[PATCH v2 2/3] lib: sbi: add more restriction to domain region subset check

[Anup Patel]

On Tue, Oct 10, 2023 at 6:30 AM Inochi Amaoto <inochiama at outlook.com> wrote:
>
> make is_region_subset() check the bound of the domain region, so it can
> handle the domain region with the same base and length.
>
> Signed-off-by: Inochi Amaoto <inochiama at outlook.com>

Important fact here is that regB_start < regB_end and
regA_start < regA_end because order == 0 region is of
size 1 byte.

When regB_start == regA_start and regB_end == regA_end,
the following is the outcome of the expressions in the existing
"if ()" check.

(regB_start <= regA_start) == true
(regA_start < regB_end) == true
(regB_start < regA_end) == true
(regA_end <= regB_end) == true

Based on the above, I don't see how this patch helps.

Regards,
Anup



> ---
>  lib/sbi/sbi_domain.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/sbi/sbi_domain.c b/lib/sbi/sbi_domain.c
> index 283b598..2b9d16f 100644
> --- a/lib/sbi/sbi_domain.c
> +++ b/lib/sbi/sbi_domain.c
> @@ -185,8 +185,8 @@ static bool is_region_subset(const struct sbi_domain_memregion *regA,
>         ulong regB_end = regB->base + (BIT(regB->order) - 1);
>
>         if ((regB_start <= regA_start) &&
> -           (regA_start < regB_end) &&
> -           (regB_start < regA_end) &&
> +           (regB_start <= regA_end) &&
> +           (regA_start <= regB_end) &&
>             (regA_end <= regB_end))
>                 return true;
>
> --
> 2.42.0
>