diff options
| author | Xiang Mei <xmei5@asu.edu> | 2026-03-26 13:43:10 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-03-27 20:41:11 -0700 |
| commit | 5d17af9eb2dd3de6846ed344c883de7812e6cc09 (patch) | |
| tree | c9190a9c7931154790385837aac1ccfd389f7409 /tools/testing/selftests | |
| parent | 4576100b8cd03118267513cafacde164b498b322 (diff) | |
selftests/tc-testing: add test for HFSC divide-by-zero in rtsc_min()
Add a regression test for the divide-by-zero in rtsc_min() triggered
when m2sm() converts a large m1 value (e.g. 32gbit) to a u64 scaled
slope reaching 2^32. rtsc_min() stores the difference of two such u64
values (sm1 - sm2) in a u32 variable `dsm`, truncating 2^32 to zero
and causing a divide-by-zero oops in the concave-curve intersection
path. The test configures an HFSC class with m1=32gbit d=1ms m2=0bit,
sends a packet to activate the class, waits for it to drain and go
idle, then sends another packet to trigger reactivation through
rtsc_min().
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20260326204310.1549327-2-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'tools/testing/selftests')
| -rw-r--r-- | tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json b/tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json index 6a39640aa2a8..1e5efb2a31eb 100644 --- a/tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json +++ b/tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json @@ -1111,5 +1111,30 @@ "teardown": [ "$TC qdisc del dev $DUMMY root handle 1:" ] + }, + { + "id": "a3d7", + "name": "HFSC with large m1 - no divide-by-zero on class reactivation", + "category": [ + "qdisc", + "hfsc" + ], + "plugins": { + "requires": "nsPlugin" + }, + "setup": [ + "$TC qdisc replace dev $DUMMY root handle 1: hfsc default 1", + "$TC class replace dev $DUMMY parent 1: classid 1:1 hfsc rt m1 32gbit d 1ms m2 0bit ls m1 32gbit d 1ms m2 0bit", + "ping -I$DUMMY -f -c1 -s64 -W1 10.10.10.1 || true", + "sleep 1" + ], + "cmdUnderTest": "ping -I$DUMMY -f -c1 -s64 -W1 10.10.10.1 || true", + "expExitCode": "0", + "verifyCmd": "$TC qdisc show dev $DUMMY", + "matchPattern": "qdisc hfsc 1: root", + "matchCount": "1", + "teardown": [ + "$TC qdisc del dev $DUMMY handle 1: root" + ] } ] |