Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759102Ab2EUVHj (ORCPT ); Mon, 21 May 2012 17:07:39 -0400 Received: from mga11.intel.com ([192.55.52.93]:54329 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756871Ab2EUVHi (ORCPT ); Mon, 21 May 2012 17:07:38 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="155344767" Subject: Re: [PATCH] x86: check for valid irq_cfg pointer in smp_irq_move_cleanup_interrupt From: Suresh Siddha Reply-To: Suresh Siddha To: Dimitri Sivanich Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Yinghai Lu , Naga Chumbalkar , Jacob Pan , linux-kernel@vger.kernel.org Date: Mon, 21 May 2012 14:05:53 -0700 In-Reply-To: <20120521164959.GE16454@sgi.com> References: <20120521164959.GE16454@sgi.com> Organization: Intel Corp Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.0.3 (3.0.3-1.fc15) Content-Transfer-Encoding: 7bit Message-ID: <1337634353.1997.144.camel@sbsiddha-desk.sc.intel.com> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1364 Lines: 41 On Mon, 2012-05-21 at 11:49 -0500, Dimitri Sivanich wrote: > The smp_irq_move_cleanup_interrupt routine should be checking for a valid > irq_cfg pointer prior to accessing it. It also seems that this should be > done after taking the desc lock. I think these changes are correct. Did you see any crashes during module unload etc? Reviewed-by: Suresh Siddha > > Signed-off-by: Dimitri Sivanich > --- > arch/x86/kernel/apic/io_apic.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > Index: linux/arch/x86/kernel/apic/io_apic.c > =================================================================== > --- linux.orig/arch/x86/kernel/apic/io_apic.c > +++ linux/arch/x86/kernel/apic/io_apic.c > @@ -2478,9 +2478,12 @@ asmlinkage void smp_irq_move_cleanup_int > if (!desc) > continue; > > - cfg = irq_cfg(irq); > raw_spin_lock(&desc->lock); > > + cfg = irq_cfg(irq); > + if (!cfg) > + goto unlock; > + > /* > * Check if the irq migration is in progress. If so, we > * haven't received the cleanup request yet for this irq. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/