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From: Roland McGrath <roland@redhat.com>
To: ebiederm@xmission.com (Eric W. Biederman)
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Cc: Oleg Nesterov <oleg@redhat.com>, Will Drewry <wad@chromium.org>,
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Subject: Re: [PATCH][RFC] fs/exec.c: provide the correct process pid to the pipe helper
In-Reply-To: Eric W. Biederman's message of  Thursday, 16 September 2010 13:12:31 -0700 <m1zkvh4fdc.fsf@fess.ebiederm.org>
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Emacs: ballast for RAM.
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Date: Fri, 17 Sep 2010 12:08:00 -0700 (PDT)
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> That said I don't think this is a complete fix.  We also potentially
> have the same issue with the uts namespace and the user namespace.

True.

> I believe the core file holds all of this information relative to the
> process that is dying, one elf note or other so we don't need to worry
> about information loss.

That's correct (see linux/elfcore.h, pr_*id fields in prstatus and prpsinfo).

> I can imagine that it would be nice to have different core patterns
> depending on where you are in the process tree, so a container can
> do something different than the system outside of the container.  Are
> you thinking along those lines, or are you imagining something else?

I agree.  The format string being part of the pid_ns makes sense to me.  
(I don't have any ideas about the interface for setting it.)
Of course, then what would make most sense is for the pipe handler to
run in the innermost namespace that set its own format, rather than in
the global ns.


Thanks,
Roland