diff options
| -rw-r--r-- | include/llvm/CodeGen/StackProtector.h | 97 | ||||
| -rw-r--r-- | lib/CodeGen/StackProtector.cpp | 71 |
2 files changed, 98 insertions, 70 deletions
diff --git a/include/llvm/CodeGen/StackProtector.h b/include/llvm/CodeGen/StackProtector.h new file mode 100644 index 0000000..d23a9d0 --- /dev/null +++ b/include/llvm/CodeGen/StackProtector.h @@ -0,0 +1,97 @@ +//===-- StackProtector.h - Stack Protector Insertion ----------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This pass inserts stack protectors into functions which need them. A variable +// with a random value in it is stored onto the stack before the local variables +// are allocated. Upon exiting the block, the stored value is checked. If it's +// changed, then there was some sort of violation and the program aborts. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CODEGEN_STACKPROTECTOR_H +#define LLVM_CODEGEN_STACKPROTECTOR_H + +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/Triple.h" +#include "llvm/Pass.h" +#include "llvm/Target/TargetLowering.h" + +namespace llvm { +class DominatorTree; +class Function; +class Module; +class PHINode; + +class StackProtector : public FunctionPass { + const TargetMachine *TM; + + /// TLI - Keep a pointer of a TargetLowering to consult for determining + /// target type sizes. + const TargetLoweringBase *TLI; + const Triple Trip; + + Function *F; + Module *M; + + DominatorTree *DT; + + /// \brief The minimum size of buffers that will receive stack smashing + /// protection when -fstack-protection is used. + unsigned SSPBufferSize; + + /// VisitedPHIs - The set of PHI nodes visited when determining + /// if a variable's reference has been taken. This set + /// is maintained to ensure we don't visit the same PHI node multiple + /// times. + SmallPtrSet<const PHINode*, 16> VisitedPHIs; + + /// InsertStackProtectors - Insert code into the prologue and epilogue of + /// the function. + /// + /// - The prologue code loads and stores the stack guard onto the stack. + /// - The epilogue checks the value stored in the prologue against the + /// original value. It calls __stack_chk_fail if they differ. + bool InsertStackProtectors(); + + /// CreateFailBB - Create a basic block to jump to when the stack protector + /// check fails. + BasicBlock *CreateFailBB(); + + /// ContainsProtectableArray - Check whether the type either is an array or + /// contains an array of sufficient size so that we need stack protectors + /// for it. + bool ContainsProtectableArray(Type *Ty, bool Strong = false, + bool InStruct = false) const; + + /// \brief Check whether a stack allocation has its address taken. + bool HasAddressTaken(const Instruction *AI); + + /// RequiresStackProtector - Check whether or not this function needs a + /// stack protector based upon the stack protector level. + bool RequiresStackProtector(); +public: + static char ID; // Pass identification, replacement for typeid. + StackProtector() : FunctionPass(ID), TM(0), TLI(0), SSPBufferSize(0) { + initializeStackProtectorPass(*PassRegistry::getPassRegistry()); + } + StackProtector(const TargetMachine *TM) + : FunctionPass(ID), TM(TM), TLI(0), Trip(TM->getTargetTriple()), + SSPBufferSize(8) { + initializeStackProtectorPass(*PassRegistry::getPassRegistry()); + } + + virtual void getAnalysisUsage(AnalysisUsage &AU) const { + AU.addPreserved<DominatorTree>(); + } + + virtual bool runOnFunction(Function &Fn); +}; +} // end namespace llvm + +#endif // LLVM_CODEGEN_STACKPROTECTOR_H diff --git a/lib/CodeGen/StackProtector.cpp b/lib/CodeGen/StackProtector.cpp index f65b617..cb22082 100644 --- a/lib/CodeGen/StackProtector.cpp +++ b/lib/CodeGen/StackProtector.cpp @@ -15,11 +15,11 @@ //===----------------------------------------------------------------------===// #define DEBUG_TYPE "stack-protector" +#include "llvm/CodeGen/StackProtector.h" #include "llvm/CodeGen/Analysis.h" #include "llvm/CodeGen/Passes.h" #include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/Statistic.h" -#include "llvm/ADT/Triple.h" #include "llvm/Analysis/Dominators.h" #include "llvm/Analysis/ValueTracking.h" #include "llvm/IR/Attributes.h" @@ -34,9 +34,7 @@ #include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/Intrinsics.h" #include "llvm/IR/Module.h" -#include "llvm/Pass.h" #include "llvm/Support/CommandLine.h" -#include "llvm/Target/TargetLowering.h" #include <cstdlib> using namespace llvm; @@ -48,73 +46,6 @@ static cl::opt<bool> EnableSelectionDAGSP("enable-selectiondag-sp", cl::init(true), cl::Hidden); -namespace { - class StackProtector : public FunctionPass { - const TargetMachine *TM; - - /// TLI - Keep a pointer of a TargetLowering to consult for determining - /// target type sizes. - const TargetLoweringBase *TLI; - const Triple Trip; - - Function *F; - Module *M; - - DominatorTree *DT; - - /// \brief The minimum size of buffers that will receive stack smashing - /// protection when -fstack-protection is used. - unsigned SSPBufferSize; - - /// VisitedPHIs - The set of PHI nodes visited when determining - /// if a variable's reference has been taken. This set - /// is maintained to ensure we don't visit the same PHI node multiple - /// times. - SmallPtrSet<const PHINode*, 16> VisitedPHIs; - - /// InsertStackProtectors - Insert code into the prologue and epilogue of - /// the function. - /// - /// - The prologue code loads and stores the stack guard onto the stack. - /// - The epilogue checks the value stored in the prologue against the - /// original value. It calls __stack_chk_fail if they differ. - bool InsertStackProtectors(); - - /// CreateFailBB - Create a basic block to jump to when the stack protector - /// check fails. - BasicBlock *CreateFailBB(); - - /// ContainsProtectableArray - Check whether the type either is an array or - /// contains an array of sufficient size so that we need stack protectors - /// for it. - bool ContainsProtectableArray(Type *Ty, bool Strong = false, - bool InStruct = false) const; - - /// \brief Check whether a stack allocation has its address taken. - bool HasAddressTaken(const Instruction *AI); - - /// RequiresStackProtector - Check whether or not this function needs a - /// stack protector based upon the stack protector level. - bool RequiresStackProtector(); - public: - static char ID; // Pass identification, replacement for typeid. - StackProtector() : FunctionPass(ID), TM(0), TLI(0), SSPBufferSize(0) { - initializeStackProtectorPass(*PassRegistry::getPassRegistry()); - } - StackProtector(const TargetMachine *TM) - : FunctionPass(ID), TM(TM), TLI(0), Trip(TM->getTargetTriple()), - SSPBufferSize(8) { - initializeStackProtectorPass(*PassRegistry::getPassRegistry()); - } - - virtual void getAnalysisUsage(AnalysisUsage &AU) const { - AU.addPreserved<DominatorTree>(); - } - - virtual bool runOnFunction(Function &Fn); - }; -} // end anonymous namespace - char StackProtector::ID = 0; INITIALIZE_PASS(StackProtector, "stack-protector", "Insert stack protectors", false, false) |