Re: [PATCH] x86: Remove excess calculations for heap_end_ptr

From: Jeremiah Mahler
Date: Fri Dec 26 2014 - 09:35:54 EST


Alexander,

On Fri, Dec 26, 2014 at 06:22:42PM +0600, Alexander Kuleshov wrote:
> heap_end_ptr default value defined as _end+STACK_SZE-512, but
STACK_SIZE

> STACK_SIZE is already 512.
>
> Signed-off-by: Alexander Kuleshov <kuleshovmail@xxxxxxxxx>
> ---
> arch/x86/boot/header.S | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
> index 16ef025..c69b870 100644
> --- a/arch/x86/boot/header.S
> +++ b/arch/x86/boot/header.S
> @@ -342,7 +342,7 @@ ramdisk_size: .long 0 # its size in bytes
> bootsect_kludge:
> .long 0 # obsolete
>
> -heap_end_ptr: .word _end+STACK_SIZE-512
> +heap_end_ptr: .word _end
> # (Header version 0x0201 or later)
> # space from here (exclusive) down to
> # end of setup code can be used by setup

So right now STACK_SIZE happens to be 512 so STACK_SIZE-512 is zero.
What happens if someone changes the size of STACK_SIZE?

This change doesn't fix any problem right now and creates potential
problems in the future.

> --
> 2.2.1.201.gbbcefff
>
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--
- Jeremiah Mahler
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