 Jan 2019 15:55:56 -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 8795C3F5AF; Wed, 9 Jan 2019 15:55:55 -0800 (PST) From: Jeremy Linton To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 5/7] arm64: add sysfs vulnerability show for spectre v2 Date: Wed, 9 Jan 2019 17:55:42 -0600 Message-Id: <20190109235544.2992426-6-jeremy.linton@arm.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190109235544.2992426-1-jeremy.linton@arm.com> References: <20190109235544.2992426-1-jeremy.linton@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190109_155557_343846_D0B9D08C X-CRM114-Status: GOOD ( 14.64 ) 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: stefan.wahren@i2se.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 Add code to track whether all the cores in the machine are vulnerable, and whether all the vulnerable cores have been mitigated. Once we have that information we can add the sysfs stub and provide an accurate view of what is known about the machine. Signed-off-by: Jeremy Linton --- arch/arm64/kernel/cpu_errata.c | 61 +++++++++++++++++++++++++++++++--- 1 file changed, 56 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 8dde8c616b7e..ee286d606d9b 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -111,6 +111,11 @@ atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1); uint arm64_requested_vuln_attrs = VULN_SPECTREV1; +#if defined(CONFIG_HARDEN_BRANCH_PREDICTOR) || defined(CONFIG_GENERIC_CPU_VULNERABILITIES) +/* Track overall mitigation state. We are only mitigated if all cores are ok */ +static bool __hardenbp_enab = true; +#endif + #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR #include #include @@ -233,15 +238,19 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) if (!entry->matches(entry, SCOPE_LOCAL_CPU)) return; - if (psci_ops.smccc_version == SMCCC_VERSION_1_0) + if (psci_ops.smccc_version == SMCCC_VERSION_1_0) { + __hardenbp_enab = false; return; + } switch (psci_ops.conduit) { case PSCI_CONDUIT_HVC: arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); - if ((int)res.a0 < 0) + if ((int)res.a0 < 0) { + __hardenbp_enab = false; return; + } cb = call_hvc_arch_workaround_1; /* This is a guest, no need to patch KVM vectors */ smccc_start = NULL; @@ -251,14 +260,17 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) case PSCI_CONDUIT_SMC: arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); - if ((int)res.a0 < 0) + if ((int)res.a0 < 0) { + __hardenbp_enab = false; return; + } cb = call_smc_arch_workaround_1; smccc_start = __smccc_workaround_1_smc_start; smccc_end = __smccc_workaround_1_smc_end; break; default: + __hardenbp_enab = false; return; } @@ -509,7 +521,32 @@ cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused) .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \ CAP_MIDR_RANGE_LIST(midr_list) -#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR +#if defined(CONFIG_HARDEN_BRANCH_PREDICTOR) || \ + defined(CONFIG_GENERIC_CPU_VULNERABILITIES) + + +static bool __spectrev2_safe = true; + +/* + * Track overall bp hardening for all heterogeneous cores in the machine. + * We are only considered "safe" if all booted cores are known safe. + */ +static bool __maybe_unused +check_branch_predictor(const struct arm64_cpu_capabilities *entry, int scope) +{ + bool is_vul; + + WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible()); + + is_vul = is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list); + + if (is_vul) + __spectrev2_safe = false; + + arm64_requested_vuln_attrs |= VULN_SPECTREV2; + + return is_vul; +} /* * List of CPUs where we need to issue a psci call to @@ -707,7 +744,9 @@ const struct arm64_cpu_capabilities arm64_errata[] = { { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, .cpu_enable = enable_smccc_arch_workaround_1, - ERRATA_MIDR_RANGE_LIST(arm64_bp_harden_smccc_cpus), + .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, + .matches = check_branch_predictor, + .midr_range_list = arm64_bp_harden_smccc_cpus, }, #endif #ifdef CONFIG_HARDEN_EL2_VECTORS @@ -758,4 +797,16 @@ ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, return sprintf(buf, "Mitigation: __user pointer sanitization\n"); } +ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, + char *buf) +{ + if (__spectrev2_safe) + return sprintf(buf, "Not affected\n"); + + if (__hardenbp_enab) + return sprintf(buf, "Mitigation: Branch predictor hardening\n"); + + return sprintf(buf, "Vulnerable\n"); +} + #endif