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From: "H. Peter Anvin" <hpa@zytor.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: kexec@lists.infradead.org, Simon Horman <horms@verge.net.au>,
	Yinghai Lu <yinghai@kernel.org>,
	"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [PATCH] kdump, x86: Process multiple Crash kernel in /proc/iomem
Date: Fri, 22 Mar 2013 14:27:20 -0700	[thread overview]
Message-ID: <514CCCB8.4000108@zytor.com> (raw)
In-Reply-To: <20130322212104.GI4544@redhat.com>

On 03/22/2013 02:21 PM, Vivek Goyal wrote:
> 
> BTW, I had a query about loading 64bit entry point bzImage. In 32bit
> bzImage entry point logic, we used to load bzImage at the beginning
> of memory hole and initrd at the end of memory hole. So that bzImage
> and initramfs are as far as possible and initramfs decompression does
> not overwrite anything or for that matter setting bss are does not
> spill over into initramfs.
> 
> In new code, It looks like we seem to be loading kernel towards the end
> of the hole.
> 
>        addr = add_buffer(info, kernel + kern16_size, k_size,
>                           size, align, 0x100000, -1, -1);
> 
> IIUC, this has potential that new kernel can overwrite some of the old
> kernel's data structure while setting up bss. Shouldn't we do it 32bit
> entry code way where bzImage is loaded towards the beginning of hole and
> initramfs is loaded towards the end of the hole.
> 

Since boot protocol 2.10+ the kernel actively exports how much memory it
needs during its setup phase.

	-hpa



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  reply	other threads:[~2013-03-22 21:27 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20130320163131.GE2273@redhat.com>
2013-03-20 19:24 ` [PATCH] kdump, x86: Process multiple Crash kernel in /proc/iomem Yinghai Lu
2013-03-22 17:59   ` Vivek Goyal
2013-03-22 20:52     ` Yinghai Lu
2013-03-22 21:21       ` Vivek Goyal
2013-03-22 21:27         ` H. Peter Anvin [this message]
2013-03-22 21:35           ` Yinghai Lu
2013-03-22 21:32         ` Yinghai Lu

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