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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Kalle Valo <kvalo@codeaurora.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.12 187/296] libertas: register sysfs groups properly
Date:   Mon, 31 May 2021 15:14:02 +0200
Message-Id: <20210531130710.159096271@linuxfoundation.org>
In-Reply-To: <20210531130703.762129381@linuxfoundation.org>
References: <20210531130703.762129381@linuxfoundation.org>
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 7e79b38fe9a403b065ac5915465f620a8fb3de84 ]

The libertas driver was trying to register sysfs groups "by hand" which
causes them to be created _after_ the device is initialized and
announced to userspace, which causes races and can prevent userspace
tools from seeing the sysfs files correctly.

Fix this up by using the built-in sysfs_groups pointers in struct
net_device which were created for this very reason, fixing the race
condition, and properly allowing for any error that might have occured
to be handled properly.

Cc: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-54-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/marvell/libertas/mesh.c | 28 +++-----------------
 1 file changed, 4 insertions(+), 24 deletions(-)

diff --git a/drivers/net/wireless/marvell/libertas/mesh.c b/drivers/net/wireless/marvell/libertas/mesh.c
index c611e6668b21..c68814841583 100644
--- a/drivers/net/wireless/marvell/libertas/mesh.c
+++ b/drivers/net/wireless/marvell/libertas/mesh.c
@@ -801,19 +801,6 @@ static const struct attribute_group mesh_ie_group = {
 	.attrs = mesh_ie_attrs,
 };
 
-static void lbs_persist_config_init(struct net_device *dev)
-{
-	int ret;
-	ret = sysfs_create_group(&(dev->dev.kobj), &boot_opts_group);
-	ret = sysfs_create_group(&(dev->dev.kobj), &mesh_ie_group);
-}
-
-static void lbs_persist_config_remove(struct net_device *dev)
-{
-	sysfs_remove_group(&(dev->dev.kobj), &boot_opts_group);
-	sysfs_remove_group(&(dev->dev.kobj), &mesh_ie_group);
-}
-
 
 /***************************************************************************
  * Initializing and starting, stopping mesh
@@ -1009,6 +996,10 @@ static int lbs_add_mesh(struct lbs_private *priv)
 	SET_NETDEV_DEV(priv->mesh_dev, priv->dev->dev.parent);
 
 	mesh_dev->flags |= IFF_BROADCAST | IFF_MULTICAST;
+	mesh_dev->sysfs_groups[0] = &lbs_mesh_attr_group;
+	mesh_dev->sysfs_groups[1] = &boot_opts_group;
+	mesh_dev->sysfs_groups[2] = &mesh_ie_group;
+
 	/* Register virtual mesh interface */
 	ret = register_netdev(mesh_dev);
 	if (ret) {
@@ -1016,19 +1007,10 @@ static int lbs_add_mesh(struct lbs_private *priv)
 		goto err_free_netdev;
 	}
 
-	ret = sysfs_create_group(&(mesh_dev->dev.kobj), &lbs_mesh_attr_group);
-	if (ret)
-		goto err_unregister;
-
-	lbs_persist_config_init(mesh_dev);
-
 	/* Everything successful */
 	ret = 0;
 	goto done;
 
-err_unregister:
-	unregister_netdev(mesh_dev);
-
 err_free_netdev:
 	free_netdev(mesh_dev);
 
@@ -1049,8 +1031,6 @@ void lbs_remove_mesh(struct lbs_private *priv)
 
 	netif_stop_queue(mesh_dev);
 	netif_carrier_off(mesh_dev);
-	sysfs_remove_group(&(mesh_dev->dev.kobj), &lbs_mesh_attr_group);
-	lbs_persist_config_remove(mesh_dev);
 	unregister_netdev(mesh_dev);
 	priv->mesh_dev = NULL;
 	kfree(mesh_dev->ieee80211_ptr);
-- 
2.30.2