Re: [PATCH v8 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory

From: Borislav Petkov
Date: Tue Nov 06 2018 - 13:45:29 EST


On Thu, Oct 25, 2018 at 09:40:51AM -0400, Masayoshi Mizuma wrote:
> I have another idea to solve this issue. Adding a SRAT parsing code
> to arch/x86/mm/kaslr.c. It is useful for both EFI and BIOS and
> also we don't need a new kernel parameter...
> Dose the idea make sense?

Ok, having swapped the whole thing back into my brain, forget what I
said earlier today.

Didn't we talk about passing info with setup_data to the later kernel
stage? You even had a patch:

https://lkml.kernel.org/r/20181022154204.kagmdb55jtoez4ca@gabell

So what is that "idea" again about adding SRAT parsing code to
arch/x86/mm/kaslr.c?!?!

The intent of passing info with setup_data is to *avoid* parsing SRAT
yet another time and duplicating that code one more time.

IOW:

* The first place that needs SRAT parsing, does the parsing - i.e., the
compressed stage.

* Later stages get information passed to them with setup_data. No second
parsing.

Ok?

--
Regards/Gruss,
Boris.

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