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[23.128.96.18]) by mx.google.com with ESMTP id zp8si9299817ejb.255.2020.07.14.00.06.39; Tue, 14 Jul 2020 00:07:01 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726823AbgGNHEJ (ORCPT + 99 others); Tue, 14 Jul 2020 03:04:09 -0400 Received: from mga07.intel.com ([134.134.136.100]:36396 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725997AbgGNHEG (ORCPT ); Tue, 14 Jul 2020 03:04:06 -0400 IronPort-SDR: a1A9+X8wakkUx+Uj/w3EH88u4fGVLiosXj+N0BEwmO6/F13EZJPPwBXJ64DoTLqpfpVOHhDcWB zLpSTV3u183w== X-IronPort-AV: E=McAfee;i="6000,8403,9681"; a="213635611" X-IronPort-AV: E=Sophos;i="5.75,350,1589266800"; d="scan'208";a="213635611" 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; 14 Jul 2020 00:04:04 -0700 IronPort-SDR: nY/DFM9nVSCaOf42CJfiKh58xiTvUpfFPmJqpldQG8mdSpoKtENIWvEW6a2fSkGue2L/MLfD8V mS8Mw6tqq+8g== X-IronPort-AV: E=Sophos;i="5.75,350,1589266800"; d="scan'208";a="485774305" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jul 2020 00:04:03 -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: [RFC PATCH 02/15] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support Date: Tue, 14 Jul 2020 00:02:07 -0700 Message-Id: <20200714070220.3500839-3-ira.weiny@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200714070220.3500839-1-ira.weiny@intel.com> References: <20200714070220.3500839-1-ira.weiny@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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; +} -- 2.25.1