selftests/bpf: Add ref_ctr_offset selftests
Extend attach_probe selftests to specify ref_ctr_offset for uprobe/uretprobe
and validate that its value is incremented from zero.
Turns out that once uprobe is attached with ref_ctr_offset, uretprobe for the
same location/function *has* to use ref_ctr_offset as well, otherwise
perf_event_open() fails with -EINVAL. So this test uses ref_ctr_offset for
both uprobe and uretprobe, even though for the purpose of test uprobe would be
enough.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-17-andrii@kernel.org
diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h
index 3d9435b..d907b44 100644
--- a/tools/testing/selftests/bpf/trace_helpers.h
+++ b/tools/testing/selftests/bpf/trace_helpers.h
@@ -20,5 +20,6 @@ void read_trace_pipe(void);
ssize_t get_uprobe_offset(const void *addr, ssize_t base);
ssize_t get_base_addr(void);
+ssize_t get_rel_offset(uintptr_t addr);
#endif
