[PATCH net 7/7] selftests/xsk: account invalid multi-buffer Tx descriptors
From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Date: 2026-06-23 13:33:35
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest, xdp sockets (af_xdp) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Linus Torvalds, Magnus Karlsson, Maciej Fijalkowski
Invalid descriptors in the middle of a multi-buffer packet still belong to the packet being consumed from the Tx ring. The tests should therefore count the whole invalid packet as outstanding in verbatim mode, even though the packet must not be expected on the Rx side. Make fragment counting follow the packet boundary instead of stopping at the first invalid fragment. Update custom stream generation so invalid middle fragments terminate the generated Rx packet while Tx accounting still covers all descriptors consumed from the invalid multi-buffer packet. Also add explicit end fragments after invalid middle descriptors. This exercises the kernel drain logic and verifies that subsequent valid packets are not interpreted as continuations of the invalid packet. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> --- .../selftests/bpf/prog_tests/test_xsk.c | 24 ++++++++++++------- 1 file changed, 15 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/test_xsk.c b/tools/testing/selftests/bpf/prog_tests/test_xsk.c
index de1e63c3fdf6..d8a1c0d40e5a 100644
--- a/tools/testing/selftests/bpf/prog_tests/test_xsk.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_xsk.c@@ -433,14 +433,14 @@ static u32 pkt_nb_frags(u32 frame_size, struct pkt_stream *pkt_stream, struct pk } /* Search for the end of the packet in verbatim mode */ - if (!pkt_continues(pkt->options) || !pkt->valid) + if (!pkt_continues(pkt->options)) return nb_frags; next_frag = pkt_stream->current_pkt_nb; pkt++; while (next_frag++ < pkt_stream->nb_pkts) { nb_frags++; - if (!pkt_continues(pkt->options) || !pkt->valid) + if (!pkt_continues(pkt->options)) break; pkt++; }
@@ -671,11 +671,11 @@ static struct pkt_stream *__pkt_stream_generate_custom(struct ifobject *ifobj, s if (!frame->valid || !pkt_continues(frame->options)) payload++; } else { - if (frame->valid) + if (frame->valid) { len += frame->len; - if (frame->valid && pkt_continues(frame->options)) - continue; - + if (pkt_continues(frame->options)) + continue; + } pkt->pkt_nb = pkt_nb; pkt->len = len; pkt->valid = frame->valid;
@@ -1214,6 +1214,7 @@ static int __send_pkts(struct ifobject *ifobject, struct xsk_socket_info *xsk, b for (i = 0; i < xsk->batch_size; i++) { struct pkt *pkt = pkt_stream_get_next_tx_pkt(pkt_stream); u32 nb_frags_left, nb_frags, bytes_written = 0; + struct pkt *first_pkt = pkt; if (!pkt) break;
@@ -1258,6 +1259,8 @@ static int __send_pkts(struct ifobject *ifobject, struct xsk_socket_info *xsk, b if (pkt && pkt->valid) { valid_pkts++; valid_frags += nb_frags; + } else if (pkt_stream->verbatim && pkt_continues(first_pkt->options)) { + valid_frags += nb_frags; } }
@@ -2104,13 +2107,16 @@ int testapp_invalid_desc_mb(struct test_spec *test) {0, 0, 0, false, 0}, /* Invalid address in the second frame */ {0, XSK_UMEM__LARGE_FRAME_SIZE, 0, false, XDP_PKT_CONTD}, - {umem_sz, XSK_UMEM__LARGE_FRAME_SIZE, 0, false, XDP_PKT_CONTD}, + {umem_sz * 2, XSK_UMEM__LARGE_FRAME_SIZE, 0, false, XDP_PKT_CONTD}, + {0, MIN_PKT_SIZE, 0, false, 0}, /* Invalid len in the middle */ {0, XSK_UMEM__LARGE_FRAME_SIZE, 0, false, XDP_PKT_CONTD}, {0, XSK_UMEM__INVALID_FRAME_SIZE, 0, false, XDP_PKT_CONTD}, + {0, MIN_PKT_SIZE, 0, false, 0}, /* Invalid options in the middle */ {0, XSK_UMEM__LARGE_FRAME_SIZE, 0, false, XDP_PKT_CONTD}, {0, XSK_UMEM__LARGE_FRAME_SIZE, 0, false, XSK_DESC__INVALID_OPTION}, + {0, MIN_PKT_SIZE, 0, false, 0}, /* Transmit 2 frags, receive 3 */ {0, XSK_UMEM__MAX_FRAME_SIZE, 0, true, XDP_PKT_CONTD}, {0, XSK_UMEM__MAX_FRAME_SIZE, 0, true, 0},
@@ -2122,8 +2128,8 @@ int testapp_invalid_desc_mb(struct test_spec *test) if (umem->unaligned_mode) { /* Crossing a chunk boundary allowed */ - pkts[12].valid = true; - pkts[13].valid = true; + pkts[15].valid = true; + pkts[16].valid = true; } test->mtu = MAX_ETH_JUMBO_SIZE;
--
2.43.0