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=-11.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 EBA95C4363D for ; Thu, 24 Sep 2020 09:30:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9320523787 for ; Thu, 24 Sep 2020 09:30:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600939809; bh=0tWg5uutNp4VicmL+sqHzCyXrTd3PNp40gTufqKbwvA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=Icpj2WS6PQRZlBrlrr3Drny7AY8ZghodzM0zWxCCCYg3/fDtRjyYsdg6OSWjdX9q5 ULN15bE+2wDt9oQDP7BCzm9Mq3PwOdslesD9o/O7k4/6s+GwngcrYcMU7kuI7QMPuR SwxHq012QjlKdnRPNDameI/A+sYhAp8lkVOwjoHE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727351AbgIXJaI (ORCPT ); Thu, 24 Sep 2020 05:30:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:39346 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726244AbgIXJaH (ORCPT ); Thu, 24 Sep 2020 05:30:07 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 9D59422208; Thu, 24 Sep 2020 09:30:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600939806; bh=0tWg5uutNp4VicmL+sqHzCyXrTd3PNp40gTufqKbwvA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=m9gUatUxl+q8JunT56Houb9u/hWyl2mi62H3fPEp8YmskYgJKIpfp5IPgvb22RA4B HU3jxJGAl2BMwPc6qQA4OIn2ogNui8aSGfYVfNEhwYDPFP+72IlHHJh2F4eUKpRBDX yJiHRjWTgrDkTmmprL6auKCWawtJmeg803nLeTpI= Received: from [148.252.128.132] (helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kLNZk-00EYup-HG; Thu, 24 Sep 2020 10:30:04 +0100 Date: Thu, 24 Sep 2020 10:29:57 +0100 Message-ID: <875z83r08a.wl-maz@kernel.org> From: Marc Zyngier To: Guillaume Tucker Cc: Valentin Schneider , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sumit Garg , kernel-team@android.com, Florian Fainelli , Russell King , Jason Cooper , Saravana Kannan , Andrew Lunn , Catalin Marinas , Gregory Clement , Thomas Gleixner , Will Deacon , kernelci-results@groups.io Subject: Re: [PATCH v3 16/16] ARM: Remove custom IRQ stat accounting In-Reply-To: References: <20200901144324.1071694-1-maz@kernel.org> <20200901144324.1071694-17-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 EasyPG/1.0.0 Emacs/26.3 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 148.252.128.132 X-SA-Exim-Rcpt-To: guillaume.tucker@collabora.com, valentin.schneider@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, sumit.garg@linaro.org, kernel-team@android.com, f.fainelli@gmail.com, linux@arm.linux.org.uk, jason@lakedaemon.net, saravanak@google.com, andrew@lunn.ch, catalin.marinas@arm.com, gregory.clement@bootlin.com, tglx@linutronix.de, will@kernel.org, kernelci-results@groups.io X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Guillaume, On Thu, 24 Sep 2020 10:00:09 +0100, Guillaume Tucker wrote: > > Hi Marc, > > On 01/09/2020 15:43, Marc Zyngier wrote: > > Let's switch the arm code to the core accounting, which already > > does everything we need. > > > > Reviewed-by: Valentin Schneider > > Signed-off-by: Marc Zyngier > > --- > > arch/arm/include/asm/hardirq.h | 17 ----------------- > > arch/arm/kernel/smp.c | 20 ++++---------------- > > 2 files changed, 4 insertions(+), 33 deletions(-) > > This appears to be causing a NULL pointer dereference on > beaglebone-black, it got bisected automatically several times. > None of the other platforms in the KernelCI labs appears to be > affected. Hmm. My bet is that because this is a UP machine running an SMP kernel, and I fell into the trap of forgetting about this 32bit configuration. I expect the following patch to fix it. Please give it a go if you can (I'm away at the moment and can't test much, and do not have any physical 32bit machine to test this on). diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 00327fa74b01..b4e3d336dc33 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -531,7 +531,12 @@ void show_ipi_list(struct seq_file *p, int prec) unsigned int cpu, i; for (i = 0; i < NR_IPI; i++) { - unsigned int irq = irq_desc_get_irq(ipi_desc[i]); + unsigned int irq; + + if (!ipi_desc[i]) + continue; + + irq = irq_desc_get_irq(ipi_desc[i]); seq_printf(p, "%*s%u: ", prec - 1, "IPI", i); for_each_online_cpu(cpu) Thanks, M. -- Without deviation from the norm, progress is not possible.