[PATCH] Increase kernel text size for x86_64

[Simon Horman]

On Wed, Aug 12, 2009 at 09:41:23AM +0200, Hannes Reinecke wrote:
> Hi all,
> 
> I cannot load a x86_64 kernel with kexec on 2.6.31; the error message is:
> 
> Can't find kernel text map area from kcore
> Cannot load /boot/vmlinuz
> 
> Digging through the source I found a mismatch between the assumed
> kernel text size; kexec has:
> 
> #define KERNEL_TEXT_SIZE  (40UL*1024*1024)
> 
> but on the kernel side we have:
> 
> include/asm/page_64_types.h:
> #define KERNEL_IMAGE_SIZE   (512 * 1024 * 1024)
> 
> And, indeed, changing the definition in kexec-tools to the kernel one
> fixed the problem.
> 
> Not sure if this has been reported before, if so please ignore
> the noise.

Hi,

I'm wondering what effect this would have when using
kexec-tools with older kernels, which presumably have
a smaller value for KERNEL_IMAGE_SIZE.

> diff --git a/kexec/arch/x86_64/crashdump-x86_64.h b/kexec/arch/x86_64/crashdump-x86_64.h
> index 9f4dee9..0e83527 100644
> --- a/kexec/arch/x86_64/crashdump-x86_64.h
> +++ b/kexec/arch/x86_64/crashdump-x86_64.h
> @@ -11,7 +11,7 @@ int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline,
>  #define MAXMEM           0x3fffffffffffUL
>  
>  /* Kernel text size */
> -#define KERNEL_TEXT_SIZE  (40UL*1024*1024)
> +#define KERNEL_TEXT_SIZE  (512UL*1024*1024)
>  
>  #define CRASH_MAX_MEMMAP_NR	(KEXEC_MAX_SEGMENTS + 1)
>  #define CRASH_MAX_MEMORY_RANGES	(MAX_MEMORY_RANGES + 2)