From: Ursula Braun <braunu@de.ibm.com>
Date: Fri, 8 Feb 2008 02:06:52 +0000 (-0800)
Subject: [IUCV]: wrong irq-disabling locking at module load time
X-Git-Tag: v2.6.25-rc1~45^2~11
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=435bc9dfc6927eed9465e297d7aca1217aa61956;p=linux-2.6

[IUCV]: wrong irq-disabling locking at module load time

Linux may hang when running af_iucv socket programs concurrently
with a load of module netiucv. iucv_register() tries to take the
iucv_table_lock with spin_lock_irq. This conflicts with
iucv_connect() which has a need for an smp_call_function while
holding the iucv_table_lock.
Solution: use bh-disabling locking in iucv_register()

Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c
index f13fe8821c..2753b0c448 100644
--- a/net/iucv/iucv.c
+++ b/net/iucv/iucv.c
@@ -693,9 +693,9 @@ int iucv_register(struct iucv_handler *handler, int smp)
 		iucv_setmask_up();
 	INIT_LIST_HEAD(&handler->paths);
 
-	spin_lock_irq(&iucv_table_lock);
+	spin_lock_bh(&iucv_table_lock);
 	list_add_tail(&handler->list, &iucv_handler_list);
-	spin_unlock_irq(&iucv_table_lock);
+	spin_unlock_bh(&iucv_table_lock);
 	rc = 0;
 out_mutex:
 	mutex_unlock(&iucv_register_mutex);