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Date: Fri, 6 Sep 2002 00:35:22 +0200 (CEST)
From: Ingo Molnar <mingo@elte.hu>
Reply-To: Ingo Molnar <mingo@elte.hu>
To: Daniel Jacobowitz <dan@debian.org>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>,
       Linus Torvalds <torvalds@transmeta.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [patch] ptrace-fix-2.5.33-A1
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there are two kinds of wait4 calls, one that gets the WIFSTOPPED event
from the debugged task, for this the traced task has to be in the
debugger's ->children list.

Another one is when a debugged task exits and its parent wants the exit
event. But in this case the task is untraced already, so it gets back into
the parent's ->children list.

ie. wait4 should only look at the ->children list - zombies (or traced
tasks debugged by this task) can only be there.

The only addition is that in the wait4 non-blocking case we need to look
at the traced list as well - since a non-blocking wait4 is a 'could there
be any children exiting' kind of query.

	Ingo

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