From d7e5768763ff39201761e7c4dfb07cd18c724344 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sun, 5 Sep 2021 17:50:34 +0200
Subject: [PATCH] Kernel: Add copy_typed_from_userspace<T>(Userspace<T const*>)

This allows easy retrieval of typed POD values from userspace with
implicit error propagation.
---
 Kernel/StdLib.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Kernel/StdLib.h b/Kernel/StdLib.h
index 37eb932394..0b9c3f9158 100644
--- a/Kernel/StdLib.h
+++ b/Kernel/StdLib.h
@@ -167,3 +167,11 @@ template<typename T>
         return EOVERFLOW;
     return copy_to_user(dest.unsafe_userspace_ptr(), src, size.value());
 }
+
+template<typename T>
+inline KResultOr<T> copy_typed_from_user(Userspace<T const*> user_data)
+{
+    T data {};
+    TRY(copy_from_user(&data, user_data));
+    return data;
+}