From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 3yhqBs15kWzDr4W for ; Thu, 23 Nov 2017 04:26:59 +1100 (AEDT) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vAMHNsiK003164 for ; Wed, 22 Nov 2017 12:26:56 -0500 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0b-001b2d01.pphosted.com with ESMTP id 2edbk2ya7w-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 22 Nov 2017 12:26:55 -0500 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 22 Nov 2017 17:26:53 -0000 Subject: Re: [RESEND][PATCH v2] cxl: Check if vphb exists before iterating over AFU devices To: Vaibhav Jain , linuxppc-dev@lists.ozlabs.org Cc: Philippe Bergheaud , stable@vger.kernel.org, "Alastair D'Silva" , Andrew Donnellan , Christophe Lombard References: <20171122121744.18697-1-vaibhav@linux.vnet.ibm.com> From: Frederic Barrat Date: Wed, 22 Nov 2017 18:26:48 +0100 MIME-Version: 1.0 In-Reply-To: <20171122121744.18697-1-vaibhav@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Message-Id: List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Le 22/11/2017 à 13:17, Vaibhav Jain a écrit : > During an eeh a kernel-oops is reported if no vPHB to allocated to the typo, "to allocated". Not important, but.... > 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 > --- > Changelog: > > 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..18773343ab3e 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; > + .. that one is more annoying. afu->phb == NULL? Fred > 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) >