From nobody Sun Dec 28 02:40:24 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4CEBCC4332F for ; Wed, 13 Dec 2023 16:34:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233147AbjLMQeo (ORCPT ); Wed, 13 Dec 2023 11:34:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232663AbjLMQem (ORCPT ); Wed, 13 Dec 2023 11:34:42 -0500 Received: from mail-oo1-xc2e.google.com (mail-oo1-xc2e.google.com [IPv6:2607:f8b0:4864:20::c2e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38C1998 for ; Wed, 13 Dec 2023 08:34:49 -0800 (PST) Received: by mail-oo1-xc2e.google.com with SMTP id 006d021491bc7-59093f6c94aso2375406eaf.0 for ; Wed, 13 Dec 2023 08:34:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1702485287; x=1703090087; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=zJ6yzzdHCK6etXayum+0eGdCGB2aFZEnSrrZblNix5w=; b=R+YhY2IBlfBgXuGL1bpFveRtSQR9n0PiMGYM4wqdsvdj38EURvCi5SE2KyX7pLol1V Ux74x1K4AUNUKCgGB6WESiM+54J14rLQmvG4l0pqIEHqsSFDrf3IljRU2kfc7SKuIER3 yYIcbJp0DjUKVeFE689yIz32ESMhle7NPXbzOdiBq/oFk2DuOkmbqnk/5LfNPEK7XfAV /GWzoXGYMRD0T6psf3cZFiYarwpKR39/4X3eVd6SLVWsdKmCPB0exQQrjzL7v8zOZiTi 856ydvvV06Dh0PPi5jPsujAhasB1itWXPeIP5PNslI43KOssBndqjG2Ql49PZTExKdY+ kqxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702485287; x=1703090087; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=zJ6yzzdHCK6etXayum+0eGdCGB2aFZEnSrrZblNix5w=; b=kcllg9wLL8G7GxQhWPp0tvUUIcgyHr9nctEHDonTbjtElWdnO82p2i057YGJgURvkY k9aQy6ZLv2cg2eQVclX5hL10/6qexyxAGhk/9QgqPSkKwc4PtGUpXkNSFiJr2ty75Bqf 7wcjbZkvvPUZddwv6+WqkXcfnsTIjNzrmhZZ08ED5xT8+5idqp4w+N0ITf+HJXkujWKA 6NjV97YtLfM3hcx35Q6PdIcq1p+TAg8kdfT2JNFnOe7txk0KgURkYIbMT4p0NSUHhmmN uuDCX8zq7WSwjlBblwCqaW6ncCbU3EQH/fJsQqRiVtO1jgCwReNGThuyDXSi6qhFs4z8 M6cA== X-Gm-Message-State: AOJu0Yw5WNEHboq9s01IaLhhinsCSoUOhVg/MfKOfiK8vPB8XvinrYeZ g+abiKtzkXsJOHr0THKlcGYTrDc9rQ== X-Google-Smtp-Source: AGHT+IH9N99VQwIawvjz/NKYBGbiBOggFlFZ3Aq+V/+voSZvc8Rizdq+CDR5fdnvazMceMuNCFSKjQ== X-Received: by 2002:a4a:e825:0:b0:590:e78e:3e37 with SMTP id d5-20020a4ae825000000b00590e78e3e37mr2884222ood.1.1702485287640; Wed, 13 Dec 2023 08:34:47 -0800 (PST) Received: from citadel.lan ([2600:6c4a:4d3f:6d5c::1019]) by smtp.gmail.com with ESMTPSA id j11-20020a4ad2cb000000b005907ad9f302sm3104901oos.37.2023.12.13.08.34.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Dec 2023 08:34:47 -0800 (PST) From: Brian Gerst To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: Ingo Molnar , Thomas Gleixner , Borislav Petkov , "H . Peter Anvin" , Peter Zijlstra , Linus Torvalds , Brian Gerst Subject: [PATCH 1/3] x86: Move TSS and LDT to end of the GDT Date: Wed, 13 Dec 2023 11:34:41 -0500 Message-ID: <20231213163443.70490-2-brgerst@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231213163443.70490-1-brgerst@gmail.com> References: <20231213163443.70490-1-brgerst@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This will make testing for system segments easier. Signed-off-by: Brian Gerst --- arch/x86/include/asm/segment.h | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index 9d6411c65920..a155843d0c37 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -83,8 +83,8 @@ * 13 - kernel data segment * 14 - default user CS * 15 - default user DS - * 16 - TSS <=3D=3D=3D cacheline #5 - * 17 - LDT + * 16 - unused <=3D=3D=3D cacheline #5 + * 17 - unused * 18 - PNPBIOS support (16->32 gate) * 19 - PNPBIOS support * 20 - PNPBIOS support <=3D=3D=3D cacheline #6 @@ -97,8 +97,11 @@ * 26 - ESPFIX small SS * 27 - per-cpu [ offset to per-cpu data area ] * 28 - VDSO getcpu - * 29 - unused - * 30 - unused + * + * ------- start of system segments: + * + * 29 - TSS + * 30 - LDT * 31 - TSS for double fault handler */ #define GDT_ENTRY_TLS_MIN 6 @@ -108,8 +111,6 @@ #define GDT_ENTRY_KERNEL_DS 13 #define GDT_ENTRY_DEFAULT_USER_CS 14 #define GDT_ENTRY_DEFAULT_USER_DS 15 -#define GDT_ENTRY_TSS 16 -#define GDT_ENTRY_LDT 17 #define GDT_ENTRY_PNPBIOS_CS32 18 #define GDT_ENTRY_PNPBIOS_CS16 19 #define GDT_ENTRY_PNPBIOS_DS 20 @@ -121,6 +122,10 @@ #define GDT_ENTRY_PERCPU 27 #define GDT_ENTRY_CPUNODE 28 =20 +/* Start of system segments */ + +#define GDT_ENTRY_TSS 29 +#define GDT_ENTRY_LDT 30 #define GDT_ENTRY_DOUBLEFAULT_TSS 31 =20 /* @@ -188,20 +193,22 @@ #define GDT_ENTRY_DEFAULT_USER_DS 5 #define GDT_ENTRY_DEFAULT_USER_CS 6 =20 -/* Needs two entries */ -#define GDT_ENTRY_TSS 8 -/* Needs two entries */ -#define GDT_ENTRY_LDT 10 - #define GDT_ENTRY_TLS_MIN 12 #define GDT_ENTRY_TLS_MAX 14 =20 #define GDT_ENTRY_CPUNODE 15 =20 +/* Start of system segments */ + +/* Needs two entries */ +#define GDT_ENTRY_TSS 16 +/* Needs two entries */ +#define GDT_ENTRY_LDT 18 + /* * Number of entries in the GDT table: */ -#define GDT_ENTRIES 16 +#define GDT_ENTRIES 20 =20 /* * Segment selector values corresponding to the above entries: @@ -219,6 +226,8 @@ =20 #endif =20 +#define GDT_SYSTEM_START GDT_ENTRY_TSS + #define IDT_ENTRIES 256 #define NUM_EXCEPTION_VECTORS 32 =20 --=20 2.43.0