Re: Determine version of kernel that produced vmcore

Bernhard Walle
2007-07-11T08:58:45Z

* Vivek Goyal <vgoyal@in.ibm.com> [2007-07-11 08:07]:
> On Tue, Jul 10, 2007 at 07:52:01PM +0300, Dan Aloni wrote:
> > On Tue, Jul 10, 2007 at 08:09:04AM -0400, Neil Horman wrote:
> > > On Tue, Jul 10, 2007 at 12:18:17PM +0530, Vivek Goyal wrote:
> > > > On Fri, Jul 06, 2007 at 05:58:04PM +0300, Dan Aloni wrote:
> > > > > On Fri, Jul 06, 2007 at 03:28:14PM +0200, Bernhard Walle wrote:
> > > > > > Hello,
> > [...]
> > > > > It contains enough information in order to make a compact kernel
> > > > > dump (makedumpinfo needs to go over the struct page arrays). As
> > > > > you see, it also contains the kernel version.
> > > > >
> > > >
> > > > But this will not solve Bernhard's problem where looking at a vmcore
> > > > he wants to know which vmlinux (kernel version with time stamp) has
> > > > generated this vmcore. So adding a ELF NOTE should help.
> > > >
> > > I think an ELF note would be a fine idea.
> >
> > Okay, so here's an implemenation.
> >
> > See the attached proof-of-concept patches to the kernel-side kexec and
> > kexec-tools (might need some cleanup though). Next to follow, a patch
> > to makedumpfile. With these patches a new "LINUX" elf note generated
> > by the kernel in the format that makedumpfile expects and is being
> > passed on by the kexec util to the kdump kernel.
> >
> > As a bonus, with this patch you don't even have to compile the kernel
> > with debug information in order for the filtering to work.
> >
>
> This implementation looks interesting. No need of debug compiled
> vmlinux for dump filtering purposes. No run time vmlinux binary modifications
> as suggested by your previous mails. People can export kernel CONFIG info
> like PAGESIZE etc with the help of this ELF note and any tool which is
> processing kernel core file can benifit from this. No guesses required for
> determining the page size of crashed kernel.

I also like way of implementing it. :)

Thanks,
Bernhard