Re: [PATCH] mm: hugetlb: checking for IS_ERR() instead of NULL

[Nigel Christian <nigel.l.christian@gmail.com>]

On Tue, Jun 01, 2021 at 12:25:40PM +0300, Dan Carpenter wrote:
> The alloc_migrate_huge_page() doesn't return error pointers, it returns
> NULL.

Hi Dan,

I'm trying to start using smatch. Is this in the warns report?
Wasn't able to find using smatch_scripts/kchecker mm/hugetlb.c (T_T)

> 
> Fixes: ab45bc8b5910 ("mm, hugetlb: fix resv_huge_pages underflow on UFFDIO_COPY")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>  mm/hugetlb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 69a4b551c157..3221c94b4749 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -5103,7 +5103,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
>  			 */
>  			page = alloc_migrate_huge_page(h, gfp_mask, node,
>  						       nodemask);
> -			if (IS_ERR(page)) {
> +			if (!page) {
>  				ret = -ENOMEM;
>  				goto out;
>  			}
> -- 
> 2.30.2
>