X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=lib%2FTransforms%2FInstrumentation%2FDataFlowSanitizer.cpp;h=c5a4860781b9f92fceb810544757fc6b44fe1f19;hp=cb84fd672667e457cea0ceb616aa8ba347843257;hb=7cc4447ccfa69e76cb8e3e3cc76984895421dba5;hpb=5f3c0bafeb9dcceb224d73ca3e76f875321d1ef1

diff --git a/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
index cb84fd67266..c5a4860781b 100644
--- a/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
@@ -234,12 +234,14 @@ class DataFlowSanitizer : public ModulePass {
   FunctionType *DFSanUnimplementedFnTy;
   FunctionType *DFSanSetLabelFnTy;
   FunctionType *DFSanNonzeroLabelFnTy;
+  FunctionType *DFSanVarargWrapperFnTy;
   Constant *DFSanUnionFn;
   Constant *DFSanCheckedUnionFn;
   Constant *DFSanUnionLoadFn;
   Constant *DFSanUnimplementedFn;
   Constant *DFSanSetLabelFn;
   Constant *DFSanNonzeroLabelFn;
+  Constant *DFSanVarargWrapperFn;
   MDNode *ColdCallWeights;
   DFSanABIList ABIList;
   DenseMap<Value *, Function *> UnwrappedFnMap;
@@ -389,12 +391,6 @@ FunctionType *DataFlowSanitizer::getTrampolineFunctionType(FunctionType *T) {
 }
 
 FunctionType *DataFlowSanitizer::getCustomFunctionType(FunctionType *T) {
-  if (T->isVarArg()) {
-    // The labels are passed after all the arguments so there is no need to
-    // adjust the function type.
-    return T;
-  }
-
   llvm::SmallVector<Type *, 4> ArgTypes;
   for (FunctionType::param_iterator i = T->param_begin(), e = T->param_end();
        i != e; ++i) {
@@ -409,10 +405,12 @@ FunctionType *DataFlowSanitizer::getCustomFunctionType(FunctionType *T) {
   }
   for (unsigned i = 0, e = T->getNumParams(); i != e; ++i)
     ArgTypes.push_back(ShadowTy);
+  if (T->isVarArg())
+    ArgTypes.push_back(ShadowPtrTy);
   Type *RetType = T->getReturnType();
   if (!RetType->isVoidTy())
     ArgTypes.push_back(ShadowPtrTy);
-  return FunctionType::get(T->getReturnType(), ArgTypes, false);
+  return FunctionType::get(T->getReturnType(), ArgTypes, T->isVarArg());
 }
 
 bool DataFlowSanitizer::doInitialization(Module &M) {
@@ -443,6 +441,8 @@ bool DataFlowSanitizer::doInitialization(Module &M) {
                                         DFSanSetLabelArgs, /*isVarArg=*/false);
   DFSanNonzeroLabelFnTy = FunctionType::get(
       Type::getVoidTy(*Ctx), None, /*isVarArg=*/false);
+  DFSanVarargWrapperFnTy = FunctionType::get(
+      Type::getVoidTy(*Ctx), Type::getInt8PtrTy(*Ctx), /*isVarArg=*/false);
 
   if (GetArgTLSPtr) {
     Type *ArgTLSTy = ArrayType::get(ShadowTy, 64);
@@ -522,15 +522,26 @@ DataFlowSanitizer::buildWrapperFunction(Function *F, StringRef NewFName,
                                        AttributeSet::ReturnIndex));
 
   BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", NewF);
-  std::vector<Value *> Args;
-  unsigned n = FT->getNumParams();
-  for (Function::arg_iterator ai = NewF->arg_begin(); n != 0; ++ai, --n)
-    Args.push_back(&*ai);
-  CallInst *CI = CallInst::Create(F, Args, "", BB);
-  if (FT->getReturnType()->isVoidTy())
-    ReturnInst::Create(*Ctx, BB);
-  else
-    ReturnInst::Create(*Ctx, CI, BB);
+  if (F->isVarArg()) {
+    NewF->removeAttributes(
+        AttributeSet::FunctionIndex,
+        AttributeSet().addAttribute(*Ctx, AttributeSet::FunctionIndex,
+                                    "split-stack"));
+    CallInst::Create(DFSanVarargWrapperFn,
+                     IRBuilder<>(BB).CreateGlobalStringPtr(F->getName()), "",
+                     BB);
+    new UnreachableInst(*Ctx, BB);
+  } else {
+    std::vector<Value *> Args;
+    unsigned n = FT->getNumParams();
+    for (Function::arg_iterator ai = NewF->arg_begin(); n != 0; ++ai, --n)
+      Args.push_back(&*ai);
+    CallInst *CI = CallInst::Create(F, Args, "", BB);
+    if (FT->getReturnType()->isVoidTy())
+      ReturnInst::Create(*Ctx, BB);
+    else
+      ReturnInst::Create(*Ctx, CI, BB);
+  }
 
   return NewF;
 }
@@ -621,6 +632,8 @@ bool DataFlowSanitizer::runOnModule(Module &M) {
   }
   DFSanNonzeroLabelFn =
       Mod->getOrInsertFunction("__dfsan_nonzero_label", DFSanNonzeroLabelFnTy);
+  DFSanVarargWrapperFn = Mod->getOrInsertFunction("__dfsan_vararg_wrapper",
+                                                  DFSanVarargWrapperFnTy);
 
   std::vector<Function *> FnsToInstrument;
   llvm::SmallPtrSet<Function *, 2> FnsWithNativeABI;
@@ -631,7 +644,8 @@ bool DataFlowSanitizer::runOnModule(Module &M) {
         i != DFSanUnionLoadFn &&
         i != DFSanUnimplementedFn &&
         i != DFSanSetLabelFn &&
-        i != DFSanNonzeroLabelFn)
+        i != DFSanNonzeroLabelFn &&
+        i != DFSanVarargWrapperFn)
       FnsToInstrument.push_back(&*i);
   }
 
@@ -1367,6 +1381,11 @@ void DFSanVisitor::visitCallSite(CallSite CS) {
     return;
   }
 
+  // Calls to this function are synthesized in wrappers, and we shouldn't
+  // instrument them.
+  if (F == DFSF.DFS.DFSanVarargWrapperFn)
+    return;
+
   assert(!(cast<FunctionType>(
       CS.getCalledValue()->getType()->getPointerElementType())->isVarArg() &&
            dyn_cast<InvokeInst>(CS.getInstruction())));
@@ -1419,7 +1438,7 @@ void DFSanVisitor::visitCallSite(CallSite CS) {
         std::vector<Value *> Args;
 
         CallSite::arg_iterator i = CS.arg_begin();
-        for (unsigned n = CS.arg_size(); n != 0; ++i, --n) {
+        for (unsigned n = FT->getNumParams(); n != 0; ++i, --n) {
           Type *T = (*i)->getType();
           FunctionType *ParamFT;
           if (isa<PointerType>(T) &&
@@ -1439,9 +1458,23 @@ void DFSanVisitor::visitCallSite(CallSite CS) {
         }
 
         i = CS.arg_begin();
-        for (unsigned n = CS.arg_size(); n != 0; ++i, --n)
+        for (unsigned n = FT->getNumParams(); n != 0; ++i, --n)
           Args.push_back(DFSF.getShadow(*i));
 
+        if (FT->isVarArg()) {
+          auto LabelVAAlloca =
+              new AllocaInst(ArrayType::get(DFSF.DFS.ShadowTy,
+                                            CS.arg_size() - FT->getNumParams()),
+                             "labelva", DFSF.F->getEntryBlock().begin());
+
+          for (unsigned n = 0; i != CS.arg_end(); ++i, ++n) {
+            auto LabelVAPtr = IRB.CreateStructGEP(LabelVAAlloca, n);
+            IRB.CreateStore(DFSF.getShadow(*i), LabelVAPtr);
+          }
+
+          Args.push_back(IRB.CreateStructGEP(LabelVAAlloca, 0));
+        }
+
         if (!FT->getReturnType()->isVoidTy()) {
           if (!DFSF.LabelReturnAlloca) {
             DFSF.LabelReturnAlloca =
@@ -1451,6 +1484,9 @@ void DFSanVisitor::visitCallSite(CallSite CS) {
           Args.push_back(DFSF.LabelReturnAlloca);
         }
 
+        for (i = CS.arg_begin() + FT->getNumParams(); i != CS.arg_end(); ++i)
+          Args.push_back(*i);
+
         CallInst *CustomCI = IRB.CreateCall(CustomF, Args);
         CustomCI->setCallingConv(CI->getCallingConv());
         CustomCI->setAttributes(CI->getAttributes());