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=-5.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 79BD9C433FF for ; Thu, 1 Aug 2019 07:37:52 +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 4B0DF206B8 for ; Thu, 1 Aug 2019 07:37:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Myf9Rgj0"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="qB1YTh06" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4B0DF206B8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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=gmdnmEF8Y4CSi07Ef/piAkwOlk1iOTE/e42XKpGj/8I=; b=Myf9Rgj0ljHm6V uzDU8sbSNslmvDWhL90cfNGyLocog9bJLI/M8vxGpnOIAX3QGeYK1DazDLkKwlnj5A74JH9UUB5AF gdTPJQFod8dR/OHvFkhtlgd8KI1fh82SWdXXNH8VcfUj7avJmJ4x6FDNxMEIOmlHfS7OmTCIgO7Sk ZOsRBJMi6MbUAzODCXJuo14B8BhZf8xrzZvoFnkHYB3roIdvPOIVxsFC8HaK16zhbGXP2GKGJ2w28 gOAETumcK2S9oy0thPQBlMHoYpuPXISXXcEl7KlljB89Q9QXNoJbBP9SaYlhrToETO1KHGvfSSnfD z6ImFhQWmYJGyjIoRH7A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1ht5ek-0003HQ-0C; Thu, 01 Aug 2019 07:37:46 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1ht5eg-0003H5-V0 for linux-arm-kernel@lists.infradead.org; Thu, 01 Aug 2019 07:37:44 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C46EC206B8; Thu, 1 Aug 2019 07:37:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564645062; bh=sOf2S0CiEG1ZaH20+DYy2OtudWMWVUNo515WBoje4Fo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qB1YTh06fJbasGpBvg62Fur5l+pTa927ewmGW+JK8xFgsz+l9oKu1NCXMvhNd9pz/ cUdBcq5fI/kp2K6UnIHMSqIloQX1CvMe/pi0G3KpyMW51Sozf4tWn4lpqFX7tjqQgZ EpuvgXEoCiN5JGif8mykFQQyloj4Ehxz2JijKmS4= Date: Thu, 1 Aug 2019 08:37:37 +0100 From: Will Deacon To: Masami Hiramatsu Subject: Re: [PATCH v3 3/4] arm64: Make debug exception handlers visible from RCU Message-ID: <20190801073737.wrhespf5xh3qudil@willie-the-truck> References: <156404254387.2020.886452004489353899.stgit@devnote2> <156404257493.2020.7940525305482369976.stgit@devnote2> <20190731172602.36hdk3yb3w6uihbu@willie-the-truck> <20190801143225.e61e38ce7a701407b19f8008@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190801143225.e61e38ce7a701407b19f8008@kernel.org> User-Agent: NeoMutt/20170113 (1.7.2) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190801_003743_025523_601F5AC8 X-CRM114-Status: GOOD ( 16.20 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dan Rue , Daniel Diaz , Anders Roxell , Catalin Marinas , Naresh Kamboju , Will Deacon , linux-kernel@vger.kernel.org, Matt Hart , "Paul E . McKenney" , 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 Hi Masami, On Thu, Aug 01, 2019 at 02:32:25PM +0900, Masami Hiramatsu wrote: > On Wed, 31 Jul 2019 18:26:03 +0100 > Will Deacon wrote: > > On Thu, Jul 25, 2019 at 05:16:15PM +0900, Masami Hiramatsu wrote: > > > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > > > index 9568c116ac7f..ed6c55c87fdc 100644 > > > --- a/arch/arm64/mm/fault.c > > > +++ b/arch/arm64/mm/fault.c > > > @@ -777,6 +777,42 @@ void __init hook_debug_fault_code(int nr, > > > debug_fault_info[nr].name = name; > > > } > > > > > > +/* > > > + * In debug exception context, we explicitly disable preemption. > > > > Maybe add "despite having interrupts disabled"? > > OK, I'll add it. > > > > + * This serves two purposes: it makes it much less likely that we would > > > + * accidentally schedule in exception context and it will force a warning > > > + * if we somehow manage to schedule by accident. > > > + */ > > > +static void debug_exception_enter(struct pt_regs *regs) > > > +{ > > > + if (user_mode(regs)) { > > > + RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); > > > + } else { > > > + /* > > > + * We might have interrupted pretty much anything. In > > > + * fact, if we're a debug exception, we can even interrupt > > > + * NMI processing. We don't want this code makes in_nmi() > > > + * to return true, but we need to notify RCU. > > > + */ > > > + rcu_nmi_enter(); > > > + } > > > + > > > + preempt_disable(); > > > > If you're addingt new functions for entry/exit, maybe move the > > trace_hardirqs_{on,off}() calls in here too? > > OK, let's move it in these functions. Brill, thanks. Please just resend this patch, as I can pick the other three up as they are. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel