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Subject: Re: [PATCH] uio: fix wrong return value from uio_mmap()
To:     Hailong Liu <liu.hailong6@zte.com.cn>, gregkh@linuxfoundation.org
Cc:     linux-kernel@vger.kernel.org, jiang.biao2@zte.com.cn,
        zhong.weidong@zte.com.cn
References: <1532046716-49792-1-git-send-email-liu.hailong6@zte.com.cn>
From:   Xiubo Li <xiubli@redhat.com>
Message-ID: <8ff360ff-1b0b-9c29-177d-4a025da58d04@redhat.com>
Date:   Fri, 20 Jul 2018 08:40:48 +0800
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On 2018/7/20 8:31, Hailong Liu wrote:
> uio_mmap has multiple fail paths to set return value to nonzero then
> goto out. However, it always returns *0* from the *out* at end, and
> this will mislead callers who check the return value of this function.
>
> Fixes: 57c5f4df0a5a0ee ("uio: fix crash after the device is unregistered")
> CC: Xiubo Li <xiubli@redhat.com>
> Signed-off-by: Hailong Liu <liu.hailong6@zte.com.cn>
> Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
> ---
>   drivers/uio/uio.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
> index 5d421d7..0ddfda2 100644
> --- a/drivers/uio/uio.c
> +++ b/drivers/uio/uio.c
> @@ -814,7 +814,7 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
>   
>   out:
>   	mutex_unlock(&idev->info_lock);
> -	return 0;
> +	return ret;
Hi Hailong,

Good catch, Thanks.

BRs


>   }
>   
>   static const struct file_operations uio_fops = {