On Sat, 2012-11-10 at 21:57 +0800, Jiang Liu wrote:
> From: Jiang Liu <jiang.liu@xxxxxxxxxx>
>
> 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 <jiang.liu@xxxxxxxxxx>
> ---
> drivers/vfio/vfio.c | 31 +++++++++++++++----------------
> 1 file changed, 15 insertions(+), 16 deletions(-)
This patch and patch 6/6 looks like good vfio fixes regardless of how we
tackle the driver binding problem. Please submit them separately.
Thanks for the patches, I look forward to a solution here. Thanks,
Alex
>
> 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)
--
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