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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 910B4C4BA13 for ; Wed, 26 Feb 2020 16:28:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60447206E6 for ; Wed, 26 Feb 2020 16:28:27 +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="tw6kKo2D" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727262AbgBZQ20 (ORCPT ); Wed, 26 Feb 2020 11:28:26 -0500 Received: from merlin.infradead.org ([205.233.59.134]:57622 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726764AbgBZQ2Z (ORCPT ); Wed, 26 Feb 2020 11:28:25 -0500 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; bh=cxDmKJums1Yw5hsbamtZg0/vSQBgjr5D+7wgCmatioE=; b=tw6kKo2Duv8Hk8DCmU2Xw/Ra/J Qnq5Oq+a1gJJf1W+EIJgu71Gh+AELvvQbZryiwZaIIQiHvqweVidrqUqkMKRu/TdF/Yv8FBFzQ1iW J8HDAjmwh6oI3xPDzfKwH+0jIUV5pQGwlAiz2zhTZMAfWQlRSbAxsscMr3Y0qPGXB+GyOa6bvgA8d PWOCPkck7w9LLWjBAVW4oc3dKLYa/HS9aJ36azl10ZoeLRJ0AiApUh+YNrq4eGxFEWJhX6a4xXdQt yaRjCjPmeRF4dtUHulb3JolKDB+RwKalmxxPveWvINFMTsjho+0tV/ISCHaqqTN9xECPJlr/QS6Wy bhemJkyA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6zXh-0001Jt-FF; Wed, 26 Feb 2020 16:28:13 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 3F689300130; Wed, 26 Feb 2020 17:26:16 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id BF42F2B746023; Wed, 26 Feb 2020 17:28:11 +0100 (CET) Date: Wed, 26 Feb 2020 17:28:11 +0100 From: Peter Zijlstra To: Andy Lutomirski Cc: Thomas Gleixner , LKML , X86 ML , Steven Rostedt , Brian Gerst , Juergen Gross , Paolo Bonzini , Arnd Bergmann Subject: Re: [patch 13/16] x86/entry: Move irqflags and context tracking to C for simple idtentries Message-ID: <20200226162811.GA18400@hirez.programming.kicks-ass.net> References: <20200225223321.231477305@linutronix.de> <20200225224145.444611199@linutronix.de> <20200226080538.GO18400@hirez.programming.kicks-ass.net> <20200226092018.GR18400@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Wed, Feb 26, 2020 at 07:11:39AM -0800, Andy Lutomirski wrote: > In some sense, this is a weakness of the magic macro approach. Some > of the entries just want to have code that runs before all the entry > fixups. This is an example of it. So are the cr2 reads. It can all > be made to work, but it's a bit gross. Right. In my current pile (new patche since last posting) I also have one that makes #DB save-clear/restore DR7. I got it early enough that only a watchpoint on the task stack can still screw us over, since I also included your patch that excludes cpu_entry_area. Pushing it earlier still would require calling into C from the entry stack, which I know is on your todo list, but we're not quite there yet.