From 6239e4cd1fde091d6f0502a4af3ba5153c8a1086 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Mon, 27 May 2024 18:39:54 +0300 Subject: net/sched: taprio: make q->picos_per_byte available to fill_sched_entry() [ Upstream commit e634134180885574d1fe7aa162777ba41e7fcd5b ] 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 Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20240527153955.553333-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- .../tc-testing/tc-tests/qdiscs/taprio.json | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'tools') diff --git a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json index 12da0a939e3e..8f12f00a4f57 100644 --- a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json +++ b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json @@ -132,6 +132,28 @@ "echo \"1\" > /sys/bus/netdevsim/del_device" ] }, + { + "id": "6f62", + "name": "Add taprio Qdisc with too short interval", + "category": [ + "qdisc", + "taprio" + ], + "plugins": { + "requires": "nsPlugin" + }, + "setup": [ + "echo \"1 1 8\" > /sys/bus/netdevsim/new_device" + ], + "cmdUnderTest": "$TC qdisc add dev $ETH root handle 1: taprio num_tc 2 queues 1@0 1@1 sched-entry S 01 300 sched-entry S 02 1700 clockid CLOCK_TAI", + "expExitCode": "2", + "verifyCmd": "$TC qdisc show dev $ETH", + "matchPattern": "qdisc taprio 1: root refcnt", + "matchCount": "0", + "teardown": [ + "echo \"1\" > /sys/bus/netdevsim/del_device" + ] + }, { "id": "3e1e", "name": "Add taprio Qdisc with an invalid cycle-time", -- cgit v1.2.3