From fd60ae404f104f12369e654af9cf03b1f1047661 Mon Sep 17 00:00:00 2001
From: Jack Morgenstein <jackm@mellanox.co.il>
Date: Thu, 3 Aug 2006 10:56:42 -0700
Subject: IB/uverbs: Avoid a crash on device hot remove

Wait until all users have closed their device context before allowing
device unregistration to complete.  This prevents a crash caused by
referring to stale data structures.

A better solution would be to have a way to revoke contexts rather
than waiting for userspace to close the context, but that's a much
bigger change that will have to wait.  For now let's at least avoid
the crash.

Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
---
 drivers/infiniband/core/uverbs.h | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'drivers/infiniband/core/uverbs.h')

diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h
index bb9bee56a824..102a59c033ff 100644
--- a/drivers/infiniband/core/uverbs.h
+++ b/drivers/infiniband/core/uverbs.h
@@ -42,6 +42,7 @@
 #include <linux/kref.h>
 #include <linux/idr.h>
 #include <linux/mutex.h>
+#include <linux/completion.h>
 
 #include <rdma/ib_verbs.h>
 #include <rdma/ib_user_verbs.h>
@@ -69,6 +70,7 @@
 
 struct ib_uverbs_device {
 	struct kref				ref;
+	struct completion			comp;
 	int					devnum;
 	struct cdev			       *dev;
 	struct class_device		       *class_dev;
-- 
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