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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 A59ECC04E53 for ; Wed, 15 May 2019 12:04:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E40820657 for ; Wed, 15 May 2019 12:04:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557921886; bh=1O5XAIKcgkmvxRMEoezlXrFLzM3tRA3WT9bCo5hJLeY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=L3UVPQ9XZWeRyC/KAGnMfRantC68z4ZZHRAZGU+AT7G6XeNMjWBQmIj1Svh/ZHGS4 5WFiY25uBh4v+PV1zsHILjdrfDkevmEztJ8E9TaSn3S3+YEkY1ycGK23eD5G3/fXDe 3frH0rvbvHDW60EiIXdZ1/ofmJR4A7AJzeEuzXnY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729372AbfEOLL3 (ORCPT ); Wed, 15 May 2019 07:11:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:46012 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729164AbfEOLL0 (ORCPT ); Wed, 15 May 2019 07:11:26 -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 4D93221473; Wed, 15 May 2019 11:11:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557918684; bh=1O5XAIKcgkmvxRMEoezlXrFLzM3tRA3WT9bCo5hJLeY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dWTO+Z+XK7eGSZ9NNvYFBpfk7by+0bc1tpAaMvnSDcDJmqtxng6ICG7wDMZmLTaC3 5s5nbnWtxKCbZpjmhRXxwMqak1xnUlUBhbsa3KPJCoUHQ3SOtk0Jqkz+U3o4tMbt60 yK4mX/O7KcqTA4XKY4dDLu53DCmE654JQzulPiOU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Andy Lutomirski , Linus Torvalds , Jiri Kosina , Tom Lendacky , Josh Poimboeuf , Andrea Arcangeli , David Woodhouse , Tim Chen , Andi Kleen , Dave Hansen , Casey Schaufler , Asit Mallick , Arjan van de Ven , Jon Masters , Waiman Long , Dave Stewart , Kees Cook , Ben Hutchings Subject: [PATCH 4.4 226/266] x86/speculation: Provide IBPB always command line options Date: Wed, 15 May 2019 12:55:33 +0200 Message-Id: <20190515090730.644770059@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190515090722.696531131@linuxfoundation.org> References: <20190515090722.696531131@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Thomas Gleixner commit 55a974021ec952ee460dc31ca08722158639de72 upstream. Provide the possibility to enable IBPB always in combination with 'prctl' and 'seccomp'. Add the extra command line options and rework the IBPB selection to evaluate the command instead of the mode selected by the STIPB switch case. Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar Cc: Peter Zijlstra Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Jiri Kosina Cc: Tom Lendacky Cc: Josh Poimboeuf Cc: Andrea Arcangeli Cc: David Woodhouse Cc: Tim Chen Cc: Andi Kleen Cc: Dave Hansen Cc: Casey Schaufler Cc: Asit Mallick Cc: Arjan van de Ven Cc: Jon Masters Cc: Waiman Long Cc: Greg KH Cc: Dave Stewart Cc: Kees Cook Link: https://lkml.kernel.org/r/20181125185006.144047038@linutronix.de [bwh: Backported to 4.4: adjust filename] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- Documentation/kernel-parameters.txt | 12 ++++++++++++ arch/x86/kernel/cpu/bugs.c | 34 +++++++++++++++++++++++----------- 2 files changed, 35 insertions(+), 11 deletions(-) --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3651,11 +3651,23 @@ bytes respectively. Such letter suffixes per thread. The mitigation control state is inherited on fork. + prctl,ibpb + - Like "prctl" above, but only STIBP is + controlled per thread. IBPB is issued + always when switching between different user + space processes. + seccomp - Same as "prctl" above, but all seccomp threads will enable the mitigation unless they explicitly opt out. + seccomp,ibpb + - Like "seccomp" above, but only STIBP is + controlled per thread. IBPB is issued + always when switching between different + user space processes. + auto - Kernel selects the mitigation depending on the available CPU features and vulnerability. --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -245,7 +245,9 @@ enum spectre_v2_user_cmd { SPECTRE_V2_USER_CMD_AUTO, SPECTRE_V2_USER_CMD_FORCE, SPECTRE_V2_USER_CMD_PRCTL, + SPECTRE_V2_USER_CMD_PRCTL_IBPB, SPECTRE_V2_USER_CMD_SECCOMP, + SPECTRE_V2_USER_CMD_SECCOMP_IBPB, }; static const char * const spectre_v2_user_strings[] = { @@ -260,11 +262,13 @@ static const struct { enum spectre_v2_user_cmd cmd; bool secure; } v2_user_options[] __initdata = { - { "auto", SPECTRE_V2_USER_CMD_AUTO, false }, - { "off", SPECTRE_V2_USER_CMD_NONE, false }, - { "on", SPECTRE_V2_USER_CMD_FORCE, true }, - { "prctl", SPECTRE_V2_USER_CMD_PRCTL, false }, - { "seccomp", SPECTRE_V2_USER_CMD_SECCOMP, false }, + { "auto", SPECTRE_V2_USER_CMD_AUTO, false }, + { "off", SPECTRE_V2_USER_CMD_NONE, false }, + { "on", SPECTRE_V2_USER_CMD_FORCE, true }, + { "prctl", SPECTRE_V2_USER_CMD_PRCTL, false }, + { "prctl,ibpb", SPECTRE_V2_USER_CMD_PRCTL_IBPB, false }, + { "seccomp", SPECTRE_V2_USER_CMD_SECCOMP, false }, + { "seccomp,ibpb", SPECTRE_V2_USER_CMD_SECCOMP_IBPB, false }, }; static void __init spec_v2_user_print_cond(const char *reason, bool secure) @@ -310,6 +314,7 @@ spectre_v2_user_select_mitigation(enum s { enum spectre_v2_user_mitigation mode = SPECTRE_V2_USER_NONE; bool smt_possible = IS_ENABLED(CONFIG_SMP); + enum spectre_v2_user_cmd cmd; if (!boot_cpu_has(X86_FEATURE_IBPB) && !boot_cpu_has(X86_FEATURE_STIBP)) return; @@ -317,17 +322,20 @@ spectre_v2_user_select_mitigation(enum s if (!IS_ENABLED(CONFIG_SMP)) smt_possible = false; - switch (spectre_v2_parse_user_cmdline(v2_cmd)) { + cmd = spectre_v2_parse_user_cmdline(v2_cmd); + switch (cmd) { case SPECTRE_V2_USER_CMD_NONE: goto set_mode; case SPECTRE_V2_USER_CMD_FORCE: mode = SPECTRE_V2_USER_STRICT; break; case SPECTRE_V2_USER_CMD_PRCTL: + case SPECTRE_V2_USER_CMD_PRCTL_IBPB: mode = SPECTRE_V2_USER_PRCTL; break; case SPECTRE_V2_USER_CMD_AUTO: case SPECTRE_V2_USER_CMD_SECCOMP: + case SPECTRE_V2_USER_CMD_SECCOMP_IBPB: if (IS_ENABLED(CONFIG_SECCOMP)) mode = SPECTRE_V2_USER_SECCOMP; else @@ -339,12 +347,15 @@ spectre_v2_user_select_mitigation(enum s if (boot_cpu_has(X86_FEATURE_IBPB)) { setup_force_cpu_cap(X86_FEATURE_USE_IBPB); - switch (mode) { - case SPECTRE_V2_USER_STRICT: + switch (cmd) { + case SPECTRE_V2_USER_CMD_FORCE: + case SPECTRE_V2_USER_CMD_PRCTL_IBPB: + case SPECTRE_V2_USER_CMD_SECCOMP_IBPB: static_branch_enable(&switch_mm_always_ibpb); break; - case SPECTRE_V2_USER_PRCTL: - case SPECTRE_V2_USER_SECCOMP: + case SPECTRE_V2_USER_CMD_PRCTL: + case SPECTRE_V2_USER_CMD_AUTO: + case SPECTRE_V2_USER_CMD_SECCOMP: static_branch_enable(&switch_mm_cond_ibpb); break; default: @@ -352,7 +363,8 @@ spectre_v2_user_select_mitigation(enum s } pr_info("mitigation: Enabling %s Indirect Branch Prediction Barrier\n", - mode == SPECTRE_V2_USER_STRICT ? "always-on" : "conditional"); + static_key_enabled(&switch_mm_always_ibpb) ? + "always-on" : "conditional"); } /* If enhanced IBRS is enabled no STIPB required */