Messages in this thread Patch in this message | | | From | Paolo valente <> | Subject | [PATCH BUGFIX 2/6] pkt_sched: fix the update of eligible-group sets | Date | Tue, 5 Mar 2013 19:04:58 +0100 |
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Between two invocations of make_eligible, the system virtual time may happen to grow enough that, in its binary representation, a bit with higher order than 31 flips. This happens especially with TSO/GSO. Before this fix, the mask used in make_eligible was computed as (1UL<<index_of_last_flipped_bit)-1, whose value is well defined on a 64-bit architecture, because index_of_flipped_bit <= 63, but is in general undefined on a 32-bit architecture if index_of_flipped_bit > 31. The fix just replaces 1UL with 1ULL.
Signed-off-by: Paolo Valente <paolo.valente@unimore.it> Reviewed-by: Fabio Checconi <fchecconi@gmail.com> --- net/sched/sch_qfq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c index 0f6e2db..4cbbf79 100644 --- a/net/sched/sch_qfq.c +++ b/net/sched/sch_qfq.c @@ -823,7 +823,7 @@ static void qfq_make_eligible(struct qfq_sched *q) unsigned long old_vslot = q->oldV >> q->min_slot_shift; if (vslot != old_vslot) { - unsigned long mask = (1UL << fls(vslot ^ old_vslot)) - 1; + unsigned long mask = (1ULL << fls(vslot ^ old_vslot)) - 1; qfq_move_groups(q, mask, IR, ER); qfq_move_groups(q, mask, IB, EB); } -- 1.7.9.5
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