selftests/bpf: add anonymous user struct as global subprog arg test

Add tests validating that kernel handles pointer to anonymous struct
argument as PTR_TO_MEM case, not as PTR_TO_CTX case.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240212233221.2575350-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: add tests confirming type logic in kernel for __arg_ctx

Add a bunch of global subprogs across variety of program types to
validate expected kernel type enforcement logic for __arg_ctx arguments.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240118033143.3384355-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: add global subprog annotation tests

Add test cases to validate semantics of global subprog argument
annotations:
- non-null pointers;
- context argument;
- const dynptr passing;
- packet pointers (data, metadata, end).

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231215011334.2307144-10-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: validate eliminated global subprog is not freplaceable

Add selftest that establishes dead code-eliminated valid global subprog
(global_dead) and makes sure that it's not possible to freplace it, as
it's effectively not there. This test will fail with unexpected success
before 2afae08c9dcb ("bpf: Validate global subprogs lazily").

v2->v3:
- add missing err assignment (Alan);
- undo unnecessary signature changes in verifier_global_subprogs.c (Eduard);
v1->v2:
- don't rely on assembly output in verifier log, which changes between
compiler versions (CI).

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20231211174131.2324306-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add lazy global subprog validation tests

Add a few test that validate BPF verifier's lazy approach to validating
global subprogs.

We check that global subprogs that are called transitively through
another global subprog is validated.

We also check that invalid global subprog is not validated, if it's not
called from the main program.

And we also check that main program is always validated first, before
any of the subprogs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231124035937.403208-4-andrii@kernel.org