From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3tTdL14jGdzDvvX for ; Thu, 1 Dec 2016 11:23:21 +1100 (AEDT) Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id uB10IfH6010250 for ; Wed, 30 Nov 2016 19:23:19 -0500 Received: from e23smtp07.au.ibm.com (e23smtp07.au.ibm.com [202.81.31.140]) by mx0a-001b2d01.pphosted.com with ESMTP id 2724mx457t-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 30 Nov 2016 19:23:18 -0500 Received: from localhost by e23smtp07.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 1 Dec 2016 10:23:16 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id D1C2E3578056 for ; Thu, 1 Dec 2016 11:23:14 +1100 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id uB10NE7C56754382 for ; Thu, 1 Dec 2016 11:23:14 +1100 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id uB10NE8s029753 for ; Thu, 1 Dec 2016 11:23:14 +1100 From: Andrew Donnellan To: linuxppc-dev@lists.ozlabs.org, ruscur@russell.cc, gwshan@linux.vnet.ibm.com Cc: ukrishn@linux.vnet.ibm.com, pradghos@in.ibm.com Subject: [PATCH] powerpc/eeh: fix deadlock when PE frozen state can't be cleared Date: Thu, 1 Dec 2016 11:23:05 +1100 Message-Id: <20161201002305.14591-1-andrew.donnellan@au1.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , In eeh_reset_device(), we take the pci_rescan_remove_lock immediately after after we call eeh_reset_pe() to reset the PCI controller. We then call eeh_clear_pe_frozen_state(), which can return an error. In this case, we bail out of eeh_reset_device() without calling pci_unlock_rescan_remove(). Add a call to pci_unlock_rescan_remove() in the eeh_clear_pe_frozen_state() error path so that we don't cause a deadlock later on. Reported-by: Pradipta Ghosh Fixes: 78954700631f ("powerpc/eeh: Avoid I/O access during PE reset") Cc: stable@vger.kernel.org Signed-off-by: Andrew Donnellan --- arch/powerpc/kernel/eeh_driver.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index a62be72..5c31369 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -671,8 +671,10 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus, /* Clear frozen state */ rc = eeh_clear_pe_frozen_state(pe, false); - if (rc) + if (rc) { + pci_unlock_rescan_remove(); return rc; + } /* Give the system 5 seconds to finish running the user-space * hotplug shutdown scripts, e.g. ifdown for ethernet. Yes, -- Andrew Donnellan OzLabs, ADL Canberra andrew.donnellan@au1.ibm.com IBM Australia Limited