Re: [x86-tip] RSDP changes converted i4790 box SMP -> UP

[Juergen Gross]

On 15/01/18 16:32, Ingo Molnar wrote:
> 
> * Juergen Gross <jgross@xxxxxxxx> wrote:
> 
>> On 15/01/18 15:56, Borislav Petkov wrote:
>>> On Mon, Jan 15, 2018 at 03:52:25PM +0100, Juergen Gross wrote:
>>>> Ingo, with my finding that above boot failure is related to a bug in
>>>> openSUSE's grub2 (I've verified it soesn't exist in upstream grub2),
>>>
>>> The box I'm seeing this on has SLES12-SP2 grub:
>>>
>>> Version        : 2.02~beta2-115.9.1
>>>
>>> Does it have the same bug?
>>
>> The patch introducing this problem is from 2012. So I guess: yes.
> 
> I suspect this makes it a widespread, unintended ABI. Can we detect and somehow avoid it?
> 
> The boot protocol ABI sucks if it's fragile against such mistakes.

Well, copying sizeof(setup_header) into grub2 and then coyping back just
1024 bytes is plain wrong. It is a miracle nothing broke up to now.


Juergen