Date: Wed, 5 Oct 2005 13:55:15 -0700 From: Brooks Davis <brooks@one-eyed-alien.net> To: Pawel Jakub Dawidek <pjd@FreeBSD.org> Cc: Brooks Davis <brooks@FreeBSD.org>, FreeBSD Current <current@FreeBSD.org>, Andrew Thompson <thompsa@FreeBSD.org> Subject: Re: panic: ifc_free_unit: bit is already cleared Message-ID: <20051005205515.GA30350@odin.ac.hmc.edu> In-Reply-To: <20051005203639.GA20552@garage.freebsd.pl> References: <20051005024903.GA72743@heff.fud.org.nz> <20051005203639.GA20552@garage.freebsd.pl>
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--pWyiEgJYm5f9v55/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Oct 05, 2005 at 10:36:39PM +0200, Pawel Jakub Dawidek wrote: > On Wed, Oct 05, 2005 at 03:49:03PM +1300, Andrew Thompson wrote: > +> Hi, > +>=20 > +> I have found a repeatable panic with network device cloning, unfortuna= tly I am > +> unable to dump on this box. This is sparc64 with a 2 day old current. >=20 > The order is wrong in vlan_modevent(). >=20 > if_clone_detach() is freeing ifc_units field, so ifc_free_unit() should n= ot > be called after that. >=20 > This patch should fix the problem: >=20 > http://people.freebsd.org/~pjd/patches/if_vlan.c.patch Yes. This does introduce a race in that a new interface could be created between the vlan_clone_destroy loop and the call to if_clone_detach. It's going to be hard to trigger, but it probably should be fixed. Since cloning isn't performance critical, I think adding a dead flag to the clone structure and failing all attempts once the flag is set. -- Brooks --=20 Any statement of the form "X is the one, true Y" is FALSE. PGP fingerprint 655D 519C 26A7 82E7 2529 9BF0 5D8E 8BE9 F238 1AD4 --pWyiEgJYm5f9v55/ Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQFDRD2zXY6L6fI4GtQRAkYcAJ95L5mfgqtdndQk2+/t94eJb4iEwwCff6Og 4NbDvw6k5op2qpWyV7D/jBQ= =vrdy -----END PGP SIGNATURE----- --pWyiEgJYm5f9v55/--
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