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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 89C6BC04AB5 for ; Mon, 3 Jun 2019 17:22:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 61B1827332 for ; Mon, 3 Jun 2019 17:22:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729820AbfFCRW6 (ORCPT ); Mon, 3 Jun 2019 13:22:58 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:56362 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728903AbfFCRW5 (ORCPT ); Mon, 3 Jun 2019 13:22:57 -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 16F2CA78; Mon, 3 Jun 2019 10:22:57 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8CDEE3F5AF; Mon, 3 Jun 2019 10:22:54 -0700 (PDT) Date: Mon, 3 Jun 2019 18:22:52 +0100 From: Catalin Marinas To: Sudeep Holla , Andy Lutomirski Cc: x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Will Deacon , Oleg Nesterov , Richard Weinberger , jdike@addtoit.com, Steve Capper , Haibo Xu , Bin Lu , Thomas Gleixner , Ingo Molnar , Borislav Petkov Subject: Re: [PATCH v4 2/4] x86: simplify _TIF_SYSCALL_EMU handling Message-ID: <20190603172251.GG63283@arrakis.emea.arm.com> References: <20190523090618.13410-1-sudeep.holla@arm.com> <20190523090618.13410-3-sudeep.holla@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190523090618.13410-3-sudeep.holla@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 23, 2019 at 10:06:16AM +0100, Sudeep Holla wrote: > The usage of emulated/_TIF_SYSCALL_EMU flags in syscall_trace_enter > seems to be bit overcomplicated than required. Let's simplify it. > > Cc: Andy Lutomirski > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Acked-by: Oleg Nesterov > Signed-off-by: Sudeep Holla > --- > arch/x86/entry/common.c | 17 ++++++----------- > 1 file changed, 6 insertions(+), 11 deletions(-) > > diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c > index a986b3c8294c..0a61705d62ec 100644 > --- a/arch/x86/entry/common.c > +++ b/arch/x86/entry/common.c > @@ -72,23 +72,18 @@ static long syscall_trace_enter(struct pt_regs *regs) > > struct thread_info *ti = current_thread_info(); > unsigned long ret = 0; > - bool emulated = false; > u32 work; > > if (IS_ENABLED(CONFIG_DEBUG_ENTRY)) > BUG_ON(regs != task_pt_regs(current)); > > - work = READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY; > + work = READ_ONCE(ti->flags); > > - if (unlikely(work & _TIF_SYSCALL_EMU)) > - emulated = true; > - > - if ((emulated || (work & _TIF_SYSCALL_TRACE)) && > - tracehook_report_syscall_entry(regs)) > - return -1L; > - > - if (emulated) > - return -1L; > + if (work & (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU)) { > + ret = tracehook_report_syscall_entry(regs); > + if (ret || (work & _TIF_SYSCALL_EMU)) > + return -1L; > + } Andy (or the other x86 folk), could I please get an ack on this patch? I plan to queue this series through the arm64 tree (though if you want to merge it separately, it looks like an independent clean-up with no dependencies on the other patches). Thanks. -- Catalin