[PATCH v3 net 6/8] selftests: bpf: have a separate variable for drop test
From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Date: 2026-03-23 19:25:27
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest, xdp (express data path), xdp sockets (af_xdp) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Shuah Khan, Linus Torvalds, David S. Miller, Jakub Kicinski, Jesper Dangaard Brouer, John Fastabend, Magnus Karlsson, Maciej Fijalkowski
Currently two different XDP programs share a static variable for different purposes (picking where to redirect on shared umem test & whether to drop a packet). This can be a problem when running full test suite - idx can be written by shared umem test and this value can cause a false behavior within XDP drop half test. Introduce a dedicated variable for drop half test so that these two don't step on each other toes. There is no real need for using __sync_fetch_and_add here as XSK tests are executed on single CPU. Reviewed-by: Björn Töpel <bjorn@kernel.org> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> --- tools/testing/selftests/bpf/progs/xsk_xdp_progs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c b/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c
index 683306db8594..023d8befd4ca 100644
--- a/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c
+++ b/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c@@ -26,8 +26,10 @@ SEC("xdp.frags") int xsk_def_prog(struct xdp_md *xdp) SEC("xdp.frags") int xsk_xdp_drop(struct xdp_md *xdp) { + static unsigned int drop_idx; + /* Drop every other packet */ - if (idx++ % 2) + if (drop_idx++ % 2) return XDP_DROP; return bpf_redirect_map(&xsk, 0, XDP_DROP);
--
2.43.0