1 files changed, 6 insertions, 56 deletions

diff --git a/contrib/llvm/lib/CodeGen/SafeStack.cpp b/contrib/llvm/lib/CodeGen/SafeStack.cpp
index 4a1b995..2b82df2 100644
--- a/contrib/llvm/lib/CodeGen/SafeStack.cpp
+++ b/contrib/llvm/lib/CodeGen/SafeStack.cpp
@@ -52,17 +52,6 @@ using namespace llvm::safestack;
 
 #define DEBUG_TYPE "safestack"
 
-enum UnsafeStackPtrStorageVal { ThreadLocalUSP, SingleThreadUSP };
-
-static cl::opt<UnsafeStackPtrStorageVal> USPStorage("safe-stack-usp-storage",
-    cl::Hidden, cl::init(ThreadLocalUSP),
-    cl::desc("Type of storage for the unsafe stack pointer"),
-    cl::values(clEnumValN(ThreadLocalUSP, "thread-local",
-                          "Thread-local storage"),
-               clEnumValN(SingleThreadUSP, "single-thread",
-                          "Non-thread-local storage"),
-               clEnumValEnd));
-
 namespace llvm {
 
 STATISTIC(NumFunctions, "Total number of functions");
@@ -124,9 +113,6 @@ class SafeStack : public FunctionPass {
   /// might expect to appear on the stack on most common targets.
   enum { StackAlignment = 16 };
 
-  /// \brief Build a value representing a pointer to the unsafe stack pointer.
-  Value *getOrCreateUnsafeStackPtr(IRBuilder<> &IRB, Function &F);
-
   /// \brief Return the value of the stack canary.
   Value *getStackGuard(IRBuilder<> &IRB, Function &F);
 
@@ -356,46 +342,8 @@ bool SafeStack::IsSafeStackAlloca(const Value *AllocaPtr, uint64_t AllocaSize) {
   return true;
 }
 
-Value *SafeStack::getOrCreateUnsafeStackPtr(IRBuilder<> &IRB, Function &F) {
-  // Check if there is a target-specific location for the unsafe stack pointer.
-  if (TL)
-    if (Value *V = TL->getSafeStackPointerLocation(IRB))
-      return V;
-
-  // Otherwise, assume the target links with compiler-rt, which provides a
-  // thread-local variable with a magic name.
-  Module &M = *F.getParent();
-  const char *UnsafeStackPtrVar = "__safestack_unsafe_stack_ptr";
-  auto UnsafeStackPtr =
-      dyn_cast_or_null<GlobalVariable>(M.getNamedValue(UnsafeStackPtrVar));
-
-  bool UseTLS = USPStorage == ThreadLocalUSP;
-
-  if (!UnsafeStackPtr) {
-    auto TLSModel = UseTLS ?
-        GlobalValue::InitialExecTLSModel :
-        GlobalValue::NotThreadLocal;
-    // The global variable is not defined yet, define it ourselves.
-    // We use the initial-exec TLS model because we do not support the
-    // variable living anywhere other than in the main executable.
-    UnsafeStackPtr = new GlobalVariable(
-        M, StackPtrTy, false, GlobalValue::ExternalLinkage, nullptr,
-        UnsafeStackPtrVar, nullptr, TLSModel);
-  } else {
-    // The variable exists, check its type and attributes.
-    if (UnsafeStackPtr->getValueType() != StackPtrTy)
-      report_fatal_error(Twine(UnsafeStackPtrVar) + " must have void* type");
-    if (UseTLS != UnsafeStackPtr->isThreadLocal())
-      report_fatal_error(Twine(UnsafeStackPtrVar) + " must " +
-                         (UseTLS ? "" : "not ") + "be thread-local");
-  }
-  return UnsafeStackPtr;
-}
-
 Value *SafeStack::getStackGuard(IRBuilder<> &IRB, Function &F) {
-  Value *StackGuardVar = nullptr;
-  if (TL)
-    StackGuardVar = TL->getIRStackGuard(IRB);
+  Value *StackGuardVar = TL->getIRStackGuard(IRB);
   if (!StackGuardVar)
     StackGuardVar =
         F.getParent()->getOrInsertGlobal("__stack_chk_guard", StackPtrTy);
@@ -752,7 +700,9 @@ bool SafeStack::runOnFunction(Function &F) {
     return false;
   }
 
-  TL = TM ? TM->getSubtargetImpl(F)->getTargetLowering() : nullptr;
+  if (!TM)
+    report_fatal_error("Target machine is required");
+  TL = TM->getSubtargetImpl(F)->getTargetLowering();
   SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
 
   ++NumFunctions;
@@ -764,7 +714,7 @@ bool SafeStack::runOnFunction(Function &F) {
 
   // Collect all points where stack gets unwound and needs to be restored
   // This is only necessary because the runtime (setjmp and unwind code) is
-  // not aware of the unsafe stack and won't unwind/restore it prorerly.
+  // not aware of the unsafe stack and won't unwind/restore it properly.
   // To work around this problem without changing the runtime, we insert
   // instrumentation to restore the unsafe stack pointer when necessary.
   SmallVector<Instruction *, 4> StackRestorePoints;
@@ -786,7 +736,7 @@ bool SafeStack::runOnFunction(Function &F) {
     ++NumUnsafeStackRestorePointsFunctions;
 
   IRBuilder<> IRB(&F.front(), F.begin()->getFirstInsertionPt());
-  UnsafeStackPtr = getOrCreateUnsafeStackPtr(IRB, F);
+  UnsafeStackPtr = TL->getSafeStackPointerLocation(IRB);
 
   // Load the current stack pointer (we'll also use it as a base pointer).
   // FIXME: use a dedicated register for it ?