Received: by 2002:ac0:a581:0:0:0:0:0 with SMTP id m1-v6csp81909imm; Thu, 21 Jun 2018 14:20:04 -0700 (PDT) X-Google-Smtp-Source: ADUXVKJyBtBgRLqIxnEJh9J6k4wfSATIvHcMTnxzoEgrppOqlCcpo3fVD/8joHeiJKuj4nHLYq/1 X-Received: by 2002:a63:842:: with SMTP id 63-v6mr24530367pgi.406.1529616004784; Thu, 21 Jun 2018 14:20:04 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1529616004; cv=none; d=google.com; s=arc-20160816; b=DIeUlyETXyVrgfqvrju/pCUyUERvRM5+zs9sofi/S8zgPzMCp92aSmYQNVHn1zOG49 13r2QX1UqowasUKrtc+FGYgh4kge0yuxXY2SzfnobhWaHi5bk0QpaxZwU9HkgTjCQvFw WRp77ZlMuI0fS7I8vklTIkS/sDlpkI+qlxMhxqjydOOrasfJSag8Z4Bc5kvtnPDZ5P7F vlgAMAxguvtBRKHoA60DrQK98MJi2LPIurv1JuPRFB5wDgsnOac43+jFkrkSM3+Pf0ul idqIizjYx7Re6t+xyWptyFvZdGzpX8ABqGQ7N7mpuYFyEqYmcBCGQmbWuPVPlrSHOkxE FwPw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=/Fl9K1lIw52JzVAMkPpY2YuF3det1Z/pAQbZpEHqtkE=; b=YB2ZtqHwttSS2bEINQtnIOahGlTDXxsHeGrMtqz2UDUUf0D7S90IlgTAJtsGYaVgJ0 GZ1951uEv1JaUIUwnMqKt+eAYY6/82SyBa0o7PxJcfhKktKSELEGCtkxmKgAmMRHhT/m CnMiWGWUcD/0wQgVOMZ1e/K+C9+MizkNy+A4VVi8phyBPYRQ0q+TE8eAzkf6KkaRJjvB 1kyp2YBO1Wc7tDvDh7dMECAiGVUVT27GzE4bw2tmFxwODsRB2rDYE3C+zTW2yyjr+f3j ZYYblHGmQ3p57dHf+zJK+o426x7f2fxGggg3WkucqQlIY0cikXDO4Tvf5jtKA7Hs5YUF SMsw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 43-v6si5749514pla.362.2018.06.21.14.19.50; Thu, 21 Jun 2018 14:20:04 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 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 S933552AbeFUVSc (ORCPT + 99 others); Thu, 21 Jun 2018 17:18:32 -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