sch_qfq: fix overflow in qfq_update_start()
grp->slot_shift is between 22 and 41, so using 32bit wide variables is
probably a typo.
This could explain QFQ hangs Dave reported to me, after 2^23 packets ?
(23 = 64 - 41)
Reported-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Dave Taht <dave.taht@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index 1033434..7b03254 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -817,11 +817,11 @@
static void qfq_update_start(struct qfq_sched *q, struct qfq_class *cl)
{
unsigned long mask;
- uint32_t limit, roundedF;
+ u64 limit, roundedF;
int slot_shift = cl->grp->slot_shift;
roundedF = qfq_round_down(cl->F, slot_shift);
- limit = qfq_round_down(q->V, slot_shift) + (1UL << slot_shift);
+ limit = qfq_round_down(q->V, slot_shift) + (1ULL << slot_shift);
if (!qfq_gt(cl->F, q->V) || qfq_gt(roundedF, limit)) {
/* timestamp was stale */