Re: [PATCH 2/5] platform/x86: dell-ddv: Return error if buffer is empty

From: Hans de Goede <hdegoede@redhat.com>
To: Armin Wolf <W_Armin@gmx.de>, markgross@kernel.org
Cc: jdelvare@suse.com, linux@roeck-us.net,
	platform-driver-x86@vger.kernel.org, linux-hwmon@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/5] platform/x86: dell-ddv: Return error if buffer is empty
Date: Mon, 30 Jan 2023 16:05:53 +0100	[thread overview]
Message-ID: <94ae8042-89f7-9210-1bda-a22dd9fe7d4d@redhat.com> (raw)
In-Reply-To: <20230126194021.381092-3-W_Armin@gmx.de>

Hi,

On 1/26/23 20:40, Armin Wolf wrote:
> In several cases, the DDV WMI interface can return buffers
> with a length of zero. Return -ENODATA in such a case for
> proper error handling. Also replace some -EIO errors with
> more specialized ones.
> 
> Signed-off-by: Armin Wolf <W_Armin@gmx.de>

Thank you for your patch, I've applied this patch to my review-hans 
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Note it will show up in my review-hans branch once I've pushed my
local branch there, which might take a while.

Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.

Regards,

Hans

> ---
>  drivers/platform/x86/dell/dell-wmi-ddv.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/platform/x86/dell/dell-wmi-ddv.c b/drivers/platform/x86/dell/dell-wmi-ddv.c
> index 9cb6ae42dbdc..f99c4cb686fd 100644
> --- a/drivers/platform/x86/dell/dell-wmi-ddv.c
> +++ b/drivers/platform/x86/dell/dell-wmi-ddv.c
> @@ -11,6 +11,7 @@
>  #include <linux/debugfs.h>
>  #include <linux/device.h>
>  #include <linux/dev_printk.h>
> +#include <linux/errno.h>
>  #include <linux/kernel.h>
>  #include <linux/kstrtox.h>
>  #include <linux/math.h>
> @@ -125,21 +126,27 @@ static int dell_wmi_ddv_query_buffer(struct wmi_device *wdev, enum dell_ddv_meth
>  	if (ret < 0)
>  		return ret;
> 
> -	if (obj->package.count != 2)
> -		goto err_free;
> +	if (obj->package.count != 2 ||
> +	    obj->package.elements[0].type != ACPI_TYPE_INTEGER ||
> +	    obj->package.elements[1].type != ACPI_TYPE_BUFFER) {
> +		ret = -ENOMSG;
> 
> -	if (obj->package.elements[0].type != ACPI_TYPE_INTEGER)
>  		goto err_free;
> +	}
> 
>  	buffer_size = obj->package.elements[0].integer.value;
> 
> -	if (obj->package.elements[1].type != ACPI_TYPE_BUFFER)
> +	if (!buffer_size) {
> +		ret = -ENODATA;
> +
>  		goto err_free;
> +	}
> 
>  	if (buffer_size > obj->package.elements[1].buffer.length) {
>  		dev_warn(&wdev->dev,
>  			 FW_WARN "WMI buffer size (%llu) exceeds ACPI buffer size (%d)\n",
>  			 buffer_size, obj->package.elements[1].buffer.length);
> +		ret = -EMSGSIZE;
> 
>  		goto err_free;
>  	}
> @@ -151,7 +158,7 @@ static int dell_wmi_ddv_query_buffer(struct wmi_device *wdev, enum dell_ddv_meth
>  err_free:
>  	kfree(obj);
> 
> -	return -EIO;
> +	return ret;
>  }
> 
>  static int dell_wmi_ddv_query_string(struct wmi_device *wdev, enum dell_ddv_method method,
> --
> 2.30.2
> 