netdev - [PATCH] Revert "net: mvpp2: debugfs: fix memory leak when using debugfs

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Date:   Fri, 23 Sep 2022 19:47:36 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     unlisted-recipients:; (no To-header on input)
Cc:     Sasha Levin <sashal@...nel.org>, Marcin Wojtas <mw@...ihalf.com>,
        Russell King <linux@...linux.org.uk>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        netdev@...r.kernel.org, stable@...nel.org
Subject: [PATCH] Revert "net: mvpp2: debugfs: fix memory leak when using debugfs_lookup()"

This reverts commit fe2c9c61f668cde28dac2b188028c5299cedcc1e.

On Tue, Sep 13, 2022 at 05:48:58PM +0100, Russell King (Oracle) wrote:
>What happens if this is built as a module, and the module is loaded,
>binds (and creates the directory), then is removed, and then re-
>inserted?  Nothing removes the old directory, so doesn't
>debugfs_create_dir() fail, resulting in subsequent failure to add
>any subsequent debugfs entries?
>
>I don't think this patch should be backported to stable trees until
>this point is addressed.

Revert until a proper fix is available as the original behavior was
better.

Cc: Marcin Wojtas <mw@...ihalf.com>
Cc: Russell King <linux@...linux.org.uk>
Cc: "David S. Miller" <davem@...emloft.net>
Cc: Eric Dumazet <edumazet@...gle.com>
Cc: Jakub Kicinski <kuba@...nel.org>
Cc: Paolo Abeni <pabeni@...hat.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: netdev@...r.kernel.org
Cc: stable@...nel.org
Reported-by: Russell King <linux@...linux.org.uk>
Fixes: fe2c9c61f668 ("net: mvpp2: debugfs: fix memory leak when using debugfs_lookup()")
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c
index 0eec05d905eb..4a3baa7e0142 100644
--- 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)
 {
-	static struct dentry *mvpp2_root;
-	struct dentry *mvpp2_dir;
+	struct dentry *mvpp2_dir, *mvpp2_root;
 	int ret, i;
 
+	mvpp2_root = debugfs_lookup(MVPP2_DRIVER_NAME, NULL);
 	if (!mvpp2_root)
 		mvpp2_root = debugfs_create_dir(MVPP2_DRIVER_NAME, NULL);
 
-- 
2.35.1