Commit c9110e6f authored by Ricardo B. Marlière's avatar Ricardo B. Marlière Committed by Andrii Nakryiko
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selftests/bpf: Fix count write in testapp_xdp_metadata_copy() 



Commit 4b302092 ("selftests/xsk: Add tail adjustment tests and support
check") added a new global to xsk_xdp_progs.c, but left out the access in
the testapp_xdp_metadata_copy() function. Since bpf_map_update_elem() will
write to the whole bss section, it gets truncated. Fix by writing to
skel_rx->bss->count directly.

Fixes: 4b302092 ("selftests/xsk: Add tail adjustment tests and support check")
Signed-off-by: default avatarRicardo B. Marlière <rbm@suse.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250829-selftests-bpf-xsk_regression_fix-v1-1-5f5acdb9fe6b@suse.com
parent 2a912258

tools/testing/selftests/bpf/xskxceiver.c

+1 −13
Original line number Diff line number Diff line
@@ -2276,25 +2276,13 @@ static int testapp_xdp_metadata_copy(struct test_spec *test) 
{

	struct xsk_xdp_progs *skel_rx = test->ifobj_rx->xdp_progs;

	struct xsk_xdp_progs *skel_tx = test->ifobj_tx->xdp_progs;

	struct bpf_map *data_map;

	int count = 0;

	int key = 0;



	test_spec_set_xdp_prog(test, skel_rx->progs.xsk_xdp_populate_metadata,

			       skel_tx->progs.xsk_xdp_populate_metadata,

			       skel_rx->maps.xsk, skel_tx->maps.xsk);

	test->ifobj_rx->use_metadata = true;



	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");

		return TEST_FAILURE;

	}



	if (bpf_map_update_elem(bpf_map__fd(data_map), &key, &count, BPF_ANY)) {

		ksft_print_msg("Error: could not update count element\n");

		return TEST_FAILURE;

	}

	skel_rx->bss->count = 0;



	return testapp_validate_traffic(test);

}