[PATCH 1/1] spl: spl_legacy: simplify spl_parse_legacy_validate

[Marek Vasut]

On 7/22/23 20:46, Heinrich Schuchardt wrote:
> The check for an overlap of the loaded image and SPL is overly
> complicated.
> 
> Fixes: 77aed22b48ab ("spl: spl_legacy: Add extra address checks")
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> ---
>   common/spl/spl_legacy.c | 5 +----
>   1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/common/spl/spl_legacy.c b/common/spl/spl_legacy.c
> index 095443c63d..9246f555e3 100644
> --- a/common/spl/spl_legacy.c
> +++ b/common/spl/spl_legacy.c
> @@ -22,10 +22,7 @@ static void spl_parse_legacy_validate(uintptr_t start, uintptr_t size)
>   	uintptr_t spl_end = (uintptr_t)_image_binary_end;
>   	uintptr_t end = start + size;
>   
> -	if ((start >= spl_start && start < spl_end) ||
> -	    (end > spl_start && end <= spl_end) ||
> -	    (start < spl_start && end >= spl_end) ||
> -	    (start > end && end > spl_start))
> +	if (end > spl_start && start < spl_end)
>   		panic("SPL: Image overlaps SPL\n");
>   
>   	if (size > CONFIG_SYS_BOOTM_LEN)

Does this handle address space wrap around ? This:

=====blob=====|..............|=====blob=====
.....|==spl==|..............................

Hint: it does not.

+CC Rasmus.

Look at all the other checks in U-Boot which do, and first factor them 
out into one check functions, so we can improve on that one. Second, use 
that function all over the place. Third, improve on it.