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Date: Mon, 27 Jun 2011 15:52:52 +0200
From: Tejun Heo <tj@kernel.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Denys Vlasenko <vda.linux@googlemail.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ptrace: make former thread ID available via
 PTRACE_GETEVENTMSG after PTRACE_EVENT_EXEC stop (v.2)
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 <20110626200442.GA16293@redhat.com>
 <20110627081139.GY30101@htj.dyndns.org>
 <20110627134713.GB3527@redhat.com>
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Hello, Oleg.

On Mon, Jun 27, 2011 at 03:47:13PM +0200, Oleg Nesterov wrote:
> > Do we want to enable this silently?  Wouldn't it be better to make it
> > dependent on PT_SEIZED?
> 
> Hmm. Not sure I understand. Why can't PTRACE_SEIZE add PT_TRACE_EXEC
> (and PT_TRACESYSGOOD) along with PT_SEIZED during attach?

I'm worrying about !PT_SEIZED case.  If we make it solely depend on
PT_TRACE_EXEC, newer kernels report the old pid while olders ones
don't and the only way to discover would be either comparing kernel
version or actually trying it - both aren't too nice.

Thanks.

-- 
tejun
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