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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 7BD73C43441 for ; Thu, 29 Nov 2018 17:44:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 34F89213A2 for ; Thu, 29 Nov 2018 17:44:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 34F89213A2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org 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 S1730645AbeK3EuS (ORCPT ); Thu, 29 Nov 2018 23:50:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:50242 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728429AbeK3EuR (ORCPT ); Thu, 29 Nov 2018 23:50:17 -0500 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 75E5821104; Thu, 29 Nov 2018 17:44:06 +0000 (UTC) Date: Thu, 29 Nov 2018 12:44:04 -0500 From: Steven Rostedt To: Linus Torvalds Cc: Andy Lutomirski , Josh Poimboeuf , Peter Zijlstra , Andrew Lutomirski , "the arch/x86 maintainers" , Linux List Kernel Mailing , Ard Biesheuvel , Ingo Molnar , Thomas Gleixner , mhiramat@kernel.org, jbaron@akamai.com, Jiri Kosina , David.Laight@aculab.com, bp@alien8.de, julia@ni.com, jeyu@kernel.org, Peter Anvin Subject: Re: [PATCH v2 4/4] x86/static_call: Add inline static call implementation for x86-64 Message-ID: <20181129124404.2fe55dd0@gandalf.local.home> In-Reply-To: References: <20181126160217.GR2113@hirez.programming.kicks-ass.net> <20181126171036.chcbmb35ygpxziub@treble> <20181126175624.bruqfbkngbucpvxr@treble> <20181126200801.GW2113@hirez.programming.kicks-ass.net> <20181126212628.4apztfazichxnt7r@treble> <20181127084330.GX2113@hirez.programming.kicks-ass.net> <20181129094210.GC2131@hirez.programming.kicks-ass.net> <20181129143853.GO2131@hirez.programming.kicks-ass.net> <20181129163342.tp5wlfcyiazwwyoh@treble> <0A629D30-ADCF-4159-9443-E5727146F65F@amacapital.net> <20181129121307.12393c57@gandalf.local.home> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 29 Nov 2018 09:35:11 -0800 Linus Torvalds wrote: > On Thu, Nov 29, 2018 at 9:13 AM Steven Rostedt wrote: > > > > No, we really do need to sync after we change the second part of the > > command with the int3 on it. Unless there's another way to guarantee > > that the full instruction gets seen when we replace the int3 with the > > finished command. > > Making sure the call instruction is aligned with the I$ fetch boundary > should do that. > > It's not in the SDM, but neither was our current behavior - we > were/are just relying on "it will work". > Well, the current method (as Jiri mentioned) did get the OK from at least Intel (and that was with a lot of arm twisting to do so). -- Steve