htb_dump_class_stats() and htb_offload_aggregate_stats() call gnet_stats_basic_sync_init(&cl->bstats) which is wrong on 32bit arches when syncp is cleared. Make sure to acquire qdisc spinlock and use _bstats_set() to ease future lockless dumps. Fixes: 83271586249c ("sch_htb: Stats for offloaded HTB") Signed-off-by: Eric Dumazet Cc: Maxim Mikityanskiy Cc: Tariq Toukan --- net/sched/sch_htb.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index d8ef3efbe0d5eab42c535e48d95d9005ac9682be..908b9ba9ba2efa8df396b51d437a714afc802a73 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -1293,8 +1293,6 @@ static void htb_offload_aggregate_stats(struct htb_sched *q, struct htb_class *c; unsigned int i; - gnet_stats_basic_sync_init(&cl->bstats); - for (i = 0; i < q->clhash.hashsize; i++) { hlist_for_each_entry(c, &q->clhash.hash[i], common.hnode) { struct htb_class *p = c; @@ -1313,7 +1311,7 @@ static void htb_offload_aggregate_stats(struct htb_sched *q, } } } - _bstats_update(&cl->bstats, bytes, packets); + _bstats_set(&cl->bstats, bytes, packets); } static int @@ -1340,17 +1338,21 @@ htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d) INT_MIN, INT_MAX); if (q->offload) { + spin_lock_bh(qdisc_lock(sch)); if (!cl->level) { - if (cl->leaf.q) - cl->bstats = cl->leaf.q->bstats; - else - gnet_stats_basic_sync_init(&cl->bstats); - _bstats_update(&cl->bstats, - u64_stats_read(&cl->bstats_bias.bytes), - u64_stats_read(&cl->bstats_bias.packets)); + u64 bytes = 0, packets = 0; + + if (cl->leaf.q) { + bytes = u64_stats_read(&cl->leaf.q->bstats.bytes); + packets = u64_stats_read(&cl->leaf.q->bstats.packets); + } + bytes += u64_stats_read(&cl->bstats_bias.bytes); + packets += u64_stats_read(&cl->bstats_bias.packets); + _bstats_set(&cl->bstats, bytes, packets); } else { htb_offload_aggregate_stats(q, cl); } + spin_unlock_bh(qdisc_lock(sch)); } if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 || -- 2.54.0.563.g4f69b47b94-goog