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=-12.7 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 62861C388F7 for ; Tue, 10 Nov 2020 16:25:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 011B320797 for ; Tue, 10 Nov 2020 16:25:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 011B320797 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 EB8F76B0070; Tue, 10 Nov 2020 11:25:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id DECDC6B0073; Tue, 10 Nov 2020 11:25:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C3F0C6B0072; Tue, 10 Nov 2020 11:25:07 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0157.hostedemail.com [216.40.44.157]) by kanga.kvack.org (Postfix) with ESMTP id 8EAF96B0071 for ; Tue, 10 Nov 2020 11:25:07 -0500 (EST) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 126261EE6 for ; Tue, 10 Nov 2020 16:25:07 +0000 (UTC) X-FDA: 77469033054.29.vest54_181679e272f6 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin29.hostedemail.com (Postfix) with ESMTP id 8E29218086CBA for ; Tue, 10 Nov 2020 16:25:06 +0000 (UTC) X-HE-Tag: vest54_181679e272f6 X-Filterd-Recvd-Size: 6899 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Tue, 10 Nov 2020 16:25:05 +0000 (UTC) IronPort-SDR: JVNnt0Pjz185gcWK/w8dUcuTr7glT0NK9Be+nRcs02il/KhsHG1wqtRDxfDNUPfOSXdxJSalx9 nE2q9JfMztBA== X-IronPort-AV: E=McAfee;i="6000,8403,9801"; a="170160141" X-IronPort-AV: E=Sophos;i="5.77,466,1596524400"; d="scan'208";a="170160141" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Nov 2020 08:25:03 -0800 IronPort-SDR: 8hgy2zFq9onRjh7g758jB74HvoHVkLx01eYQqxR7t+8c+cFHTnNUjJcWrg6QUnqmj2H39xLTpa zTD1oIqDRbGg== X-IronPort-AV: E=Sophos;i="5.77,466,1596524400"; d="scan'208";a="308469034" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Nov 2020 08:25:02 -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 v15 2/7] x86/cet/ibt: User-mode Indirect Branch Tracking support Date: Tue, 10 Nov 2020 08:24:43 -0800 Message-Id: <20201110162448.9846-3-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20201110162448.9846-1-yu-cheng.yu@intel.com> References: <20201110162448.9846-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 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. Update setup routines to include IBT. Signed-off-by: Yu-cheng Yu --- 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 ++++++++++++ 4 files changed, 60 insertions(+), 1 deletion(-) 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; }; =20 #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 6a9fb7f9bc01..e634a03fee14 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -68,6 +68,12 @@ #define DISABLE_SHSTK (1 << (X86_FEATURE_SHSTK & 31)) #endif =20 +#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 */ @@ -90,7 +96,7 @@ #define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_= UMIP| \ DISABLE_ENQCMD|DISABLE_SHSTK) #define DISABLED_MASK17 0 -#define DISABLED_MASK18 0 +#define DISABLED_MASK18 (DISABLE_IBT) #define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS !=3D 19) =20 #endif /* _ASM_X86_DISABLED_FEATURES_H */ diff --git a/arch/x86/kernel/cet.c b/arch/x86/kernel/cet.c index d57f3a433af9..1dcd16aa4f90 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) =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_SHSTK_EN; + wrmsrl(MSR_IA32_U_CET, msr_val); + end_update_msrs(); + current->thread.cet.ibt_enabled =3D 0; +} diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 3d38ae02d9d3..496d25e1c0a1 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -537,6 +537,23 @@ static __init int setup_disable_shstk(char *s) __setup("no_user_shstk", setup_disable_shstk); #endif =20 +#ifdef CONFIG_X86_BRANCH_TRACKING_USER +static __init int setup_disable_ibt(char *s) +{ + /* require an exact match without trailing characters */ + if (s[0] !=3D '\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 --=20 2.21.0