Make sure that bpf_prog_test_run_xattr returns the correct length
and that the kernel respects the output size hint. Also check
that errno indicates ENOSPC if there is a short output buffer given.
Signed-off-by: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
---
tools/testing/selftests/bpf/test_progs.c | 49 ++++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index c1e688f61061..f9f5b1dbcc83 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -124,6 +124,54 @@ static void test_pkt_access(void)
bpf_object__close(obj);
}
+static void test_prog_run_xattr(void)
+{
+ const char *file = "./test_pkt_access.o";
+ __u32 duration, retval, size_out;
+ struct bpf_object *obj;
+ char buf[10];
+ int err;
+ struct bpf_prog_test_run_attr tattr = {
+ .repeat = 1,
+ .data = &pkt_v4,
+ .size = sizeof(pkt_v4),
+ .data_out = buf,
+ .size_out = 5,
+ };
+
+ err = bpf_prog_load(file, BPF_PROG_TYPE_SCHED_CLS, &obj,
+ &tattr.prog_fd);
+ if (CHECK(err, "load", "err %d errno %d\n", err, errno))
+ return;
+
+ memset(buf, 0, sizeof(buf));
+
+ err = bpf_prog_test_run_xattr(&tattr, &size_out, &retval, &duration);
+ CHECK(err != -1 || errno != ENOSPC || retval, "run",
+ "err %d errno %d retval %d\n", err, errno, retval);
+
+ CHECK(size_out != sizeof(pkt_v4), "output_size",
+ "incorrect output size, want %lu have %u\n",
+ sizeof(pkt_v4), size_out);
+
+ CHECK(buf[5] != 0, "overflow",
+ "BPF_PROG_TEST_RUN ignored size hint\n");
+
+ tattr.data_out = NULL;
+ tattr.size_out = 0;
+ errno = 0;
+
+ err = bpf_prog_test_run_xattr(&tattr, NULL, &retval, &duration);
+ CHECK(err || errno || retval, "run_no_output",
+ "err %d errno %d retval %d\n", err, errno, retval);
+
+ tattr.size_out = 1;
+ err = bpf_prog_test_run_xattr(&tattr, NULL, NULL, &duration);
+ CHECK(err != -EINVAL, "run_wrong_size_out", "err %d\n", err);
+
+ bpf_object__close(obj);
+}
+
static void test_xdp(void)
{
struct vip key4 = {.protocol = 6, .family = AF_INET};
@@ -1837,6 +1885,7 @@ int main(void)
jit_enabled = is_jit_enabled();
test_pkt_access();
+ test_prog_run_xattr();
test_xdp();
test_xdp_adjust_tail();
test_l4lb_all();
--
2.17.1
