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authorJason Gunthorpe <jgg@nvidia.com>2021-04-06 16:40:30 -0300
committerAlex Williamson <alex.williamson@redhat.com>2021-04-07 15:39:17 -0600
commit9a302449a58d45d0ef2aab686f64b35919bc604c (patch)
treef7716b02c40a3a9e58634786baee6ec67f6531dc /drivers/vfio
parenta9f8111d0b5f445d853345e6917c1781573e4ba9 (diff)
vfio/mdev: Add missing reference counting to mdev_type
struct mdev_type holds a pointer to the kref'd object struct mdev_parent, but doesn't hold the kref. The lifetime of the parent becomes implicit because parent_remove_sysfs_files() is supposed to remove all the access before the parent can be freed, but this is very hard to reason about. Make it obviously correct by adding the missing get. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <7-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
-rw-r--r--drivers/vfio/mdev/mdev_sysfs.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
index bcfe48d56e8a..8c169d12ba7d 100644
--- a/drivers/vfio/mdev/mdev_sysfs.c
+++ b/drivers/vfio/mdev/mdev_sysfs.c
@@ -81,6 +81,8 @@ static void mdev_type_release(struct kobject *kobj)
struct mdev_type *type = to_mdev_type(kobj);
pr_debug("Releasing group %s\n", kobj->name);
+ /* Pairs with the get in add_mdev_supported_type() */
+ mdev_put_parent(type->parent);
kfree(type);
}
@@ -106,6 +108,8 @@ static struct mdev_type *add_mdev_supported_type(struct mdev_parent *parent,
type->kobj.kset = parent->mdev_types_kset;
type->parent = parent;
+ /* Pairs with the put in mdev_type_release() */
+ mdev_get_parent(parent);
ret = kobject_init_and_add(&type->kobj, &mdev_type_ktype, NULL,
"%s-%s", dev_driver_string(parent->dev),