From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754355Ab3B1Ope (ORCPT ); Thu, 28 Feb 2013 09:45:34 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:41838 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754264Ab3B1Op2 (ORCPT ); Thu, 28 Feb 2013 09:45:28 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "Wang, Song-Bo (Stoney)" , Thomas Gleixner , Luis Henriques Subject: [PATCH 001/139] genirq: Avoid deadlock in spurious handling Date: Thu, 28 Feb 2013 14:42:31 +0000 Message-Id: <1362062689-2567-2-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1362062689-2567-1-git-send-email-luis.henriques@canonical.com> References: <1362062689-2567-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.7 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit e716efde75267eab919cdb2bef5b2cb77f305326 upstream. commit 52553ddf(genirq: fix regression in irqfixup, irqpoll) introduced a potential deadlock by calling the action handler with the irq descriptor lock held. Remove the call and let the handling code run even for an interrupt where only a single action is registered. That matches the goal of the above commit and avoids the deadlock. Document the confusing action = desc->action reload in the handling loop while at it. Reported-and-tested-by: "Wang, Warner" Tested-by: Edward Donovan Cc: "Wang, Song-Bo (Stoney)" Signed-off-by: Thomas Gleixner Signed-off-by: Luis Henriques --- kernel/irq/spurious.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 611cd60..7b5f012 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -80,13 +80,11 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force) /* * All handlers must agree on IRQF_SHARED, so we test just the - * first. Check for action->next as well. + * first. */ action = desc->action; if (!action || !(action->flags & IRQF_SHARED) || - (action->flags & __IRQF_TIMER) || - (action->handler(irq, action->dev_id) == IRQ_HANDLED) || - !action->next) + (action->flags & __IRQF_TIMER)) goto out; /* Already running on another processor */ @@ -104,6 +102,7 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force) do { if (handle_irq_event(desc) == IRQ_HANDLED) ret = IRQ_HANDLED; + /* Make sure that there is still a valid action */ action = desc->action; } while ((desc->istate & IRQS_PENDING) && action); desc->istate &= ~IRQS_POLL_INPROGRESS; -- 1.8.1.2