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Subject: Re: [PATCH 1/1] mm/mmap_lock: Remove unnecessary 'NULL' values from
 Pointer
To:     XU pengfei <xupengfei@nfschina.com>
CC:     <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
References: <20221008093942.3982-1-xupengfei@nfschina.com>
From:   Miaohe Lin <linmiaohe@huawei.com>
Message-ID: <45e6ce25-f0b6-4461-b88d-5b6bb78cabba@huawei.com>
Date:   Sat, 8 Oct 2022 20:21:21 +0800
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On 2022/10/8 17:39, XU pengfei wrote:
> Pointer variables allocate memory first, and then judge. There is no
> need to initialize the assignment.
> 
> Signed-off-by: XU pengfei <xupengfei@nfschina.com>
> ---
>  mm/mmap_lock.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/mmap_lock.c b/mm/mmap_lock.c
> index 1854850b4b89..65a57731aa15 100644
> --- a/mm/mmap_lock.c
> +++ b/mm/mmap_lock.c
> @@ -198,7 +198,7 @@ void trace_mmap_lock_unreg(void)
>   */
>  static const char *get_mm_memcg_path(struct mm_struct *mm)
>  {
> -	char *buf = NULL;
> +	char *buf;
>  	struct mem_cgroup *memcg = get_mem_cgroup_from_mm(mm);
>  
>  	if (memcg == NULL)

It seems if memcg == NULL, the code will go to out and return uninitialized @buf?

Thanks,
Miaohe Lin