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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 8630CC34047 for ; Wed, 19 Feb 2020 16:57:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B7AE2464E for ; Wed, 19 Feb 2020 16:57:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="WTdKP+F8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726682AbgBSQ5E (ORCPT ); Wed, 19 Feb 2020 11:57:04 -0500 Received: from mail.skyhub.de ([5.9.137.197]:55246 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726528AbgBSQ5D (ORCPT ); Wed, 19 Feb 2020 11:57:03 -0500 Received: from zn.tnic (p200300EC2F095500C57DC876B1A4488F.dip0.t-ipconnect.de [IPv6:2003:ec:2f09:5500:c57d:c876:b1a4:488f]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 498D21EC0CD9; Wed, 19 Feb 2020 17:57:02 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1582131422; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=wBQ/V+Owq77r5fLvZwGz8LVJdcyZkflLLKgxNcXUSdA=; b=WTdKP+F8vPWRVBlx/zejK9TZPtBxxTegXT2VRNnuYGBmVzrcYo9tT3T30aH1SPdsy7bEX5 rIpJWs1GMLcTov1wdGw4WAkVEg0mDXpqNXsT3qjsPfnyd0QvTKyMPvaxtLsjTqM0EZo3p7 MmxGKc8Z9xW4JBr2/eniYUv1QjEa/IM= Date: Wed, 19 Feb 2020 17:56:50 +0100 From: Borislav Petkov To: Steven Rostedt Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, mingo@kernel.org, joel@joelfernandes.org, gregkh@linuxfoundation.org, gustavo@embeddedor.com, tglx@linutronix.de, paulmck@kernel.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, luto@kernel.org, tony.luck@intel.com, frederic@kernel.org, dan.carpenter@oracle.com, mhiramat@kernel.org, Will Deacon , Marc Zyngier , Michael Ellerman , Petr Mladek Subject: Re: [PATCH v3 01/22] hardirq/nmi: Allow nested nmi_enter() Message-ID: <20200219165650.GB32346@zn.tnic> References: <20200219144724.800607165@infradead.org> <20200219150744.428764577@infradead.org> <20200219103126.33f67cf3@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200219103126.33f67cf3@gandalf.local.home> 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 Wed, Feb 19, 2020 at 10:31:26AM -0500, Steven Rostedt wrote: > Probably should document somewhere (in a comment above nmi_enter()?) > that we allow nmi_enter() to nest up to 15 times. Yah, and can we make the BUG_ON() WARN_ON or so instead, so that there's at least a chance to be able to catch it for debugging. Or is the box going to be irreparably wedged after the 4 bits overflow? -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette