From 25a8b809a074941e52cf357674b4382437aabb08 Mon Sep 17 00:00:00 2001 From: Kostya Serebryany Date: Fri, 9 Dec 2011 22:09:32 +0000 Subject: [PATCH] [asan] call __asan_init from .preinit_array. This simplifies __asan_init vs malloc chicken-and-egg situation on Android and probably on other flavours of Linux. Patch by eugenis@google.com. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146284 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../Instrumentation/AddressSanitizer.cpp | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp index 83be31eada6..fdea1b59466 100644 --- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp +++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp @@ -163,6 +163,8 @@ struct AddressSanitizer : public ModulePass { private: + void appendToPreinitArray(Module &M, Function *F); + uint64_t getAllocaSizeInBytes(AllocaInst *AI) { Type *Ty = AI->getAllocatedType(); uint64_t SizeInBytes = TD->getTypeStoreSizeInBits(Ty) / 8; @@ -563,6 +565,18 @@ bool AddressSanitizer::insertGlobalRedzones(Module &M) { return true; } +// .preinit_array is something that hapens before all other inits. +// On systems where .preinit_array is honored, we will call __asan_init early. +// On other systems this will make no effect. +void AddressSanitizer::appendToPreinitArray(Module &M, Function *F) { + IRBuilder<> IRB(M.getContext()); + GlobalVariable *Var = + new GlobalVariable(M, PointerType::getUnqual(F->getFunctionType()), + false, GlobalValue::PrivateLinkage, + F, "__asan_preinit_private"); + Var->setSection(".preinit_array"); +} + // virtual bool AddressSanitizer::runOnModule(Module &M) { // Initialize the private fields. No one has accessed them before. @@ -633,6 +647,7 @@ bool AddressSanitizer::runOnModule(Module &M) { } appendToGlobalCtors(M, AsanCtorFunction, 1 /*high priority*/); + appendToPreinitArray(M, AsanInitFunction); return Res; }