From mboxrd@z Thu Jan  1 00:00:00 1970
From: Krzysztof Halasa <khc@pm.waw.pl>
Subject: [PATCH] WAN: protect HDLC proto list while insmod/rmmod
Date: Mon, 19 May 2008 19:00:51 +0200
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In-Reply-To: <m3lk2djbq3.fsf@maximus.localdomain> (Krzysztof Halasa's message of "Wed\, 14 May 2008 14\:45\:24 +0200")
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WAN: protect protocol list in hdlc.c with RTNL.
   =20
Signed-off-by: Krzysztof Ha=B3asa <khc@pm.waw.pl>

--- a/drivers/net/wan/hdlc.c
+++ b/drivers/net/wan/hdlc.c
@@ -42,8 +42,7 @@ static const char* version =3D "HDLC support module r=
evision 1.22";
=20
 #undef DEBUG_LINK
=20
-static struct hdlc_proto *first_proto =3D NULL;
-
+static struct hdlc_proto *first_proto;
=20
 static int hdlc_change_mtu(struct net_device *dev, int new_mtu)
 {
@@ -313,21 +312,25 @@ void detach_hdlc_protocol(struct net_device *dev)
=20
 void register_hdlc_protocol(struct hdlc_proto *proto)
 {
+	rtnl_lock();
 	proto->next =3D first_proto;
 	first_proto =3D proto;
+	rtnl_unlock();
 }
=20
=20
 void unregister_hdlc_protocol(struct hdlc_proto *proto)
 {
-	struct hdlc_proto **p =3D &first_proto;
-	while (*p) {
-		if (*p =3D=3D proto) {
-			*p =3D proto->next;
-			return;
-		}
+	struct hdlc_proto **p;
+
+	rtnl_lock();
+	p =3D &first_proto;
+	while (*p !=3D proto) {
+		BUG_ON(!*p);
 		p =3D &((*p)->next);
 	}
+	*p =3D proto->next;
+	rtnl_unlock();
 }
=20
=20