@@ -616,6 +616,7 @@ static void kobject_cleanup(struct kobject *kobj)
{
struct kobj_type *t = get_ktype(kobj);
const char *name = kobj->name;
+ struct kobject *parent = kobj->parent;
pr_debug("kobject: '%s' (%p): %s, parent %p\n",
kobject_name(kobj), kobj, __func__, kobj->parent);
@@ -632,6 +633,8 @@ static void kobject_cleanup(struct kobject *kobj)
kobject_uevent(kobj, KOBJ_REMOVE);
}
+ kobject_get(parent);
+
/* remove from sysfs if the caller did not do it */
if (kobj->state_in_sysfs) {
pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
@@ -645,6 +648,8 @@ static void kobject_cleanup(struct kobject *kobj)
t->release(kobj);
}
+ kobject_put(parent);
+
/* free name if we allocated it */
if (name) {
pr_debug("kobject: '%s': free name\n", name);
If the only remaining reference to a parent, is the one taken by the child (in kobject_add_internal()), then when the last reference to the child goes away, both child and its parents shall be released. However, currently the resources of parent get released first, followed by the child's resources: kobject_cleanup(child) .... kobject_del(child) .... kobject_put(child->parent) -> results in parent's release() ... child->kobj_type->release() -> Child's release() This is a problem because the child's release() method may still need to use parent resources or memory for its own cleanup. E.g. child may need parent pointer for dma_free_coherent() etc. Signed-off-by: Rajat Jain <rajatja@google.com> Signed-off-by: Rajat Jain <rajatxjain@gmail.com> --- resending after an email address that bounced. lib/kobject.c | 5 +++++ 1 file changed, 5 insertions(+)