selftests/bpf: Add kprobe_multi check to module attach test

Adding test that makes sure the kernel module won't be removed
if there's kprobe multi link defined on top of it.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20221025134148.3300700-8-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Use target-less SEC() definitions in various tests

Add new or modify existing SEC() definitions to be target-less and
validate that libbpf handles such program definitions correctly.

For kprobe/kretprobe we also add explicit test that generic
bpf_program__attach() works in cases when kprobe definition contains
proper target. It wasn't previously tested as selftests code always
explicitly specified the target regardless.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220428185349.3799599-4-andrii@kernel.org

selftest/bpf: Add a test that reads various addresses.

Add a function to bpf_testmod that returns invalid kernel and user addresses.
Then attach an fexit program to that function that tries to read
memory through these addresses.

This logic checks that bpf_probe_read_kernel and BPF_PROBE_MEM logic is sane.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

bpf/selftests: Add test for writable bare tracepoint

Add a writable bare tracepoint in bpf_testmod module, and
trigger its calling when reading /sys/kernel/bpf_testmod
with a specific buffer length. The reading will return
the value in writable context if the early return flag
is enabled in writable context.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211004094857.30868-4-hotforest@gmail.com

selftests: bpf: Add a new test for bare tracepoints

Reuse module_attach infrastructure to add a new bare tracepoint to check
we can attach to it as a raw tracepoint.

Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210119122237.2426878-3-qais.yousef@arm.com

selftests/bpf: Add set_attach_target() API selftest for module target

Add test for bpf_program__set_attach_target() API, validating it can find
kernel module fentry target.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20201211215825.3646154-3-andrii@kernel.org

selftests/bpf: Add fentry/fexit/fmod_ret selftest for kernel module

Add new selftest checking attachment of fentry/fexit/fmod_ret (and raw
tracepoint ones for completeness) BPF programs to kernel module function.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-15-andrii@kernel.org