[PATCH bpf-next v3 09/14] selftests/bpf: test_xsk: Don't exit immediately when workers fail

Bastien Curutchet (eBPF Foundation)
2025-09-04T10:11:42Z

TX and RX workers can fail in many places. These failures trigger a call
to exit_with_error() which exits the program immediately. It prevents the
following tests from running and isn't compliant with the CI.

Add return value to functions that can fail.
Handle failures more smoothly through report_failure().

Signed-off-by: Bastien Curutchet (eBPF Foundation) <bastien.curutchet@bootlin.com>
---
tools/testing/selftests/bpf/test_xsk.c | 110 +++++++++++++++++++++++----------
1 file changed, 76 insertions(+), 34 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_xsk.c b/tools/testing/selftests/bpf/test_xsk.c
index adefb50e2b08d923c412b17d7d31300f7eb7a0e7..bd26da9693ee501b3f754da5cf555aaee5c83af3 100644
--- a/tools/testing/selftests/bpf/test_xsk.c
+++ b/tools/testing/selftests/bpf/test_xsk.c
@@ -142,24 +142,26 @@ static void umem_reset_alloc(struct xsk_umem_info *umem)
umem->next_buffer = 0;
}

-static void enable_busy_poll(struct xsk_socket_info *xsk)
+static int enable_busy_poll(struct xsk_socket_info *xsk)
{
int sock_opt;

sock_opt = 1;
if (setsockopt(xsk_socket__fd(xsk->xsk), SOL_SOCKET, SO_PREFER_BUSY_POLL,
(void *)&sock_opt, sizeof(sock_opt)) < 0)
- exit_with_error(errno);
+ return -errno;

sock_opt = 20;
if (setsockopt(xsk_socket__fd(xsk->xsk), SOL_SOCKET, SO_BUSY_POLL,
(void *)&sock_opt, sizeof(sock_opt)) < 0)
- exit_with_error(errno);
+ return -errno;

sock_opt = xsk->batch_size;
if (setsockopt(xsk_socket__fd(xsk->xsk), SOL_SOCKET, SO_BUSY_POLL_BUDGET,
(void *)&sock_opt, sizeof(sock_opt)) < 0)
- exit_with_error(errno);
+ return -errno;
+
+ return 0;
}

int xsk_configure_socket(struct xsk_socket_info *xsk, struct xsk_umem_info *umem,
@@ -769,7 +771,7 @@ static bool is_metadata_correct(struct pkt *pkt, void *buffer, u64 addr)
return true;
}

-static bool is_adjust_tail_supported(struct xsk_xdp_progs *skel_rx)
+static int is_adjust_tail_supported(struct xsk_xdp_progs *skel_rx, bool *supported)
{
struct bpf_map *data_map;
int adjust_value = 0;
@@ -779,19 +781,21 @@ static bool is_adjust_tail_supported(struct xsk_xdp_progs *skel_rx)
data_map = bpf_object__find_map_by_name(skel_rx->obj, "xsk_xdp_.bss");
if (!data_map || !bpf_map__is_internal(data_map)) {
ksft_print_msg("Error: could not find bss section of XDP program\n");
- exit_with_error(errno);
+ return -EINVAL;
}

ret = bpf_map_lookup_elem(bpf_map__fd(data_map), &key, &adjust_value);
if (ret) {
ksft_print_msg("Error: bpf_map_lookup_elem failed with error %d\n", ret);
- exit_with_error(errno);
+ return ret;
}

/* Set the 'adjust_value' variable to -EOPNOTSUPP in the XDP program if the adjust_tail
* helper is not supported. Skip the adjust_tail test case in this scenario.
*/
- return adjust_value != -EOPNOTSUPP;
+ *supported = adjust_value != -EOPNOTSUPP;
+
+ return 0;
}

static bool is_frag_valid(struct xsk_umem_info *umem, u64 addr, u32 len, u32 expected_pkt_nb,
@@ -1443,7 +1447,7 @@ static int validate_tx_invalid_descs(struct ifobject *ifobject)
return TEST_PASS;
}

-static void xsk_configure(struct test_spec *test, struct ifobject *ifobject,
+static int xsk_configure(struct test_spec *test, struct ifobject *ifobject,
struct xsk_umem_info *umem, bool tx)
{
int i, ret;
@@ -1460,24 +1464,34 @@ static void xsk_configure(struct test_spec *test, struct ifobject *ifobject,

/* Retry if it fails as xsk_socket__create() is asynchronous */
if (ctr >= SOCK_RECONF_CTR)
- exit_with_error(-ret);
+ return ret;
usleep(USLEEP_MAX);
}
- if (ifobject->busy_poll)
- enable_busy_poll(&ifobject->xsk_arr[i]);
+ if (ifobject->busy_poll) {
+ ret = enable_busy_poll(&ifobject->xsk_arr[i]);
+ if (ret)
+ return ret;
+ }
}
+
+ return 0;
}

-static void thread_common_ops_tx(struct test_spec *test, struct ifobject *ifobject)
+static int thread_common_ops_tx(struct test_spec *test, struct ifobject *ifobject)
{
- xsk_configure(test, ifobject, test->ifobj_rx->umem, true);
+ int ret = xsk_configure(test, ifobject, test->ifobj_rx->umem, true);
+
+ if (ret)
+ return ret;
ifobject->xsk = &ifobject->xsk_arr[0];
ifobject->xskmap = test->ifobj_rx->xskmap;
memcpy(ifobject->umem, test->ifobj_rx->umem, sizeof(struct xsk_umem_info));
ifobject->umem->base_addr = 0;
+
+ return 0;
}

-static void xsk_populate_fill_ring(struct xsk_umem_info *umem, struct pkt_stream *pkt_stream,
+static int xsk_populate_fill_ring(struct xsk_umem_info *umem, struct pkt_stream *pkt_stream,
bool fill_up)
{
u32 rx_frame_size = umem->frame_size - XDP_PACKET_HEADROOM;
@@ -1491,7 +1505,7 @@ static void xsk_populate_fill_ring(struct xsk_umem_info *umem, struct pkt_stream

ret = xsk_ring_prod__reserve(&umem->fq, buffers_to_fill, &idx);
if (ret != buffers_to_fill)
- exit_with_error(ENOSPC);
+ return -ENOSPC;

while (filled < buffers_to_fill) {
struct pkt *pkt = pkt_stream_get_next_rx_pkt(pkt_stream, &nb_pkts);
@@ -1519,9 +1533,11 @@ static void xsk_populate_fill_ring(struct xsk_umem_info *umem, struct pkt_stream

pkt_stream_reset(pkt_stream);
umem_reset_alloc(umem);
+
+ return 0;
}

-static void thread_common_ops(struct test_spec *test, struct ifobject *ifobject)
+static int thread_common_ops(struct test_spec *test, struct ifobject *ifobject)
{
LIBBPF_OPTS(bpf_xdp_query_opts, opts);
int mmap_flags;
@@ -1541,27 +1557,34 @@ static void thread_common_ops(struct test_spec *test, struct ifobject *ifobject)

bufs = mmap(NULL, umem_sz, PROT_READ | PROT_WRITE, mmap_flags, -1, 0);
if (bufs == MAP_FAILED)
- exit_with_error(errno);
+ return -errno;

ret = xsk_configure_umem(ifobject, ifobject->umem, bufs, umem_sz);
if (ret)
- exit_with_error(-ret);
+ return ret;

- xsk_configure(test, ifobject, ifobject->umem, false);
+ ret = xsk_configure(test, ifobject, ifobject->umem, false);
+ if (ret)
+ return ret;

ifobject->xsk = &ifobject->xsk_arr[0];

if (!ifobject->rx_on)
- return;
+ return 0;

- xsk_populate_fill_ring(ifobject->umem, ifobject->xsk->pkt_stream, ifobject->use_fill_ring);
+ ret = xsk_populate_fill_ring(ifobject->umem, ifobject->xsk->pkt_stream,
+ ifobject->use_fill_ring);
+ if (ret)
+ return ret;

for (i = 0; i < test->nb_sockets; i++) {
ifobject->xsk = &ifobject->xsk_arr[i];
ret = xsk_update_xskmap(ifobject->xskmap, ifobject->xsk->xsk, i);
if (ret)
- exit_with_error(errno);
+ return ret;
}
+
+ return 0;
}

void *worker_testapp_validate_tx(void *arg)
@@ -1571,10 +1594,17 @@ void *worker_testapp_validate_tx(void *arg)
int err;

if (test->current_step == 1) {
- if (!ifobject->shared_umem)
- thread_common_ops(test, ifobject);
- else
- thread_common_ops_tx(test, ifobject);
+ if (!ifobject->shared_umem) {
+ if (thread_common_ops(test, ifobject)) {
+ report_failure(test);
+ pthread_exit(NULL);
+ }
+ } else {
+ if (thread_common_ops_tx(test, ifobject)) {
+ report_failure(test);
+ pthread_exit(NULL);
+ }
+ }
}

err = send_pkts(test, ifobject);
@@ -1594,29 +1624,41 @@ void *worker_testapp_validate_rx(void *arg)
int err;

if (test->current_step == 1) {
- thread_common_ops(test, ifobject);
+ err = thread_common_ops(test, ifobject);
} else {
xsk_clear_xskmap(ifobject->xskmap);
err = xsk_update_xskmap(ifobject->xskmap, ifobject->xsk->xsk, 0);
- if (err) {
+ if (err)
ksft_print_msg("Error: Failed to update xskmap, error %s\n",
strerror(-err));
- exit_with_error(-err);
- }
}

pthread_barrier_wait(&barr);

+ /* We leave only now in case of error to avoid getting stuck in the barrier */
+ if (err) {
+ report_failure(test);
+ pthread_exit(NULL);
+ }
+
err = receive_pkts(test);

if (!err && ifobject->validation_func)
err = ifobject->validation_func(ifobject);

if (err) {
- if (test->adjust_tail && !is_adjust_tail_supported(ifobject->xdp_progs))
- test->adjust_tail_support = false;
- else
+ if (!test->adjust_tail) {
report_failure(test);
+ } else {
+ bool supported;
+
+ if (is_adjust_tail_supported(ifobject->xdp_progs, &supported))
+ report_failure(test);
+ if (!supported)
+ test->adjust_tail_support = false;
+ else
+ report_failure(test);
+ }
}

pthread_exit(NULL);

--
2.50.1