From ff25cdd646326ab0ebb33402740d6cd4386a45f4 Mon Sep 17 00:00:00 2001 From: ume Date: Thu, 12 Nov 2009 14:48:36 +0000 Subject: - We are not guaranteed that we're not dropping a reference that we did not add. Call LLE_REMREF() only when callout_stop() actually canceled a pending callout. - callout_reset() may cancel a pending callout. When callout_reset() canceled a pending callout, call LLE_REMREF() to drop a reference for the canceled callout. MFC after: 1 week --- sys/netinet6/nd6.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c index 3225b82..575ff25 100644 --- a/sys/netinet6/nd6.c +++ b/sys/netinet6/nd6.c @@ -439,31 +439,27 @@ skip1: void nd6_llinfo_settimer_locked(struct llentry *ln, long tick) { + int canceled; + if (tick < 0) { ln->la_expire = 0; ln->ln_ntick = 0; - callout_stop(&ln->ln_timer_ch); - /* - * XXX - do we know that there is - * callout installed? i.e. are we - * guaranteed that we're not dropping - * a reference that we did not add? - * KMM - */ - LLE_REMREF(ln); + canceled = callout_stop(&ln->ln_timer_ch); } else { ln->la_expire = time_second + tick / hz; LLE_ADDREF(ln); if (tick > INT_MAX) { ln->ln_ntick = tick - INT_MAX; - callout_reset(&ln->ln_timer_ch, INT_MAX, + canceled = callout_reset(&ln->ln_timer_ch, INT_MAX, nd6_llinfo_timer, ln); } else { ln->ln_ntick = 0; - callout_reset(&ln->ln_timer_ch, tick, + canceled = callout_reset(&ln->ln_timer_ch, tick, nd6_llinfo_timer, ln); } } + if (canceled) + LLE_REMREF(ln); } void @@ -1048,6 +1044,9 @@ nd6_free(struct llentry *ln, int gc) else nd6_llinfo_settimer(ln, (long)V_nd6_gctimer * hz); splx(s); + LLE_WLOCK(ln); + LLE_REMREF(ln); + LLE_WUNLOCK(ln); return (LIST_NEXT(ln, lle_next)); } -- cgit v1.1