[ATM]: avoid race conditions related to atm_devs list

Use semaphore to protect atm_devs list, as no one need access to it from
interrupt context.  Avoid race conditions between atm_dev_register(),
atm_dev_lookup() and atm_dev_deregister().  Fix double spin_unlock() bug.

Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
Signed-off-by: Chas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 2 deletions

diff --git a/net/atm/resources.h b/net/atm/resources.h
index 12910619dbb6..b7fb82a93b42 100644
--- a/net/atm/resources.h
+++ b/net/atm/resources.h
@@ -11,8 +11,7 @@
 
 
 extern struct list_head atm_devs;
-extern spinlock_t atm_dev_lock;
-
+extern struct semaphore atm_dev_mutex;
 
 int atm_dev_ioctl(unsigned int cmd, void __user *arg);