Add a kselftest to cover bpf auto-detachment functionality.
The test creates a cgroup, associates some resources with it,
attaches a couple of bpf programs and deletes the cgroup.
Then it checks that bpf programs are going away in 5 seconds.
Expected output:
$ ./test_cgroup_attach
#override:PASS
#multi:PASS
#autodetach:PASS
test_cgroup_attach:PASS
On a kernel without auto-detaching:
$ ./test_cgroup_attach
#override:PASS
#multi:PASS
#autodetach:FAIL
test_cgroup_attach:FAIL
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>