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Re: savecore can't dump

On Sun, Jun 21, 2009 at 01:11:20PM -0400, Greg A. Woods wrote:
> Not knowing the name of the booted kernel is, or would be, a bug.

Tell that to all the platforms whose firmware doesn't bother to
pass the information along to the program it loads at boot time.  Or
to people with a netbooted or embedded environment in which it's
utterly useless to know the booted kernel name as it's not in any
filesystem accessible at runtime.

> So, /dev/ksyms is all well and good and awesome even for _runtime_
> diagnostics and monitoring, but it is often absolutely useless for crash
> dumps.  Please everyone keep that in mind!

Um, no.  All the symbols needed to debug are dumped out from /dev/ksyms
at savecore time just as they'd be dumped out from the booted kernel --
neither of which will do you any good at all if you don't also happen
to have the unstripped debug kernel handy to debug with, which really
makes this "you need the running kernel to debug!" business a complete
red herring.


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