Re: [PATCH] zsmalloc: use U suffix for negative literals being shifted

From: Minchan Kim
Date: Sun Jan 07 2018 - 10:04:51 EST


Hello,

Sorry for the delay. I have missed this until now. ;-(

On Sun, Dec 24, 2017 at 11:33 AM, Nick Desaulniers
<nick.desaulniers@xxxxxxxxx> wrote:
> Fixes warnings about shifting unsigned literals being undefined
> behavior.
>
> Signed-off-by: Nick Desaulniers <nick.desaulniers@xxxxxxxxx>
> ---
> mm/zsmalloc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index 685049a..5d31458 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -1056,7 +1056,7 @@ static void init_zspage(struct size_class *class, struct zspage *zspage)
> * Reset OBJ_TAG_BITS bit to last link to tell
> * whether it's allocated object or not.
> */
> - link->next = -1 << OBJ_TAG_BITS;
> + link->next = -1U << OBJ_TAG_BITS;

-1UL?

Please, resend it with including Andrew Morton
<akpm@xxxxxxxxxxxxxxxxxxxx> who merges zsmalloc patch into his tree.

Thanks.