selftests/bpf: Improve percpu_alloc test robustness

Make these non-serial tests filter BPF programs by intended PID of
a test runner process. This makes it isolated from other parallel tests
that might interfere accidentally.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20231011223728.3188086-2-andrii@kernel.org

selftests/bpf: Add some negative tests

Add a few negative tests for common mistakes with using percpu kptr
including:
- store to percpu kptr.
- type mistach in bpf_kptr_xchg arguments.
- sleepable prog with untrusted arg for bpf_this_cpu_ptr().
- bpf_percpu_obj_new && bpf_obj_drop, and bpf_obj_new && bpf_percpu_obj_drop
- struct with ptr for bpf_percpu_obj_new
- struct with special field (e.g., bpf_spin_lock) for bpf_percpu_obj_new

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230827152832.2002421-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add tests for cgrp_local_storage with local percpu kptr

Add a non-sleepable cgrp_local_storage test with percpu kptr. The
test does allocation of percpu data, assigning values to percpu
data and retrieval of percpu data. The de-allocation of percpu
data is done when the map is freed.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230827152827.2001784-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add tests for array map with local percpu kptr

Add non-sleepable and sleepable tests with percpu kptr. For
non-sleepable test, four programs are executed in the order of:
1. allocate percpu data.
2. assign values to percpu data.
3. retrieve percpu data.
4. de-allocate percpu data.

The sleepable prog tried to exercise all above 4 steps in a
single prog. Also for sleepable prog, rcu_read_lock is needed
to protect direct percpu ptr access (from map value) and
following bpf_this_cpu_ptr() and bpf_per_cpu_ptr() helpers.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230827152811.2000125-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>