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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8DBBC433EF for ; Sat, 23 Jul 2022 10:10:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238954AbiGWKKA (ORCPT ); Sat, 23 Jul 2022 06:10:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239069AbiGWKJQ (ORCPT ); Sat, 23 Jul 2022 06:09:16 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22CE23ED67; Sat, 23 Jul 2022 03:02:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E4064B82C1B; Sat, 23 Jul 2022 10:01:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 57DFDC341CE; Sat, 23 Jul 2022 10:01:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658570518; bh=p/gFMJFw+0KXPwGqJWjVQcM1S+G3M3UFlYzAwYKkkCQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C5qLNLiPdy8xSHewWmSzV6hgsN2EzsyhqOMyZp9lj2D2uYlDqTFJHbGz5mZzaSaxU HtXXXpHKhaB81kz8k5eh315f0kUtG1IBWv3mLMn6vxTfTSp8n4pYEkgOjIlEBj4M26 V35N2lq2v4t/FGfgb7uApDXTdhx8Oc+P9dohozGY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Josh Poimboeuf , "Peter Zijlstra (Intel)" , Borislav Petkov , Thadeu Lima de Souza Cascardo , Ben Hutchings Subject: [PATCH 5.10 114/148] x86/speculation: Fix SPEC_CTRL write on SMT state change Date: Sat, 23 Jul 2022 11:55:26 +0200 Message-Id: <20220723095256.314818325@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220723095224.302504400@linuxfoundation.org> References: <20220723095224.302504400@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Josh Poimboeuf commit 56aa4d221f1ee2c3a49b45b800778ec6e0ab73c5 upstream. If the SMT state changes, SSBD might get accidentally disabled. Fix that. Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/bugs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1414,7 +1414,8 @@ static void __init spectre_v2_select_mit static void update_stibp_msr(void * __unused) { - write_spec_ctrl_current(x86_spec_ctrl_base, true); + u64 val = spec_ctrl_current() | (x86_spec_ctrl_base & SPEC_CTRL_STIBP); + write_spec_ctrl_current(val, true); } /* Update x86_spec_ctrl_base in case SMT state changed. */