[asan] when creating string constants, set unnamed_attr and align 1 so that equal...

[oota-llvm.git] / lib / Transforms / Instrumentation / AddressSanitizer.cpp

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index f116657192b22a63ed2af8843737c93776bb656b..92b42ee64b008de130a50b56748f162dae80e621 100644 (file)
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -71,7 +71,7 @@ static const char *kAsanRegisterGlobalsName = "__asan_register_globals";
 static const char *kAsanUnregisterGlobalsName = "__asan_unregister_globals";
 static const char *kAsanPoisonGlobalsName = "__asan_before_dynamic_init";
 static const char *kAsanUnpoisonGlobalsName = "__asan_after_dynamic_init";
-static const char *kAsanInitName = "__asan_init_v1";
+static const char *kAsanInitName = "__asan_init_v2";
 static const char *kAsanHandleNoReturnName = "__asan_handle_no_return";
 static const char *kAsanMappingOffsetName = "__asan_mapping_offset";
 static const char *kAsanMappingScaleName = "__asan_mapping_scale";
@@ -244,7 +244,7 @@ static size_t RedzoneSizeForScale(int MappingScale) {
 
 /// AddressSanitizer: instrument the code in module to find memory bugs.
 struct AddressSanitizer : public FunctionPass {
-  AddressSanitizer(bool CheckInitOrder = false,
+  AddressSanitizer(bool CheckInitOrder = true,
                    bool CheckUseAfterReturn = false,
                    bool CheckLifetime = false,
                    StringRef BlacklistFile = StringRef(),
@@ -315,7 +315,7 @@ struct AddressSanitizer : public FunctionPass {
 
 class AddressSanitizerModule : public ModulePass {
  public:
-  AddressSanitizerModule(bool CheckInitOrder = false,
+  AddressSanitizerModule(bool CheckInitOrder = true,
                          StringRef BlacklistFile = StringRef(),
                          bool ZeroBaseShadow = false)
       : ModulePass(ID),
@@ -531,9 +531,12 @@ static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
 // Create a constant for Str so that we can pass it to the run-time lib.
 static GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str) {
   Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
-  return new GlobalVariable(M, StrConst->getType(), true,
+  GlobalVariable *GV = new GlobalVariable(M, StrConst->getType(), true,
                             GlobalValue::PrivateLinkage, StrConst,
                             kAsanGenPrefix);
+  GV->setUnnamedAddr(true);  // Ok to merge these.
+  GV->setAlignment(1);  // Strings may not be merged w/o setting align 1.
+  return GV;
 }
 
 static bool GlobalWasGeneratedByAsan(GlobalVariable *G) {
@@ -885,11 +888,12 @@ bool AddressSanitizerModule::runOnModule(Module &M) {
   //   size_t size;
   //   size_t size_with_redzone;
   //   const char *name;
+  //   const char *module_name;
   //   size_t has_dynamic_init;
   // We initialize an array of such structures and pass it to a run-time call.
   StructType *GlobalStructTy = StructType::get(IntptrTy, IntptrTy,
                                                IntptrTy, IntptrTy,
-                                               IntptrTy, NULL);
+                                               IntptrTy, IntptrTy, NULL);
   SmallVector<Constant *, 16> Initializers(n), DynamicInit;
 
 
@@ -901,6 +905,9 @@ bool AddressSanitizerModule::runOnModule(Module &M) {
   // this TU.  Used in initialization order checking.
   Value *FirstDynamic = 0, *LastDynamic = 0;
 
+  GlobalVariable *ModuleName = createPrivateGlobalForString(
+      M, M.getModuleIdentifier());
+
   for (size_t i = 0; i < n; i++) {
     static const uint64_t kMaxGlobalRedzone = 1 << 18;
     GlobalVariable *G = GlobalsToChange[i];
@@ -930,11 +937,7 @@ bool AddressSanitizerModule::runOnModule(Module &M) {
         NewTy, G->getInitializer(),
         Constant::getNullValue(RightRedZoneTy), NULL);
 
-    SmallString<2048> DescriptionOfGlobal = G->getName();
-    DescriptionOfGlobal += " (";
-    DescriptionOfGlobal += M.getModuleIdentifier();
-    DescriptionOfGlobal += ")";
-    GlobalVariable *Name = createPrivateGlobalForString(M, DescriptionOfGlobal);
+    GlobalVariable *Name = createPrivateGlobalForString(M, G->getName());
 
     // Create a new global variable with enough space for a redzone.
     GlobalVariable *NewGlobal = new GlobalVariable(
@@ -958,6 +961,7 @@ bool AddressSanitizerModule::runOnModule(Module &M) {
         ConstantInt::get(IntptrTy, SizeInBytes),
         ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
         ConstantExpr::getPointerCast(Name, IntptrTy),
+        ConstantExpr::getPointerCast(ModuleName, IntptrTy),
         ConstantInt::get(IntptrTy, GlobalHasDynamicInitializer),
         NULL);
 
@@ -1095,14 +1099,15 @@ bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
 bool AddressSanitizer::runOnFunction(Function &F) {
   if (BL->isIn(F)) return false;
   if (&F == AsanCtorFunction) return false;
+  if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
   DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
   initializeCallbacks(*F.getParent());
 
-  // If needed, insert __asan_init before checking for AddressSafety attr.
+  // If needed, insert __asan_init before checking for SanitizeAddress attr.
   maybeInsertAsanInitAtFunctionEntry(F);
 
   if (!F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
-                                      Attribute::AddressSafety))
+                                      Attribute::SanitizeAddress))
     return false;
 
   if (!ClDebugFunc.empty() && ClDebugFunc != F.getName())