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
@@ -478,11 +478,11 @@
     // we don't need to worry about many situations here.
     Instruction *CheckLoc = RI;
     Instruction *Prev = RI->getPrevNonDebugInstruction();
-    if (Prev && isa<CallInst>(Prev) && cast<CallInst>(Prev)->isMustTailCall())
+    if (Prev && isa<CallInst>(Prev) && cast<CallInst>(Prev)->isTailCall())
       CheckLoc = Prev;
     else if (Prev) {
       Prev = Prev->getPrevNonDebugInstruction();
-      if (Prev && isa<CallInst>(Prev) && cast<CallInst>(Prev)->isMustTailCall())
+      if (Prev && isa<CallInst>(Prev) && cast<CallInst>(Prev)->isTailCall())
         CheckLoc = Prev;
     }
 
diff --git a/llvm/test/CodeGen/AArch64/stack-protector-musttail.ll b/llvm/test/CodeGen/AArch64/stack-protector-tail.ll
rename from llvm/test/CodeGen/AArch64/stack-protector-musttail.ll
rename to llvm/test/CodeGen/AArch64/stack-protector-tail.ll
--- a/llvm/test/CodeGen/AArch64/stack-protector-musttail.ll
+++ b/llvm/test/CodeGen/AArch64/stack-protector-tail.ll
@@ -4,7 +4,7 @@
 
 declare void @callee()
 
-define void @caller1() ssp {
+define void @caller1() sspreq {
 ; CHECK-LABEL: define void @caller1()
 ; Prologue:
 ; CHECK: @llvm.stackguard
@@ -14,15 +14,15 @@
 ; CHECK: [[TST:%.*]] = icmp eq i8* [[GUARD]], [[TOKEN]]
 ; CHECK: br i1 [[TST]]
 
-; CHECK: musttail call void @callee()
+; CHECK: tail call void @callee()
 ; CHECK-NEXT: ret void
   %var = alloca [2 x i64]
   store [2 x i64]* %var, [2 x i64]** @var
-  musttail call void @callee()
+  tail call void @callee()
   ret void
 }
 
-define void @justret() ssp {
+define void @justret() sspreq {
 ; CHECK-LABEL: define void @justret()
 ; Prologue:
 ; CHECK: @llvm.stackguard
@@ -44,7 +44,7 @@
 
 declare i64* @callee2()
 
-define i8* @caller2() ssp {
+define i8* @caller2() sspreq {
 ; CHECK-LABEL: define i8* @caller2()
 ; Prologue:
 ; CHECK: @llvm.stackguard
@@ -54,13 +54,13 @@
 ; CHECK: [[TST:%.*]] = icmp eq i8* [[GUARD]], [[TOKEN]]
 ; CHECK: br i1 [[TST]]
 
-; CHECK: [[TMP:%.*]] = musttail call i64* @callee2()
+; CHECK: [[TMP:%.*]] = tail call i64* @callee2()
 ; CHECK-NEXT: [[RES:%.*]] = bitcast i64* [[TMP]] to i8*
 ; CHECK-NEXT: ret i8* [[RES]]
 
   %var = alloca [2 x i64]
   store [2 x i64]* %var, [2 x i64]** @var
-  %tmp = musttail call i64* @callee2()
+  %tmp = tail call i64* @callee2()
   %res = bitcast i64* %tmp to i8*
   ret i8* %res
 }
diff --git a/llvm/test/CodeGen/ARM/Windows/stack-protector-musttail.ll b/llvm/test/CodeGen/ARM/Windows/stack-protector-tail.ll
rename from llvm/test/CodeGen/ARM/Windows/stack-protector-musttail.ll
rename to llvm/test/CodeGen/ARM/Windows/stack-protector-tail.ll
--- a/llvm/test/CodeGen/ARM/Windows/stack-protector-musttail.ll
+++ b/llvm/test/CodeGen/ARM/Windows/stack-protector-tail.ll
@@ -10,11 +10,11 @@
 
 ; CHECK: call void @__security_check_cookie
 
-; CHECK: musttail call void @callee()
+; CHECK: tail call void @callee()
 ; CHECK-NEXT: ret void
   %var = alloca [2 x i64]
   store [2 x i64]* %var, [2 x i64]** @var
-  musttail call void @callee()
+  tail call void @callee()
   ret void
 }
 
@@ -44,13 +44,13 @@
 
 ; CHECK: call void @__security_check_cookie
 
-; CHECK: [[TMP:%.*]] = musttail call i64* @callee2()
+; CHECK: [[TMP:%.*]] = tail call i64* @callee2()
 ; CHECK-NEXT: [[RES:%.*]] = bitcast i64* [[TMP]] to i8*
 ; CHECK-NEXT: ret i8* [[RES]]
 
   %var = alloca [2 x i64]
   store [2 x i64]* %var, [2 x i64]** @var
-  %tmp = musttail call i64* @callee2()
+  %tmp = tail call i64* @callee2()
   %res = bitcast i64* %tmp to i8*
   ret i8* %res
 }
diff --git a/llvm/test/CodeGen/AArch64/stack-protector-musttail.ll b/llvm/test/CodeGen/X86/stack-protector-tail.ll
rename from llvm/test/CodeGen/AArch64/stack-protector-musttail.ll
rename to llvm/test/CodeGen/X86/stack-protector-tail.ll
--- a/llvm/test/CodeGen/AArch64/stack-protector-musttail.ll
+++ b/llvm/test/CodeGen/X86/stack-protector-tail.ll
@@ -1,33 +1,33 @@
-; RUN: llc -mtriple=arm64-apple-macosx -fast-isel %s -o - -start-before=stack-protector -stop-after=stack-protector  | FileCheck %s
+; RUN: llc -mtriple=x86_64-linux-gnu -fast-isel %s -o - -start-before=stack-protector -stop-after=stack-protector  | FileCheck %s
 
 @var = global [2 x i64]* null
 
 declare void @callee()
 
-define void @caller1() ssp {
+define void @caller1() sspreq {
 ; CHECK-LABEL: define void @caller1()
 ; Prologue:
-; CHECK: @llvm.stackguard
+; CHECK: @llvm.stackprotector
 
-; CHECK: [[GUARD:%.*]] = call i8* @llvm.stackguard()
+; CHECK: [[GUARD:%.*]] = load volatile i8*, i8*
 ; CHECK: [[TOKEN:%.*]] = load volatile i8*, i8** {{%.*}}
 ; CHECK: [[TST:%.*]] = icmp eq i8* [[GUARD]], [[TOKEN]]
 ; CHECK: br i1 [[TST]]
 
-; CHECK: musttail call void @callee()
+; CHECK: tail call void @callee()
 ; CHECK-NEXT: ret void
   %var = alloca [2 x i64]
   store [2 x i64]* %var, [2 x i64]** @var
-  musttail call void @callee()
+  tail call void @callee()
   ret void
 }
 
-define void @justret() ssp {
+define void @justret() sspreq {
 ; CHECK-LABEL: define void @justret()
 ; Prologue:
-; CHECK: @llvm.stackguard
+; CHECK: @llvm.stackprotector
 
-; CHECK: [[GUARD:%.*]] = call i8* @llvm.stackguard()
+; CHECK: [[GUARD:%.*]] = load volatile i8*, i8*
 ; CHECK: [[TOKEN:%.*]] = load volatile i8*, i8** {{%.*}}
 ; CHECK: [[TST:%.*]] = icmp eq i8* [[GUARD]], [[TOKEN]]
 ; CHECK: br i1 [[TST]]
@@ -44,23 +44,23 @@
 
 declare i64* @callee2()
 
-define i8* @caller2() ssp {
+define i8* @caller2() sspreq {
 ; CHECK-LABEL: define i8* @caller2()
 ; Prologue:
-; CHECK: @llvm.stackguard
+; CHECK: @llvm.stackprotector
 
-; CHECK: [[GUARD:%.*]] = call i8* @llvm.stackguard()
+; CHECK: [[GUARD:%.*]] = load volatile i8*, i8*
 ; CHECK: [[TOKEN:%.*]] = load volatile i8*, i8** {{%.*}}
 ; CHECK: [[TST:%.*]] = icmp eq i8* [[GUARD]], [[TOKEN]]
 ; CHECK: br i1 [[TST]]
 
-; CHECK: [[TMP:%.*]] = musttail call i64* @callee2()
+; CHECK: [[TMP:%.*]] = tail call i64* @callee2()
 ; CHECK-NEXT: [[RES:%.*]] = bitcast i64* [[TMP]] to i8*
 ; CHECK-NEXT: ret i8* [[RES]]
 
   %var = alloca [2 x i64]
   store [2 x i64]* %var, [2 x i64]** @var
-  %tmp = musttail call i64* @callee2()
+  %tmp = tail call i64* @callee2()
   %res = bitcast i64* %tmp to i8*
   ret i8* %res
 }
diff --git a/llvm/test/CodeGen/X86/tailcc-ssp.ll b/llvm/test/CodeGen/X86/tailcc-ssp.ll
--- a/llvm/test/CodeGen/X86/tailcc-ssp.ll
+++ b/llvm/test/CodeGen/X86/tailcc-ssp.ll
@@ -1,12 +1,18 @@
-; RUN: llc -mtriple=x86_64-windows-msvc %s -o - -verify-machineinstrs | FileCheck %s
+; RUN: llc -mtriple=x86_64-windows-msvc %s -o - -verify-machineinstrs | FileCheck %s -check-prefix=WINDOWS
+; RUN: llc -mtriple=x86_64-linux-gnu    %s -o - -verify-machineinstrs | FileCheck %s -check-prefix=LINUX
 
 declare void @h(ptr, i64, ptr)
 
 define tailcc void @tailcall_frame(ptr %0, i64 %1) sspreq {
-; CHECK-LABEL: tailcall_frame:
-; CHECK: callq __security_check_cookie
-; CHECK: xorl %ecx, %ecx
-; CHECK: jmp h
+; WINDOWS-LABEL: tailcall_frame:
+; WINDOWS: callq __security_check_cookie
+; WINDOWS: xorl %ecx, %ecx
+; WINDOWS: jmp h
+
+; LINUX-LABEL: tailcall_frame:
+; LINUX: jne
+; LINUX: jmp h
+; LINUX: callq __stack_chk_fail
 
    tail call tailcc void @h(ptr null, i64 0, ptr null)
    ret void
@@ -14,12 +20,19 @@
 
 declare void @bar()
 define void @tailcall_unrelated_frame() sspreq {
-; CHECK-LABEL: tailcall_unrelated_frame:
-; CHECK: subq [[STACK:\$.*]], %rsp
-; CHECK: callq bar
-; CHECK: callq __security_check_cookie
-; CHECK: addq [[STACK]], %rsp
-; CHECK: jmp bar
+; WINDOWS-LABEL: tailcall_unrelated_frame:
+; WINDOWS: subq [[STACK:\$.*]], %rsp
+; WINDOWS: callq bar
+; WINDOWS: callq __security_check_cookie
+; WINDOWS: addq [[STACK]], %rsp
+; WINDOWS: jmp bar
+
+; LINUX-LABEL: tailcall_unrelated_frame:
+; LINUX: callq bar
+; LINUX: jne
+; LINUX: jmp bar
+; LINUX: callq __stack_chk_fail
+
   call void @bar()
   tail call void @bar()
   ret void