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Date: Thu, 23 Aug 2012 14:29:21 +0400
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Subject: Re: Cygwin crashes in kill_pgrp, _pinfo truncation issue.
From: Andrey Khalyavin <halyavin AT google DOT com>
To: cygwin AT cygwin DOT com
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On Wed, 15 Aug 2012 10:11:16 -0400, Christopher Faylor wrote:
>On Wed, Aug 15, 2012 at 04:54:42PM +0400, Andrey Khalyavin wrote:
>>I finally got a cygwin crash dump from our build bots. It shows, that
>>cygwin1.dll crashes in kill_pgrp function on line:
>>	  (pid > 1 && p->pgid != pid) ||
>>where p is a pointer to _pinfo. This function enumerates all _pinfo's
>>and executes this line for all of them which pass p->exists() check.
>>In crash dump p points to _pinfo that has process_state equal to
>>PID_IN_USE | PID_EXECED.
>
>Thanks for tracking this down.  I've added a check for "execed" to
>_pinfo::exists.
>
>cgf

I got two more crash dumps from our bots running 20120816 snapshot.
Both of them crashed in this place. process_state equals to
PID_IN_USE | PIE_EXECED and your new check in _pinfo::exist is really there.
So the race condition on process_state field does happens in practice.

Andrey Khalyavin

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