[Crash-utility] user-space enhancements

[Dave Anderson]

----- "James Bradshaw" <jbradsha at enterasys.com> wrote:

> Right. To be able to examine user space, you'd have to build an elf
> core file by processing the desired task structure in the kdump file,
> find all the user pages, etc.--essentially what elf_core_dump() does
> in a running kernel. Then you could use gdb offline or the embedded
> gdb.

Yep, that would be pretty cool... "gdb offline" that is.  

I still don't think it makes sense to do anything on the user core
file from the embedded gdb, given it's been wired/hacked to work solely
as a crash utility slave.

I envision a command that would work something like, for example,
for PID 24677:

  crash> core 24677
  core.24677 created
  crash>

where 24677 is the PID.  As a template for gathering the core data,
the "vm -p" command shows you where all of the user pages are, and
the "bt" kernel entry point gives you the "last-known" register set.
Seems like it could work...

> I understand your desire not to burden crash with user space stuff,
> although the extensions facility seems to provide a mechanism for
> cleanly excluding such functionality from the standard configuration.
> Just a thought.

Absolutely -- that's precisely what it's there for.  

But for that matter, after it's working nicely as an extension, 
and if it can be cleanly, reliably and maintainably (word?) moved
into the base sources, I'm all for it.  

Thanks,
  Dave