From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=51378 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1Q50N0-0003YI-Mn
	for qemu-devel@nongnu.org; Wed, 30 Mar 2011 14:43:55 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <gleb@redhat.com>) id 1Q50Mz-0002fl-HE
	for qemu-devel@nongnu.org; Wed, 30 Mar 2011 14:43:54 -0400
Received: from mx1.redhat.com ([209.132.183.28]:52684)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <gleb@redhat.com>) id 1Q50Mz-0002fZ-7D
	for qemu-devel@nongnu.org; Wed, 30 Mar 2011 14:43:53 -0400
Date: Wed, 30 Mar 2011 20:43:48 +0200
From: Gleb Natapov <gleb@redhat.com>
Subject: Re: [Qemu-devel] [PATCHv3] report that QEMU process was killed by
	a signal
Message-ID: <20110330184348.GB7741@redhat.com>
References: <20110315115604.GY10151@redhat.com>
	<AANLkTikOcv5EG9CSP7gyRso-E30ykGsLN6uqNPwWJQ0G@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <AANLkTikOcv5EG9CSP7gyRso-E30ykGsLN6uqNPwWJQ0G@mail.gmail.com>
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-devel@nongnu.org

On Wed, Mar 30, 2011 at 07:39:31PM +0100, Peter Maydell wrote:
> On 15 March 2011 11:56, Gleb Natapov <gleb@redhat.com> wrote:
> > Currently when rogue script kills QEMU process (using TERM/INT/HUP
> > signal) it looks indistinguishable from system shutdown. Lets report
> > that QEMU was killed and leave some clues about the killer identity.
> 
> Unfortunately this patch causes qemu to segfault when killed
> via ^C (at least on my Ubuntu maverick system). This is because
> it registers a signal handler with sigaction, but then later
> the SDL library is initialised and it reinstalls our handler
> with plain old signal:
> 
>         ohandler = signal(SIGINT, SDL_HandleSIG);
>         if ( ohandler != SIG_DFL )
>                 signal(SIGINT, ohandler);
> 
I fixed this in SDL upstream.

> This is clearly buggy but on the other hand SDL is pretty widely
> deployed and it's the default QEMU video output method, so I think
> we need to work around it :-(
> 
> The most straightforward fix is to get the signal number from
> argument one and not to bother printing the PID that killed us.
> 
For debugging purposes pid is useful. We cam register signal handler
after SDL is initialized though (if waiting for SDL update is not an
option).

--
			Gleb.