From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751904Ab2KJN70 (ORCPT ); Sat, 10 Nov 2012 08:59:26 -0500 Received: from mail-da0-f46.google.com ([209.85.210.46]:47743 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751638Ab2KJN7W (ORCPT ); Sat, 10 Nov 2012 08:59:22 -0500 From: Jiang Liu To: Alex Williamson , Greg Kroah-Hartman Cc: Jiang Liu , Joerg Roedel , Yinghai Lu , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Hanjun Guo Subject: [RFC PATCH 3/6] VFIO: unregister IOMMU notifier on error recovery path Date: Sat, 10 Nov 2012 21:57:16 +0800 Message-Id: <1352555839-18961-3-git-send-email-jiang.liu@huawei.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1352555839-18961-1-git-send-email-jiang.liu@huawei.com> References: <1352555839-18961-1-git-send-email-jiang.liu@huawei.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiang Liu On error recovery path in function vfio_create_group(), it should unregister the IOMMU notifier for the new VFIO group. Otherwise it may cause invalid memory access later when handling bus notifications. Signed-off-by: Jiang Liu --- drivers/vfio/vfio.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 17830c9..3359ec2 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -191,6 +191,17 @@ static void vfio_container_put(struct vfio_container *container) kref_put(&container->kref, vfio_container_release); } +static void vfio_group_unlock_and_free(struct vfio_group *group) +{ + mutex_unlock(&vfio.group_lock); + /* + * Unregister outside of lock. A spurious callback is harmless now + * that the group is no longer in vfio.group_list. + */ + iommu_group_unregister_notifier(group->iommu_group, &group->nb); + kfree(group); +} + /** * Group objects - create, release, get, put, search */ @@ -229,8 +240,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group) minor = vfio_alloc_group_minor(group); if (minor < 0) { - mutex_unlock(&vfio.group_lock); - kfree(group); + vfio_group_unlock_and_free(group); return ERR_PTR(minor); } @@ -239,8 +249,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group) if (tmp->iommu_group == iommu_group) { vfio_group_get(tmp); vfio_free_group_minor(minor); - mutex_unlock(&vfio.group_lock); - kfree(group); + vfio_group_unlock_and_free(group); return tmp; } } @@ -249,8 +258,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group) group, "%d", iommu_group_id(iommu_group)); if (IS_ERR(dev)) { vfio_free_group_minor(minor); - mutex_unlock(&vfio.group_lock); - kfree(group); + vfio_group_unlock_and_free(group); return (struct vfio_group *)dev; /* ERR_PTR */ } @@ -274,16 +282,7 @@ static void vfio_group_release(struct kref *kref) device_destroy(vfio.class, MKDEV(MAJOR(vfio.devt), group->minor)); list_del(&group->vfio_next); vfio_free_group_minor(group->minor); - - mutex_unlock(&vfio.group_lock); - - /* - * Unregister outside of lock. A spurious callback is harmless now - * that the group is no longer in vfio.group_list. - */ - iommu_group_unregister_notifier(group->iommu_group, &group->nb); - - kfree(group); + vfio_group_unlock_and_free(group); } static void vfio_group_put(struct vfio_group *group) -- 1.7.9.5