selftests/bpf: Query BPF_MAX_TRAMP_LINKS using BTF

Do not hard-code the value, since for s390x it will be smaller than
for x86.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230128000650.1516334-4-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Fix test_run logic in fexit_stress.c

In the commit da00d2f117a0 ("bpf: Add test ops for BPF_PROG_TYPE_TRACING"),
the bpf_fentry_test1 function was moved into bpf_prog_test_run_tracing(),
which is the test_run function of the tracing BPF programs.

Thus calling 'bpf_prog_test_run_opts(filter_fd, &topts)' will not trigger
bpf_fentry_test1 function as filter_fd is a sk_filter BPF program.

Fix it by replacing filter_fd with fexit_fd in the bpf_prog_test_run_opts()
function.

Fixes: da00d2f117a0 ("bpf: Add test ops for BPF_PROG_TYPE_TRACING")
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220521151329.648013-1-ytcoode@gmail.com

selftests/bpf: make fexit_stress test run in serial mode

fexit_stress is attaching maximum allowed amount of fexit programs to
bpf_fentry_test1 kernel function, which is used by a bunch of other
parallel tests, thus pretty frequently interfering with their execution.

Given the test assumes nothing else is attaching to bpf_fentry_test1,
mark it serial.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220511232012.609370-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Switch fexit_stress to bpf_link_create() API

Use bpf_link_create() API in fexit_stress test to attach FEXIT programs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Kui-Feng Lee <kuifeng@fb.com>
Link: https://lore.kernel.org/bpf/20220421033945.3602803-4-andrii@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: Convert legacy prog load APIs to bpf_prog_load()

Convert all the uses of legacy low-level BPF program loading APIs
(mostly bpf_load_program_xattr(), but also some bpf_verify_program()) to
bpf_prog_load() uses.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-10-andrii@kernel.org

bpf: Add per-program recursion prevention mechanism

Since both sleepable and non-sleepable programs execute under migrate_disable
add recursion prevention mechanism to both types of programs when they're
executed via bpf trampoline.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210210033634.62081-5-alexei.starovoitov@gmail.com

selftests/bpf: Add stress test for maximum number of progs

Add stress test for maximum number of attached BPF programs per BPF trampoline.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-13-ast@kernel.org