[PATCH] x86, realmode: set real_mode permissions early

From: Borislav Petkov
Date: Thu Dec 27 2012 - 13:22:26 EST


> commit 77e277cb85290a183bbc1995a1cd839b1c216f25
> Subject: [PATCH] x86, realmode: set real_mode permissions early
> Author: Yinghai Lu <yinghai@xxxxxxxxxx>
> Date: Mon Dec 24 18:00:21 2012 -0800
>
> x86, realmode: set real_mode permissions early
>
> We need to set trampoline code to EXEC early before we do smp
> AP bootings.
>
> Found the problem after switching to #PF handler set page table,
> and we do not set initial kernel low mapping with EXEC anymore.
>
> Change to use early_initcall instead that will make sure tramopline
> will have EXEC set.
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
>
> diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
> index 80450261215c..0b7e840ad4d4 100644
> --- a/arch/x86/realmode/init.c
> +++ b/arch/x86/realmode/init.c
> @@ -111,5 +111,4 @@ static int __init set_real_mode_permissions(void)
>
> return 0;
> }
> -
> -arch_initcall(set_real_mode_permissions);
> +early_initcall(set_real_mode_permissions);

I'm looking at this patch in the -v8 branch: you need to update the
comment above that function to say that trampoline code needs to be
marked X now earlier.

Thanks.

--
Regards/Gruss,
Boris.
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