2012-08-15 19:32:00

by Alexey Khoroshilov

Subject: [PATCH] HID: hidraw: improve error handling in hidraw_init()

Several improvements in error handling:
- do not report success if alloc_chrdev_region() failed
- check for error code of cdev_add()
- use unregister_chrdev_region() instead of unregister_chrdev()
if class_create() failed

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <[email protected]>
---
drivers/hid/hidraw.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index 36fa77b..15e6660 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -549,21 +549,28 @@ int __init hidraw_init(void)

if (result < 0) {
pr_warn("can't get major number\n");
- result = 0;
goto out;
}

hidraw_class = class_create(THIS_MODULE, "hidraw");
if (IS_ERR(hidraw_class)) {
result = PTR_ERR(hidraw_class);
- unregister_chrdev(hidraw_major, "hidraw");
- goto out;
+ goto error_cdev;
}

cdev_init(&hidraw_cdev, &hidraw_ops);
- cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
+ result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
+ if (result < 0)
+ goto error_class;
+
out:
return result;
+
+error_class:
+ class_destroy(hidraw_class);
+error_cdev:
+ unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
+ goto out;
}

void hidraw_exit(void)
--
1.7.9.5

2012-08-15 19:38:10

by Jiri Kosina

Subject: Re: [PATCH] HID: hidraw: improve error handling in hidraw_init()

On Wed, 15 Aug 2012, Alexey Khoroshilov wrote:

> Several improvements in error handling:
> - do not report success if alloc_chrdev_region() failed
> - check for error code of cdev_add()
> - use unregister_chrdev_region() instead of unregister_chrdev()
> if class_create() failed
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> ---
> drivers/hid/hidraw.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
> index 36fa77b..15e6660 100644
> --- a/drivers/hid/hidraw.c
> +++ b/drivers/hid/hidraw.c
> @@ -549,21 +549,28 @@ int __init hidraw_init(void)
>
> if (result < 0) {
> pr_warn("can't get major number\n");
> - result = 0;
> goto out;
> }
>
> hidraw_class = class_create(THIS_MODULE, "hidraw");
> if (IS_ERR(hidraw_class)) {
> result = PTR_ERR(hidraw_class);
> - unregister_chrdev(hidraw_major, "hidraw");
> - goto out;
> + goto error_cdev;
> }
>
> cdev_init(&hidraw_cdev, &hidraw_ops);
> - cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
> + result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
> + if (result < 0)
> + goto error_class;
> +
> out:
> return result;
> +
> +error_class:
> + class_destroy(hidraw_class);
> +error_cdev:
> + unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
> + goto out;
> }
>
> void hidraw_exit(void)

Applied, thanks Alexey.

--
Jiri Kosina
SUSE Labs