From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933087AbcA2SYg (ORCPT ); Fri, 29 Jan 2016 13:24:36 -0500 Received: from mga09.intel.com ([134.134.136.24]:18247 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932897AbcA2SRE (ORCPT ); Fri, 29 Jan 2016 13:17:04 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,365,1449561600"; d="scan'208";a="643614140" Subject: [PATCH 14/31] x86, pkeys: add functions to fetch PKRU To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, x86@kernel.org, torvalds@linux-foundation.org, Dave Hansen , dave.hansen@linux.intel.com From: Dave Hansen Date: Fri, 29 Jan 2016 10:17:02 -0800 References: <20160129181642.98E7D468@viggo.jf.intel.com> In-Reply-To: <20160129181642.98E7D468@viggo.jf.intel.com> Message-Id: <20160129181702.70523C9C@viggo.jf.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Hansen This adds the raw instruction to access PKRU as well as some accessor functions that correctly handle when the CPU does not support the instruction. We don't use it here, but we will use read_pkru() in the next patch. Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner --- b/arch/x86/include/asm/pgtable.h | 8 ++++++++ b/arch/x86/include/asm/special_insns.h | 22 ++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff -puN arch/x86/include/asm/pgtable.h~pkeys-10-kernel-pkru-instructions arch/x86/include/asm/pgtable.h --- a/arch/x86/include/asm/pgtable.h~pkeys-10-kernel-pkru-instructions 2016-01-28 15:52:22.425498599 -0800 +++ b/arch/x86/include/asm/pgtable.h 2016-01-28 15:52:22.430498828 -0800 @@ -99,6 +99,14 @@ static inline int pte_dirty(pte_t pte) return pte_flags(pte) & _PAGE_DIRTY; } + +static inline u32 read_pkru(void) +{ + if (boot_cpu_has(X86_FEATURE_OSPKE)) + return __read_pkru(); + return 0; +} + static inline int pte_young(pte_t pte) { return pte_flags(pte) & _PAGE_ACCESSED; diff -puN arch/x86/include/asm/special_insns.h~pkeys-10-kernel-pkru-instructions arch/x86/include/asm/special_insns.h --- a/arch/x86/include/asm/special_insns.h~pkeys-10-kernel-pkru-instructions 2016-01-28 15:52:22.427498691 -0800 +++ b/arch/x86/include/asm/special_insns.h 2016-01-28 15:52:22.431498874 -0800 @@ -98,6 +98,28 @@ static inline void native_write_cr8(unsi } #endif +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +static inline u32 __read_pkru(void) +{ + u32 ecx = 0; + u32 edx, pkru; + + /* + * "rdpkru" instruction. Places PKRU contents in to EAX, + * clears EDX and requires that ecx=0. + */ + asm volatile(".byte 0x0f,0x01,0xee\n\t" + : "=a" (pkru), "=d" (edx) + : "c" (ecx)); + return pkru; +} +#else +static inline u32 __read_pkru(void) +{ + return 0; +} +#endif + static inline void native_wbinvd(void) { asm volatile("wbinvd": : :"memory"); _ From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f179.google.com (mail-pf0-f179.google.com [209.85.192.179]) by kanga.kvack.org (Postfix) with ESMTP id 5B855828DF for ; Fri, 29 Jan 2016 13:17:19 -0500 (EST) Received: by mail-pf0-f179.google.com with SMTP id n128so45582738pfn.3 for ; Fri, 29 Jan 2016 10:17:19 -0800 (PST) Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTP id we3si3530534pab.52.2016.01.29.10.17.02 for ; Fri, 29 Jan 2016 10:17:03 -0800 (PST) Subject: [PATCH 14/31] x86, pkeys: add functions to fetch PKRU From: Dave Hansen Date: Fri, 29 Jan 2016 10:17:02 -0800 References: <20160129181642.98E7D468@viggo.jf.intel.com> In-Reply-To: <20160129181642.98E7D468@viggo.jf.intel.com> Message-Id: <20160129181702.70523C9C@viggo.jf.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, x86@kernel.org, torvalds@linux-foundation.org, Dave Hansen , dave.hansen@linux.intel.com From: Dave Hansen This adds the raw instruction to access PKRU as well as some accessor functions that correctly handle when the CPU does not support the instruction. We don't use it here, but we will use read_pkru() in the next patch. Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner --- b/arch/x86/include/asm/pgtable.h | 8 ++++++++ b/arch/x86/include/asm/special_insns.h | 22 ++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff -puN arch/x86/include/asm/pgtable.h~pkeys-10-kernel-pkru-instructions arch/x86/include/asm/pgtable.h --- a/arch/x86/include/asm/pgtable.h~pkeys-10-kernel-pkru-instructions 2016-01-28 15:52:22.425498599 -0800 +++ b/arch/x86/include/asm/pgtable.h 2016-01-28 15:52:22.430498828 -0800 @@ -99,6 +99,14 @@ static inline int pte_dirty(pte_t pte) return pte_flags(pte) & _PAGE_DIRTY; } + +static inline u32 read_pkru(void) +{ + if (boot_cpu_has(X86_FEATURE_OSPKE)) + return __read_pkru(); + return 0; +} + static inline int pte_young(pte_t pte) { return pte_flags(pte) & _PAGE_ACCESSED; diff -puN arch/x86/include/asm/special_insns.h~pkeys-10-kernel-pkru-instructions arch/x86/include/asm/special_insns.h --- a/arch/x86/include/asm/special_insns.h~pkeys-10-kernel-pkru-instructions 2016-01-28 15:52:22.427498691 -0800 +++ b/arch/x86/include/asm/special_insns.h 2016-01-28 15:52:22.431498874 -0800 @@ -98,6 +98,28 @@ static inline void native_write_cr8(unsi } #endif +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +static inline u32 __read_pkru(void) +{ + u32 ecx = 0; + u32 edx, pkru; + + /* + * "rdpkru" instruction. Places PKRU contents in to EAX, + * clears EDX and requires that ecx=0. + */ + asm volatile(".byte 0x0f,0x01,0xee\n\t" + : "=a" (pkru), "=d" (edx) + : "c" (ecx)); + return pkru; +} +#else +static inline u32 __read_pkru(void) +{ + return 0; +} +#endif + static inline void native_wbinvd(void) { asm volatile("wbinvd": : :"memory"); _ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org