From cd1aba8b4dba01c15b90bd0a2a99750140e627e6 Mon Sep 17 00:00:00 2001 From: Kostya Serebryany Date: Thu, 15 Dec 2011 21:59:03 +0000 Subject: [asan] fix a bug (issue 19) where dlclose and the following mmap caused a false positive. compiler part. llvm-svn: 146688 --- .../Transforms/Instrumentation/AddressSanitizer.cpp | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp') diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp index 4d6e74b8334..e4f197853ef 100644 --- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp +++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp @@ -55,8 +55,11 @@ static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3; 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 @@ bool AddressSanitizer::insertGlobalRedzones(Module &M) { 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(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 @@ bool AddressSanitizer::runOnModule(Module &M) { Res |= handleFunction(M, *F); } - appendToGlobalCtors(M, AsanCtorFunction, 1 /*high priority*/); + appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndCtorPriority); return Res; } -- cgit v1.2.3