[PATCH net-next] pkt_sched: fq: use proper locking in fq_dump_stats()
From: Eric Dumazet <hidden>
Date: 2016-09-15 23:20:03
From: Eric Dumazet <redacted>
When fq is used on 32bit kernels, we need to lock the qdisc before
copying 64bit fields.
Otherwise "tc -s qdisc ..." might report bogus values.
Fixes: afe4fd062416 ("pkt_sched: fq: Fair Queue packet scheduler")
Signed-off-by: Eric Dumazet <redacted>
---
net/sched/sch_fq.c | 32 ++++++++++++++++++--------------
1 file changed, 18 insertions(+), 14 deletions(-)
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index e5458b99e09c..dc52cc10d6ed 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c@@ -823,20 +823,24 @@ nla_put_failure: static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d) { struct fq_sched_data *q = qdisc_priv(sch); - u64 now = ktime_get_ns(); - struct tc_fq_qd_stats st = { - .gc_flows = q->stat_gc_flows, - .highprio_packets = q->stat_internal_packets, - .tcp_retrans = q->stat_tcp_retrans, - .throttled = q->stat_throttled, - .flows_plimit = q->stat_flows_plimit, - .pkts_too_long = q->stat_pkts_too_long, - .allocation_errors = q->stat_allocation_errors, - .flows = q->flows, - .inactive_flows = q->inactive_flows, - .throttled_flows = q->throttled_flows, - .time_next_delayed_flow = q->time_next_delayed_flow - now, - }; + struct tc_fq_qd_stats st; + + sch_tree_lock(sch); + + st.gc_flows = q->stat_gc_flows; + st.highprio_packets = q->stat_internal_packets; + st.tcp_retrans = q->stat_tcp_retrans; + st.throttled = q->stat_throttled; + st.flows_plimit = q->stat_flows_plimit; + st.pkts_too_long = q->stat_pkts_too_long; + st.allocation_errors = q->stat_allocation_errors; + st.time_next_delayed_flow = q->time_next_delayed_flow - ktime_get_ns(); + st.flows = q->flows; + st.inactive_flows = q->inactive_flows; + st.throttled_flows = q->throttled_flows; + st.pad = 0; + + sch_tree_unlock(sch); return gnet_stats_copy_app(d, &st, sizeof(st)); }