CDSPass.cpp

   1 //===-- CDSPass.cpp - xxx -------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 // This file is distributed under the University of Illinois Open Source
   7 // License. See LICENSE.TXT for details.
   8 //
   9 //===----------------------------------------------------------------------===//
  10 //
  11 // This file is a modified version of ThreadSanitizer.cpp, a part of a race detector.
  12 //
  13 // The tool is under development, for the details about previous versions see
  14 // http://code.google.com/p/data-race-test
  15 //
  16 // The instrumentation phase is quite simple:
  17 //   - Insert calls to run-time library before every memory access.
  18 //      - Optimizations may apply to avoid instrumenting some of the accesses.
  19 //   - Insert calls at function entry/exit.
  20 // The rest is handled by the run-time library.
  21 //===----------------------------------------------------------------------===//
  22
  23 #include "llvm/ADT/Statistic.h"
  24 #include "llvm/ADT/StringExtras.h"
  25 #include "llvm/ADT/SmallString.h"
  26 #include "llvm/Analysis/ValueTracking.h"
  27 #include "llvm/Analysis/CaptureTracking.h"
  28 #include "llvm/IR/BasicBlock.h"
  29 #include "llvm/IR/Function.h"
  30 #include "llvm/IR/IRBuilder.h"
  31 #include "llvm/IR/Instructions.h"
  32 #include "llvm/IR/LLVMContext.h"
  33 #include "llvm/IR/LegacyPassManager.h"
  34 #include "llvm/IR/Module.h"
  35 #include "llvm/IR/PassManager.h"
  36 #include "llvm/Pass.h"
  37 #include "llvm/ProfileData/InstrProf.h"
  38 #include "llvm/Support/raw_ostream.h"
  39 #include "llvm/Support/AtomicOrdering.h"
  40 #include "llvm/Support/Debug.h"
  41 #include "llvm/Transforms/Scalar.h"
  42 #include "llvm/Transforms/Utils/Local.h"
  43 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
  44 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
  45 #include "llvm/Transforms/Utils/EscapeEnumerator.h"
  46 #include <vector>
  47
  48 using namespace llvm;
  49
  50 #define DEBUG_TYPE "CDS"
  51 #include <llvm/IR/DebugLoc.h>
  52
  53 Value *getPosition( Instruction * I, IRBuilder <> IRB, bool print = false)
  54 {
  55         const DebugLoc & debug_location = I->getDebugLoc ();
  56         std::string position_string;
  57         {
  58                 llvm::raw_string_ostream position_stream (position_string);
  59                 debug_location . print (position_stream);
  60         }
  61
  62         if (print) {
  63                 errs() << position_string << "\n";
  64         }
  65
  66         return IRB.CreateGlobalStringPtr (position_string);
  67 }
  68
  69 STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
  70 STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
  71 STATISTIC(NumAccessesWithBadSize, "Number of accesses with bad size");
  72 // STATISTIC(NumInstrumentedVtableWrites, "Number of vtable ptr writes");
  73 // STATISTIC(NumInstrumentedVtableReads, "Number of vtable ptr reads");
  74
  75 STATISTIC(NumOmittedReadsBeforeWrite,
  76           "Number of reads ignored due to following writes");
  77 STATISTIC(NumOmittedReadsFromConstantGlobals,
  78           "Number of reads from constant globals");
  79 STATISTIC(NumOmittedReadsFromVtable, "Number of vtable reads");
  80 STATISTIC(NumOmittedNonCaptured, "Number of accesses ignored due to capturing");
  81
  82 Type * OrdTy;
  83
  84 Type * Int8PtrTy;
  85 Type * Int16PtrTy;
  86 Type * Int32PtrTy;
  87 Type * Int64PtrTy;
  88
  89 Type * VoidTy;
  90
  91 static const size_t kNumberOfAccessSizes = 4;
  92
  93 int getAtomicOrderIndex(AtomicOrdering order){
  94         switch (order) {
  95                 case AtomicOrdering::Monotonic:
  96                         return (int)AtomicOrderingCABI::relaxed;
  97                 //  case AtomicOrdering::Consume:         // not specified yet
  98                 //    return AtomicOrderingCABI::consume;
  99                 case AtomicOrdering::Acquire:
 100                         return (int)AtomicOrderingCABI::acquire;
 101                 case AtomicOrdering::Release:
 102                         return (int)AtomicOrderingCABI::release;
 103                 case AtomicOrdering::AcquireRelease:
 104                         return (int)AtomicOrderingCABI::acq_rel;
 105                 case AtomicOrdering::SequentiallyConsistent:
 106                         return (int)AtomicOrderingCABI::seq_cst;
 107                 default:
 108                         // unordered or Not Atomic
 109                         return -1;
 110         }
 111 }
 112
 113 namespace {
 114         struct CDSPass : public FunctionPass {
 115                 static char ID;
 116                 CDSPass() : FunctionPass(ID) {}
 117                 bool runOnFunction(Function &F) override;
 118
 119         private:
 120                 void initializeCallbacks(Module &M);
 121                 bool instrumentLoadOrStore(Instruction *I, const DataLayout &DL);
 122                 bool instrumentVolatile(Instruction *I, const DataLayout &DL);
 123                 bool isAtomicCall(Instruction *I);
 124                 bool instrumentAtomic(Instruction *I, const DataLayout &DL);
 125                 bool instrumentAtomicCall(CallInst *CI, const DataLayout &DL);
 126                 void chooseInstructionsToInstrument(SmallVectorImpl<Instruction *> &Local,
 127                                                                                         SmallVectorImpl<Instruction *> &All,
 128                                                                                         const DataLayout &DL);
 129                 bool addrPointsToConstantData(Value *Addr);
 130                 int getMemoryAccessFuncIndex(Value *Addr, const DataLayout &DL);
 131
 132                 // Callbacks to run-time library are computed in doInitialization.
 133                 Constant * CDSFuncEntry;
 134                 Constant * CDSFuncExit;
 135
 136                 Constant * CDSLoad[kNumberOfAccessSizes];
 137                 Constant * CDSStore[kNumberOfAccessSizes];
 138                 Constant * CDSVolatileLoad[kNumberOfAccessSizes];
 139                 Constant * CDSVolatileStore[kNumberOfAccessSizes];
 140                 Constant * CDSAtomicInit[kNumberOfAccessSizes];
 141                 Constant * CDSAtomicLoad[kNumberOfAccessSizes];
 142                 Constant * CDSAtomicStore[kNumberOfAccessSizes];
 143                 Constant * CDSAtomicRMW[AtomicRMWInst::LAST_BINOP + 1][kNumberOfAccessSizes];
 144                 Constant * CDSAtomicCAS_V1[kNumberOfAccessSizes];
 145                 Constant * CDSAtomicCAS_V2[kNumberOfAccessSizes];
 146                 Constant * CDSAtomicThreadFence;
 147
 148                 std::vector<StringRef> AtomicFuncNames;
 149                 std::vector<StringRef> PartialAtomicFuncNames;
 150         };
 151 }
 152
 153 static bool isVtableAccess(Instruction *I) {
 154         if (MDNode *Tag = I->getMetadata(LLVMContext::MD_tbaa))
 155                 return Tag->isTBAAVtableAccess();
 156         return false;
 157 }
 158
 159 void CDSPass::initializeCallbacks(Module &M) {
 160         LLVMContext &Ctx = M.getContext();
 161
 162         Type * Int1Ty = Type::getInt1Ty(Ctx);
 163         OrdTy = Type::getInt32Ty(Ctx);
 164
 165         Int8PtrTy  = Type::getInt8PtrTy(Ctx);
 166         Int16PtrTy = Type::getInt16PtrTy(Ctx);
 167         Int32PtrTy = Type::getInt32PtrTy(Ctx);
 168         Int64PtrTy = Type::getInt64PtrTy(Ctx);
 169
 170         VoidTy = Type::getVoidTy(Ctx);
 171
 172         CDSFuncEntry = M.getOrInsertFunction("cds_func_entry",
 173                                                                 VoidTy, Int8PtrTy);
 174         CDSFuncExit = M.getOrInsertFunction("cds_func_exit",
 175                                                                 VoidTy, Int8PtrTy);
 176
 177         // Get the function to call from our untime library.
 178         for (unsigned i = 0; i < kNumberOfAccessSizes; i++) {
 179                 const unsigned ByteSize = 1U << i;
 180                 const unsigned BitSize = ByteSize * 8;
 181
 182                 std::string ByteSizeStr = utostr(ByteSize);
 183                 std::string BitSizeStr = utostr(BitSize);
 184
 185                 Type *Ty = Type::getIntNTy(Ctx, BitSize);
 186                 Type *PtrTy = Ty->getPointerTo();
 187
 188                 // uint8_t cds_atomic_load8 (void * obj, int atomic_index)
 189                 // void cds_atomic_store8 (void * obj, int atomic_index, uint8_t val)
 190                 SmallString<32> LoadName("cds_load" + BitSizeStr);
 191                 SmallString<32> StoreName("cds_store" + BitSizeStr);
 192                 SmallString<32> VolatileLoadName("cds_volatile_load" + BitSizeStr);
 193                 SmallString<32> VolatileStoreName("cds_volatile_store" + BitSizeStr);
 194                 SmallString<32> AtomicInitName("cds_atomic_init" + BitSizeStr);
 195                 SmallString<32> AtomicLoadName("cds_atomic_load" + BitSizeStr);
 196                 SmallString<32> AtomicStoreName("cds_atomic_store" + BitSizeStr);
 197
 198                 CDSLoad[i]  = M.getOrInsertFunction(LoadName, VoidTy, PtrTy);
 199                 CDSStore[i] = M.getOrInsertFunction(StoreName, VoidTy, PtrTy);
 200                 CDSVolatileLoad[i]  = M.getOrInsertFunction(VolatileLoadName,
 201                                                                         Ty, PtrTy, Int8PtrTy);
 202                 CDSVolatileStore[i] = M.getOrInsertFunction(VolatileStoreName,
 203                                                                         VoidTy, PtrTy, Ty, Int8PtrTy);
 204                 CDSAtomicInit[i] = M.getOrInsertFunction(AtomicInitName,
 205                                                                 VoidTy, PtrTy, Ty, Int8PtrTy);
 206                 CDSAtomicLoad[i]  = M.getOrInsertFunction(AtomicLoadName,
 207                                                                 Ty, PtrTy, OrdTy, Int8PtrTy);
 208                 CDSAtomicStore[i] = M.getOrInsertFunction(AtomicStoreName,
 209                                                                 VoidTy, PtrTy, Ty, OrdTy, Int8PtrTy);
 210
 211                 for (int op = AtomicRMWInst::FIRST_BINOP;
 212                         op <= AtomicRMWInst::LAST_BINOP; ++op) {
 213                         CDSAtomicRMW[op][i] = nullptr;
 214                         std::string NamePart;
 215
 216                         if (op == AtomicRMWInst::Xchg)
 217                                 NamePart = "_exchange";
 218                         else if (op == AtomicRMWInst::Add)
 219                                 NamePart = "_fetch_add";
 220                         else if (op == AtomicRMWInst::Sub)
 221                                 NamePart = "_fetch_sub";
 222                         else if (op == AtomicRMWInst::And)
 223                                 NamePart = "_fetch_and";
 224                         else if (op == AtomicRMWInst::Or)
 225                                 NamePart = "_fetch_or";
 226                         else if (op == AtomicRMWInst::Xor)
 227                                 NamePart = "_fetch_xor";
 228                         else
 229                                 continue;
 230
 231                         SmallString<32> AtomicRMWName("cds_atomic" + NamePart + BitSizeStr);
 232                         CDSAtomicRMW[op][i] = M.getOrInsertFunction(AtomicRMWName,
 233                                                                                 Ty, PtrTy, Ty, OrdTy, Int8PtrTy);
 234                 }
 235
 236                 // only supportes strong version
 237                 SmallString<32> AtomicCASName_V1("cds_atomic_compare_exchange" + BitSizeStr + "_v1");
 238                 SmallString<32> AtomicCASName_V2("cds_atomic_compare_exchange" + BitSizeStr + "_v2");
 239                 CDSAtomicCAS_V1[i] = M.getOrInsertFunction(AtomicCASName_V1,
 240                                                                 Ty, PtrTy, Ty, Ty, OrdTy, OrdTy, Int8PtrTy);
 241                 CDSAtomicCAS_V2[i] = M.getOrInsertFunction(AtomicCASName_V2,
 242                                                                 Int1Ty, PtrTy, PtrTy, Ty, OrdTy, OrdTy, Int8PtrTy);
 243         }
 244
 245         CDSAtomicThreadFence = M.getOrInsertFunction("cds_atomic_thread_fence",
 246                                                                                                         VoidTy, OrdTy, Int8PtrTy);
 247 }
 248
 249 static bool shouldInstrumentReadWriteFromAddress(const Module *M, Value *Addr) {
 250         // Peel off GEPs and BitCasts.
 251         Addr = Addr->stripInBoundsOffsets();
 252
 253         if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Addr)) {
 254                 if (GV->hasSection()) {
 255                         StringRef SectionName = GV->getSection();
 256                         // Check if the global is in the PGO counters section.
 257                         auto OF = Triple(M->getTargetTriple()).getObjectFormat();
 258                         if (SectionName.endswith(
 259                               getInstrProfSectionName(IPSK_cnts, OF, /*AddSegmentInfo=*/false)))
 260                                 return false;
 261                 }
 262
 263                 // Check if the global is private gcov data.
 264                 if (GV->getName().startswith("__llvm_gcov") ||
 265                 GV->getName().startswith("__llvm_gcda"))
 266                 return false;
 267         }
 268
 269         // Do not instrument acesses from different address spaces; we cannot deal
 270         // with them.
 271         if (Addr) {
 272                 Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
 273                 if (PtrTy->getPointerAddressSpace() != 0)
 274                         return false;
 275         }
 276
 277         return true;
 278 }
 279
 280 bool CDSPass::addrPointsToConstantData(Value *Addr) {
 281         // If this is a GEP, just analyze its pointer operand.
 282         if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Addr))
 283                 Addr = GEP->getPointerOperand();
 284
 285         if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Addr)) {
 286                 if (GV->isConstant()) {
 287                         // Reads from constant globals can not race with any writes.
 288                         NumOmittedReadsFromConstantGlobals++;
 289                         return true;
 290                 }
 291         } else if (LoadInst *L = dyn_cast<LoadInst>(Addr)) {
 292                 if (isVtableAccess(L)) {
 293                         // Reads from a vtable pointer can not race with any writes.
 294                         NumOmittedReadsFromVtable++;
 295                         return true;
 296                 }
 297         }
 298         return false;
 299 }
 300
 301 bool CDSPass::runOnFunction(Function &F) {
 302         if (F.getName() == "main") {
 303                 F.setName("user_main");
 304                 errs() << "main replaced by user_main\n";
 305         }
 306
 307         if (true) {
 308                 initializeCallbacks( *F.getParent() );
 309
 310                 AtomicFuncNames =
 311                 {
 312                         "atomic_init", "atomic_load", "atomic_store",
 313                         "atomic_fetch_", "atomic_exchange", "atomic_compare_exchange_"
 314                 };
 315
 316                 PartialAtomicFuncNames =
 317                 {
 318                         "load", "store", "fetch", "exchange", "compare_exchange_"
 319                 };
 320
 321                 SmallVector<Instruction*, 8> AllLoadsAndStores;
 322                 SmallVector<Instruction*, 8> LocalLoadsAndStores;
 323                 SmallVector<Instruction*, 8> VolatileLoadsAndStores;
 324                 SmallVector<Instruction*, 8> AtomicAccesses;
 325
 326                 std::vector<Instruction *> worklist;
 327
 328                 bool Res = false;
 329                 bool HasAtomic = false;
 330                 bool HasVolatile = false;
 331                 const DataLayout &DL = F.getParent()->getDataLayout();
 332
 333                 // errs() << "--- " << F.getName() << "---\n";
 334
 335                 for (auto &B : F) {
 336                         for (auto &I : B) {
 337                                 if ( (&I)->isAtomic() || isAtomicCall(&I) ) {
 338                                         AtomicAccesses.push_back(&I);
 339                                         HasAtomic = true;
 340                                 } else if (isa<LoadInst>(I) || isa<StoreInst>(I)) {
 341                                         LoadInst *LI = dyn_cast<LoadInst>(&I);
 342                                         StoreInst *SI = dyn_cast<StoreInst>(&I);
 343                                         bool isVolatile = ( LI ? LI->isVolatile() : SI->isVolatile() );
 344
 345                                         if (isVolatile) {
 346                                                 VolatileLoadsAndStores.push_back(&I);
 347                                                 HasVolatile = true;
 348                                         } else
 349                                                 LocalLoadsAndStores.push_back(&I);
 350                                 } else if (isa<CallInst>(I) || isa<InvokeInst>(I)) {
 351                                         // not implemented yet
 352                                 }
 353                         }
 354
 355                         chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores, DL);
 356                 }
 357
 358                 for (auto Inst : AllLoadsAndStores) {
 359                         Res |= instrumentLoadOrStore(Inst, DL);
 360                 }
 361
 362                 for (auto Inst : VolatileLoadsAndStores) {
 363                         Res |= instrumentVolatile(Inst, DL);
 364                 }
 365
 366                 for (auto Inst : AtomicAccesses) {
 367                         Res |= instrumentAtomic(Inst, DL);
 368                 }
 369
 370                 // only instrument functions that contain atomics
 371                 if (Res && ( HasAtomic || HasVolatile) ) {
 372                         IRBuilder<> IRB(F.getEntryBlock().getFirstNonPHI());
 373                         /* Unused for now
 374                         Value *ReturnAddress = IRB.CreateCall(
 375                                 Intrinsic::getDeclaration(F.getParent(), Intrinsic::returnaddress),
 376                                 IRB.getInt32(0));
 377                         */
 378
 379                         Value * FuncName = IRB.CreateGlobalStringPtr(F.getName());
 380                         IRB.CreateCall(CDSFuncEntry, FuncName);
 381
 382                         EscapeEnumerator EE(F, "cds_cleanup", true);
 383                         while (IRBuilder<> *AtExit = EE.Next()) {
 384                           AtExit->CreateCall(CDSFuncExit, FuncName);
 385                         }
 386
 387                         Res = true;
 388                 }
 389         }
 390
 391         return false;
 392 }
 393
 394 void CDSPass::chooseInstructionsToInstrument(
 395         SmallVectorImpl<Instruction *> &Local, SmallVectorImpl<Instruction *> &All,
 396         const DataLayout &DL) {
 397         SmallPtrSet<Value*, 8> WriteTargets;
 398         // Iterate from the end.
 399         for (Instruction *I : reverse(Local)) {
 400                 if (StoreInst *Store = dyn_cast<StoreInst>(I)) {
 401                         Value *Addr = Store->getPointerOperand();
 402                         if (!shouldInstrumentReadWriteFromAddress(I->getModule(), Addr))
 403                                 continue;
 404                         WriteTargets.insert(Addr);
 405                 } else {
 406                         LoadInst *Load = cast<LoadInst>(I);
 407                         Value *Addr = Load->getPointerOperand();
 408                         if (!shouldInstrumentReadWriteFromAddress(I->getModule(), Addr))
 409                                 continue;
 410                         if (WriteTargets.count(Addr)) {
 411                                 // We will write to this temp, so no reason to analyze the read.
 412                                 NumOmittedReadsBeforeWrite++;
 413                                 continue;
 414                         }
 415                         if (addrPointsToConstantData(Addr)) {
 416                                 // Addr points to some constant data -- it can not race with any writes.
 417                                 continue;
 418                         }
 419                 }
 420                 Value *Addr = isa<StoreInst>(*I)
 421                         ? cast<StoreInst>(I)->getPointerOperand()
 422                         : cast<LoadInst>(I)->getPointerOperand();
 423                 if (isa<AllocaInst>(GetUnderlyingObject(Addr, DL)) &&
 424                                 !PointerMayBeCaptured(Addr, true, true)) {
 425                         // The variable is addressable but not captured, so it cannot be
 426                         // referenced from a different thread and participate in a data race
 427                         // (see llvm/Analysis/CaptureTracking.h for details).
 428                         NumOmittedNonCaptured++;
 429                         continue;
 430                 }
 431                 All.push_back(I);
 432         }
 433         Local.clear();
 434 }
 435
 436
 437 bool CDSPass::instrumentLoadOrStore(Instruction *I,
 438                                                                         const DataLayout &DL) {
 439         IRBuilder<> IRB(I);
 440         bool IsWrite = isa<StoreInst>(*I);
 441         Value *Addr = IsWrite
 442                 ? cast<StoreInst>(I)->getPointerOperand()
 443                 : cast<LoadInst>(I)->getPointerOperand();
 444
 445         // swifterror memory addresses are mem2reg promoted by instruction selection.
 446         // As such they cannot have regular uses like an instrumentation function and
 447         // it makes no sense to track them as memory.
 448         if (Addr->isSwiftError())
 449         return false;
 450
 451         int Idx = getMemoryAccessFuncIndex(Addr, DL);
 452         if (Idx < 0)
 453                 return false;
 454
 455 //  not supported by CDS yet
 456 /*  if (IsWrite && isVtableAccess(I)) {
 457     LLVM_DEBUG(dbgs() << "  VPTR : " << *I << "\n");
 458     Value *StoredValue = cast<StoreInst>(I)->getValueOperand();
 459     // StoredValue may be a vector type if we are storing several vptrs at once.
 460     // In this case, just take the first element of the vector since this is
 461     // enough to find vptr races.
 462     if (isa<VectorType>(StoredValue->getType()))
 463       StoredValue = IRB.CreateExtractElement(
 464           StoredValue, ConstantInt::get(IRB.getInt32Ty(), 0));
 465     if (StoredValue->getType()->isIntegerTy())
 466       StoredValue = IRB.CreateIntToPtr(StoredValue, IRB.getInt8PtrTy());
 467     // Call TsanVptrUpdate.
 468     IRB.CreateCall(TsanVptrUpdate,
 469                    {IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),
 470                     IRB.CreatePointerCast(StoredValue, IRB.getInt8PtrTy())});
 471     NumInstrumentedVtableWrites++;
 472     return true;
 473   }
 474
 475   if (!IsWrite && isVtableAccess(I)) {
 476     IRB.CreateCall(TsanVptrLoad,
 477                    IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()));
 478     NumInstrumentedVtableReads++;
 479     return true;
 480   }
 481 */
 482
 483         Value *OnAccessFunc = nullptr;
 484         OnAccessFunc = IsWrite ? CDSStore[Idx] : CDSLoad[Idx];
 485
 486         Type *ArgType = IRB.CreatePointerCast(Addr, Addr->getType())->getType();
 487
 488         if ( ArgType != Int8PtrTy && ArgType != Int16PtrTy &&
 489                         ArgType != Int32PtrTy && ArgType != Int64PtrTy ) {
 490                 // if other types of load or stores are passed in
 491                 return false;
 492         }
 493         IRB.CreateCall(OnAccessFunc, IRB.CreatePointerCast(Addr, Addr->getType()));
 494         if (IsWrite) NumInstrumentedWrites++;
 495         else         NumInstrumentedReads++;
 496         return true;
 497 }
 498
 499 bool CDSPass::instrumentVolatile(Instruction * I, const DataLayout &DL) {
 500         IRBuilder<> IRB(I);
 501         Value *position = getPosition(I, IRB);
 502
 503         if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
 504                 assert( LI->isVolatile() );
 505                 Value *Addr = LI->getPointerOperand();
 506                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 507                 if (Idx < 0)
 508                         return false;
 509
 510                 Value *args[] = {Addr, position};
 511                 Instruction* funcInst=CallInst::Create(CDSVolatileLoad[Idx], args);
 512                 ReplaceInstWithInst(LI, funcInst);
 513         } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
 514                 assert( SI->isVolatile() );
 515                 Value *Addr = SI->getPointerOperand();
 516                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 517                 if (Idx < 0)
 518                         return false;
 519
 520                 Value *val = SI->getValueOperand();
 521                 Value *args[] = {Addr, val, position};
 522                 Instruction* funcInst=CallInst::Create(CDSVolatileStore[Idx], args);
 523                 ReplaceInstWithInst(SI, funcInst);
 524         } else {
 525                 return false;
 526         }
 527
 528         return true;
 529 }
 530
 531 bool CDSPass::instrumentAtomic(Instruction * I, const DataLayout &DL) {
 532         IRBuilder<> IRB(I);
 533
 534         if (auto *CI = dyn_cast<CallInst>(I)) {
 535                 return instrumentAtomicCall(CI, DL);
 536         }
 537
 538         Value *position = getPosition(I, IRB);
 539
 540         if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
 541                 Value *Addr = LI->getPointerOperand();
 542                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 543                 if (Idx < 0)
 544                         return false;
 545
 546                 int atomic_order_index = getAtomicOrderIndex(LI->getOrdering());
 547                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 548                 Value *args[] = {Addr, order, position};
 549                 Instruction* funcInst=CallInst::Create(CDSAtomicLoad[Idx], args);
 550                 ReplaceInstWithInst(LI, funcInst);
 551         } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
 552                 Value *Addr = SI->getPointerOperand();
 553                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 554                 if (Idx < 0)
 555                         return false;
 556
 557                 int atomic_order_index = getAtomicOrderIndex(SI->getOrdering());
 558                 Value *val = SI->getValueOperand();
 559                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 560                 Value *args[] = {Addr, val, order, position};
 561                 Instruction* funcInst=CallInst::Create(CDSAtomicStore[Idx], args);
 562                 ReplaceInstWithInst(SI, funcInst);
 563         } else if (AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I)) {
 564                 Value *Addr = RMWI->getPointerOperand();
 565                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 566                 if (Idx < 0)
 567                         return false;
 568
 569                 int atomic_order_index = getAtomicOrderIndex(RMWI->getOrdering());
 570                 Value *val = RMWI->getValOperand();
 571                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 572                 Value *args[] = {Addr, val, order, position};
 573                 Instruction* funcInst = CallInst::Create(CDSAtomicRMW[RMWI->getOperation()][Idx], args);
 574                 ReplaceInstWithInst(RMWI, funcInst);
 575         } else if (AtomicCmpXchgInst *CASI = dyn_cast<AtomicCmpXchgInst>(I)) {
 576                 IRBuilder<> IRB(CASI);
 577
 578                 Value *Addr = CASI->getPointerOperand();
 579                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 580                 if (Idx < 0)
 581                         return false;
 582
 583                 const unsigned ByteSize = 1U << Idx;
 584                 const unsigned BitSize = ByteSize * 8;
 585                 Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
 586                 Type *PtrTy = Ty->getPointerTo();
 587
 588                 Value *CmpOperand = IRB.CreateBitOrPointerCast(CASI->getCompareOperand(), Ty);
 589                 Value *NewOperand = IRB.CreateBitOrPointerCast(CASI->getNewValOperand(), Ty);
 590
 591                 int atomic_order_index_succ = getAtomicOrderIndex(CASI->getSuccessOrdering());
 592                 int atomic_order_index_fail = getAtomicOrderIndex(CASI->getFailureOrdering());
 593                 Value *order_succ = ConstantInt::get(OrdTy, atomic_order_index_succ);
 594                 Value *order_fail = ConstantInt::get(OrdTy, atomic_order_index_fail);
 595
 596                 Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
 597                                                  CmpOperand, NewOperand,
 598                                                  order_succ, order_fail, position};
 599
 600                 CallInst *funcInst = IRB.CreateCall(CDSAtomicCAS_V1[Idx], Args);
 601                 Value *Success = IRB.CreateICmpEQ(funcInst, CmpOperand);
 602
 603                 Value *OldVal = funcInst;
 604                 Type *OrigOldValTy = CASI->getNewValOperand()->getType();
 605                 if (Ty != OrigOldValTy) {
 606                         // The value is a pointer, so we need to cast the return value.
 607                         OldVal = IRB.CreateIntToPtr(funcInst, OrigOldValTy);
 608                 }
 609
 610                 Value *Res =
 611                   IRB.CreateInsertValue(UndefValue::get(CASI->getType()), OldVal, 0);
 612                 Res = IRB.CreateInsertValue(Res, Success, 1);
 613
 614                 I->replaceAllUsesWith(Res);
 615                 I->eraseFromParent();
 616         } else if (FenceInst *FI = dyn_cast<FenceInst>(I)) {
 617                 int atomic_order_index = getAtomicOrderIndex(FI->getOrdering());
 618                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 619                 Value *Args[] = {order, position};
 620
 621                 CallInst *funcInst = CallInst::Create(CDSAtomicThreadFence, Args);
 622                 ReplaceInstWithInst(FI, funcInst);
 623                 // errs() << "Thread Fences replaced\n";
 624         }
 625         return true;
 626 }
 627
 628 bool CDSPass::isAtomicCall(Instruction *I) {
 629         if ( auto *CI = dyn_cast<CallInst>(I) ) {
 630                 Function *fun = CI->getCalledFunction();
 631                 if (fun == NULL)
 632                         return false;
 633
 634                 StringRef funName = fun->getName();
 635
 636                 // todo: come up with better rules for function name checking
 637                 for (StringRef name : AtomicFuncNames) {
 638                         if ( funName.contains(name) )
 639                                 return true;
 640                 }
 641
 642                 for (StringRef PartialName : PartialAtomicFuncNames) {
 643                         if (funName.contains(PartialName) &&
 644                                         funName.contains("atomic") )
 645                                 return true;
 646                 }
 647         }
 648
 649         return false;
 650 }
 651
 652 bool CDSPass::instrumentAtomicCall(CallInst *CI, const DataLayout &DL) {
 653         IRBuilder<> IRB(CI);
 654         Function *fun = CI->getCalledFunction();
 655         StringRef funName = fun->getName();
 656         std::vector<Value *> parameters;
 657
 658         User::op_iterator begin = CI->arg_begin();
 659         User::op_iterator end = CI->arg_end();
 660         for (User::op_iterator it = begin; it != end; ++it) {
 661                 Value *param = *it;
 662                 parameters.push_back(param);
 663         }
 664
 665         // obtain source line number of the CallInst
 666         Value *position = getPosition(CI, IRB);
 667
 668         // the pointer to the address is always the first argument
 669         Value *OrigPtr = parameters[0];
 670
 671         int Idx = getMemoryAccessFuncIndex(OrigPtr, DL);
 672         if (Idx < 0)
 673                 return false;
 674
 675         const unsigned ByteSize = 1U << Idx;
 676         const unsigned BitSize = ByteSize * 8;
 677         Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
 678         Type *PtrTy = Ty->getPointerTo();
 679
 680         // atomic_init; args = {obj, order}
 681         if (funName.contains("atomic_init")) {
 682                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 683                 Value *val = IRB.CreateBitOrPointerCast(parameters[1], Ty);
 684                 Value *args[] = {ptr, val, position};
 685
 686                 Instruction* funcInst = CallInst::Create(CDSAtomicInit[Idx], args);
 687                 ReplaceInstWithInst(CI, funcInst);
 688
 689                 return true;
 690         }
 691
 692         // atomic_load; args = {obj, order}
 693         if (funName.contains("atomic_load")) {
 694                 bool isExplicit = funName.contains("atomic_load_explicit");
 695
 696                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 697                 Value *order;
 698                 if (isExplicit)
 699                         order = IRB.CreateBitOrPointerCast(parameters[1], OrdTy);
 700                 else
 701                         order = ConstantInt::get(OrdTy,
 702                                                         (int) AtomicOrderingCABI::seq_cst);
 703                 Value *args[] = {ptr, order, position};
 704
 705                 Instruction* funcInst = CallInst::Create(CDSAtomicLoad[Idx], args);
 706                 ReplaceInstWithInst(CI, funcInst);
 707
 708                 return true;
 709         } else if (funName.contains("atomic") &&
 710                                         funName.contains("load") ) {
 711                 // does this version of call always have an atomic order as an argument?
 712                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 713                 Value *order = IRB.CreateBitOrPointerCast(parameters[1], OrdTy);
 714                 Value *args[] = {ptr, order, position};
 715
 716                 if (!CI->getType()->isPointerTy()) {
 717                         return false;
 718                 }
 719
 720                 CallInst *funcInst = IRB.CreateCall(CDSAtomicLoad[Idx], args);
 721                 Value *RetVal = IRB.CreateIntToPtr(funcInst, CI->getType());
 722
 723                 CI->replaceAllUsesWith(RetVal);
 724                 CI->eraseFromParent();
 725
 726                 return true;
 727         }
 728
 729         // atomic_store; args = {obj, val, order}
 730         if (funName.contains("atomic_store")) {
 731                 bool isExplicit = funName.contains("atomic_store_explicit");
 732                 Value *OrigVal = parameters[1];
 733
 734                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 735                 Value *val = IRB.CreatePointerCast(OrigVal, Ty);
 736                 Value *order;
 737                 if (isExplicit)
 738                         order = IRB.CreateBitOrPointerCast(parameters[2], OrdTy);
 739                 else
 740                         order = ConstantInt::get(OrdTy,
 741                                                         (int) AtomicOrderingCABI::seq_cst);
 742                 Value *args[] = {ptr, val, order, position};
 743
 744                 Instruction* funcInst = CallInst::Create(CDSAtomicStore[Idx], args);
 745                 ReplaceInstWithInst(CI, funcInst);
 746
 747                 return true;
 748         } else if (funName.contains("atomic") &&
 749                                         funName.contains("store") ) {
 750                 // does this version of call always have an atomic order as an argument?
 751                 Value *OrigVal = parameters[1];
 752
 753                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 754                 Value *val = IRB.CreatePointerCast(OrigVal, Ty);
 755                 Value *order = IRB.CreateBitOrPointerCast(parameters[2], OrdTy);
 756                 Value *args[] = {ptr, val, order, position};
 757
 758                 Instruction* funcInst = CallInst::Create(CDSAtomicStore[Idx], args);
 759                 ReplaceInstWithInst(CI, funcInst);
 760
 761                 return true;
 762         }
 763
 764         // atomic_fetch_*; args = {obj, val, order}
 765         if (funName.contains("atomic_fetch_") ||
 766                         funName.contains("atomic_exchange") ) {
 767                 bool isExplicit = funName.contains("_explicit");
 768                 Value *OrigVal = parameters[1];
 769
 770                 int op;
 771                 if ( funName.contains("_fetch_add") )
 772                         op = AtomicRMWInst::Add;
 773                 else if ( funName.contains("_fetch_sub") )
 774                         op = AtomicRMWInst::Sub;
 775                 else if ( funName.contains("_fetch_and") )
 776                         op = AtomicRMWInst::And;
 777                 else if ( funName.contains("_fetch_or") )
 778                         op = AtomicRMWInst::Or;
 779                 else if ( funName.contains("_fetch_xor") )
 780                         op = AtomicRMWInst::Xor;
 781                 else if ( funName.contains("atomic_exchange") )
 782                         op = AtomicRMWInst::Xchg;
 783                 else {
 784                         errs() << "Unknown atomic read-modify-write operation\n";
 785                         return false;
 786                 }
 787
 788                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 789                 Value *val = IRB.CreatePointerCast(OrigVal, Ty);
 790                 Value *order;
 791                 if (isExplicit)
 792                         order = IRB.CreateBitOrPointerCast(parameters[2], OrdTy);
 793                 else
 794                         order = ConstantInt::get(OrdTy,
 795                                                         (int) AtomicOrderingCABI::seq_cst);
 796                 Value *args[] = {ptr, val, order, position};
 797
 798                 Instruction* funcInst = CallInst::Create(CDSAtomicRMW[op][Idx], args);
 799                 ReplaceInstWithInst(CI, funcInst);
 800
 801                 return true;
 802         } else if (funName.contains("fetch")) {
 803                 errs() << "atomic exchange captured. Not implemented yet. ";
 804                 errs() << "See source file :";
 805                 getPosition(CI, IRB, true);
 806         } else if (funName.contains("exchange") &&
 807                         !funName.contains("compare_exchange") ) {
 808                 errs() << "atomic exchange captured. Not implemented yet. ";
 809                 errs() << "See source file :";
 810                 getPosition(CI, IRB, true);
 811         }
 812
 813         /* atomic_compare_exchange_*;
 814            args = {obj, expected, new value, order1, order2}
 815         */
 816         if ( funName.contains("atomic_compare_exchange_") ) {
 817                 bool isExplicit = funName.contains("_explicit");
 818
 819                 Value *Addr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 820                 Value *CmpOperand = IRB.CreatePointerCast(parameters[1], PtrTy);
 821                 Value *NewOperand = IRB.CreateBitOrPointerCast(parameters[2], Ty);
 822
 823                 Value *order_succ, *order_fail;
 824                 if (isExplicit) {
 825                         order_succ = IRB.CreateBitOrPointerCast(parameters[3], OrdTy);
 826                         order_fail = IRB.CreateBitOrPointerCast(parameters[4], OrdTy);
 827                 } else  {
 828                         order_succ = ConstantInt::get(OrdTy,
 829                                                         (int) AtomicOrderingCABI::seq_cst);
 830                         order_fail = ConstantInt::get(OrdTy,
 831                                                         (int) AtomicOrderingCABI::seq_cst);
 832                 }
 833
 834                 Value *args[] = {Addr, CmpOperand, NewOperand,
 835                                                         order_succ, order_fail, position};
 836
 837                 Instruction* funcInst = CallInst::Create(CDSAtomicCAS_V2[Idx], args);
 838                 ReplaceInstWithInst(CI, funcInst);
 839
 840                 return true;
 841         } else if ( funName.contains("compare_exchange_strong") ||
 842                                 funName.contains("compare_exchange_weak") ) {
 843                 Value *Addr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 844                 Value *CmpOperand = IRB.CreatePointerCast(parameters[1], PtrTy);
 845                 Value *NewOperand = IRB.CreateBitOrPointerCast(parameters[2], Ty);
 846
 847                 Value *order_succ, *order_fail;
 848                 order_succ = IRB.CreateBitOrPointerCast(parameters[3], OrdTy);
 849                 order_fail = IRB.CreateBitOrPointerCast(parameters[4], OrdTy);
 850
 851                 Value *args[] = {Addr, CmpOperand, NewOperand,
 852                                                         order_succ, order_fail, position};
 853                 Instruction* funcInst = CallInst::Create(CDSAtomicCAS_V2[Idx], args);
 854                 ReplaceInstWithInst(CI, funcInst);
 855
 856                 return true;
 857         }
 858
 859         return false;
 860 }
 861
 862 int CDSPass::getMemoryAccessFuncIndex(Value *Addr,
 863                                                                                 const DataLayout &DL) {
 864         Type *OrigPtrTy = Addr->getType();
 865         Type *OrigTy = cast<PointerType>(OrigPtrTy)->getElementType();
 866         assert(OrigTy->isSized());
 867         uint32_t TypeSize = DL.getTypeStoreSizeInBits(OrigTy);
 868         if (TypeSize != 8  && TypeSize != 16 &&
 869                 TypeSize != 32 && TypeSize != 64 && TypeSize != 128) {
 870                 NumAccessesWithBadSize++;
 871                 // Ignore all unusual sizes.
 872                 return -1;
 873         }
 874         size_t Idx = countTrailingZeros(TypeSize / 8);
 875         //assert(Idx < kNumberOfAccessSizes);
 876         if (Idx >= kNumberOfAccessSizes) {
 877                 return -1;
 878         }
 879         return Idx;
 880 }
 881
 882
 883 char CDSPass::ID = 0;
 884
 885 // Automatically enable the pass.
 886 static void registerCDSPass(const PassManagerBuilder &,
 887                                                         legacy::PassManagerBase &PM) {
 888         PM.add(new CDSPass());
 889 }
 890
 891 /* Enable the pass when opt level is greater than 0 */
 892 static RegisterStandardPasses
 893         RegisterMyPass1(PassManagerBuilder::EP_OptimizerLast,
 894 registerCDSPass);
 895
 896 /* Enable the pass when opt level is 0 */
 897 static RegisterStandardPasses
 898         RegisterMyPass2(PassManagerBuilder::EP_EnabledOnOptLevel0,
 899 registerCDSPass);