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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 E464AC433E0 for ; Thu, 14 May 2020 09:20:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC5202065D for ; Thu, 14 May 2020 09:20:34 +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="U4jpM5eg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726157AbgENJUd (ORCPT ); Thu, 14 May 2020 05:20:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725878AbgENJUd (ORCPT ); Thu, 14 May 2020 05:20:33 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21019C061A0C for ; Thu, 14 May 2020 02:20:33 -0700 (PDT) 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=/uwK69cKvIIvKOO5ymbYqzBNjG47n+IyGnvHw5vJrl0=; b=U4jpM5egpZ5/F/T2TZKbxuiiMB kGuNxkxBQX50aexS/vNQcdKYfMcMk5FcXYzlSSvUv90v4fMYALjiVnyRPZz6KEZUU4Cy6kJ+aHM4/ Uvmi5y6228cvJvA6OyzsB8sQSgC3XtT6ER7lG8pDpXtiApswWFfb1gwo6Ar0wHhhl8W52j1uy5wIQ boVDvMxTIcxxYneZMAxQmEbe8qK0hZHF40KYTz3Ht9D4F93WPiRaMZeWCkSnH8+i+3+xgbltYArkx 6RdAIc9iqbsmHOvbpZCh9TsCtSpgmfAtTK0tQtHMvLxEFSH+yx2S5QYpjat3P0vwioegH4lzn8jov XUmy0IEA==; 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 1jZA1m-0005lb-Gc; Thu, 14 May 2020 09:19:43 +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 74E72301205; Thu, 14 May 2020 11:19:40 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 47CF724C14F19; Thu, 14 May 2020 11:19:40 +0200 (CEST) Date: Thu, 14 May 2020 11:19:40 +0200 From: Peter Zijlstra To: Mathieu Desnoyers Cc: Thomas Gleixner , rostedt , linux-kernel , x86 , paulmck , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , "Joel Fernandes, Google" , Boris Ostrovsky , Juergen Gross , Brian Gerst , Josh Poimboeuf , Will Deacon Subject: Re: [patch V4 part 1 05/36] x86/entry: Flip _TIF_SIGPENDING and _TIF_NOTIFY_RESUME handling Message-ID: <20200514091940.GS2978@hirez.programming.kicks-ass.net> References: <20200505131602.633487962@linutronix.de> <20200505134058.560059744@linutronix.de> <1970736614.19996.1589403401588.JavaMail.zimbra@efficios.com> <20200513171047.04c2c10e@gandalf.local.home> <87v9kzz862.fsf@nanos.tec.linutronix.de> <1779765540.20682.1589424713646.JavaMail.zimbra@efficios.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1779765540.20682.1589424713646.JavaMail.zimbra@efficios.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 13, 2020 at 10:51:53PM -0400, Mathieu Desnoyers wrote: > Yes, I'm very well aware of this. But the patch commit message states: > > "Make sure task_work runs before any kind of userspace -- very much > including signals -- is invoked." > > which seems to imply that "userspace" can be "invoked" before the task_work > runs. Which makes no sense whatsoever. Hence my confused state. I initially missed the run_task_work in the signal handling maze. Then later figured this order still made more sense, but apparently there's an actual problem. I've no problem with the patch getting dropped.