From patchwork Fri Jan 25 18:07:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeremy Linton X-Patchwork-Id: 156621 Delivered-To: patch@linaro.org Received: by 2002:a02:48:0:0:0:0:0 with SMTP id 69csp652266jaa; Fri, 25 Jan 2019 10:07:28 -0800 (PST) X-Google-Smtp-Source: ALg8bN6PerQckVFHqd/5/nNaN05lziKMtR57O2SIRuf5CufJsUv0snaGMV/YEK4D9V2Ala3FQWLX X-Received: by 2002:a62:4c5:: with SMTP id 188mr12089096pfe.130.1548439648201; Fri, 25 Jan 2019 10:07:28 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1548439648; cv=none; d=google.com; s=arc-20160816; b=ea3RXEawLndXLKObZWqxgrKViKbbSVPf1PxqryUXsGaWtV5odBpXpmVyCkL6X+QLhc 1s82EBBzAv3PMGwqVZeCXg4pdwwsZS55NvwSwfTP0ntfkWwJD4XVSrt9M8UPSC/pZOD/ Ovq4w75/3fRxOx+nIPMEeMqA+qFuttff3TtTx+a+1aLPUkZCFIBPSzCHYAJPmH42BElJ rCZ81zIyRwCYFmcBpsHYPILjsgvy72SyDUyqEW3nayMQ95Shp2yYMDWg8HwO9SGyGh92 pGE4eQjPH0Vc7SwoHy+b+Pa7KWLGVCoumpGFsYbGRr3Ael9LLDPFIOqgxcWpR9uY5mG9 FGpg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from; bh=Q05QjCs9q4IVn0C4iHVSIYFCudby+tF5/zrLwC9OmNo=; b=KN8+SJ87JkoFcLdkibAEmkKRwy46Capru05+uSVsDTXnvw5IDlFMXhi+HaOh2MJumA IVv8pa6eCFwyv7zRjpXwF0IjMkIUOmFZj9YD5Wn+GATOlnMmWWgUdHpNvOjjzfLT/Z82 MmI6W6dRC5s4vntVI68Ow76mGFFuaNP+8OJbtyTM14Bb1RVzLNr2JmSVZs4XYYUn5gz8 OdL46sT+CTtN1LJZE38fmj28IptrZY3Ep4tCPq4DRc1Zk36ZymIG84EhSYaWp0XAI+IB hzWYaB/kiuuu3bJP4Wqq8fnFFQfbfpR+jfgJ/vTe5fcIK4EsF33ipSDlBQ1v1mOgSZ49 /JUw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id b7si26435128plk.206.2019.01.25.10.07.27; Fri, 25 Jan 2019 10:07:28 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729066AbfAYSHZ (ORCPT + 31 others); Fri, 25 Jan 2019 13:07:25 -0500 Received: from foss.arm.com ([217.140.101.70]:51770 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729135AbfAYSHX (ORCPT ); Fri, 25 Jan 2019 13:07:23 -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 3220F1650; Fri, 25 Jan 2019 10:07:23 -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 78E013F5AF; Fri, 25 Jan 2019 10:07:22 -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, linux-kernel@vger.kernel.org, ykaukab@suse.de, julien.thierry@arm.com, mlangsdo@redhat.com, steven.price@arm.com, stefan.wahren@i2se.com, Jeremy Linton , Jonathan Corbet , linux-doc@vger.kernel.org Subject: [PATCH v4 02/12] arm64: Provide a command line to disable spectre_v2 mitigation Date: Fri, 25 Jan 2019 12:07:01 -0600 Message-Id: <20190125180711.1970973-3-jeremy.linton@arm.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190125180711.1970973-1-jeremy.linton@arm.com> References: <20190125180711.1970973-1-jeremy.linton@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are various reasons, including bencmarking, to disable spectrev2 mitigation on a machine. Provide a command-line to do so. Signed-off-by: Jeremy Linton Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org --- Documentation/admin-guide/kernel-parameters.txt | 8 ++++---- arch/arm64/kernel/cpu_errata.c | 11 +++++++++++ 2 files changed, 15 insertions(+), 4 deletions(-) -- 2.17.2 Reviewed-by: Andre Przywara diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9475f02c79da..2ae77979488e 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2849,10 +2849,10 @@ check bypass). With this option data leaks are possible in the system. - nospectre_v2 [X86,PPC_FSL_BOOK3E] Disable all mitigations for the Spectre variant 2 - (indirect branch prediction) vulnerability. System may - allow data leaks with this option, which is equivalent - to spectre_v2=off. + nospectre_v2 [X86,PPC_FSL_BOOK3E,ARM64] Disable all mitigations for + the Spectre variant 2 (indirect branch prediction) + vulnerability. System may allow data leaks with this + option. nospec_store_bypass_disable [HW] Disable all mitigations for the Speculative Store Bypass vulnerability diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 9950bb0cbd52..9a7b5fca51a0 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -220,6 +220,14 @@ static void qcom_link_stack_sanitization(void) : "=&r" (tmp)); } +static bool __nospectre_v2; +static int __init parse_nospectre_v2(char *str) +{ + __nospectre_v2 = true; + return 0; +} +early_param("nospectre_v2", parse_nospectre_v2); + static void enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) { @@ -231,6 +239,9 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) if (!entry->matches(entry, SCOPE_LOCAL_CPU)) return; + if (__nospectre_v2) + return; + if (psci_ops.smccc_version == SMCCC_VERSION_1_0) return;