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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 E6EA9C10F14 for ; Thu, 10 Oct 2019 08:49:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ACC4F2064A for ; Thu, 10 Oct 2019 08:49:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697343; bh=FwfZPGAk5k2aXhVoQMbOGLDLpIQ+GKcriv79nfKQ7mo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=L6Igf7h1E7EdmSg6GcrjVVY4gUjKjHeo+S6cnPfACXoUouQllOciPIcdocNgjF9Kr rtHs8PdH35T38sKufd1wIEQhjosF+P/pLMCv4Hf7F+ivEsXaonpRfBnWY50DfyKbxw LShynQcpkbxnF1hj7xLZ5Ao5EHf6HqnIeIHdz3Lc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389741AbfJJItC (ORCPT ); Thu, 10 Oct 2019 04:49:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:55350 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389731AbfJJIs7 (ORCPT ); Thu, 10 Oct 2019 04:48:59 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1908D218AC; Thu, 10 Oct 2019 08:48:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697337; bh=FwfZPGAk5k2aXhVoQMbOGLDLpIQ+GKcriv79nfKQ7mo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g2irBCh9gSyiqTT7y7h49ILL6lbUX5su3w+GZGTjrmhYwXz++wsx/LNhfY46eyo7P fCjwmbRf4GgZVrWKzCzjrcQQkuZlPNMVvBY4sWZSHaBhrJXf2ZL7MrbRTyaLF3P3ze 8uYxZXsmL+34cOhujsPzMkqtWJET/7ssjOMyEdMQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Josh Poimboeuf , Will Deacon , Ard Biesheuvel Subject: [PATCH 4.19 105/114] arm64/speculation: Support mitigations= cmdline option Date: Thu, 10 Oct 2019 10:36:52 +0200 Message-Id: <20191010083613.783241526@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191010083544.711104709@linuxfoundation.org> References: <20191010083544.711104709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Josh Poimboeuf commit a111b7c0f20e13b54df2fa959b3dc0bdf1925ae6 upstream. Configure arm64 runtime CPU speculation bug mitigations in accordance with the 'mitigations=' cmdline option. This affects Meltdown, Spectre v2, and Speculative Store Bypass. The default behavior is unchanged. Signed-off-by: Josh Poimboeuf [will: reorder checks so KASLR implies KPTI and SSBS is affected by cmdline] Signed-off-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman --- Documentation/admin-guide/kernel-parameters.txt | 8 +++++--- arch/arm64/kernel/cpu_errata.c | 6 +++++- arch/arm64/kernel/cpufeature.c | 8 +++++++- 3 files changed, 17 insertions(+), 5 deletions(-) --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2503,8 +2503,8 @@ http://repo.or.cz/w/linux-2.6/mini2440.git mitigations= - [X86,PPC,S390] Control optional mitigations for CPU - vulnerabilities. This is a set of curated, + [X86,PPC,S390,ARM64] Control optional mitigations for + CPU vulnerabilities. This is a set of curated, arch-independent options, each of which is an aggregation of existing arch-specific options. @@ -2513,12 +2513,14 @@ improves system performance, but it may also expose users to several CPU vulnerabilities. Equivalent to: nopti [X86,PPC] + kpti=0 [ARM64] nospectre_v1 [PPC] nobp=0 [S390] nospectre_v1 [X86] - nospectre_v2 [X86,PPC,S390] + nospectre_v2 [X86,PPC,S390,ARM64] spectre_v2_user=off [X86] spec_store_bypass_disable=off [X86,PPC] + ssbd=force-off [ARM64] l1tf=off [X86] mds=off [X86] --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -355,6 +356,9 @@ static bool has_ssbd_mitigation(const st WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible()); + if (cpu_mitigations_off()) + ssbd_state = ARM64_SSBD_FORCE_DISABLE; + /* delay setting __ssb_safe until we get a firmware response */ if (is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list)) this_cpu_safe = true; @@ -600,7 +604,7 @@ check_branch_predictor(const struct arm6 } /* forced off */ - if (__nospectre_v2) { + if (__nospectre_v2 || cpu_mitigations_off()) { pr_info_once("spectrev2 mitigation disabled by command line option\n"); __hardenbp_enab = false; return false; --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -907,7 +908,7 @@ static bool unmap_kernel_at_el0(const st MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), { /* sentinel */ } }; - char const *str = "command line option"; + char const *str = "kpti command line option"; bool meltdown_safe; meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list); @@ -937,6 +938,11 @@ static bool unmap_kernel_at_el0(const st } } + if (cpu_mitigations_off() && !__kpti_forced) { + str = "mitigations=off"; + __kpti_forced = -1; + } + if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) { pr_info_once("kernel page table isolation disabled by kernel configuration\n"); return false;