--- a/libunwind/src/DwarfInstructions.hpp	Mon May 25 11:55:54 2020 +0900
+++ b/libunwind/src/DwarfInstructions.hpp	Tue Jun 08 06:07:14 2021 +0900
@@ -93,7 +93,8 @@
 
   case CFI_Parser<A>::kRegisterInRegister:
     return registers.getRegister((int)savedReg.value);
-
+  case CFI_Parser<A>::kRegisterUndefined:
+    return 0;
   case CFI_Parser<A>::kRegisterUnused:
   case CFI_Parser<A>::kRegisterOffsetFromCFA:
     // FIX ME
@@ -117,6 +118,7 @@
 
   case CFI_Parser<A>::kRegisterIsExpression:
   case CFI_Parser<A>::kRegisterUnused:
+  case CFI_Parser<A>::kRegisterUndefined:
   case CFI_Parser<A>::kRegisterOffsetFromCFA:
   case CFI_Parser<A>::kRegisterInRegister:
     // FIX ME
@@ -140,6 +142,7 @@
 
   case CFI_Parser<A>::kRegisterIsExpression:
   case CFI_Parser<A>::kRegisterUnused:
+  case CFI_Parser<A>::kRegisterUndefined:
   case CFI_Parser<A>::kRegisterOffsetFromCFA:
   case CFI_Parser<A>::kRegisterInRegister:
     // FIX ME
@@ -190,6 +193,10 @@
                                     prolog.savedRegisters[i]));
           else
             return UNW_EBADREG;
+        } else if (i == (int)cieInfo.returnAddressRegister) {
+            // Leaf function keeps the return address in register and there is no
+            // explicit intructions how to restore it.
+            returnAddress = registers.getRegister(cieInfo.returnAddressRegister);
         }
       }
 
@@ -206,7 +213,8 @@
       // restored. autia1716 is used instead of autia as autia1716 assembles
       // to a NOP on pre-v8.3a architectures.
       if ((R::getArch() == REGISTERS_ARM64) &&
-          prolog.savedRegisters[UNW_ARM64_RA_SIGN_STATE].value) {
+          prolog.savedRegisters[UNW_ARM64_RA_SIGN_STATE].value &&
+          returnAddress != 0) {
 #if !defined(_LIBUNWIND_IS_NATIVE_ONLY)
         return UNW_ECROSSRASIGNING;
 #else