[PATCH bpf-next v2 3/3] selftests/bpf: add wrong type test to cgroup dev

["Alexis Lothoré (eBPF Foundation)" <alexis.lothore@bootlin.com>]

Current cgroup_dev test mostly tests that device operation is accepted or
refused base on passed major/minor (and so, any operation performed during
test involves only char device)

Add a small subtest ensuring that the device type passed to bpf program
allows it to take decisions as well.

Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com>
---
Changes in v2:
- change test name ("null" block device does not make sense)
- use updated subtest API for this new subtest
---
 tools/testing/selftests/bpf/prog_tests/cgroup_dev.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_dev.c b/tools/testing/selftests/bpf/prog_tests/cgroup_dev.c
index af0b70086c21..a840973c87b1 100644
--- a/tools/testing/selftests/bpf/prog_tests/cgroup_dev.c
+++ b/tools/testing/selftests/bpf/prog_tests/cgroup_dev.c
@@ -91,6 +91,9 @@ void test_cgroup_dev(void)
 	if (test__start_subtest("allow-mknod"))
 		test_mknod("/dev/test_dev_cgroup_null", S_IFCHR, 1, 3, 0);
 
+	if (test__start_subtest("deny-mknod-wrong-type"))
+		test_mknod("/dev/test_dev_cgroup_block", S_IFBLK, 1, 3, -EPERM);
+
 	if (test__start_subtest("allow-read"))
 		test_read("/dev/urandom", buf, TEST_BUFFER_SIZE, TEST_BUFFER_SIZE);
 

-- 
2.45.2