Date: Tue, 2 Jul 2013 12:23:23 -0400
From: Vivek Goyal <vgoyal@redhat.com>
To: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>,
        Jan Willeke <willeke@de.ibm.com>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        linux-kernel@vger.kernel.org, kexec@lists.infradead.org
Subject: Re: [PATCH v6 2/5] s390/vmcore: Use ELF header in new memory feature
Message-ID: <20130702162322.GD22603@redhat.com>
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On Mon, Jul 01, 2013 at 09:32:36PM +0200, Michael Holzheu wrote:

[..]
> +ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
> +{
> +	void *src = (void *)(unsigned long)*ppos;
> +
> +	src = elfcorehdr_newmem ? src : src - OLDMEM_BASE;

Seriously, we need to get rid of all this OLDMEM_BASE logic in s390
specific code. For regular kdump, it is no different than x86. Only
special handling required for zfcpdump for HSA region.

Why do we need above. Is it to cover the case where elfcorehdr have
been prepared by user space? Are elf headers initially stored in
reserved region and then swapped. Why do we need to swap these or
why kexec-tools could not take care of swapping it.

Anyway, I think in a separate patch series it is good to cleanup
s390 code for removing all the swap logic related stuff. I can't
wrap my head around it anymore.

Thanks
Vivek
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