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=unavailable 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 E83C4C4360F for ; Mon, 18 Mar 2019 17:42:39 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 670F12070D for ; Mon, 18 Mar 2019 17:42:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 670F12070D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 44NNms2QMMzDqLM for ; Tue, 19 Mar 2019 04:42:37 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=arm.com (client-ip=217.140.101.70; helo=foss.arm.com; envelope-from=sudeep.holla@arm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=arm.com Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by lists.ozlabs.org (Postfix) with ESMTP id 44NNkX1lwkzDqK9 for ; Tue, 19 Mar 2019 04:40:35 +1100 (AEDT) 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 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) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Haibo Xu , Steve Capper , Catalin Marinas , jdike@addtoit.com, x86@kernel.org, Will Deacon , linux-kernel@vger.kernel.org, Bin Lu , Richard Weinberger , Ingo Molnar , Paul Mackerras , Andy Lutomirski , Thomas Gleixner , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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