From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:44041) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QXSqL-0005wM-S8 for qemu-devel@nongnu.org; Fri, 17 Jun 2011 02:47:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QXSqK-0001n7-RX for qemu-devel@nongnu.org; Fri, 17 Jun 2011 02:47:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:15499) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QXSqK-0001mn-Jm for qemu-devel@nongnu.org; Fri, 17 Jun 2011 02:47:48 -0400 Date: Fri, 17 Jun 2011 12:17:36 +0530 From: Amit Shah Message-ID: <20110617064736.GA18513@amit-x200.redhat.com> References: <20110616133849.02fb4bea@doriath> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110616133849.02fb4bea@doriath> Subject: Re: [Qemu-devel] [PATCH] virtio-serial: Fix segfault on guest boot List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luiz Capitulino Cc: qemu-devel , Markus Armbruster , mdroth@linux.vnet.ibm.com On (Thu) 16 Jun 2011 [13:38:49], Luiz Capitulino wrote: > If I start qemu with: > > # qemu -hda disks/test.img -enable-kvm -m 1G -snapshot \ > -device virtio-serial \ > -chardev socket,host=localhost,port=1234,server,nowait,id=foo \ > -device virtserialport,chardev=foo,name=org.qemu.guest_agent > > I get a segfault when booting a Fedora 14 guest. The backtrace says: > > Program terminated with signal 11, Segmentation fault. > #0 0x0000000000420850 in handle_control_message (vser=0x3732bd0, buf=0x2c173e0, len=8) at /home/lcapitulino/src/qmp-unstable/hw/virtio-serial-bus.c:335 > 335 info = DO_UPCAST(VirtIOSerialPortInfo, qdev, port->dev.info); Strange, I've not seen it so far in my testing (neither in the daily test runs of the virtio-serial testsuite). > I've also bisected this and git points out to commit: > > commit a15bb0d6a981de749452a5180fc8084d625671da > Author: Markus Armbruster > Date: Wed May 25 14:21:13 2011 +0200 > > virtio-serial: Drop redundant VirtIOSerialPort member info > > I think what's happening is that the device is not initialized on a > VIRTIO_CONSOLE_DEVICE_READY event. Moving the DO_UPCAST() call to > the other events fixes the problem to me. > > Signed-off-by: Luiz Capitulino > --- > hw/virtio-serial-bus.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c > index 9a12104..579f676 100644 > --- a/hw/virtio-serial-bus.c > +++ b/hw/virtio-serial-bus.c > @@ -332,8 +332,6 @@ static void handle_control_message(VirtIOSerial *vser, void *buf, size_t len) > if (!port && cpkt.event != VIRTIO_CONSOLE_DEVICE_READY) > return; > > - info = DO_UPCAST(VirtIOSerialPortInfo, qdev, port->dev.info); > - Ah - this missed the !port check. It should be possible to do this in a 'if (port)' block instead of replicating in the individual case statements. Thanks for the debugging and patch; please update with the above and I'll apply it to the virtio-serial tree. Amit