[PATCH bpf-next v2 2/2] selftests/bpf: add tests for attaching invalid fd
From: Kohei Enju <hidden>
Date: 2025-12-08 13:16:10
Also in:
bpf, linux-kselftest
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest, xdp (express data path) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Linus Torvalds, David S. Miller, Jakub Kicinski, Jesper Dangaard Brouer, John Fastabend
Add test cases for situations where adding the following types of file descriptors to a cpumap entry should fail: - Non-BPF file descriptor (expect -EINVAL) - Nonexistent file descriptor (expect -EBADF) Also tighten the assertion for the expected error when adding a non-BPF_XDP_CPUMAP program to a cpumap entry. Signed-off-by: Kohei Enju <redacted> --- .../bpf/prog_tests/xdp_cpumap_attach.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
index df27535995af..ad56e4370ce3 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c@@ -18,7 +18,7 @@ static void test_xdp_with_cpumap_helpers(void) struct bpf_cpumap_val val = { .qsize = 192, }; - int err, prog_fd, prog_redir_fd, map_fd; + int err, prog_fd, prog_redir_fd, map_fd, bad_fd; struct nstoken *nstoken = NULL; __u32 idx = 0;
@@ -79,7 +79,22 @@ static void test_xdp_with_cpumap_helpers(void) val.qsize = 192; val.bpf_prog.fd = bpf_program__fd(skel->progs.xdp_dummy_prog); err = bpf_map_update_elem(map_fd, &idx, &val, 0); - ASSERT_NEQ(err, 0, "Add non-BPF_XDP_CPUMAP program to cpumap entry"); + ASSERT_EQ(err, -EINVAL, "Add non-BPF_XDP_CPUMAP program to cpumap entry"); + + /* Try to attach non-BPF file descriptor */ + bad_fd = open("/dev/null", O_RDONLY); + ASSERT_GE(bad_fd, 0, "Open /dev/null for non-BPF fd"); + + val.bpf_prog.fd = bad_fd; + err = bpf_map_update_elem(map_fd, &idx, &val, 0); + ASSERT_EQ(err, -EINVAL, "Add non-BPF fd to cpumap entry"); + + /* Try to attach nonexistent file descriptor */ + err = close(bad_fd); + ASSERT_EQ(err, 0, "Close non-BPF fd for nonexistent fd"); + + err = bpf_map_update_elem(map_fd, &idx, &val, 0); + ASSERT_EQ(err, -EBADF, "Add nonexistent fd to cpumap entry"); /* Try to attach BPF_XDP program with frags to cpumap when we have * already loaded a BPF_XDP program on the map
--
2.51.0