Author: hselasky Date: Mon Oct 22 13:25:26 2018 New Revision: 339588 URL: https://svnweb.freebsd.org/changeset/base/339588
Log: Resolve deadlock between epoch(9) and various network interface SX-locks, during if_purgeaddrs(), by not allowing to hold the epoch read lock over typical network IOCTL code paths. This is a regression issue after r334305. Reviewed by: ae (network) Differential revision: https://reviews.freebsd.org/D17647 MFC after: 1 week Sponsored by: Mellanox Technologies Modified: head/sys/net/if.c Modified: head/sys/net/if.c ============================================================================== --- head/sys/net/if.c Mon Oct 22 11:58:30 2018 (r339587) +++ head/sys/net/if.c Mon Oct 22 13:25:26 2018 (r339588) @@ -964,12 +964,18 @@ if_attachdomain1(struct ifnet *ifp) void if_purgeaddrs(struct ifnet *ifp) { - struct ifaddr *ifa, *next; + struct ifaddr *ifa; - NET_EPOCH_ENTER(); - CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) { - if (ifa->ifa_addr->sa_family == AF_LINK) - continue; + while (1) { + NET_EPOCH_ENTER(); + CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { + if (ifa->ifa_addr->sa_family != AF_LINK) + break; + } + NET_EPOCH_EXIT(); + + if (ifa == NULL) + break; #ifdef INET /* XXX: Ugly!! ad hoc just for INET */ if (ifa->ifa_addr->sa_family == AF_INET) { @@ -996,7 +1002,6 @@ if_purgeaddrs(struct ifnet *ifp) IF_ADDR_WUNLOCK(ifp); ifa_free(ifa); } - NET_EPOCH_EXIT(); } /* _______________________________________________ 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"
