Alexei Starovoitov wrote:

From: Alexei Starovoitov <ast@kernel.org>

Add placeholders for bpf_sys_bpf() helper and new program type.

v1->v2:
- check that expected_attach_type is zero
- allow more helper functions to be used in this program type, since they will
  only execute from user context via bpf_prog_test_run.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---

Acked-by: John Fastabend <john.fastabend@gmail.com>

+int bpf_prog_test_run_syscall(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;
+	void *ctx = NULL;
+	u32 retval;
+	int err = 0;
+
+	/* doesn't support data_in/out, ctx_out, duration, or repeat or flags */
+	if (kattr->test.data_in || kattr->test.data_out ||
+	    kattr->test.ctx_out || kattr->test.duration ||
+	    kattr->test.repeat || kattr->test.flags)
+		return -EINVAL;
+
+	if (ctx_size_in < prog->aux->max_ctx_offset ||
+	    ctx_size_in > U16_MAX)
+		return -EINVAL;
+
+	if (ctx_size_in) {
+		ctx = kzalloc(ctx_size_in, GFP_USER);
+		if (!ctx)
+			return -ENOMEM;
+		if (copy_from_user(ctx, ctx_in, ctx_size_in)) {
+			err = -EFAULT;
+			goto out;
+		}
+	}
+	retval = bpf_prog_run_pin_on_cpu(prog, ctx);
+
+	if (copy_to_user(&uattr->test.retval, &retval, sizeof(u32)))
+		err = -EFAULT;
+	if (ctx_size_in)
+		if (copy_to_user(ctx_in, ctx, ctx_size_in)) {
+			err = -EFAULT;
+			goto out;
+		}

stupid nit, the last goto there is not needed.

+out:
+	kfree(ctx);
+	return err;
+}