rpmsg: fix name service endpoint leak

The name service endpoint wasn't destroyed, so fix it.

This is achieved by introducing an internal __rpmsg_destroy_ept
function which doesn't assume the given ept is bound to an rpmsg
channel (much like the existing __rpmsg_create_ept).

This is needed because the name service ept belongs to the rpmsg bus,
and is never bound with a specific rpdev.

Reported-by: Omar Ramirez Luna <omar.ramirez@ti.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mark Grosen <mgrosen@ti.com>
Cc: Suman Anna <s-anna@ti.com>
Cc: Fernando Guzman Lugo <fernando.lugo@ti.com>
Cc: Rob Clark <rob@ti.com>
Cc: Ludovic BARRE <ludovic.barre@stericsson.com>
Cc: Loic PALLARDY <loic.pallardy@stericsson.com>
Cc: Omar Ramirez Luna <omar.ramirez@ti.com>
diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
index 8980ac2..4db9cf8 100644
--- a/drivers/rpmsg/virtio_rpmsg_bus.c
+++ b/drivers/rpmsg/virtio_rpmsg_bus.c
@@ -290,6 +290,26 @@
 EXPORT_SYMBOL(rpmsg_create_ept);
 
 /**
+ * __rpmsg_destroy_ept() - destroy an existing rpmsg endpoint
+ * @vrp: virtproc which owns this ept
+ * @ept: endpoing to destroy
+ *
+ * An internal function which destroy an ept without assuming it is
+ * bound to an rpmsg channel. This is needed for handling the internal
+ * name service endpoint, which isn't bound to an rpmsg channel.
+ * See also __rpmsg_create_ept().
+ */
+static void
+__rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept)
+{
+	mutex_lock(&vrp->endpoints_lock);
+	idr_remove(&vrp->endpoints, ept->addr);
+	mutex_unlock(&vrp->endpoints_lock);
+
+	kfree(ept);
+}
+
+/**
  * rpmsg_destroy_ept() - destroy an existing rpmsg endpoint
  * @ept: endpoing to destroy
  *
@@ -298,13 +318,7 @@
  */
 void rpmsg_destroy_ept(struct rpmsg_endpoint *ept)
 {
-	struct virtproc_info *vrp = ept->rpdev->vrp;
-
-	mutex_lock(&vrp->endpoints_lock);
-	idr_remove(&vrp->endpoints, ept->addr);
-	mutex_unlock(&vrp->endpoints_lock);
-
-	kfree(ept);
+	__rpmsg_destroy_ept(ept->rpdev->vrp, ept);
 }
 EXPORT_SYMBOL(rpmsg_destroy_ept);
 
@@ -964,6 +978,9 @@
 	if (ret)
 		dev_warn(&vdev->dev, "can't remove rpmsg device: %d\n", ret);
 
+	if (vrp->ns_ept)
+		__rpmsg_destroy_ept(vrp, vrp->ns_ept);
+
 	idr_remove_all(&vrp->endpoints);
 	idr_destroy(&vrp->endpoints);