Message-ID: <90d30f18-68e7-d295-7a42-c33554fd8b17@huawei.com>
Date:   Mon, 6 Mar 2023 10:09:16 +0800
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Subject: Re: [PATCH 1/2] mm/damon/paddr: fix folio_size() call after
 folio_put() in damon_pa_young()
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To:     SeongJae Park <sj@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
CC:     <damon@lists.linux.dev>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>, <stable@vger.kernel.org>
References: <20230304193949.296391-1-sj@kernel.org>
 <20230304193949.296391-2-sj@kernel.org>
From:   Kefeng Wang <wangkefeng.wang@huawei.com>
In-Reply-To: <20230304193949.296391-2-sj@kernel.org>
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On 2023/3/5 3:39, SeongJae Park wrote:
> damon_pa_young() is accessing a folio via folio_size() after folio_put()
> for the folio has invoked.  Fix it.
> 

Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>

> Fixes: 397b0c3a584b ("mm/damon/paddr: remove folio_sz field from damon_pa_access_chk_result")
> Cc: <stable@vger.kernel.org> # 6.3.x
> Signed-off-by: SeongJae Park <sj@kernel.org>
> ---
>   mm/damon/paddr.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
> index 3fda00a0f786..10f159b315ea 100644
> --- a/mm/damon/paddr.c
> +++ b/mm/damon/paddr.c
> @@ -130,7 +130,6 @@ static bool damon_pa_young(unsigned long paddr, unsigned long *folio_sz)
>   			accessed = false;
>   		else
>   			accessed = true;
> -		folio_put(folio);
>   		goto out;
>   	}
>   
> @@ -144,10 +143,10 @@ static bool damon_pa_young(unsigned long paddr, unsigned long *folio_sz)
>   
>   	if (need_lock)
>   		folio_unlock(folio);
> -	folio_put(folio);
>   
>   out:
>   	*folio_sz = folio_size(folio);
> +	folio_put(folio);
>   	return accessed;
>   }
>