diff options
| author | Vladimir Oltean | 2024-05-27 18:39:54 +0300 |
|---|---|---|
| committer | Jakub Kicinski | 2024-05-28 19:46:41 -0700 |
| commit | e634134180885574d1fe7aa162777ba41e7fcd5b (patch) | |
| tree | 89cb009d838da80ef4b5b52b8aeb903f84c3e556 /net/sched | |
| parent | 56a5cf538c3f2d935b0d81040a8303b6e7fc5fd8 (diff) | |
net/sched: taprio: make q->picos_per_byte available to fill_sched_entry()
In commit b5b73b26b3ca ("taprio: Fix allowing too small intervals"), a
comparison of user input against length_to_duration(q, ETH_ZLEN) was
introduced, to avoid RCU stalls due to frequent hrtimers.
The implementation of length_to_duration() depends on q->picos_per_byte
being set for the link speed. The blamed commit in the Fixes: tag has
moved this too late, so the checks introduced above are ineffective.
The q->picos_per_byte is zero at parse_taprio_schedule() ->
parse_sched_list() -> parse_sched_entry() -> fill_sched_entry() time.
Move the taprio_set_picos_per_byte() call as one of the first things in
taprio_change(), before the bulk of the netlink attribute parsing is
done. That's because it is needed there.
Add a selftest to make sure the issue doesn't get reintroduced.
Fixes: 09dbdf28f9f9 ("net/sched: taprio: fix calculation of maximum gate durations")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240527153955.553333-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/sched')
| -rw-r--r-- | net/sched/sch_taprio.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 1ab17e8a7260..118915055360 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1848,6 +1848,9 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, } q->flags = taprio_flags; + /* Needed for length_to_duration() during netlink attribute parsing */ + taprio_set_picos_per_byte(dev, q); + err = taprio_parse_mqprio_opt(dev, mqprio, extack, q->flags); if (err < 0) return err; @@ -1907,7 +1910,6 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, if (err < 0) goto free_sched; - taprio_set_picos_per_byte(dev, q); taprio_update_queue_max_sdu(q, new_admin, stab); if (FULL_OFFLOAD_IS_ENABLED(q->flags)) |