fn init_perf_event_attr()

in reverie-ptrace/src/validation.rs [75:105]

• 25 lines of code
• 3 McCabe index (conditional complexity)

fn init_perf_event_attr(
    perf_attr_type: u32,
    config: u64,
    precise_ip: bool,
) -> perf::perf_event_attr {
    let mut result = perf::perf_event_attr {
        type_: perf_attr_type,
        config,
        ..Default::default()
    };
    result.size = mem::size_of_val(&result) as u32;
    result.set_exclude_guest(1);
    result.set_exclude_kernel(1);

    if precise_ip
        && CpuId::new()
            .get_feature_info()
            .map_or(false, |info| info.has_ds())
    {
        result.set_precise_ip(1);

        // This prevents EINVAL when creating a counter with precise_ip enabled
        result.__bindgen_anon_1.sample_period = PerfCounter::DISABLE_SAMPLE_PERIOD;
    } else {
        // This is the value used for the bug checks which are not originally designed to
        // work with precise_ip
        result.__bindgen_anon_1.sample_period = 0;
    }

    result
}