On Tue, May 13, 2025 at 9:36 AM T.J. Mercier <tjmerc...@google.com> wrote:
>
> Use the same test buffers as the traditional iterator and a new BPF map
> to verify the test buffers can be found with the open coded dmabuf
> iterator.
>
> Signed-off-by: T.J. Mercier <tjmerc...@google.com>
> Acked-by: Christian König <christian.koe...@amd.com>
> Acked-by: Song Liu <s...@kernel.org>
> ---
> .../testing/selftests/bpf/bpf_experimental.h | 5 +++
> .../selftests/bpf/prog_tests/dmabuf_iter.c | 41 +++++++++++++++++++
> .../testing/selftests/bpf/progs/dmabuf_iter.c | 38 +++++++++++++++++
> 3 files changed, 84 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/bpf_experimental.h
> b/tools/testing/selftests/bpf/bpf_experimental.h
> index 6535c8ae3c46..5e512a1d09d1 100644
> --- a/tools/testing/selftests/bpf/bpf_experimental.h
> +++ b/tools/testing/selftests/bpf/bpf_experimental.h
> @@ -591,4 +591,9 @@ extern int bpf_iter_kmem_cache_new(struct
> bpf_iter_kmem_cache *it) __weak __ksym
> extern struct kmem_cache *bpf_iter_kmem_cache_next(struct
> bpf_iter_kmem_cache *it) __weak __ksym;
> extern void bpf_iter_kmem_cache_destroy(struct bpf_iter_kmem_cache *it)
> __weak __ksym;
>
> +struct bpf_iter_dmabuf;
> +extern int bpf_iter_dmabuf_new(struct bpf_iter_dmabuf *it) __weak __ksym;
> +extern struct dma_buf *bpf_iter_dmabuf_next(struct bpf_iter_dmabuf *it)
> __weak __ksym;
> +extern void bpf_iter_dmabuf_destroy(struct bpf_iter_dmabuf *it) __weak
> __ksym;
> +
> #endif
> diff --git a/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c
> b/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c
> index dc740bd0e2bd..6c2b0c3dbcd8 100644
> --- a/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c
> +++ b/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c
> @@ -219,14 +219,52 @@ static void
> subtest_dmabuf_iter_check_default_iter(struct dmabuf_iter *skel)
> close(iter_fd);
> }
>
> +static void subtest_dmabuf_iter_check_open_coded(struct dmabuf_iter *skel,
> int map_fd)
> +{
> + LIBBPF_OPTS(bpf_test_run_opts, topts);
> + char key[DMA_BUF_NAME_LEN];
> + int err, fd;
> + bool found;
> +
> + /* No need to attach it, just run it directly */
> + fd = bpf_program__fd(skel->progs.iter_dmabuf_for_each);
> +
> + err = bpf_prog_test_run_opts(fd, &topts);
> + if (!ASSERT_OK(err, "test_run_opts err"))
> + return;
> + if (!ASSERT_OK(topts.retval, "test_run_opts retval"))
> + return;
> +
> + if (!ASSERT_OK(bpf_map_get_next_key(map_fd, NULL, key), "get next
> key"))
> + return;
> +
> + do {
> + ASSERT_OK(bpf_map_lookup_elem(map_fd, key, &found), "lookup");
> + ASSERT_TRUE(found, "found test buffer");
This check failed once in the CI, on s390:
Error: #89/3 dmabuf_iter/open_coded
9309 subtest_dmabuf_iter_check_open_coded:PASS:test_run_opts err 0 nsec
9310 subtest_dmabuf_iter_check_open_coded:PASS:test_run_opts retval 0 nsec
9311 subtest_dmabuf_iter_check_open_coded:PASS:get next key 0 nsec
9312 subtest_dmabuf_iter_check_open_coded:PASS:lookup 0 nsec
9313 subtest_dmabuf_iter_check_open_coded:FAIL:found test buffer
unexpected found test buffer: got FALSE
But it passed in the rerun. It is probably a bit flakey. Maybe we need some
barrier somewhere.
Here is the failure:
https://github.com/kernel-patches/bpf/actions/runs/15002058808/job/42234864754
To see the log, you need to log in GitHub.
Thanks,
Song
> + } while (bpf_map_get_next_key(map_fd, key, key));
> +}
[...]
