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 3yjGX41Gk1zDrJy for ; Thu, 23 Nov 2017 21:58:27 +1100 (AEDT) Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vANAvvIg070004 for ; Thu, 23 Nov 2017 05:58:25 -0500 Received: from e06smtp15.uk.ibm.com (e06smtp15.uk.ibm.com [195.75.94.111]) by mx0a-001b2d01.pphosted.com with ESMTP id 2edvyn8a68-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 23 Nov 2017 05:58:24 -0500 Received: from localhost by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 23 Nov 2017 10:58:22 -0000 Subject: Re: [PATCH v3] cxl: Check if vphb exists before iterating over AFU devices To: Vaibhav Jain , linuxppc-dev@lists.ozlabs.org Cc: Andrew Donnellan , Christophe Lombard , Philippe Bergheaud , "Alastair D'Silva" , Michael Ellerman , stable@vger.kernel.org References: <20171123033857.13122-1-vaibhav@linux.vnet.ibm.com> From: Frederic Barrat Date: Thu, 23 Nov 2017 11:58:18 +0100 MIME-Version: 1.0 In-Reply-To: <20171123033857.13122-1-vaibhav@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Message-Id: <1d37c502-61fe-2df2-41d8-05cf46d45e47@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Le 23/11/2017 à 04:38, Vaibhav Jain a écrit : > During an eeh a kernel-oops is reported if no vPHB is allocated to the > AFU. This happens as during AFU init, an error in creation of vPHB is > a non-fatal error. Hence afu->phb should always be checked for NULL > before iterating over it for the virtual AFU pci devices. > > This patch fixes the kenel-oops by adding a NULL pointer check for > afu->phb before it is dereferenced. > > Fixes: 9e8df8a2196("cxl: EEH support") > Cc: stable@vger.kernel.org > Signed-off-by: Vaibhav Jain > --- Thanks. Acked-by: Frederic Barrat > Changelog: > > v3 -> Fixed a reverse NULL check [Fred] > > Resend -> Added the 'Fixes' info and marking the patch to stable tree [Mpe] > > v2 -> Added the vphb NULL check to cxl_vphb_error_detected() [Andrew] > --- > drivers/misc/cxl/pci.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c > index bb7fd3f4edab..19969ee86d6f 100644 > --- a/drivers/misc/cxl/pci.c > +++ b/drivers/misc/cxl/pci.c > @@ -2083,6 +2083,9 @@ static pci_ers_result_t cxl_vphb_error_detected(struct cxl_afu *afu, > /* There should only be one entry, but go through the list > * anyway > */ > + if (afu->phb == NULL) > + return result; > + > list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) { > if (!afu_dev->driver) > continue; > @@ -2124,8 +2127,7 @@ static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev, > * Tell the AFU drivers; but we don't care what they > * say, we're going away. > */ > - if (afu->phb != NULL) > - cxl_vphb_error_detected(afu, state); > + cxl_vphb_error_detected(afu, state); > } > return PCI_ERS_RESULT_DISCONNECT; > } > @@ -2265,6 +2267,9 @@ static pci_ers_result_t cxl_pci_slot_reset(struct pci_dev *pdev) > if (cxl_afu_select_best_mode(afu)) > goto err; > > + if (afu->phb == NULL) > + continue; > + > list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) { > /* Reset the device context. > * TODO: make this less disruptive > @@ -2327,6 +2332,9 @@ static void cxl_pci_resume(struct pci_dev *pdev) > for (i = 0; i < adapter->slices; i++) { > afu = adapter->afu[i]; > > + if (afu->phb == NULL) > + continue; > + > list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) { > if (afu_dev->driver && afu_dev->driver->err_handler && > afu_dev->driver->err_handler->resume) >