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 198FDC25B07 for ; Tue, 9 Aug 2022 18:12:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245432AbiHISM3 (ORCPT ); Tue, 9 Aug 2022 14:12:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345792AbiHISLp (ORCPT ); Tue, 9 Aug 2022 14:11:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 434672B1A1; Tue, 9 Aug 2022 11:04:51 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 7706961070; Tue, 9 Aug 2022 18:04:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE977C433D6; Tue, 9 Aug 2022 18:04:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660068289; bh=S2xxbuptJ7V+bMWXdehtQv+Fi2QhUDp4XHIgVKjwTfM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0VLQxqus1+xsRqbvBsMZdCcgE7DdY0MfB9ildAqe1u2t02MT39/eP8Lj0zBARpdfL xpDxAlF0rYiX7OqjRunfdrCoNV3hzizIzy2wGMivvQzeqMOYCQ3azBqVHsxssGX6cS d54PCbHwY/7bKjiu5TNH+kJ3ncC36JHFIdbeur+c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ben Hutchings , Borislav Petkov Subject: [PATCH 5.15 01/30] x86/speculation: Make all RETbleed mitigations 64-bit only Date: Tue, 9 Aug 2022 20:00:26 +0200 Message-Id: <20220809175514.322531397@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220809175514.276643253@linuxfoundation.org> References: <20220809175514.276643253@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore 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: Ben Hutchings commit b648ab487f31bc4c38941bc770ea97fe394304bb upstream. The mitigations for RETBleed are currently ineffective on x86_32 since entry_32.S does not use the required macros. However, for an x86_32 target, the kconfig symbols for them are still enabled by default and /sys/devices/system/cpu/vulnerabilities/retbleed will wrongly report that mitigations are in place. Make all of these symbols depend on X86_64, and only enable RETHUNK by default on X86_64. Fixes: f43b9876e857 ("x86/retbleed: Add fine grained Kconfig knobs") Signed-off-by: Ben Hutchings Signed-off-by: Borislav Petkov Cc: Link: https://lore.kernel.org/r/YtwSR3NNsWp1ohfV@decadent.org.uk [bwh: Backported to 5.10/5.15/5.18: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- arch/x86/Kconfig | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2427,7 +2427,7 @@ config RETPOLINE config RETHUNK bool "Enable return-thunks" depends on RETPOLINE && CC_HAS_RETURN_THUNK - default y + default y if X86_64 help Compile the kernel with the return-thunks compiler option to guard against kernel-to-user data leaks by avoiding return speculation. @@ -2436,21 +2436,21 @@ config RETHUNK config CPU_UNRET_ENTRY bool "Enable UNRET on kernel entry" - depends on CPU_SUP_AMD && RETHUNK + depends on CPU_SUP_AMD && RETHUNK && X86_64 default y help Compile the kernel with support for the retbleed=unret mitigation. config CPU_IBPB_ENTRY bool "Enable IBPB on kernel entry" - depends on CPU_SUP_AMD + depends on CPU_SUP_AMD && X86_64 default y help Compile the kernel with support for the retbleed=ibpb mitigation. config CPU_IBRS_ENTRY bool "Enable IBRS on kernel entry" - depends on CPU_SUP_INTEL + depends on CPU_SUP_INTEL && X86_64 default y help Compile the kernel with support for the spectre_v2=ibrs mitigation.