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=-16.7 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 B0161C433E0 for ; Wed, 17 Feb 2021 22:31:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 428F464EAD for ; Wed, 17 Feb 2021 22:31:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 428F464EAD 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 34B0E6B006E; Wed, 17 Feb 2021 17:31:50 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 31F5A6B0070; Wed, 17 Feb 2021 17:31:50 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 19F906B0071; Wed, 17 Feb 2021 17:31:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0095.hostedemail.com [216.40.44.95]) by kanga.kvack.org (Postfix) with ESMTP id D71B86B0070 for ; Wed, 17 Feb 2021 17:31:49 -0500 (EST) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 98681824999B for ; Wed, 17 Feb 2021 22:31:49 +0000 (UTC) X-FDA: 77829208338.26.B770291 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by imf18.hostedemail.com (Postfix) with ESMTP id 232242000D8E for ; Wed, 17 Feb 2021 22:31:48 +0000 (UTC) IronPort-SDR: G/j6CRNzcraQU5fuDL2l1FckpeL/4Mqr7YyXeJt3PSAtIJSw77cLkV7/7rN0bCBi6c1ifHaFGW cC4niHmVl38g== X-IronPort-AV: E=McAfee;i="6000,8403,9898"; a="179825706" X-IronPort-AV: E=Sophos;i="5.81,185,1610438400"; d="scan'208";a="179825706" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Feb 2021 14:31:47 -0800 IronPort-SDR: CiMXfXQDjg2TqojXiGIMyyop8Tb2u39CAw492hp9P0fszZsddVtFWGGnZprgOw0mplgZIx2PYZ 0m3EdXOuctGg== X-IronPort-AV: E=Sophos;i="5.81,185,1610438400"; d="scan'208";a="362200463" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Feb 2021 14:31:46 -0800 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 v21 2/7] x86/cet/ibt: User-mode Indirect Branch Tracking support Date: Wed, 17 Feb 2021 14:31:30 -0800 Message-Id: <20210217223135.16790-3-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20210217223135.16790-1-yu-cheng.yu@intel.com> References: <20210217223135.16790-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 X-Stat-Signature: rhhjear5g6kaj6x8ftxxdnbfkdiceyym X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 232242000D8E Received-SPF: none (intel.com>: No applicable sender policy available) receiver=imf18; identity=mailfrom; envelope-from=""; helo=mga11.intel.com; client-ip=192.55.52.93 X-HE-DKIM-Result: none/none X-HE-Tag: 1613601108-728149 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 Reviewed-by: Kees Cook --- arch/x86/include/asm/cet.h | 3 +++ arch/x86/kernel/cet.c | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/arch/x86/include/asm/cet.h b/arch/x86/include/asm/cet.h index c2437378f339..c20c2f671145 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_CET @@ -27,6 +28,8 @@ void cet_free_shstk(struct task_struct *p); int cet_verify_rstor_token(bool ia32, unsigned long ssp, unsigned long *= new_ssp); void cet_restore_signal(struct sc_ext *sc); int cet_setup_signal(bool ia32, unsigned long rstor, struct sc_ext *sc); +int cet_setup_ibt(void); +void cet_disable_ibt(void); #else static inline int prctl_cet(int option, u64 arg2) { return -EINVAL; } static inline int cet_setup_thread_shstk(struct task_struct *p, diff --git a/arch/x86/kernel/cet.c b/arch/x86/kernel/cet.c index 12738cdfb5f2..3361706ba950 100644 --- a/arch/x86/kernel/cet.c +++ b/arch/x86/kernel/cet.c @@ -13,6 +13,8 @@ #include #include #include +#include +#include #include #include #include @@ -346,3 +348,34 @@ int cet_setup_signal(bool ia32, unsigned long rstor_= addr, struct sc_ext *sc_ext) =20 return 0; } + +int cet_setup_ibt(void) +{ + u64 msr_val; + + if (!static_cpu_has(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 cet_disable_ibt(void) +{ + u64 msr_val; + + if (!static_cpu_has(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