From patchwork Wed Feb 10 18:02:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu-cheng Yu X-Patchwork-Id: 12081561 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 4EAEDC4332D for ; Wed, 10 Feb 2021 18:03:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0479E64E6F for ; Wed, 10 Feb 2021 18:03:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0479E64E6F 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 A390B6B0073; Wed, 10 Feb 2021 13:03:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9C01C6B0074; Wed, 10 Feb 2021 13:03:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 85FFB6B007B; Wed, 10 Feb 2021 13:03:07 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0174.hostedemail.com [216.40.44.174]) by kanga.kvack.org (Postfix) with ESMTP id 521666B0074 for ; Wed, 10 Feb 2021 13:03:07 -0500 (EST) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 1ABB52C04 for ; Wed, 10 Feb 2021 18:03:07 +0000 (UTC) X-FDA: 77803129614.30.A83506B Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by imf12.hostedemail.com (Postfix) with ESMTP id 6F18413A for ; Wed, 10 Feb 2021 18:03:05 +0000 (UTC) IronPort-SDR: 4AyDr88P+t75T0VUNLfXiSTzY02x6+WnJ0Ggnkr8Z/rbOREaz0c148XCNgkyORmNp5MVAqYRDS RknIRY9zlcIA== X-IronPort-AV: E=McAfee;i="6000,8403,9891"; a="201237624" X-IronPort-AV: E=Sophos;i="5.81,168,1610438400"; d="scan'208";a="201237624" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2021 10:03:01 -0800 IronPort-SDR: x8F14DCv6Vjk1zonHii9kmNVYysgasjfthK/AFU0/LVXbvw8AAMTThFyblkrvkUabiIit4yzgk ri2HYUCm51Ag== X-IronPort-AV: E=Sophos;i="5.81,168,1610438400"; d="scan'208";a="380239204" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2021 10:02:56 -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 , Cc: Yu-cheng Yu Subject: [PATCH v20 2/7] x86/cet/ibt: User-mode Indirect Branch Tracking support Date: Wed, 10 Feb 2021 10:02:40 -0800 Message-Id: <20210210180245.13770-3-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20210210180245.13770-1-yu-cheng.yu@intel.com> References: <20210210180245.13770-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 X-Stat-Signature: 6iribjup3ek3711ncrtj6qsmr1d45d4t X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 6F18413A Received-SPF: none (intel.com>: No applicable sender policy available) receiver=imf12; identity=mailfrom; envelope-from=""; helo=mga01.intel.com; client-ip=192.55.52.88 X-HE-DKIM-Result: none/none X-HE-Tag: 1612980185-860625 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 16870e5bc8eb..3a1cba579cb2 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; }; #ifdef CONFIG_X86_CET @@ -26,6 +27,8 @@ 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 114f067eeb90..164139e23fef 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 @@ -341,3 +343,34 @@ int cet_setup_signal(bool ia32, unsigned long rstor_addr, struct sc_ext *sc_ext) 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 |= (CET_ENDBR_EN | CET_NO_TRACK_EN); + wrmsrl(MSR_IA32_U_CET, msr_val); + end_update_msrs(); + current->thread.cet.ibt_enabled = 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 &= ~CET_ENDBR_EN; + wrmsrl(MSR_IA32_U_CET, msr_val); + end_update_msrs(); + current->thread.cet.ibt_enabled = 0; +}