Re: [RFC PATCH] x86: Make sure verify_cpu has a good stack

From: H. Peter Anvin
Date: Wed Mar 02 2016 - 17:33:27 EST


On March 2, 2016 2:28:42 PM PST, Borislav Petkov <bp@xxxxxxxxx> wrote:
>On Wed, Mar 02, 2016 at 02:11:51PM -0800, H. Peter Anvin wrote:
>> Not sure if we need a reference to _text here.
>
>Ah, so stack_start is in .ref.data, I guess we can add a __ref_data
>marker in vmlinux.lds.S to denote the start of the .ref.data section
>and
>use that for calculating the delta...

I'm trying to think of any reason why we couldn't simply have a symbol at the top of the initial stack? Then a simple leaq would suffice; this is for the BSP after all.
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