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=-2.5 required=3.0 tests=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 D890AC43381 for ; Mon, 18 Mar 2019 17:40:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE7D120989 for ; Mon, 18 Mar 2019 17:40:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727392AbfCRRkg (ORCPT ); Mon, 18 Mar 2019 13:40:36 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:38828 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726513AbfCRRke (ORCPT ); Mon, 18 Mar 2019 13:40:34 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3A34BEBD; Mon, 18 Mar 2019 10:40:34 -0700 (PDT) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 696373F614; Mon, 18 Mar 2019 10:40:31 -0700 (PDT) Date: Mon, 18 Mar 2019 17:40:28 +0000 From: Sudeep Holla To: Oleg Nesterov Cc: x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Catalin Marinas , Will Deacon , Paul Mackerras , Michael Ellerman , Thomas Gleixner , Ingo Molnar , Richard Weinberger , jdike@addtoit.com, Steve Capper , Haibo Xu , Bin Lu , Andy Lutomirski Subject: Re: [PATCH v2 4/6] powerpc: use common ptrace_syscall_enter hook to handle _TIF_SYSCALL_EMU Message-ID: <20190318174028.GE18196@e107155-lin> References: <20190318104925.16600-1-sudeep.holla@arm.com> <20190318104925.16600-5-sudeep.holla@arm.com> <20190318172024.GB23521@redhat.com> <20190318172457.GD18196@e107155-lin> <20190318173341.GD23521@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190318173341.GD23521@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 18, 2019 at 06:33:41PM +0100, Oleg Nesterov wrote: > On 03/18, Sudeep Holla wrote: > > > > On Mon, Mar 18, 2019 at 06:20:24PM +0100, Oleg Nesterov wrote: > > > > > > Again, to me this patch just makes the code look worse. Honestly, I don't > > > think that the new (badly named) ptrace_syscall_enter() hook makes any sense. > > > > > > > Worse because we end up reading current_thread_info->flags twice ? > > Mostly because in my opinion ptrace_syscall_enter() buys nothing but makes > the caller's code less readable/understandable. > > Sure, this is subjective. > Based on what we have in that function today, I tend to agree. Will and Richard were in the opinion to consolidate SYSEMU handling(in the threads pointed in my cover letter). If there's a better way to achieve the same I am in for it. I have just tried to put something together based on what I could think of. -- Regards, Sudeep