From 7e76e13576fd2dad4614577e0945081a03e846df Mon Sep 17 00:00:00 2001 From: "Russell King (Oracle)" Date: Mon, 3 Oct 2022 17:19:27 +0100 Subject: [PATCH] net: mvpp2: fix mvpp2 debugfs leak [ Upstream commit 05dabc8cb63e3892361605016fa2248efd1277ae ] When mvpp2 is unloaded, the driver specific debugfs directory is not removed, which technically leads to a memory leak. However, this directory is only created when the first device is probed, so the hardware is present. Removing the module is only something a developer would to when e.g. testing out changes, so the module would be reloaded. So this memory leak is minor. The original attempt in commit 5f23e1396e1f ("net: mvpp2: debugfs: fix memory leak when using debugfs_lookup()") that was labelled as a memory leak fix was not, it fixed a refcount leak, but in doing so created a problem when the module is reloaded - the directory already exists, but mvpp2_root is NULL, so we lose all debugfs entries. This fix has been reverted. This is the alternative fix, where we remove the offending directory whenever the driver is unloaded. Fixes: a8fd6ab05737 ("net: mvpp2: add a debugfs interface for the Header Parser") Signed-off-by: Russell King (Oracle) Reviewed-by: Greg Kroah-Hartman Reviewed-by: Marcin Wojtas Link: https://lore.kernel.org/r/E1ofOAB-00CzkG-UO@rmk-PC.armlinux.org.uk Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/marvell/mvpp2/mvpp2.h | 1 + drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c | 10 ++++++++-- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 13 ++++++++++++- 3 files changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h index 543a310ec1029..cf45b9210c155 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h @@ -1202,5 +1202,6 @@ u32 mvpp2_read(struct mvpp2 *priv, u32 offset); void mvpp2_dbgfs_init(struct mvpp2 *priv, const char *name); void mvpp2_dbgfs_cleanup(struct mvpp2 *priv); +void mvpp2_dbgfs_exit(void); #endif diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c index 4a3baa7e01424..75e83ea2a926e 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c @@ -691,6 +691,13 @@ static int mvpp2_dbgfs_port_init(struct dentry *parent, return 0; } +static struct dentry *mvpp2_root; + +void mvpp2_dbgfs_exit(void) +{ + debugfs_remove(mvpp2_root); +} + void mvpp2_dbgfs_cleanup(struct mvpp2 *priv) { debugfs_remove_recursive(priv->dbgfs_dir); @@ -700,10 +707,9 @@ void mvpp2_dbgfs_cleanup(struct mvpp2 *priv) void mvpp2_dbgfs_init(struct mvpp2 *priv, const char *name) { - struct dentry *mvpp2_dir, *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); diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index d700f1b5a4bf7..31dde6fbdbdca 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -6004,7 +6004,18 @@ static struct platform_driver mvpp2_driver = { }, }; -module_platform_driver(mvpp2_driver); +static int __init mvpp2_driver_init(void) +{ + return platform_driver_register(&mvpp2_driver); +} +module_init(mvpp2_driver_init); + +static void __exit mvpp2_driver_exit(void) +{ + platform_driver_unregister(&mvpp2_driver); + mvpp2_dbgfs_exit(); +} +module_exit(mvpp2_driver_exit); MODULE_DESCRIPTION("Marvell PPv2 Ethernet Driver - www.marvell.com"); MODULE_AUTHOR("Marcin Wojtas "); -- 2.39.5