From patchwork Fri Oct 9 19:42:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 285942 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=unavailable 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 069DBC4363D for ; Fri, 9 Oct 2020 19:43:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D309322282 for ; Fri, 9 Oct 2020 19:43:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390767AbgJITnQ (ORCPT ); Fri, 9 Oct 2020 15:43:16 -0400 Received: from mga07.intel.com ([134.134.136.100]:55979 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390752AbgJITnN (ORCPT ); Fri, 9 Oct 2020 15:43:13 -0400 IronPort-SDR: xvNZtwplYA0Lr6RImAn6BUpfnfS/aO4ACP9ti3g91ZVfo0y/+wZEBWP/jtSG7GQv0i2/8YJGQZ iUqChcSoHkSQ== X-IronPort-AV: E=McAfee;i="6000,8403,9769"; a="229714253" X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="229714253" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2020 12:43:12 -0700 IronPort-SDR: qfQGwj/Ls/ugPHwCmAAiBeOeJJx3gtIcomNrAcTjfMS2lWba5WxQkMOPVaTlBjfwy9WZfzuusi pcPsJ+HG3BGA== X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="343970170" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2020 12:43:11 -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 , 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 V3 2/9] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support Date: Fri, 9 Oct 2020 12:42:51 -0700 Message-Id: <20201009194258.3207172-3-ira.weiny@intel.com> X-Mailer: git-send-email 2.28.0.rc0.12.gb6a658bd00c9 In-Reply-To: <20201009194258.3207172-1-ira.weiny@intel.com> References: <20201009194258.3207172-1-ira.weiny@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Fenghua Yu Define a helper, update_pkey_val(), 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 Signed-off-by: Peter Zijlstra --- arch/x86/include/asm/pkeys.h | 2 ++ arch/x86/kernel/fpu/xstate.c | 22 ++++------------------ arch/x86/mm/pkeys.c | 21 +++++++++++++++++++++ 3 files changed, 27 insertions(+), 18 deletions(-) diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h index f9feba80894b..4526245b03e5 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 update_pkey_val(u32 pk_reg, int pkey, unsigned int flags); + #endif /*_ASM_X86_PKEYS_H */ diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index b55cf3acd82a..725f10670d0a 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -990,9 +990,7 @@ 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 pkru; /* * This check implies XSAVE support. OSPKE only gets @@ -1008,21 +1006,9 @@ 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); - - /* Write old part along with new part: */ - write_pkru(old_pkru | new_pkru_bits); + pkru = read_pkru(); + pkru = update_pkey_val(pkru, pkey, init_val); + write_pkru(pkru); return 0; } diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c index f5efb4007e74..3cf8f775f36d 100644 --- a/arch/x86/mm/pkeys.c +++ b/arch/x86/mm/pkeys.c @@ -208,3 +208,24 @@ static __init int setup_init_pkru(char *opt) return 1; } __setup("init_pkru=", setup_init_pkru); + +/* + * Update the pk_reg value and return it. + * + * Kernel users use the same flags as user space: + * PKEY_DISABLE_ACCESS + * PKEY_DISABLE_WRITE + */ +u32 update_pkey_val(u32 pk_reg, int pkey, unsigned int flags) +{ + int pkey_shift = pkey * PKR_BITS_PER_PKEY; + + pk_reg &= ~(((1 << PKR_BITS_PER_PKEY) - 1) << pkey_shift); + + if (flags & PKEY_DISABLE_ACCESS) + pk_reg |= PKR_AD_BIT << pkey_shift; + if (flags & PKEY_DISABLE_WRITE) + pk_reg |= PKR_WD_BIT << pkey_shift; + + return pk_reg; +}