Subject: Re: [PATCH RESEND v1 5/5] crash: option to let arch decide mem range is usable

From: Baoquan he <[email-masked]>
Date: Wed, 8 Jan 2025 19:38:13 +0800

On 01/08/25 at 03:44pm, Sourabh Jain wrote:
...snip...
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index f0e9f8eda7a3..407f8b0346aa 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -205,6 +205,15 @@ static inline int arch_kimage_file_post_load_cleanup(struct kimage *image)
>  }
>  #endif
>  
> +#ifndef arch_check_excluded_range
> +static inline int arch_check_excluded_range(struct kimage *image,
> +					    unsigned long start,
> +					    unsigned long end)
> +{
> +	return 0;
> +}
> +#endif
> +
>  #ifdef CONFIG_KEXEC_SIG
>  #ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
>  int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len);
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index 3eedb8c226ad..52e1480dbfa1 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -464,6 +464,12 @@ static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
>  			continue;
>  		}
>  
> +		/* Make sure this does not conflict exclude range */
                                                   ^
                Make sure this doesn't conflict with excluded range?

> +		if (arch_check_excluded_range(image, temp_start, temp_end)) {
> +			temp_start = temp_start - PAGE_SIZE;
> +			continue;
> +		}
> +
>  		/* We found a suitable memory range */
>  		break;
>  	} while (1);
> @@ -498,6 +504,12 @@ static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
>  			continue;
>  		}
>  
> +		/* Make sure this does not conflict exclude range */
                                                   ^
                                                 Ditto.

> +		if (arch_check_excluded_range(image, temp_start, temp_end)) {
> +			temp_start = temp_start + PAGE_SIZE;
> +			continue;
> +		}
> +
>  		/* We found a suitable memory range */
>  		break;
>  	} while (1);
> -- 
> 2.47.1
>