[asan] fix a bug (issue 19) where dlclose and the following mmap caused a false positive. compiler part.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146688 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 4d6e74b..e4f1978 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -55,8 +55,11 @@
static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;
static const char *kAsanModuleCtorName = "asan.module_ctor";
+static const char *kAsanModuleDtorName = "asan.module_dtor";
+static const int kAsanCtorAndCtorPriority = 1;
static const char *kAsanReportErrorTemplate = "__asan_report_";
static const char *kAsanRegisterGlobalsName = "__asan_register_globals";
+static const char *kAsanUnregisterGlobalsName = "__asan_unregister_globals";
static const char *kAsanInitName = "__asan_init";
static const char *kAsanMappingOffsetName = "__asan_mapping_offset";
static const char *kAsanMappingScaleName = "__asan_mapping_scale";
@@ -559,6 +562,22 @@
IRB.CreatePointerCast(AllGlobals, IntptrTy),
ConstantInt::get(IntptrTy, n));
+ // We also need to unregister globals at the end, e.g. when a shared library
+ // gets closed.
+ Function *AsanDtorFunction = Function::Create(
+ FunctionType::get(Type::getVoidTy(*C), false),
+ GlobalValue::InternalLinkage, kAsanModuleDtorName, &M);
+ BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
+ IRBuilder<> IRB_Dtor(ReturnInst::Create(*C, AsanDtorBB));
+ Function *AsanUnregisterGlobals = cast<Function>(M.getOrInsertFunction(
+ kAsanUnregisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
+ AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
+
+ IRB_Dtor.CreateCall2(AsanUnregisterGlobals,
+ IRB.CreatePointerCast(AllGlobals, IntptrTy),
+ ConstantInt::get(IntptrTy, n));
+ appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndCtorPriority);
+
DEBUG(dbgs() << M);
return true;
}
@@ -632,7 +651,7 @@
Res |= handleFunction(M, *F);
}
- appendToGlobalCtors(M, AsanCtorFunction, 1 /*high priority*/);
+ appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndCtorPriority);
return Res;
}
diff --git a/lib/Transforms/Utils/ModuleUtils.cpp b/lib/Transforms/Utils/ModuleUtils.cpp
index 5e294a3..8491c55 100644
--- a/lib/Transforms/Utils/ModuleUtils.cpp
+++ b/lib/Transforms/Utils/ModuleUtils.cpp
@@ -19,7 +19,8 @@
using namespace llvm;
-void llvm::appendToGlobalCtors(Module &M, Function *F, int Priority) {
+static void appendToGlobalArray(const char *Array,
+ Module &M, Function *F, int Priority) {
IRBuilder<> IRB(M.getContext());
FunctionType *FnTy = FunctionType::get(IRB.getVoidTy(), false);
StructType *Ty = StructType::get(
@@ -31,7 +32,7 @@
// Get the current set of static global constructors and add the new ctor
// to the list.
SmallVector<Constant *, 16> CurrentCtors;
- if (GlobalVariable * GVCtor = M.getNamedGlobal("llvm.global_ctors")) {
+ if (GlobalVariable * GVCtor = M.getNamedGlobal(Array)) {
if (Constant *Init = GVCtor->getInitializer()) {
unsigned n = Init->getNumOperands();
CurrentCtors.reserve(n + 1);
@@ -51,6 +52,13 @@
// Create the new global variable and replace all uses of
// the old global variable with the new one.
(void)new GlobalVariable(M, NewInit->getType(), false,
- GlobalValue::AppendingLinkage, NewInit,
- "llvm.global_ctors");
+ GlobalValue::AppendingLinkage, NewInit, Array);
+}
+
+void llvm::appendToGlobalCtors(Module &M, Function *F, int Priority) {
+ appendToGlobalArray("llvm.global_ctors", M, F, Priority);
+}
+
+void llvm::appendToGlobalDtors(Module &M, Function *F, int Priority) {
+ appendToGlobalArray("llvm.global_dtors", M, F, Priority);
}