selftests/bpf: Use read_perf_max_sample_freq() in perf_event_stackmap

Currently, perf_event sample period in perf_event_stackmap is set too low
that the test fails randomly. Fix this by using the max sample frequency,
from read_perf_max_sample_freq().

Move read_perf_max_sample_freq() to testing_helpers.c. Replace the CHECK()
with if-printf, as CHECK is not available in testing_helpers.c.

Fixes: 1da4864c2b20 ("selftests/bpf: Add callchain_stackid")
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230412210423.900851-2-song@kernel.org

selftests/bpf: Replace extract_build_id with read_build_id

Replacing extract_build_id with read_build_id that parses out
build id directly from elf without using readelf tool.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230331093157.1749137-4-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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: use preferred setter/getter APIs instead of deprecated ones

Switch to using preferred setters and getters instead of deprecated ones.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Turn on libbpf 1.0 mode and fix all IS_ERR checks

Turn ony libbpf 1.0 mode. Fix all the explicit IS_ERR checks that now will be
broken because libbpf returns NULL on error (and sets errno). Fix
ASSERT_OK_PTR and ASSERT_ERR_PTR to work for both old mode and new modes and
use them throughout selftests. This is trivial to do by using
libbpf_get_error() API that all libbpf users are supposed to use, instead of
IS_ERR checks.

A bunch of checks also did explicit -1 comparison for various fd-returning
APIs. Such checks are replaced with >= 0 or < 0 cases.

There were also few misuses of bpf_object__find_map_by_name() in test_maps.
Those are fixed in this patch as well.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210525035935.1461796-3-andrii@kernel.org

bpf: Fix compilation warning of selftests

Clang compiler version: 12.0.0
The following warning appears during the selftests/bpf compilation:

prog_tests/send_signal.c:51:3: warning: ignoring return value of ‘write’,
declared with attribute warn_unused_result [-Wunused-result]
51 | write(pipe_c2p[1], buf, 1);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
prog_tests/send_signal.c:54:3: warning: ignoring return value of ‘read’,
declared with attribute warn_unused_result [-Wunused-result]
54 | read(pipe_p2c[0], buf, 1);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
......

prog_tests/stacktrace_build_id_nmi.c:13:2: warning: ignoring return value
of ‘fscanf’,declared with attribute warn_unused_result [-Wunused-resul]
13 | fscanf(f, "%llu", &sample_freq);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

test_tcpnotify_user.c:133:2: warning:ignoring return value of ‘system’,
declared with attribute warn_unused_result [-Wunused-result]
133 | system(test_script);
| ^~~~~~~~~~~~~~~~~~~
test_tcpnotify_user.c:138:2: warning:ignoring return value of ‘system’,
declared with attribute warn_unused_result [-Wunused-result]
138 | system(test_script);
| ^~~~~~~~~~~~~~~~~~~
test_tcpnotify_user.c:143:2: warning:ignoring return value of ‘system’,
declared with attribute warn_unused_result [-Wunused-result]
143 | system(test_script);
| ^~~~~~~~~~~~~~~~~~~

Add code that fix compilation warning about ignoring return value and
handles any errors; Check return value of library`s API make the code
more secure.

Signed-off-by: Jianlin Lv <Jianlin.Lv@arm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200806104224.95306-1-Jianlin.Lv@arm.com

selftests/bpf: Skip perf hw events test if the setup disabled it

The same with commit 4e59afbbed96 ("selftests/bpf: skip nmi test when perf
hw events are disabled"), it would make more sense to skip the
test_stacktrace_build_id_nmi test if the setup (e.g. virtual machines) has
disabled hardware perf events.

Fixes: 13790d1cc72c ("bpf: add selftest for stackmap with build_id in NMI context")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200117100656.10359-1-liuhangbin@gmail.com

bpftool, selftests/bpf: Embed object file inside skeleton

Embed contents of BPF object file used for BPF skeleton generation inside
skeleton itself. This allows to keep BPF object file and its skeleton in sync
at all times, and simpifies skeleton instantiation.

Also switch existing selftests to not require BPF_EMBED_OBJ anymore.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191218052552.2915188-2-andriin@fb.com

selftests/bpf: Convert few more selftest to skeletons

Convert few more selftests to use generated BPF skeletons as a demonstration
on how to use it.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-16-andriin@fb.com

selftests/bpf: test_progs: remove asserts from subtests

Otherwise they can bring the whole process down.

Cc: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

selftests/bpf: test_progs: test__printf -> printf

Now that test__printf is a simple wraper around printf, let's drop it
(and test__vprintf as well).

Cc: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: abstract away test log output

This patch changes how test output is printed out. By default, if test
had no errors, the only output will be a single line with test number,
name, and verdict at the end, e.g.:

#31 xdp:OK

If test had any errors, all log output captured during test execution
will be output after test completes.

It's possible to force output of log with `-v` (`--verbose`) option, in
which case output won't be buffered and will be output immediately.

To support this, individual tests are required to use helper methods for
logging: `test__printf()` and `test__vprintf()`.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: switch test to new attach_perf_event API

Use new bpf_program__attach_perf_event() in test previously relying on
direct ioctl manipulations.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

selftests: bpf: don't depend on hardcoded perf sample_freq

When running stacktrace_build_id_nmi, try to query
kernel.perf_event_max_sample_rate sysctl and use it as a sample_freq.
If there was an error reading sysctl, fallback to 5000.

kernel.perf_event_max_sample_rate sysctl can drift and/or can be
adjusted by the perf tool, so assuming a fixed number might be
problematic on a long running machine.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests: bpf: break up test_progs - stackmap

Move stackmap prog tests into separate files.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>