[PATCH] SELinux: change isec semaphore to a mutex

This patch converts the remaining isec->sem into a mutex.  Very similar
locking is provided as before only in the faster smaller mutex rather than a
semaphore.  An out_unlock path is introduced rather than the conditional
unlocking found in the original code.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

security/selinux/ss/services.c

@@ -2578,7 +2578,7 @@ int selinux_netlbl_inode_permission(struct inode *inode, int mask)
 	sock = SOCKET_I(inode);
 	isec = inode->i_security;
 	sksec = sock->sk->sk_security;
-	down(&isec->sem);
+	mutex_lock(&isec->lock);
 	if (unlikely(sksec->nlbl_state == NLBL_REQUIRE &&
 		     (mask & (MAY_WRITE | MAY_APPEND)))) {
 		lock_sock(sock->sk);
@@ -2586,7 +2586,7 @@ int selinux_netlbl_inode_permission(struct inode *inode, int mask)
 		release_sock(sock->sk);
 	} else
 		rc = 0;
-	up(&isec->sem);
+	mutex_unlock(&isec->lock);
 
 	return rc;
 }