selftests/bpf: Convert some selftests to high-level BPF map APIs

Convert a bunch of selftests to using newly added high-level BPF map
APIs.

This change exposed that map_kptr selftests allocated too big buffer,
which is fixed in this patch as well.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220512220713.2617964-2-andrii@kernel.org

selftests/bpf: Test for writes to map key from BPF helpers

When invoking bpf_for_each_map_elem callback, we are passed a
PTR_TO_MAP_KEY, previously writes to this through helper may be allowed,
but the fix in previous patches is meant to prevent that case. The test
case tries to pass it as writable memory to helper, and fails test if it
succeeds to pass the verifier.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220319080827.73251-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Migrate from bpf_prog_test_run

bpf_prog_test_run is being deprecated in favor of the OPTS-based
bpf_prog_test_run_opts.
We end up unable to use CHECK in most cases, so replace usages with
ASSERT_* calls.

Signed-off-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220202235423.1097270-2-delyank@fb.com

selftests/bpf: Add arraymap test for bpf_for_each_map_elem() helper

A test is added for arraymap and percpu arraymap. The test also
exercises the early return for the helper which does not
traverse all elements.
$ ./test_progs -n 45
#45/1 hash_map:OK
#45/2 array_map:OK
#45 for_each:OK
Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210226204934.3885756-1-yhs@fb.com

selftests/bpf: Add hashmap test for bpf_for_each_map_elem() helper

A test case is added for hashmap and percpu hashmap. The test
also exercises nested bpf_for_each_map_elem() calls like
bpf_prog:
bpf_for_each_map_elem(func1)
func1:
bpf_for_each_map_elem(func2)
func2:

$ ./test_progs -n 45
#45/1 hash_map:OK
#45 for_each:OK
Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210226204933.3885657-1-yhs@fb.com