From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Bader Subject: Re: xen-4.6: xenstored crashes during domain->interface access Date: Thu, 28 Jan 2016 09:50:37 +0100 Message-ID: <56A9D65D.2080700@canonical.com> References: <56A7513F.9040504@canonical.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2176479438823583877==" Return-path: In-Reply-To: <56A7513F.9040504@canonical.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: "xen-devel@lists.xensource.com" Cc: Bastian Blank , Ian Campbell List-Id: xen-devel@lists.xenproject.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --===============2176479438823583877== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="bxFXIX6Ac24slLMH9hbAlHNVbPObMrPMJ" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --bxFXIX6Ac24slLMH9hbAlHNVbPObMrPMJ Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 26.01.2016 11:58, Stefan Bader wrote: > Hi, >=20 > while playing around with xen-4.6 I stumbled over an odd problem and am= > wondering whether anybody has seen the same. A method to relatively qui= ckly > reproduce this for me seems to: >=20 > - Start one domU (PV or HVM does not seem to matter) > - Repeatedly call xenstore-ls a few times >=20 > I think I never got beyond 10 repeats when the xenstore-ls call suddenl= y locks > up and xenstored crashes with a SIGBUS error. In the majority of cases = (I think > I saw one different), the crash happens while accessing conn->domain->i= nterface > in tools/xenstore/xenstored_domain.c:domain_can_read(). > Looking at the corefile produced by xenstored I now got at least one ca= se where > the pointer still matches the previously mapped value. Though I think I= had also > at least one run (with less debugging added) where it seemed to be real= ly wrong. > There is more info at [1] in case someone is interested. >=20 > I need to repeat a few more times to see how consistent the whole thing= is. Does > this happen for anybody else? Any advice what I should look at (in the = sense of > gathering better data)? Just as an update and confirmation for Ian and Bastian: Debian testing is= fine. I have not dug into the specifics but its not the Xen package side at all= =2E Something in our 4.3 kernel causes this. Unfortunately without any hint i= n dmesg. But since we move to 4.4 soon and I cannot reproduce it with the p= ending 4.4 build it seems good enough to me. -Stefan >=20 > Thanks, > Stefan >=20 > [1] https://bugs.launchpad.net/ubuntu/+source/xen/+bug/1538049 >=20 --bxFXIX6Ac24slLMH9hbAlHNVbPObMrPMJ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBCgAGBQJWqdZkAAoJEOhnXe7L7s6jJi8P/1XE/s7FEDZHvbjSuE/mWHwZ /E6sL4rpboTdE+mfhNvoEa8j0z24iXCXVplFBB7ahUYxWvMZEFCUnf202vWdy31z mjwwind5Zia44TUw3k9sqk1ei8hEwN6hcy1K/+OZGfavGIQ34TTkq0LDjsZo9PbZ xP8Ry0LZX9iZgwaV8AnwtM6ue6qbTgMwtlHung2rDIcILRID5GNfyyzVSViwWSPW GmJ7FFp13TWjnNxU9wWD1KvUWQybEPHChCjZwANnIFVphfWjSG5PNWuDEKKv3wYx dSPK3XTm9uDm43anRg04p9uLMRHTgMRrHyy0gciQ1SeaFrxkvyEhojNjy8jPqSkW uF0eKFFlqQD0Ufb+F4yURl7y00RIn7P1wnGHiziWhTPfLr+wgBxOiqEfNSyBOPkp kptHlMDxmgQCWjQLyfhbf9pMnT9pqKgIC7G2MoKH0N8d/Y+ymIrTBaoEqL6WyYOP K90hykrSKH0fSa3X7S/OWsdvYVVVY560O3app57y5TJuG7gH0WXU4OQYbs2eSGvA 9mOjFjDJnbG9kVM0zF8pmpB7VKlst2AfOCNZKZkUXMwbjjjx6wQRElT/rl8IyIHq 0LQUkXWVZ6tlH31GoNHhpzgY+IDl/OASI9Rka2sqykK9XlICWqJU5R63f7mjFVbd omz3bYw3xkkkepGNGnoC =zRdo -----END PGP SIGNATURE----- --bxFXIX6Ac24slLMH9hbAlHNVbPObMrPMJ-- --===============2176479438823583877== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel --===============2176479438823583877==--