Re: [PATCH] mm/sparse: guard the size of mem_section is power of 2

[Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>]

On Mon, Apr 15, 2024 at 9:26 PM Wei Yang <richard.weiyang@xxxxxxxxx> wrote:
>
> We usually have this check, while commit 2a3cb8baef71 ("mm/sparse:
> delete old sparse_init and enable new one") missed to take it.
>
> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
> CC: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
> ---
>  mm/sparse.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/mm/sparse.c b/mm/sparse.c
> index aed0951b87fa..a7d92fe7be19 100644
> --- a/mm/sparse.c
> +++ b/mm/sparse.c
> @@ -560,6 +560,8 @@ void __init sparse_init(void)
>         unsigned long pnum_end, pnum_begin, map_count = 1;
>         int nid_begin;
>
> +       /* see include/linux/mmzone.h 'struct mem_section' definition */
> +       BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));

Reviewed-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>

Thanks,
Pasha