5.10-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit c5f1dde7f731e7bf2e7c169ca42cb4989fc2f8b9 ]
Instead of relying on RTNL, ets_dump() can use READ_ONCE() annotations, paired with WRITE_ONCE() ones in ets_change().
Signed-off-by: Eric Dumazet edumazet@google.com Reviewed-by: Simon Horman horms@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: 87c6efc5ce9c ("net/sched: ets: use old 'nbands' while purging unused classes") Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/sch_ets.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)
--- a/net/sched/sch_ets.c +++ b/net/sched/sch_ets.c @@ -664,7 +664,7 @@ static int ets_qdisc_change(struct Qdisc
sch_tree_lock(sch);
- q->nbands = nbands; + WRITE_ONCE(q->nbands, nbands); for (i = nstrict; i < q->nstrict; i++) { if (q->classes[i].qdisc->q.qlen) { list_add_tail(&q->classes[i].alist, &q->active); @@ -676,11 +676,11 @@ static int ets_qdisc_change(struct Qdisc list_del_init(&q->classes[i].alist); qdisc_purge_queue(q->classes[i].qdisc); } - q->nstrict = nstrict; + WRITE_ONCE(q->nstrict, nstrict); memcpy(q->prio2band, priomap, sizeof(priomap));
for (i = 0; i < q->nbands; i++) - q->classes[i].quantum = quanta[i]; + WRITE_ONCE(q->classes[i].quantum, quanta[i]);
for (i = oldbands; i < q->nbands; i++) { q->classes[i].qdisc = queues[i]; @@ -694,7 +694,7 @@ static int ets_qdisc_change(struct Qdisc for (i = q->nbands; i < oldbands; i++) { qdisc_put(q->classes[i].qdisc); q->classes[i].qdisc = NULL; - q->classes[i].quantum = 0; + WRITE_ONCE(q->classes[i].quantum, 0); q->classes[i].deficit = 0; memset(&q->classes[i].bstats, 0, sizeof(q->classes[i].bstats)); memset(&q->classes[i].qstats, 0, sizeof(q->classes[i].qstats)); @@ -751,6 +751,7 @@ static int ets_qdisc_dump(struct Qdisc * struct ets_sched *q = qdisc_priv(sch); struct nlattr *opts; struct nlattr *nest; + u8 nbands, nstrict; int band; int prio; int err; @@ -763,21 +764,22 @@ static int ets_qdisc_dump(struct Qdisc * if (!opts) goto nla_err;
- if (nla_put_u8(skb, TCA_ETS_NBANDS, q->nbands)) + nbands = READ_ONCE(q->nbands); + if (nla_put_u8(skb, TCA_ETS_NBANDS, nbands)) goto nla_err;
- if (q->nstrict && - nla_put_u8(skb, TCA_ETS_NSTRICT, q->nstrict)) + nstrict = READ_ONCE(q->nstrict); + if (nstrict && nla_put_u8(skb, TCA_ETS_NSTRICT, nstrict)) goto nla_err;
- if (q->nbands > q->nstrict) { + if (nbands > nstrict) { nest = nla_nest_start(skb, TCA_ETS_QUANTA); if (!nest) goto nla_err;
- for (band = q->nstrict; band < q->nbands; band++) { + for (band = nstrict; band < nbands; band++) { if (nla_put_u32(skb, TCA_ETS_QUANTA_BAND, - q->classes[band].quantum)) + READ_ONCE(q->classes[band].quantum))) goto nla_err; }
@@ -789,7 +791,8 @@ static int ets_qdisc_dump(struct Qdisc * goto nla_err;
for (prio = 0; prio <= TC_PRIO_MAX; prio++) { - if (nla_put_u8(skb, TCA_ETS_PRIOMAP_BAND, q->prio2band[prio])) + if (nla_put_u8(skb, TCA_ETS_PRIOMAP_BAND, + READ_ONCE(q->prio2band[prio]))) goto nla_err; }