linux-kernel - Re: [PATCH v4 1/3] x86: Introduce a new constant KERNEL_MAPPING

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Date:   Fri, 3 Mar 2017 13:16:14 +0100
From:   Borislav Petkov <bp@...e.de>
To:     Baoquan He <bhe@...hat.com>
Cc:     tglx@...utronix.de, hpa@...or.com, mingo@...hat.com,
        linux-kernel@...r.kernel.org, x86@...nel.org,
        keescook@...omium.org, yinghai@...nel.org, anderson@...hat.com,
        luto@...nel.org, thgarnie@...gle.com, kuleshovmail@...il.com
Subject: Re: [PATCH v4 1/3] x86: Introduce a new constant KERNEL_MAPPING_SIZE

On Fri, Mar 03, 2017 at 08:06:16PM +0800, Baoquan He wrote:
> OK, I am trying to make things clearer, seems I failed. I thought kernel
> iamge size is only allowed to be 512M at most, but can be mapped into 1G
> region.

It doesn't look like it. But we could be missing something. You could
try some git archeology to find out why the 512M limit. It could be "no
reason", it could be remnant from 32-bit, it could be anything...

There's the full git history here too:

https://git.kernel.org/cgit/linux/kernel/git/history/history.git

in case it helps.

> It's fine to me, thing can be solved anyway. Will repost with
> KERNEL_IMAGE_SIZE by default 1G.

I think you should slow down first and try to find out why the 512
default. Then we can talk about changes.

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--