diff --git a/llvm/lib/CodeGen/StackProtector.cpp b/llvm/lib/CodeGen/StackProtector.cpp
--- a/llvm/lib/CodeGen/StackProtector.cpp
+++ b/llvm/lib/CodeGen/StackProtector.cpp
@@ -598,11 +598,13 @@
     FunctionCallee StackChkFail = M->getOrInsertFunction(
         "__stack_smash_handler", Type::getVoidTy(Context),
         Type::getInt8PtrTy(Context));
+    cast<Function>(StackChkFail.getCallee())->addFnAttr(Attribute::NoReturn);
 
     B.CreateCall(StackChkFail, B.CreateGlobalStringPtr(F->getName(), "SSH"));
   } else {
     FunctionCallee StackChkFail =
         M->getOrInsertFunction("__stack_chk_fail", Type::getVoidTy(Context));
+    cast<Function>(StackChkFail.getCallee())->addFnAttr(Attribute::NoReturn);
 
     B.CreateCall(StackChkFail, {});
   }
diff --git a/llvm/test/CodeGen/X86/2009-04-14-IllegalRegs.ll b/llvm/test/CodeGen/X86/2009-04-14-IllegalRegs.ll
--- a/llvm/test/CodeGen/X86/2009-04-14-IllegalRegs.ll
+++ b/llvm/test/CodeGen/X86/2009-04-14-IllegalRegs.ll
@@ -53,7 +53,6 @@
 ; CHECK-NEXT:    retl
 ; CHECK-NEXT:  LBB0_3: ## %CallStackCheckFailBlk
 ; CHECK-NEXT:    calll ___stack_chk_fail
-; CHECK-NEXT:    ud2
 entry:
 	%retval = alloca i32		; <ptr> [#uses=2]
 	%xxx = alloca %struct.X		; <ptr> [#uses=6]
diff --git a/llvm/test/CodeGen/X86/stack-protector-weight.ll b/llvm/test/CodeGen/X86/stack-protector-weight.ll
--- a/llvm/test/CodeGen/X86/stack-protector-weight.ll
+++ b/llvm/test/CodeGen/X86/stack-protector-weight.ll
@@ -10,7 +10,7 @@
 ; DARWIN-SELDAG: bb.[[SUCCESS]]{{[0-9a-zA-Z_.]+}}:
 
 ; DARWIN-IR: # Machine code for function test_branch_weights:
-; DARWIN-IR: successors: %bb.[[SUCCESS:[0-9]+]](0x7fffffff), %bb.[[FAILURE:[0-9]+]]
+; DARWIN-IR: successors: %bb.[[SUCCESS:[0-9]+]](0x7ffff800), %bb.[[FAILURE:[0-9]+]]
 ; DARWIN-IR: bb.[[SUCCESS]]{{[0-9a-zA-Z_.]+}}:
 ; DARWIN-IR: bb.[[FAILURE]]{{[0-9a-zA-Z_.]+}}:
 ; DARWIN-IR: CALL64pcrel32 @__stack_chk_fail