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SubjectRe: [PATCH] x86, realmode: set real_mode permissions early
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On Thu, Dec 27, 2012 at 10:22 AM, Borislav Petkov <bp@alien8.de> wrote:
>> commit 77e277cb85290a183bbc1995a1cd839b1c216f25
>> Subject: [PATCH] x86, realmode: set real_mode permissions early
>> Author: Yinghai Lu <yinghai@kernel.org>
>> 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@kernel.org>
>>
>> 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.

Not sure if we really need to add such comment in the code.

Peter, what is your idea about this?

Yinghai


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