X-Recipient:	archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status:	No, hits=-1.9 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,RCVD_IN_HOSTKARMA_YE
X-Spam-Check-By:	sourceware.org
X-Mail-Handler:	Dyn Standard SMTP by Dyn
X-Report-Abuse-To:	abuse AT dyndns DOT com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information)
X-MHO-User:	U2FsdGVkX19u2KgE3o2it9VZ4WYzgIY/
Date:	Thu, 16 Aug 2012 14:32:16 -0400
From:	Christopher Faylor <cgf-use-the-mailinglist-please AT cygwin DOT com>
To:	cygwin AT cygwin DOT com
Subject:	Re: Cygwin crashes in kill_pgrp, _pinfo truncation issue.
Message-ID:	<20120816183216.GA16862@ednor.casa.cgf.cx>
Reply-To:	cygwin AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
References:	<CACgPhYoVzcUEH-w1Lx5zgwbY-Jic67sH=gwy2qGiqMrv519sOA AT mail DOT gmail DOT com>
MIME-Version:	1.0
In-Reply-To:	<CACgPhYoVzcUEH-w1Lx5zgwbY-Jic67sH=gwy2qGiqMrv519sOA@mail.gmail.com>
User-Agent:	Mutt/1.5.20 (2009-06-14)
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Unsubscribe:	<mailto:cygwin-unsubscribe-archive-cygwin=delorie DOT com AT cygwin DOT com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com

On Thu, Aug 16, 2012 at 08:20:37PM +0400, Andrey Khalyavin wrote:
>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 updated core libraries from 20120803 snapshot to 20120815 snapshot
>and now bash crashes when I execute rm -rf dir. Reproducibility is
>strange. It crashed for hours when I entered
>cd /tmp
>mkdir a
>rm -rf a
>commands but now suddenly stopped crashing in this case.
>It is still crashes on rm -rf in the real script we use though.
>
>Crash happens in setup_handler function on line
>	  HANDLE hth = (HANDLE) *tls;
>because tls->tid equals to zero. Definition of this operation is in
>sygtls.h: operator HANDLE () const {return tid->win32_obj_id;}.
>setup_handler is called from sigpacket::process which in turn
>called from wait_sig. Signal number is 20, signal code is 28.
>All fields of tls structure are zero with exception stacklock equal
>to 1 and stackptr equal to address of tls->stack.

Sounds like a race between thread creation and signal handling.  I have
added some defensive code in the latest snapshot.

cgf

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple

- Raw text -