commit 7162a3e0db34e914a8bc5bf74bbae0b386310cf8
author Roland Dreier <rolandd@cisco.com> Sun Oct 30 09:50:04 2005 -0800
committer Roland Dreier <rolandd@cisco.com> Mon Oct 31 07:10:32 2005 -0800
tree ffd7eba03f29dd2932dd32ac4adc2921bde7644b
parent a20583a7c2e35d80b1dfc1f60c9729498838725e

[IB] uverbs: Avoid NULL pointer deref on CQ async event

Userspace CQs that have no completion event channel attached end up
with their cq_context set to NULL.  However, asynchronous events like
"CQ overrun" can still occur on such CQs, so add a uverbs_file member
to struct ib_ucq_object that we can follow to deliver these events.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/core/uverbs_main.c

diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 0eb38f4..e58a7b2 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -442,13 +442,10 @@
 
 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
 {
-	struct ib_uverbs_event_file *ev_file = context_ptr;
-	struct ib_ucq_object *uobj;
+	struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
+						  struct ib_ucq_object, uobject);
 
-	uobj = container_of(event->element.cq->uobject,
-			    struct ib_ucq_object, uobject);
-
-	ib_uverbs_async_handler(ev_file->uverbs_file, uobj->uobject.user_handle,
+	ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
 				event->event, &uobj->async_list,
 				&uobj->async_events_reported);