linux-kernel - [PATCH] node: fix device cleanups in error handling code

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Message-ID: <YHA0JUra+F64+NpB@mwanda>
Date:   Fri, 9 Apr 2021 14:01:57 +0300
From:   Dan Carpenter <dan.carpenter@...cle.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     "Rafael J. Wysocki" <rafael@...nel.org>,
        Brice Goglin <Brice.Goglin@...ia.fr>,
        Keith Busch <kbusch@...nel.org>, linux-kernel@...r.kernel.org,
        kernel-janitors@...r.kernel.org, Jason Gunthorpe <jgg@...dia.com>
Subject: [PATCH] node: fix device cleanups in error handling code

We can't use kfree() to free device managed resources so the kfree(dev)
is against the rules.

It's easier to write this code if we open code the device_register() as
a device_initialize() and device_add().  That way if dev_set_name() set
name fails we can call put_device() and it will clean up correctly.

Fixes: acc02a109b04 ("node: Add memory-side caching attributes")
Signed-off-by: Dan Carpenter <dan.carpenter@...cle.com>
---
 drivers/base/node.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index f449dbb2c746..2c36f61d30bc 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -268,21 +268,20 @@ static void node_init_cache_dev(struct node *node)
 	if (!dev)
 		return;
 
+	device_initialize(dev);
 	dev->parent = &node->dev;
 	dev->release = node_cache_release;
 	if (dev_set_name(dev, "memory_side_cache"))
-		goto free_dev;
+		goto put_device;
 
-	if (device_register(dev))
-		goto free_name;
+	if (device_add(dev))
+		goto put_device;
 
 	pm_runtime_no_callbacks(dev);
 	node->cache_dev = dev;
 	return;
-free_name:
-	kfree_const(dev->kobj.name);
-free_dev:
-	kfree(dev);
+put_device:
+	put_device(dev);
 }
 
 /**
@@ -319,25 +318,24 @@ void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs)
 		return;
 
 	dev = &info->dev;
+	device_initialize(dev);
 	dev->parent = node->cache_dev;
 	dev->release = node_cacheinfo_release;
 	dev->groups = cache_groups;
 	if (dev_set_name(dev, "index%d", cache_attrs->level))
-		goto free_cache;
+		goto put_device;
 
 	info->cache_attrs = *cache_attrs;
-	if (device_register(dev)) {
+	if (device_add(dev)) {
 		dev_warn(&node->dev, "failed to add cache level:%d\n",
 			 cache_attrs->level);
-		goto free_name;
+		goto put_device;
 	}
 	pm_runtime_no_callbacks(dev);
 	list_add_tail(&info->node, &node->cache_attrs);
 	return;
-free_name:
-	kfree_const(dev->kobj.name);
-free_cache:
-	kfree(info);
+put_device:
+	put_device(dev);
 }
 
 static void node_remove_caches(struct node *node)
-- 
2.30.2