Re: [PATCH v3 2/4] prtcl: introduce PR_MTE_STORE_ONLY

[David Hildenbrand]

On 10.04.25 10:07, Yeoreum Yun wrote:
> PR_MTE_STORE_ONLY is used to restrict the MTE tag check for store
> opeartion only.
>
> Signed-off-by: Yeoreum Yun <yeoreum.yun@xxxxxxx>
> ---
>   include/uapi/linux/prctl.h | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
> index 15c18ef4eb11..83ac566251d8 100644
> --- a/include/uapi/linux/prctl.h
> +++ b/include/uapi/linux/prctl.h
> @@ -244,6 +244,8 @@ struct prctl_mm_map {
>   # define PR_MTE_TAG_MASK		(0xffffUL << PR_MTE_TAG_SHIFT)
>   /* Unused; kept only for source compatibility */
>   # define PR_MTE_TCF_SHIFT		1
> +/* MTE tag check store only */
> +# define PR_MTE_STORE_ONLY		(1UL << 19)

That is the next available bit after PR_MTE_TAG_MASK, correct?

Would we want to leave some space to grow PR_MTE_TAG_MASK in the future 
(could that happen?)?

--
Cheers,

David / dhildenb