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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 7DD52C4741F for ; Fri, 25 Sep 2020 14:58:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 462F2221EC for ; Fri, 25 Sep 2020 14:58:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729200AbgIYO6V (ORCPT ); Fri, 25 Sep 2020 10:58:21 -0400 Received: from mga07.intel.com ([134.134.136.100]:47916 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729123AbgIYO6O (ORCPT ); Fri, 25 Sep 2020 10:58:14 -0400 IronPort-SDR: MrXJ7xGY8+7ECUF0FjZFGr/TEL082SvcJdOiJZUsErwWsUlW6lZ+3F5783LT4MXxClGJUtoOVP 62hwNZ7FctYQ== X-IronPort-AV: E=McAfee;i="6000,8403,9755"; a="225704482" X-IronPort-AV: E=Sophos;i="5.77,302,1596524400"; d="scan'208";a="225704482" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2020 07:58:14 -0700 IronPort-SDR: dfbruIsKSdLkIzJd2sNrV54uUbD038MUuLRSp0Cl1fv5L55B1OtnAuoPQEM4ZkLFx7Fcd8WGtj 9ug7hOcugZ5g== X-IronPort-AV: E=Sophos;i="5.77,302,1596524400"; d="scan'208";a="512916962" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2020 07:58:13 -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 Cc: Yu-cheng Yu Subject: [PATCH v13 2/8] x86/cet/ibt: User-mode Indirect Branch Tracking support Date: Fri, 25 Sep 2020 07:57:58 -0700 Message-Id: <20200925145804.5821-3-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20200925145804.5821-1-yu-cheng.yu@intel.com> References: <20200925145804.5821-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Introduce user-mode Indirect Branch Tracking (IBT) support. Update setup routines to include IBT. Signed-off-by: Yu-cheng Yu --- v10: - Change no_cet_ibt to no_user_ibt. v9: - Change cpu_feature_enabled() to static_cpu_has(). v2: - Change noibt to no_cet_ibt. arch/x86/include/asm/cet.h | 3 ++ arch/x86/include/asm/disabled-features.h | 8 ++++- arch/x86/kernel/cet.c | 33 +++++++++++++++++++ arch/x86/kernel/cpu/common.c | 17 ++++++++++ .../arch/x86/include/asm/disabled-features.h | 8 ++++- 5 files changed, 67 insertions(+), 2 deletions(-) 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/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index edac76ed75e7..e7096a1e2698 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -62,6 +62,12 @@ #define DISABLE_SHSTK (1<<(X86_FEATURE_SHSTK & 31)) #endif +#ifdef CONFIG_X86_BRANCH_TRACKING_USER +#define DISABLE_IBT 0 +#else +#define DISABLE_IBT (1<<(X86_FEATURE_IBT & 31)) +#endif + /* * Make sure to add features to the correct mask */ @@ -83,7 +89,7 @@ #define DISABLED_MASK15 0 #define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_UMIP|DISABLE_SHSTK) #define DISABLED_MASK17 0 -#define DISABLED_MASK18 0 +#define DISABLED_MASK18 (DISABLE_IBT) #define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19) #endif /* _ASM_X86_DISABLED_FEATURES_H */ diff --git a/arch/x86/kernel/cet.c b/arch/x86/kernel/cet.c index b285c726bb88..e95fadb264f7 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_SHSTK_EN; + wrmsrl(MSR_IA32_U_CET, msr_val); + end_update_msrs(); + current->thread.cet.ibt_enabled = 0; +} diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 084480f975aa..909b4160a2d2 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -536,6 +536,23 @@ static __init int setup_disable_shstk(char *s) __setup("no_user_shstk", setup_disable_shstk); #endif +#ifdef CONFIG_X86_BRANCH_TRACKING_USER +static __init int setup_disable_ibt(char *s) +{ + /* require an exact match without trailing characters */ + if (s[0] != '\0') + return 0; + + if (!boot_cpu_has(X86_FEATURE_IBT)) + return 1; + + setup_clear_cpu_cap(X86_FEATURE_IBT); + pr_info("x86: 'no_user_ibt' specified, disabling user Branch Tracking\n"); + return 1; +} +__setup("no_user_ibt", setup_disable_ibt); +#endif + /* * Some CPU features depend on higher CPUID levels, which may not always * be available due to CPUID level capping or broken virtualization diff --git a/tools/arch/x86/include/asm/disabled-features.h b/tools/arch/x86/include/asm/disabled-features.h index edac76ed75e7..e7096a1e2698 100644 --- a/tools/arch/x86/include/asm/disabled-features.h +++ b/tools/arch/x86/include/asm/disabled-features.h @@ -62,6 +62,12 @@ #define DISABLE_SHSTK (1<<(X86_FEATURE_SHSTK & 31)) #endif +#ifdef CONFIG_X86_BRANCH_TRACKING_USER +#define DISABLE_IBT 0 +#else +#define DISABLE_IBT (1<<(X86_FEATURE_IBT & 31)) +#endif + /* * Make sure to add features to the correct mask */ @@ -83,7 +89,7 @@ #define DISABLED_MASK15 0 #define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_UMIP|DISABLE_SHSTK) #define DISABLED_MASK17 0 -#define DISABLED_MASK18 0 +#define DISABLED_MASK18 (DISABLE_IBT) #define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19) #endif /* _ASM_X86_DISABLED_FEATURES_H */ -- 2.21.0