[PATCH] kexec_file: skip checksum verification when relocations aren't needed

[Baoquan He]

On 06/01/26 at 09:11pm, Michal Clapinski wrote:
...snip... 
> +	/*
> +	 * If all segments were loaded into contiguous memory, there will be no
> +	 * relocations. In that case there is no risk of memory corruption by
> +	 * uncancelled DMA and we can skip checksum calculation.
> +	 */
> +	for (i = 0; i < image->nr_segments; i++) {
> +		if (!image->segment_cma[i]) {
> +			can_skip_checksum = false;
> +			break;
> +		}
> +	}
> +
> +	if (can_skip_checksum) {
> +		pr_info("disabling checksum verification in purgatory\n");

Use pr_debug() or kexec_dprintk() instead because this is unnecessary to
note users if it's a normal action?

Except of this, the overral looks good to me.

Acked-by: Baoquan He <baoquan.he at linux.dev>

> +		goto skip_checksum;
> +	}
> +
>  	for (j = i = 0; i < image->nr_segments; i++) {
>  		struct kexec_segment *ksegment;
>  
> @@ -867,6 +885,7 @@ static int kexec_calculate_store_digests(struct kimage *image)
>  		j++;
>  	}
>  
> +skip_checksum:
>  	sha256_final(&sctx, digest);
>  
>  	ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
> -- 
> 2.54.0.929.g9b7fa37559-goog
>