selftests/bpf: Add test for key-less BTF hash map

Create a hash and an rhash map with btf_key_type_id == 0 and expect
bpf_map_create() to fail with -EINVAL; a positive control with a real
key type confirms the rejection is about the key-less BTF and not some
unrelated failure.

Such a map used to be accepted and then NULL-deref in btf_type_show()
when dumped through bpffs.

Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://lore.kernel.org/r/20260901104924.346187-5-jiayuan.chen@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

0 files changed, 0 insertions, 0 deletions