Re: [PATCH] powerpc/kexec_file: Use inclusive range checks for excluded memory

[Sourabh Jain]

On 10/08/26 20:28, Thorsten Blum wrote:
> arch_check_excluded_range() checks if a kexec segment overlaps an
> excluded memory range.
>
> Both ranges use inclusive end addresses, but the overlap check uses
> exclusive comparisons. This skips ranges with start == ->ranges[i].end
> or end == ->ranges[i].start. Use inclusive comparisons instead.
>
> Fixes: 6e5250eaa665 ("powerpc/crash: use generic APIs to locate memory hole for kdump")
> Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxx>
> ---
> Sashiko found this issue when reviewing another patch:
> https://sashiko.dev/#/patchset/20260809162403.18142-2-thorsten.blum%40linux.dev
> ---
>   arch/powerpc/kexec/file_load_64.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
> index 40b74cc4ed3e..32e2b7412a9f 100644
> --- a/arch/powerpc/kexec/file_load_64.c
> +++ b/arch/powerpc/kexec/file_load_64.c
> @@ -58,7 +58,7 @@ int arch_check_excluded_range(struct kimage *image, unsigned long start,
>   
>   	emem = image->arch.exclude_ranges;
>   	for (i = 0; i < emem->nr_ranges; i++)
> -		if (start < emem->ranges[i].end && end > emem->ranges[i].start)
> +		if (start <= emem->ranges[i].end && end >= emem->ranges[i].start)

Like [1] this also extends the condition to check for a 1-byte overlap.
It is unlikely to occur in practice, but I don't see any harm in doing so.
Hence the changes looks good to me. Feel free to add.

Reviewed-by: Sourabh Jain <sourabhjain@xxxxxxxxxxxxx>

[1] 
https://lore.kernel.org/all/ee531113-5a56-4e6e-bc16-95941aa5bbfd@xxxxxxxxxxxxx/

>   			return 1;
>   
>   	return 0;