selftests/xsk: Add support check for bpf_xdp_adjust_tail() helper in …

…xskxceiver Add is_adjust_tail_supported function to check if the bpf_xdp_adjust_tail() helper is supported when 'adjust_tail' is set in the test. Look up a specific key in the bss section of the XDP program. If the key is not found or its value is -EOPNOTSUPP, return false, indicating that the helper is not supported. Signed-off-by: Tushar Vyavahare <[email protected]>
kernel-patches · Feb 21, 2025 · 6dac82b · 6dac82b
1 parent 90107a8
commit 6dac82b
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Showing 2 changed files with 36 additions and 2 deletions.
diff --git a/tools/testing/selftests/bpf/xskxceiver.c b/tools/testing/selftests/bpf/xskxceiver.c
@@ -524,6 +524,8 @@ static void __test_spec_init(struct test_spec *test, struct ifobject *ifobj_tx,
 	test->nb_sockets = 1;
 	test->fail = false;
 	test->set_ring = false;
+	test->adjust_tail = false;
+	test->adjust_tail_support = false;
 	test->mtu = MAX_ETH_PKT_SIZE;
 	test->xdp_prog_rx = ifobj_rx->xdp_progs->progs.xsk_def_prog;
 	test->xskmap_rx = ifobj_rx->xdp_progs->maps.xsk;
@@ -992,6 +994,31 @@ 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)
+{
+	struct bpf_map *data_map;
+	int value = 0;
+	int key = 0;
+	int ret;
+
+	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);
+	}
+
+	ret = bpf_map_lookup_elem(bpf_map__fd(data_map), &key, &value);
+	if (ret) {
+		ksft_print_msg("Error: bpf_map_lookup_elem failed with error %d\n", ret);
+		return false;
+	}
+
+	/* Set the 'count' 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 value != -EOPNOTSUPP;
+}
+
 static bool is_frag_valid(struct xsk_umem_info *umem, u64 addr, u32 len, u32 expected_pkt_nb,
 			  u32 bytes_processed)
 {
@@ -1768,8 +1795,13 @@ static void *worker_testapp_validate_rx(void *arg)
 
 	if (!err && ifobject->validation_func)
 		err = ifobject->validation_func(ifobject);
-	if (err)
-		report_failure(test);
+
+	if (err) {
+		if (test->adjust_tail && !is_adjust_tail_supported(ifobject->xdp_progs))
+			test->adjust_tail_support = false;
+		else
+			report_failure(test);
+	}
 
 	pthread_exit(NULL);
 }

diff --git a/tools/testing/selftests/bpf/xskxceiver.h b/tools/testing/selftests/bpf/xskxceiver.h
@@ -173,6 +173,8 @@ struct test_spec {
 	u16 nb_sockets;
 	bool fail;
 	bool set_ring;
+	bool adjust_tail;
+	bool adjust_tail_support;
 	enum test_mode mode;
 	char name[MAX_TEST_NAME_SIZE];
 };