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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 B04B2C10DCE for ; Sun, 8 Mar 2020 10:15:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D13F206D7 for ; Sun, 8 Mar 2020 10:15:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726496AbgCHKO7 (ORCPT ); Sun, 8 Mar 2020 06:14:59 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:56465 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726210AbgCHKOe (ORCPT ); Sun, 8 Mar 2020 06:14:34 -0400 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jAsx6-0004na-1P; Sun, 08 Mar 2020 11:14:32 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id B1F5F1C2211; Sun, 8 Mar 2020 11:14:29 +0100 (CET) Date: Sun, 08 Mar 2020 10:14:29 -0000 From: "tip-bot2 for Thomas Gleixner" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: irq/core] genirq: Sanitize state handling in check_irq_resend() Cc: Thomas Gleixner , Marc Zyngier , x86 , LKML In-Reply-To: <20200306130623.882129117@linutronix.de> References: <20200306130623.882129117@linutronix.de> MIME-Version: 1.0 Message-ID: <158366246945.28353.16966446675179068982.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the irq/core branch of tip: Commit-ID: da90921acc62c71d27729ae211ccfda5370bf75b Gitweb: https://git.kernel.org/tip/da90921acc62c71d27729ae211ccfda5370bf75b Author: Thomas Gleixner AuthorDate: Fri, 06 Mar 2020 14:03:46 +01:00 Committer: Thomas Gleixner CommitterDate: Sun, 08 Mar 2020 11:06:41 +01:00 genirq: Sanitize state handling in check_irq_resend() The code sets IRQS_REPLAY unconditionally whether the resend happens or not. That doesn't have bad side effects right now, but inconsistent state is always a latent source of problems. Signed-off-by: Thomas Gleixner Acked-by: Marc Zyngier Link: https://lkml.kernel.org/r/20200306130623.882129117@linutronix.de --- kernel/irq/resend.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c index a21fc4e..bef72dc 100644 --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -93,6 +93,8 @@ static int irq_sw_resend(struct irq_desc *desc) */ int check_irq_resend(struct irq_desc *desc) { + int err = 0; + /* * We do not resend level type interrupts. Level type interrupts * are resent by hardware when they are still active. Clear the @@ -106,13 +108,17 @@ int check_irq_resend(struct irq_desc *desc) if (desc->istate & IRQS_REPLAY) return -EBUSY; - if (desc->istate & IRQS_PENDING) { - desc->istate &= ~IRQS_PENDING; - desc->istate |= IRQS_REPLAY; + if (!(desc->istate & IRQS_PENDING)) + return 0; - if (!desc->irq_data.chip->irq_retrigger || - !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) - return irq_sw_resend(desc); - } - return 0; + desc->istate &= ~IRQS_PENDING; + + if (!desc->irq_data.chip->irq_retrigger || + !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) + err = irq_sw_resend(desc); + + /* If the retrigger was successfull, mark it with the REPLAY bit */ + if (!err) + desc->istate |= IRQS_REPLAY; + return err; }