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[209.132.180.67]) by mx.google.com with ESMTP id w12-v6si2135682pld.367.2018.06.13.00.50.13; Wed, 13 Jun 2018 00:50:27 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754526AbeFMHsg (ORCPT + 99 others); Wed, 13 Jun 2018 03:48:36 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:41874 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S934508AbeFMHsS (ORCPT ); Wed, 13 Jun 2018 03:48:18 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D78E4407049F; Wed, 13 Jun 2018 07:48:17 +0000 (UTC) Received: from gondolin (dhcp-192-215.str.redhat.com [10.33.192.215]) by smtp.corp.redhat.com (Postfix) with ESMTP id 93E4520345E2; Wed, 13 Jun 2018 07:48:14 +0000 (UTC) Date: Wed, 13 Jun 2018 09:48:12 +0200 From: Cornelia Huck To: Pierre Morel Cc: Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.com, kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com, alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com Subject: Re: [PATCH v5 04/13] s390: vfio-ap: base implementation of VFIO AP device driver Message-ID: <20180613094812.1fd1846d.cohuck@redhat.com> In-Reply-To: <889b8d41-e08c-0eb5-2de0-a1d6669a03b3@linux.ibm.com> References: <1525705912-12815-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1525705912-12815-5-git-send-email-akrowiak@linux.vnet.ibm.com> <889b8d41-e08c-0eb5-2de0-a1d6669a03b3@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Wed, 13 Jun 2018 07:48:18 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Wed, 13 Jun 2018 07:48:18 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'cohuck@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 13 Jun 2018 09:41:16 +0200 Pierre Morel wrote: > On 07/05/2018 17:11, Tony Krowiak wrote: > > Introduces a new AP device driver. This device driver > > is built on the VFIO mediated device framework. The framework > > provides sysfs interfaces that facilitate passthrough > > access by guests to devices installed on the linux host. > ...snip... > > > +static int vfio_ap_matrix_dev_create(void) > > +{ > > + int ret; > > + > > + vfio_ap_root_device = root_device_register(VFIO_AP_ROOT_NAME); > > + > > + if (IS_ERR(vfio_ap_root_device)) { > > + ret = PTR_ERR(vfio_ap_root_device); > > + goto done; > > + } > > + > > + ap_matrix = kzalloc(sizeof(*ap_matrix), GFP_KERNEL); > > + if (!ap_matrix) { > > + ret = -ENOMEM; > > + goto matrix_alloc_err; > > + } > > + > > + ap_matrix->device.type = &vfio_ap_dev_type; > > + dev_set_name(&ap_matrix->device, "%s", VFIO_AP_DEV_NAME); > > + ap_matrix->device.parent = vfio_ap_root_device; > > + ap_matrix->device.release = vfio_ap_matrix_dev_release; > > + ap_matrix->device.driver = &vfio_ap_drv.driver; > > + > > + ret = device_register(&ap_matrix->device); > > + if (ret) > > + goto matrix_reg_err; > > + > > + goto done; > > + > > +matrix_reg_err: > > + put_device(&ap_matrix->device); > > Did not see this before but here you certainly want to > do a kfree and not a put_device. No, this must not be a kfree. Once you've tried to register something embedding a struct device with the driver core, you need to use put_device, as another path may have acquired a reference, even if registering ultimately failed. See the comment for device_register(). IOW, the code is correct. > > > > > + > > +matrix_alloc_err: > > + root_device_unregister(vfio_ap_root_device); > > + > > +done: > > + return ret; > > +} > > + > > +static void vfio_ap_matrix_dev_destroy(struct ap_matrix *ap_matrix) > > +{ > > + device_unregister(&ap_matrix->device); > > + root_device_unregister(vfio_ap_root_device); > > Also here you need a kfree(ap_matrix) too . Same here.