Re: [PATCH 1/2] mm/damon/paddr: fix folio_size() call after folio_put() in damon_pa_young()

[Kefeng Wang]

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@xxxxxxxxxx>

> Fixes: 397b0c3a584b ("mm/damon/paddr: remove folio_sz field from damon_pa_access_chk_result")
> Cc: <stable@xxxxxxxxxxxxxxx> # 6.3.x
> Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
> ---
>   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;
>   }
>