Re: [PATCH] vhost: vringh: Modify the return value check

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Sep 10, 2025 at 05:17:38PM +0800, zhangjiao2 wrote:
> From: zhang jiao <zhangjiao2@cmss.chinamobile.com>
> 
> The return value of copy_from_iter and copy_to_iter can't be negative,
> check whether the copied lengths are equal.
> 
> Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com>

Given copy_to_iter was fixed on net, how about applying
this one on net, too?


> ---
>  drivers/vhost/vringh.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
> index 9f27c3f6091b..0c8a17cbb22e 100644
> --- a/drivers/vhost/vringh.c
> +++ b/drivers/vhost/vringh.c
> @@ -1115,6 +1115,7 @@ static inline int copy_from_iotlb(const struct vringh *vrh, void *dst,
>  		struct iov_iter iter;
>  		u64 translated;
>  		int ret;
> +		size_t size;
>  
>  		ret = iotlb_translate(vrh, (u64)(uintptr_t)src,
>  				      len - total_translated, &translated,
> @@ -1132,9 +1133,9 @@ static inline int copy_from_iotlb(const struct vringh *vrh, void *dst,
>  				      translated);
>  		}
>  
> -		ret = copy_from_iter(dst, translated, &iter);
> -		if (ret < 0)
> -			return ret;
> +		size = copy_from_iter(dst, translated, &iter);
> +		if (size != translated)
> +			return -EFAULT;
>  
>  		src += translated;
>  		dst += translated;
> -- 
> 2.33.0
> 
>