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AddressSanitizer.cpp
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1 //===-- AddressSanitizer.cpp - memory error detector ------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of AddressSanitizer, an address sanity checker.
11 // Details of the algorithm:
12 // http://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #define DEBUG_TYPE "asan"
17 
19 #include "llvm/ADT/ArrayRef.h"
20 #include "llvm/ADT/DenseMap.h"
22 #include "llvm/ADT/OwningPtr.h"
23 #include "llvm/ADT/SmallSet.h"
24 #include "llvm/ADT/SmallString.h"
25 #include "llvm/ADT/SmallVector.h"
26 #include "llvm/ADT/Statistic.h"
27 #include "llvm/ADT/StringExtras.h"
28 #include "llvm/ADT/Triple.h"
29 #include "llvm/DIBuilder.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/Function.h"
32 #include "llvm/IR/IRBuilder.h"
33 #include "llvm/IR/InlineAsm.h"
34 #include "llvm/IR/IntrinsicInst.h"
35 #include "llvm/IR/LLVMContext.h"
36 #include "llvm/IR/Module.h"
37 #include "llvm/IR/Type.h"
38 #include "llvm/InstVisitor.h"
39 #include "llvm/Support/CallSite.h"
41 #include "llvm/Support/DataTypes.h"
42 #include "llvm/Support/Debug.h"
43 #include "llvm/Support/Endian.h"
51 #include <algorithm>
52 #include <string>
53 
54 using namespace llvm;
55 
56 static const uint64_t kDefaultShadowScale = 3;
57 static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
58 static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
59 static const uint64_t kDefaultShort64bitShadowOffset = 0x7FFF8000; // < 2G.
60 static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 41;
61 static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa8000;
62 
63 static const size_t kMinStackMallocSize = 1 << 6; // 64B
64 static const size_t kMaxStackMallocSize = 1 << 16; // 64K
65 static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
66 static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;
67 
68 static const char *const kAsanModuleCtorName = "asan.module_ctor";
69 static const char *const kAsanModuleDtorName = "asan.module_dtor";
70 static const int kAsanCtorAndCtorPriority = 1;
71 static const char *const kAsanReportErrorTemplate = "__asan_report_";
72 static const char *const kAsanReportLoadN = "__asan_report_load_n";
73 static const char *const kAsanReportStoreN = "__asan_report_store_n";
74 static const char *const kAsanRegisterGlobalsName = "__asan_register_globals";
75 static const char *const kAsanUnregisterGlobalsName =
76  "__asan_unregister_globals";
77 static const char *const kAsanPoisonGlobalsName = "__asan_before_dynamic_init";
78 static const char *const kAsanUnpoisonGlobalsName = "__asan_after_dynamic_init";
79 static const char *const kAsanInitName = "__asan_init_v3";
80 static const char *const kAsanCovName = "__sanitizer_cov";
81 static const char *const kAsanHandleNoReturnName = "__asan_handle_no_return";
82 static const char *const kAsanMappingOffsetName = "__asan_mapping_offset";
83 static const char *const kAsanMappingScaleName = "__asan_mapping_scale";
84 static const int kMaxAsanStackMallocSizeClass = 10;
85 static const char *const kAsanStackMallocNameTemplate = "__asan_stack_malloc_";
86 static const char *const kAsanStackFreeNameTemplate = "__asan_stack_free_";
87 static const char *const kAsanGenPrefix = "__asan_gen_";
88 static const char *const kAsanPoisonStackMemoryName =
89  "__asan_poison_stack_memory";
90 static const char *const kAsanUnpoisonStackMemoryName =
91  "__asan_unpoison_stack_memory";
92 
93 static const char *const kAsanOptionDetectUAR =
94  "__asan_option_detect_stack_use_after_return";
95 
96 // These constants must match the definitions in the run-time library.
97 static const int kAsanStackLeftRedzoneMagic = 0xf1;
98 static const int kAsanStackMidRedzoneMagic = 0xf2;
99 static const int kAsanStackRightRedzoneMagic = 0xf3;
100 static const int kAsanStackPartialRedzoneMagic = 0xf4;
101 #ifndef NDEBUG
102 static const int kAsanStackAfterReturnMagic = 0xf5;
103 #endif
104 
105 // Accesses sizes are powers of two: 1, 2, 4, 8, 16.
106 static const size_t kNumberOfAccessSizes = 5;
107 
108 // Command-line flags.
109 
110 // This flag may need to be replaced with -f[no-]asan-reads.
111 static cl::opt<bool> ClInstrumentReads("asan-instrument-reads",
112  cl::desc("instrument read instructions"), cl::Hidden, cl::init(true));
113 static cl::opt<bool> ClInstrumentWrites("asan-instrument-writes",
114  cl::desc("instrument write instructions"), cl::Hidden, cl::init(true));
115 static cl::opt<bool> ClInstrumentAtomics("asan-instrument-atomics",
116  cl::desc("instrument atomic instructions (rmw, cmpxchg)"),
117  cl::Hidden, cl::init(true));
118 static cl::opt<bool> ClAlwaysSlowPath("asan-always-slow-path",
119  cl::desc("use instrumentation with slow path for all accesses"),
120  cl::Hidden, cl::init(false));
121 // This flag limits the number of instructions to be instrumented
122 // in any given BB. Normally, this should be set to unlimited (INT_MAX),
123 // but due to http://llvm.org/bugs/show_bug.cgi?id=12652 we temporary
124 // set it to 10000.
125 static cl::opt<int> ClMaxInsnsToInstrumentPerBB("asan-max-ins-per-bb",
126  cl::init(10000),
127  cl::desc("maximal number of instructions to instrument in any given BB"),
128  cl::Hidden);
129 // This flag may need to be replaced with -f[no]asan-stack.
130 static cl::opt<bool> ClStack("asan-stack",
131  cl::desc("Handle stack memory"), cl::Hidden, cl::init(true));
132 // This flag may need to be replaced with -f[no]asan-use-after-return.
133 static cl::opt<bool> ClUseAfterReturn("asan-use-after-return",
134  cl::desc("Check return-after-free"), cl::Hidden, cl::init(false));
135 // This flag may need to be replaced with -f[no]asan-globals.
136 static cl::opt<bool> ClGlobals("asan-globals",
137  cl::desc("Handle global objects"), cl::Hidden, cl::init(true));
138 static cl::opt<bool> ClCoverage("asan-coverage",
139  cl::desc("ASan coverage"), cl::Hidden, cl::init(false));
140 static cl::opt<bool> ClInitializers("asan-initialization-order",
141  cl::desc("Handle C++ initializer order"), cl::Hidden, cl::init(false));
142 static cl::opt<bool> ClMemIntrin("asan-memintrin",
143  cl::desc("Handle memset/memcpy/memmove"), cl::Hidden, cl::init(true));
144 static cl::opt<bool> ClRealignStack("asan-realign-stack",
145  cl::desc("Realign stack to 32"), cl::Hidden, cl::init(true));
146 static cl::opt<std::string> ClBlacklistFile("asan-blacklist",
147  cl::desc("File containing the list of objects to ignore "
148  "during instrumentation"), cl::Hidden);
149 
150 // This is an experimental feature that will allow to choose between
151 // instrumented and non-instrumented code at link-time.
152 // If this option is on, just before instrumenting a function we create its
153 // clone; if the function is not changed by asan the clone is deleted.
154 // If we end up with a clone, we put the instrumented function into a section
155 // called "ASAN" and the uninstrumented function into a section called "NOASAN".
156 //
157 // This is still a prototype, we need to figure out a way to keep two copies of
158 // a function so that the linker can easily choose one of them.
159 static cl::opt<bool> ClKeepUninstrumented("asan-keep-uninstrumented-functions",
160  cl::desc("Keep uninstrumented copies of functions"),
161  cl::Hidden, cl::init(false));
162 
163 // These flags allow to change the shadow mapping.
164 // The shadow mapping looks like
165 // Shadow = (Mem >> scale) + (1 << offset_log)
166 static cl::opt<int> ClMappingScale("asan-mapping-scale",
167  cl::desc("scale of asan shadow mapping"), cl::Hidden, cl::init(0));
168 static cl::opt<int> ClMappingOffsetLog("asan-mapping-offset-log",
169  cl::desc("offset of asan shadow mapping"), cl::Hidden, cl::init(-1));
170 static cl::opt<bool> ClShort64BitOffset("asan-short-64bit-mapping-offset",
171  cl::desc("Use short immediate constant as the mapping offset for 64bit"),
172  cl::Hidden, cl::init(true));
173 
174 // Optimization flags. Not user visible, used mostly for testing
175 // and benchmarking the tool.
176 static cl::opt<bool> ClOpt("asan-opt",
177  cl::desc("Optimize instrumentation"), cl::Hidden, cl::init(true));
178 static cl::opt<bool> ClOptSameTemp("asan-opt-same-temp",
179  cl::desc("Instrument the same temp just once"), cl::Hidden,
180  cl::init(true));
181 static cl::opt<bool> ClOptGlobals("asan-opt-globals",
182  cl::desc("Don't instrument scalar globals"), cl::Hidden, cl::init(true));
183 
184 static cl::opt<bool> ClCheckLifetime("asan-check-lifetime",
185  cl::desc("Use llvm.lifetime intrinsics to insert extra checks"),
186  cl::Hidden, cl::init(false));
187 
188 // Debug flags.
189 static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
190  cl::init(0));
191 static cl::opt<int> ClDebugStack("asan-debug-stack", cl::desc("debug stack"),
192  cl::Hidden, cl::init(0));
193 static cl::opt<std::string> ClDebugFunc("asan-debug-func",
194  cl::Hidden, cl::desc("Debug func"));
195 static cl::opt<int> ClDebugMin("asan-debug-min", cl::desc("Debug min inst"),
196  cl::Hidden, cl::init(-1));
197 static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug man inst"),
198  cl::Hidden, cl::init(-1));
199 
200 STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
201 STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
202 STATISTIC(NumOptimizedAccessesToGlobalArray,
203  "Number of optimized accesses to global arrays");
204 STATISTIC(NumOptimizedAccessesToGlobalVar,
205  "Number of optimized accesses to global vars");
206 
207 namespace {
208 /// A set of dynamically initialized globals extracted from metadata.
209 class SetOfDynamicallyInitializedGlobals {
210  public:
211  void Init(Module& M) {
212  // Clang generates metadata identifying all dynamically initialized globals.
213  NamedMDNode *DynamicGlobals =
214  M.getNamedMetadata("llvm.asan.dynamically_initialized_globals");
215  if (!DynamicGlobals)
216  return;
217  for (int i = 0, n = DynamicGlobals->getNumOperands(); i < n; ++i) {
218  MDNode *MDN = DynamicGlobals->getOperand(i);
219  assert(MDN->getNumOperands() == 1);
220  Value *VG = MDN->getOperand(0);
221  // The optimizer may optimize away a global entirely, in which case we
222  // cannot instrument access to it.
223  if (!VG)
224  continue;
225  DynInitGlobals.insert(cast<GlobalVariable>(VG));
226  }
227  }
228  bool Contains(GlobalVariable *G) { return DynInitGlobals.count(G) != 0; }
229  private:
230  SmallSet<GlobalValue*, 32> DynInitGlobals;
231 };
232 
233 /// This struct defines the shadow mapping using the rule:
234 /// shadow = (mem >> Scale) ADD-or-OR Offset.
235 struct ShadowMapping {
236  int Scale;
237  uint64_t Offset;
238  bool OrShadowOffset;
239 };
240 
241 static ShadowMapping getShadowMapping(const Module &M, int LongSize,
242  bool ZeroBaseShadow) {
243  llvm::Triple TargetTriple(M.getTargetTriple());
244  bool IsAndroid = TargetTriple.getEnvironment() == llvm::Triple::Android;
245  bool IsMacOSX = TargetTriple.getOS() == llvm::Triple::MacOSX;
246  bool IsPPC64 = TargetTriple.getArch() == llvm::Triple::ppc64 ||
247  TargetTriple.getArch() == llvm::Triple::ppc64le;
248  bool IsX86_64 = TargetTriple.getArch() == llvm::Triple::x86_64;
249  bool IsMIPS32 = TargetTriple.getArch() == llvm::Triple::mips ||
250  TargetTriple.getArch() == llvm::Triple::mipsel;
251 
252  ShadowMapping Mapping;
253 
254  // OR-ing shadow offset if more efficient (at least on x86),
255  // but on ppc64 we have to use add since the shadow offset is not neccesary
256  // 1/8-th of the address space.
257  Mapping.OrShadowOffset = !IsPPC64 && !ClShort64BitOffset;
258 
259  Mapping.Offset = (IsAndroid || ZeroBaseShadow) ? 0 :
260  (LongSize == 32 ?
263  if (!ZeroBaseShadow && ClShort64BitOffset && IsX86_64 && !IsMacOSX) {
264  assert(LongSize == 64);
265  Mapping.Offset = kDefaultShort64bitShadowOffset;
266  }
267  if (!ZeroBaseShadow && ClMappingOffsetLog >= 0) {
268  // Zero offset log is the special case.
269  Mapping.Offset = (ClMappingOffsetLog == 0) ? 0 : 1ULL << ClMappingOffsetLog;
270  }
271 
272  Mapping.Scale = kDefaultShadowScale;
273  if (ClMappingScale) {
274  Mapping.Scale = ClMappingScale;
275  }
276 
277  return Mapping;
278 }
279 
280 static size_t RedzoneSizeForScale(int MappingScale) {
281  // Redzone used for stack and globals is at least 32 bytes.
282  // For scales 6 and 7, the redzone has to be 64 and 128 bytes respectively.
283  return std::max(32U, 1U << MappingScale);
284 }
285 
286 /// AddressSanitizer: instrument the code in module to find memory bugs.
287 struct AddressSanitizer : public FunctionPass {
288  AddressSanitizer(bool CheckInitOrder = true,
289  bool CheckUseAfterReturn = false,
290  bool CheckLifetime = false,
291  StringRef BlacklistFile = StringRef(),
292  bool ZeroBaseShadow = false)
293  : FunctionPass(ID),
294  CheckInitOrder(CheckInitOrder || ClInitializers),
295  CheckUseAfterReturn(CheckUseAfterReturn || ClUseAfterReturn),
296  CheckLifetime(CheckLifetime || ClCheckLifetime),
297  BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
298  : BlacklistFile),
299  ZeroBaseShadow(ZeroBaseShadow) {}
300  virtual const char *getPassName() const {
301  return "AddressSanitizerFunctionPass";
302  }
303  void instrumentMop(Instruction *I);
304  void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
305  Value *Addr, uint32_t TypeSize, bool IsWrite,
306  Value *SizeArgument);
307  Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
308  Value *ShadowValue, uint32_t TypeSize);
309  Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
310  bool IsWrite, size_t AccessSizeIndex,
311  Value *SizeArgument);
312  bool instrumentMemIntrinsic(MemIntrinsic *MI);
313  void instrumentMemIntrinsicParam(Instruction *OrigIns, Value *Addr,
314  Value *Size,
315  Instruction *InsertBefore, bool IsWrite);
316  Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
317  bool runOnFunction(Function &F);
318  bool maybeInsertAsanInitAtFunctionEntry(Function &F);
319  void emitShadowMapping(Module &M, IRBuilder<> &IRB) const;
320  virtual bool doInitialization(Module &M);
321  static char ID; // Pass identification, replacement for typeid
322 
323  private:
324  void initializeCallbacks(Module &M);
325 
326  bool ShouldInstrumentGlobal(GlobalVariable *G);
327  bool LooksLikeCodeInBug11395(Instruction *I);
328  void FindDynamicInitializers(Module &M);
329  bool GlobalIsLinkerInitialized(GlobalVariable *G);
330  bool InjectCoverage(Function &F);
331 
332  bool CheckInitOrder;
333  bool CheckUseAfterReturn;
334  bool CheckLifetime;
335  SmallString<64> BlacklistFile;
336  bool ZeroBaseShadow;
337 
338  LLVMContext *C;
339  DataLayout *TD;
340  int LongSize;
341  Type *IntptrTy;
342  ShadowMapping Mapping;
343  Function *AsanCtorFunction;
344  Function *AsanInitFunction;
345  Function *AsanHandleNoReturnFunc;
346  Function *AsanCovFunction;
348  // This array is indexed by AccessIsWrite and log2(AccessSize).
349  Function *AsanErrorCallback[2][kNumberOfAccessSizes];
350  // This array is indexed by AccessIsWrite.
351  Function *AsanErrorCallbackSized[2];
352  InlineAsm *EmptyAsm;
353  SetOfDynamicallyInitializedGlobals DynamicallyInitializedGlobals;
354 
355  friend struct FunctionStackPoisoner;
356 };
357 
358 class AddressSanitizerModule : public ModulePass {
359  public:
360  AddressSanitizerModule(bool CheckInitOrder = true,
361  StringRef BlacklistFile = StringRef(),
362  bool ZeroBaseShadow = false)
363  : ModulePass(ID),
364  CheckInitOrder(CheckInitOrder || ClInitializers),
365  BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
366  : BlacklistFile),
367  ZeroBaseShadow(ZeroBaseShadow) {}
368  bool runOnModule(Module &M);
369  static char ID; // Pass identification, replacement for typeid
370  virtual const char *getPassName() const {
371  return "AddressSanitizerModule";
372  }
373 
374  private:
375  void initializeCallbacks(Module &M);
376 
377  bool ShouldInstrumentGlobal(GlobalVariable *G);
378  void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
379  size_t RedzoneSize() const {
380  return RedzoneSizeForScale(Mapping.Scale);
381  }
382 
383  bool CheckInitOrder;
384  SmallString<64> BlacklistFile;
385  bool ZeroBaseShadow;
386 
388  SetOfDynamicallyInitializedGlobals DynamicallyInitializedGlobals;
389  Type *IntptrTy;
390  LLVMContext *C;
391  DataLayout *TD;
392  ShadowMapping Mapping;
393  Function *AsanPoisonGlobals;
394  Function *AsanUnpoisonGlobals;
395  Function *AsanRegisterGlobals;
396  Function *AsanUnregisterGlobals;
397 };
398 
399 // Stack poisoning does not play well with exception handling.
400 // When an exception is thrown, we essentially bypass the code
401 // that unpoisones the stack. This is why the run-time library has
402 // to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
403 // stack in the interceptor. This however does not work inside the
404 // actual function which catches the exception. Most likely because the
405 // compiler hoists the load of the shadow value somewhere too high.
406 // This causes asan to report a non-existing bug on 453.povray.
407 // It sounds like an LLVM bug.
408 struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
409  Function &F;
410  AddressSanitizer &ASan;
411  DIBuilder DIB;
412  LLVMContext *C;
413  Type *IntptrTy;
414  Type *IntptrPtrTy;
415  ShadowMapping Mapping;
416 
419  uint64_t TotalStackSize;
420  unsigned StackAlignment;
421 
422  Function *AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
423  *AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
424  Function *AsanPoisonStackMemoryFunc, *AsanUnpoisonStackMemoryFunc;
425 
426  // Stores a place and arguments of poisoning/unpoisoning call for alloca.
427  struct AllocaPoisonCall {
428  IntrinsicInst *InsBefore;
429  AllocaInst *AI;
430  uint64_t Size;
431  bool DoPoison;
432  };
433  SmallVector<AllocaPoisonCall, 8> AllocaPoisonCallVec;
434 
435  // Maps Value to an AllocaInst from which the Value is originated.
436  typedef DenseMap<Value*, AllocaInst*> AllocaForValueMapTy;
437  AllocaForValueMapTy AllocaForValue;
438 
439  FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
440  : F(F), ASan(ASan), DIB(*F.getParent()), C(ASan.C),
441  IntptrTy(ASan.IntptrTy), IntptrPtrTy(PointerType::get(IntptrTy, 0)),
442  Mapping(ASan.Mapping),
443  TotalStackSize(0), StackAlignment(1 << Mapping.Scale) {}
444 
445  bool runOnFunction() {
446  if (!ClStack) return false;
447  // Collect alloca, ret, lifetime instructions etc.
448  for (df_iterator<BasicBlock*> DI = df_begin(&F.getEntryBlock()),
449  DE = df_end(&F.getEntryBlock()); DI != DE; ++DI) {
450  BasicBlock *BB = *DI;
451  visit(*BB);
452  }
453  if (AllocaVec.empty()) return false;
454 
455  initializeCallbacks(*F.getParent());
456 
457  poisonStack();
458 
459  if (ClDebugStack) {
460  DEBUG(dbgs() << F);
461  }
462  return true;
463  }
464 
465  // Finds all static Alloca instructions and puts
466  // poisoned red zones around all of them.
467  // Then unpoison everything back before the function returns.
468  void poisonStack();
469 
470  // ----------------------- Visitors.
471  /// \brief Collect all Ret instructions.
472  void visitReturnInst(ReturnInst &RI) {
473  RetVec.push_back(&RI);
474  }
475 
476  /// \brief Collect Alloca instructions we want (and can) handle.
477  void visitAllocaInst(AllocaInst &AI) {
478  if (!isInterestingAlloca(AI)) return;
479 
480  StackAlignment = std::max(StackAlignment, AI.getAlignment());
481  AllocaVec.push_back(&AI);
482  uint64_t AlignedSize = getAlignedAllocaSize(&AI);
483  TotalStackSize += AlignedSize;
484  }
485 
486  /// \brief Collect lifetime intrinsic calls to check for use-after-scope
487  /// errors.
488  void visitIntrinsicInst(IntrinsicInst &II) {
489  if (!ASan.CheckLifetime) return;
491  if (ID != Intrinsic::lifetime_start &&
493  return;
494  // Found lifetime intrinsic, add ASan instrumentation if necessary.
496  // If size argument is undefined, don't do anything.
497  if (Size->isMinusOne()) return;
498  // Check that size doesn't saturate uint64_t and can
499  // be stored in IntptrTy.
500  const uint64_t SizeValue = Size->getValue().getLimitedValue();
501  if (SizeValue == ~0ULL ||
502  !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
503  return;
504  // Find alloca instruction that corresponds to llvm.lifetime argument.
505  AllocaInst *AI = findAllocaForValue(II.getArgOperand(1));
506  if (!AI) return;
507  bool DoPoison = (ID == Intrinsic::lifetime_end);
508  AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
509  AllocaPoisonCallVec.push_back(APC);
510  }
511 
512  // ---------------------- Helpers.
513  void initializeCallbacks(Module &M);
514 
515  // Check if we want (and can) handle this alloca.
516  bool isInterestingAlloca(AllocaInst &AI) const {
517  return (!AI.isArrayAllocation() &&
518  AI.isStaticAlloca() &&
519  AI.getAlignment() <= RedzoneSize() &&
520  AI.getAllocatedType()->isSized());
521  }
522 
523  size_t RedzoneSize() const {
524  return RedzoneSizeForScale(Mapping.Scale);
525  }
526  uint64_t getAllocaSizeInBytes(AllocaInst *AI) const {
527  Type *Ty = AI->getAllocatedType();
528  uint64_t SizeInBytes = ASan.TD->getTypeAllocSize(Ty);
529  return SizeInBytes;
530  }
531  uint64_t getAlignedSize(uint64_t SizeInBytes) const {
532  size_t RZ = RedzoneSize();
533  return ((SizeInBytes + RZ - 1) / RZ) * RZ;
534  }
535  uint64_t getAlignedAllocaSize(AllocaInst *AI) const {
536  uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
537  return getAlignedSize(SizeInBytes);
538  }
539  /// Finds alloca where the value comes from.
540  AllocaInst *findAllocaForValue(Value *V);
541  void poisonRedZones(const ArrayRef<AllocaInst*> &AllocaVec, IRBuilder<> &IRB,
542  Value *ShadowBase, bool DoPoison);
543  void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
544 
545  void SetShadowToStackAfterReturnInlined(IRBuilder<> &IRB, Value *ShadowBase,
546  int Size);
547 };
548 
549 } // namespace
550 
551 char AddressSanitizer::ID = 0;
552 INITIALIZE_PASS(AddressSanitizer, "asan",
553  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.",
554  false, false)
556  bool CheckInitOrder, bool CheckUseAfterReturn, bool CheckLifetime,
557  StringRef BlacklistFile, bool ZeroBaseShadow) {
558  return new AddressSanitizer(CheckInitOrder, CheckUseAfterReturn,
559  CheckLifetime, BlacklistFile, ZeroBaseShadow);
560 }
561 
563 INITIALIZE_PASS(AddressSanitizerModule, "asan-module",
564  "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
565  "ModulePass", false, false)
567  bool CheckInitOrder, StringRef BlacklistFile, bool ZeroBaseShadow) {
568  return new AddressSanitizerModule(CheckInitOrder, BlacklistFile,
569  ZeroBaseShadow);
570 }
571 
572 static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
573  size_t Res = countTrailingZeros(TypeSize / 8);
574  assert(Res < kNumberOfAccessSizes);
575  return Res;
576 }
577 
578 // \brief Create a constant for Str so that we can pass it to the run-time lib.
580  Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
581  GlobalVariable *GV = new GlobalVariable(M, StrConst->getType(), true,
584  GV->setUnnamedAddr(true); // Ok to merge these.
585  GV->setAlignment(1); // Strings may not be merged w/o setting align 1.
586  return GV;
587 }
588 
590  return G->getName().find(kAsanGenPrefix) == 0;
591 }
592 
593 Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
594  // Shadow >> scale
595  Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
596  if (Mapping.Offset == 0)
597  return Shadow;
598  // (Shadow >> scale) | offset
599  if (Mapping.OrShadowOffset)
600  return IRB.CreateOr(Shadow, ConstantInt::get(IntptrTy, Mapping.Offset));
601  else
602  return IRB.CreateAdd(Shadow, ConstantInt::get(IntptrTy, Mapping.Offset));
603 }
604 
605 void AddressSanitizer::instrumentMemIntrinsicParam(
606  Instruction *OrigIns,
607  Value *Addr, Value *Size, Instruction *InsertBefore, bool IsWrite) {
608  IRBuilder<> IRB(InsertBefore);
609  if (Size->getType() != IntptrTy)
610  Size = IRB.CreateIntCast(Size, IntptrTy, false);
611  // Check the first byte.
612  instrumentAddress(OrigIns, InsertBefore, Addr, 8, IsWrite, Size);
613  // Check the last byte.
614  IRB.SetInsertPoint(InsertBefore);
615  Value *SizeMinusOne = IRB.CreateSub(Size, ConstantInt::get(IntptrTy, 1));
616  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
617  Value *AddrLast = IRB.CreateAdd(AddrLong, SizeMinusOne);
618  instrumentAddress(OrigIns, InsertBefore, AddrLast, 8, IsWrite, Size);
619 }
620 
621 // Instrument memset/memmove/memcpy
622 bool AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
623  Value *Dst = MI->getDest();
625  Value *Src = MemTran ? MemTran->getSource() : 0;
626  Value *Length = MI->getLength();
627 
628  Constant *ConstLength = dyn_cast<Constant>(Length);
629  Instruction *InsertBefore = MI;
630  if (ConstLength) {
631  if (ConstLength->isNullValue()) return false;
632  } else {
633  // The size is not a constant so it could be zero -- check at run-time.
634  IRBuilder<> IRB(InsertBefore);
635 
636  Value *Cmp = IRB.CreateICmpNE(Length,
637  Constant::getNullValue(Length->getType()));
638  InsertBefore = SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), false);
639  }
640 
641  instrumentMemIntrinsicParam(MI, Dst, Length, InsertBefore, true);
642  if (Src)
643  instrumentMemIntrinsicParam(MI, Src, Length, InsertBefore, false);
644  return true;
645 }
646 
647 // If I is an interesting memory access, return the PointerOperand
648 // and set IsWrite. Otherwise return NULL.
649 static Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite) {
650  if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
651  if (!ClInstrumentReads) return NULL;
652  *IsWrite = false;
653  return LI->getPointerOperand();
654  }
655  if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
656  if (!ClInstrumentWrites) return NULL;
657  *IsWrite = true;
658  return SI->getPointerOperand();
659  }
660  if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
661  if (!ClInstrumentAtomics) return NULL;
662  *IsWrite = true;
663  return RMW->getPointerOperand();
664  }
665  if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
666  if (!ClInstrumentAtomics) return NULL;
667  *IsWrite = true;
668  return XCHG->getPointerOperand();
669  }
670  return NULL;
671 }
672 
673 bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
674  // If a global variable does not have dynamic initialization we don't
675  // have to instrument it. However, if a global does not have initializer
676  // at all, we assume it has dynamic initializer (in other TU).
677  return G->hasInitializer() && !DynamicallyInitializedGlobals.Contains(G);
678 }
679 
680 void AddressSanitizer::instrumentMop(Instruction *I) {
681  bool IsWrite = false;
682  Value *Addr = isInterestingMemoryAccess(I, &IsWrite);
683  assert(Addr);
684  if (ClOpt && ClOptGlobals) {
685  if (GlobalVariable *G = dyn_cast<GlobalVariable>(Addr)) {
686  // If initialization order checking is disabled, a simple access to a
687  // dynamically initialized global is always valid.
688  if (!CheckInitOrder || GlobalIsLinkerInitialized(G)) {
689  NumOptimizedAccessesToGlobalVar++;
690  return;
691  }
692  }
693  ConstantExpr *CE = dyn_cast<ConstantExpr>(Addr);
694  if (CE && CE->isGEPWithNoNotionalOverIndexing()) {
695  if (GlobalVariable *G = dyn_cast<GlobalVariable>(CE->getOperand(0))) {
696  if (CE->getOperand(1)->isNullValue() && GlobalIsLinkerInitialized(G)) {
697  NumOptimizedAccessesToGlobalArray++;
698  return;
699  }
700  }
701  }
702  }
703 
704  Type *OrigPtrTy = Addr->getType();
705  Type *OrigTy = cast<PointerType>(OrigPtrTy)->getElementType();
706 
707  assert(OrigTy->isSized());
708  uint32_t TypeSize = TD->getTypeStoreSizeInBits(OrigTy);
709 
710  assert((TypeSize % 8) == 0);
711 
712  if (IsWrite)
713  NumInstrumentedWrites++;
714  else
715  NumInstrumentedReads++;
716 
717  // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check.
718  if (TypeSize == 8 || TypeSize == 16 ||
719  TypeSize == 32 || TypeSize == 64 || TypeSize == 128)
720  return instrumentAddress(I, I, Addr, TypeSize, IsWrite, 0);
721  // Instrument unusual size (but still multiple of 8).
722  // We can not do it with a single check, so we do 1-byte check for the first
723  // and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
724  // to report the actual access size.
725  IRBuilder<> IRB(I);
726  Value *LastByte = IRB.CreateIntToPtr(
727  IRB.CreateAdd(IRB.CreatePointerCast(Addr, IntptrTy),
728  ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
729  OrigPtrTy);
730  Value *Size = ConstantInt::get(IntptrTy, TypeSize / 8);
731  instrumentAddress(I, I, Addr, 8, IsWrite, Size);
732  instrumentAddress(I, I, LastByte, 8, IsWrite, Size);
733 }
734 
735 // Validate the result of Module::getOrInsertFunction called for an interface
736 // function of AddressSanitizer. If the instrumented module defines a function
737 // with the same name, their prototypes must match, otherwise
738 // getOrInsertFunction returns a bitcast.
739 static Function *checkInterfaceFunction(Constant *FuncOrBitcast) {
740  if (isa<Function>(FuncOrBitcast)) return cast<Function>(FuncOrBitcast);
741  FuncOrBitcast->dump();
742  report_fatal_error("trying to redefine an AddressSanitizer "
743  "interface function");
744 }
745 
746 Instruction *AddressSanitizer::generateCrashCode(
747  Instruction *InsertBefore, Value *Addr,
748  bool IsWrite, size_t AccessSizeIndex, Value *SizeArgument) {
749  IRBuilder<> IRB(InsertBefore);
750  CallInst *Call = SizeArgument
751  ? IRB.CreateCall2(AsanErrorCallbackSized[IsWrite], Addr, SizeArgument)
752  : IRB.CreateCall(AsanErrorCallback[IsWrite][AccessSizeIndex], Addr);
753 
754  // We don't do Call->setDoesNotReturn() because the BB already has
755  // UnreachableInst at the end.
756  // This EmptyAsm is required to avoid callback merge.
757  IRB.CreateCall(EmptyAsm);
758  return Call;
759 }
760 
761 Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
762  Value *ShadowValue,
763  uint32_t TypeSize) {
764  size_t Granularity = 1 << Mapping.Scale;
765  // Addr & (Granularity - 1)
766  Value *LastAccessedByte = IRB.CreateAnd(
767  AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
768  // (Addr & (Granularity - 1)) + size - 1
769  if (TypeSize / 8 > 1)
770  LastAccessedByte = IRB.CreateAdd(
771  LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1));
772  // (uint8_t) ((Addr & (Granularity-1)) + size - 1)
773  LastAccessedByte = IRB.CreateIntCast(
774  LastAccessedByte, ShadowValue->getType(), false);
775  // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
776  return IRB.CreateICmpSGE(LastAccessedByte, ShadowValue);
777 }
778 
779 void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
780  Instruction *InsertBefore,
781  Value *Addr, uint32_t TypeSize,
782  bool IsWrite, Value *SizeArgument) {
783  IRBuilder<> IRB(InsertBefore);
784  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
785 
786  Type *ShadowTy = IntegerType::get(
787  *C, std::max(8U, TypeSize >> Mapping.Scale));
788  Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
789  Value *ShadowPtr = memToShadow(AddrLong, IRB);
790  Value *CmpVal = Constant::getNullValue(ShadowTy);
791  Value *ShadowValue = IRB.CreateLoad(
792  IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));
793 
794  Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
795  size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
796  size_t Granularity = 1 << Mapping.Scale;
797  TerminatorInst *CrashTerm = 0;
798 
799  if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
800  TerminatorInst *CheckTerm =
801  SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), false);
802  assert(dyn_cast<BranchInst>(CheckTerm)->isUnconditional());
803  BasicBlock *NextBB = CheckTerm->getSuccessor(0);
804  IRB.SetInsertPoint(CheckTerm);
805  Value *Cmp2 = createSlowPathCmp(IRB, AddrLong, ShadowValue, TypeSize);
806  BasicBlock *CrashBlock =
807  BasicBlock::Create(*C, "", NextBB->getParent(), NextBB);
808  CrashTerm = new UnreachableInst(*C, CrashBlock);
809  BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
810  ReplaceInstWithInst(CheckTerm, NewTerm);
811  } else {
812  CrashTerm = SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), true);
813  }
814 
815  Instruction *Crash = generateCrashCode(
816  CrashTerm, AddrLong, IsWrite, AccessSizeIndex, SizeArgument);
817  Crash->setDebugLoc(OrigIns->getDebugLoc());
818 }
819 
820 void AddressSanitizerModule::createInitializerPoisonCalls(
821  Module &M, GlobalValue *ModuleName) {
822  // We do all of our poisoning and unpoisoning within _GLOBAL__I_a.
823  Function *GlobalInit = M.getFunction("_GLOBAL__I_a");
824  // If that function is not present, this TU contains no globals, or they have
825  // all been optimized away
826  if (!GlobalInit)
827  return;
828 
829  // Set up the arguments to our poison/unpoison functions.
830  IRBuilder<> IRB(GlobalInit->begin()->getFirstInsertionPt());
831 
832  // Add a call to poison all external globals before the given function starts.
833  Value *ModuleNameAddr = ConstantExpr::getPointerCast(ModuleName, IntptrTy);
834  IRB.CreateCall(AsanPoisonGlobals, ModuleNameAddr);
835 
836  // Add calls to unpoison all globals before each return instruction.
837  for (Function::iterator I = GlobalInit->begin(), E = GlobalInit->end();
838  I != E; ++I) {
839  if (ReturnInst *RI = dyn_cast<ReturnInst>(I->getTerminator())) {
840  CallInst::Create(AsanUnpoisonGlobals, "", RI);
841  }
842  }
843 }
844 
845 bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
846  Type *Ty = cast<PointerType>(G->getType())->getElementType();
847  DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
848 
849  if (BL->isIn(*G)) return false;
850  if (!Ty->isSized()) return false;
851  if (!G->hasInitializer()) return false;
852  if (GlobalWasGeneratedByAsan(G)) return false; // Our own global.
853  // Touch only those globals that will not be defined in other modules.
854  // Don't handle ODR type linkages since other modules may be built w/o asan.
858  return false;
859  // Two problems with thread-locals:
860  // - The address of the main thread's copy can't be computed at link-time.
861  // - Need to poison all copies, not just the main thread's one.
862  if (G->isThreadLocal())
863  return false;
864  // For now, just ignore this Alloca if the alignment is large.
865  if (G->getAlignment() > RedzoneSize()) return false;
866 
867  // Ignore all the globals with the names starting with "\01L_OBJC_".
868  // Many of those are put into the .cstring section. The linker compresses
869  // that section by removing the spare \0s after the string terminator, so
870  // our redzones get broken.
871  if ((G->getName().find("\01L_OBJC_") == 0) ||
872  (G->getName().find("\01l_OBJC_") == 0)) {
873  DEBUG(dbgs() << "Ignoring \\01L_OBJC_* global: " << *G);
874  return false;
875  }
876 
877  if (G->hasSection()) {
879  // Ignore the globals from the __OBJC section. The ObjC runtime assumes
880  // those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
881  // them.
882  if ((Section.find("__OBJC,") == 0) ||
883  (Section.find("__DATA, __objc_") == 0)) {
884  DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G);
885  return false;
886  }
887  // See http://code.google.com/p/address-sanitizer/issues/detail?id=32
888  // Constant CFString instances are compiled in the following way:
889  // -- the string buffer is emitted into
890  // __TEXT,__cstring,cstring_literals
891  // -- the constant NSConstantString structure referencing that buffer
892  // is placed into __DATA,__cfstring
893  // Therefore there's no point in placing redzones into __DATA,__cfstring.
894  // Moreover, it causes the linker to crash on OS X 10.7
895  if (Section.find("__DATA,__cfstring") == 0) {
896  DEBUG(dbgs() << "Ignoring CFString: " << *G);
897  return false;
898  }
899  }
900 
901  return true;
902 }
903 
904 void AddressSanitizerModule::initializeCallbacks(Module &M) {
905  IRBuilder<> IRB(*C);
906  // Declare our poisoning and unpoisoning functions.
907  AsanPoisonGlobals = checkInterfaceFunction(M.getOrInsertFunction(
908  kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy, NULL));
909  AsanPoisonGlobals->setLinkage(Function::ExternalLinkage);
910  AsanUnpoisonGlobals = checkInterfaceFunction(M.getOrInsertFunction(
911  kAsanUnpoisonGlobalsName, IRB.getVoidTy(), NULL));
912  AsanUnpoisonGlobals->setLinkage(Function::ExternalLinkage);
913  // Declare functions that register/unregister globals.
914  AsanRegisterGlobals = checkInterfaceFunction(M.getOrInsertFunction(
916  IntptrTy, IntptrTy, NULL));
917  AsanRegisterGlobals->setLinkage(Function::ExternalLinkage);
918  AsanUnregisterGlobals = checkInterfaceFunction(M.getOrInsertFunction(
920  IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
921  AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
922 }
923 
924 // This function replaces all global variables with new variables that have
925 // trailing redzones. It also creates a function that poisons
926 // redzones and inserts this function into llvm.global_ctors.
927 bool AddressSanitizerModule::runOnModule(Module &M) {
928  if (!ClGlobals) return false;
929  TD = getAnalysisIfAvailable<DataLayout>();
930  if (!TD)
931  return false;
932  BL.reset(SpecialCaseList::createOrDie(BlacklistFile));
933  if (BL->isIn(M)) return false;
934  C = &(M.getContext());
935  int LongSize = TD->getPointerSizeInBits();
936  IntptrTy = Type::getIntNTy(*C, LongSize);
937  Mapping = getShadowMapping(M, LongSize, ZeroBaseShadow);
938  initializeCallbacks(M);
939  DynamicallyInitializedGlobals.Init(M);
940 
941  SmallVector<GlobalVariable *, 16> GlobalsToChange;
942 
944  E = M.global_end(); G != E; ++G) {
945  if (ShouldInstrumentGlobal(G))
946  GlobalsToChange.push_back(G);
947  }
948 
949  size_t n = GlobalsToChange.size();
950  if (n == 0) return false;
951 
952  // A global is described by a structure
953  // size_t beg;
954  // size_t size;
955  // size_t size_with_redzone;
956  // const char *name;
957  // const char *module_name;
958  // size_t has_dynamic_init;
959  // We initialize an array of such structures and pass it to a run-time call.
960  StructType *GlobalStructTy = StructType::get(IntptrTy, IntptrTy,
961  IntptrTy, IntptrTy,
962  IntptrTy, IntptrTy, NULL);
963  SmallVector<Constant *, 16> Initializers(n);
964 
966  assert(CtorFunc);
967  IRBuilder<> IRB(CtorFunc->getEntryBlock().getTerminator());
968 
969  bool HasDynamicallyInitializedGlobals = false;
970 
972  M, M.getModuleIdentifier());
973  // We shouldn't merge same module names, as this string serves as unique
974  // module ID in runtime.
975  ModuleName->setUnnamedAddr(false);
976 
977  for (size_t i = 0; i < n; i++) {
978  static const uint64_t kMaxGlobalRedzone = 1 << 18;
979  GlobalVariable *G = GlobalsToChange[i];
980  PointerType *PtrTy = cast<PointerType>(G->getType());
981  Type *Ty = PtrTy->getElementType();
982  uint64_t SizeInBytes = TD->getTypeAllocSize(Ty);
983  uint64_t MinRZ = RedzoneSize();
984  // MinRZ <= RZ <= kMaxGlobalRedzone
985  // and trying to make RZ to be ~ 1/4 of SizeInBytes.
986  uint64_t RZ = std::max(MinRZ,
987  std::min(kMaxGlobalRedzone,
988  (SizeInBytes / MinRZ / 4) * MinRZ));
989  uint64_t RightRedzoneSize = RZ;
990  // Round up to MinRZ
991  if (SizeInBytes % MinRZ)
992  RightRedzoneSize += MinRZ - (SizeInBytes % MinRZ);
993  assert(((RightRedzoneSize + SizeInBytes) % MinRZ) == 0);
994  Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
995  // Determine whether this global should be poisoned in initialization.
996  bool GlobalHasDynamicInitializer =
997  DynamicallyInitializedGlobals.Contains(G);
998  // Don't check initialization order if this global is blacklisted.
999  GlobalHasDynamicInitializer &= !BL->isIn(*G, "init");
1000 
1001  StructType *NewTy = StructType::get(Ty, RightRedZoneTy, NULL);
1002  Constant *NewInitializer = ConstantStruct::get(
1003  NewTy, G->getInitializer(),
1004  Constant::getNullValue(RightRedZoneTy), NULL);
1005 
1007 
1008  // Create a new global variable with enough space for a redzone.
1009  GlobalValue::LinkageTypes Linkage = G->getLinkage();
1010  if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
1011  Linkage = GlobalValue::InternalLinkage;
1012  GlobalVariable *NewGlobal = new GlobalVariable(
1013  M, NewTy, G->isConstant(), Linkage,
1014  NewInitializer, "", G, G->getThreadLocalMode());
1015  NewGlobal->copyAttributesFrom(G);
1016  NewGlobal->setAlignment(MinRZ);
1017 
1018  Value *Indices2[2];
1019  Indices2[0] = IRB.getInt32(0);
1020  Indices2[1] = IRB.getInt32(0);
1021 
1022  G->replaceAllUsesWith(
1023  ConstantExpr::getGetElementPtr(NewGlobal, Indices2, true));
1024  NewGlobal->takeName(G);
1025  G->eraseFromParent();
1026 
1027  Initializers[i] = ConstantStruct::get(
1028  GlobalStructTy,
1029  ConstantExpr::getPointerCast(NewGlobal, IntptrTy),
1030  ConstantInt::get(IntptrTy, SizeInBytes),
1031  ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
1032  ConstantExpr::getPointerCast(Name, IntptrTy),
1033  ConstantExpr::getPointerCast(ModuleName, IntptrTy),
1034  ConstantInt::get(IntptrTy, GlobalHasDynamicInitializer),
1035  NULL);
1036 
1037  // Populate the first and last globals declared in this TU.
1038  if (CheckInitOrder && GlobalHasDynamicInitializer)
1039  HasDynamicallyInitializedGlobals = true;
1040 
1041  DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
1042  }
1043 
1044  ArrayType *ArrayOfGlobalStructTy = ArrayType::get(GlobalStructTy, n);
1045  GlobalVariable *AllGlobals = new GlobalVariable(
1046  M, ArrayOfGlobalStructTy, false, GlobalVariable::InternalLinkage,
1047  ConstantArray::get(ArrayOfGlobalStructTy, Initializers), "");
1048 
1049  // Create calls for poisoning before initializers run and unpoisoning after.
1050  if (CheckInitOrder && HasDynamicallyInitializedGlobals)
1051  createInitializerPoisonCalls(M, ModuleName);
1052  IRB.CreateCall2(AsanRegisterGlobals,
1053  IRB.CreatePointerCast(AllGlobals, IntptrTy),
1054  ConstantInt::get(IntptrTy, n));
1055 
1056  // We also need to unregister globals at the end, e.g. when a shared library
1057  // gets closed.
1058  Function *AsanDtorFunction = Function::Create(
1061  BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
1062  IRBuilder<> IRB_Dtor(ReturnInst::Create(*C, AsanDtorBB));
1063  IRB_Dtor.CreateCall2(AsanUnregisterGlobals,
1064  IRB.CreatePointerCast(AllGlobals, IntptrTy),
1065  ConstantInt::get(IntptrTy, n));
1066  appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndCtorPriority);
1067 
1068  DEBUG(dbgs() << M);
1069  return true;
1070 }
1071 
1072 void AddressSanitizer::initializeCallbacks(Module &M) {
1073  IRBuilder<> IRB(*C);
1074  // Create __asan_report* callbacks.
1075  for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
1076  for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
1077  AccessSizeIndex++) {
1078  // IsWrite and TypeSize are encoded in the function name.
1079  std::string FunctionName = std::string(kAsanReportErrorTemplate) +
1080  (AccessIsWrite ? "store" : "load") + itostr(1 << AccessSizeIndex);
1081  // If we are merging crash callbacks, they have two parameters.
1082  AsanErrorCallback[AccessIsWrite][AccessSizeIndex] =
1084  FunctionName, IRB.getVoidTy(), IntptrTy, NULL));
1085  }
1086  }
1087  AsanErrorCallbackSized[0] = checkInterfaceFunction(M.getOrInsertFunction(
1088  kAsanReportLoadN, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
1089  AsanErrorCallbackSized[1] = checkInterfaceFunction(M.getOrInsertFunction(
1090  kAsanReportStoreN, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
1091 
1092  AsanHandleNoReturnFunc = checkInterfaceFunction(M.getOrInsertFunction(
1093  kAsanHandleNoReturnName, IRB.getVoidTy(), NULL));
1094  AsanCovFunction = checkInterfaceFunction(M.getOrInsertFunction(
1095  kAsanCovName, IRB.getVoidTy(), IntptrTy, NULL));
1096  // We insert an empty inline asm after __asan_report* to avoid callback merge.
1097  EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
1098  StringRef(""), StringRef(""),
1099  /*hasSideEffects=*/true);
1100 }
1101 
1102 void AddressSanitizer::emitShadowMapping(Module &M, IRBuilder<> &IRB) const {
1103  // Tell the values of mapping offset and scale to the run-time.
1104  GlobalValue *asan_mapping_offset =
1105  new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
1106  ConstantInt::get(IntptrTy, Mapping.Offset),
1108  // Read the global, otherwise it may be optimized away.
1109  IRB.CreateLoad(asan_mapping_offset, true);
1110 
1111  GlobalValue *asan_mapping_scale =
1112  new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
1113  ConstantInt::get(IntptrTy, Mapping.Scale),
1115  // Read the global, otherwise it may be optimized away.
1116  IRB.CreateLoad(asan_mapping_scale, true);
1117 }
1118 
1119 // virtual
1120 bool AddressSanitizer::doInitialization(Module &M) {
1121  // Initialize the private fields. No one has accessed them before.
1122  TD = getAnalysisIfAvailable<DataLayout>();
1123 
1124  if (!TD)
1125  return false;
1126  BL.reset(SpecialCaseList::createOrDie(BlacklistFile));
1127  DynamicallyInitializedGlobals.Init(M);
1128 
1129  C = &(M.getContext());
1130  LongSize = TD->getPointerSizeInBits();
1131  IntptrTy = Type::getIntNTy(*C, LongSize);
1132 
1133  AsanCtorFunction = Function::Create(
1136  BasicBlock *AsanCtorBB = BasicBlock::Create(*C, "", AsanCtorFunction);
1137  // call __asan_init in the module ctor.
1138  IRBuilder<> IRB(ReturnInst::Create(*C, AsanCtorBB));
1139  AsanInitFunction = checkInterfaceFunction(
1140  M.getOrInsertFunction(kAsanInitName, IRB.getVoidTy(), NULL));
1141  AsanInitFunction->setLinkage(Function::ExternalLinkage);
1142  IRB.CreateCall(AsanInitFunction);
1143 
1144  Mapping = getShadowMapping(M, LongSize, ZeroBaseShadow);
1145  emitShadowMapping(M, IRB);
1146 
1147  appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndCtorPriority);
1148  return true;
1149 }
1150 
1151 bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
1152  // For each NSObject descendant having a +load method, this method is invoked
1153  // by the ObjC runtime before any of the static constructors is called.
1154  // Therefore we need to instrument such methods with a call to __asan_init
1155  // at the beginning in order to initialize our runtime before any access to
1156  // the shadow memory.
1157  // We cannot just ignore these methods, because they may call other
1158  // instrumented functions.
1159  if (F.getName().find(" load]") != std::string::npos) {
1160  IRBuilder<> IRB(F.begin()->begin());
1161  IRB.CreateCall(AsanInitFunction);
1162  return true;
1163  }
1164  return false;
1165 }
1166 
1167 // Poor man's coverage that works with ASan.
1168 // We create a Guard boolean variable with the same linkage
1169 // as the function and inject this code into the entry block:
1170 // if (*Guard) {
1171 // __sanitizer_cov(&F);
1172 // *Guard = 1;
1173 // }
1174 // The accesses to Guard are atomic. The rest of the logic is
1175 // in __sanitizer_cov (it's fine to call it more than once).
1176 //
1177 // This coverage implementation provides very limited data:
1178 // it only tells if a given function was ever executed.
1179 // No counters, no per-basic-block or per-edge data.
1180 // But for many use cases this is what we need and the added slowdown
1181 // is negligible. This simple implementation will probably be obsoleted
1182 // by the upcoming Clang-based coverage implementation.
1183 // By having it here and now we hope to
1184 // a) get the functionality to users earlier and
1185 // b) collect usage statistics to help improve Clang coverage design.
1186 bool AddressSanitizer::InjectCoverage(Function &F) {
1187  if (!ClCoverage) return false;
1189  Type *Int8Ty = IRB.getInt8Ty();
1190  GlobalVariable *Guard = new GlobalVariable(
1191  *F.getParent(), Int8Ty, false, GlobalValue::PrivateLinkage,
1192  Constant::getNullValue(Int8Ty), "__asan_gen_cov_" + F.getName());
1193  LoadInst *Load = IRB.CreateLoad(Guard);
1194  Load->setAtomic(Monotonic);
1195  Load->setAlignment(1);
1196  Value *Cmp = IRB.CreateICmpEQ(Constant::getNullValue(Int8Ty), Load);
1197  Instruction *Ins = SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), false);
1198  IRB.SetInsertPoint(Ins);
1199  // We pass &F to __sanitizer_cov. We could avoid this and rely on
1200  // GET_CALLER_PC, but having the PC of the first instruction is just nice.
1201  IRB.CreateCall(AsanCovFunction, IRB.CreatePointerCast(&F, IntptrTy));
1202  StoreInst *Store = IRB.CreateStore(ConstantInt::get(Int8Ty, 1), Guard);
1203  Store->setAtomic(Monotonic);
1204  Store->setAlignment(1);
1205  return true;
1206 }
1207 
1208 bool AddressSanitizer::runOnFunction(Function &F) {
1209  if (BL->isIn(F)) return false;
1210  if (&F == AsanCtorFunction) return false;
1211  if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
1212  DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
1213  initializeCallbacks(*F.getParent());
1214 
1215  // If needed, insert __asan_init before checking for SanitizeAddress attr.
1216  maybeInsertAsanInitAtFunctionEntry(F);
1217 
1219  return false;
1220 
1221  if (!ClDebugFunc.empty() && ClDebugFunc != F.getName())
1222  return false;
1223 
1224  // We want to instrument every address only once per basic block (unless there
1225  // are calls between uses).
1226  SmallSet<Value*, 16> TempsToInstrument;
1227  SmallVector<Instruction*, 16> ToInstrument;
1228  SmallVector<Instruction*, 8> NoReturnCalls;
1229  int NumAllocas = 0;
1230  bool IsWrite;
1231 
1232  // Fill the set of memory operations to instrument.
1233  for (Function::iterator FI = F.begin(), FE = F.end();
1234  FI != FE; ++FI) {
1235  TempsToInstrument.clear();
1236  int NumInsnsPerBB = 0;
1237  for (BasicBlock::iterator BI = FI->begin(), BE = FI->end();
1238  BI != BE; ++BI) {
1239  if (LooksLikeCodeInBug11395(BI)) return false;
1240  if (Value *Addr = isInterestingMemoryAccess(BI, &IsWrite)) {
1241  if (ClOpt && ClOptSameTemp) {
1242  if (!TempsToInstrument.insert(Addr))
1243  continue; // We've seen this temp in the current BB.
1244  }
1245  } else if (isa<MemIntrinsic>(BI) && ClMemIntrin) {
1246  // ok, take it.
1247  } else {
1248  if (isa<AllocaInst>(BI))
1249  NumAllocas++;
1250  CallSite CS(BI);
1251  if (CS) {
1252  // A call inside BB.
1253  TempsToInstrument.clear();
1254  if (CS.doesNotReturn())
1255  NoReturnCalls.push_back(CS.getInstruction());
1256  }
1257  continue;
1258  }
1259  ToInstrument.push_back(BI);
1260  NumInsnsPerBB++;
1261  if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB)
1262  break;
1263  }
1264  }
1265 
1266  Function *UninstrumentedDuplicate = 0;
1267  bool LikelyToInstrument =
1268  !NoReturnCalls.empty() || !ToInstrument.empty() || (NumAllocas > 0);
1269  if (ClKeepUninstrumented && LikelyToInstrument) {
1270  ValueToValueMapTy VMap;
1271  UninstrumentedDuplicate = CloneFunction(&F, VMap, false);
1272  UninstrumentedDuplicate->removeFnAttr(Attribute::SanitizeAddress);
1273  UninstrumentedDuplicate->setName("NOASAN_" + F.getName());
1274  F.getParent()->getFunctionList().push_back(UninstrumentedDuplicate);
1275  }
1276 
1277  // Instrument.
1278  int NumInstrumented = 0;
1279  for (size_t i = 0, n = ToInstrument.size(); i != n; i++) {
1280  Instruction *Inst = ToInstrument[i];
1281  if (ClDebugMin < 0 || ClDebugMax < 0 ||
1282  (NumInstrumented >= ClDebugMin && NumInstrumented <= ClDebugMax)) {
1283  if (isInterestingMemoryAccess(Inst, &IsWrite))
1284  instrumentMop(Inst);
1285  else
1286  instrumentMemIntrinsic(cast<MemIntrinsic>(Inst));
1287  }
1288  NumInstrumented++;
1289  }
1290 
1291  FunctionStackPoisoner FSP(F, *this);
1292  bool ChangedStack = FSP.runOnFunction();
1293 
1294  // We must unpoison the stack before every NoReturn call (throw, _exit, etc).
1295  // See e.g. http://code.google.com/p/address-sanitizer/issues/detail?id=37
1296  for (size_t i = 0, n = NoReturnCalls.size(); i != n; i++) {
1297  Instruction *CI = NoReturnCalls[i];
1298  IRBuilder<> IRB(CI);
1299  IRB.CreateCall(AsanHandleNoReturnFunc);
1300  }
1301 
1302  bool res = NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty();
1303 
1304  if (InjectCoverage(F))
1305  res = true;
1306 
1307  DEBUG(dbgs() << "ASAN done instrumenting: " << res << " " << F << "\n");
1308 
1309  if (ClKeepUninstrumented) {
1310  if (!res) {
1311  // No instrumentation is done, no need for the duplicate.
1312  if (UninstrumentedDuplicate)
1313  UninstrumentedDuplicate->eraseFromParent();
1314  } else {
1315  // The function was instrumented. We must have the duplicate.
1316  assert(UninstrumentedDuplicate);
1317  UninstrumentedDuplicate->setSection("NOASAN");
1318  assert(!F.hasSection());
1319  F.setSection("ASAN");
1320  }
1321  }
1322 
1323  return res;
1324 }
1325 
1326 static uint64_t ValueForPoison(uint64_t PoisonByte, size_t ShadowRedzoneSize) {
1327  if (ShadowRedzoneSize == 1) return PoisonByte;
1328  if (ShadowRedzoneSize == 2) return (PoisonByte << 8) + PoisonByte;
1329  if (ShadowRedzoneSize == 4)
1330  return (PoisonByte << 24) + (PoisonByte << 16) +
1331  (PoisonByte << 8) + (PoisonByte);
1332  llvm_unreachable("ShadowRedzoneSize is either 1, 2 or 4");
1333 }
1334 
1335 static void PoisonShadowPartialRightRedzone(uint8_t *Shadow,
1336  size_t Size,
1337  size_t RZSize,
1338  size_t ShadowGranularity,
1339  uint8_t Magic) {
1340  for (size_t i = 0; i < RZSize;
1341  i+= ShadowGranularity, Shadow++) {
1342  if (i + ShadowGranularity <= Size) {
1343  *Shadow = 0; // fully addressable
1344  } else if (i >= Size) {
1345  *Shadow = Magic; // unaddressable
1346  } else {
1347  *Shadow = Size - i; // first Size-i bytes are addressable
1348  }
1349  }
1350 }
1351 
1352 // Workaround for bug 11395: we don't want to instrument stack in functions
1353 // with large assembly blobs (32-bit only), otherwise reg alloc may crash.
1354 // FIXME: remove once the bug 11395 is fixed.
1355 bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
1356  if (LongSize != 32) return false;
1357  CallInst *CI = dyn_cast<CallInst>(I);
1358  if (!CI || !CI->isInlineAsm()) return false;
1359  if (CI->getNumArgOperands() <= 5) return false;
1360  // We have inline assembly with quite a few arguments.
1361  return true;
1362 }
1363 
1364 void FunctionStackPoisoner::initializeCallbacks(Module &M) {
1365  IRBuilder<> IRB(*C);
1366  for (int i = 0; i <= kMaxAsanStackMallocSizeClass; i++) {
1367  std::string Suffix = itostr(i);
1368  AsanStackMallocFunc[i] = checkInterfaceFunction(
1370  IntptrTy, IntptrTy, NULL));
1371  AsanStackFreeFunc[i] = checkInterfaceFunction(M.getOrInsertFunction(
1372  kAsanStackFreeNameTemplate + Suffix, IRB.getVoidTy(), IntptrTy,
1373  IntptrTy, IntptrTy, NULL));
1374  }
1375  AsanPoisonStackMemoryFunc = checkInterfaceFunction(M.getOrInsertFunction(
1376  kAsanPoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
1377  AsanUnpoisonStackMemoryFunc = checkInterfaceFunction(M.getOrInsertFunction(
1378  kAsanUnpoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
1379 }
1380 
1381 void FunctionStackPoisoner::poisonRedZones(
1382  const ArrayRef<AllocaInst*> &AllocaVec, IRBuilder<> &IRB, Value *ShadowBase,
1383  bool DoPoison) {
1384  size_t ShadowRZSize = RedzoneSize() >> Mapping.Scale;
1385  assert(ShadowRZSize >= 1 && ShadowRZSize <= 4);
1386  Type *RZTy = Type::getIntNTy(*C, ShadowRZSize * 8);
1387  Type *RZPtrTy = PointerType::get(RZTy, 0);
1388 
1389  Value *PoisonLeft = ConstantInt::get(RZTy,
1390  ValueForPoison(DoPoison ? kAsanStackLeftRedzoneMagic : 0LL, ShadowRZSize));
1391  Value *PoisonMid = ConstantInt::get(RZTy,
1392  ValueForPoison(DoPoison ? kAsanStackMidRedzoneMagic : 0LL, ShadowRZSize));
1393  Value *PoisonRight = ConstantInt::get(RZTy,
1394  ValueForPoison(DoPoison ? kAsanStackRightRedzoneMagic : 0LL, ShadowRZSize));
1395 
1396  // poison the first red zone.
1397  IRB.CreateStore(PoisonLeft, IRB.CreateIntToPtr(ShadowBase, RZPtrTy));
1398 
1399  // poison all other red zones.
1400  uint64_t Pos = RedzoneSize();
1401  for (size_t i = 0, n = AllocaVec.size(); i < n; i++) {
1402  AllocaInst *AI = AllocaVec[i];
1403  uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
1404  uint64_t AlignedSize = getAlignedAllocaSize(AI);
1405  assert(AlignedSize - SizeInBytes < RedzoneSize());
1406  Value *Ptr = NULL;
1407 
1408  Pos += AlignedSize;
1409 
1410  assert(ShadowBase->getType() == IntptrTy);
1411  if (SizeInBytes < AlignedSize) {
1412  // Poison the partial redzone at right
1413  Ptr = IRB.CreateAdd(
1414  ShadowBase, ConstantInt::get(IntptrTy,
1415  (Pos >> Mapping.Scale) - ShadowRZSize));
1416  size_t AddressableBytes = RedzoneSize() - (AlignedSize - SizeInBytes);
1417  uint32_t Poison = 0;
1418  if (DoPoison) {
1419  PoisonShadowPartialRightRedzone((uint8_t*)&Poison, AddressableBytes,
1420  RedzoneSize(),
1421  1ULL << Mapping.Scale,
1423  Poison =
1424  ASan.TD->isLittleEndian()
1425  ? support::endian::byte_swap<uint32_t, support::little>(Poison)
1426  : support::endian::byte_swap<uint32_t, support::big>(Poison);
1427  }
1428  Value *PartialPoison = ConstantInt::get(RZTy, Poison);
1429  IRB.CreateStore(PartialPoison, IRB.CreateIntToPtr(Ptr, RZPtrTy));
1430  }
1431 
1432  // Poison the full redzone at right.
1433  Ptr = IRB.CreateAdd(ShadowBase,
1434  ConstantInt::get(IntptrTy, Pos >> Mapping.Scale));
1435  bool LastAlloca = (i == AllocaVec.size() - 1);
1436  Value *Poison = LastAlloca ? PoisonRight : PoisonMid;
1437  IRB.CreateStore(Poison, IRB.CreateIntToPtr(Ptr, RZPtrTy));
1438 
1439  Pos += RedzoneSize();
1440  }
1441 }
1442 
1443 // Fake stack allocator (asan_fake_stack.h) has 11 size classes
1444 // for every power of 2 from kMinStackMallocSize to kMaxAsanStackMallocSizeClass
1445 static int StackMallocSizeClass(uint64_t LocalStackSize) {
1446  assert(LocalStackSize <= kMaxStackMallocSize);
1447  uint64_t MaxSize = kMinStackMallocSize;
1448  for (int i = 0; ; i++, MaxSize *= 2)
1449  if (LocalStackSize <= MaxSize)
1450  return i;
1451  llvm_unreachable("impossible LocalStackSize");
1452 }
1453 
1454 // Set Size bytes starting from ShadowBase to kAsanStackAfterReturnMagic.
1455 // We can not use MemSet intrinsic because it may end up calling the actual
1456 // memset. Size is a multiple of 8.
1457 // Currently this generates 8-byte stores on x86_64; it may be better to
1458 // generate wider stores.
1459 void FunctionStackPoisoner::SetShadowToStackAfterReturnInlined(
1460  IRBuilder<> &IRB, Value *ShadowBase, int Size) {
1461  assert(!(Size % 8));
1462  assert(kAsanStackAfterReturnMagic == 0xf5);
1463  for (int i = 0; i < Size; i += 8) {
1464  Value *p = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
1465  IRB.CreateStore(ConstantInt::get(IRB.getInt64Ty(), 0xf5f5f5f5f5f5f5f5ULL),
1466  IRB.CreateIntToPtr(p, IRB.getInt64Ty()->getPointerTo()));
1467  }
1468 }
1469 
1470 void FunctionStackPoisoner::poisonStack() {
1471  uint64_t LocalStackSize = TotalStackSize +
1472  (AllocaVec.size() + 1) * RedzoneSize();
1473 
1474  bool DoStackMalloc = ASan.CheckUseAfterReturn
1475  && LocalStackSize <= kMaxStackMallocSize;
1476  int StackMallocIdx = -1;
1477 
1478  assert(AllocaVec.size() > 0);
1479  Instruction *InsBefore = AllocaVec[0];
1480  IRBuilder<> IRB(InsBefore);
1481 
1482 
1483  Type *ByteArrayTy = ArrayType::get(IRB.getInt8Ty(), LocalStackSize);
1484  AllocaInst *MyAlloca =
1485  new AllocaInst(ByteArrayTy, "MyAlloca", InsBefore);
1486  if (ClRealignStack && StackAlignment < RedzoneSize())
1487  StackAlignment = RedzoneSize();
1488  MyAlloca->setAlignment(StackAlignment);
1489  assert(MyAlloca->isStaticAlloca());
1490  Value *OrigStackBase = IRB.CreatePointerCast(MyAlloca, IntptrTy);
1491  Value *LocalStackBase = OrigStackBase;
1492 
1493  if (DoStackMalloc) {
1494  // LocalStackBase = OrigStackBase
1495  // if (__asan_option_detect_stack_use_after_return)
1496  // LocalStackBase = __asan_stack_malloc_N(LocalStackBase, OrigStackBase);
1497  StackMallocIdx = StackMallocSizeClass(LocalStackSize);
1498  assert(StackMallocIdx <= kMaxAsanStackMallocSizeClass);
1499  Constant *OptionDetectUAR = F.getParent()->getOrInsertGlobal(
1501  Value *Cmp = IRB.CreateICmpNE(IRB.CreateLoad(OptionDetectUAR),
1503  Instruction *Term =
1504  SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), false);
1505  BasicBlock *CmpBlock = cast<Instruction>(Cmp)->getParent();
1506  IRBuilder<> IRBIf(Term);
1507  LocalStackBase = IRBIf.CreateCall2(
1508  AsanStackMallocFunc[StackMallocIdx],
1509  ConstantInt::get(IntptrTy, LocalStackSize), OrigStackBase);
1510  BasicBlock *SetBlock = cast<Instruction>(LocalStackBase)->getParent();
1511  IRB.SetInsertPoint(InsBefore);
1512  PHINode *Phi = IRB.CreatePHI(IntptrTy, 2);
1513  Phi->addIncoming(OrigStackBase, CmpBlock);
1514  Phi->addIncoming(LocalStackBase, SetBlock);
1515  LocalStackBase = Phi;
1516  }
1517 
1518  // This string will be parsed by the run-time (DescribeAddressIfStack).
1519  SmallString<2048> StackDescriptionStorage;
1520  raw_svector_ostream StackDescription(StackDescriptionStorage);
1521  StackDescription << AllocaVec.size() << " ";
1522 
1523  // Insert poison calls for lifetime intrinsics for alloca.
1524  bool HavePoisonedAllocas = false;
1525  for (size_t i = 0, n = AllocaPoisonCallVec.size(); i < n; i++) {
1526  const AllocaPoisonCall &APC = AllocaPoisonCallVec[i];
1527  assert(APC.InsBefore);
1528  assert(APC.AI);
1529  IRBuilder<> IRB(APC.InsBefore);
1530  poisonAlloca(APC.AI, APC.Size, IRB, APC.DoPoison);
1531  HavePoisonedAllocas |= APC.DoPoison;
1532  }
1533 
1534  uint64_t Pos = RedzoneSize();
1535  // Replace Alloca instructions with base+offset.
1536  for (size_t i = 0, n = AllocaVec.size(); i < n; i++) {
1537  AllocaInst *AI = AllocaVec[i];
1538  uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
1539  StringRef Name = AI->getName();
1540  StackDescription << Pos << " " << SizeInBytes << " "
1541  << Name.size() << " " << Name << " ";
1542  uint64_t AlignedSize = getAlignedAllocaSize(AI);
1543  assert((AlignedSize % RedzoneSize()) == 0);
1544  Value *NewAllocaPtr = IRB.CreateIntToPtr(
1545  IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Pos)),
1546  AI->getType());
1547  replaceDbgDeclareForAlloca(AI, NewAllocaPtr, DIB);
1548  AI->replaceAllUsesWith(NewAllocaPtr);
1549  Pos += AlignedSize + RedzoneSize();
1550  }
1551  assert(Pos == LocalStackSize);
1552 
1553  // The left-most redzone has enough space for at least 4 pointers.
1554  // Write the Magic value to redzone[0].
1555  Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
1557  BasePlus0);
1558  // Write the frame description constant to redzone[1].
1559  Value *BasePlus1 = IRB.CreateIntToPtr(
1560  IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, ASan.LongSize/8)),
1561  IntptrPtrTy);
1562  GlobalVariable *StackDescriptionGlobal =
1563  createPrivateGlobalForString(*F.getParent(), StackDescription.str());
1564  Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal,
1565  IntptrTy);
1566  IRB.CreateStore(Description, BasePlus1);
1567  // Write the PC to redzone[2].
1568  Value *BasePlus2 = IRB.CreateIntToPtr(
1569  IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy,
1570  2 * ASan.LongSize/8)),
1571  IntptrPtrTy);
1572  IRB.CreateStore(IRB.CreatePointerCast(&F, IntptrTy), BasePlus2);
1573 
1574  // Poison the stack redzones at the entry.
1575  Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
1576  poisonRedZones(AllocaVec, IRB, ShadowBase, true);
1577 
1578  // Unpoison the stack before all ret instructions.
1579  for (size_t i = 0, n = RetVec.size(); i < n; i++) {
1580  Instruction *Ret = RetVec[i];
1581  IRBuilder<> IRBRet(Ret);
1582  // Mark the current frame as retired.
1583  IRBRet.CreateStore(ConstantInt::get(IntptrTy, kRetiredStackFrameMagic),
1584  BasePlus0);
1585  // Unpoison the stack.
1586  poisonRedZones(AllocaVec, IRBRet, ShadowBase, false);
1587  if (DoStackMalloc) {
1588  assert(StackMallocIdx >= 0);
1589  // In use-after-return mode, mark the whole stack frame unaddressable.
1590  if (StackMallocIdx <= 4) {
1591  // For small sizes inline the whole thing:
1592  // if LocalStackBase != OrigStackBase:
1593  // memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
1594  // **SavedFlagPtr(LocalStackBase) = 0
1595  // FIXME: if LocalStackBase != OrigStackBase don't call poisonRedZones.
1596  Value *Cmp = IRBRet.CreateICmpNE(LocalStackBase, OrigStackBase);
1597  TerminatorInst *PoisonTerm =
1598  SplitBlockAndInsertIfThen(cast<Instruction>(Cmp), false);
1599  IRBuilder<> IRBPoison(PoisonTerm);
1600  int ClassSize = kMinStackMallocSize << StackMallocIdx;
1601  SetShadowToStackAfterReturnInlined(IRBPoison, ShadowBase,
1602  ClassSize >> Mapping.Scale);
1603  Value *SavedFlagPtrPtr = IRBPoison.CreateAdd(
1604  LocalStackBase,
1605  ConstantInt::get(IntptrTy, ClassSize - ASan.LongSize / 8));
1606  Value *SavedFlagPtr = IRBPoison.CreateLoad(
1607  IRBPoison.CreateIntToPtr(SavedFlagPtrPtr, IntptrPtrTy));
1608  IRBPoison.CreateStore(
1609  Constant::getNullValue(IRBPoison.getInt8Ty()),
1610  IRBPoison.CreateIntToPtr(SavedFlagPtr, IRBPoison.getInt8PtrTy()));
1611  } else {
1612  // For larger frames call __asan_stack_free_*.
1613  IRBRet.CreateCall3(AsanStackFreeFunc[StackMallocIdx], LocalStackBase,
1614  ConstantInt::get(IntptrTy, LocalStackSize),
1615  OrigStackBase);
1616  }
1617  } else if (HavePoisonedAllocas) {
1618  // If we poisoned some allocas in llvm.lifetime analysis,
1619  // unpoison whole stack frame now.
1620  assert(LocalStackBase == OrigStackBase);
1621  poisonAlloca(LocalStackBase, LocalStackSize, IRBRet, false);
1622  }
1623  }
1624 
1625  // We are done. Remove the old unused alloca instructions.
1626  for (size_t i = 0, n = AllocaVec.size(); i < n; i++)
1627  AllocaVec[i]->eraseFromParent();
1628 }
1629 
1630 void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
1631  IRBuilder<> &IRB, bool DoPoison) {
1632  // For now just insert the call to ASan runtime.
1633  Value *AddrArg = IRB.CreatePointerCast(V, IntptrTy);
1634  Value *SizeArg = ConstantInt::get(IntptrTy, Size);
1635  IRB.CreateCall2(DoPoison ? AsanPoisonStackMemoryFunc
1636  : AsanUnpoisonStackMemoryFunc,
1637  AddrArg, SizeArg);
1638 }
1639 
1640 // Handling llvm.lifetime intrinsics for a given %alloca:
1641 // (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
1642 // (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
1643 // invalid accesses) and unpoison it for llvm.lifetime.start (the memory
1644 // could be poisoned by previous llvm.lifetime.end instruction, as the
1645 // variable may go in and out of scope several times, e.g. in loops).
1646 // (3) if we poisoned at least one %alloca in a function,
1647 // unpoison the whole stack frame at function exit.
1648 
1649 AllocaInst *FunctionStackPoisoner::findAllocaForValue(Value *V) {
1650  if (AllocaInst *AI = dyn_cast<AllocaInst>(V))
1651  // We're intested only in allocas we can handle.
1652  return isInterestingAlloca(*AI) ? AI : 0;
1653  // See if we've already calculated (or started to calculate) alloca for a
1654  // given value.
1655  AllocaForValueMapTy::iterator I = AllocaForValue.find(V);
1656  if (I != AllocaForValue.end())
1657  return I->second;
1658  // Store 0 while we're calculating alloca for value V to avoid
1659  // infinite recursion if the value references itself.
1660  AllocaForValue[V] = 0;
1661  AllocaInst *Res = 0;
1662  if (CastInst *CI = dyn_cast<CastInst>(V))
1663  Res = findAllocaForValue(CI->getOperand(0));
1664  else if (PHINode *PN = dyn_cast<PHINode>(V)) {
1665  for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
1666  Value *IncValue = PN->getIncomingValue(i);
1667  // Allow self-referencing phi-nodes.
1668  if (IncValue == PN) continue;
1669  AllocaInst *IncValueAI = findAllocaForValue(IncValue);
1670  // AI for incoming values should exist and should all be equal.
1671  if (IncValueAI == 0 || (Res != 0 && IncValueAI != Res))
1672  return 0;
1673  Res = IncValueAI;
1674  }
1675  }
1676  if (Res != 0)
1677  AllocaForValue[V] = Res;
1678  return Res;
1679 }
Value * CreateLShr(Value *LHS, Value *RHS, const Twine &Name="", bool isExact=false)
Definition: IRBuilder.h:753
static cl::opt< bool > ClKeepUninstrumented("asan-keep-uninstrumented-functions", cl::desc("Keep uninstrumented copies of functions"), cl::Hidden, cl::init(false))
static cl::opt< std::string > ClDebugFunc("asan-debug-func", cl::Hidden, cl::desc("Debug func"))
static bool isValueValidForType(Type *Ty, uint64_t V)
Determine if the value is in range for the given type.
Definition: Constants.cpp:1159
static cl::opt< bool > ClStack("asan-stack", cl::desc("Handle stack memory"), cl::Hidden, cl::init(true))
LinkageTypes getLinkage() const
Definition: GlobalValue.h:218
void ReplaceInstWithInst(BasicBlock::InstListType &BIL, BasicBlock::iterator &BI, Instruction *I)
static Constant * getString(LLVMContext &Context, StringRef Initializer, bool AddNull=true)
Definition: Constants.cpp:2357
LoadInst * CreateLoad(Value *Ptr, const char *Name)
Definition: IRBuilder.h:879
void addIncoming(Value *V, BasicBlock *BB)
Base class for instruction visitors.
Definition: InstVisitor.h:81
static cl::opt< int > ClMappingScale("asan-mapping-scale", cl::desc("scale of asan shadow mapping"), cl::Hidden, cl::init(0))
size_t size() const
size - Get the string size.
Definition: StringRef.h:113
Value * CreateIntCast(Value *V, Type *DestTy, bool isSigned, const Twine &Name="")
Definition: IRBuilder.h:1180
The main container class for the LLVM Intermediate Representation.
Definition: Module.h:112
unsigned getAlignment() const
Definition: GlobalValue.h:79
iterator end()
Definition: Function.h:397
Intrinsic::ID getIntrinsicID() const
Definition: IntrinsicInst.h:43
static const int kAsanStackLeftRedzoneMagic
enable_if_c<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type dyn_cast(const Y &Val)
Definition: Casting.h:266
Available for inspection, not emission.
Definition: GlobalValue.h:35
unsigned getNumOperands() const
getNumOperands - Return number of MDNode operands.
Definition: Metadata.h:142
size_t find(char C, size_t From=0) const
Definition: StringRef.h:233
void appendToGlobalCtors(Module &M, Function *F, int Priority)
Definition: ModuleUtils.cpp:59
static Constant * getGetElementPtr(Constant *C, ArrayRef< Constant * > IdxList, bool InBounds=false)
Definition: Constants.h:1004
static const uintptr_t kCurrentStackFrameMagic
static PointerType * get(Type *ElementType, unsigned AddressSpace)
Definition: Type.cpp:730
Value * CreatePointerCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1172
Like Internal, but omit from symbol table.
Definition: GlobalValue.h:42
static SpecialCaseList * createOrDie(const StringRef Path)
Externally visible function.
Definition: GlobalValue.h:34
uint64_t getLimitedValue(uint64_t Limit=~0ULL) const
Definition: APInt.h:408
static const char *const kAsanMappingScaleName
static cl::opt< int > ClDebug("asan-debug", cl::desc("debug"), cl::Hidden, cl::init(0))
void setSection(StringRef S)
Definition: GlobalValue.h:97
const Function * getParent() const
Return the enclosing method, or null if none.
Definition: BasicBlock.h:116
static const int kAsanStackPartialRedzoneMagic
MDNode - a tuple of other values.
Definition: Metadata.h:69
F(f)
Value * CreateICmpEQ(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1206
const Constant * getInitializer() const
const std::string & getTargetTriple() const
Definition: Module.h:237
void setDebugLoc(const DebugLoc &Loc)
setDebugLoc - Set the debug location information for this instruction.
Definition: Instruction.h:175
bool isMinusOne() const
Determine if the value is all ones.
Definition: Constants.h:176
static const char *const kAsanMappingOffsetName
Value * CreateSub(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:637
LoopInfoBase< BlockT, LoopT > * LI
Definition: LoopInfoImpl.h:411
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const char *reason, bool gen_crash_diag=true)
static Constant * getNullValue(Type *Ty)
Definition: Constants.cpp:111
StringRef getName() const
Definition: Value.cpp:167
Value * getOperand(unsigned i) const LLVM_READONLY
getOperand - Return specified operand.
Definition: Metadata.cpp:307
IntegerType * getInt32Ty()
Fetch the type representing a 32-bit integer.
Definition: IRBuilder.h:310
bool isArrayAllocation() const
static const uint64_t kDefaultShadowScale
PHINode * CreatePHI(Type *Ty, unsigned NumReservedValues, const Twine &Name="")
Definition: IRBuilder.h:1299
static bool GlobalWasGeneratedByAsan(GlobalVariable *G)
void push_back(NodeTy *val)
Definition: ilist.h:554
void dump() const
dump - Support for debugging, callable in GDB: V->dump()
Definition: AsmWriter.cpp:2212
IntegerType * getInt64Ty()
Fetch the type representing a 64-bit integer.
Definition: IRBuilder.h:315
Base class of casting instructions.
Definition: InstrTypes.h:387
const APInt & getValue() const
Return the constant's value.
Definition: Constants.h:105
bool hasSection() const
Definition: GlobalValue.h:95
bool isThreadLocal() const
If the value is "Thread Local", its value isn't shared by the threads.
#define llvm_unreachable(msg)
Value * CreateIntToPtr(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1128
static cl::opt< int > ClDebugMax("asan-debug-max", cl::desc("Debug man inst"), cl::Hidden, cl::init(-1))
unsigned getNumArgOperands() const
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
Definition: IRBuilder.h:421
static BranchInst * Create(BasicBlock *IfTrue, Instruction *InsertBefore=0)
Type * getAllocatedType() const
void setName(const Twine &Name)
Definition: Value.cpp:175
static const char *const kAsanModuleCtorName
ID
LLVM Calling Convention Representation.
Definition: CallingConv.h:26
const std::string & getModuleIdentifier() const
Definition: Module.h:228
#define G(x, y, z)
Definition: MD5.cpp:52
Type * getVoidTy()
Fetch the type representing void.
Definition: IRBuilder.h:330
static cl::opt< bool > ClInitializers("asan-initialization-order", cl::desc("Handle C++ initializer order"), cl::Hidden, cl::init(false))
bool replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress, DIBuilder &Builder)
Definition: Local.cpp:1083
global_iterator global_begin()
Definition: Module.h:521
static cl::opt< std::string > ClBlacklistFile("asan-blacklist", cl::desc("File containing the list of objects to ignore ""during instrumentation"), cl::Hidden)
static const char *const kAsanPoisonStackMemoryName
void setAtomic(AtomicOrdering Ordering, SynchronizationScope SynchScope=CrossThread)
Definition: Instructions.h:212
Value * CreateAnd(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:789
void clear()
Definition: SmallSet.h:97
Value * CreateOr(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:805
bool LLVM_ATTRIBUTE_UNUSED_RESULT empty() const
Definition: SmallVector.h:56
enable_if_c< std::numeric_limits< T >::is_integer &&!std::numeric_limits< T >::is_signed, std::size_t >::type countTrailingZeros(T Val, ZeroBehavior ZB=ZB_Width)
Count number of 0's from the least significant bit to the most stopping at the first 1...
Definition: MathExtras.h:49
static const int kMaxAsanStackMallocSizeClass
static cl::opt< bool > ClOptSameTemp("asan-opt-same-temp", cl::desc("Instrument the same temp just once"), cl::Hidden, cl::init(true))
static FunctionType * get(Type *Result, ArrayRef< Type * > Params, bool isVarArg)
Definition: Type.cpp:361
static cl::opt< bool > ClOpt("asan-opt", cl::desc("Optimize instrumentation"), cl::Hidden, cl::init(true))
ModulePass * createAddressSanitizerModulePass(bool CheckInitOrder=true, StringRef BlacklistFile=StringRef(), bool ZeroBaseShadow=false)
static cl::opt< bool > ClCoverage("asan-coverage", cl::desc("ASan coverage"), cl::Hidden, cl::init(false))
bool insert(const T &V)
Definition: SmallSet.h:59
void replaceAllUsesWith(Value *V)
Definition: Value.cpp:303
void takeName(Value *V)
Definition: Value.cpp:239
iterator begin()
Definition: Function.h:395
static cl::opt< bool > ClAlwaysSlowPath("asan-always-slow-path", cl::desc("use instrumentation with slow path for all accesses"), cl::Hidden, cl::init(false))
StoreInst * CreateStore(Value *Val, Value *Ptr, bool isVolatile=false)
Definition: IRBuilder.h:888
Type * getElementType() const
Definition: DerivedTypes.h:319
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:109
void SetInsertPoint(BasicBlock *TheBB)
This specifies that created instructions should be appended to the end of the specified block...
Definition: IRBuilder.h:83
static const uint64_t kDefaultShadowOffset32
Function * getFunction(StringRef Name) const
Definition: Module.cpp:221
static cl::opt< bool > ClInstrumentWrites("asan-instrument-writes", cl::desc("instrument write instructions"), cl::Hidden, cl::init(true))
static const size_t kNumberOfAccessSizes
Same, but only replaced by something equivalent.
Definition: GlobalValue.h:37
initializer< Ty > init(const Ty &Val)
Definition: CommandLine.h:314
* if(!EatIfPresent(lltok::kw_thread_local)) return false
static cl::opt< bool > ClUseAfterReturn("asan-use-after-return", cl::desc("Check return-after-free"), cl::Hidden, cl::init(false))
Value * CreateICmpSGE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1227
Constant * getOrInsertFunction(StringRef Name, FunctionType *T, AttributeSet AttributeList)
Definition: Module.cpp:138
LLVM Basic Block Representation.
Definition: BasicBlock.h:72
TerminatorInst * SplitBlockAndInsertIfThen(Instruction *Cmp, bool Unreachable, MDNode *BranchWeights=0)
static cl::opt< bool > ClMemIntrin("asan-memintrin", cl::desc("Handle memset/memcpy/memmove"), cl::Hidden, cl::init(true))
BasicBlock * getSuccessor(unsigned idx) const
Definition: InstrTypes.h:65
Constant * getOrInsertGlobal(StringRef Name, Type *Ty)
Definition: Module.cpp:250
df_iterator< T > df_end(const T &G)
Value * CreateAdd(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:615
static const size_t kMinStackMallocSize
LLVM Constant Representation.
Definition: Constant.h:41
PointerType * getType() const
Definition: Instructions.h:91
static const char *const kAsanReportStoreN
static const char *const kAsanInitName
static const char *const kAsanStackFreeNameTemplate
static const uint64_t kMIPS32_ShadowOffset32
static Constant * get(ArrayType *T, ArrayRef< Constant * > V)
Definition: Constants.cpp:745
unsigned getAlignment() const
Definition: Instructions.h:103
static Function * checkInterfaceFunction(Constant *FuncOrBitcast)
const DebugLoc & getDebugLoc() const
getDebugLoc - Return the debug location for this node as a DebugLoc.
Definition: Instruction.h:178
static cl::opt< bool > ClInstrumentReads("asan-instrument-reads", cl::desc("instrument read instructions"), cl::Hidden, cl::init(true))
static Type * getVoidTy(LLVMContext &C)
Definition: Type.cpp:227
static const int kAsanStackAfterReturnMagic
MDNode * getOperand(unsigned i) const
getOperand - Return specified operand.
Definition: Metadata.cpp:545
Value * getOperand(unsigned i) const
Definition: User.h:88
static cl::opt< bool > ClOptGlobals("asan-opt-globals", cl::desc("Don't instrument scalar globals"), cl::Hidden, cl::init(true))
static const uintptr_t kRetiredStackFrameMagic
static Constant * get(StructType *T, ArrayRef< Constant * > V)
Definition: Constants.cpp:874
static cl::opt< bool > ClRealignStack("asan-realign-stack", cl::desc("Realign stack to 32"), cl::Hidden, cl::init(true))
static const char *const kAsanGenPrefix
const std::string & getSection() const
Definition: GlobalValue.h:96
static cl::opt< int > ClMaxInsnsToInstrumentPerBB("asan-max-ins-per-bb", cl::init(10000), cl::desc("maximal number of instructions to instrument in any given BB"), cl::Hidden)
static std::string itostr(int64_t X)
Definition: StringExtras.h:104
static cl::opt< bool > ClGlobals("asan-globals", cl::desc("Handle global objects"), cl::Hidden, cl::init(true))
void setAtomic(AtomicOrdering Ordering, SynchronizationScope SynchScope=CrossThread)
Definition: Instructions.h:332
PointerType * getPointerTo(unsigned AddrSpace=0)
Definition: Type.cpp:756
void appendToGlobalDtors(Module &M, Function *F, int Priority)
Same as appendToGlobalCtors(), but for global dtors.
Definition: ModuleUtils.cpp:63
static const char *const kAsanRegisterGlobalsName
static const char *const Magic
Definition: Archive.cpp:24
static CallInst * Create(Value *Func, ArrayRef< Value * > Args, const Twine &NameStr="", Instruction *InsertBefore=0)
global_iterator global_end()
Definition: Module.h:523
const FunctionListType & getFunctionList() const
Get the Module's list of functions (constant).
Definition: Module.h:492
static Constant * getPointerCast(Constant *C, Type *Ty)
Create a BitCast or a PtrToInt cast constant expression.
Definition: Constants.cpp:1487
static IntegerType * get(LLVMContext &C, unsigned NumBits)
Get or create an IntegerType instance.
Definition: Type.cpp:305
See the file comment.
Definition: ValueMap.h:75
Class for constant integers.
Definition: Constants.h:51
static const char *const kAsanStackMallocNameTemplate
static const char *const kAsanUnpoisonStackMemoryName
static StructType * get(LLVMContext &Context, ArrayRef< Type * > Elements, bool isPacked=false)
Definition: Type.cpp:405
Value * getDest() const
void setAlignment(unsigned Align)
Definition: Globals.cpp:58
static size_t TypeSizeToSizeIndex(uint32_t TypeSize)
bool isStaticAlloca() const
Type * getType() const
Definition: Value.h:111
void copyAttributesFrom(const GlobalValue *Src)
Definition: Globals.cpp:183
void setUnnamedAddr(bool Val)
Definition: GlobalValue.h:85
static const uint64_t kDefaultShadowOffset64
Value * getLength() const
ConstantInt * getInt32(uint32_t C)
Get a constant 32-bit value.
Definition: IRBuilder.h:276
static IntegerType * getIntNTy(LLVMContext &C, unsigned N)
Definition: Type.cpp:244
static cl::opt< int > ClDebugStack("asan-debug-stack", cl::desc("debug stack"), cl::Hidden, cl::init(0))
static Constant * get(Type *Ty, uint64_t V, bool isSigned=false)
Definition: Constants.cpp:492
const BasicBlock & getEntryBlock() const
Definition: Function.h:380
bool isNullValue() const
Definition: Constants.cpp:75
raw_ostream & dbgs()
dbgs - Return a circular-buffered debug stream.
Definition: Debug.cpp:101
df_iterator< T > df_begin(const T &G)
Value * getArgOperand(unsigned i) const
static cl::opt< bool > ClShort64BitOffset("asan-short-64bit-mapping-offset", cl::desc("Use short immediate constant as the mapping offset for 64bit"), cl::Hidden, cl::init(true))
static const char *const kAsanReportLoadN
bool hasInitializer() const
LinkageTypes
An enumeration for the kinds of linkage for global values.
Definition: GlobalValue.h:33
bool isConstant() const
static cl::opt< bool > ClCheckLifetime("asan-check-lifetime", cl::desc("Use llvm.lifetime intrinsics to insert extra checks"), cl::Hidden, cl::init(false))
IntegerType * getInt8Ty()
Fetch the type representing an 8-bit integer.
Definition: IRBuilder.h:300
static const int kAsanStackMidRedzoneMagic
static const int kAsanStackRightRedzoneMagic
bool isInlineAsm() const
isInlineAsm - Check if this call is an inline asm statement.
FunctionPass * createAddressSanitizerFunctionPass(bool CheckInitOrder=true, bool CheckUseAfterReturn=false, bool CheckLifetime=false, StringRef BlacklistFile=StringRef(), bool ZeroBaseShadow=false)
static const uint64_t kDefaultShort64bitShadowOffset
bool isGEPWithNoNotionalOverIndexing() const
Return true if this is a getelementptr expression and all the index operands are compile-time known i...
Definition: Constants.cpp:1044
STATISTIC(NumInstrumentedReads,"Number of instrumented reads")
Value * getSource() const
PointerType * getType() const
getType - Global values are always pointers.
Definition: GlobalValue.h:107
static cl::opt< int > ClDebugMin("asan-debug-min", cl::desc("Debug min inst"), cl::Hidden, cl::init(-1))
NamedMDNode * getNamedMetadata(const Twine &Name) const
Definition: Module.cpp:286
bool hasFnAttribute(Attribute::AttrKind Kind) const
Return true if the function has the attribute.
Definition: Function.h:200
static int StackMallocSizeClass(uint64_t LocalStackSize)
void removeFnAttr(Attribute::AttrKind N)
Remove function attributes from this function.
Definition: Function.h:182
static GlobalVariable * createPrivateGlobalForString(Module &M, StringRef Str)
AddressSanitizer is on.
Definition: Attributes.h:106
#define I(x, y, z)
Definition: MD5.cpp:54
TerminatorInst * getTerminator()
Returns the terminator instruction if the block is well formed or null if the block is not well forme...
Definition: BasicBlock.cpp:120
static Value * isInterestingMemoryAccess(Instruction *I, bool *IsWrite)
Function * CloneFunction(const Function *F, ValueToValueMapTy &VMap, bool ModuleLevelChanges, ClonedCodeInfo *CodeInfo=0)
static BasicBlock * Create(LLVMContext &Context, const Twine &Name="", Function *Parent=0, BasicBlock *InsertBefore=0)
Creates a new BasicBlock.
Definition: BasicBlock.h:109
static ArrayType * get(Type *ElementType, uint64_t NumElements)
Definition: Type.cpp:679
INITIALIZE_PASS(AddressSanitizer,"asan","AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false, false) FunctionPass *llvm
Rename collisions when linking (static functions).
Definition: GlobalValue.h:41
static const char *const kAsanOptionDetectUAR
Value * CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1209
virtual void eraseFromParent()
Definition: Function.cpp:187
static InlineAsm * get(FunctionType *Ty, StringRef AsmString, StringRef Constraints, bool hasSideEffects, bool isAlignStack=false, AsmDialect asmDialect=AD_ATT)
Definition: InlineAsm.cpp:28
static ReturnInst * Create(LLVMContext &C, Value *retVal=0, Instruction *InsertBefore=0)
static const char *const kAsanModuleDtorName
static void PoisonShadowPartialRightRedzone(uint8_t *Shadow, size_t Size, size_t RZSize, size_t ShadowGranularity, uint8_t Magic)
EnvironmentType getEnvironment() const
getEnvironment - Get the parsed environment type of this triple.
Definition: Triple.h:187
static const char *const kAsanUnregisterGlobalsName
static const char *const kAsanUnpoisonGlobalsName
CallInst * CreateCall2(Value *Callee, Value *Arg1, Value *Arg2, const Twine &Name="")
Definition: IRBuilder.h:1310
static const char *const kAsanPoisonGlobalsName
Module * getParent()
Definition: GlobalValue.h:286
LLVM Value Representation.
Definition: Value.h:66
void setAlignment(unsigned Align)
static const uint64_t kPPC64_ShadowOffset64
CallInst * CreateCall(Value *Callee, const Twine &Name="")
Definition: IRBuilder.h:1304
static cl::opt< bool > ClInstrumentAtomics("asan-instrument-atomics", cl::desc("instrument atomic instructions (rmw, cmpxchg)"), cl::Hidden, cl::init(true))
static const Function * getParent(const Value *V)
bool isSized() const
Definition: Type.h:278
unsigned getNumOperands() const
getNumOperands - Return the number of NamedMDNode operands.
Definition: Metadata.cpp:540
#define DEBUG(X)
Definition: Debug.h:97
static const char *const kAsanHandleNoReturnName
static const size_t kMaxStackMallocSize
static cl::opt< int > ClMappingOffsetLog("asan-mapping-offset-log", cl::desc("offset of asan shadow mapping"), cl::Hidden, cl::init(-1))
iterator getFirstInsertionPt()
Returns an iterator to the first instruction in this block that is suitable for inserting a non-PHI i...
Definition: BasicBlock.cpp:170
INITIALIZE_PASS(GlobalMerge,"global-merge","Global Merge", false, false) bool GlobalMerge const DataLayout * TD
static const int kAsanCtorAndCtorPriority
LLVMContext & getContext() const
Definition: Module.h:249
static const char *const kAsanCovName
static Function * Create(FunctionType *Ty, LinkageTypes Linkage, const Twine &N="", Module *M=0)
Definition: Function.h:128
static uint64_t ValueForPoison(uint64_t PoisonByte, size_t ShadowRedzoneSize)
static const char *const kAsanReportErrorTemplate