Re: [PATCH net 2/2] selftests: tc-testing: add u32 node ID pool exhaustion test

On Thu, Aug 20, 2026 at 5:52 AM Jamal Hadi Salim <[email protected]> wrote:
>
> Add a tdc test case (7ec8) that fills the u32 node ID space with 4095
> auto-generated handles, then attempts to add a 4096th. On the fixed
> kernel the 4096th filter is rejected with ENOSPC (exit 2). On the
> unfixed kernel it silently succeeds with a duplicate handle.
>
> Fixes: e7614370d6f04 ("net_sched: use idr to allocate u32 filter handles")
> Signed-off-by: Jamal Hadi Salim <[email protected]>
> ---
>  .../tc-testing/tc-tests/filters/u32.json      | 23 +++++++++++++++++++
>  1 file changed, 23 insertions(+)
>
> diff --git a/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json b/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json
> index b2ca9d4e991b..b9019b14d05c 100644
> --- a/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json
> +++ b/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json
> @@ -353,5 +353,28 @@
>          "teardown": [
>              "$TC qdisc del dev $DEV1 parent root drr"
>          ]
> +    },
> +    {
> +        "id": "7ec8",
> +        "name": "Add u32 filter when node ID pool is exhausted (4096th filter rejected)",
> +        "category": [
> +            "filter",
> +            "u32"
> +        ],
> +        "plugins": {
> +            "requires": "nsPlugin"
> +        },
> +        "setup": [
> +            "$TC qdisc add dev $DUMMY clsact",
> +            "yes 'filter add dev $DUMMY ingress prio 1 protocol ip u32 match u8 0 0 at 0' | head -n 4095 | $TC -b -"
> +        ],
> +        "cmdUnderTest": "$TC filter add dev $DUMMY ingress prio 1 protocol ip u32 match u8 0 0 at 0",
> +        "expExitCode": "2",
> +        "verifyCmd": "$TC filter show dev $DUMMY ingress",
> +        "matchPattern": "pref 1 u32",
> +        "matchCount": "4095",
> +        "teardown": [
> +            "$TC qdisc del dev $DUMMY clsact"
> +        ]
>      }
>  ]
> --
> 2.43.0

Some of our long running tests have failed because primarily of the
tdc test in this set. Will resend with a renewed tdc test. Hopefully
my attempt at this pw-bot thing works.

--
pw-bot: cr