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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 AC062C43381 for ; Mon, 1 Apr 2019 07:30:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 728222084B for ; Mon, 1 Apr 2019 07:30:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="dOLHWvqW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731947AbfDAHae (ORCPT ); Mon, 1 Apr 2019 03:30:34 -0400 Received: from merlin.infradead.org ([205.233.59.134]:34932 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731844AbfDAHad (ORCPT ); Mon, 1 Apr 2019 03:30:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=zlmRYHfrH8QLFcu62W2LRbXcqRcaCsgij+LfXxQree4=; b=dOLHWvqWXGsYKeS13csH9OXwr mgaIce+1RCJBLhsF7Qa0DM3GJcMiA3g7NUj34LbRIN21RwsjPDv4t2SjR0E1rbJ3881S20qQ3mX0Q 0RccOCRMHpYVvTA1wKovU0vyZpukT29+cb5KDMdtkGQEFmVNfGJrUUMWdvhJwIxNpoMNZKcOgA6vE Ip2tX+ReWWur5U0JI27ItoBzbROQQHC8QN1YuiXjm13RL8EkoeS99isGE429IiOLS5xy0ymocAWzT wCIY/+zLp0qGCKnnj1pRtnfgkWYs4G4qhl2ZKb+KZ7ejeCiyWRZIsXi2AYWw7RqMEmtG40QvILd/w DPiBye6dQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hArOm-00072e-6T; Mon, 01 Apr 2019 07:30:28 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id D99EE202BC431; Mon, 1 Apr 2019 09:30:24 +0200 (CEST) Date: Mon, 1 Apr 2019 09:30:24 +0200 From: Peter Zijlstra To: Thomas Gleixner Cc: LKML , x86@kernel.org, Andy Lutomirski , Josh Poimboeuf Subject: Re: [patch 04/14] x86/exceptions: Make IST index zero based Message-ID: <20190401073024.GB11158@hirez.programming.kicks-ass.net> References: <20190331214020.836098943@linutronix.de> <20190331215135.133741719@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190331215135.133741719@linutronix.de> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Mar 31, 2019 at 11:40:24PM +0200, Thomas Gleixner wrote: > --- a/arch/x86/include/asm/page_64_types.h > +++ b/arch/x86/include/asm/page_64_types.h > @@ -25,11 +25,14 @@ > #define IRQ_STACK_ORDER (2 + KASAN_STACK_ORDER) > #define IRQ_STACK_SIZE (PAGE_SIZE << IRQ_STACK_ORDER) > > -#define DOUBLEFAULT_STACK 1 > -#define NMI_STACK 2 > -#define DEBUG_STACK 3 > -#define MCE_STACK 4 > -#define N_EXCEPTION_STACKS 4 /* hw limit: 7 */ > +/* > + * The index for the tss.ist[] array. The hardware limit is 7 entries. > + */ > +#define DOUBLEFAULT_IST 0 > +#define NMI_IST 1 > +#define DEBUG_IST 2 > +#define MCE_IST 3 > +#define N_EXCEPTION_STACKS 4 Would it make sense to use an enum here?