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Message-ID: <e0f268f7-d939-8732-af47-a9cd01025afe@gmail.com>
Date:   Wed, 26 Apr 2023 12:06:56 +0800
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Subject: Re: [PATCH 01/34] maple_tree: Fix static analyser cppcheck issue
To:     "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        maple-tree@lists.infradead.org,
        David Binderman <dcb314@hotmail.com>,
        Andrew Morton <akpm@linux-foundation.org>
References: <20230425140955.3834476-1-Liam.Howlett@oracle.com>
 <20230425140955.3834476-2-Liam.Howlett@oracle.com>
From:   Peng Zhang <perlyzhang@gmail.com>
In-Reply-To: <20230425140955.3834476-2-Liam.Howlett@oracle.com>
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在 2023/4/25 22:09, Liam R. Howlett 写道:
> Static analyser of the maple tree code noticed that the split variable
> is being used to dereference into an array prior to checking the
> variable itself.  Fix this issue by changing the order of the statement
> to check the variable first.
>
> Reported-by: David Binderman <dcb314@hotmail.com>
> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>

Reviewed-by: Peng Zhang<zhangpeng.00@bytedance.com>

> ---
>   lib/maple_tree.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 110a36479dced..9cf4fca42310c 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -1943,8 +1943,9 @@ static inline int mab_calc_split(struct ma_state *mas,
>   		 * causes one node to be deficient.
>   		 * NOTE: mt_min_slots is 1 based, b_end and split are zero.
>   		 */
> -		while (((bn->pivot[split] - min) < slot_count - 1) &&
> -		       (split < slot_count - 1) && (b_end - split > slot_min))
> +		while ((split < slot_count - 1) &&
> +		       ((bn->pivot[split] - min) < slot_count - 1) &&
> +		       (b_end - split > slot_min))
>   			split++;
>   	}
>