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Date:   Mon, 14 Jan 2019 15:26:32 -0500 (EST)
From:   Dave Anderson <anderson@redhat.com>
To:     Borislav Petkov <bp@alien8.de>
Cc:     Kazuhito Hagio <k-hagio@ab.jp.nec.com>,
        Lianbo Jiang <lijiang@redhat.com>,
        linux-kernel@vger.kernel.org, kexec@lists.infradead.org,
        tglx@linutronix.de, mingo@redhat.com, x86@kernel.org,
        akpm@linux-foundation.org, bhe@redhat.com, dyoung@redhat.com,
        linux-doc@vger.kernel.org
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Subject: Re: [PATCH 1/2 v6] kdump: add the vmcoreinfo documentation
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----- Original Message -----
> On Mon, Jan 14, 2019 at 03:07:33PM -0500, Dave Anderson wrote:
> > That's what it *does* utilize -- it takes a standalone vmcore dumpfile, and
> > pulls out the OSRELEASE string from it, so that a user can determine what
> > vmlinux file should be used with that vmcore for normal crash analysis.
> 
> And the vmcoreinfo is part of the vmcore, right?

Correct.

> 
> So it can just as well read out the address of init_uts_ns and get the
> kernel version from there.

No.  It needs *both* the vmlinux file and the vmcore file in order to read kernel
virtual memory, so just having a kernel virtual address is insufficient.

So it's a chicken-and-egg situation.  This particular --osrelease option is used
to determine *what* vmlinux file would be required for an actual crash analysis 
session.

Dave