net: mvpp2: debugfs: fix memory leak when using debugfs_lookup()

commit 3ce48957b1db2ec8d8385878f70f88c3461712d1 upstream.

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  Fix this up to be much
simpler logic and only create the root debugfs directory once when the
driver is first accessed.  That resolves the memory leak and makes
things more obvious as to what the intent is.

Cc: Marcin Wojtas <mw@semihalf.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
Cc: stable <stable@kernel.org>
Fixes: 39d7629f2ab8 ("net: mvpp2: add a debugfs interface for the Header Parser")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c
index 4a3baa7e0142416d7ca15d9677362c9c29e5b986..0eec05d905eb0fc893d8cb64087beddfb4cbdc1e 100644 (file)
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c
@@ -700,10 +700,10 @@ void mvpp2_dbgfs_cleanup(struct mvpp2 *priv)
 
 void mvpp2_dbgfs_init(struct mvpp2 *priv, const char *name)
 {
-       struct dentry *mvpp2_dir, *mvpp2_root;
+       static struct dentry *mvpp2_root;
+       struct dentry *mvpp2_dir;
        int ret, i;
 
-       mvpp2_root = debugfs_lookup(MVPP2_DRIVER_NAME, NULL);
        if (!mvpp2_root)
                mvpp2_root = debugfs_create_dir(MVPP2_DRIVER_NAME, NULL);