mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-10-20 19:42:54 +02:00
eb66b33867
I did this a long time ago with a janky python script, but now clang-format has built-in support for this. I fed clang-format every line with a #include and let it re-sort things according to the precise LLVM rules for include ordering baked into clang-format these days. I've reverted a number of files where the results of sorting includes isn't healthy. Either places where we have legacy code relying on particular include ordering (where possible, I'll fix these separately) or where we have particular formatting around #include lines that I didn't want to disturb in this patch. This patch is *entirely* mechanical. If you get merge conflicts or anything, just ignore the changes in this patch and run clang-format over your #include lines in the files. Sorry for any noise here, but it is important to keep these things stable. I was seeing an increasing number of patches with irrelevant re-ordering of #include lines because clang-format was used. This patch at least isolates that churn, makes it easy to skip when resolving conflicts, and gets us to a clean baseline (again). llvm-svn: 304787
213 lines
7.1 KiB
C++
213 lines
7.1 KiB
C++
//===- BoundsChecking.cpp - Instrumentation for run-time bounds checking --===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements a pass that instruments the code to perform run-time
|
|
// bounds checking on loads, stores, and other memory intrinsics.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/ADT/Statistic.h"
|
|
#include "llvm/Analysis/MemoryBuiltins.h"
|
|
#include "llvm/Analysis/TargetFolder.h"
|
|
#include "llvm/Analysis/TargetLibraryInfo.h"
|
|
#include "llvm/IR/DataLayout.h"
|
|
#include "llvm/IR/IRBuilder.h"
|
|
#include "llvm/IR/InstIterator.h"
|
|
#include "llvm/IR/Intrinsics.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Support/CommandLine.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
#include "llvm/Transforms/Instrumentation.h"
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "bounds-checking"
|
|
|
|
static cl::opt<bool> SingleTrapBB("bounds-checking-single-trap",
|
|
cl::desc("Use one trap block per function"));
|
|
|
|
STATISTIC(ChecksAdded, "Bounds checks added");
|
|
STATISTIC(ChecksSkipped, "Bounds checks skipped");
|
|
STATISTIC(ChecksUnable, "Bounds checks unable to add");
|
|
|
|
typedef IRBuilder<TargetFolder> BuilderTy;
|
|
|
|
namespace {
|
|
struct BoundsChecking : public FunctionPass {
|
|
static char ID;
|
|
|
|
BoundsChecking() : FunctionPass(ID) {
|
|
initializeBoundsCheckingPass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
bool runOnFunction(Function &F) override;
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
AU.addRequired<TargetLibraryInfoWrapperPass>();
|
|
}
|
|
|
|
private:
|
|
const TargetLibraryInfo *TLI;
|
|
ObjectSizeOffsetEvaluator *ObjSizeEval;
|
|
BuilderTy *Builder;
|
|
Instruction *Inst;
|
|
BasicBlock *TrapBB;
|
|
|
|
BasicBlock *getTrapBB();
|
|
void emitBranchToTrap(Value *Cmp = nullptr);
|
|
bool instrument(Value *Ptr, Value *Val, const DataLayout &DL);
|
|
};
|
|
}
|
|
|
|
char BoundsChecking::ID = 0;
|
|
INITIALIZE_PASS(BoundsChecking, "bounds-checking", "Run-time bounds checking",
|
|
false, false)
|
|
|
|
|
|
/// getTrapBB - create a basic block that traps. All overflowing conditions
|
|
/// branch to this block. There's only one trap block per function.
|
|
BasicBlock *BoundsChecking::getTrapBB() {
|
|
if (TrapBB && SingleTrapBB)
|
|
return TrapBB;
|
|
|
|
Function *Fn = Inst->getParent()->getParent();
|
|
IRBuilder<>::InsertPointGuard Guard(*Builder);
|
|
TrapBB = BasicBlock::Create(Fn->getContext(), "trap", Fn);
|
|
Builder->SetInsertPoint(TrapBB);
|
|
|
|
llvm::Value *F = Intrinsic::getDeclaration(Fn->getParent(), Intrinsic::trap);
|
|
CallInst *TrapCall = Builder->CreateCall(F, {});
|
|
TrapCall->setDoesNotReturn();
|
|
TrapCall->setDoesNotThrow();
|
|
TrapCall->setDebugLoc(Inst->getDebugLoc());
|
|
Builder->CreateUnreachable();
|
|
|
|
return TrapBB;
|
|
}
|
|
|
|
|
|
/// emitBranchToTrap - emit a branch instruction to a trap block.
|
|
/// If Cmp is non-null, perform a jump only if its value evaluates to true.
|
|
void BoundsChecking::emitBranchToTrap(Value *Cmp) {
|
|
// check if the comparison is always false
|
|
ConstantInt *C = dyn_cast_or_null<ConstantInt>(Cmp);
|
|
if (C) {
|
|
++ChecksSkipped;
|
|
if (!C->getZExtValue())
|
|
return;
|
|
else
|
|
Cmp = nullptr; // unconditional branch
|
|
}
|
|
++ChecksAdded;
|
|
|
|
BasicBlock::iterator Inst = Builder->GetInsertPoint();
|
|
BasicBlock *OldBB = Inst->getParent();
|
|
BasicBlock *Cont = OldBB->splitBasicBlock(Inst);
|
|
OldBB->getTerminator()->eraseFromParent();
|
|
|
|
if (Cmp)
|
|
BranchInst::Create(getTrapBB(), Cont, Cmp, OldBB);
|
|
else
|
|
BranchInst::Create(getTrapBB(), OldBB);
|
|
}
|
|
|
|
|
|
/// instrument - adds run-time bounds checks to memory accessing instructions.
|
|
/// Ptr is the pointer that will be read/written, and InstVal is either the
|
|
/// result from the load or the value being stored. It is used to determine the
|
|
/// size of memory block that is touched.
|
|
/// Returns true if any change was made to the IR, false otherwise.
|
|
bool BoundsChecking::instrument(Value *Ptr, Value *InstVal,
|
|
const DataLayout &DL) {
|
|
uint64_t NeededSize = DL.getTypeStoreSize(InstVal->getType());
|
|
DEBUG(dbgs() << "Instrument " << *Ptr << " for " << Twine(NeededSize)
|
|
<< " bytes\n");
|
|
|
|
SizeOffsetEvalType SizeOffset = ObjSizeEval->compute(Ptr);
|
|
|
|
if (!ObjSizeEval->bothKnown(SizeOffset)) {
|
|
++ChecksUnable;
|
|
return false;
|
|
}
|
|
|
|
Value *Size = SizeOffset.first;
|
|
Value *Offset = SizeOffset.second;
|
|
ConstantInt *SizeCI = dyn_cast<ConstantInt>(Size);
|
|
|
|
Type *IntTy = DL.getIntPtrType(Ptr->getType());
|
|
Value *NeededSizeVal = ConstantInt::get(IntTy, NeededSize);
|
|
|
|
// three checks are required to ensure safety:
|
|
// . Offset >= 0 (since the offset is given from the base ptr)
|
|
// . Size >= Offset (unsigned)
|
|
// . Size - Offset >= NeededSize (unsigned)
|
|
//
|
|
// optimization: if Size >= 0 (signed), skip 1st check
|
|
// FIXME: add NSW/NUW here? -- we dont care if the subtraction overflows
|
|
Value *ObjSize = Builder->CreateSub(Size, Offset);
|
|
Value *Cmp2 = Builder->CreateICmpULT(Size, Offset);
|
|
Value *Cmp3 = Builder->CreateICmpULT(ObjSize, NeededSizeVal);
|
|
Value *Or = Builder->CreateOr(Cmp2, Cmp3);
|
|
if (!SizeCI || SizeCI->getValue().slt(0)) {
|
|
Value *Cmp1 = Builder->CreateICmpSLT(Offset, ConstantInt::get(IntTy, 0));
|
|
Or = Builder->CreateOr(Cmp1, Or);
|
|
}
|
|
emitBranchToTrap(Or);
|
|
|
|
return true;
|
|
}
|
|
|
|
bool BoundsChecking::runOnFunction(Function &F) {
|
|
const DataLayout &DL = F.getParent()->getDataLayout();
|
|
TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
|
|
|
|
TrapBB = nullptr;
|
|
BuilderTy TheBuilder(F.getContext(), TargetFolder(DL));
|
|
Builder = &TheBuilder;
|
|
ObjectSizeOffsetEvaluator TheObjSizeEval(DL, TLI, F.getContext(),
|
|
/*RoundToAlign=*/true);
|
|
ObjSizeEval = &TheObjSizeEval;
|
|
|
|
// check HANDLE_MEMORY_INST in include/llvm/Instruction.def for memory
|
|
// touching instructions
|
|
std::vector<Instruction*> WorkList;
|
|
for (inst_iterator i = inst_begin(F), e = inst_end(F); i != e; ++i) {
|
|
Instruction *I = &*i;
|
|
if (isa<LoadInst>(I) || isa<StoreInst>(I) || isa<AtomicCmpXchgInst>(I) ||
|
|
isa<AtomicRMWInst>(I))
|
|
WorkList.push_back(I);
|
|
}
|
|
|
|
bool MadeChange = false;
|
|
for (Instruction *i : WorkList) {
|
|
Inst = i;
|
|
|
|
Builder->SetInsertPoint(Inst);
|
|
if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
|
|
MadeChange |= instrument(LI->getPointerOperand(), LI, DL);
|
|
} else if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
|
|
MadeChange |=
|
|
instrument(SI->getPointerOperand(), SI->getValueOperand(), DL);
|
|
} else if (AtomicCmpXchgInst *AI = dyn_cast<AtomicCmpXchgInst>(Inst)) {
|
|
MadeChange |=
|
|
instrument(AI->getPointerOperand(), AI->getCompareOperand(), DL);
|
|
} else if (AtomicRMWInst *AI = dyn_cast<AtomicRMWInst>(Inst)) {
|
|
MadeChange |=
|
|
instrument(AI->getPointerOperand(), AI->getValOperand(), DL);
|
|
} else {
|
|
llvm_unreachable("unknown Instruction type");
|
|
}
|
|
}
|
|
return MadeChange;
|
|
}
|
|
|
|
FunctionPass *llvm::createBoundsCheckingPass() {
|
|
return new BoundsChecking();
|
|
}
|