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 <tjmercier@google.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Song Liu <song@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");
+ } while (bpf_map_get_next_key(map_fd, key, key));
+}
+
void test_dmabuf_iter(void)
{
struct dmabuf_iter *skel = NULL;
+ int map_fd;
+ const bool f = false;
skel = dmabuf_iter__open_and_load();
if (!ASSERT_OK_PTR(skel, "dmabuf_iter__open_and_load"))
return;
+ map_fd = bpf_map__fd(skel->maps.testbuf_hash);
+ if (!ASSERT_OK_FD(map_fd, "map_fd"))
+ goto destroy_skel;
+
+ if (!ASSERT_OK(bpf_map_update_elem(map_fd, udmabuf_test_buffer_name, &f, BPF_ANY),
+ "insert udmabuf"))
+ goto destroy_skel;
+ if (!ASSERT_OK(bpf_map_update_elem(map_fd, sysheap_test_buffer_name, &f, BPF_ANY),
+ "insert sysheap buffer"))
+ goto destroy_skel;
+
if (!ASSERT_OK(create_test_buffers(), "create_test_buffers"))
goto destroy;
@@ -237,8 +275,11 @@ void test_dmabuf_iter(void)
subtest_dmabuf_iter_check_no_infinite_reads(skel);
if (test__start_subtest("default_iter"))
subtest_dmabuf_iter_check_default_iter(skel);
+ if (test__start_subtest("open_coded"))
+ subtest_dmabuf_iter_check_open_coded(skel, map_fd);
destroy:
destroy_test_buffers();
+destroy_skel:
dmabuf_iter__destroy(skel);
}
diff --git a/tools/testing/selftests/bpf/progs/dmabuf_iter.c b/tools/testing/selftests/bpf/progs/dmabuf_iter.c
index 2a1b5397196d..bd4ebfc9161c 100644
--- a/tools/testing/selftests/bpf/progs/dmabuf_iter.c
+++ b/tools/testing/selftests/bpf/progs/dmabuf_iter.c
@@ -9,6 +9,13 @@
char _license[] SEC("license") = "GPL";
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __uint(key_size, DMA_BUF_NAME_LEN);
+ __type(value, bool);
+ __uint(max_entries, 5);
+} testbuf_hash SEC(".maps");
+
/*
* Fields output by this iterator are delimited by newlines. Convert any
* newlines in user-provided printed strings to spaces.
@@ -51,3 +58,34 @@ int dmabuf_collector(struct bpf_iter__dmabuf *ctx)
BPF_SEQ_PRINTF(seq, "%lu\n%llu\n%s\n%s\n", inode, size, name, exporter);
return 0;
}
+
+SEC("syscall")
+int iter_dmabuf_for_each(const void *ctx)
+{
+ struct dma_buf *d;
+
+ bpf_for_each(dmabuf, d) {
+ char name[DMA_BUF_NAME_LEN];
+ const char *pname;
+ bool *found;
+
+ if (bpf_core_read(&pname, sizeof(pname), &d->name))
+ return 1;
+
+ /* Buffers are not required to be named */
+ if (!pname)
+ continue;
+
+ if (bpf_probe_read_kernel(name, sizeof(name), pname))
+ return 1;
+
+ found = bpf_map_lookup_elem(&testbuf_hash, name);
+ if (found) {
+ bool t = true;
+
+ bpf_map_update_elem(&testbuf_hash, name, &t, BPF_EXIST);
+ }
+ }
+
+ return 0;
+}
--
2.49.0.1045.g170613ef41-googOn Tue, May 13, 2025 at 9:36 AM T.J. Mercier <tjmercier@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 <tjmercier@google.com>
> Acked-by: Christian König <christian.koenig@amd.com>
> Acked-by: Song Liu <song@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));
> +}
[...]
On Wed, May 14, 2025 at 2:00 PM Song Liu <song@kernel.org> wrote:
>
> On Tue, May 13, 2025 at 9:36 AM T.J. Mercier <tjmercier@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 <tjmercier@google.com>
> > Acked-by: Christian König <christian.koenig@amd.com>
> > Acked-by: Song Liu <song@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
Thanks, yeah I have been trying to run this locally today but still
working on setting up an environment for it. Daniel Xu thoughtfully
suggested I use a github PR to trigger CI, but I tried that last week
without success: https://github.com/kernel-patches/bpf/pull/8910
I'm not sure if this is the cause (doesn't show up on the runs that
pass) but I have no idea why that would be intermittently failing:
libbpf: Error in bpf_create_map_xattr(testbuf_hash): -EINVAL. Retrying
without BTF.
> > + } while (bpf_map_get_next_key(map_fd, key, key));
> > +}
>
> [...]
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