1 files changed, 55 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseStackCheckLib/BaseStackCheckGcc.c b/MdePkg/Library/BaseStackCheckLib/BaseStackCheckGcc.c
new file mode 100644
index 000000000000..ad3f2684ce7f
--- /dev/null
+++ b/MdePkg/Library/BaseStackCheckLib/BaseStackCheckGcc.c
@@ -0,0 +1,55 @@
+/** @file
+ Base Stack Check library for GCC/clang.
+
+ Use -fstack-protector-all compiler flag to make the compiler insert the
+ __stack_chk_guard "canary" value into the stack and check the value prior
+ to exiting the function. If the "canary" is overwritten __stack_chk_fail()
+ is called. This is GCC specific code.
+
+ Copyright (c) 2012, Apple Inc. All rights reserved.<BR>
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution.  The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php.
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include <Base.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/PcdLib.h>
+
+/// "canary" value that is inserted by the compiler into the stack frame.
+VOID *__stack_chk_guard = (VOID*)0x0AFF;
+
+// If ASLR was enabled we could use
+//void (*__stack_chk_guard)(void) = __stack_chk_fail;
+
+/**
+ Error path for compiler generated stack "canary" value check code. If the
+ stack canary has been overwritten this function gets called on exit of the
+ function.
+**/
+VOID
+__stack_chk_fail (
+ VOID
+ )
+{
+  UINT8 DebugPropertyMask;
+
+  DEBUG ((DEBUG_ERROR, "STACK FAULT: Buffer Overflow in function %a.\n", __builtin_return_address(0)));
+
+  //
+  // Generate a Breakpoint, DeadLoop, or NOP based on PCD settings even if
+  // BaseDebugLibNull is in use.
+  //
+  DebugPropertyMask = PcdGet8 (PcdDebugPropertyMask);
+  if ((DebugPropertyMask & DEBUG_PROPERTY_ASSERT_BREAKPOINT_ENABLED) != 0) {
+    CpuBreakpoint ();
+  } else if ((DebugPropertyMask & DEBUG_PROPERTY_ASSERT_DEADLOOP_ENABLED) != 0) {
+   CpuDeadLoop ();
+  }
+}