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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 D4488CA9EAF for ; Thu, 24 Oct 2019 20:54:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0B3621929 for ; Thu, 24 Oct 2019 20:54:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728778AbfJXUyj (ORCPT ); Thu, 24 Oct 2019 16:54:39 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:33741 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728451AbfJXUyi (ORCPT ); Thu, 24 Oct 2019 16:54:38 -0400 Received: from p5b06da22.dip0.t-ipconnect.de ([91.6.218.34] helo=nanos) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iNk7u-0001L9-Jk; Thu, 24 Oct 2019 22:54:34 +0200 Date: Thu, 24 Oct 2019 22:54:33 +0200 (CEST) From: Thomas Gleixner To: Peter Zijlstra cc: Andy Lutomirski , LKML , X86 ML , Will Deacon , Paolo Bonzini , kvm list , linux-arch , Mike Rapoport , Josh Poimboeuf , Miroslav Benes Subject: Re: [patch V2 08/17] x86/entry: Move syscall irq tracing to C code In-Reply-To: <20191024174044.GJ4114@hirez.programming.kicks-ass.net> Message-ID: References: <20191023122705.198339581@linutronix.de> <20191023123118.386844979@linutronix.de> <20191024174044.GJ4114@hirez.programming.kicks-ass.net> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 24 Oct 2019, Peter Zijlstra wrote: > On Thu, Oct 24, 2019 at 09:24:13AM -0700, Andy Lutomirski wrote: > > On Wed, Oct 23, 2019 at 2:30 PM Andy Lutomirski wrote: > > > > > > On Wed, Oct 23, 2019 at 5:31 AM Thomas Gleixner wrote: > > > > > > > > Interrupt state tracing can be safely done in C code. The few stack > > > > operations in assembly do not need to be covered. > > > > > > > > Remove the now pointless indirection via .Lsyscall_32_done and jump to > > > > swapgs_restore_regs_and_return_to_usermode directly. > > > > > > This doesn't look right. > > > > Well, I feel a bit silly. I read this: Happened to me before. Don't worry. > > > > > > > #define SYSCALL_EXIT_WORK_FLAGS \ > > > > @@ -279,6 +282,9 @@ static void syscall_slow_exit_work(struc > > > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > and I applied the diff in my head to the wrong function, and I didn't > > notice that it didn't really apply there. Oddly, gitweb gets this > > I had the same when reviewing these patches; I was almost going to ask > tglx about it on IRC when the penny dropped. diff is weird at times. Thanks, tglx