On Mon, Jun 15, 2026 at 10:13 PM Paul Chaignon <[email protected]> wrote: > > On Mon, Jun 15, 2026 at 03:38:56PM +0800, Sun Jian wrote: > > Add a test case for BPF_PROG_TEST_RUN with a non-linear skb and a short > > data_out buffer. > > > > The test verifies that test_run returns -ENOSPC, reports the full packet > > length through data_size_out, and copies the packet prefix into data_out. > > The test uses a 100-byte data_out buffer with a 64-byte linear head, so the > > expected output spans both the skb head and the first fragment. > > > > Signed-off-by: Sun Jian <[email protected]> > > --- > > .../selftests/bpf/prog_tests/skb_load_bytes.c | 35 +++++++++++++++++++ > > 1 file changed, 35 insertions(+) > > > > diff --git a/tools/testing/selftests/bpf/prog_tests/skb_load_bytes.c > > b/tools/testing/selftests/bpf/prog_tests/skb_load_bytes.c > > index d7f83c0a40a5..134be0ea8ed7 100644 > > --- a/tools/testing/selftests/bpf/prog_tests/skb_load_bytes.c > > +++ b/tools/testing/selftests/bpf/prog_tests/skb_load_bytes.c > > @@ -3,6 +3,39 @@ > > #include <network_helpers.h> > > #include "skb_load_bytes.skel.h" > > > > +#define NONLINEAR_PKT_LEN 9000 > > +#define NONLINEAR_HEAD_LEN 64 > > +#define SHORT_OUT_LEN 100 > > + > > +static void test_nonlinear_data_out_partial(int prog_fd) > > +{ > > + LIBBPF_OPTS(bpf_test_run_opts, tattr); > > + __u8 pkt[NONLINEAR_PKT_LEN]; > > + __u8 out[SHORT_OUT_LEN]; > > + struct __sk_buff skb = {}; > > + int err, i; > > + > > + for (i = 0; i < sizeof(pkt); i++) > > + pkt[i] = i & 0xff; > > + > > + memset(out, 0xa5, sizeof(out)); > > + > > + skb.data_end = NONLINEAR_HEAD_LEN; > > + > > + tattr.data_in = pkt; > > + tattr.data_size_in = sizeof(pkt); > > + tattr.data_out = out; > > + tattr.data_size_out = sizeof(out); > > + tattr.ctx_in = &skb; > > + tattr.ctx_size_in = sizeof(skb); > > + > > + err = bpf_prog_test_run_opts(prog_fd, &tattr); > > + > > + ASSERT_EQ(err, -ENOSPC, "nonlinear_partial_err"); > > + ASSERT_EQ(tattr.data_size_out, sizeof(pkt), > > "nonlinear_partial_data_size_out"); > > + ASSERT_OK(memcmp(out, pkt, sizeof(out)), > > "nonlinear_partial_data_out"); > > +} > > + > > void test_skb_load_bytes(void) > > { > > struct skb_load_bytes *skel; > > @@ -40,6 +73,8 @@ void test_skb_load_bytes(void) > > if (!ASSERT_EQ(test_result, 0, "offset 10")) > > goto out; > > > > + test_nonlinear_data_out_partial(prog_fd); > > + > > Maybe prog_tests/prog_run_opts.c would be a better place to cover this? > test_skb_load_bytes() is meant to cover the bpf_skb_load_bytes helper. > > > out: > > skb_load_bytes__destroy(skel); > > } > > -- > > 2.43.0 > >
Hi Paul, Thanks, agreed. The test is really about BPF_PROG_TEST_RUN copy-out semantics, not the bpf_skb_load_bytes() helper. I'll move it to prog_run_opts.c in v2. Thanks, Sun Jian
