linux-kernel - Re: [PATCH] userfaultfd: use helper function range_in

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Message-ID: <e77ba42b-a2a4-5cdc-7038-287c28ef8cd7@redhat.com>
Date:   Mon, 17 Apr 2023 12:33:01 +0200
From:   David Hildenbrand <david@...hat.com>
To:     Peng Zhang <zhangpeng362@...wei.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, akpm@...ux-foundation.org
Cc:     mike.kravetz@...cle.com, wangkefeng.wang@...wei.com,
        sunnanyong@...wei.com
Subject: Re: [PATCH] userfaultfd: use helper function range_in_vma()

On 17.04.23 02:39, Peng Zhang wrote:
> From: ZhangPeng <zhangpeng362@...wei.com>
> 
> We could use range_in_vma() to check if dst_start, dst_start + len are
> within the dst_vma range. Minor readability improvement.
> 
> Signed-off-by: ZhangPeng <zhangpeng362@...wei.com>
> ---
>   mm/userfaultfd.c | 6 +-----
>   1 file changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
> index 11cfd82c6726..e97a0b4889fc 100644
> --- a/mm/userfaultfd.c
> +++ b/mm/userfaultfd.c
> @@ -31,11 +31,7 @@ struct vm_area_struct *find_dst_vma(struct mm_struct *dst_mm,
>   	struct vm_area_struct *dst_vma;
>   
>   	dst_vma = find_vma(dst_mm, dst_start);
> -	if (!dst_vma)
> -		return NULL;
> -
> -	if (dst_start < dst_vma->vm_start ||
> -	    dst_start + len > dst_vma->vm_end)
> +	if (!range_in_vma(dst_vma, dst_start, dst_start + len))
>   		return NULL;
>   
>   	/*

Reviewed-by: David Hildenbrand <david@...hat.com>

-- 
Thanks,

David / dhildenb