From patchwork Fri Jul 17 07:20:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 11669313 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A67B214E3 for ; Fri, 17 Jul 2020 07:22:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 929BA2083E for ; Fri, 17 Jul 2020 07:22:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728336AbgGQHWK (ORCPT ); Fri, 17 Jul 2020 03:22:10 -0400 Received: from mga12.intel.com ([192.55.52.136]:48157 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728014AbgGQHVF (ORCPT ); Fri, 17 Jul 2020 03:21:05 -0400 IronPort-SDR: euGBuBzK4eGB63eW/2jMZlalPhL7JtIT/9aB72lXmqcgG4zvZRNnbulICoxnrpytsAz1ZP09zc AGoXh651vtqA== X-IronPort-AV: E=McAfee;i="6000,8403,9684"; a="129111928" X-IronPort-AV: E=Sophos;i="5.75,362,1589266800"; d="scan'208";a="129111928" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2020 00:21:03 -0700 IronPort-SDR: 8i/TZE8qfmw3EhMgZhG/RVSFnd+u3sPC5jkD2v98KRJWRdSZ/qmdi+GKnE2LirhYp+nvpHB/Ax DUj5ubNB3hxw== X-IronPort-AV: E=Sophos;i="5.75,362,1589266800"; d="scan'208";a="300484565" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2020 00:21:01 -0700 From: ira.weiny@intel.com To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Peter Zijlstra Cc: Fenghua Yu , Ira Weiny , x86@kernel.org, Dave Hansen , Dan Williams , Vishal Verma , Andrew Morton , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH RFC V2 02/17] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support Date: Fri, 17 Jul 2020 00:20:41 -0700 Message-Id: <20200717072056.73134-3-ira.weiny@intel.com> X-Mailer: git-send-email 2.28.0.rc0.12.gb6a658bd00c9 In-Reply-To: <20200717072056.73134-1-ira.weiny@intel.com> References: <20200717072056.73134-1-ira.weiny@intel.com> MIME-Version: 1.0 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Fenghua Yu Define a helper, get_new_pkr(), which will be used to support both Protection Key User (PKU) and the new Protection Key for Supervisor (PKS) in subsequent patches. Co-developed-by: Ira Weiny Signed-off-by: Ira Weiny Signed-off-by: Fenghua Yu --- arch/x86/include/asm/pkeys.h | 2 ++ arch/x86/kernel/fpu/xstate.c | 17 +++-------------- arch/x86/mm/pkeys.c | 28 ++++++++++++++++++++++++++++ 3 files changed, 33 insertions(+), 14 deletions(-) diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h index be8b3e448f76..34cef29fed20 100644 --- a/arch/x86/include/asm/pkeys.h +++ b/arch/x86/include/asm/pkeys.h @@ -136,4 +136,6 @@ static inline int vma_pkey(struct vm_area_struct *vma) return (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT; } +u32 get_new_pkr(u32 old_pkr, int pkey, unsigned long init_val); + #endif /*_ASM_X86_PKEYS_H */ diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index fc1ec2986e03..1def71dc8105 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -954,9 +954,7 @@ const void *get_xsave_field_ptr(int xfeature_nr) int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, unsigned long init_val) { - u32 old_pkru; - int pkey_shift = (pkey * PKR_BITS_PER_PKEY); - u32 new_pkru_bits = 0; + u32 old_pkru, new_pkru; /* * This check implies XSAVE support. OSPKE only gets @@ -972,21 +970,12 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, */ WARN_ON_ONCE(pkey >= arch_max_pkey()); - /* Set the bits we need in PKRU: */ - if (init_val & PKEY_DISABLE_ACCESS) - new_pkru_bits |= PKR_AD_BIT; - if (init_val & PKEY_DISABLE_WRITE) - new_pkru_bits |= PKR_WD_BIT; - - /* Shift the bits in to the correct place in PKRU for pkey: */ - new_pkru_bits <<= pkey_shift; - /* Get old PKRU and mask off any old bits in place: */ old_pkru = read_pkru(); - old_pkru &= ~((PKR_AD_BIT|PKR_WD_BIT) << pkey_shift); + new_pkru = get_new_pkr(old_pkru, pkey, init_val); /* Write old part along with new part: */ - write_pkru(old_pkru | new_pkru_bits); + write_pkru(new_pkru); return 0; } diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c index f5efb4007e74..a5c680d32930 100644 --- a/arch/x86/mm/pkeys.c +++ b/arch/x86/mm/pkeys.c @@ -208,3 +208,31 @@ static __init int setup_init_pkru(char *opt) return 1; } __setup("init_pkru=", setup_init_pkru); + +/* + * Get a new pkey register value from the user values specified. + * + * Kernel users use the same flags as user space: + * PKEY_DISABLE_ACCESS + * PKEY_DISABLE_WRITE + */ +u32 get_new_pkr(u32 old_pkr, int pkey, unsigned long init_val) +{ + int pkey_shift = (pkey * PKR_BITS_PER_PKEY); + u32 new_pkr_bits = 0; + + /* Set the bits we need in the register: */ + if (init_val & PKEY_DISABLE_ACCESS) + new_pkr_bits |= PKR_AD_BIT; + if (init_val & PKEY_DISABLE_WRITE) + new_pkr_bits |= PKR_WD_BIT; + + /* Shift the bits in to the correct place: */ + new_pkr_bits <<= pkey_shift; + + /* Mask off any old bits in place: */ + old_pkr &= ~((PKR_AD_BIT | PKR_WD_BIT) << pkey_shift); + + /* Return the old part along with the new part: */ + return old_pkr | new_pkr_bits; +}