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Subject: Re: [PATCH -next] USB: gadget: f_fs: Use ERR_CAST instead of
 ERR_PTR(PTR_ERR(...))
To:     Greg KH <gregkh@linuxfoundation.org>
CC:     <balbi@kernel.org>, <linux-usb@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <20210519023032.19812-1-yuehaibing@huawei.com>
 <YKeeHDy/VAhuoG6B@kroah.com>
From:   YueHaibing <yuehaibing@huawei.com>
Message-ID: <91b40f9e-9de2-0d16-7eb1-50e5a91fb077@huawei.com>
Date:   Sun, 23 May 2021 14:33:36 +0800
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On 2021/5/21 19:48, Greg KH wrote:
> On Wed, May 19, 2021 at 10:30:32AM +0800, YueHaibing wrote:
>> A coccicheck run provided information like the following.
>>
>> ./drivers/usb/gadget/function/f_fs.c:3832:9-16:
>>  WARNING: ERR_CAST can be used with data
>>
>> Use ERR_CAST to fix this.
>>
>> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
>> ---
>>  drivers/usb/gadget/function/f_fs.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
>> index bf109191659a..61110ff52f49 100644
>> --- a/drivers/usb/gadget/function/f_fs.c
>> +++ b/drivers/usb/gadget/function/f_fs.c
>> @@ -3829,7 +3829,7 @@ static char *ffs_prepare_buffer(const char __user *buf, size_t len)
>>  
>>  	data = memdup_user(buf, len);
>>  	if (IS_ERR(data))
>> -		return ERR_PTR(PTR_ERR(data));
>> +		return ERR_CAST(data);
> 
> This should just be:
> 		return PTR_ERR(data);
> right?

ffs_prepare_buffer() should return an ERR_PTR() encoded error code on failure,

maybe there just do:

		return data;

> 
> No need for 2 casts to happen here.
> 
> thanks,
> 
> greg k-h
> .
>