Author: bdrewery Date: Thu Aug 13 22:06:27 2020 New Revision: 364220 URL: https://svnweb.freebsd.org/changeset/base/364220
Log: lagg: Avoid adding a port to a lagg device being destroyed. The lagg_clone_destroy() handles detach and waiting for ifconfig callers to drain already. This narrows the race for 2 panics that the tests triggered. Both were a consequence of adding a port to the lagg device after it had already detached from all of its ports. The link state task would run after lagg_clone_destroy() free'd the lagg softc. kernel:trap_fatal+0xa4 kernel:trap_pfault+0x61 kernel:trap+0x316 kernel:witness_checkorder+0x6d kernel:_sx_xlock+0x72 if_lagg.ko:lagg_port_state+0x3b kernel:if_down+0x144 kernel:if_detach+0x659 if_tap.ko:tap_destroy+0x46 kernel:if_clone_destroyif+0x1b7 kernel:if_clone_destroy+0x8d kernel:ifioctl+0x29c kernel:kern_ioctl+0x2bd kernel:sys_ioctl+0x16d kernel:amd64_syscall+0x337 kernel:trap_fatal+0xa4 kernel:trap_pfault+0x61 kernel:trap+0x316 kernel:witness_checkorder+0x6d kernel:_sx_xlock+0x72 if_lagg.ko:lagg_port_state+0x3b kernel:do_link_state_change+0x9b kernel:taskqueue_run_locked+0x10b kernel:taskqueue_run+0x49 kernel:ithread_loop+0x19c kernel:fork_exit+0x83 PR: 244168 Reviewed by: markj MFC after: 2 weeks Sponsored by: Dell EMC Differential Revision: https://reviews.freebsd.org/D25284 Modified: head/sys/net/if_lagg.c Modified: head/sys/net/if_lagg.c ============================================================================== --- head/sys/net/if_lagg.c Thu Aug 13 20:48:14 2020 (r364219) +++ head/sys/net/if_lagg.c Thu Aug 13 22:06:27 2020 (r364220) @@ -679,6 +679,9 @@ lagg_port_create(struct lagg_softc *sc, struct ifnet * return (EINVAL); } + if (sc->sc_destroying == 1) + return (ENXIO); + /* Limit the maximal number of lagg ports */ if (sc->sc_count >= LAGG_MAX_PORTS) return (ENOSPC); @@ -1190,6 +1193,8 @@ lagg_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data int count, buflen, len, error = 0, oldmtu; bzero(&rpbuf, sizeof(rpbuf)); + + /* XXX: This can race with lagg_clone_destroy. */ switch (cmd) { case SIOCGLAGG: _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"