From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935703AbcLMRQF (ORCPT ); Tue, 13 Dec 2016 12:16:05 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56848 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933546AbcLMRQC (ORCPT ); Tue, 13 Dec 2016 12:16:02 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pradipta Ghosh , Andrew Donnellan , Russell Currey , Michael Ellerman Subject: [PATCH 4.4 01/16] powerpc/eeh: Fix deadlock when PE frozen state cant be cleared Date: Tue, 13 Dec 2016 09:15:47 -0800 Message-Id: <20161213171519.044222027@linuxfoundation.org> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161213171518.862135257@linuxfoundation.org> References: <20161213171518.862135257@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Donnellan commit 409bf7f8a02ef88db5a0f2cdcf9489914f4b8508 upstream. 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") Signed-off-by: Andrew Donnellan Acked-by: Russell Currey Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/eeh_driver.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -612,8 +612,10 @@ static int eeh_reset_device(struct eeh_p /* 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,