Subject: [PATCH -rt] Fix initialization of spinlock in irttp_dup()

From: Deepak Saxena <[email-masked]>
Date: Tue, 20 Mar 2007 12:22:33 -0700

This was found around the 2.6.10 timeframe when testing with the -rt patch
and I believe is still is an issue. irttp_dup() does a memcpy() of the tsap_cb 
structure causing the spinlock protecting various fields in the structure to be 
duped.  This works OK in the non-RT case but in the RT case we end up with two 
mutexes pointing to the same wait_list and leading to an OOPS. Fix is to simply
initialize the spinlock after the memcpy().

Signed-off-by: Deepak Saxena <[email-masked]>

diff --git a/net/irda/irttp.c b/net/irda/irttp.c
index a7486b3..df2b2f7 100644
--- a/net/irda/irttp.c
+++ b/net/irda/irttp.c
@@ -1441,6 +1441,7 @@ struct tsap_cb *irttp_dup(struct tsap_cb
 	}
 	/* Dup */
 	memcpy(new, orig, sizeof(struct tsap_cb));
+	spin_lock_init(&new->lock);
 
 	/* We don't need the old instance any more */
 	spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);

-- 
Deepak Saxena - [email-masked] - http://www.plexity.net

In the end, they will not say, "those were dark times,"  they will ask
"why were their poets silent?" - Bertolt Brecht