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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 14321C43461 for ; Fri, 7 May 2021 09:16:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D20746144F for ; Fri, 7 May 2021 09:16:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236109AbhEGJRb convert rfc822-to-8bit (ORCPT ); Fri, 7 May 2021 05:17:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:39486 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235829AbhEGJQm (ORCPT ); Fri, 7 May 2021 05:16:42 -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 4F3ED61426; Fri, 7 May 2021 09:15:42 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1lewaC-00BQn9-4H; Fri, 07 May 2021 10:15:40 +0100 Date: Fri, 07 May 2021 10:15:39 +0100 Message-ID: <87h7jeq4zo.wl-maz@kernel.org> From: Marc Zyngier To: Pali =?UTF-8?B?Um9ow6Fy?= Cc: Lorenzo Pieralisi , Thomas Petazzoni , Rob Herring , Bjorn Helgaas , Russell King , Marek =?UTF-8?B?QmVow7pu?= , Remi Pommarel , Xogium , Tomasz Maciej Nowak , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 12/42] PCI: aardvark: Check for virq mapping when processing INTx IRQ In-Reply-To: <20210506153153.30454-13-pali@kernel.org> References: <20210506153153.30454-1-pali@kernel.org> <20210506153153.30454-13-pali@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (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=UTF-8 Content-Transfer-Encoding: 8BIT X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: pali@kernel.org, lorenzo.pieralisi@arm.com, thomas.petazzoni@bootlin.com, robh@kernel.org, bhelgaas@google.com, rmk+kernel@armlinux.org.uk, kabel@kernel.org, repk@triplefau.lt, contact@xogium.me, tmn505@gmail.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org 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 On Thu, 06 May 2021 16:31:23 +0100, Pali Rohár wrote: > > It is possible that we receive spurious INTx interrupt. So add needed check > before calling generic_handle_irq() function. > > Signed-off-by: Pali Rohár > Reviewed-by: Marek Behún > Cc: stable@vger.kernel.org > --- > drivers/pci/controller/pci-aardvark.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c > index 362faddae935..e7089db11f79 100644 > --- a/drivers/pci/controller/pci-aardvark.c > +++ b/drivers/pci/controller/pci-aardvark.c > @@ -1106,7 +1106,10 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie) > PCIE_ISR1_REG); > > virq = irq_find_mapping(pcie->irq_domain, i); > - generic_handle_irq(virq); > + if (virq) > + generic_handle_irq(virq); > + else > + dev_err(&pcie->pdev->dev, "unexpected INT%c IRQ\n", (char)i+'A'); Please don't scream like this. This is the best way to get into a DoS situation if you interrupt rate is high enough. At least rate-limit it. M. -- Without deviation from the norm, progress is not possible.