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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 981CAC43142 for ; Thu, 21 Jun 2018 21:18:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 582F921A17 for ; Thu, 21 Jun 2018 21:18:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 582F921A17 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933563AbeFUVSd (ORCPT ); Thu, 21 Jun 2018 17:18:33 -0400 Received: from mga14.intel.com ([192.55.52.115]:27244 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754278AbeFUVSE (ORCPT ); Thu, 21 Jun 2018 17:18:04 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Jun 2018 14:18:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,253,1526367600"; d="scan'208";a="48912128" Received: from hanvin-mobl2.amr.corp.intel.com ([10.254.42.214]) by fmsmga007.fm.intel.com with ESMTP; 21 Jun 2018 14:18:02 -0700 From: "H. Peter Anvin, Intel" To: Linux Kernel Mailing List Cc: "H. Peter Anvin" , "H . Peter Anvin" , Ingo Molnar , Thomas Gleixner , Andy Lutomirski , "Chang S . Bae" , "Markus T . Metzger" Subject: [PATCH v3 5/7] x86/segment: add #define for the last user-visible GDT slot Date: Thu, 21 Jun 2018 14:17:52 -0700 Message-Id: <20180621211754.12757-6-h.peter.anvin@intel.com> X-Mailer: git-send-email 2.14.4 In-Reply-To: <20180621211754.12757-1-h.peter.anvin@intel.com> References: <20180621211754.12757-1-h.peter.anvin@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "H. Peter Anvin" We don't want to advertise to user space how many slots the kernel GDT has, but user space can trivially find out what the last user-accessible GDT slot is. Add a #define for that so we can use that in sizing a regset. Signed-off-by: H. Peter Anvin (Intel) Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Andy Lutomirski Cc: Chang S. Bae Cc: Markus T. Metzger --- arch/x86/include/asm/segment.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index e293c122d0d5..5eb809eec048 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -115,6 +115,11 @@ */ #define GDT_ENTRIES 32 +/* + * Last user-visible GDT slot + */ +#define GDT_LAST_USER GDT_ENTRY_DEFAULT_USER_DS + /* * Segment selector values corresponding to the above entries: */ @@ -194,6 +199,11 @@ */ #define GDT_ENTRIES 16 +/* + * Last user-visible GDT slot + */ +#define GDT_LAST_USER GDT_ENTRY_PER_CPU + /* * Segment selector values corresponding to the above entries: * -- 2.14.4