From patchwork Thu Apr 4 16:44:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josh Poimboeuf X-Patchwork-Id: 10885959 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 7A16C17EE for ; Thu, 4 Apr 2019 16:46:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5EAA128AC6 for ; Thu, 4 Apr 2019 16:46:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5136228AD0; Thu, 4 Apr 2019 16:46:18 +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 D85CC28AC6 for ; Thu, 4 Apr 2019 16:46:17 +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=QfB1/U8/6Lf84sFfmxQWnbYF6HCXLF1uG2hiwcNwNOo=; b=tXsQz3KBV+yE3IDtb8J/Lylyp9 ZluhNfR+PugZIWgwLmPhYJplPEtSyBU5MIx2QOvEfAjGeqAUjwFZy8LCpTZNFC/rBh2bUJEgzJaoq jKBXHYfCw0wwTFYPqdXSCHR2WTUbw2F0aBJZfsrjKAAwzOiaae/2wgS/Pk0IQetu2SCePHU8fcIJL uL/gr6TPlm5BbkIp1LzXQUi29Wo/08ZvSgowNeoIU9GDMHoFtBoG9+siM249gvRtft74pPI5DPaUT aMZkvnfCRAU5ktzAsgzBrlUN4MJBBZEY0MpCzKz8enWLdWt3fW11/YN55FgsFYyVQRwGp38Ucyn1P BLT0t+RA==; 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 1hC5VG-0001gD-Rm; Thu, 04 Apr 2019 16:46:14 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hC5UR-0000gd-6a for linux-arm-kernel@lists.infradead.org; Thu, 04 Apr 2019 16:45:37 +0000 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 939ED30832C9; Thu, 4 Apr 2019 16:45:22 +0000 (UTC) Received: from treble.redhat.com (ovpn-125-158.rdu2.redhat.com [10.10.125.158]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7568C608EB; Thu, 4 Apr 2019 16:45:17 +0000 (UTC) From: Josh Poimboeuf To: linux-kernel@vger.kernel.org Subject: [PATCH RFC 5/5] arm64/speculation: Add support for 'cpu_spec_mitigations=' cmdline options Date: Thu, 4 Apr 2019 11:44:15 -0500 Message-Id: <5f70df57b19bbccc4a0d5d76134b4681c9a50b0b.1554396090.git.jpoimboe@redhat.com> In-Reply-To: References: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Thu, 04 Apr 2019 16:45:22 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190404_094523_811658_C2F9B7CF X-CRM114-Status: GOOD ( 15.86 ) 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: Peter Zijlstra , Benjamin Herrenschmidt , Heiko Carstens , Paul Mackerras , "H . Peter Anvin" , Ingo Molnar , Andrea Arcangeli , linux-s390@vger.kernel.org, Michael Ellerman , x86@kernel.org, Will Deacon , Linus Torvalds , Catalin Marinas , Waiman Long , linux-arch@vger.kernel.org, Jon Masters , Jiri Kosina , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Greg Kroah-Hartman , Tyler Hicks , Martin Schwidefsky , linuxppc-dev@lists.ozlabs.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 Configure arm64 runtime CPU speculation bug mitigations in accordance with the 'cpu_spec_mitigations=' cmdline options. This affects Meltdown and Speculative Store Bypass. The default behavior is unchanged. Signed-off-by: Josh Poimboeuf --- Documentation/admin-guide/kernel-parameters.txt | 2 ++ arch/arm64/kernel/cpu_errata.c | 4 ++++ arch/arm64/kernel/cpufeature.c | 6 ++++++ 3 files changed, 12 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index e838af96daa4..0b54385ee7a8 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2553,11 +2553,13 @@ off Disable all speculative CPU mitigations. Equivalent to: nopti [x86, powerpc] + kpti=0 [arm64] nospectre_v1 [powerpc] nospectre_v2 [x86, powerpc, s390] spectre_v2_user=off [x86] nobp=0 [s390] spec_store_bypass_disable=off [x86, powerpc] + ssbd=force-off [arm64] l1tf=off [x86] auto (default) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 9950bb0cbd52..db8d27e3fb1c 100644 --- 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 @@ -385,6 +386,9 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry, return false; } + if (cpu_spec_mitigations == CPU_SPEC_MITIGATIONS_OFF) + ssbd_state = ARM64_SSBD_FORCE_DISABLE; + switch (psci_ops.conduit) { case PSCI_CONDUIT_HVC: arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 4061de10cea6..4512b582d50f 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -978,6 +979,11 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, __kpti_forced = -1; } + if (cpu_spec_mitigations == CPU_SPEC_MITIGATIONS_OFF) { + str = "cpu_spec_mitigations=off"; + __kpti_forced = -1; + } + /* Forced? */ if (__kpti_forced) { pr_info_once("kernel page table isolation forced %s by %s\n",