2021-04-26 09:36:52

by Yang Li

Subject: [PATCH] HID: hiddev: return -ENOMEM when kmalloc failed

The driver is using -1 instead of the -ENOMEM defined macro to
specify that a buffer allocation failed. Using the correct error
code is more intuitive.

Smatch tool warning:
drivers/hid/usbhid/hiddev.c:894 hiddev_connect() warn: returning -1
instead of -ENOMEM is sloppy

No functional change, just more standardized.

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Yang Li <[email protected]>
---
drivers/hid/usbhid/hiddev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index 45e0b1c..88020f3 100644
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -891,7 +891,7 @@ int hiddev_connect(struct hid_device *hid, unsigned int force)
}

if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
- return -1;
+ return -ENOMEM;

init_waitqueue_head(&hiddev->wait);
INIT_LIST_HEAD(&hiddev->list);
--
1.8.3.1

2021-04-26 12:15:10

by Johan Hovold

Subject: Re: [PATCH] HID: hiddev: return -ENOMEM when kmalloc failed

On Mon, Apr 26, 2021 at 05:35:26PM +0800, Yang Li wrote:
> The driver is using -1 instead of the -ENOMEM defined macro to
> specify that a buffer allocation failed. Using the correct error
> code is more intuitive.
>
> Smatch tool warning:
> drivers/hid/usbhid/hiddev.c:894 hiddev_connect() warn: returning -1
> instead of -ENOMEM is sloppy
>
> No functional change, just more standardized.
>
> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Yang Li <[email protected]>
> ---
> drivers/hid/usbhid/hiddev.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
> index 45e0b1c..88020f3 100644
> --- a/drivers/hid/usbhid/hiddev.c
> +++ b/drivers/hid/usbhid/hiddev.c
> @@ -891,7 +891,7 @@ int hiddev_connect(struct hid_device *hid, unsigned int force)
> }
>
> if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
> - return -1;
> + return -ENOMEM;

Please try to understand the code that you're changing based on feedback
from some tool.

All other error paths here return -1 and the return value of this
function is only compared to zero.

How is changing only one of these paths an improvement in any way?

>
> init_waitqueue_head(&hiddev->wait);
> INIT_LIST_HEAD(&hiddev->list);

Johan