Song Liu wrote:
> Add .test_run for raw_tracepoint. Also, introduce a new feature that runs
> the target program on a specific CPU. This is achieved by a new flag in
> bpf_attr.test, cpu_plus. For compatibility, cpu_plus == 0 means run the
> program on current cpu, cpu_plus > 0 means run the program on cpu with id
> (cpu_plus - 1). This feature is needed for BPF programs that handle
> perf_event and other percpu resources, as the program can access these
> resource locally.
>
> Signed-off-by: Song Liu <songliubraving@xxxxxx>
> ---
Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>
[...]
> +
> +int bpf_prog_test_run_raw_tp(struct bpf_prog *prog,
> + const union bpf_attr *kattr,
> + union bpf_attr __user *uattr)
> +{
> + void __user *ctx_in = u64_to_user_ptr(kattr->test.ctx_in);
> + __u32 ctx_size_in = kattr->test.ctx_size_in;
> + struct bpf_raw_tp_test_run_info info;
> + int cpu, err = 0;
> +
> + /* doesn't support data_in/out, ctx_out, duration, or repeat */
> + if (kattr->test.data_in || kattr->test.data_out ||
> + kattr->test.ctx_out || kattr->test.duration ||
> + kattr->test.repeat)
> + return -EINVAL;
> +
> + if (ctx_size_in < prog->aux->max_ctx_offset)
> + return -EINVAL;
> +
> + if (ctx_size_in) {
> + info.ctx = kzalloc(ctx_size_in, GFP_USER);
> + if (!info.ctx)
> + return -ENOMEM;
> + if (copy_from_user(info.ctx, ctx_in, ctx_size_in)) {
> + err = -EFAULT;
> + goto out;
> + }
> + } else {
> + info.ctx = NULL;
> + }
> +
> + info.prog = prog;
> + cpu = kattr->test.cpu_plus - 1;
> +
> + if (!kattr->test.cpu_plus || cpu == smp_processor_id()) {
> + __bpf_prog_test_run_raw_tp(&info);
> + } else {
> + /* smp_call_function_single() also checks cpu_online()
> + * after csd_lock(). However, since cpu_plus is from user
> + * space, let's do an extra quick check to filter out
> + * invalid value before smp_call_function_single().
> + */
> + if (!cpu_online(cpu)) {
> + err = -ENXIO;
> + goto out;
> + }
> +
> + err = smp_call_function_single(cpu, __bpf_prog_test_run_raw_tp,
> + &info, 1);
> + if (err)
> + goto out;
> + }
> +
> + if (copy_to_user(&uattr->test.retval, &info.retval, sizeof(u32))) {
> + err = -EFAULT;
> + goto out;
> + }
This goto is not needed. I don't mind it though.
> +
> +out:
> + kfree(info.ctx);
> + return err;
> +}
> +
