1 files changed, 72 insertions, 0 deletions
diff --git a/test/builtins/Unit/enable_execute_stack_test.c b/test/builtins/Unit/enable_execute_stack_test.c
new file mode 100644
index 0000000000000..c0f67b3379396
--- /dev/null
+++ b/test/builtins/Unit/enable_execute_stack_test.c
@@ -0,0 +1,72 @@
+//===-- enable_execute_stack_test.c - Test __enable_execute_stack ----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#if defined(_WIN32)
+#include <windows.h>
+void __clear_cache(void* start, void* end)
+{
+    if (!FlushInstructionCache(GetCurrentProcess(), start, end-start))
+        exit(1);
+}
+void __enable_execute_stack(void *addr)
+{
+    MEMORY_BASIC_INFORMATION b;
+
+    if (!VirtualQuery(addr, &b, sizeof(b)))
+        exit(1);
+    if (!VirtualProtect(b.BaseAddress, b.RegionSize, PAGE_EXECUTE_READWRITE, &b.Protect))
+        exit(1);
+}
+#else
+#include <sys/mman.h>
+extern void __clear_cache(void* start, void* end);
+extern void __enable_execute_stack(void* addr);
+#endif
+
+typedef int (*pfunc)(void);
+
+int func1() 
+{
+    return 1;
+}
+
+int func2() 
+{
+    return 2;
+}
+
+
+
+
+int main()
+{
+    unsigned char execution_buffer[128];
+    // mark stack page containing execution_buffer to be executable
+    __enable_execute_stack(execution_buffer);
+	
+    // verify you can copy and execute a function
+    memcpy(execution_buffer, (void *)(uintptr_t)&func1, 128);
+    __clear_cache(execution_buffer, &execution_buffer[128]);
+    pfunc f1 = (pfunc)(uintptr_t)execution_buffer;
+    if ((*f1)() != 1)
+        return 1;
+
+    // verify you can overwrite a function with another
+    memcpy(execution_buffer, (void *)(uintptr_t)&func2, 128);
+    __clear_cache(execution_buffer, &execution_buffer[128]);
+    pfunc f2 = (pfunc)(uintptr_t)execution_buffer;
+    if ((*f2)() != 2)
+        return 1;
+
+    return 0;
+}