From a27aaceee91c1b3a7b4f9b070054290e8530e1bd Mon Sep 17 00:00:00 2001
From: Raoul Strackx <raoul.strackx@fortanix.com>
Date: Tue, 22 Mar 2022 17:34:44 +0100
Subject: [PATCH] Test `copy_to_userspace` function

---
 .../std/src/sys/sgx/abi/usercalls/alloc.rs    |  2 +-
 library/std/src/sys/sgx/abi/usercalls/mod.rs  |  2 ++
 .../std/src/sys/sgx/abi/usercalls/tests.rs    | 30 +++++++++++++++++++
 3 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 library/std/src/sys/sgx/abi/usercalls/tests.rs

diff --git a/library/std/src/sys/sgx/abi/usercalls/alloc.rs b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
index 4c1f279857f9..4ac27e85f8ba 100644
--- a/library/std/src/sys/sgx/abi/usercalls/alloc.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
@@ -317,7 +317,7 @@ where
 /// * The `dst` pointer is null
 /// * The `src` memory range is not in enclave memory
 /// * The `dst` memory range is not in user memory
-unsafe fn copy_to_userspace(src: *const u8, dst: *mut u8, len: usize) {
+pub(crate) unsafe fn copy_to_userspace(src: *const u8, dst: *mut u8, len: usize) {
     unsafe fn copy_bytewise_to_userspace(src: *const u8, dst: *mut u8, len: usize) {
         unsafe {
             let seg_sel: u16 = 0;
diff --git a/library/std/src/sys/sgx/abi/usercalls/mod.rs b/library/std/src/sys/sgx/abi/usercalls/mod.rs
index 2f99abba7766..79d1db5e1c50 100644
--- a/library/std/src/sys/sgx/abi/usercalls/mod.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/mod.rs
@@ -6,6 +6,8 @@ use crate::time::{Duration, Instant};
 pub(crate) mod alloc;
 #[macro_use]
 pub(crate) mod raw;
+#[cfg(test)]
+mod tests;
 
 use self::raw::*;
 
diff --git a/library/std/src/sys/sgx/abi/usercalls/tests.rs b/library/std/src/sys/sgx/abi/usercalls/tests.rs
new file mode 100644
index 000000000000..cbf7d7d54f7a
--- /dev/null
+++ b/library/std/src/sys/sgx/abi/usercalls/tests.rs
@@ -0,0 +1,30 @@
+use super::alloc::copy_to_userspace;
+use super::alloc::User;
+
+#[test]
+fn test_copy_function() {
+    let mut src = [0u8; 100];
+    let mut dst = User::<[u8]>::uninitialized(100);
+
+    for i in 0..src.len() {
+        src[i] = i as _;
+    }
+
+    for size in 0..48 {
+        // For all possible alignment
+        for offset in 0..8 {
+            // overwrite complete dst
+            dst.copy_from_enclave(&[0u8; 100]);
+
+            // Copy src[0..size] to dst + offset
+            unsafe { copy_to_userspace(src.as_ptr(), dst.as_mut_ptr().offset(offset), size) };
+
+            // Verify copy
+            for byte in 0..size {
+                unsafe {
+                    assert_eq!(*dst.as_ptr().offset(offset + byte as isize), src[byte as usize]);
+                }
+            }
+        }
+    }
+}