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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 D47E6C43460 for ; Thu, 15 Apr 2021 22:17:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6CC8661139 for ; Thu, 15 Apr 2021 22:17:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6CC8661139 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id DC0148D000E; Thu, 15 Apr 2021 18:17:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D4B8D8D000C; Thu, 15 Apr 2021 18:17:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AB1D98D000E; Thu, 15 Apr 2021 18:17:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0195.hostedemail.com [216.40.44.195]) by kanga.kvack.org (Postfix) with ESMTP id 7EC2F8D0003 for ; Thu, 15 Apr 2021 18:17:51 -0400 (EDT) Received: from smtpin36.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 3C4891838E528 for ; Thu, 15 Apr 2021 22:17:51 +0000 (UTC) X-FDA: 78036014742.36.31AA041 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by imf02.hostedemail.com (Postfix) with ESMTP id 2A88940002DD for ; Thu, 15 Apr 2021 22:17:32 +0000 (UTC) IronPort-SDR: Dh+nI5fekfPpAW0U5o9mP5M4CSjtOHjIvr9dt2nzJz5dYILYQ2mx96rE1VbEe4MGGNO9CJlho4 +EgOa02D8cpw== X-IronPort-AV: E=McAfee;i="6200,9189,9955"; a="215468367" X-IronPort-AV: E=Sophos;i="5.82,225,1613462400"; d="scan'208";a="215468367" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2021 15:17:48 -0700 IronPort-SDR: GR2QIhXtAvLyyLDhJK7j/d1IHPtTBJxYtrFbk4Gc6jPbT3ADRPjO7uHL3C1wy5sZxn3kgxLsz5 h6u9BSRD23NA== X-IronPort-AV: E=Sophos;i="5.82,225,1613462400"; d="scan'208";a="399720965" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2021 15:17:45 -0700 From: Yu-cheng Yu To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang Cc: Yu-cheng Yu Subject: [PATCH v25 2/9] x86/cet/ibt: Add user-mode Indirect Branch Tracking support Date: Thu, 15 Apr 2021 15:17:27 -0700 Message-Id: <20210415221734.32628-3-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20210415221734.32628-1-yu-cheng.yu@intel.com> References: <20210415221734.32628-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 2A88940002DD X-Stat-Signature: jds1xychktheiu1bq9tbtkub19e9zefw Received-SPF: none (intel.com>: No applicable sender policy available) receiver=imf02; identity=mailfrom; envelope-from=""; helo=mga01.intel.com; client-ip=192.55.52.88 X-HE-DKIM-Result: none/none X-HE-Tag: 1618525052-316797 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Introduce user-mode Indirect Branch Tracking (IBT) support. Add routines for the setup/disable of IBT. Signed-off-by: Yu-cheng Yu Cc: Kees Cook --- v24: - Move IBT routines to a separate ibt.c, update related areas accordingly= . arch/x86/include/asm/cet.h | 9 ++++++ arch/x86/kernel/Makefile | 1 + arch/x86/kernel/ibt.c | 57 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 67 insertions(+) create mode 100644 arch/x86/kernel/ibt.c diff --git a/arch/x86/include/asm/cet.h b/arch/x86/include/asm/cet.h index 662335ceb57f..17afcc9ea4d1 100644 --- a/arch/x86/include/asm/cet.h +++ b/arch/x86/include/asm/cet.h @@ -15,6 +15,7 @@ struct cet_status { unsigned long shstk_base; unsigned long shstk_size; unsigned int locked:1; + unsigned int ibt_enabled:1; }; =20 #ifdef CONFIG_X86_SHADOW_STACK @@ -41,6 +42,14 @@ static inline int shstk_check_rstor_token(bool ia32, u= nsigned long token_addr, unsigned long *new_ssp) { return 0; } #endif =20 +#ifdef CONFIG_X86_IBT +int ibt_setup(void); +void ibt_disable(void); +#else +static inline int ibt_setup(void) { return 0; } +static inline void ibt_disable(void) {} +#endif + #ifdef CONFIG_X86_SHADOW_STACK int prctl_cet(int option, u64 arg2); #else diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index eb13d578ad36..e10e007c1d80 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -151,6 +151,7 @@ obj-$(CONFIG_UNWINDER_GUESS) +=3D unwind_guess.o =20 obj-$(CONFIG_AMD_MEM_ENCRYPT) +=3D sev-es.o obj-$(CONFIG_X86_SHADOW_STACK) +=3D shstk.o cet_prctl.o +obj-$(CONFIG_X86_IBT) +=3D ibt.o =20 ### # 64 bit specific files diff --git a/arch/x86/kernel/ibt.c b/arch/x86/kernel/ibt.c new file mode 100644 index 000000000000..d2cef1a0345b --- /dev/null +++ b/arch/x86/kernel/ibt.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ibt.c - Intel Indirect Branch Tracking support + * + * Copyright (c) 2021, Intel Corporation. + * Yu-cheng Yu + */ + +#include +#include +#include +#include +#include +#include + +static void start_update_msrs(void) +{ + fpregs_lock(); + if (test_thread_flag(TIF_NEED_FPU_LOAD)) + __fpregs_load_activate(); +} + +static void end_update_msrs(void) +{ + fpregs_unlock(); +} + +int ibt_setup(void) +{ + u64 msr_val; + + if (!cpu_feature_enabled(X86_FEATURE_IBT)) + return -EOPNOTSUPP; + + start_update_msrs(); + rdmsrl(MSR_IA32_U_CET, msr_val); + msr_val |=3D (CET_ENDBR_EN | CET_NO_TRACK_EN); + wrmsrl(MSR_IA32_U_CET, msr_val); + end_update_msrs(); + current->thread.cet.ibt_enabled =3D 1; + return 0; +} + +void ibt_disable(void) +{ + u64 msr_val; + + if (!cpu_feature_enabled(X86_FEATURE_IBT)) + return; + + start_update_msrs(); + rdmsrl(MSR_IA32_U_CET, msr_val); + msr_val &=3D ~CET_ENDBR_EN; + wrmsrl(MSR_IA32_U_CET, msr_val); + end_update_msrs(); + current->thread.cet.ibt_enabled =3D 0; +} --=20 2.21.0