Re: [PATCH] powerpc/kexec_file: Use inclusive range checks for excluded memory
Sourabh Jain <[email protected]>
| Newsgroups | org.ozlabs.lists.linuxppc-dev,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
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 <[email protected]>
> ---
> 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 <[email protected]>
[1]
https://lore.kernel.org/all/[email protected]/
> return 1;
>
> return 0;