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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 6C2E7C43381 for ; Mon, 4 Mar 2019 12:24:22 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 381532075B for ; Mon, 4 Mar 2019 12:24:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="NmHBanr5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 381532075B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Mime-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=VBWcoKsynsf0zHYQbcN6qLMi2Q84txFofHuoJJ4QHpU=; b=NmHBanr5V0/d2w bmUImF9K+p0+zCkPdZAJF5/9E53XuSLPlkFTcGwMgOzRAzYflwu/XpDoIk1uHwM6BNgohzECSCXfP vIY71tIQmo6YRXaEy5cyhA5BIJIsiLe8d+9kEnUaDu7zZBilIiNgL8Ev+Ylqf1BMcbfAfUeQn+wOJ YmqjAnpNip7UfwLibLgui+R95fteNAKF31XSPFnfkgKp+7QViP9A9F2QIob1NhIMemL+b18gbyuGf VFj07CvFRrkFoqVv6E5UQMEwanSRNaQoY2X28ZJhu11hA2KaFASlq65a2I4Qbqq+ffHzHHB4ijU+/ YGNs3JGfVIPQsCYATa8g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h0mdl-0005Rp-JY; Mon, 04 Mar 2019 12:24:17 +0000 Received: from gate.crashing.org ([63.228.1.57]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1h0mdh-0005Qb-UZ for linux-arm-kernel@lists.infradead.org; Mon, 04 Mar 2019 12:24:15 +0000 Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id x24CNZlQ031671; Mon, 4 Mar 2019 06:23:35 -0600 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id x24CNWqJ031670; Mon, 4 Mar 2019 06:23:32 -0600 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Mon, 4 Mar 2019 06:23:32 -0600 From: Segher Boessenkool To: Sudeep Holla Subject: Re: [PATCH 2/6] ptrace: introduce ptrace_syscall_enter to consolidate PTRACE_SYSEMU handling Message-ID: <20190304122331.GG3969@gate.crashing.org> References: <20190228183220.15626-1-sudeep.holla@arm.com> <20190228183220.15626-3-sudeep.holla@arm.com> <20190304104643.GA28643@e107155-lin> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190304104643.GA28643@e107155-lin> User-Agent: Mutt/1.4.2.3i X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190304_042414_192671_406249F7 X-CRM114-Status: UNSURE ( 9.72 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Haibo Xu \(Arm Technology China\)" , Steve Capper , Catalin Marinas , "jdike@addtoit.com" , "x86@kernel.org" , Will Deacon , "linux-kernel@vger.kernel.org" , Oleg Nesterov , Ingo Molnar , Paul Mackerras , Richard Weinberger , Thomas Gleixner , "Bin Lu \(Arm Technology China\)" , "linuxppc-dev@lists.ozlabs.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Mar 04, 2019 at 10:46:43AM +0000, Sudeep Holla wrote: > On Mon, Mar 04, 2019 at 08:03:47AM +0000, Haibo Xu (Arm Technology China) wrote: > > On 2019/3/1 2:32, Sudeep Holla wrote: > > > +long ptrace_syscall_enter(struct pt_regs *regs) > > > +{ > > > +#ifdef TIF_SYSCALL_EMU > > > + if (test_thread_flag(TIF_SYSCALL_EMU)) { > > > + if (tracehook_report_syscall_entry(regs)); > > > > Shall we remove the semi-colon at end of the above line? > > Added intentionally to keep GCC happy. GCC warns because the user explicitly asked for it, with __must_check. If you want to do things with an "if" like this, you should write e.g. if (tracehook_report_syscall_entry(regs)) /* * We can ignore the return code here, because of * X and Y and Z. */ ; Or it probably is nicer to use a block: if (tracehook_report_syscall_entry(regs)) { /* * We can ignore the return code here, because of * X and Y and Z. */ } The point is, you *always* should have a nice fat comment if you are ignoring the return code of a __must_check function. Segher _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel