Date: Tue, 7 Dec 2010 22:43:29 +0000 (UTC) From: "Bjoern A. Zeeb" <bz@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r216277 - head/sys/netinet6 Message-ID: <201012072243.oB7MhTZM082406@svn.freebsd.org>
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Author: bz Date: Tue Dec 7 22:43:29 2010 New Revision: 216277 URL: http://svn.freebsd.org/changeset/base/216277 Log: Loosen the locking in nd6-free() again after r216022 to avoid a LOR and a recursed lock. Reported by: delphij Tested by: delphij PR: kern/148857 MFC After: 3 days Modified: head/sys/netinet6/nd6.c Modified: head/sys/netinet6/nd6.c ============================================================================== --- head/sys/netinet6/nd6.c Tue Dec 7 22:43:25 2010 (r216276) +++ head/sys/netinet6/nd6.c Tue Dec 7 22:43:29 2010 (r216277) @@ -1053,15 +1053,6 @@ nd6_free(struct llentry *ln, int gc) return (next); } - if (ln->ln_router || dr) { - /* - * rt6_flush must be called whether or not the neighbor - * is in the Default Router List. - * See a corresponding comment in nd6_na_input(). - */ - rt6_flush(&L3_ADDR_SIN6(ln)->sin6_addr, ifp); - } - if (dr) { /* * Unreachablity of a router might affect the default @@ -1077,8 +1068,28 @@ nd6_free(struct llentry *ln, int gc) * or the entry itself will be deleted. */ ln->ln_state = ND6_LLINFO_INCOMPLETE; + } + + if (ln->ln_router || dr) { /* + * We need to unlock to avoid a LOR with rt6_flush() with the + * rnh and for the calls to pfxlist_onlink_check() and + * defrouter_select() in the block further down for calls + * into nd6_lookup(). We still hold a ref. + */ + LLE_WUNLOCK(ln); + + /* + * rt6_flush must be called whether or not the neighbor + * is in the Default Router List. + * See a corresponding comment in nd6_na_input(). + */ + rt6_flush(&L3_ADDR_SIN6(ln)->sin6_addr, ifp); + } + + if (dr) { + /* * Since defrouter_select() does not affect the * on-link determination and MIP6 needs the check * before the default router selection, we perform @@ -1087,13 +1098,13 @@ nd6_free(struct llentry *ln, int gc) pfxlist_onlink_check(); /* - * Refresh default router list. Have to unlock as - * it calls into nd6_lookup(), still holding a ref. + * Refresh default router list. */ - LLE_WUNLOCK(ln); defrouter_select(); - LLE_WLOCK(ln); } + + if (ln->ln_router || dr) + LLE_WLOCK(ln); } /*
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