linux-kernel - Re: [PATCHv7] x86/kdump: bugfix, make the behavior of crashkernel=X consistent with kaslr

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Message-ID: <20190131105732.GC6749@zn.tnic>
Date:   Thu, 31 Jan 2019 11:57:32 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Dave Young <dyoung@...hat.com>
Cc:     Pingfan Liu <kernelfans@...il.com>, kexec@...ts.infradead.org,
        Baoquan He <bhe@...hat.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Mike Rapoport <rppt@...ux.vnet.ibm.com>, yinghai@...nel.org,
        vgoyal@...hat.com, Randy Dunlap <rdunlap@...radead.org>,
        x86@...nel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCHv7] x86/kdump: bugfix, make the behavior of crashkernel=X
 consistent with kaslr

On Thu, Jan 31, 2019 at 03:59:07PM +0800, Dave Young wrote:
> As Pingfan/me mentioned in another reply, there are two reasons:
> 1. old kexec-tools can not load kernel to high memory
> 2. ,high will not work on some systems without some amounts of low
> memory so it nees reserve extra low memory, it is bad for people who do
> not want it.

Let's see: we don't enable high by default because of old kexec-tools
and some systems which do some funky reservations.

But this patch kinda enables high by trying a couple more regions.

So we don't really need this - we simply need to tell people to use high
if it fails with KASLR, AFAICT.

-- 
Regards/Gruss,
    Boris.

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