On 13/06/2023 18:54, Vladimir Oltean wrote:
> Check that the "Can only be attached as root qdisc" error message from
> taprio is effective by attempting to attach it to a class of another
> taprio qdisc. That operation should fail.
>
> In the bug that was squashed by change "net/sched: taprio: try again to
> report q->qdiscs[] to qdisc_leaf()", grafting a child taprio to a root
> software taprio would be misinterpreted as a change() to the root
> taprio. Catch this by looking at whether the base-time of the root
> taprio has changed to follow the base-time of the child taprio,
> something which should have absolutely never happened assuming correct
> semantics.
>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
> ---
> v1->v2: patch is new
>
> .../tc-testing/tc-tests/qdiscs/taprio.json | 48 +++++++++++++++++++
> 1 file changed, 48 insertions(+)
>
> 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 a44455372646..58d4d97f4499 100644
> --- a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json
> +++ b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json
> @@ -131,5 +131,53 @@
> "teardown": [
> "echo \"1\" > /sys/bus/netdevsim/del_device"
> ]
> + },
> + {
> + "id": "39b4",
> + "name": "Reject grafting taprio as child qdisc of software taprio",
> + "category": [
> + "qdisc",
> + "taprio"
> + ],
> + "plugins": {
> + "requires": "nsPlugin"
> + },
> + "setup": [
> + "echo \"1 1 8\" > /sys/bus/netdevsim/new_device",
> + "$TC qdisc replace dev $ETH handle 8001: parent root stab overhead 24 taprio num_tc 8 map 0 1 2 3 4 5 6 7 queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 base-time 0 sched-entry S ff 20000000 clockid CLOCK_TAI"
> + ],
> + "cmdUnderTest": "$TC qdisc replace dev $ETH parent 8001:7 taprio num_tc 8 map 0 1 2 3 4 5 6 7 queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 base-time 200 sched-entry S ff 20000000 clockid CLOCK_TAI",
> + "expExitCode": "2",
> + "verifyCmd": "$TC -j qdisc show dev $ETH root | jq '.[].options.base_time'",
> + "matchPattern": "0",
> + "matchCount": "1",
> + "teardown": [
> + "$TC qdisc del dev $ETH root",
> + "echo \"1\" > /sys/bus/netdevsim/del_device"
> + ]
> + },
> + {
> + "id": "e8a1",
> + "name": "Reject grafting taprio as child qdisc of offloaded taprio",
> + "category": [
> + "qdisc",
> + "taprio"
> + ],
> + "plugins": {
> + "requires": "nsPlugin"
> + },
> + "setup": [
> + "echo \"1 1 8\" > /sys/bus/netdevsim/new_device",
> + "$TC qdisc replace dev $ETH handle 8001: parent root stab overhead 24 taprio num_tc 8 map 0 1 2 3 4 5 6 7 queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 base-time 0 sched-entry S ff 20000000 flags 0x2"
> + ],
> + "cmdUnderTest": "$TC qdisc replace dev $ETH parent 8001:7 taprio num_tc 8 map 0 1 2 3 4 5 6 7 queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 base-time 200 sched-entry S ff 20000000 flags 0x2",
> + "expExitCode": "2",
> + "verifyCmd": "$TC -j qdisc show dev $ETH root | jq '.[].options.base_time'",
> + "matchPattern": "0",
> + "matchCount": "1",
> + "teardown": [
> + "$TC qdisc del dev $ETH root",
> + "echo \"1\" > /sys/bus/netdevsim/del_device"
> + ]
> }
> ]