Adding tests for the rollback code when the tracing_multi link won't get attached, covering 2 reasons: - wrong btf id passed by user, where all previously allocated trampolines will be released - trampoline for requested function is fully attached (has already maximum programs attached) and the link fails, the rollback code needs to release all previously link-ed trampolines and release them We need the bpf_fentry_test* unattached for the tests to pass, so the rollback tests are serial. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20260606123955.345967-30-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>