1 files changed, 67 insertions, 0 deletions
diff --git a/lib/hwasan/hwasan_exceptions.cpp b/lib/hwasan/hwasan_exceptions.cpp
new file mode 100644
index 000000000000..169e7876cb58
--- /dev/null
+++ b/lib/hwasan/hwasan_exceptions.cpp
@@ -0,0 +1,67 @@
+//===-- hwasan_exceptions.cpp ---------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of HWAddressSanitizer.
+//
+// HWAddressSanitizer runtime.
+//===----------------------------------------------------------------------===//
+
+#include "hwasan_poisoning.h"
+#include "sanitizer_common/sanitizer_common.h"
+
+#include <unwind.h>
+
+using namespace __hwasan;
+using namespace __sanitizer;
+
+typedef _Unwind_Reason_Code PersonalityFn(int version, _Unwind_Action actions,
+                                          uint64_t exception_class,
+                                          _Unwind_Exception* unwind_exception,
+                                          _Unwind_Context* context);
+
+// Pointers to the _Unwind_GetGR and _Unwind_GetCFA functions are passed in
+// instead of being called directly. This is to handle cases where the unwinder
+// is statically linked and the sanitizer runtime and the program are linked
+// against different unwinders. The _Unwind_Context data structure is opaque so
+// it may be incompatible between unwinders.
+typedef _Unwind_Word GetGRFn(_Unwind_Context* context, int index);
+typedef _Unwind_Word GetCFAFn(_Unwind_Context* context);
+
+extern "C" SANITIZER_INTERFACE_ATTRIBUTE _Unwind_Reason_Code
+__hwasan_personality_wrapper(int version, _Unwind_Action actions,
+                             uint64_t exception_class,
+                             _Unwind_Exception* unwind_exception,
+                             _Unwind_Context* context,
+                             PersonalityFn* real_personality, GetGRFn* get_gr,
+                             GetCFAFn* get_cfa) {
+  _Unwind_Reason_Code rc;
+  if (real_personality)
+    rc = real_personality(version, actions, exception_class, unwind_exception,
+                          context);
+  else
+    rc = _URC_CONTINUE_UNWIND;
+
+  // We only untag frames without a landing pad because landing pads are
+  // responsible for untagging the stack themselves if they resume.
+  //
+  // Here we assume that the frame record appears after any locals. This is not
+  // required by AAPCS but is a requirement for HWASAN instrumented functions.
+  if ((actions & _UA_CLEANUP_PHASE) && rc == _URC_CONTINUE_UNWIND) {
+#if defined(__x86_64__)
+    uptr fp = get_gr(context, 6); // rbp
+#elif defined(__aarch64__)
+    uptr fp = get_gr(context, 29); // x29
+#else
+#error Unsupported architecture
+#endif
+    uptr sp = get_cfa(context);
+    TagMemory(sp, fp - sp, 0);
+  }
+
+  return rc;
+}