[PATCH v2 1/4] uacce: fix for cdev memory leak

[Chenghai Huang <huangchenghai2@huawei.com>]

From: Wenkai Lin <linwenkai6@hisilicon.com>

If cdev_device_add failed, it is hard to determine
whether cdev_del has been executed, which lead to a
memory leak issue, so we use cdev_init to avoid it.

Fixes: 015d239ac014 ("uacce: add uacce driver")
Cc: stable@vger.kernel.org
Signed-off-by: Wenkai Lin <linwenkai6@hisilicon.com>
Signed-off-by: Chenghai Huang <huangchenghai2@huawei.com>
---
 drivers/misc/uacce/uacce.c | 13 ++++---------
 include/linux/uacce.h      |  2 +-
 2 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c
index 42e7d2a2a90c..12370469f646 100644
--- a/drivers/misc/uacce/uacce.c
+++ b/drivers/misc/uacce/uacce.c
@@ -522,14 +522,10 @@ int uacce_register(struct uacce_device *uacce)
 	if (!uacce)
 		return -ENODEV;
 
-	uacce->cdev = cdev_alloc();
-	if (!uacce->cdev)
-		return -ENOMEM;
-
-	uacce->cdev->ops = &uacce_fops;
-	uacce->cdev->owner = THIS_MODULE;
+	cdev_init(&uacce->cdev, &uacce_fops);
+	uacce->cdev.owner = THIS_MODULE;
 
-	return cdev_device_add(uacce->cdev, &uacce->dev);
+	return cdev_device_add(&uacce->cdev, &uacce->dev);
 }
 EXPORT_SYMBOL_GPL(uacce_register);
 
@@ -568,8 +564,7 @@ void uacce_remove(struct uacce_device *uacce)
 		unmap_mapping_range(q->mapping, 0, 0, 1);
 	}
 
-	if (uacce->cdev)
-		cdev_device_del(uacce->cdev, &uacce->dev);
+	cdev_device_del(&uacce->cdev, &uacce->dev);
 	xa_erase(&uacce_xa, uacce->dev_id);
 	/*
 	 * uacce exists as long as there are open fds, but ops will be freed
diff --git a/include/linux/uacce.h b/include/linux/uacce.h
index e290c0269944..98b896192a44 100644
--- a/include/linux/uacce.h
+++ b/include/linux/uacce.h
@@ -126,7 +126,7 @@ struct uacce_device {
 	bool is_vf;
 	u32 flags;
 	u32 dev_id;
-	struct cdev *cdev;
+	struct cdev cdev;
 	struct device dev;
 	struct mutex mutex;
 	void *priv;
-- 
2.33.0