rpdev->id.name);
}
+/**
+ * __ept_release() - deallocate an rpmsg endpoint
+ * @kref: the ept's reference count
+ *
+ * This function deallocates an ept, and is invoked when its @kref refcount
+ * drops to zero.
+ *
+ * Never invoke this function directly!
+ */
+static void __ept_release(struct kref *kref)
+{
+ struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint,
+ refcount);
+ /*
+ * At this point no one holds a reference to ept anymore,
+ * so we can directly free it
+ */
+ kfree(ept);
+}
+
/* for more info, see below documentation of rpmsg_create_ept() */
static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp,
struct rpmsg_channel *rpdev, rpmsg_rx_cb_t cb,
return NULL;
}
+ kref_init(&ept->refcount);
+ mutex_init(&ept->cb_lock);
+
ept->rpdev = rpdev;
ept->cb = cb;
ept->priv = priv;
idr_remove(&vrp->endpoints, request);
free_ept:
mutex_unlock(&vrp->endpoints_lock);
- kfree(ept);
+ kref_put(&ept->refcount, __ept_release);
return NULL;
}
static void
__rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept)
{
+ /* make sure new inbound messages can't find this ept anymore */
mutex_lock(&vrp->endpoints_lock);
idr_remove(&vrp->endpoints, ept->addr);
mutex_unlock(&vrp->endpoints_lock);
- kfree(ept);
+ /* make sure in-flight inbound messages won't invoke cb anymore */
+ mutex_lock(&ept->cb_lock);
+ ept->cb = NULL;
+ mutex_unlock(&ept->cb_lock);
+
+ kref_put(&ept->refcount, __ept_release);
}
/**
/* use the dst addr to fetch the callback of the appropriate user */
mutex_lock(&vrp->endpoints_lock);
+
ept = idr_find(&vrp->endpoints, msg->dst);
+
+ /* let's make sure no one deallocates ept while we use it */
+ if (ept)
+ kref_get(&ept->refcount);
+
mutex_unlock(&vrp->endpoints_lock);
- if (ept && ept->cb)
- ept->cb(ept->rpdev, msg->data, msg->len, ept->priv, msg->src);
- else
+ if (ept) {
+ /* make sure ept->cb doesn't go away while we use it */
+ mutex_lock(&ept->cb_lock);
+
+ if (ept->cb)
+ ept->cb(ept->rpdev, msg->data, msg->len, ept->priv,
+ msg->src);
+
+ mutex_unlock(&ept->cb_lock);
+
+ /* farewell, ept, we don't need you anymore */
+ kref_put(&ept->refcount, __ept_release);
+ } else
dev_warn(dev, "msg received with no recepient\n");
/* publish the real size of the buffer */
return ret;
}
-module_init(rpmsg_init);
+subsys_initcall(rpmsg_init);
static void __exit rpmsg_fini(void)
{