LLVM  8.0.0svn
AddressSanitizer.cpp
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1 //===- AddressSanitizer.cpp - memory error detector -----------------------===//
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 // https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/SmallPtrSet.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/ADT/StringExtras.h"
23 #include "llvm/ADT/StringRef.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/ADT/Twine.h"
31 #include "llvm/IR/Argument.h"
32 #include "llvm/IR/Attributes.h"
33 #include "llvm/IR/BasicBlock.h"
34 #include "llvm/IR/CallSite.h"
35 #include "llvm/IR/Comdat.h"
36 #include "llvm/IR/Constant.h"
37 #include "llvm/IR/Constants.h"
38 #include "llvm/IR/DIBuilder.h"
39 #include "llvm/IR/DataLayout.h"
41 #include "llvm/IR/DebugLoc.h"
42 #include "llvm/IR/DerivedTypes.h"
43 #include "llvm/IR/Dominators.h"
44 #include "llvm/IR/Function.h"
45 #include "llvm/IR/GlobalAlias.h"
46 #include "llvm/IR/GlobalValue.h"
47 #include "llvm/IR/GlobalVariable.h"
48 #include "llvm/IR/IRBuilder.h"
49 #include "llvm/IR/InlineAsm.h"
50 #include "llvm/IR/InstVisitor.h"
51 #include "llvm/IR/InstrTypes.h"
52 #include "llvm/IR/Instruction.h"
53 #include "llvm/IR/Instructions.h"
54 #include "llvm/IR/IntrinsicInst.h"
55 #include "llvm/IR/Intrinsics.h"
56 #include "llvm/IR/LLVMContext.h"
57 #include "llvm/IR/MDBuilder.h"
58 #include "llvm/IR/Metadata.h"
59 #include "llvm/IR/Module.h"
60 #include "llvm/IR/Type.h"
61 #include "llvm/IR/Use.h"
62 #include "llvm/IR/Value.h"
63 #include "llvm/MC/MCSectionMachO.h"
64 #include "llvm/Pass.h"
65 #include "llvm/Support/Casting.h"
67 #include "llvm/Support/Debug.h"
77 #include <algorithm>
78 #include <cassert>
79 #include <cstddef>
80 #include <cstdint>
81 #include <iomanip>
82 #include <limits>
83 #include <memory>
84 #include <sstream>
85 #include <string>
86 #include <tuple>
87 
88 using namespace llvm;
89 
90 #define DEBUG_TYPE "asan"
91 
92 static const uint64_t kDefaultShadowScale = 3;
93 static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
94 static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
95 static const uint64_t kDynamicShadowSentinel =
97 static const uint64_t kIOSShadowOffset32 = 1ULL << 30;
98 static const uint64_t kIOSSimShadowOffset32 = 1ULL << 30;
100 static const uint64_t kSmallX86_64ShadowOffsetBase = 0x7FFFFFFF; // < 2G.
101 static const uint64_t kSmallX86_64ShadowOffsetAlignMask = ~0xFFFULL;
102 static const uint64_t kLinuxKasan_ShadowOffset64 = 0xdffffc0000000000;
103 static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 44;
104 static const uint64_t kSystemZ_ShadowOffset64 = 1ULL << 52;
105 static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa0000;
106 static const uint64_t kMIPS64_ShadowOffset64 = 1ULL << 37;
107 static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 36;
108 static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
109 static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
110 static const uint64_t kNetBSD_ShadowOffset32 = 1ULL << 30;
111 static const uint64_t kNetBSD_ShadowOffset64 = 1ULL << 46;
112 static const uint64_t kPS4CPU_ShadowOffset64 = 1ULL << 40;
113 static const uint64_t kWindowsShadowOffset32 = 3ULL << 28;
114 
115 static const uint64_t kMyriadShadowScale = 5;
116 static const uint64_t kMyriadMemoryOffset32 = 0x80000000ULL;
117 static const uint64_t kMyriadMemorySize32 = 0x20000000ULL;
118 static const uint64_t kMyriadTagShift = 29;
119 static const uint64_t kMyriadDDRTag = 4;
120 static const uint64_t kMyriadCacheBitMask32 = 0x40000000ULL;
121 
122 // The shadow memory space is dynamically allocated.
124 
125 static const size_t kMinStackMallocSize = 1 << 6; // 64B
126 static const size_t kMaxStackMallocSize = 1 << 16; // 64K
127 static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
128 static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;
129 
130 static const char *const kAsanModuleCtorName = "asan.module_ctor";
131 static const char *const kAsanModuleDtorName = "asan.module_dtor";
132 static const uint64_t kAsanCtorAndDtorPriority = 1;
133 static const char *const kAsanReportErrorTemplate = "__asan_report_";
134 static const char *const kAsanRegisterGlobalsName = "__asan_register_globals";
135 static const char *const kAsanUnregisterGlobalsName =
136  "__asan_unregister_globals";
137 static const char *const kAsanRegisterImageGlobalsName =
138  "__asan_register_image_globals";
139 static const char *const kAsanUnregisterImageGlobalsName =
140  "__asan_unregister_image_globals";
141 static const char *const kAsanRegisterElfGlobalsName =
142  "__asan_register_elf_globals";
143 static const char *const kAsanUnregisterElfGlobalsName =
144  "__asan_unregister_elf_globals";
145 static const char *const kAsanPoisonGlobalsName = "__asan_before_dynamic_init";
146 static const char *const kAsanUnpoisonGlobalsName = "__asan_after_dynamic_init";
147 static const char *const kAsanInitName = "__asan_init";
148 static const char *const kAsanVersionCheckNamePrefix =
149  "__asan_version_mismatch_check_v";
150 static const char *const kAsanPtrCmp = "__sanitizer_ptr_cmp";
151 static const char *const kAsanPtrSub = "__sanitizer_ptr_sub";
152 static const char *const kAsanHandleNoReturnName = "__asan_handle_no_return";
153 static const int kMaxAsanStackMallocSizeClass = 10;
154 static const char *const kAsanStackMallocNameTemplate = "__asan_stack_malloc_";
155 static const char *const kAsanStackFreeNameTemplate = "__asan_stack_free_";
156 static const char *const kAsanGenPrefix = "___asan_gen_";
157 static const char *const kODRGenPrefix = "__odr_asan_gen_";
158 static const char *const kSanCovGenPrefix = "__sancov_gen_";
159 static const char *const kAsanSetShadowPrefix = "__asan_set_shadow_";
160 static const char *const kAsanPoisonStackMemoryName =
161  "__asan_poison_stack_memory";
162 static const char *const kAsanUnpoisonStackMemoryName =
163  "__asan_unpoison_stack_memory";
164 
165 // ASan version script has __asan_* wildcard. Triple underscore prevents a
166 // linker (gold) warning about attempting to export a local symbol.
167 static const char *const kAsanGlobalsRegisteredFlagName =
168  "___asan_globals_registered";
169 
170 static const char *const kAsanOptionDetectUseAfterReturn =
171  "__asan_option_detect_stack_use_after_return";
172 
173 static const char *const kAsanShadowMemoryDynamicAddress =
174  "__asan_shadow_memory_dynamic_address";
175 
176 static const char *const kAsanAllocaPoison = "__asan_alloca_poison";
177 static const char *const kAsanAllocasUnpoison = "__asan_allocas_unpoison";
178 
179 // Accesses sizes are powers of two: 1, 2, 4, 8, 16.
180 static const size_t kNumberOfAccessSizes = 5;
181 
182 static const unsigned kAllocaRzSize = 32;
183 
184 // Command-line flags.
185 
187  "asan-kernel", cl::desc("Enable KernelAddressSanitizer instrumentation"),
188  cl::Hidden, cl::init(false));
189 
190 static cl::opt<bool> ClRecover(
191  "asan-recover",
192  cl::desc("Enable recovery mode (continue-after-error)."),
193  cl::Hidden, cl::init(false));
194 
195 // This flag may need to be replaced with -f[no-]asan-reads.
196 static cl::opt<bool> ClInstrumentReads("asan-instrument-reads",
197  cl::desc("instrument read instructions"),
198  cl::Hidden, cl::init(true));
199 
201  "asan-instrument-writes", cl::desc("instrument write instructions"),
202  cl::Hidden, cl::init(true));
203 
205  "asan-instrument-atomics",
206  cl::desc("instrument atomic instructions (rmw, cmpxchg)"), cl::Hidden,
207  cl::init(true));
208 
210  "asan-always-slow-path",
211  cl::desc("use instrumentation with slow path for all accesses"), cl::Hidden,
212  cl::init(false));
213 
215  "asan-force-dynamic-shadow",
216  cl::desc("Load shadow address into a local variable for each function"),
217  cl::Hidden, cl::init(false));
218 
219 static cl::opt<bool>
220  ClWithIfunc("asan-with-ifunc",
221  cl::desc("Access dynamic shadow through an ifunc global on "
222  "platforms that support this"),
223  cl::Hidden, cl::init(true));
224 
226  "asan-with-ifunc-suppress-remat",
227  cl::desc("Suppress rematerialization of dynamic shadow address by passing "
228  "it through inline asm in prologue."),
229  cl::Hidden, cl::init(true));
230 
231 // This flag limits the number of instructions to be instrumented
232 // in any given BB. Normally, this should be set to unlimited (INT_MAX),
233 // but due to http://llvm.org/bugs/show_bug.cgi?id=12652 we temporary
234 // set it to 10000.
236  "asan-max-ins-per-bb", cl::init(10000),
237  cl::desc("maximal number of instructions to instrument in any given BB"),
238  cl::Hidden);
239 
240 // This flag may need to be replaced with -f[no]asan-stack.
241 static cl::opt<bool> ClStack("asan-stack", cl::desc("Handle stack memory"),
242  cl::Hidden, cl::init(true));
244  "asan-max-inline-poisoning-size",
245  cl::desc(
246  "Inline shadow poisoning for blocks up to the given size in bytes."),
247  cl::Hidden, cl::init(64));
248 
249 static cl::opt<bool> ClUseAfterReturn("asan-use-after-return",
250  cl::desc("Check stack-use-after-return"),
251  cl::Hidden, cl::init(true));
252 
253 static cl::opt<bool> ClRedzoneByvalArgs("asan-redzone-byval-args",
254  cl::desc("Create redzones for byval "
255  "arguments (extra copy "
256  "required)"), cl::Hidden,
257  cl::init(true));
258 
259 static cl::opt<bool> ClUseAfterScope("asan-use-after-scope",
260  cl::desc("Check stack-use-after-scope"),
261  cl::Hidden, cl::init(false));
262 
263 // This flag may need to be replaced with -f[no]asan-globals.
264 static cl::opt<bool> ClGlobals("asan-globals",
265  cl::desc("Handle global objects"), cl::Hidden,
266  cl::init(true));
267 
268 static cl::opt<bool> ClInitializers("asan-initialization-order",
269  cl::desc("Handle C++ initializer order"),
270  cl::Hidden, cl::init(true));
271 
273  "asan-detect-invalid-pointer-pair",
274  cl::desc("Instrument <, <=, >, >=, - with pointer operands"), cl::Hidden,
275  cl::init(false));
276 
278  "asan-realign-stack",
279  cl::desc("Realign stack to the value of this flag (power of two)"),
280  cl::Hidden, cl::init(32));
281 
283  "asan-instrumentation-with-call-threshold",
284  cl::desc(
285  "If the function being instrumented contains more than "
286  "this number of memory accesses, use callbacks instead of "
287  "inline checks (-1 means never use callbacks)."),
288  cl::Hidden, cl::init(7000));
289 
291  "asan-memory-access-callback-prefix",
292  cl::desc("Prefix for memory access callbacks"), cl::Hidden,
293  cl::init("__asan_"));
294 
295 static cl::opt<bool>
296  ClInstrumentDynamicAllocas("asan-instrument-dynamic-allocas",
297  cl::desc("instrument dynamic allocas"),
298  cl::Hidden, cl::init(true));
299 
301  "asan-skip-promotable-allocas",
302  cl::desc("Do not instrument promotable allocas"), cl::Hidden,
303  cl::init(true));
304 
305 // These flags allow to change the shadow mapping.
306 // The shadow mapping looks like
307 // Shadow = (Mem >> scale) + offset
308 
309 static cl::opt<int> ClMappingScale("asan-mapping-scale",
310  cl::desc("scale of asan shadow mapping"),
311  cl::Hidden, cl::init(0));
312 
314  "asan-mapping-offset",
315  cl::desc("offset of asan shadow mapping [EXPERIMENTAL]"), cl::Hidden,
316  cl::init(0));
317 
318 // Optimization flags. Not user visible, used mostly for testing
319 // and benchmarking the tool.
320 
321 static cl::opt<bool> ClOpt("asan-opt", cl::desc("Optimize instrumentation"),
322  cl::Hidden, cl::init(true));
323 
325  "asan-opt-same-temp", cl::desc("Instrument the same temp just once"),
326  cl::Hidden, cl::init(true));
327 
328 static cl::opt<bool> ClOptGlobals("asan-opt-globals",
329  cl::desc("Don't instrument scalar globals"),
330  cl::Hidden, cl::init(true));
331 
333  "asan-opt-stack", cl::desc("Don't instrument scalar stack variables"),
334  cl::Hidden, cl::init(false));
335 
337  "asan-stack-dynamic-alloca",
338  cl::desc("Use dynamic alloca to represent stack variables"), cl::Hidden,
339  cl::init(true));
340 
342  "asan-force-experiment",
343  cl::desc("Force optimization experiment (for testing)"), cl::Hidden,
344  cl::init(0));
345 
346 static cl::opt<bool>
347  ClUsePrivateAliasForGlobals("asan-use-private-alias",
348  cl::desc("Use private aliases for global"
349  " variables"),
350  cl::Hidden, cl::init(false));
351 
352 static cl::opt<bool>
353  ClUseGlobalsGC("asan-globals-live-support",
354  cl::desc("Use linker features to support dead "
355  "code stripping of globals"),
356  cl::Hidden, cl::init(true));
357 
358 // This is on by default even though there is a bug in gold:
359 // https://sourceware.org/bugzilla/show_bug.cgi?id=19002
360 static cl::opt<bool>
361  ClWithComdat("asan-with-comdat",
362  cl::desc("Place ASan constructors in comdat sections"),
363  cl::Hidden, cl::init(true));
364 
365 // Debug flags.
366 
367 static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
368  cl::init(0));
369 
370 static cl::opt<int> ClDebugStack("asan-debug-stack", cl::desc("debug stack"),
371  cl::Hidden, cl::init(0));
372 
373 static cl::opt<std::string> ClDebugFunc("asan-debug-func", cl::Hidden,
374  cl::desc("Debug func"));
375 
376 static cl::opt<int> ClDebugMin("asan-debug-min", cl::desc("Debug min inst"),
377  cl::Hidden, cl::init(-1));
378 
379 static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug max inst"),
380  cl::Hidden, cl::init(-1));
381 
382 STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
383 STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
384 STATISTIC(NumOptimizedAccessesToGlobalVar,
385  "Number of optimized accesses to global vars");
386 STATISTIC(NumOptimizedAccessesToStackVar,
387  "Number of optimized accesses to stack vars");
388 
389 namespace {
390 
391 /// Frontend-provided metadata for source location.
392 struct LocationMetadata {
393  StringRef Filename;
394  int LineNo = 0;
395  int ColumnNo = 0;
396 
397  LocationMetadata() = default;
398 
399  bool empty() const { return Filename.empty(); }
400 
401  void parse(MDNode *MDN) {
402  assert(MDN->getNumOperands() == 3);
403  MDString *DIFilename = cast<MDString>(MDN->getOperand(0));
404  Filename = DIFilename->getString();
405  LineNo =
406  mdconst::extract<ConstantInt>(MDN->getOperand(1))->getLimitedValue();
407  ColumnNo =
408  mdconst::extract<ConstantInt>(MDN->getOperand(2))->getLimitedValue();
409  }
410 };
411 
412 /// Frontend-provided metadata for global variables.
413 class GlobalsMetadata {
414 public:
415  struct Entry {
416  LocationMetadata SourceLoc;
417  StringRef Name;
418  bool IsDynInit = false;
419  bool IsBlacklisted = false;
420 
421  Entry() = default;
422  };
423 
424  GlobalsMetadata() = default;
425 
426  void reset() {
427  inited_ = false;
428  Entries.clear();
429  }
430 
431  void init(Module &M) {
432  assert(!inited_);
433  inited_ = true;
434  NamedMDNode *Globals = M.getNamedMetadata("llvm.asan.globals");
435  if (!Globals) return;
436  for (auto MDN : Globals->operands()) {
437  // Metadata node contains the global and the fields of "Entry".
438  assert(MDN->getNumOperands() == 5);
439  auto *GV = mdconst::extract_or_null<GlobalVariable>(MDN->getOperand(0));
440  // The optimizer may optimize away a global entirely.
441  if (!GV) continue;
442  // We can already have an entry for GV if it was merged with another
443  // global.
444  Entry &E = Entries[GV];
445  if (auto *Loc = cast_or_null<MDNode>(MDN->getOperand(1)))
446  E.SourceLoc.parse(Loc);
447  if (auto *Name = cast_or_null<MDString>(MDN->getOperand(2)))
448  E.Name = Name->getString();
449  ConstantInt *IsDynInit =
450  mdconst::extract<ConstantInt>(MDN->getOperand(3));
451  E.IsDynInit |= IsDynInit->isOne();
452  ConstantInt *IsBlacklisted =
453  mdconst::extract<ConstantInt>(MDN->getOperand(4));
454  E.IsBlacklisted |= IsBlacklisted->isOne();
455  }
456  }
457 
458  /// Returns metadata entry for a given global.
459  Entry get(GlobalVariable *G) const {
460  auto Pos = Entries.find(G);
461  return (Pos != Entries.end()) ? Pos->second : Entry();
462  }
463 
464 private:
465  bool inited_ = false;
467 };
468 
469 /// This struct defines the shadow mapping using the rule:
470 /// shadow = (mem >> Scale) ADD-or-OR Offset.
471 /// If InGlobal is true, then
472 /// extern char __asan_shadow[];
473 /// shadow = (mem >> Scale) + &__asan_shadow
474 struct ShadowMapping {
475  int Scale;
476  uint64_t Offset;
477  bool OrShadowOffset;
478  bool InGlobal;
479 };
480 
481 } // end anonymous namespace
482 
483 static ShadowMapping getShadowMapping(Triple &TargetTriple, int LongSize,
484  bool IsKasan) {
485  bool IsAndroid = TargetTriple.isAndroid();
486  bool IsIOS = TargetTriple.isiOS() || TargetTriple.isWatchOS();
487  bool IsFreeBSD = TargetTriple.isOSFreeBSD();
488  bool IsNetBSD = TargetTriple.isOSNetBSD();
489  bool IsPS4CPU = TargetTriple.isPS4CPU();
490  bool IsLinux = TargetTriple.isOSLinux();
491  bool IsPPC64 = TargetTriple.getArch() == Triple::ppc64 ||
492  TargetTriple.getArch() == Triple::ppc64le;
493  bool IsSystemZ = TargetTriple.getArch() == Triple::systemz;
494  bool IsX86 = TargetTriple.getArch() == Triple::x86;
495  bool IsX86_64 = TargetTriple.getArch() == Triple::x86_64;
496  bool IsMIPS32 = TargetTriple.isMIPS32();
497  bool IsMIPS64 = TargetTriple.isMIPS64();
498  bool IsArmOrThumb = TargetTriple.isARM() || TargetTriple.isThumb();
499  bool IsAArch64 = TargetTriple.getArch() == Triple::aarch64;
500  bool IsWindows = TargetTriple.isOSWindows();
501  bool IsFuchsia = TargetTriple.isOSFuchsia();
502  bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
503 
504  ShadowMapping Mapping;
505 
506  Mapping.Scale = IsMyriad ? kMyriadShadowScale : kDefaultShadowScale;
507  if (ClMappingScale.getNumOccurrences() > 0) {
508  Mapping.Scale = ClMappingScale;
509  }
510 
511  if (LongSize == 32) {
512  if (IsAndroid)
513  Mapping.Offset = kDynamicShadowSentinel;
514  else if (IsMIPS32)
515  Mapping.Offset = kMIPS32_ShadowOffset32;
516  else if (IsFreeBSD)
517  Mapping.Offset = kFreeBSD_ShadowOffset32;
518  else if (IsNetBSD)
519  Mapping.Offset = kNetBSD_ShadowOffset32;
520  else if (IsIOS)
521  // If we're targeting iOS and x86, the binary is built for iOS simulator.
522  Mapping.Offset = IsX86 ? kIOSSimShadowOffset32 : kIOSShadowOffset32;
523  else if (IsWindows)
524  Mapping.Offset = kWindowsShadowOffset32;
525  else if (IsMyriad) {
526  uint64_t ShadowOffset = (kMyriadMemoryOffset32 + kMyriadMemorySize32 -
527  (kMyriadMemorySize32 >> Mapping.Scale));
528  Mapping.Offset = ShadowOffset - (kMyriadMemoryOffset32 >> Mapping.Scale);
529  }
530  else
531  Mapping.Offset = kDefaultShadowOffset32;
532  } else { // LongSize == 64
533  // Fuchsia is always PIE, which means that the beginning of the address
534  // space is always available.
535  if (IsFuchsia)
536  Mapping.Offset = 0;
537  else if (IsPPC64)
538  Mapping.Offset = kPPC64_ShadowOffset64;
539  else if (IsSystemZ)
540  Mapping.Offset = kSystemZ_ShadowOffset64;
541  else if (IsFreeBSD && !IsMIPS64)
542  Mapping.Offset = kFreeBSD_ShadowOffset64;
543  else if (IsNetBSD)
544  Mapping.Offset = kNetBSD_ShadowOffset64;
545  else if (IsPS4CPU)
546  Mapping.Offset = kPS4CPU_ShadowOffset64;
547  else if (IsLinux && IsX86_64) {
548  if (IsKasan)
549  Mapping.Offset = kLinuxKasan_ShadowOffset64;
550  else
551  Mapping.Offset = (kSmallX86_64ShadowOffsetBase &
552  (kSmallX86_64ShadowOffsetAlignMask << Mapping.Scale));
553  } else if (IsWindows && IsX86_64) {
554  Mapping.Offset = kWindowsShadowOffset64;
555  } else if (IsMIPS64)
556  Mapping.Offset = kMIPS64_ShadowOffset64;
557  else if (IsIOS)
558  // If we're targeting iOS and x86, the binary is built for iOS simulator.
559  // We are using dynamic shadow offset on the 64-bit devices.
560  Mapping.Offset =
562  else if (IsAArch64)
563  Mapping.Offset = kAArch64_ShadowOffset64;
564  else
565  Mapping.Offset = kDefaultShadowOffset64;
566  }
567 
568  if (ClForceDynamicShadow) {
569  Mapping.Offset = kDynamicShadowSentinel;
570  }
571 
572  if (ClMappingOffset.getNumOccurrences() > 0) {
573  Mapping.Offset = ClMappingOffset;
574  }
575 
576  // OR-ing shadow offset if more efficient (at least on x86) if the offset
577  // is a power of two, but on ppc64 we have to use add since the shadow
578  // offset is not necessary 1/8-th of the address space. On SystemZ,
579  // we could OR the constant in a single instruction, but it's more
580  // efficient to load it once and use indexed addressing.
581  Mapping.OrShadowOffset = !IsAArch64 && !IsPPC64 && !IsSystemZ && !IsPS4CPU &&
582  !(Mapping.Offset & (Mapping.Offset - 1)) &&
583  Mapping.Offset != kDynamicShadowSentinel;
584  bool IsAndroidWithIfuncSupport =
585  IsAndroid && !TargetTriple.isAndroidVersionLT(21);
586  Mapping.InGlobal = ClWithIfunc && IsAndroidWithIfuncSupport && IsArmOrThumb;
587 
588  return Mapping;
589 }
590 
591 static size_t RedzoneSizeForScale(int MappingScale) {
592  // Redzone used for stack and globals is at least 32 bytes.
593  // For scales 6 and 7, the redzone has to be 64 and 128 bytes respectively.
594  return std::max(32U, 1U << MappingScale);
595 }
596 
597 namespace {
598 
599 /// AddressSanitizer: instrument the code in module to find memory bugs.
600 struct AddressSanitizer : public FunctionPass {
601  // Pass identification, replacement for typeid
602  static char ID;
603 
604  explicit AddressSanitizer(bool CompileKernel = false, bool Recover = false,
605  bool UseAfterScope = false)
606  : FunctionPass(ID), UseAfterScope(UseAfterScope || ClUseAfterScope) {
607  this->Recover = ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover;
608  this->CompileKernel = ClEnableKasan.getNumOccurrences() > 0 ?
609  ClEnableKasan : CompileKernel;
611  }
612 
613  StringRef getPassName() const override {
614  return "AddressSanitizerFunctionPass";
615  }
616 
617  void getAnalysisUsage(AnalysisUsage &AU) const override {
620  }
621 
622  uint64_t getAllocaSizeInBytes(const AllocaInst &AI) const {
623  uint64_t ArraySize = 1;
624  if (AI.isArrayAllocation()) {
625  const ConstantInt *CI = dyn_cast<ConstantInt>(AI.getArraySize());
626  assert(CI && "non-constant array size");
627  ArraySize = CI->getZExtValue();
628  }
629  Type *Ty = AI.getAllocatedType();
630  uint64_t SizeInBytes =
632  return SizeInBytes * ArraySize;
633  }
634 
635  /// Check if we want (and can) handle this alloca.
636  bool isInterestingAlloca(const AllocaInst &AI);
637 
638  /// If it is an interesting memory access, return the PointerOperand
639  /// and set IsWrite/Alignment. Otherwise return nullptr.
640  /// MaybeMask is an output parameter for the mask Value, if we're looking at a
641  /// masked load/store.
642  Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite,
643  uint64_t *TypeSize, unsigned *Alignment,
644  Value **MaybeMask = nullptr);
645 
646  void instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis, Instruction *I,
647  bool UseCalls, const DataLayout &DL);
648  void instrumentPointerComparisonOrSubtraction(Instruction *I);
649  void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
650  Value *Addr, uint32_t TypeSize, bool IsWrite,
651  Value *SizeArgument, bool UseCalls, uint32_t Exp);
652  void instrumentUnusualSizeOrAlignment(Instruction *I,
653  Instruction *InsertBefore, Value *Addr,
654  uint32_t TypeSize, bool IsWrite,
655  Value *SizeArgument, bool UseCalls,
656  uint32_t Exp);
657  Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
658  Value *ShadowValue, uint32_t TypeSize);
659  Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
660  bool IsWrite, size_t AccessSizeIndex,
661  Value *SizeArgument, uint32_t Exp);
662  void instrumentMemIntrinsic(MemIntrinsic *MI);
663  Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
664  bool runOnFunction(Function &F) override;
665  bool maybeInsertAsanInitAtFunctionEntry(Function &F);
666  void maybeInsertDynamicShadowAtFunctionEntry(Function &F);
667  void markEscapedLocalAllocas(Function &F);
668  bool doInitialization(Module &M) override;
669  bool doFinalization(Module &M) override;
670 
671  DominatorTree &getDominatorTree() const { return *DT; }
672 
673 private:
674  friend struct FunctionStackPoisoner;
675 
676  void initializeCallbacks(Module &M);
677 
678  bool LooksLikeCodeInBug11395(Instruction *I);
679  bool GlobalIsLinkerInitialized(GlobalVariable *G);
680  bool isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis, Value *Addr,
681  uint64_t TypeSize) const;
682 
683  /// Helper to cleanup per-function state.
684  struct FunctionStateRAII {
685  AddressSanitizer *Pass;
686 
687  FunctionStateRAII(AddressSanitizer *Pass) : Pass(Pass) {
688  assert(Pass->ProcessedAllocas.empty() &&
689  "last pass forgot to clear cache");
690  assert(!Pass->LocalDynamicShadow);
691  }
692 
693  ~FunctionStateRAII() {
694  Pass->LocalDynamicShadow = nullptr;
695  Pass->ProcessedAllocas.clear();
696  }
697  };
698 
699  LLVMContext *C;
700  Triple TargetTriple;
701  int LongSize;
702  bool CompileKernel;
703  bool Recover;
704  bool UseAfterScope;
705  Type *IntptrTy;
706  ShadowMapping Mapping;
707  DominatorTree *DT;
708  Function *AsanHandleNoReturnFunc;
709  Function *AsanPtrCmpFunction, *AsanPtrSubFunction;
710  Constant *AsanShadowGlobal;
711 
712  // These arrays is indexed by AccessIsWrite, Experiment and log2(AccessSize).
713  Function *AsanErrorCallback[2][2][kNumberOfAccessSizes];
714  Function *AsanMemoryAccessCallback[2][2][kNumberOfAccessSizes];
715 
716  // These arrays is indexed by AccessIsWrite and Experiment.
717  Function *AsanErrorCallbackSized[2][2];
718  Function *AsanMemoryAccessCallbackSized[2][2];
719 
720  Function *AsanMemmove, *AsanMemcpy, *AsanMemset;
721  InlineAsm *EmptyAsm;
722  Value *LocalDynamicShadow = nullptr;
723  GlobalsMetadata GlobalsMD;
724  DenseMap<const AllocaInst *, bool> ProcessedAllocas;
725 };
726 
727 class AddressSanitizerModule : public ModulePass {
728 public:
729  // Pass identification, replacement for typeid
730  static char ID;
731 
732  explicit AddressSanitizerModule(bool CompileKernel = false,
733  bool Recover = false,
734  bool UseGlobalsGC = true)
735  : ModulePass(ID),
736  UseGlobalsGC(UseGlobalsGC && ClUseGlobalsGC),
737  // Not a typo: ClWithComdat is almost completely pointless without
738  // ClUseGlobalsGC (because then it only works on modules without
739  // globals, which are rare); it is a prerequisite for ClUseGlobalsGC;
740  // and both suffer from gold PR19002 for which UseGlobalsGC constructor
741  // argument is designed as workaround. Therefore, disable both
742  // ClWithComdat and ClUseGlobalsGC unless the frontend says it's ok to
743  // do globals-gc.
744  UseCtorComdat(UseGlobalsGC && ClWithComdat) {
745  this->Recover = ClRecover.getNumOccurrences() > 0 ?
746  ClRecover : Recover;
747  this->CompileKernel = ClEnableKasan.getNumOccurrences() > 0 ?
748  ClEnableKasan : CompileKernel;
749  }
750 
751  bool runOnModule(Module &M) override;
752  StringRef getPassName() const override { return "AddressSanitizerModule"; }
753 
754 private:
755  void initializeCallbacks(Module &M);
756 
757  bool InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat);
758  void InstrumentGlobalsCOFF(IRBuilder<> &IRB, Module &M,
759  ArrayRef<GlobalVariable *> ExtendedGlobals,
760  ArrayRef<Constant *> MetadataInitializers);
761  void InstrumentGlobalsELF(IRBuilder<> &IRB, Module &M,
762  ArrayRef<GlobalVariable *> ExtendedGlobals,
763  ArrayRef<Constant *> MetadataInitializers,
764  const std::string &UniqueModuleId);
765  void InstrumentGlobalsMachO(IRBuilder<> &IRB, Module &M,
766  ArrayRef<GlobalVariable *> ExtendedGlobals,
767  ArrayRef<Constant *> MetadataInitializers);
768  void
769  InstrumentGlobalsWithMetadataArray(IRBuilder<> &IRB, Module &M,
770  ArrayRef<GlobalVariable *> ExtendedGlobals,
771  ArrayRef<Constant *> MetadataInitializers);
772 
773  GlobalVariable *CreateMetadataGlobal(Module &M, Constant *Initializer,
774  StringRef OriginalName);
775  void SetComdatForGlobalMetadata(GlobalVariable *G, GlobalVariable *Metadata,
776  StringRef InternalSuffix);
777  IRBuilder<> CreateAsanModuleDtor(Module &M);
778 
779  bool ShouldInstrumentGlobal(GlobalVariable *G);
780  bool ShouldUseMachOGlobalsSection() const;
781  StringRef getGlobalMetadataSection() const;
782  void poisonOneInitializer(Function &GlobalInit, GlobalValue *ModuleName);
783  void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
784  size_t MinRedzoneSizeForGlobal() const {
785  return RedzoneSizeForScale(Mapping.Scale);
786  }
787  int GetAsanVersion(const Module &M) const;
788 
789  GlobalsMetadata GlobalsMD;
790  bool CompileKernel;
791  bool Recover;
792  bool UseGlobalsGC;
793  bool UseCtorComdat;
794  Type *IntptrTy;
795  LLVMContext *C;
796  Triple TargetTriple;
797  ShadowMapping Mapping;
798  Function *AsanPoisonGlobals;
799  Function *AsanUnpoisonGlobals;
800  Function *AsanRegisterGlobals;
801  Function *AsanUnregisterGlobals;
802  Function *AsanRegisterImageGlobals;
803  Function *AsanUnregisterImageGlobals;
804  Function *AsanRegisterElfGlobals;
805  Function *AsanUnregisterElfGlobals;
806 
807  Function *AsanCtorFunction = nullptr;
808  Function *AsanDtorFunction = nullptr;
809 };
810 
811 // Stack poisoning does not play well with exception handling.
812 // When an exception is thrown, we essentially bypass the code
813 // that unpoisones the stack. This is why the run-time library has
814 // to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
815 // stack in the interceptor. This however does not work inside the
816 // actual function which catches the exception. Most likely because the
817 // compiler hoists the load of the shadow value somewhere too high.
818 // This causes asan to report a non-existing bug on 453.povray.
819 // It sounds like an LLVM bug.
820 struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
821  Function &F;
822  AddressSanitizer &ASan;
823  DIBuilder DIB;
824  LLVMContext *C;
825  Type *IntptrTy;
826  Type *IntptrPtrTy;
827  ShadowMapping Mapping;
828 
830  SmallVector<AllocaInst *, 16> StaticAllocasToMoveUp;
832  unsigned StackAlignment;
833 
834  Function *AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
835  *AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
836  Function *AsanSetShadowFunc[0x100] = {};
837  Function *AsanPoisonStackMemoryFunc, *AsanUnpoisonStackMemoryFunc;
838  Function *AsanAllocaPoisonFunc, *AsanAllocasUnpoisonFunc;
839 
840  // Stores a place and arguments of poisoning/unpoisoning call for alloca.
841  struct AllocaPoisonCall {
842  IntrinsicInst *InsBefore;
843  AllocaInst *AI;
844  uint64_t Size;
845  bool DoPoison;
846  };
847  SmallVector<AllocaPoisonCall, 8> DynamicAllocaPoisonCallVec;
848  SmallVector<AllocaPoisonCall, 8> StaticAllocaPoisonCallVec;
849 
850  SmallVector<AllocaInst *, 1> DynamicAllocaVec;
851  SmallVector<IntrinsicInst *, 1> StackRestoreVec;
852  AllocaInst *DynamicAllocaLayout = nullptr;
853  IntrinsicInst *LocalEscapeCall = nullptr;
854 
855  // Maps Value to an AllocaInst from which the Value is originated.
856  using AllocaForValueMapTy = DenseMap<Value *, AllocaInst *>;
857  AllocaForValueMapTy AllocaForValue;
858 
859  bool HasNonEmptyInlineAsm = false;
860  bool HasReturnsTwiceCall = false;
861  std::unique_ptr<CallInst> EmptyInlineAsm;
862 
863  FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
864  : F(F),
865  ASan(ASan),
866  DIB(*F.getParent(), /*AllowUnresolved*/ false),
867  C(ASan.C),
868  IntptrTy(ASan.IntptrTy),
869  IntptrPtrTy(PointerType::get(IntptrTy, 0)),
870  Mapping(ASan.Mapping),
871  StackAlignment(1 << Mapping.Scale),
872  EmptyInlineAsm(CallInst::Create(ASan.EmptyAsm)) {}
873 
874  bool runOnFunction() {
875  if (!ClStack) return false;
876 
877  if (ClRedzoneByvalArgs)
878  copyArgsPassedByValToAllocas();
879 
880  // Collect alloca, ret, lifetime instructions etc.
881  for (BasicBlock *BB : depth_first(&F.getEntryBlock())) visit(*BB);
882 
883  if (AllocaVec.empty() && DynamicAllocaVec.empty()) return false;
884 
885  initializeCallbacks(*F.getParent());
886 
887  processDynamicAllocas();
888  processStaticAllocas();
889 
890  if (ClDebugStack) {
891  LLVM_DEBUG(dbgs() << F);
892  }
893  return true;
894  }
895 
896  // Arguments marked with the "byval" attribute are implicitly copied without
897  // using an alloca instruction. To produce redzones for those arguments, we
898  // copy them a second time into memory allocated with an alloca instruction.
899  void copyArgsPassedByValToAllocas();
900 
901  // Finds all Alloca instructions and puts
902  // poisoned red zones around all of them.
903  // Then unpoison everything back before the function returns.
904  void processStaticAllocas();
905  void processDynamicAllocas();
906 
907  void createDynamicAllocasInitStorage();
908 
909  // ----------------------- Visitors.
910  /// Collect all Ret instructions.
911  void visitReturnInst(ReturnInst &RI) { RetVec.push_back(&RI); }
912 
913  /// Collect all Resume instructions.
914  void visitResumeInst(ResumeInst &RI) { RetVec.push_back(&RI); }
915 
916  /// Collect all CatchReturnInst instructions.
917  void visitCleanupReturnInst(CleanupReturnInst &CRI) { RetVec.push_back(&CRI); }
918 
919  void unpoisonDynamicAllocasBeforeInst(Instruction *InstBefore,
920  Value *SavedStack) {
921  IRBuilder<> IRB(InstBefore);
922  Value *DynamicAreaPtr = IRB.CreatePtrToInt(SavedStack, IntptrTy);
923  // When we insert _asan_allocas_unpoison before @llvm.stackrestore, we
924  // need to adjust extracted SP to compute the address of the most recent
925  // alloca. We have a special @llvm.get.dynamic.area.offset intrinsic for
926  // this purpose.
927  if (!isa<ReturnInst>(InstBefore)) {
928  Function *DynamicAreaOffsetFunc = Intrinsic::getDeclaration(
929  InstBefore->getModule(), Intrinsic::get_dynamic_area_offset,
930  {IntptrTy});
931 
932  Value *DynamicAreaOffset = IRB.CreateCall(DynamicAreaOffsetFunc, {});
933 
934  DynamicAreaPtr = IRB.CreateAdd(IRB.CreatePtrToInt(SavedStack, IntptrTy),
935  DynamicAreaOffset);
936  }
937 
938  IRB.CreateCall(AsanAllocasUnpoisonFunc,
939  {IRB.CreateLoad(DynamicAllocaLayout), DynamicAreaPtr});
940  }
941 
942  // Unpoison dynamic allocas redzones.
943  void unpoisonDynamicAllocas() {
944  for (auto &Ret : RetVec)
945  unpoisonDynamicAllocasBeforeInst(Ret, DynamicAllocaLayout);
946 
947  for (auto &StackRestoreInst : StackRestoreVec)
948  unpoisonDynamicAllocasBeforeInst(StackRestoreInst,
949  StackRestoreInst->getOperand(0));
950  }
951 
952  // Deploy and poison redzones around dynamic alloca call. To do this, we
953  // should replace this call with another one with changed parameters and
954  // replace all its uses with new address, so
955  // addr = alloca type, old_size, align
956  // is replaced by
957  // new_size = (old_size + additional_size) * sizeof(type)
958  // tmp = alloca i8, new_size, max(align, 32)
959  // addr = tmp + 32 (first 32 bytes are for the left redzone).
960  // Additional_size is added to make new memory allocation contain not only
961  // requested memory, but also left, partial and right redzones.
962  void handleDynamicAllocaCall(AllocaInst *AI);
963 
964  /// Collect Alloca instructions we want (and can) handle.
965  void visitAllocaInst(AllocaInst &AI) {
966  if (!ASan.isInterestingAlloca(AI)) {
967  if (AI.isStaticAlloca()) {
968  // Skip over allocas that are present *before* the first instrumented
969  // alloca, we don't want to move those around.
970  if (AllocaVec.empty())
971  return;
972 
973  StaticAllocasToMoveUp.push_back(&AI);
974  }
975  return;
976  }
977 
978  StackAlignment = std::max(StackAlignment, AI.getAlignment());
979  if (!AI.isStaticAlloca())
980  DynamicAllocaVec.push_back(&AI);
981  else
982  AllocaVec.push_back(&AI);
983  }
984 
985  /// Collect lifetime intrinsic calls to check for use-after-scope
986  /// errors.
987  void visitIntrinsicInst(IntrinsicInst &II) {
989  if (ID == Intrinsic::stackrestore) StackRestoreVec.push_back(&II);
990  if (ID == Intrinsic::localescape) LocalEscapeCall = &II;
991  if (!ASan.UseAfterScope)
992  return;
993  if (ID != Intrinsic::lifetime_start && ID != Intrinsic::lifetime_end)
994  return;
995  // Found lifetime intrinsic, add ASan instrumentation if necessary.
997  // If size argument is undefined, don't do anything.
998  if (Size->isMinusOne()) return;
999  // Check that size doesn't saturate uint64_t and can
1000  // be stored in IntptrTy.
1001  const uint64_t SizeValue = Size->getValue().getLimitedValue();
1002  if (SizeValue == ~0ULL ||
1003  !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
1004  return;
1005  // Find alloca instruction that corresponds to llvm.lifetime argument.
1006  AllocaInst *AI = findAllocaForValue(II.getArgOperand(1));
1007  if (!AI || !ASan.isInterestingAlloca(*AI))
1008  return;
1009  bool DoPoison = (ID == Intrinsic::lifetime_end);
1010  AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
1011  if (AI->isStaticAlloca())
1012  StaticAllocaPoisonCallVec.push_back(APC);
1013  else if (ClInstrumentDynamicAllocas)
1014  DynamicAllocaPoisonCallVec.push_back(APC);
1015  }
1016 
1017  void visitCallSite(CallSite CS) {
1018  Instruction *I = CS.getInstruction();
1019  if (CallInst *CI = dyn_cast<CallInst>(I)) {
1020  HasNonEmptyInlineAsm |= CI->isInlineAsm() &&
1021  !CI->isIdenticalTo(EmptyInlineAsm.get()) &&
1022  I != ASan.LocalDynamicShadow;
1023  HasReturnsTwiceCall |= CI->canReturnTwice();
1024  }
1025  }
1026 
1027  // ---------------------- Helpers.
1028  void initializeCallbacks(Module &M);
1029 
1030  bool doesDominateAllExits(const Instruction *I) const {
1031  for (auto Ret : RetVec) {
1032  if (!ASan.getDominatorTree().dominates(I, Ret)) return false;
1033  }
1034  return true;
1035  }
1036 
1037  /// Finds alloca where the value comes from.
1038  AllocaInst *findAllocaForValue(Value *V);
1039 
1040  // Copies bytes from ShadowBytes into shadow memory for indexes where
1041  // ShadowMask is not zero. If ShadowMask[i] is zero, we assume that
1042  // ShadowBytes[i] is constantly zero and doesn't need to be overwritten.
1043  void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1044  IRBuilder<> &IRB, Value *ShadowBase);
1045  void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1046  size_t Begin, size_t End, IRBuilder<> &IRB,
1047  Value *ShadowBase);
1048  void copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
1049  ArrayRef<uint8_t> ShadowBytes, size_t Begin,
1050  size_t End, IRBuilder<> &IRB, Value *ShadowBase);
1051 
1052  void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
1053 
1054  Value *createAllocaForLayout(IRBuilder<> &IRB, const ASanStackFrameLayout &L,
1055  bool Dynamic);
1056  PHINode *createPHI(IRBuilder<> &IRB, Value *Cond, Value *ValueIfTrue,
1057  Instruction *ThenTerm, Value *ValueIfFalse);
1058 };
1059 
1060 } // end anonymous namespace
1061 
1062 char AddressSanitizer::ID = 0;
1063 
1065  AddressSanitizer, "asan",
1066  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,
1067  false)
1071  AddressSanitizer, "asan",
1072  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,
1073  false)
1074 
1076  bool Recover,
1077  bool UseAfterScope) {
1078  assert(!CompileKernel || Recover);
1079  return new AddressSanitizer(CompileKernel, Recover, UseAfterScope);
1080 }
1081 
1083 
1085  AddressSanitizerModule, "asan-module",
1086  "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
1087  "ModulePass",
1088  false, false)
1089 
1090 ModulePass *llvm::createAddressSanitizerModulePass(bool CompileKernel,
1091  bool Recover,
1092  bool UseGlobalsGC) {
1093  assert(!CompileKernel || Recover);
1094  return new AddressSanitizerModule(CompileKernel, Recover, UseGlobalsGC);
1095 }
1096 
1097 static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
1098  size_t Res = countTrailingZeros(TypeSize / 8);
1100  return Res;
1101 }
1102 
1103 // Create a constant for Str so that we can pass it to the run-time lib.
1105  bool AllowMerging) {
1106  Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
1107  // We use private linkage for module-local strings. If they can be merged
1108  // with another one, we set the unnamed_addr attribute.
1109  GlobalVariable *GV =
1110  new GlobalVariable(M, StrConst->getType(), true,
1112  if (AllowMerging) GV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
1113  GV->setAlignment(1); // Strings may not be merged w/o setting align 1.
1114  return GV;
1115 }
1116 
1117 /// Create a global describing a source location.
1119  LocationMetadata MD) {
1120  Constant *LocData[] = {
1121  createPrivateGlobalForString(M, MD.Filename, true),
1122  ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.LineNo),
1123  ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.ColumnNo),
1124  };
1125  auto LocStruct = ConstantStruct::getAnon(LocData);
1126  auto GV = new GlobalVariable(M, LocStruct->getType(), true,
1127  GlobalValue::PrivateLinkage, LocStruct,
1128  kAsanGenPrefix);
1130  return GV;
1131 }
1132 
1133 /// Check if \p G has been created by a trusted compiler pass.
1135  // Do not instrument asan globals.
1136  if (G->getName().startswith(kAsanGenPrefix) ||
1137  G->getName().startswith(kSanCovGenPrefix) ||
1138  G->getName().startswith(kODRGenPrefix))
1139  return true;
1140 
1141  // Do not instrument gcov counter arrays.
1142  if (G->getName() == "__llvm_gcov_ctr")
1143  return true;
1144 
1145  return false;
1146 }
1147 
1148 Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
1149  // Shadow >> scale
1150  Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
1151  if (Mapping.Offset == 0) return Shadow;
1152  // (Shadow >> scale) | offset
1153  Value *ShadowBase;
1154  if (LocalDynamicShadow)
1155  ShadowBase = LocalDynamicShadow;
1156  else
1157  ShadowBase = ConstantInt::get(IntptrTy, Mapping.Offset);
1158  if (Mapping.OrShadowOffset)
1159  return IRB.CreateOr(Shadow, ShadowBase);
1160  else
1161  return IRB.CreateAdd(Shadow, ShadowBase);
1162 }
1163 
1164 // Instrument memset/memmove/memcpy
1165 void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
1166  IRBuilder<> IRB(MI);
1167  if (isa<MemTransferInst>(MI)) {
1168  IRB.CreateCall(
1169  isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
1170  {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1171  IRB.CreatePointerCast(MI->getOperand(1), IRB.getInt8PtrTy()),
1172  IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1173  } else if (isa<MemSetInst>(MI)) {
1174  IRB.CreateCall(
1175  AsanMemset,
1176  {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1177  IRB.CreateIntCast(MI->getOperand(1), IRB.getInt32Ty(), false),
1178  IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1179  }
1180  MI->eraseFromParent();
1181 }
1182 
1183 /// Check if we want (and can) handle this alloca.
1184 bool AddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
1185  auto PreviouslySeenAllocaInfo = ProcessedAllocas.find(&AI);
1186 
1187  if (PreviouslySeenAllocaInfo != ProcessedAllocas.end())
1188  return PreviouslySeenAllocaInfo->getSecond();
1189 
1190  bool IsInteresting =
1191  (AI.getAllocatedType()->isSized() &&
1192  // alloca() may be called with 0 size, ignore it.
1193  ((!AI.isStaticAlloca()) || getAllocaSizeInBytes(AI) > 0) &&
1194  // We are only interested in allocas not promotable to registers.
1195  // Promotable allocas are common under -O0.
1197  // inalloca allocas are not treated as static, and we don't want
1198  // dynamic alloca instrumentation for them as well.
1199  !AI.isUsedWithInAlloca() &&
1200  // swifterror allocas are register promoted by ISel
1201  !AI.isSwiftError());
1202 
1203  ProcessedAllocas[&AI] = IsInteresting;
1204  return IsInteresting;
1205 }
1206 
1207 Value *AddressSanitizer::isInterestingMemoryAccess(Instruction *I,
1208  bool *IsWrite,
1209  uint64_t *TypeSize,
1210  unsigned *Alignment,
1211  Value **MaybeMask) {
1212  // Skip memory accesses inserted by another instrumentation.
1213  if (I->getMetadata("nosanitize")) return nullptr;
1214 
1215  // Do not instrument the load fetching the dynamic shadow address.
1216  if (LocalDynamicShadow == I)
1217  return nullptr;
1218 
1219  Value *PtrOperand = nullptr;
1220  const DataLayout &DL = I->getModule()->getDataLayout();
1221  if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
1222  if (!ClInstrumentReads) return nullptr;
1223  *IsWrite = false;
1224  *TypeSize = DL.getTypeStoreSizeInBits(LI->getType());
1225  *Alignment = LI->getAlignment();
1226  PtrOperand = LI->getPointerOperand();
1227  } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
1228  if (!ClInstrumentWrites) return nullptr;
1229  *IsWrite = true;
1230  *TypeSize = DL.getTypeStoreSizeInBits(SI->getValueOperand()->getType());
1231  *Alignment = SI->getAlignment();
1232  PtrOperand = SI->getPointerOperand();
1233  } else if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
1234  if (!ClInstrumentAtomics) return nullptr;
1235  *IsWrite = true;
1236  *TypeSize = DL.getTypeStoreSizeInBits(RMW->getValOperand()->getType());
1237  *Alignment = 0;
1238  PtrOperand = RMW->getPointerOperand();
1239  } else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
1240  if (!ClInstrumentAtomics) return nullptr;
1241  *IsWrite = true;
1242  *TypeSize = DL.getTypeStoreSizeInBits(XCHG->getCompareOperand()->getType());
1243  *Alignment = 0;
1244  PtrOperand = XCHG->getPointerOperand();
1245  } else if (auto CI = dyn_cast<CallInst>(I)) {
1246  auto *F = dyn_cast<Function>(CI->getCalledValue());
1247  if (F && (F->getName().startswith("llvm.masked.load.") ||
1248  F->getName().startswith("llvm.masked.store."))) {
1249  unsigned OpOffset = 0;
1250  if (F->getName().startswith("llvm.masked.store.")) {
1251  if (!ClInstrumentWrites)
1252  return nullptr;
1253  // Masked store has an initial operand for the value.
1254  OpOffset = 1;
1255  *IsWrite = true;
1256  } else {
1257  if (!ClInstrumentReads)
1258  return nullptr;
1259  *IsWrite = false;
1260  }
1261 
1262  auto BasePtr = CI->getOperand(0 + OpOffset);
1263  auto Ty = cast<PointerType>(BasePtr->getType())->getElementType();
1264  *TypeSize = DL.getTypeStoreSizeInBits(Ty);
1265  if (auto AlignmentConstant =
1266  dyn_cast<ConstantInt>(CI->getOperand(1 + OpOffset)))
1267  *Alignment = (unsigned)AlignmentConstant->getZExtValue();
1268  else
1269  *Alignment = 1; // No alignment guarantees. We probably got Undef
1270  if (MaybeMask)
1271  *MaybeMask = CI->getOperand(2 + OpOffset);
1272  PtrOperand = BasePtr;
1273  }
1274  }
1275 
1276  if (PtrOperand) {
1277  // Do not instrument acesses from different address spaces; we cannot deal
1278  // with them.
1279  Type *PtrTy = cast<PointerType>(PtrOperand->getType()->getScalarType());
1280  if (PtrTy->getPointerAddressSpace() != 0)
1281  return nullptr;
1282 
1283  // Ignore swifterror addresses.
1284  // swifterror memory addresses are mem2reg promoted by instruction
1285  // selection. As such they cannot have regular uses like an instrumentation
1286  // function and it makes no sense to track them as memory.
1287  if (PtrOperand->isSwiftError())
1288  return nullptr;
1289  }
1290 
1291  // Treat memory accesses to promotable allocas as non-interesting since they
1292  // will not cause memory violations. This greatly speeds up the instrumented
1293  // executable at -O0.
1295  if (auto AI = dyn_cast_or_null<AllocaInst>(PtrOperand))
1296  return isInterestingAlloca(*AI) ? AI : nullptr;
1297 
1298  return PtrOperand;
1299 }
1300 
1301 static bool isPointerOperand(Value *V) {
1302  return V->getType()->isPointerTy() || isa<PtrToIntInst>(V);
1303 }
1304 
1305 // This is a rough heuristic; it may cause both false positives and
1306 // false negatives. The proper implementation requires cooperation with
1307 // the frontend.
1309  if (ICmpInst *Cmp = dyn_cast<ICmpInst>(I)) {
1310  if (!Cmp->isRelational()) return false;
1311  } else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) {
1312  if (BO->getOpcode() != Instruction::Sub) return false;
1313  } else {
1314  return false;
1315  }
1316  return isPointerOperand(I->getOperand(0)) &&
1318 }
1319 
1320 bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
1321  // If a global variable does not have dynamic initialization we don't
1322  // have to instrument it. However, if a global does not have initializer
1323  // at all, we assume it has dynamic initializer (in other TU).
1324  return G->hasInitializer() && !GlobalsMD.get(G).IsDynInit;
1325 }
1326 
1327 void AddressSanitizer::instrumentPointerComparisonOrSubtraction(
1328  Instruction *I) {
1329  IRBuilder<> IRB(I);
1330  Function *F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
1331  Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
1332  for (Value *&i : Param) {
1333  if (i->getType()->isPointerTy())
1334  i = IRB.CreatePointerCast(i, IntptrTy);
1335  }
1336  IRB.CreateCall(F, Param);
1337 }
1338 
1339 static void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I,
1340  Instruction *InsertBefore, Value *Addr,
1341  unsigned Alignment, unsigned Granularity,
1342  uint32_t TypeSize, bool IsWrite,
1343  Value *SizeArgument, bool UseCalls,
1344  uint32_t Exp) {
1345  // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check
1346  // if the data is properly aligned.
1347  if ((TypeSize == 8 || TypeSize == 16 || TypeSize == 32 || TypeSize == 64 ||
1348  TypeSize == 128) &&
1349  (Alignment >= Granularity || Alignment == 0 || Alignment >= TypeSize / 8))
1350  return Pass->instrumentAddress(I, InsertBefore, Addr, TypeSize, IsWrite,
1351  nullptr, UseCalls, Exp);
1352  Pass->instrumentUnusualSizeOrAlignment(I, InsertBefore, Addr, TypeSize,
1353  IsWrite, nullptr, UseCalls, Exp);
1354 }
1355 
1356 static void instrumentMaskedLoadOrStore(AddressSanitizer *Pass,
1357  const DataLayout &DL, Type *IntptrTy,
1358  Value *Mask, Instruction *I,
1359  Value *Addr, unsigned Alignment,
1360  unsigned Granularity, uint32_t TypeSize,
1361  bool IsWrite, Value *SizeArgument,
1362  bool UseCalls, uint32_t Exp) {
1363  auto *VTy = cast<PointerType>(Addr->getType())->getElementType();
1364  uint64_t ElemTypeSize = DL.getTypeStoreSizeInBits(VTy->getScalarType());
1365  unsigned Num = VTy->getVectorNumElements();
1366  auto Zero = ConstantInt::get(IntptrTy, 0);
1367  for (unsigned Idx = 0; Idx < Num; ++Idx) {
1368  Value *InstrumentedAddress = nullptr;
1369  Instruction *InsertBefore = I;
1370  if (auto *Vector = dyn_cast<ConstantVector>(Mask)) {
1371  // dyn_cast as we might get UndefValue
1372  if (auto *Masked = dyn_cast<ConstantInt>(Vector->getOperand(Idx))) {
1373  if (Masked->isZero())
1374  // Mask is constant false, so no instrumentation needed.
1375  continue;
1376  // If we have a true or undef value, fall through to doInstrumentAddress
1377  // with InsertBefore == I
1378  }
1379  } else {
1380  IRBuilder<> IRB(I);
1381  Value *MaskElem = IRB.CreateExtractElement(Mask, Idx);
1382  TerminatorInst *ThenTerm = SplitBlockAndInsertIfThen(MaskElem, I, false);
1383  InsertBefore = ThenTerm;
1384  }
1385 
1386  IRBuilder<> IRB(InsertBefore);
1387  InstrumentedAddress =
1388  IRB.CreateGEP(Addr, {Zero, ConstantInt::get(IntptrTy, Idx)});
1389  doInstrumentAddress(Pass, I, InsertBefore, InstrumentedAddress, Alignment,
1390  Granularity, ElemTypeSize, IsWrite, SizeArgument,
1391  UseCalls, Exp);
1392  }
1393 }
1394 
1395 void AddressSanitizer::instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
1396  Instruction *I, bool UseCalls,
1397  const DataLayout &DL) {
1398  bool IsWrite = false;
1399  unsigned Alignment = 0;
1400  uint64_t TypeSize = 0;
1401  Value *MaybeMask = nullptr;
1402  Value *Addr =
1403  isInterestingMemoryAccess(I, &IsWrite, &TypeSize, &Alignment, &MaybeMask);
1404  assert(Addr);
1405 
1406  // Optimization experiments.
1407  // The experiments can be used to evaluate potential optimizations that remove
1408  // instrumentation (assess false negatives). Instead of completely removing
1409  // some instrumentation, you set Exp to a non-zero value (mask of optimization
1410  // experiments that want to remove instrumentation of this instruction).
1411  // If Exp is non-zero, this pass will emit special calls into runtime
1412  // (e.g. __asan_report_exp_load1 instead of __asan_report_load1). These calls
1413  // make runtime terminate the program in a special way (with a different
1414  // exit status). Then you run the new compiler on a buggy corpus, collect
1415  // the special terminations (ideally, you don't see them at all -- no false
1416  // negatives) and make the decision on the optimization.
1418 
1419  if (ClOpt && ClOptGlobals) {
1420  // If initialization order checking is disabled, a simple access to a
1421  // dynamically initialized global is always valid.
1423  if (G && (!ClInitializers || GlobalIsLinkerInitialized(G)) &&
1424  isSafeAccess(ObjSizeVis, Addr, TypeSize)) {
1425  NumOptimizedAccessesToGlobalVar++;
1426  return;
1427  }
1428  }
1429 
1430  if (ClOpt && ClOptStack) {
1431  // A direct inbounds access to a stack variable is always valid.
1432  if (isa<AllocaInst>(GetUnderlyingObject(Addr, DL)) &&
1433  isSafeAccess(ObjSizeVis, Addr, TypeSize)) {
1434  NumOptimizedAccessesToStackVar++;
1435  return;
1436  }
1437  }
1438 
1439  if (IsWrite)
1440  NumInstrumentedWrites++;
1441  else
1442  NumInstrumentedReads++;
1443 
1444  unsigned Granularity = 1 << Mapping.Scale;
1445  if (MaybeMask) {
1446  instrumentMaskedLoadOrStore(this, DL, IntptrTy, MaybeMask, I, Addr,
1447  Alignment, Granularity, TypeSize, IsWrite,
1448  nullptr, UseCalls, Exp);
1449  } else {
1450  doInstrumentAddress(this, I, I, Addr, Alignment, Granularity, TypeSize,
1451  IsWrite, nullptr, UseCalls, Exp);
1452  }
1453 }
1454 
1455 Instruction *AddressSanitizer::generateCrashCode(Instruction *InsertBefore,
1456  Value *Addr, bool IsWrite,
1457  size_t AccessSizeIndex,
1458  Value *SizeArgument,
1459  uint32_t Exp) {
1460  IRBuilder<> IRB(InsertBefore);
1461  Value *ExpVal = Exp == 0 ? nullptr : ConstantInt::get(IRB.getInt32Ty(), Exp);
1462  CallInst *Call = nullptr;
1463  if (SizeArgument) {
1464  if (Exp == 0)
1465  Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][0],
1466  {Addr, SizeArgument});
1467  else
1468  Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][1],
1469  {Addr, SizeArgument, ExpVal});
1470  } else {
1471  if (Exp == 0)
1472  Call =
1473  IRB.CreateCall(AsanErrorCallback[IsWrite][0][AccessSizeIndex], Addr);
1474  else
1475  Call = IRB.CreateCall(AsanErrorCallback[IsWrite][1][AccessSizeIndex],
1476  {Addr, ExpVal});
1477  }
1478 
1479  // We don't do Call->setDoesNotReturn() because the BB already has
1480  // UnreachableInst at the end.
1481  // This EmptyAsm is required to avoid callback merge.
1482  IRB.CreateCall(EmptyAsm, {});
1483  return Call;
1484 }
1485 
1486 Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
1487  Value *ShadowValue,
1488  uint32_t TypeSize) {
1489  size_t Granularity = static_cast<size_t>(1) << Mapping.Scale;
1490  // Addr & (Granularity - 1)
1491  Value *LastAccessedByte =
1492  IRB.CreateAnd(AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
1493  // (Addr & (Granularity - 1)) + size - 1
1494  if (TypeSize / 8 > 1)
1495  LastAccessedByte = IRB.CreateAdd(
1496  LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1));
1497  // (uint8_t) ((Addr & (Granularity-1)) + size - 1)
1498  LastAccessedByte =
1499  IRB.CreateIntCast(LastAccessedByte, ShadowValue->getType(), false);
1500  // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
1501  return IRB.CreateICmpSGE(LastAccessedByte, ShadowValue);
1502 }
1503 
1504 void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
1505  Instruction *InsertBefore, Value *Addr,
1506  uint32_t TypeSize, bool IsWrite,
1507  Value *SizeArgument, bool UseCalls,
1508  uint32_t Exp) {
1509  bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
1510 
1511  IRBuilder<> IRB(InsertBefore);
1512  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1513  size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
1514 
1515  if (UseCalls) {
1516  if (Exp == 0)
1517  IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][0][AccessSizeIndex],
1518  AddrLong);
1519  else
1520  IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][1][AccessSizeIndex],
1521  {AddrLong, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1522  return;
1523  }
1524 
1525  if (IsMyriad) {
1526  // Strip the cache bit and do range check.
1527  // AddrLong &= ~kMyriadCacheBitMask32
1528  AddrLong = IRB.CreateAnd(AddrLong, ~kMyriadCacheBitMask32);
1529  // Tag = AddrLong >> kMyriadTagShift
1530  Value *Tag = IRB.CreateLShr(AddrLong, kMyriadTagShift);
1531  // Tag == kMyriadDDRTag
1532  Value *TagCheck =
1533  IRB.CreateICmpEQ(Tag, ConstantInt::get(IntptrTy, kMyriadDDRTag));
1534 
1535  TerminatorInst *TagCheckTerm = SplitBlockAndInsertIfThen(
1536  TagCheck, InsertBefore, false, MDBuilder(*C).createBranchWeights(1, 100000));
1537  assert(cast<BranchInst>(TagCheckTerm)->isUnconditional());
1538  IRB.SetInsertPoint(TagCheckTerm);
1539  InsertBefore = TagCheckTerm;
1540  }
1541 
1542  Type *ShadowTy =
1543  IntegerType::get(*C, std::max(8U, TypeSize >> Mapping.Scale));
1544  Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
1545  Value *ShadowPtr = memToShadow(AddrLong, IRB);
1546  Value *CmpVal = Constant::getNullValue(ShadowTy);
1547  Value *ShadowValue =
1548  IRB.CreateLoad(IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));
1549 
1550  Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
1551  size_t Granularity = 1ULL << Mapping.Scale;
1552  TerminatorInst *CrashTerm = nullptr;
1553 
1554  if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
1555  // We use branch weights for the slow path check, to indicate that the slow
1556  // path is rarely taken. This seems to be the case for SPEC benchmarks.
1558  Cmp, InsertBefore, false, MDBuilder(*C).createBranchWeights(1, 100000));
1559  assert(cast<BranchInst>(CheckTerm)->isUnconditional());
1560  BasicBlock *NextBB = CheckTerm->getSuccessor(0);
1561  IRB.SetInsertPoint(CheckTerm);
1562  Value *Cmp2 = createSlowPathCmp(IRB, AddrLong, ShadowValue, TypeSize);
1563  if (Recover) {
1564  CrashTerm = SplitBlockAndInsertIfThen(Cmp2, CheckTerm, false);
1565  } else {
1566  BasicBlock *CrashBlock =
1567  BasicBlock::Create(*C, "", NextBB->getParent(), NextBB);
1568  CrashTerm = new UnreachableInst(*C, CrashBlock);
1569  BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
1570  ReplaceInstWithInst(CheckTerm, NewTerm);
1571  }
1572  } else {
1573  CrashTerm = SplitBlockAndInsertIfThen(Cmp, InsertBefore, !Recover);
1574  }
1575 
1576  Instruction *Crash = generateCrashCode(CrashTerm, AddrLong, IsWrite,
1577  AccessSizeIndex, SizeArgument, Exp);
1578  Crash->setDebugLoc(OrigIns->getDebugLoc());
1579 }
1580 
1581 // Instrument unusual size or unusual alignment.
1582 // We can not do it with a single check, so we do 1-byte check for the first
1583 // and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
1584 // to report the actual access size.
1585 void AddressSanitizer::instrumentUnusualSizeOrAlignment(
1586  Instruction *I, Instruction *InsertBefore, Value *Addr, uint32_t TypeSize,
1587  bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp) {
1588  IRBuilder<> IRB(InsertBefore);
1589  Value *Size = ConstantInt::get(IntptrTy, TypeSize / 8);
1590  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1591  if (UseCalls) {
1592  if (Exp == 0)
1593  IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][0],
1594  {AddrLong, Size});
1595  else
1596  IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][1],
1597  {AddrLong, Size, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1598  } else {
1599  Value *LastByte = IRB.CreateIntToPtr(
1600  IRB.CreateAdd(AddrLong, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
1601  Addr->getType());
1602  instrumentAddress(I, InsertBefore, Addr, 8, IsWrite, Size, false, Exp);
1603  instrumentAddress(I, InsertBefore, LastByte, 8, IsWrite, Size, false, Exp);
1604  }
1605 }
1606 
1607 void AddressSanitizerModule::poisonOneInitializer(Function &GlobalInit,
1608  GlobalValue *ModuleName) {
1609  // Set up the arguments to our poison/unpoison functions.
1610  IRBuilder<> IRB(&GlobalInit.front(),
1611  GlobalInit.front().getFirstInsertionPt());
1612 
1613  // Add a call to poison all external globals before the given function starts.
1614  Value *ModuleNameAddr = ConstantExpr::getPointerCast(ModuleName, IntptrTy);
1615  IRB.CreateCall(AsanPoisonGlobals, ModuleNameAddr);
1616 
1617  // Add calls to unpoison all globals before each return instruction.
1618  for (auto &BB : GlobalInit.getBasicBlockList())
1619  if (ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator()))
1620  CallInst::Create(AsanUnpoisonGlobals, "", RI);
1621 }
1622 
1623 void AddressSanitizerModule::createInitializerPoisonCalls(
1624  Module &M, GlobalValue *ModuleName) {
1625  GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
1626  if (!GV)
1627  return;
1628 
1630  if (!CA)
1631  return;
1632 
1633  for (Use &OP : CA->operands()) {
1634  if (isa<ConstantAggregateZero>(OP)) continue;
1635  ConstantStruct *CS = cast<ConstantStruct>(OP);
1636 
1637  // Must have a function or null ptr.
1638  if (Function *F = dyn_cast<Function>(CS->getOperand(1))) {
1639  if (F->getName() == kAsanModuleCtorName) continue;
1640  ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1641  // Don't instrument CTORs that will run before asan.module_ctor.
1642  if (Priority->getLimitedValue() <= kAsanCtorAndDtorPriority) continue;
1643  poisonOneInitializer(*F, ModuleName);
1644  }
1645  }
1646 }
1647 
1648 bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
1649  Type *Ty = G->getValueType();
1650  LLVM_DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
1651 
1652  if (GlobalsMD.get(G).IsBlacklisted) return false;
1653  if (!Ty->isSized()) return false;
1654  if (!G->hasInitializer()) return false;
1655  if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
1656  // Touch only those globals that will not be defined in other modules.
1657  // Don't handle ODR linkage types and COMDATs since other modules may be built
1658  // without ASan.
1662  return false;
1663  if (G->hasComdat()) return false;
1664  // Two problems with thread-locals:
1665  // - The address of the main thread's copy can't be computed at link-time.
1666  // - Need to poison all copies, not just the main thread's one.
1667  if (G->isThreadLocal()) return false;
1668  // For now, just ignore this Global if the alignment is large.
1669  if (G->getAlignment() > MinRedzoneSizeForGlobal()) return false;
1670 
1671  if (G->hasSection()) {
1672  StringRef Section = G->getSection();
1673 
1674  // Globals from llvm.metadata aren't emitted, do not instrument them.
1675  if (Section == "llvm.metadata") return false;
1676  // Do not instrument globals from special LLVM sections.
1677  if (Section.find("__llvm") != StringRef::npos || Section.find("__LLVM") != StringRef::npos) return false;
1678 
1679  // Do not instrument function pointers to initialization and termination
1680  // routines: dynamic linker will not properly handle redzones.
1681  if (Section.startswith(".preinit_array") ||
1682  Section.startswith(".init_array") ||
1683  Section.startswith(".fini_array")) {
1684  return false;
1685  }
1686 
1687  // On COFF, if the section name contains '$', it is highly likely that the
1688  // user is using section sorting to create an array of globals similar to
1689  // the way initialization callbacks are registered in .init_array and
1690  // .CRT$XCU. The ATL also registers things in .ATL$__[azm]. Adding redzones
1691  // to such globals is counterproductive, because the intent is that they
1692  // will form an array, and out-of-bounds accesses are expected.
1693  // See https://github.com/google/sanitizers/issues/305
1694  // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
1695  if (TargetTriple.isOSBinFormatCOFF() && Section.contains('$')) {
1696  LLVM_DEBUG(dbgs() << "Ignoring global in sorted section (contains '$'): "
1697  << *G << "\n");
1698  return false;
1699  }
1700 
1701  if (TargetTriple.isOSBinFormatMachO()) {
1702  StringRef ParsedSegment, ParsedSection;
1703  unsigned TAA = 0, StubSize = 0;
1704  bool TAAParsed;
1705  std::string ErrorCode = MCSectionMachO::ParseSectionSpecifier(
1706  Section, ParsedSegment, ParsedSection, TAA, TAAParsed, StubSize);
1707  assert(ErrorCode.empty() && "Invalid section specifier.");
1708 
1709  // Ignore the globals from the __OBJC section. The ObjC runtime assumes
1710  // those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
1711  // them.
1712  if (ParsedSegment == "__OBJC" ||
1713  (ParsedSegment == "__DATA" && ParsedSection.startswith("__objc_"))) {
1714  LLVM_DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G << "\n");
1715  return false;
1716  }
1717  // See https://github.com/google/sanitizers/issues/32
1718  // Constant CFString instances are compiled in the following way:
1719  // -- the string buffer is emitted into
1720  // __TEXT,__cstring,cstring_literals
1721  // -- the constant NSConstantString structure referencing that buffer
1722  // is placed into __DATA,__cfstring
1723  // Therefore there's no point in placing redzones into __DATA,__cfstring.
1724  // Moreover, it causes the linker to crash on OS X 10.7
1725  if (ParsedSegment == "__DATA" && ParsedSection == "__cfstring") {
1726  LLVM_DEBUG(dbgs() << "Ignoring CFString: " << *G << "\n");
1727  return false;
1728  }
1729  // The linker merges the contents of cstring_literals and removes the
1730  // trailing zeroes.
1731  if (ParsedSegment == "__TEXT" && (TAA & MachO::S_CSTRING_LITERALS)) {
1732  LLVM_DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n");
1733  return false;
1734  }
1735  }
1736  }
1737 
1738  return true;
1739 }
1740 
1741 // On Mach-O platforms, we emit global metadata in a separate section of the
1742 // binary in order to allow the linker to properly dead strip. This is only
1743 // supported on recent versions of ld64.
1744 bool AddressSanitizerModule::ShouldUseMachOGlobalsSection() const {
1745  if (!TargetTriple.isOSBinFormatMachO())
1746  return false;
1747 
1748  if (TargetTriple.isMacOSX() && !TargetTriple.isMacOSXVersionLT(10, 11))
1749  return true;
1750  if (TargetTriple.isiOS() /* or tvOS */ && !TargetTriple.isOSVersionLT(9))
1751  return true;
1752  if (TargetTriple.isWatchOS() && !TargetTriple.isOSVersionLT(2))
1753  return true;
1754 
1755  return false;
1756 }
1757 
1758 StringRef AddressSanitizerModule::getGlobalMetadataSection() const {
1759  switch (TargetTriple.getObjectFormat()) {
1760  case Triple::COFF: return ".ASAN$GL";
1761  case Triple::ELF: return "asan_globals";
1762  case Triple::MachO: return "__DATA,__asan_globals,regular";
1763  default: break;
1764  }
1765  llvm_unreachable("unsupported object format");
1766 }
1767 
1768 void AddressSanitizerModule::initializeCallbacks(Module &M) {
1769  IRBuilder<> IRB(*C);
1770 
1771  // Declare our poisoning and unpoisoning functions.
1773  kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy));
1774  AsanPoisonGlobals->setLinkage(Function::ExternalLinkage);
1775  AsanUnpoisonGlobals = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
1776  kAsanUnpoisonGlobalsName, IRB.getVoidTy()));
1777  AsanUnpoisonGlobals->setLinkage(Function::ExternalLinkage);
1778 
1779  // Declare functions that register/unregister globals.
1780  AsanRegisterGlobals = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
1781  kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy));
1782  AsanRegisterGlobals->setLinkage(Function::ExternalLinkage);
1783  AsanUnregisterGlobals = checkSanitizerInterfaceFunction(
1784  M.getOrInsertFunction(kAsanUnregisterGlobalsName, IRB.getVoidTy(),
1785  IntptrTy, IntptrTy));
1786  AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
1787 
1788  // Declare the functions that find globals in a shared object and then invoke
1789  // the (un)register function on them.
1790  AsanRegisterImageGlobals =
1792  kAsanRegisterImageGlobalsName, IRB.getVoidTy(), IntptrTy));
1793  AsanRegisterImageGlobals->setLinkage(Function::ExternalLinkage);
1794 
1795  AsanUnregisterImageGlobals =
1797  kAsanUnregisterImageGlobalsName, IRB.getVoidTy(), IntptrTy));
1798  AsanUnregisterImageGlobals->setLinkage(Function::ExternalLinkage);
1799 
1800  AsanRegisterElfGlobals = checkSanitizerInterfaceFunction(
1801  M.getOrInsertFunction(kAsanRegisterElfGlobalsName, IRB.getVoidTy(),
1802  IntptrTy, IntptrTy, IntptrTy));
1803  AsanRegisterElfGlobals->setLinkage(Function::ExternalLinkage);
1804 
1805  AsanUnregisterElfGlobals = checkSanitizerInterfaceFunction(
1806  M.getOrInsertFunction(kAsanUnregisterElfGlobalsName, IRB.getVoidTy(),
1807  IntptrTy, IntptrTy, IntptrTy));
1808  AsanUnregisterElfGlobals->setLinkage(Function::ExternalLinkage);
1809 }
1810 
1811 // Put the metadata and the instrumented global in the same group. This ensures
1812 // that the metadata is discarded if the instrumented global is discarded.
1813 void AddressSanitizerModule::SetComdatForGlobalMetadata(
1814  GlobalVariable *G, GlobalVariable *Metadata, StringRef InternalSuffix) {
1815  Module &M = *G->getParent();
1816  Comdat *C = G->getComdat();
1817  if (!C) {
1818  if (!G->hasName()) {
1819  // If G is unnamed, it must be internal. Give it an artificial name
1820  // so we can put it in a comdat.
1821  assert(G->hasLocalLinkage());
1822  G->setName(Twine(kAsanGenPrefix) + "_anon_global");
1823  }
1824 
1825  if (!InternalSuffix.empty() && G->hasLocalLinkage()) {
1826  std::string Name = G->getName();
1827  Name += InternalSuffix;
1828  C = M.getOrInsertComdat(Name);
1829  } else {
1830  C = M.getOrInsertComdat(G->getName());
1831  }
1832 
1833  // Make this IMAGE_COMDAT_SELECT_NODUPLICATES on COFF. Also upgrade private
1834  // linkage to internal linkage so that a symbol table entry is emitted. This
1835  // is necessary in order to create the comdat group.
1836  if (TargetTriple.isOSBinFormatCOFF()) {
1838  if (G->hasPrivateLinkage())
1840  }
1841  G->setComdat(C);
1842  }
1843 
1844  assert(G->hasComdat());
1845  Metadata->setComdat(G->getComdat());
1846 }
1847 
1848 // Create a separate metadata global and put it in the appropriate ASan
1849 // global registration section.
1851 AddressSanitizerModule::CreateMetadataGlobal(Module &M, Constant *Initializer,
1852  StringRef OriginalName) {
1853  auto Linkage = TargetTriple.isOSBinFormatMachO()
1856  GlobalVariable *Metadata = new GlobalVariable(
1857  M, Initializer->getType(), false, Linkage, Initializer,
1858  Twine("__asan_global_") + GlobalValue::dropLLVMManglingEscape(OriginalName));
1859  Metadata->setSection(getGlobalMetadataSection());
1860  return Metadata;
1861 }
1862 
1863 IRBuilder<> AddressSanitizerModule::CreateAsanModuleDtor(Module &M) {
1864  AsanDtorFunction =
1866  GlobalValue::InternalLinkage, kAsanModuleDtorName, &M);
1867  BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
1868 
1869  return IRBuilder<>(ReturnInst::Create(*C, AsanDtorBB));
1870 }
1871 
1872 void AddressSanitizerModule::InstrumentGlobalsCOFF(
1873  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
1874  ArrayRef<Constant *> MetadataInitializers) {
1875  assert(ExtendedGlobals.size() == MetadataInitializers.size());
1876  auto &DL = M.getDataLayout();
1877 
1878  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
1879  Constant *Initializer = MetadataInitializers[i];
1880  GlobalVariable *G = ExtendedGlobals[i];
1881  GlobalVariable *Metadata =
1882  CreateMetadataGlobal(M, Initializer, G->getName());
1883 
1884  // The MSVC linker always inserts padding when linking incrementally. We
1885  // cope with that by aligning each struct to its size, which must be a power
1886  // of two.
1887  unsigned SizeOfGlobalStruct = DL.getTypeAllocSize(Initializer->getType());
1888  assert(isPowerOf2_32(SizeOfGlobalStruct) &&
1889  "global metadata will not be padded appropriately");
1890  Metadata->setAlignment(SizeOfGlobalStruct);
1891 
1892  SetComdatForGlobalMetadata(G, Metadata, "");
1893  }
1894 }
1895 
1896 void AddressSanitizerModule::InstrumentGlobalsELF(
1897  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
1898  ArrayRef<Constant *> MetadataInitializers,
1899  const std::string &UniqueModuleId) {
1900  assert(ExtendedGlobals.size() == MetadataInitializers.size());
1901 
1902  SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
1903  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
1904  GlobalVariable *G = ExtendedGlobals[i];
1905  GlobalVariable *Metadata =
1906  CreateMetadataGlobal(M, MetadataInitializers[i], G->getName());
1908  Metadata->setMetadata(LLVMContext::MD_associated, MD);
1909  MetadataGlobals[i] = Metadata;
1910 
1911  SetComdatForGlobalMetadata(G, Metadata, UniqueModuleId);
1912  }
1913 
1914  // Update llvm.compiler.used, adding the new metadata globals. This is
1915  // needed so that during LTO these variables stay alive.
1916  if (!MetadataGlobals.empty())
1917  appendToCompilerUsed(M, MetadataGlobals);
1918 
1919  // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
1920  // to look up the loaded image that contains it. Second, we can store in it
1921  // whether registration has already occurred, to prevent duplicate
1922  // registration.
1923  //
1924  // Common linkage ensures that there is only one global per shared library.
1925  GlobalVariable *RegisteredFlag = new GlobalVariable(
1926  M, IntptrTy, false, GlobalVariable::CommonLinkage,
1927  ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
1929 
1930  // Create start and stop symbols.
1931  GlobalVariable *StartELFMetadata = new GlobalVariable(
1932  M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
1933  "__start_" + getGlobalMetadataSection());
1935  GlobalVariable *StopELFMetadata = new GlobalVariable(
1936  M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
1937  "__stop_" + getGlobalMetadataSection());
1939 
1940  // Create a call to register the globals with the runtime.
1941  IRB.CreateCall(AsanRegisterElfGlobals,
1942  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
1943  IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
1944  IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
1945 
1946  // We also need to unregister globals at the end, e.g., when a shared library
1947  // gets closed.
1948  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
1949  IRB_Dtor.CreateCall(AsanUnregisterElfGlobals,
1950  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
1951  IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
1952  IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
1953 }
1954 
1955 void AddressSanitizerModule::InstrumentGlobalsMachO(
1956  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
1957  ArrayRef<Constant *> MetadataInitializers) {
1958  assert(ExtendedGlobals.size() == MetadataInitializers.size());
1959 
1960  // On recent Mach-O platforms, use a structure which binds the liveness of
1961  // the global variable to the metadata struct. Keep the list of "Liveness" GV
1962  // created to be added to llvm.compiler.used
1963  StructType *LivenessTy = StructType::get(IntptrTy, IntptrTy);
1964  SmallVector<GlobalValue *, 16> LivenessGlobals(ExtendedGlobals.size());
1965 
1966  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
1967  Constant *Initializer = MetadataInitializers[i];
1968  GlobalVariable *G = ExtendedGlobals[i];
1969  GlobalVariable *Metadata =
1970  CreateMetadataGlobal(M, Initializer, G->getName());
1971 
1972  // On recent Mach-O platforms, we emit the global metadata in a way that
1973  // allows the linker to properly strip dead globals.
1974  auto LivenessBinder =
1975  ConstantStruct::get(LivenessTy, Initializer->getAggregateElement(0u),
1976  ConstantExpr::getPointerCast(Metadata, IntptrTy));
1977  GlobalVariable *Liveness = new GlobalVariable(
1978  M, LivenessTy, false, GlobalVariable::InternalLinkage, LivenessBinder,
1979  Twine("__asan_binder_") + G->getName());
1980  Liveness->setSection("__DATA,__asan_liveness,regular,live_support");
1981  LivenessGlobals[i] = Liveness;
1982  }
1983 
1984  // Update llvm.compiler.used, adding the new liveness globals. This is
1985  // needed so that during LTO these variables stay alive. The alternative
1986  // would be to have the linker handling the LTO symbols, but libLTO
1987  // current API does not expose access to the section for each symbol.
1988  if (!LivenessGlobals.empty())
1989  appendToCompilerUsed(M, LivenessGlobals);
1990 
1991  // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
1992  // to look up the loaded image that contains it. Second, we can store in it
1993  // whether registration has already occurred, to prevent duplicate
1994  // registration.
1995  //
1996  // common linkage ensures that there is only one global per shared library.
1997  GlobalVariable *RegisteredFlag = new GlobalVariable(
1998  M, IntptrTy, false, GlobalVariable::CommonLinkage,
1999  ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
2001 
2002  IRB.CreateCall(AsanRegisterImageGlobals,
2003  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2004 
2005  // We also need to unregister globals at the end, e.g., when a shared library
2006  // gets closed.
2007  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2008  IRB_Dtor.CreateCall(AsanUnregisterImageGlobals,
2009  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2010 }
2011 
2012 void AddressSanitizerModule::InstrumentGlobalsWithMetadataArray(
2013  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2014  ArrayRef<Constant *> MetadataInitializers) {
2015  assert(ExtendedGlobals.size() == MetadataInitializers.size());
2016  unsigned N = ExtendedGlobals.size();
2017  assert(N > 0);
2018 
2019  // On platforms that don't have a custom metadata section, we emit an array
2020  // of global metadata structures.
2021  ArrayType *ArrayOfGlobalStructTy =
2022  ArrayType::get(MetadataInitializers[0]->getType(), N);
2023  auto AllGlobals = new GlobalVariable(
2024  M, ArrayOfGlobalStructTy, false, GlobalVariable::InternalLinkage,
2025  ConstantArray::get(ArrayOfGlobalStructTy, MetadataInitializers), "");
2026  if (Mapping.Scale > 3)
2027  AllGlobals->setAlignment(1ULL << Mapping.Scale);
2028 
2029  IRB.CreateCall(AsanRegisterGlobals,
2030  {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2031  ConstantInt::get(IntptrTy, N)});
2032 
2033  // We also need to unregister globals at the end, e.g., when a shared library
2034  // gets closed.
2035  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2036  IRB_Dtor.CreateCall(AsanUnregisterGlobals,
2037  {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2038  ConstantInt::get(IntptrTy, N)});
2039 }
2040 
2041 // This function replaces all global variables with new variables that have
2042 // trailing redzones. It also creates a function that poisons
2043 // redzones and inserts this function into llvm.global_ctors.
2044 // Sets *CtorComdat to true if the global registration code emitted into the
2045 // asan constructor is comdat-compatible.
2046 bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat) {
2047  *CtorComdat = false;
2048  GlobalsMD.init(M);
2049 
2050  SmallVector<GlobalVariable *, 16> GlobalsToChange;
2051 
2052  for (auto &G : M.globals()) {
2053  if (ShouldInstrumentGlobal(&G)) GlobalsToChange.push_back(&G);
2054  }
2055 
2056  size_t n = GlobalsToChange.size();
2057  if (n == 0) {
2058  *CtorComdat = true;
2059  return false;
2060  }
2061 
2062  auto &DL = M.getDataLayout();
2063 
2064  // A global is described by a structure
2065  // size_t beg;
2066  // size_t size;
2067  // size_t size_with_redzone;
2068  // const char *name;
2069  // const char *module_name;
2070  // size_t has_dynamic_init;
2071  // void *source_location;
2072  // size_t odr_indicator;
2073  // We initialize an array of such structures and pass it to a run-time call.
2074  StructType *GlobalStructTy =
2075  StructType::get(IntptrTy, IntptrTy, IntptrTy, IntptrTy, IntptrTy,
2076  IntptrTy, IntptrTy, IntptrTy);
2077  SmallVector<GlobalVariable *, 16> NewGlobals(n);
2078  SmallVector<Constant *, 16> Initializers(n);
2079 
2080  bool HasDynamicallyInitializedGlobals = false;
2081 
2082  // We shouldn't merge same module names, as this string serves as unique
2083  // module ID in runtime.
2085  M, M.getModuleIdentifier(), /*AllowMerging*/ false);
2086 
2087  for (size_t i = 0; i < n; i++) {
2088  static const uint64_t kMaxGlobalRedzone = 1 << 18;
2089  GlobalVariable *G = GlobalsToChange[i];
2090 
2091  auto MD = GlobalsMD.get(G);
2092  StringRef NameForGlobal = G->getName();
2093  // Create string holding the global name (use global name from metadata
2094  // if it's available, otherwise just write the name of global variable).
2096  M, MD.Name.empty() ? NameForGlobal : MD.Name,
2097  /*AllowMerging*/ true);
2098 
2099  Type *Ty = G->getValueType();
2100  uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
2101  uint64_t MinRZ = MinRedzoneSizeForGlobal();
2102  // MinRZ <= RZ <= kMaxGlobalRedzone
2103  // and trying to make RZ to be ~ 1/4 of SizeInBytes.
2104  uint64_t RZ = std::max(
2105  MinRZ, std::min(kMaxGlobalRedzone, (SizeInBytes / MinRZ / 4) * MinRZ));
2106  uint64_t RightRedzoneSize = RZ;
2107  // Round up to MinRZ
2108  if (SizeInBytes % MinRZ) RightRedzoneSize += MinRZ - (SizeInBytes % MinRZ);
2109  assert(((RightRedzoneSize + SizeInBytes) % MinRZ) == 0);
2110  Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
2111 
2112  StructType *NewTy = StructType::get(Ty, RightRedZoneTy);
2113  Constant *NewInitializer = ConstantStruct::get(
2114  NewTy, G->getInitializer(), Constant::getNullValue(RightRedZoneTy));
2115 
2116  // Create a new global variable with enough space for a redzone.
2117  GlobalValue::LinkageTypes Linkage = G->getLinkage();
2118  if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
2119  Linkage = GlobalValue::InternalLinkage;
2120  GlobalVariable *NewGlobal =
2121  new GlobalVariable(M, NewTy, G->isConstant(), Linkage, NewInitializer,
2122  "", G, G->getThreadLocalMode());
2123  NewGlobal->copyAttributesFrom(G);
2124  NewGlobal->setAlignment(MinRZ);
2125 
2126  // Move null-terminated C strings to "__asan_cstring" section on Darwin.
2127  if (TargetTriple.isOSBinFormatMachO() && !G->hasSection() &&
2128  G->isConstant()) {
2129  auto Seq = dyn_cast<ConstantDataSequential>(G->getInitializer());
2130  if (Seq && Seq->isCString())
2131  NewGlobal->setSection("__TEXT,__asan_cstring,regular");
2132  }
2133 
2134  // Transfer the debug info. The payload starts at offset zero so we can
2135  // copy the debug info over as is.
2137  G->getDebugInfo(GVs);
2138  for (auto *GV : GVs)
2139  NewGlobal->addDebugInfo(GV);
2140 
2141  Value *Indices2[2];
2142  Indices2[0] = IRB.getInt32(0);
2143  Indices2[1] = IRB.getInt32(0);
2144 
2145  G->replaceAllUsesWith(
2146  ConstantExpr::getGetElementPtr(NewTy, NewGlobal, Indices2, true));
2147  NewGlobal->takeName(G);
2148  G->eraseFromParent();
2149  NewGlobals[i] = NewGlobal;
2150 
2151  Constant *SourceLoc;
2152  if (!MD.SourceLoc.empty()) {
2153  auto SourceLocGlobal = createPrivateGlobalForSourceLoc(M, MD.SourceLoc);
2154  SourceLoc = ConstantExpr::getPointerCast(SourceLocGlobal, IntptrTy);
2155  } else {
2156  SourceLoc = ConstantInt::get(IntptrTy, 0);
2157  }
2158 
2159  Constant *ODRIndicator = ConstantExpr::getNullValue(IRB.getInt8PtrTy());
2160  GlobalValue *InstrumentedGlobal = NewGlobal;
2161 
2162  bool CanUsePrivateAliases =
2163  TargetTriple.isOSBinFormatELF() || TargetTriple.isOSBinFormatMachO() ||
2164  TargetTriple.isOSBinFormatWasm();
2165  if (CanUsePrivateAliases && ClUsePrivateAliasForGlobals) {
2166  // Create local alias for NewGlobal to avoid crash on ODR between
2167  // instrumented and non-instrumented libraries.
2169  NameForGlobal + M.getName(), NewGlobal);
2170 
2171  // With local aliases, we need to provide another externally visible
2172  // symbol __odr_asan_XXX to detect ODR violation.
2173  auto *ODRIndicatorSym =
2174  new GlobalVariable(M, IRB.getInt8Ty(), false, Linkage,
2176  kODRGenPrefix + NameForGlobal, nullptr,
2177  NewGlobal->getThreadLocalMode());
2178 
2179  // Set meaningful attributes for indicator symbol.
2180  ODRIndicatorSym->setVisibility(NewGlobal->getVisibility());
2181  ODRIndicatorSym->setDLLStorageClass(NewGlobal->getDLLStorageClass());
2182  ODRIndicatorSym->setAlignment(1);
2183  ODRIndicator = ODRIndicatorSym;
2184  InstrumentedGlobal = GA;
2185  }
2186 
2187  Constant *Initializer = ConstantStruct::get(
2188  GlobalStructTy,
2189  ConstantExpr::getPointerCast(InstrumentedGlobal, IntptrTy),
2190  ConstantInt::get(IntptrTy, SizeInBytes),
2191  ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
2192  ConstantExpr::getPointerCast(Name, IntptrTy),
2193  ConstantExpr::getPointerCast(ModuleName, IntptrTy),
2194  ConstantInt::get(IntptrTy, MD.IsDynInit), SourceLoc,
2195  ConstantExpr::getPointerCast(ODRIndicator, IntptrTy));
2196 
2197  if (ClInitializers && MD.IsDynInit) HasDynamicallyInitializedGlobals = true;
2198 
2199  LLVM_DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
2200 
2201  Initializers[i] = Initializer;
2202  }
2203 
2204  // Add instrumented globals to llvm.compiler.used list to avoid LTO from
2205  // ConstantMerge'ing them.
2206  SmallVector<GlobalValue *, 16> GlobalsToAddToUsedList;
2207  for (size_t i = 0; i < n; i++) {
2208  GlobalVariable *G = NewGlobals[i];
2209  if (G->getName().empty()) continue;
2210  GlobalsToAddToUsedList.push_back(G);
2211  }
2212  appendToCompilerUsed(M, ArrayRef<GlobalValue *>(GlobalsToAddToUsedList));
2213 
2214  std::string ELFUniqueModuleId =
2215  (UseGlobalsGC && TargetTriple.isOSBinFormatELF()) ? getUniqueModuleId(&M)
2216  : "";
2217 
2218  if (!ELFUniqueModuleId.empty()) {
2219  InstrumentGlobalsELF(IRB, M, NewGlobals, Initializers, ELFUniqueModuleId);
2220  *CtorComdat = true;
2221  } else if (UseGlobalsGC && TargetTriple.isOSBinFormatCOFF()) {
2222  InstrumentGlobalsCOFF(IRB, M, NewGlobals, Initializers);
2223  } else if (UseGlobalsGC && ShouldUseMachOGlobalsSection()) {
2224  InstrumentGlobalsMachO(IRB, M, NewGlobals, Initializers);
2225  } else {
2226  InstrumentGlobalsWithMetadataArray(IRB, M, NewGlobals, Initializers);
2227  }
2228 
2229  // Create calls for poisoning before initializers run and unpoisoning after.
2230  if (HasDynamicallyInitializedGlobals)
2231  createInitializerPoisonCalls(M, ModuleName);
2232 
2233  LLVM_DEBUG(dbgs() << M);
2234  return true;
2235 }
2236 
2237 int AddressSanitizerModule::GetAsanVersion(const Module &M) const {
2238  int LongSize = M.getDataLayout().getPointerSizeInBits();
2239  bool isAndroid = Triple(M.getTargetTriple()).isAndroid();
2240  int Version = 8;
2241  // 32-bit Android is one version ahead because of the switch to dynamic
2242  // shadow.
2243  Version += (LongSize == 32 && isAndroid);
2244  return Version;
2245 }
2246 
2247 bool AddressSanitizerModule::runOnModule(Module &M) {
2248  C = &(M.getContext());
2249  int LongSize = M.getDataLayout().getPointerSizeInBits();
2250  IntptrTy = Type::getIntNTy(*C, LongSize);
2251  TargetTriple = Triple(M.getTargetTriple());
2252  Mapping = getShadowMapping(TargetTriple, LongSize, CompileKernel);
2253  initializeCallbacks(M);
2254 
2255  if (CompileKernel)
2256  return false;
2257 
2258  // Create a module constructor. A destructor is created lazily because not all
2259  // platforms, and not all modules need it.
2260  std::string VersionCheckName =
2261  kAsanVersionCheckNamePrefix + std::to_string(GetAsanVersion(M));
2262  std::tie(AsanCtorFunction, std::ignore) = createSanitizerCtorAndInitFunctions(
2263  M, kAsanModuleCtorName, kAsanInitName, /*InitArgTypes=*/{},
2264  /*InitArgs=*/{}, VersionCheckName);
2265 
2266  bool CtorComdat = true;
2267  bool Changed = false;
2268  // TODO(glider): temporarily disabled globals instrumentation for KASan.
2269  if (ClGlobals) {
2270  IRBuilder<> IRB(AsanCtorFunction->getEntryBlock().getTerminator());
2271  Changed |= InstrumentGlobals(IRB, M, &CtorComdat);
2272  }
2273 
2274  // Put the constructor and destructor in comdat if both
2275  // (1) global instrumentation is not TU-specific
2276  // (2) target is ELF.
2277  if (UseCtorComdat && TargetTriple.isOSBinFormatELF() && CtorComdat) {
2278  AsanCtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleCtorName));
2279  appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndDtorPriority,
2280  AsanCtorFunction);
2281  if (AsanDtorFunction) {
2282  AsanDtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleDtorName));
2283  appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndDtorPriority,
2284  AsanDtorFunction);
2285  }
2286  } else {
2287  appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndDtorPriority);
2288  if (AsanDtorFunction)
2289  appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndDtorPriority);
2290  }
2291 
2292  return Changed;
2293 }
2294 
2295 void AddressSanitizer::initializeCallbacks(Module &M) {
2296  IRBuilder<> IRB(*C);
2297  // Create __asan_report* callbacks.
2298  // IsWrite, TypeSize and Exp are encoded in the function name.
2299  for (int Exp = 0; Exp < 2; Exp++) {
2300  for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
2301  const std::string TypeStr = AccessIsWrite ? "store" : "load";
2302  const std::string ExpStr = Exp ? "exp_" : "";
2303  const std::string EndingStr = Recover ? "_noabort" : "";
2304 
2305  SmallVector<Type *, 3> Args2 = {IntptrTy, IntptrTy};
2306  SmallVector<Type *, 2> Args1{1, IntptrTy};
2307  if (Exp) {
2308  Type *ExpType = Type::getInt32Ty(*C);
2309  Args2.push_back(ExpType);
2310  Args1.push_back(ExpType);
2311  }
2312  AsanErrorCallbackSized[AccessIsWrite][Exp] =
2314  kAsanReportErrorTemplate + ExpStr + TypeStr + "_n" + EndingStr,
2315  FunctionType::get(IRB.getVoidTy(), Args2, false)));
2316 
2317  AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] =
2319  ClMemoryAccessCallbackPrefix + ExpStr + TypeStr + "N" + EndingStr,
2320  FunctionType::get(IRB.getVoidTy(), Args2, false)));
2321 
2322  for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
2323  AccessSizeIndex++) {
2324  const std::string Suffix = TypeStr + itostr(1ULL << AccessSizeIndex);
2325  AsanErrorCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2327  kAsanReportErrorTemplate + ExpStr + Suffix + EndingStr,
2328  FunctionType::get(IRB.getVoidTy(), Args1, false)));
2329 
2330  AsanMemoryAccessCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2332  ClMemoryAccessCallbackPrefix + ExpStr + Suffix + EndingStr,
2333  FunctionType::get(IRB.getVoidTy(), Args1, false)));
2334  }
2335  }
2336  }
2337 
2338  const std::string MemIntrinCallbackPrefix =
2339  CompileKernel ? std::string("") : ClMemoryAccessCallbackPrefix;
2341  MemIntrinCallbackPrefix + "memmove", IRB.getInt8PtrTy(),
2342  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy));
2344  MemIntrinCallbackPrefix + "memcpy", IRB.getInt8PtrTy(),
2345  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy));
2347  MemIntrinCallbackPrefix + "memset", IRB.getInt8PtrTy(),
2348  IRB.getInt8PtrTy(), IRB.getInt32Ty(), IntptrTy));
2349 
2350  AsanHandleNoReturnFunc = checkSanitizerInterfaceFunction(
2351  M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy()));
2352 
2354  kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy));
2356  kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy));
2357  // We insert an empty inline asm after __asan_report* to avoid callback merge.
2358  EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
2359  StringRef(""), StringRef(""),
2360  /*hasSideEffects=*/true);
2361  if (Mapping.InGlobal)
2362  AsanShadowGlobal = M.getOrInsertGlobal("__asan_shadow",
2363  ArrayType::get(IRB.getInt8Ty(), 0));
2364 }
2365 
2366 // virtual
2367 bool AddressSanitizer::doInitialization(Module &M) {
2368  // Initialize the private fields. No one has accessed them before.
2369  GlobalsMD.init(M);
2370 
2371  C = &(M.getContext());
2372  LongSize = M.getDataLayout().getPointerSizeInBits();
2373  IntptrTy = Type::getIntNTy(*C, LongSize);
2374  TargetTriple = Triple(M.getTargetTriple());
2375 
2376  Mapping = getShadowMapping(TargetTriple, LongSize, CompileKernel);
2377  return true;
2378 }
2379 
2380 bool AddressSanitizer::doFinalization(Module &M) {
2381  GlobalsMD.reset();
2382  return false;
2383 }
2384 
2385 bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
2386  // For each NSObject descendant having a +load method, this method is invoked
2387  // by the ObjC runtime before any of the static constructors is called.
2388  // Therefore we need to instrument such methods with a call to __asan_init
2389  // at the beginning in order to initialize our runtime before any access to
2390  // the shadow memory.
2391  // We cannot just ignore these methods, because they may call other
2392  // instrumented functions.
2393  if (F.getName().find(" load]") != std::string::npos) {
2394  Function *AsanInitFunction =
2396  IRBuilder<> IRB(&F.front(), F.front().begin());
2397  IRB.CreateCall(AsanInitFunction, {});
2398  return true;
2399  }
2400  return false;
2401 }
2402 
2403 void AddressSanitizer::maybeInsertDynamicShadowAtFunctionEntry(Function &F) {
2404  // Generate code only when dynamic addressing is needed.
2405  if (Mapping.Offset != kDynamicShadowSentinel)
2406  return;
2407 
2408  IRBuilder<> IRB(&F.front().front());
2409  if (Mapping.InGlobal) {
2411  // An empty inline asm with input reg == output reg.
2412  // An opaque pointer-to-int cast, basically.
2414  FunctionType::get(IntptrTy, {AsanShadowGlobal->getType()}, false),
2415  StringRef(""), StringRef("=r,0"),
2416  /*hasSideEffects=*/false);
2417  LocalDynamicShadow =
2418  IRB.CreateCall(Asm, {AsanShadowGlobal}, ".asan.shadow");
2419  } else {
2420  LocalDynamicShadow =
2421  IRB.CreatePointerCast(AsanShadowGlobal, IntptrTy, ".asan.shadow");
2422  }
2423  } else {
2424  Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
2425  kAsanShadowMemoryDynamicAddress, IntptrTy);
2426  LocalDynamicShadow = IRB.CreateLoad(GlobalDynamicAddress);
2427  }
2428 }
2429 
2430 void AddressSanitizer::markEscapedLocalAllocas(Function &F) {
2431  // Find the one possible call to llvm.localescape and pre-mark allocas passed
2432  // to it as uninteresting. This assumes we haven't started processing allocas
2433  // yet. This check is done up front because iterating the use list in
2434  // isInterestingAlloca would be algorithmically slower.
2435  assert(ProcessedAllocas.empty() && "must process localescape before allocas");
2436 
2437  // Try to get the declaration of llvm.localescape. If it's not in the module,
2438  // we can exit early.
2439  if (!F.getParent()->getFunction("llvm.localescape")) return;
2440 
2441  // Look for a call to llvm.localescape call in the entry block. It can't be in
2442  // any other block.
2443  for (Instruction &I : F.getEntryBlock()) {
2445  if (II && II->getIntrinsicID() == Intrinsic::localescape) {
2446  // We found a call. Mark all the allocas passed in as uninteresting.
2447  for (Value *Arg : II->arg_operands()) {
2449  assert(AI && AI->isStaticAlloca() &&
2450  "non-static alloca arg to localescape");
2451  ProcessedAllocas[AI] = false;
2452  }
2453  break;
2454  }
2455  }
2456 }
2457 
2459  if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
2460  if (!ClDebugFunc.empty() && ClDebugFunc == F.getName()) return false;
2461  if (F.getName().startswith("__asan_")) return false;
2462 
2463  bool FunctionModified = false;
2464 
2465  // If needed, insert __asan_init before checking for SanitizeAddress attr.
2466  // This function needs to be called even if the function body is not
2467  // instrumented.
2468  if (maybeInsertAsanInitAtFunctionEntry(F))
2469  FunctionModified = true;
2470 
2471  // Leave if the function doesn't need instrumentation.
2472  if (!F.hasFnAttribute(Attribute::SanitizeAddress)) return FunctionModified;
2473 
2474  LLVM_DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
2475 
2476  initializeCallbacks(*F.getParent());
2477  DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
2478 
2479  FunctionStateRAII CleanupObj(this);
2480 
2481  maybeInsertDynamicShadowAtFunctionEntry(F);
2482 
2483  // We can't instrument allocas used with llvm.localescape. Only static allocas
2484  // can be passed to that intrinsic.
2485  markEscapedLocalAllocas(F);
2486 
2487  // We want to instrument every address only once per basic block (unless there
2488  // are calls between uses).
2489  SmallPtrSet<Value *, 16> TempsToInstrument;
2490  SmallVector<Instruction *, 16> ToInstrument;
2491  SmallVector<Instruction *, 8> NoReturnCalls;
2493  SmallVector<Instruction *, 16> PointerComparisonsOrSubtracts;
2494  int NumAllocas = 0;
2495  bool IsWrite;
2496  unsigned Alignment;
2497  uint64_t TypeSize;
2498  const TargetLibraryInfo *TLI =
2499  &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
2500 
2501  // Fill the set of memory operations to instrument.
2502  for (auto &BB : F) {
2503  AllBlocks.push_back(&BB);
2504  TempsToInstrument.clear();
2505  int NumInsnsPerBB = 0;
2506  for (auto &Inst : BB) {
2507  if (LooksLikeCodeInBug11395(&Inst)) return false;
2508  Value *MaybeMask = nullptr;
2509  if (Value *Addr = isInterestingMemoryAccess(&Inst, &IsWrite, &TypeSize,
2510  &Alignment, &MaybeMask)) {
2511  if (ClOpt && ClOptSameTemp) {
2512  // If we have a mask, skip instrumentation if we've already
2513  // instrumented the full object. But don't add to TempsToInstrument
2514  // because we might get another load/store with a different mask.
2515  if (MaybeMask) {
2516  if (TempsToInstrument.count(Addr))
2517  continue; // We've seen this (whole) temp in the current BB.
2518  } else {
2519  if (!TempsToInstrument.insert(Addr).second)
2520  continue; // We've seen this temp in the current BB.
2521  }
2522  }
2523  } else if (ClInvalidPointerPairs &&
2525  PointerComparisonsOrSubtracts.push_back(&Inst);
2526  continue;
2527  } else if (isa<MemIntrinsic>(Inst)) {
2528  // ok, take it.
2529  } else {
2530  if (isa<AllocaInst>(Inst)) NumAllocas++;
2531  CallSite CS(&Inst);
2532  if (CS) {
2533  // A call inside BB.
2534  TempsToInstrument.clear();
2535  if (CS.doesNotReturn()) NoReturnCalls.push_back(CS.getInstruction());
2536  }
2537  if (CallInst *CI = dyn_cast<CallInst>(&Inst))
2539  continue;
2540  }
2541  ToInstrument.push_back(&Inst);
2542  NumInsnsPerBB++;
2543  if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB) break;
2544  }
2545  }
2546 
2547  bool UseCalls =
2550  const DataLayout &DL = F.getParent()->getDataLayout();
2551  ObjectSizeOpts ObjSizeOpts;
2552  ObjSizeOpts.RoundToAlign = true;
2553  ObjectSizeOffsetVisitor ObjSizeVis(DL, TLI, F.getContext(), ObjSizeOpts);
2554 
2555  // Instrument.
2556  int NumInstrumented = 0;
2557  for (auto Inst : ToInstrument) {
2558  if (ClDebugMin < 0 || ClDebugMax < 0 ||
2559  (NumInstrumented >= ClDebugMin && NumInstrumented <= ClDebugMax)) {
2560  if (isInterestingMemoryAccess(Inst, &IsWrite, &TypeSize, &Alignment))
2561  instrumentMop(ObjSizeVis, Inst, UseCalls,
2562  F.getParent()->getDataLayout());
2563  else
2564  instrumentMemIntrinsic(cast<MemIntrinsic>(Inst));
2565  }
2566  NumInstrumented++;
2567  }
2568 
2569  FunctionStackPoisoner FSP(F, *this);
2570  bool ChangedStack = FSP.runOnFunction();
2571 
2572  // We must unpoison the stack before every NoReturn call (throw, _exit, etc).
2573  // See e.g. https://github.com/google/sanitizers/issues/37
2574  for (auto CI : NoReturnCalls) {
2575  IRBuilder<> IRB(CI);
2576  IRB.CreateCall(AsanHandleNoReturnFunc, {});
2577  }
2578 
2579  for (auto Inst : PointerComparisonsOrSubtracts) {
2580  instrumentPointerComparisonOrSubtraction(Inst);
2581  NumInstrumented++;
2582  }
2583 
2584  if (NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty())
2585  FunctionModified = true;
2586 
2587  LLVM_DEBUG(dbgs() << "ASAN done instrumenting: " << FunctionModified << " "
2588  << F << "\n");
2589 
2590  return FunctionModified;
2591 }
2592 
2593 // Workaround for bug 11395: we don't want to instrument stack in functions
2594 // with large assembly blobs (32-bit only), otherwise reg alloc may crash.
2595 // FIXME: remove once the bug 11395 is fixed.
2596 bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
2597  if (LongSize != 32) return false;
2598  CallInst *CI = dyn_cast<CallInst>(I);
2599  if (!CI || !CI->isInlineAsm()) return false;
2600  if (CI->getNumArgOperands() <= 5) return false;
2601  // We have inline assembly with quite a few arguments.
2602  return true;
2603 }
2604 
2605 void FunctionStackPoisoner::initializeCallbacks(Module &M) {
2606  IRBuilder<> IRB(*C);
2607  for (int i = 0; i <= kMaxAsanStackMallocSizeClass; i++) {
2608  std::string Suffix = itostr(i);
2609  AsanStackMallocFunc[i] = checkSanitizerInterfaceFunction(
2610  M.getOrInsertFunction(kAsanStackMallocNameTemplate + Suffix, IntptrTy,
2611  IntptrTy));
2612  AsanStackFreeFunc[i] = checkSanitizerInterfaceFunction(
2613  M.getOrInsertFunction(kAsanStackFreeNameTemplate + Suffix,
2614  IRB.getVoidTy(), IntptrTy, IntptrTy));
2615  }
2616  if (ASan.UseAfterScope) {
2617  AsanPoisonStackMemoryFunc = checkSanitizerInterfaceFunction(
2618  M.getOrInsertFunction(kAsanPoisonStackMemoryName, IRB.getVoidTy(),
2619  IntptrTy, IntptrTy));
2620  AsanUnpoisonStackMemoryFunc = checkSanitizerInterfaceFunction(
2621  M.getOrInsertFunction(kAsanUnpoisonStackMemoryName, IRB.getVoidTy(),
2622  IntptrTy, IntptrTy));
2623  }
2624 
2625  for (size_t Val : {0x00, 0xf1, 0xf2, 0xf3, 0xf5, 0xf8}) {
2626  std::ostringstream Name;
2627  Name << kAsanSetShadowPrefix;
2628  Name << std::setw(2) << std::setfill('0') << std::hex << Val;
2629  AsanSetShadowFunc[Val] =
2631  Name.str(), IRB.getVoidTy(), IntptrTy, IntptrTy));
2632  }
2633 
2634  AsanAllocaPoisonFunc = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
2635  kAsanAllocaPoison, IRB.getVoidTy(), IntptrTy, IntptrTy));
2636  AsanAllocasUnpoisonFunc =
2638  kAsanAllocasUnpoison, IRB.getVoidTy(), IntptrTy, IntptrTy));
2639 }
2640 
2641 void FunctionStackPoisoner::copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
2642  ArrayRef<uint8_t> ShadowBytes,
2643  size_t Begin, size_t End,
2644  IRBuilder<> &IRB,
2645  Value *ShadowBase) {
2646  if (Begin >= End)
2647  return;
2648 
2649  const size_t LargestStoreSizeInBytes =
2650  std::min<size_t>(sizeof(uint64_t), ASan.LongSize / 8);
2651 
2652  const bool IsLittleEndian = F.getParent()->getDataLayout().isLittleEndian();
2653 
2654  // Poison given range in shadow using larges store size with out leading and
2655  // trailing zeros in ShadowMask. Zeros never change, so they need neither
2656  // poisoning nor up-poisoning. Still we don't mind if some of them get into a
2657  // middle of a store.
2658  for (size_t i = Begin; i < End;) {
2659  if (!ShadowMask[i]) {
2660  assert(!ShadowBytes[i]);
2661  ++i;
2662  continue;
2663  }
2664 
2665  size_t StoreSizeInBytes = LargestStoreSizeInBytes;
2666  // Fit store size into the range.
2667  while (StoreSizeInBytes > End - i)
2668  StoreSizeInBytes /= 2;
2669 
2670  // Minimize store size by trimming trailing zeros.
2671  for (size_t j = StoreSizeInBytes - 1; j && !ShadowMask[i + j]; --j) {
2672  while (j <= StoreSizeInBytes / 2)
2673  StoreSizeInBytes /= 2;
2674  }
2675 
2676  uint64_t Val = 0;
2677  for (size_t j = 0; j < StoreSizeInBytes; j++) {
2678  if (IsLittleEndian)
2679  Val |= (uint64_t)ShadowBytes[i + j] << (8 * j);
2680  else
2681  Val = (Val << 8) | ShadowBytes[i + j];
2682  }
2683 
2684  Value *Ptr = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
2685  Value *Poison = IRB.getIntN(StoreSizeInBytes * 8, Val);
2686  IRB.CreateAlignedStore(
2687  Poison, IRB.CreateIntToPtr(Ptr, Poison->getType()->getPointerTo()), 1);
2688 
2689  i += StoreSizeInBytes;
2690  }
2691 }
2692 
2693 void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2694  ArrayRef<uint8_t> ShadowBytes,
2695  IRBuilder<> &IRB, Value *ShadowBase) {
2696  copyToShadow(ShadowMask, ShadowBytes, 0, ShadowMask.size(), IRB, ShadowBase);
2697 }
2698 
2699 void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2700  ArrayRef<uint8_t> ShadowBytes,
2701  size_t Begin, size_t End,
2702  IRBuilder<> &IRB, Value *ShadowBase) {
2703  assert(ShadowMask.size() == ShadowBytes.size());
2704  size_t Done = Begin;
2705  for (size_t i = Begin, j = Begin + 1; i < End; i = j++) {
2706  if (!ShadowMask[i]) {
2707  assert(!ShadowBytes[i]);
2708  continue;
2709  }
2710  uint8_t Val = ShadowBytes[i];
2711  if (!AsanSetShadowFunc[Val])
2712  continue;
2713 
2714  // Skip same values.
2715  for (; j < End && ShadowMask[j] && Val == ShadowBytes[j]; ++j) {
2716  }
2717 
2718  if (j - i >= ClMaxInlinePoisoningSize) {
2719  copyToShadowInline(ShadowMask, ShadowBytes, Done, i, IRB, ShadowBase);
2720  IRB.CreateCall(AsanSetShadowFunc[Val],
2721  {IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i)),
2722  ConstantInt::get(IntptrTy, j - i)});
2723  Done = j;
2724  }
2725  }
2726 
2727  copyToShadowInline(ShadowMask, ShadowBytes, Done, End, IRB, ShadowBase);
2728 }
2729 
2730 // Fake stack allocator (asan_fake_stack.h) has 11 size classes
2731 // for every power of 2 from kMinStackMallocSize to kMaxAsanStackMallocSizeClass
2732 static int StackMallocSizeClass(uint64_t LocalStackSize) {
2733  assert(LocalStackSize <= kMaxStackMallocSize);
2734  uint64_t MaxSize = kMinStackMallocSize;
2735  for (int i = 0;; i++, MaxSize *= 2)
2736  if (LocalStackSize <= MaxSize) return i;
2737  llvm_unreachable("impossible LocalStackSize");
2738 }
2739 
2740 void FunctionStackPoisoner::copyArgsPassedByValToAllocas() {
2741  Instruction *CopyInsertPoint = &F.front().front();
2742  if (CopyInsertPoint == ASan.LocalDynamicShadow) {
2743  // Insert after the dynamic shadow location is determined
2744  CopyInsertPoint = CopyInsertPoint->getNextNode();
2745  assert(CopyInsertPoint);
2746  }
2747  IRBuilder<> IRB(CopyInsertPoint);
2748  const DataLayout &DL = F.getParent()->getDataLayout();
2749  for (Argument &Arg : F.args()) {
2750  if (Arg.hasByValAttr()) {
2752  unsigned Align = Arg.getParamAlignment();
2753  if (Align == 0) Align = DL.getABITypeAlignment(Ty);
2754 
2755  AllocaInst *AI = IRB.CreateAlloca(
2756  Ty, nullptr,
2757  (Arg.hasName() ? Arg.getName() : "Arg" + Twine(Arg.getArgNo())) +
2758  ".byval");
2759  AI->setAlignment(Align);
2760  Arg.replaceAllUsesWith(AI);
2761 
2762  uint64_t AllocSize = DL.getTypeAllocSize(Ty);
2763  IRB.CreateMemCpy(AI, Align, &Arg, Align, AllocSize);
2764  }
2765  }
2766 }
2767 
2768 PHINode *FunctionStackPoisoner::createPHI(IRBuilder<> &IRB, Value *Cond,
2769  Value *ValueIfTrue,
2770  Instruction *ThenTerm,
2771  Value *ValueIfFalse) {
2772  PHINode *PHI = IRB.CreatePHI(IntptrTy, 2);
2773  BasicBlock *CondBlock = cast<Instruction>(Cond)->getParent();
2774  PHI->addIncoming(ValueIfFalse, CondBlock);
2775  BasicBlock *ThenBlock = ThenTerm->getParent();
2776  PHI->addIncoming(ValueIfTrue, ThenBlock);
2777  return PHI;
2778 }
2779 
2780 Value *FunctionStackPoisoner::createAllocaForLayout(
2781  IRBuilder<> &IRB, const ASanStackFrameLayout &L, bool Dynamic) {
2782  AllocaInst *Alloca;
2783  if (Dynamic) {
2784  Alloca = IRB.CreateAlloca(IRB.getInt8Ty(),
2786  "MyAlloca");
2787  } else {
2788  Alloca = IRB.CreateAlloca(ArrayType::get(IRB.getInt8Ty(), L.FrameSize),
2789  nullptr, "MyAlloca");
2790  assert(Alloca->isStaticAlloca());
2791  }
2792  assert((ClRealignStack & (ClRealignStack - 1)) == 0);
2793  size_t FrameAlignment = std::max(L.FrameAlignment, (size_t)ClRealignStack);
2794  Alloca->setAlignment(FrameAlignment);
2795  return IRB.CreatePointerCast(Alloca, IntptrTy);
2796 }
2797 
2798 void FunctionStackPoisoner::createDynamicAllocasInitStorage() {
2799  BasicBlock &FirstBB = *F.begin();
2800  IRBuilder<> IRB(dyn_cast<Instruction>(FirstBB.begin()));
2801  DynamicAllocaLayout = IRB.CreateAlloca(IntptrTy, nullptr);
2802  IRB.CreateStore(Constant::getNullValue(IntptrTy), DynamicAllocaLayout);
2803  DynamicAllocaLayout->setAlignment(32);
2804 }
2805 
2806 void FunctionStackPoisoner::processDynamicAllocas() {
2807  if (!ClInstrumentDynamicAllocas || DynamicAllocaVec.empty()) {
2808  assert(DynamicAllocaPoisonCallVec.empty());
2809  return;
2810  }
2811 
2812  // Insert poison calls for lifetime intrinsics for dynamic allocas.
2813  for (const auto &APC : DynamicAllocaPoisonCallVec) {
2814  assert(APC.InsBefore);
2815  assert(APC.AI);
2816  assert(ASan.isInterestingAlloca(*APC.AI));
2817  assert(!APC.AI->isStaticAlloca());
2818 
2819  IRBuilder<> IRB(APC.InsBefore);
2820  poisonAlloca(APC.AI, APC.Size, IRB, APC.DoPoison);
2821  // Dynamic allocas will be unpoisoned unconditionally below in
2822  // unpoisonDynamicAllocas.
2823  // Flag that we need unpoison static allocas.
2824  }
2825 
2826  // Handle dynamic allocas.
2827  createDynamicAllocasInitStorage();
2828  for (auto &AI : DynamicAllocaVec)
2829  handleDynamicAllocaCall(AI);
2830  unpoisonDynamicAllocas();
2831 }
2832 
2833 void FunctionStackPoisoner::processStaticAllocas() {
2834  if (AllocaVec.empty()) {
2835  assert(StaticAllocaPoisonCallVec.empty());
2836  return;
2837  }
2838 
2839  int StackMallocIdx = -1;
2840  DebugLoc EntryDebugLocation;
2841  if (auto SP = F.getSubprogram())
2842  EntryDebugLocation = DebugLoc::get(SP->getScopeLine(), 0, SP);
2843 
2844  Instruction *InsBefore = AllocaVec[0];
2845  IRBuilder<> IRB(InsBefore);
2846  IRB.SetCurrentDebugLocation(EntryDebugLocation);
2847 
2848  // Make sure non-instrumented allocas stay in the entry block. Otherwise,
2849  // debug info is broken, because only entry-block allocas are treated as
2850  // regular stack slots.
2851  auto InsBeforeB = InsBefore->getParent();
2852  assert(InsBeforeB == &F.getEntryBlock());
2853  for (auto *AI : StaticAllocasToMoveUp)
2854  if (AI->getParent() == InsBeforeB)
2855  AI->moveBefore(InsBefore);
2856 
2857  // If we have a call to llvm.localescape, keep it in the entry block.
2858  if (LocalEscapeCall) LocalEscapeCall->moveBefore(InsBefore);
2859 
2861  SVD.reserve(AllocaVec.size());
2862  for (AllocaInst *AI : AllocaVec) {
2864  ASan.getAllocaSizeInBytes(*AI),
2865  0,
2866  AI->getAlignment(),
2867  AI,
2868  0,
2869  0};
2870  SVD.push_back(D);
2871  }
2872 
2873  // Minimal header size (left redzone) is 4 pointers,
2874  // i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms.
2875  size_t Granularity = 1ULL << Mapping.Scale;
2876  size_t MinHeaderSize = std::max((size_t)ASan.LongSize / 2, Granularity);
2877  const ASanStackFrameLayout &L =
2878  ComputeASanStackFrameLayout(SVD, Granularity, MinHeaderSize);
2879 
2880  // Build AllocaToSVDMap for ASanStackVariableDescription lookup.
2882  for (auto &Desc : SVD)
2883  AllocaToSVDMap[Desc.AI] = &Desc;
2884 
2885  // Update SVD with information from lifetime intrinsics.
2886  for (const auto &APC : StaticAllocaPoisonCallVec) {
2887  assert(APC.InsBefore);
2888  assert(APC.AI);
2889  assert(ASan.isInterestingAlloca(*APC.AI));
2890  assert(APC.AI->isStaticAlloca());
2891 
2892  ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
2893  Desc.LifetimeSize = Desc.Size;
2894  if (const DILocation *FnLoc = EntryDebugLocation.get()) {
2895  if (const DILocation *LifetimeLoc = APC.InsBefore->getDebugLoc().get()) {
2896  if (LifetimeLoc->getFile() == FnLoc->getFile())
2897  if (unsigned Line = LifetimeLoc->getLine())
2898  Desc.Line = std::min(Desc.Line ? Desc.Line : Line, Line);
2899  }
2900  }
2901  }
2902 
2903  auto DescriptionString = ComputeASanStackFrameDescription(SVD);
2904  LLVM_DEBUG(dbgs() << DescriptionString << " --- " << L.FrameSize << "\n");
2905  uint64_t LocalStackSize = L.FrameSize;
2906  bool DoStackMalloc = ClUseAfterReturn && !ASan.CompileKernel &&
2907  LocalStackSize <= kMaxStackMallocSize;
2908  bool DoDynamicAlloca = ClDynamicAllocaStack;
2909  // Don't do dynamic alloca or stack malloc if:
2910  // 1) There is inline asm: too often it makes assumptions on which registers
2911  // are available.
2912  // 2) There is a returns_twice call (typically setjmp), which is
2913  // optimization-hostile, and doesn't play well with introduced indirect
2914  // register-relative calculation of local variable addresses.
2915  DoDynamicAlloca &= !HasNonEmptyInlineAsm && !HasReturnsTwiceCall;
2916  DoStackMalloc &= !HasNonEmptyInlineAsm && !HasReturnsTwiceCall;
2917 
2918  Value *StaticAlloca =
2919  DoDynamicAlloca ? nullptr : createAllocaForLayout(IRB, L, false);
2920 
2921  Value *FakeStack;
2922  Value *LocalStackBase;
2923  Value *LocalStackBaseAlloca;
2924  bool Deref;
2925 
2926  if (DoStackMalloc) {
2927  LocalStackBaseAlloca =
2928  IRB.CreateAlloca(IntptrTy, nullptr, "asan_local_stack_base");
2929  // void *FakeStack = __asan_option_detect_stack_use_after_return
2930  // ? __asan_stack_malloc_N(LocalStackSize)
2931  // : nullptr;
2932  // void *LocalStackBase = (FakeStack) ? FakeStack : alloca(LocalStackSize);
2933  Constant *OptionDetectUseAfterReturn = F.getParent()->getOrInsertGlobal(
2934  kAsanOptionDetectUseAfterReturn, IRB.getInt32Ty());
2935  Value *UseAfterReturnIsEnabled =
2936  IRB.CreateICmpNE(IRB.CreateLoad(OptionDetectUseAfterReturn),
2938  Instruction *Term =
2939  SplitBlockAndInsertIfThen(UseAfterReturnIsEnabled, InsBefore, false);
2940  IRBuilder<> IRBIf(Term);
2941  IRBIf.SetCurrentDebugLocation(EntryDebugLocation);
2942  StackMallocIdx = StackMallocSizeClass(LocalStackSize);
2943  assert(StackMallocIdx <= kMaxAsanStackMallocSizeClass);
2944  Value *FakeStackValue =
2945  IRBIf.CreateCall(AsanStackMallocFunc[StackMallocIdx],
2946  ConstantInt::get(IntptrTy, LocalStackSize));
2947  IRB.SetInsertPoint(InsBefore);
2948  IRB.SetCurrentDebugLocation(EntryDebugLocation);
2949  FakeStack = createPHI(IRB, UseAfterReturnIsEnabled, FakeStackValue, Term,
2950  ConstantInt::get(IntptrTy, 0));
2951 
2952  Value *NoFakeStack =
2953  IRB.CreateICmpEQ(FakeStack, Constant::getNullValue(IntptrTy));
2954  Term = SplitBlockAndInsertIfThen(NoFakeStack, InsBefore, false);
2955  IRBIf.SetInsertPoint(Term);
2956  IRBIf.SetCurrentDebugLocation(EntryDebugLocation);
2957  Value *AllocaValue =
2958  DoDynamicAlloca ? createAllocaForLayout(IRBIf, L, true) : StaticAlloca;
2959 
2960  IRB.SetInsertPoint(InsBefore);
2961  IRB.SetCurrentDebugLocation(EntryDebugLocation);
2962  LocalStackBase = createPHI(IRB, NoFakeStack, AllocaValue, Term, FakeStack);
2963  IRB.SetCurrentDebugLocation(EntryDebugLocation);
2964  IRB.CreateStore(LocalStackBase, LocalStackBaseAlloca);
2965  Deref = true;
2966  } else {
2967  // void *FakeStack = nullptr;
2968  // void *LocalStackBase = alloca(LocalStackSize);
2969  FakeStack = ConstantInt::get(IntptrTy, 0);
2970  LocalStackBase =
2971  DoDynamicAlloca ? createAllocaForLayout(IRB, L, true) : StaticAlloca;
2972  LocalStackBaseAlloca = LocalStackBase;
2973  Deref = false;
2974  }
2975 
2976  // Replace Alloca instructions with base+offset.
2977  for (const auto &Desc : SVD) {
2978  AllocaInst *AI = Desc.AI;
2979  replaceDbgDeclareForAlloca(AI, LocalStackBaseAlloca, DIB, Deref,
2980  Desc.Offset, DIExpression::NoDeref);
2981  Value *NewAllocaPtr = IRB.CreateIntToPtr(
2982  IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Desc.Offset)),
2983  AI->getType());
2984  AI->replaceAllUsesWith(NewAllocaPtr);
2985  }
2986 
2987  // The left-most redzone has enough space for at least 4 pointers.
2988  // Write the Magic value to redzone[0].
2989  Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
2991  BasePlus0);
2992  // Write the frame description constant to redzone[1].
2993  Value *BasePlus1 = IRB.CreateIntToPtr(
2994  IRB.CreateAdd(LocalStackBase,
2995  ConstantInt::get(IntptrTy, ASan.LongSize / 8)),
2996  IntptrPtrTy);
2997  GlobalVariable *StackDescriptionGlobal =
2998  createPrivateGlobalForString(*F.getParent(), DescriptionString,
2999  /*AllowMerging*/ true);
3000  Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal, IntptrTy);
3001  IRB.CreateStore(Description, BasePlus1);
3002  // Write the PC to redzone[2].
3003  Value *BasePlus2 = IRB.CreateIntToPtr(
3004  IRB.CreateAdd(LocalStackBase,
3005  ConstantInt::get(IntptrTy, 2 * ASan.LongSize / 8)),
3006  IntptrPtrTy);
3007  IRB.CreateStore(IRB.CreatePointerCast(&F, IntptrTy), BasePlus2);
3008 
3009  const auto &ShadowAfterScope = GetShadowBytesAfterScope(SVD, L);
3010 
3011  // Poison the stack red zones at the entry.
3012  Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
3013  // As mask we must use most poisoned case: red zones and after scope.
3014  // As bytes we can use either the same or just red zones only.
3015  copyToShadow(ShadowAfterScope, ShadowAfterScope, IRB, ShadowBase);
3016 
3017  if (!StaticAllocaPoisonCallVec.empty()) {
3018  const auto &ShadowInScope = GetShadowBytes(SVD, L);
3019 
3020  // Poison static allocas near lifetime intrinsics.
3021  for (const auto &APC : StaticAllocaPoisonCallVec) {
3022  const ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3023  assert(Desc.Offset % L.Granularity == 0);
3024  size_t Begin = Desc.Offset / L.Granularity;
3025  size_t End = Begin + (APC.Size + L.Granularity - 1) / L.Granularity;
3026 
3027  IRBuilder<> IRB(APC.InsBefore);
3028  copyToShadow(ShadowAfterScope,
3029  APC.DoPoison ? ShadowAfterScope : ShadowInScope, Begin, End,
3030  IRB, ShadowBase);
3031  }
3032  }
3033 
3034  SmallVector<uint8_t, 64> ShadowClean(ShadowAfterScope.size(), 0);
3035  SmallVector<uint8_t, 64> ShadowAfterReturn;
3036 
3037  // (Un)poison the stack before all ret instructions.
3038  for (auto Ret : RetVec) {
3039  IRBuilder<> IRBRet(Ret);
3040  // Mark the current frame as retired.
3042  BasePlus0);
3043  if (DoStackMalloc) {
3044  assert(StackMallocIdx >= 0);
3045  // if FakeStack != 0 // LocalStackBase == FakeStack
3046  // // In use-after-return mode, poison the whole stack frame.
3047  // if StackMallocIdx <= 4
3048  // // For small sizes inline the whole thing:
3049  // memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
3050  // **SavedFlagPtr(FakeStack) = 0
3051  // else
3052  // __asan_stack_free_N(FakeStack, LocalStackSize)
3053  // else
3054  // <This is not a fake stack; unpoison the redzones>
3055  Value *Cmp =
3056  IRBRet.CreateICmpNE(FakeStack, Constant::getNullValue(IntptrTy));
3057  TerminatorInst *ThenTerm, *ElseTerm;
3058  SplitBlockAndInsertIfThenElse(Cmp, Ret, &ThenTerm, &ElseTerm);
3059 
3060  IRBuilder<> IRBPoison(ThenTerm);
3061  if (StackMallocIdx <= 4) {
3062  int ClassSize = kMinStackMallocSize << StackMallocIdx;
3063  ShadowAfterReturn.resize(ClassSize / L.Granularity,
3065  copyToShadow(ShadowAfterReturn, ShadowAfterReturn, IRBPoison,
3066  ShadowBase);
3067  Value *SavedFlagPtrPtr = IRBPoison.CreateAdd(
3068  FakeStack,
3069  ConstantInt::get(IntptrTy, ClassSize - ASan.LongSize / 8));
3070  Value *SavedFlagPtr = IRBPoison.CreateLoad(
3071  IRBPoison.CreateIntToPtr(SavedFlagPtrPtr, IntptrPtrTy));
3072  IRBPoison.CreateStore(
3073  Constant::getNullValue(IRBPoison.getInt8Ty()),
3074  IRBPoison.CreateIntToPtr(SavedFlagPtr, IRBPoison.getInt8PtrTy()));
3075  } else {
3076  // For larger frames call __asan_stack_free_*.
3077  IRBPoison.CreateCall(
3078  AsanStackFreeFunc[StackMallocIdx],
3079  {FakeStack, ConstantInt::get(IntptrTy, LocalStackSize)});
3080  }
3081 
3082  IRBuilder<> IRBElse(ElseTerm);
3083  copyToShadow(ShadowAfterScope, ShadowClean, IRBElse, ShadowBase);
3084  } else {
3085  copyToShadow(ShadowAfterScope, ShadowClean, IRBRet, ShadowBase);
3086  }
3087  }
3088 
3089  // We are done. Remove the old unused alloca instructions.
3090  for (auto AI : AllocaVec) AI->eraseFromParent();
3091 }
3092 
3093 void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
3094  IRBuilder<> &IRB, bool DoPoison) {
3095  // For now just insert the call to ASan runtime.
3096  Value *AddrArg = IRB.CreatePointerCast(V, IntptrTy);
3097  Value *SizeArg = ConstantInt::get(IntptrTy, Size);
3098  IRB.CreateCall(
3099  DoPoison ? AsanPoisonStackMemoryFunc : AsanUnpoisonStackMemoryFunc,
3100  {AddrArg, SizeArg});
3101 }
3102 
3103 // Handling llvm.lifetime intrinsics for a given %alloca:
3104 // (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
3105 // (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
3106 // invalid accesses) and unpoison it for llvm.lifetime.start (the memory
3107 // could be poisoned by previous llvm.lifetime.end instruction, as the
3108 // variable may go in and out of scope several times, e.g. in loops).
3109 // (3) if we poisoned at least one %alloca in a function,
3110 // unpoison the whole stack frame at function exit.
3111 
3112 AllocaInst *FunctionStackPoisoner::findAllocaForValue(Value *V) {
3113  if (AllocaInst *AI = dyn_cast<AllocaInst>(V))
3114  // We're interested only in allocas we can handle.
3115  return ASan.isInterestingAlloca(*AI) ? AI : nullptr;
3116  // See if we've already calculated (or started to calculate) alloca for a
3117  // given value.
3118  AllocaForValueMapTy::iterator I = AllocaForValue.find(V);
3119  if (I != AllocaForValue.end()) return I->second;
3120  // Store 0 while we're calculating alloca for value V to avoid
3121  // infinite recursion if the value references itself.
3122  AllocaForValue[V] = nullptr;
3123  AllocaInst *Res = nullptr;
3124  if (CastInst *CI = dyn_cast<CastInst>(V))
3125  Res = findAllocaForValue(CI->getOperand(0));
3126  else if (PHINode *PN = dyn_cast<PHINode>(V)) {
3127  for (Value *IncValue : PN->incoming_values()) {
3128  // Allow self-referencing phi-nodes.
3129  if (IncValue == PN) continue;
3130  AllocaInst *IncValueAI = findAllocaForValue(IncValue);
3131  // AI for incoming values should exist and should all be equal.
3132  if (IncValueAI == nullptr || (Res != nullptr && IncValueAI != Res))
3133  return nullptr;
3134  Res = IncValueAI;
3135  }
3136  } else if (GetElementPtrInst *EP = dyn_cast<GetElementPtrInst>(V)) {
3137  Res = findAllocaForValue(EP->getPointerOperand());
3138  } else {
3139  LLVM_DEBUG(dbgs() << "Alloca search canceled on unknown instruction: " << *V
3140  << "\n");
3141  }
3142  if (Res) AllocaForValue[V] = Res;
3143  return Res;
3144 }
3145 
3146 void FunctionStackPoisoner::handleDynamicAllocaCall(AllocaInst *AI) {
3147  IRBuilder<> IRB(AI);
3148 
3149  const unsigned Align = std::max(kAllocaRzSize, AI->getAlignment());
3150  const uint64_t AllocaRedzoneMask = kAllocaRzSize - 1;
3151 
3152  Value *Zero = Constant::getNullValue(IntptrTy);
3153  Value *AllocaRzSize = ConstantInt::get(IntptrTy, kAllocaRzSize);
3154  Value *AllocaRzMask = ConstantInt::get(IntptrTy, AllocaRedzoneMask);
3155 
3156  // Since we need to extend alloca with additional memory to locate
3157  // redzones, and OldSize is number of allocated blocks with
3158  // ElementSize size, get allocated memory size in bytes by
3159  // OldSize * ElementSize.
3160  const unsigned ElementSize =
3162  Value *OldSize =
3163  IRB.CreateMul(IRB.CreateIntCast(AI->getArraySize(), IntptrTy, false),
3164  ConstantInt::get(IntptrTy, ElementSize));
3165 
3166  // PartialSize = OldSize % 32
3167  Value *PartialSize = IRB.CreateAnd(OldSize, AllocaRzMask);
3168 
3169  // Misalign = kAllocaRzSize - PartialSize;
3170  Value *Misalign = IRB.CreateSub(AllocaRzSize, PartialSize);
3171 
3172  // PartialPadding = Misalign != kAllocaRzSize ? Misalign : 0;
3173  Value *Cond = IRB.CreateICmpNE(Misalign, AllocaRzSize);
3174  Value *PartialPadding = IRB.CreateSelect(Cond, Misalign, Zero);
3175 
3176  // AdditionalChunkSize = Align + PartialPadding + kAllocaRzSize
3177  // Align is added to locate left redzone, PartialPadding for possible
3178  // partial redzone and kAllocaRzSize for right redzone respectively.
3179  Value *AdditionalChunkSize = IRB.CreateAdd(
3180  ConstantInt::get(IntptrTy, Align + kAllocaRzSize), PartialPadding);
3181 
3182  Value *NewSize = IRB.CreateAdd(OldSize, AdditionalChunkSize);
3183 
3184  // Insert new alloca with new NewSize and Align params.
3185  AllocaInst *NewAlloca = IRB.CreateAlloca(IRB.getInt8Ty(), NewSize);
3186  NewAlloca->setAlignment(Align);
3187 
3188  // NewAddress = Address + Align
3189  Value *NewAddress = IRB.CreateAdd(IRB.CreatePtrToInt(NewAlloca, IntptrTy),
3190  ConstantInt::get(IntptrTy, Align));
3191 
3192  // Insert __asan_alloca_poison call for new created alloca.
3193  IRB.CreateCall(AsanAllocaPoisonFunc, {NewAddress, OldSize});
3194 
3195  // Store the last alloca's address to DynamicAllocaLayout. We'll need this
3196  // for unpoisoning stuff.
3197  IRB.CreateStore(IRB.CreatePtrToInt(NewAlloca, IntptrTy), DynamicAllocaLayout);
3198 
3199  Value *NewAddressPtr = IRB.CreateIntToPtr(NewAddress, AI->getType());
3200 
3201  // Replace all uses of AddessReturnedByAlloca with NewAddressPtr.
3202  AI->replaceAllUsesWith(NewAddressPtr);
3203 
3204  // We are done. Erase old alloca from parent.
3205  AI->eraseFromParent();
3206 }
3207 
3208 // isSafeAccess returns true if Addr is always inbounds with respect to its
3209 // base object. For example, it is a field access or an array access with
3210 // constant inbounds index.
3211 bool AddressSanitizer::isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis,
3212  Value *Addr, uint64_t TypeSize) const {
3213  SizeOffsetType SizeOffset = ObjSizeVis.compute(Addr);
3214  if (!ObjSizeVis.bothKnown(SizeOffset)) return false;
3215  uint64_t Size = SizeOffset.first.getZExtValue();
3216  int64_t Offset = SizeOffset.second.getSExtValue();
3217  // Three checks are required to ensure safety:
3218  // . Offset >= 0 (since the offset is given from the base ptr)
3219  // . Size >= Offset (unsigned)
3220  // . Size - Offset >= NeededSize (unsigned)
3221  return Offset >= 0 && Size >= uint64_t(Offset) &&
3222  Size - uint64_t(Offset) >= TypeSize / 8;
3223 }
void setVisibility(VisibilityTypes V)
Definition: GlobalValue.h:238
Pass interface - Implemented by all &#39;passes&#39;.
Definition: Pass.h:81
static const uint64_t kMyriadCacheBitMask32
static cl::opt< std::string > ClDebugFunc("asan-debug-func", cl::Hidden, cl::desc("Debug func"))
static bool isValueValidForType(Type *Ty, uint64_t V)
This static method returns true if the type Ty is big enough to represent the value V...
Definition: Constants.cpp:1244
uint64_t CallInst * C
void appendToCompilerUsed(Module &M, ArrayRef< GlobalValue *> Values)
Adds global values to the llvm.compiler.used list.
Return a value (possibly void), from a function.
StringRef getSection() const
Get the custom section of this global if it has one.
Definition: GlobalObject.h:90
SymbolTableList< Instruction >::iterator eraseFromParent()
This method unlinks &#39;this&#39; from the containing basic block and deletes it.
Definition: Instruction.cpp:68
static const char *const kAsanSetShadowPrefix
unsigned getAlignment() const
Definition: GlobalObject.h:59
static const uint64_t kIOSShadowOffset32
static cl::opt< bool > ClStack("asan-stack", cl::desc("Handle stack memory"), cl::Hidden, cl::init(true))
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:111
constexpr char Align[]
Key for Kernel::Arg::Metadata::mAlign.
uint64_t getTypeStoreSizeInBits(Type *Ty) const
Returns the maximum number of bits that may be overwritten by storing the specified type; always a mu...
Definition: DataLayout.h:419
const std::string & getTargetTriple() const
Get the target triple which is a string describing the target host.
Definition: Module.h:238
ThreadLocalMode getThreadLocalMode() const
Definition: GlobalValue.h:254
void ReplaceInstWithInst(BasicBlock::InstListType &BIL, BasicBlock::iterator &BI, Instruction *I)
Replace the instruction specified by BI with the instruction specified by I.
Function * declareSanitizerInitFunction(Module &M, StringRef InitName, ArrayRef< Type *> InitArgTypes)
static Constant * getString(LLVMContext &Context, StringRef Initializer, bool AddNull=true)
This method constructs a CDS and initializes it with a text string.
Definition: Constants.cpp:2515
void appendToGlobalDtors(Module &M, Function *F, int Priority, Constant *Data=nullptr)
Same as appendToGlobalCtors(), but for global dtors.
Definition: ModuleUtils.cpp:88
bool hasLocalLinkage() const
Definition: GlobalValue.h:435
static const uint64_t kFreeBSD_ShadowOffset64
static cl::opt< bool > ClInitializers("asan-initialization-order", cl::desc("Handle C++ initializer order"), cl::Hidden, cl::init(true))
DILocation * get() const
Get the underlying DILocation.
Definition: DebugLoc.cpp:22
void addIncoming(Value *V, BasicBlock *BB)
Add an incoming value to the end of the PHI list.
static PassRegistry * getPassRegistry()
getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...
bool isMIPS64() const
Tests whether the target is MIPS 64-bit (little and big endian).
Definition: Triple.h:669
static bool GlobalWasGeneratedByCompiler(GlobalVariable *G)
Check if G has been created by a trusted compiler pass.
GCNRegPressure max(const GCNRegPressure &P1, const GCNRegPressure &P2)
void SplitBlockAndInsertIfThenElse(Value *Cond, Instruction *SplitBefore, TerminatorInst **ThenTerm, TerminatorInst **ElseTerm, MDNode *BranchWeights=nullptr)
SplitBlockAndInsertIfThenElse is similar to SplitBlockAndInsertIfThen, but also creates the ElseBlock...
This class represents an incoming formal argument to a Function.
Definition: Argument.h:30
AllocaInst * CreateAlloca(Type *Ty, unsigned AddrSpace, Value *ArraySize=nullptr, const Twine &Name="")
Definition: IRBuilder.h:1292
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))
bool replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress, DIBuilder &Builder, bool DerefBefore, int Offset, bool DerefAfter)
Replaces llvm.dbg.declare instruction when the alloca it describes is replaced with a new value...
Definition: Local.cpp:1555
Function * checkSanitizerInterfaceFunction(Constant *FuncOrBitcast)
Value * CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1740
NodeTy * getNextNode()
Get the next node, or nullptr for the list tail.
Definition: ilist_node.h:289
bool hasPrivateLinkage() const
Definition: GlobalValue.h:434
const Constant * getInitializer() const
getInitializer - Return the initializer for this global variable.
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool contains(StringRef Other) const
Return true if the given string is a substring of *this, and false otherwise.
Definition: StringRef.h:448
static size_t RedzoneSizeForScale(int MappingScale)
static ShadowMapping getShadowMapping(Triple &TargetTriple, int LongSize, bool IsKasan)
Constant * getOrInsertFunction(StringRef Name, FunctionType *T, AttributeList AttributeList)
Look up the specified function in the module symbol table.
Definition: Module.cpp:142
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:63
static Constant * getGetElementPtr(Type *Ty, Constant *C, ArrayRef< Constant *> IdxList, bool InBounds=false, Optional< unsigned > InRangeIndex=None, Type *OnlyIfReducedTy=nullptr)
Getelementptr form.
Definition: Constants.h:1143
bool isSized(SmallPtrSetImpl< Type *> *Visited=nullptr) const
Return true if it makes sense to take the size of this type.
Definition: Type.h:265
BasicBlock * getSuccessor(unsigned idx) const
Return the specified successor.
void setAlignment(unsigned Align)
an instruction that atomically checks whether a specified value is in a memory location, and, if it is, stores a new value there.
Definition: Instructions.h:518
Available for inspection, not emission.
Definition: GlobalValue.h:50
static const char *const kAsanUnregisterElfGlobalsName
static const uintptr_t kCurrentStackFrameMagic
This class represents a function call, abstracting a target machine&#39;s calling convention.
This file contains the declarations for metadata subclasses.
static cl::opt< bool > ClUseAfterReturn("asan-use-after-return", cl::desc("Check stack-use-after-return"), cl::Hidden, cl::init(true))
static PointerType * get(Type *ElementType, unsigned AddressSpace)
This constructs a pointer to an object of the specified type in a numbered address space...
Definition: Type.cpp:617
static bool isInterestingPointerComparisonOrSubtraction(Instruction *I)
static const char *const kODRGenPrefix
bool isSwiftError() const
Return true if this alloca is used as a swifterror argument to a call.
Definition: Instructions.h:136
This file contains the declaration of the Comdat class, which represents a single COMDAT in LLVM...
static cl::opt< bool > ClWithIfunc("asan-with-ifunc", cl::desc("Access dynamic shadow through an ifunc global on " "platforms that support this"), cl::Hidden, cl::init(true))
bool isWatchOS() const
Is this an Apple watchOS triple.
Definition: Triple.h:461
Like Internal, but omit from symbol table.
Definition: GlobalValue.h:57
bool RoundToAlign
Whether to round the result up to the alignment of allocas, byval arguments, and global variables...
Externally visible function.
Definition: GlobalValue.h:49
static cl::opt< bool > ClForceDynamicShadow("asan-force-dynamic-shadow", cl::desc("Load shadow address into a local variable for each function"), cl::Hidden, cl::init(false))
bool hasFnAttribute(Attribute::AttrKind Kind) const
Return true if the function has the attribute.
Definition: Function.h:307
static cl::opt< int > ClDebug("asan-debug", cl::desc("debug"), cl::Hidden, cl::init(0))
static cl::opt< bool > ClRecover("asan-recover", cl::desc("Enable recovery mode (continue-after-error)."), cl::Hidden, cl::init(false))
GlobalVariable * getGlobalVariable(StringRef Name) const
Look up the specified global variable in the module symbol table.
Definition: Module.h:380
INITIALIZE_PASS_BEGIN(AddressSanitizer, "asan", "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false, false) INITIALIZE_PASS_END(AddressSanitizer
unsigned getPointerSizeInBits(unsigned AS=0) const
Layout pointer size, in bits FIXME: The defaults need to be removed once all of the backends/clients ...
Definition: DataLayout.h:360
STATISTIC(NumFunctions, "Total number of functions")
SmallString< 64 > ComputeASanStackFrameDescription(const SmallVectorImpl< ASanStackVariableDescription > &Vars)
A debug info location.
Definition: DebugLoc.h:34
Metadata node.
Definition: Metadata.h:862
StringRef getName() const
Get a short "name" for the module.
Definition: Module.h:225
static cl::opt< bool > ClUseAfterScope("asan-use-after-scope", cl::desc("Check stack-use-after-scope"), cl::Hidden, cl::init(false))
F(f)
static CallInst * Create(Value *Func, ArrayRef< Value *> Args, ArrayRef< OperandBundleDef > Bundles=None, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
const MDOperand & getOperand(unsigned I) const
Definition: Metadata.h:1067
unsigned getPointerAddressSpace() const
Get the address space of this pointer or pointer vector type.
Definition: DerivedTypes.h:503
bool isOSFuchsia() const
Definition: Triple.h:490
An instruction for reading from memory.
Definition: Instructions.h:168
an instruction that atomically reads a memory location, combines it with another value, and then stores the result back.
Definition: Instructions.h:681
This defines the Use class.
void reserve(size_type N)
Definition: SmallVector.h:376
void setAlignment(unsigned Align)
Definition: Globals.cpp:111
static GlobalVariable * createPrivateGlobalForString(Module &M, StringRef Str, bool AllowMerging)
static cl::opt< unsigned long long > ClMappingOffset("asan-mapping-offset", cl::desc("offset of asan shadow mapping [EXPERIMENTAL]"), cl::Hidden, cl::init(0))
Tentative definitions.
Definition: GlobalValue.h:59
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:128
static Constant * get(ArrayType *T, ArrayRef< Constant *> V)
Definition: Constants.cpp:960
static const uint64_t kMyriadDDRTag
bool isAllocaPromotable(const AllocaInst *AI)
Return true if this alloca is legal for promotion.
static Constant * getNullValue(Type *Ty)
Constructor to create a &#39;0&#39; constant of arbitrary type.
Definition: Constants.cpp:268
StoreInst * CreateAlignedStore(Value *Val, Value *Ptr, unsigned Align, bool isVolatile=false)
Definition: IRBuilder.h:1346
iterator begin()
Instruction iterator methods.
Definition: BasicBlock.h:264
static void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I, Instruction *InsertBefore, Value *Addr, unsigned Alignment, unsigned Granularity, uint32_t TypeSize, bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp)
static ReturnInst * Create(LLVMContext &C, Value *retVal=nullptr, Instruction *InsertBefore=nullptr)
IntegerType * getInt32Ty()
Fetch the type representing a 32-bit integer.
Definition: IRBuilder.h:347
static const uint64_t kDefaultShadowScale
static const char *const kAsanShadowMemoryDynamicAddress
static const int kAsanStackUseAfterReturnMagic
AnalysisUsage & addRequired()
#define INITIALIZE_PASS_DEPENDENCY(depName)
Definition: PassSupport.h:51
A tuple of MDNodes.
Definition: Metadata.h:1323
bool doesNotReturn() const
Determine if the call cannot return.
Definition: CallSite.h:497
Type * getPointerElementType() const
Definition: Type.h:376
const DataLayout & getDataLayout() const
Get the data layout for the module&#39;s target platform.
Definition: Module.cpp:361
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
unsigned getAlignment() const
Return the alignment of the memory that is being allocated by the instruction.
Definition: Instructions.h:113
IntegerType * getInt64Ty()
Fetch the type representing a 64-bit integer.
Definition: IRBuilder.h:352
This is the base class for all instructions that perform data casts.
Definition: InstrTypes.h:592
PointerType * getType() const
Overload to return most specific pointer type.
Definition: Instructions.h:97
Class to represent struct types.
Definition: DerivedTypes.h:201
LLVMContext & getContext() const
Get the global data context.
Definition: Module.h:242
static const uint64_t kSmallX86_64ShadowOffsetBase
static const uint64_t kLinuxKasan_ShadowOffset64
A Use represents the edge between a Value definition and its users.
Definition: Use.h:56
PointerType * getPointerTo(unsigned AddrSpace=0) const
Return a pointer to the current type.
Definition: Type.cpp:639
bool isConstant() const
If the value is a global constant, its value is immutable throughout the runtime execution of the pro...
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
Definition: IRBuilder.h:731
This file contains the simple types necessary to represent the attributes associated with functions a...
InstrTy * getInstruction() const
Definition: CallSite.h:92
static const char *const kAsanAllocasUnpoison
Value * CreateAdd(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:962
void setName(const Twine &Name)
Change the name of the value.
Definition: Value.cpp:295
static const char *const kAsanModuleCtorName
static const uint64_t kIOSSimShadowOffset64
static const uint64_t kMyriadMemoryOffset32
static StructType * get(LLVMContext &Context, ArrayRef< Type *> Elements, bool isPacked=false)
This static method is the primary way to create a literal StructType.
Definition: Type.cpp:336
Type * getVoidTy()
Fetch the type representing void.
Definition: IRBuilder.h:380
StoreInst * CreateStore(Value *Val, Value *Ptr, bool isVolatile=false)
Definition: IRBuilder.h:1321
Value * CreateIntToPtr(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1624
bool isOne() const
This is just a convenience method to make client code smaller for a common case.
Definition: Constants.h:201
static const uint64_t kSmallX86_64ShadowOffsetAlignMask
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool startswith(StringRef Prefix) const
Check if this string starts with the given Prefix.
Definition: StringRef.h:267
static const char *const kAsanPoisonStackMemoryName
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:245
SmallVector< uint8_t, 64 > GetShadowBytesAfterScope(const SmallVectorImpl< ASanStackVariableDescription > &Vars, const ASanStackFrameLayout &Layout)
std::string itostr(int64_t X)
Definition: StringExtras.h:238
ConstantDataSequential - A vector or array constant whose element type is a simple 1/2/4/8-byte integ...
Definition: Constants.h:570
static const char *const kSanCovGenPrefix
bool empty() const
Definition: Module.h:593
bool isSwiftError() const
Return true if this value is a swifterror value.
Definition: Value.cpp:735
ArchType getArch() const
getArch - Get the parsed architecture type of this triple.
Definition: Triple.h:285
Class to represent array types.
Definition: DerivedTypes.h:369
bool isUsedWithInAlloca() const
Return true if this alloca is used as an inalloca argument to a call.
Definition: Instructions.h:125
static const int kMaxAsanStackMallocSizeClass
static const uint64_t kIOSSimShadowOffset32
static cl::opt< bool > ClOptSameTemp("asan-opt-same-temp", cl::desc("Instrument the same temp just once"), cl::Hidden, cl::init(true))
static cl::opt< bool > ClEnableKasan("asan-kernel", cl::desc("Enable KernelAddressSanitizer instrumentation"), cl::Hidden, cl::init(false))
static const uint64_t kAsanCtorAndDtorPriority
void setComdat(Comdat *C)
Definition: GlobalObject.h:103
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:133
NamedMDNode * getNamedMetadata(const Twine &Name) const
Return the first NamedMDNode in the module with the specified name.
Definition: Module.cpp:242
static cl::opt< bool > ClOpt("asan-opt", cl::desc("Optimize instrumentation"), cl::Hidden, cl::init(true))
MDNode * getMetadata(unsigned KindID) const
Get the metadata of given kind attached to this Instruction.
Definition: Instruction.h:200
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
const APInt & getValue() const
Return the constant as an APInt value reference.
Definition: Constants.h:138
bool isLittleEndian() const
Layout endianness...
Definition: DataLayout.h:221
static const uint64_t kWindowsShadowOffset64
Value * CreateSub(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:979
bool isiOS() const
Is this an iOS triple.
Definition: Triple.h:451
An instruction for storing to memory.
Definition: Instructions.h:310
void SetCurrentDebugLocation(DebugLoc L)
Set location information used by debugging information.
Definition: IRBuilder.h:151
bool isMinusOne() const
This function will return true iff every bit in this constant is set to true.
Definition: Constants.h:209
static const uint64_t kMyriadTagShift
LinkageTypes getLinkage() const
Definition: GlobalValue.h:450
void replaceAllUsesWith(Value *V)
Change all uses of this to point to a new Value.
Definition: Value.cpp:439
bool isOSNetBSD() const
Definition: Triple.h:478
Debug location.
void takeName(Value *V)
Transfer the name from V to this value.
Definition: Value.cpp:301
iterator begin()
Definition: Function.h:642
static cl::opt< bool > ClAlwaysSlowPath("asan-always-slow-path", cl::desc("use instrumentation with slow path for all accesses"), cl::Hidden, cl::init(false))
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree...
Definition: Dominators.h:142
iterator_range< op_iterator > operands()
Definition: Metadata.h:1415
Function * getDeclaration(Module *M, ID id, ArrayRef< Type *> Tys=None)
Create or insert an LLVM Function declaration for an intrinsic, and return it.
Definition: Function.cpp:1007
void SetInsertPoint(BasicBlock *TheBB)
This specifies that created instructions should be appended to the end of the specified block...
Definition: IRBuilder.h:127
static const uint64_t kDefaultShadowOffset32
Value * getOperand(unsigned i) const
Definition: User.h:170
ConstantInt * getIntN(unsigned N, uint64_t C)
Get a constant N-bit value, zero extended or truncated from a 64-bit value.
Definition: IRBuilder.h:318
static void instrumentMaskedLoadOrStore(AddressSanitizer *Pass, const DataLayout &DL, Type *IntptrTy, Value *Mask, Instruction *I, Value *Addr, unsigned Alignment, unsigned Granularity, uint32_t TypeSize, bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp)
Value * CreateOr(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1130
Constant * getAggregateElement(unsigned Elt) const
For aggregates (struct/array/vector) return the constant that corresponds to the specified element if...
Definition: Constants.cpp:338
Type * getScalarType() const
If this is a vector type, return the element type, otherwise return &#39;this&#39;.
Definition: Type.h:304
Value * getOperand(unsigned i_nocapture) const
static cl::opt< bool > ClInstrumentWrites("asan-instrument-writes", cl::desc("instrument write instructions"), cl::Hidden, cl::init(true))
bool isOSWindows() const
Tests whether the OS is Windows.
Definition: Triple.h:562
ExternalWeak linkage description.
Definition: GlobalValue.h:58
const BasicBlock & getEntryBlock() const
Definition: Function.h:626
an instruction for type-safe pointer arithmetic to access elements of arrays and structs ...
Definition: Instructions.h:841
LoadInst * CreateLoad(Value *Ptr, const char *Name)
Provided to resolve &#39;CreateLoad(Ptr, "...")&#39; correctly, instead of converting the string to &#39;bool&#39; fo...
Definition: IRBuilder.h:1305
static const size_t kNumberOfAccessSizes
static MDTuple * get(LLVMContext &Context, ArrayRef< Metadata *> MDs)
Definition: Metadata.h:1164
static bool runOnFunction(Function &F, bool PostInlining)
static const char *const kAsanGlobalsRegisteredFlagName
initializer< Ty > init(const Ty &Val)
Definition: CommandLine.h:410
No other Module may specify this COMDAT.
Definition: Comdat.h:38
static const char *const kAsanPtrCmp
uint64_t getZExtValue() const
Return the constant as a 64-bit unsigned integer value after it has been zero extended as appropriate...
Definition: Constants.h:149
static std::string ParseSectionSpecifier(StringRef Spec, StringRef &Segment, StringRef &Section, unsigned &TAA, bool &TAAParsed, unsigned &StubSize)
Parse the section specifier indicated by "Spec".
Subclasses of this class are all able to terminate a basic block.
Definition: InstrTypes.h:55
* if(!EatIfPresent(lltok::kw_thread_local)) return false
ParseOptionalThreadLocal := /*empty.
const_iterator getFirstInsertionPt() const
Returns an iterator to the first instruction in this block that is suitable for inserting a non-PHI i...
Definition: BasicBlock.cpp:218
void setDebugLoc(DebugLoc Loc)
Set the debug location information for this instruction.
Definition: Instruction.h:287
DLLStorageClassTypes getDLLStorageClass() const
Definition: GlobalValue.h:258
std::size_t countTrailingZeros(T Val, ZeroBehavior ZB=ZB_Width)
Count number of 0&#39;s from the least significant bit to the most stopping at the first 1...
Definition: MathExtras.h:120
VisibilityTypes getVisibility() const
Definition: GlobalValue.h:232
constexpr bool isPowerOf2_32(uint32_t Value)
Return true if the argument is a power of two > 0.
Definition: MathExtras.h:429
bool hasName() const
Definition: Value.h:251
LLVM Basic Block Representation.
Definition: BasicBlock.h:59
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
std::pair< Function *, Function * > createSanitizerCtorAndInitFunctions(Module &M, StringRef CtorName, StringRef InitName, ArrayRef< Type *> InitArgTypes, ArrayRef< Value *> InitArgs, StringRef VersionCheckName=StringRef())
Creates sanitizer constructor function, and calls sanitizer&#39;s init function from it.
VendorType getVendor() const
getVendor - Get the parsed vendor type of this triple.
Definition: Triple.h:291
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:69
DISubprogram * getSubprogram() const
Get the attached subprogram.
Definition: Metadata.cpp:1508
Constant * getOrInsertGlobal(StringRef Name, Type *Ty)
Look up the specified global in the module symbol table.
Definition: Module.cpp:202
Conditional or Unconditional Branch instruction.
static const size_t kMinStackMallocSize
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:149
This function has undefined behavior.
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
This is an important base class in LLVM.
Definition: Constant.h:42
Resume the propagation of an exception.
static const char *const kAsanInitName
static const char *const kAsanStackFreeNameTemplate
static const uint64_t kNetBSD_ShadowOffset32
This file contains the declarations for the subclasses of Constant, which represent the different fla...
Value * CreateSelect(Value *C, Value *True, Value *False, const Twine &Name="", Instruction *MDFrom=nullptr)
Definition: IRBuilder.h:1901
bool isPointerTy() const
True if this is an instance of PointerType.
Definition: Type.h:224
static const uint64_t kMIPS32_ShadowOffset32
const Instruction & front() const
Definition: BasicBlock.h:276
static const char *const kAsanOptionDetectUseAfterReturn
std::pair< iterator, bool > insert(PtrType Ptr)
Inserts Ptr if and only if there is no element in the container equal to Ptr.
Definition: SmallPtrSet.h:371
static const uint64_t kFreeBSD_ShadowOffset32
static const uint64_t kAArch64_ShadowOffset64
static cl::opt< bool > ClInstrumentReads("asan-instrument-reads", cl::desc("instrument read instructions"), cl::Hidden, cl::init(true))
Represent the analysis usage information of a pass.
static Type * getVoidTy(LLVMContext &C)
Definition: Type.cpp:161
bool isAndroidVersionLT(unsigned Major) const
Definition: Triple.h:623
bool isPS4CPU() const
Tests whether the target is the PS4 CPU.
Definition: Triple.h:608
This instruction compares its operands according to the predicate given to the constructor.
Value * CreateICmpSGE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1764
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:285
static FunctionType * get(Type *Result, ArrayRef< Type *> Params, bool isVarArg)
This static method is the primary way of constructing a FunctionType.
Definition: Type.cpp:297
static Constant * get(StructType *T, ArrayRef< Constant *> V)
Definition: Constants.cpp:1021
op_range operands()
Definition: User.h:238
static BasicBlock * Create(LLVMContext &Context, const Twine &Name="", Function *Parent=nullptr, BasicBlock *InsertBefore=nullptr)
Creates a new BasicBlock.
Definition: BasicBlock.h:101
Value * CreateICmpEQ(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1736
ASanStackFrameLayout ComputeASanStackFrameLayout(SmallVectorImpl< ASanStackVariableDescription > &Vars, size_t Granularity, size_t MinHeaderSize)
size_type count(ConstPtrType Ptr) const
count - Return 1 if the specified pointer is in the set, 0 otherwise.
Definition: SmallPtrSet.h:382
static cl::opt< bool > ClOptGlobals("asan-opt-globals", cl::desc("Don't instrument scalar globals"), cl::Hidden, cl::init(true))
static cl::opt< bool > ClUseGlobalsGC("asan-globals-live-support", cl::desc("Use linker features to support dead " "code stripping of globals"), cl::Hidden, cl::init(true))
static const uintptr_t kRetiredStackFrameMagic
llvm::Expected< Value > parse(llvm::StringRef JSON)
Parses the provided JSON source, or returns a ParseError.
Definition: JSON.cpp:505
Value * CreateExtractElement(Value *Vec, Value *Idx, const Twine &Name="")
Definition: IRBuilder.h:1921
static const uint64_t kMyriadShadowScale
static cl::opt< bool > ClUsePrivateAliasForGlobals("asan-use-private-alias", cl::desc("Use private aliases for global" " variables"), cl::Hidden, cl::init(false))
static const char *const kAsanGenPrefix
std::string getUniqueModuleId(Module *M)
Produce a unique identifier for this module by taking the MD5 sum of the names of the module&#39;s strong...
static const char *const kAsanPtrSub
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)
S_CSTRING_LITERALS - Section with literal C strings.
Definition: MachO.h:124
Comdat * getOrInsertComdat(StringRef Name)
Return the Comdat in the module with the specified name.
Definition: Module.cpp:474
const Value * stripPointerCasts() const
Strip off pointer casts, all-zero GEPs, and aliases.
Definition: Value.cpp:539
iterator_range< User::op_iterator > arg_operands()
Iteration adapter for range-for loops.
static cl::opt< bool > ClGlobals("asan-globals", cl::desc("Handle global objects"), cl::Hidden, cl::init(true))
static cl::opt< uint32_t > ClMaxInlinePoisoningSize("asan-max-inline-poisoning-size", cl::desc("Inline shadow poisoning for blocks up to the given size in bytes."), cl::Hidden, cl::init(64))
const Value * getArraySize() const
Get the number of elements allocated.
Definition: Instructions.h:93
std::pair< APInt, APInt > SizeOffsetType
size_t size() const
Definition: SmallVector.h:53
static wasm::ValType getType(const TargetRegisterClass *RC)
PointerType * getInt8PtrTy(unsigned AddrSpace=0)
Fetch the type representing a pointer to an 8-bit integer value.
Definition: IRBuilder.h:385
const std::string & getModuleIdentifier() const
Get the module identifier which is, essentially, the name of the module.
Definition: Module.h:208
MDNode * createBranchWeights(uint32_t TrueWeight, uint32_t FalseWeight)
Return metadata containing two branch weights.
Definition: MDBuilder.cpp:38
static const uint64_t kWindowsShadowOffset32
Value * GetUnderlyingObject(Value *V, const DataLayout &DL, unsigned MaxLookup=6)
This method strips off any GEP address adjustments and pointer casts from the specified value...
INITIALIZE_PASS_END(RegBankSelect, DEBUG_TYPE, "Assign register bank of generic virtual registers", false, false) RegBankSelect
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
void initializeAddressSanitizerPass(PassRegistry &)
Value * CreateMul(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:996
static cl::opt< bool > ClWithComdat("asan-with-comdat", cl::desc("Place ASan constructors in comdat sections"), cl::Hidden, cl::init(true))
Type * getAllocatedType() const
Return the type that is being allocated by the instruction.
Definition: Instructions.h:106
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:44
static const char *const kAsanRegisterGlobalsName
Intrinsic::ID getIntrinsicID() const
Return the intrinsic ID of this intrinsic.
Definition: IntrinsicInst.h:51
PHINode * CreatePHI(Type *Ty, unsigned NumReservedValues, const Twine &Name="")
Definition: IRBuilder.h:1866
Value * CreateGEP(Value *Ptr, ArrayRef< Value *> IdxList, const Twine &Name="")
Definition: IRBuilder.h:1374
static Constant * getPointerCast(Constant *C, Type *Ty)
Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant expression.
Definition: Constants.cpp:1564
static const uint64_t kDynamicShadowSentinel
static IntegerType * get(LLVMContext &C, unsigned NumBits)
This static method is the primary way of constructing an IntegerType.
Definition: Type.cpp:240
static cl::opt< int > ClDebugMax("asan-debug-max", cl::desc("Debug max inst"), cl::Hidden, cl::init(-1))
print lazy value Lazy Value Info Printer Pass
This is the common base class for memset/memcpy/memmove.
uint64_t getLimitedValue(uint64_t Limit=~0ULL) const
getLimitedValue - If the value is smaller than the specified limit, return it, otherwise return the l...
Definition: Constants.h:251
This is the shared class of boolean and integer constants.
Definition: Constants.h:84
void setSelectionKind(SelectionKind Val)
Definition: Comdat.h:46
static const char *const kAsanStackMallocNameTemplate
static const char *const kAsanUnpoisonStackMemoryName
Evaluate the size and offset of an object pointed to by a Value* statically.
Value * CreateIntCast(Value *V, Type *DestTy, bool isSigned, const Twine &Name="")
Definition: IRBuilder.h:1698
static ValueAsMetadata * get(Value *V)
Definition: Metadata.cpp:349
bool hasSection() const
Check if this global has a custom object file section.
Definition: GlobalObject.h:82
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:847
static size_t TypeSizeToSizeIndex(uint32_t TypeSize)
Module.h This file contains the declarations for the Module class.
Provides information about what library functions are available for the current target.
unsigned getABITypeAlignment(Type *Ty) const
Returns the minimum ABI-required alignment for the specified type.
Definition: DataLayout.cpp:722
const DataFlowGraph & G
Definition: RDFGraph.cpp:211
bool isOSLinux() const
Tests whether the OS is Linux.
Definition: Triple.h:572
TerminatorInst * SplitBlockAndInsertIfThen(Value *Cond, Instruction *SplitBefore, bool Unreachable, MDNode *BranchWeights=nullptr, DominatorTree *DT=nullptr, LoopInfo *LI=nullptr)
Split the containing block at the specified instruction - everything before SplitBefore stays in the ...
static const uint64_t kDefaultShadowOffset64
ConstantInt * getInt32(uint32_t C)
Get a constant 32-bit value.
Definition: IRBuilder.h:307
static IntegerType * getIntNTy(LLVMContext &C, unsigned N)
Definition: Type.cpp:180
static cl::opt< int > ClDebugStack("asan-debug-stack", cl::desc("debug stack"), cl::Hidden, cl::init(0))
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
CallInst * CreateMemCpy(Value *Dst, unsigned DstAlign, Value *Src, unsigned SrcAlign, uint64_t Size, bool isVolatile=false, MDNode *TBAATag=nullptr, MDNode *TBAAStructTag=nullptr, MDNode *ScopeTag=nullptr, MDNode *NoAliasTag=nullptr)
Create and insert a memcpy between the specified pointers.
Definition: IRBuilder.h:446
static Constant * get(Type *Ty, uint64_t V, bool isSigned=false)
If Ty is a vector type, return a Constant with a splat of the given value.
Definition: Constants.cpp:621
static BranchInst * Create(BasicBlock *IfTrue, Instruction *InsertBefore=nullptr)
void appendToGlobalCtors(Module &M, Function *F, int Priority, Constant *Data=nullptr)
Append F to the list of global ctors of module M with the given Priority.
Definition: ModuleUtils.cpp:84
static cl::opt< bool > ClInvalidPointerPairs("asan-detect-invalid-pointer-pair", cl::desc("Instrument <, <=, >, >=, - with pointer operands"), cl::Hidden, cl::init(false))
static bool isPointerOperand(Value *V)
static cl::opt< int > ClInstrumentationWithCallsThreshold("asan-instrumentation-with-call-threshold", cl::desc("If the function being instrumented contains more than " "this number of memory accesses, use callbacks instead of " "inline checks (-1 means never use callbacks)."), cl::Hidden, cl::init(7000))
void setLinkage(LinkageTypes LT)
Definition: GlobalValue.h:444
bool isOSFreeBSD() const
Definition: Triple.h:486
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:133
Function * getFunction(StringRef Name) const
Look up the specified function in the module symbol table.
Definition: Module.cpp:172
SizeOffsetType compute(Value *V)
const Module * getModule() const
Return the module owning the function this instruction belongs to or nullptr it the function does not...
Definition: Instruction.cpp:56
ConstantArray - Constant Array Declarations.
Definition: Constants.h:410
static StringRef dropLLVMManglingEscape(StringRef Name)
If the given string begins with the GlobalValue name mangling escape character &#39;\1&#39;, drop it.
Definition: GlobalValue.h:471
static const uint64_t kSystemZ_ShadowOffset64
static GlobalVariable * createPrivateGlobalForSourceLoc(Module &M, LocationMetadata MD)
Create a global describing a source location.
LinkageTypes
An enumeration for the kinds of linkage for global values.
Definition: GlobalValue.h:48
static cl::opt< bool > ClWithIfuncSuppressRemat("asan-with-ifunc-suppress-remat", cl::desc("Suppress rematerialization of dynamic shadow address by passing " "it through inline asm in prologue."), cl::Hidden, cl::init(true))
IntegerType * getInt8Ty()
Fetch the type representing an 8-bit integer.
Definition: IRBuilder.h:337
Value * CreatePointerCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1675
bool hasComdat() const
Definition: GlobalObject.h:100
void setMetadata(unsigned KindID, MDNode *MD)
Set a particular kind of metadata attachment.
Definition: Metadata.cpp:1434
amdgpu Simplify well known AMD library false Value Value * Arg
static cl::opt< bool > ClSkipPromotableAllocas("asan-skip-promotable-allocas", cl::desc("Do not instrument promotable allocas"), cl::Hidden, cl::init(true))
const Comdat * getComdat() const
Definition: GlobalObject.h:101
uint64_t getTypeAllocSize(Type *Ty) const
Returns the offset in bytes between successive objects of the specified type, including alignment pad...
Definition: DataLayout.h:428
bool isMIPS32() const
Tests whether the target is MIPS 32-bit (little and big endian).
Definition: Triple.h:664
static const uint64_t kMyriadMemorySize32
static cl::opt< int > ClDebugMin("asan-debug-min", cl::desc("Debug min inst"), cl::Hidden, cl::init(-1))
static cl::opt< std::string > ClMemoryAccessCallbackPrefix("asan-memory-access-callback-prefix", cl::desc("Prefix for memory access callbacks"), cl::Hidden, cl::init("__asan_"))
const DebugLoc & getDebugLoc() const
Return the debug location for this node as a DebugLoc.
Definition: Instruction.h:290
bool isInlineAsm() const
Check if this call is an inline asm statement.
static const uint64_t kMIPS64_ShadowOffset64
void setUnnamedAddr(UnnamedAddr Val)
Definition: GlobalValue.h:215
static const size_t npos
Definition: StringRef.h:51
static IntegerType * getInt32Ty(LLVMContext &C)
Definition: Type.cpp:176
bool isThumb() const
Tests whether the target is Thumb (little and big endian).
Definition: Triple.h:649
static int StackMallocSizeClass(uint64_t LocalStackSize)
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:56
unsigned getNumArgOperands() const
Return the number of call arguments.
static cl::opt< uint32_t > ClForceExperiment("asan-force-experiment", cl::desc("Force optimization experiment (for testing)"), cl::Hidden, cl::init(0))
static const char *const kAsanRegisterElfGlobalsName
uint64_t getLimitedValue(uint64_t Limit=UINT64_MAX) const
If this value is smaller than the specified limit, return it, otherwise return the limit value...
Definition: APInt.h:482
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:224
void copyAttributesFrom(const GlobalVariable *Src)
copyAttributesFrom - copy all additional attributes (those not needed to create a GlobalVariable) fro...
Definition: Globals.cpp:381
const Function * getParent() const
Return the enclosing method, or null if none.
Definition: BasicBlock.h:108
static cl::opt< bool > ClDynamicAllocaStack("asan-stack-dynamic-alloca", cl::desc("Use dynamic alloca to represent stack variables"), cl::Hidden, cl::init(true))
#define I(x, y, z)
Definition: MD5.cpp:58
#define N
ModulePass class - This class is used to implement unstructured interprocedural optimizations and ana...
Definition: Pass.h:225
static ArrayType * get(Type *ElementType, uint64_t NumElements)
This static method is the primary way to construct an ArrayType.
Definition: Type.cpp:568
LLVM_NODISCARD std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type dyn_cast(const Y &Val)
Definition: Casting.h:323
Type * getValueType() const
Definition: GlobalValue.h:275
const BasicBlockListType & getBasicBlockList() const
Get the underlying elements of the Function...
Definition: Function.h:619
static const uint64_t kNetBSD_ShadowOffset64
Rename collisions when linking (static functions).
Definition: GlobalValue.h:56
void maybeMarkSanitizerLibraryCallNoBuiltin(CallInst *CI, const TargetLibraryInfo *TLI)
Given a CallInst, check if it calls a string function known to CodeGen, and mark it with NoBuiltin if...
Definition: Local.cpp:2768
static InlineAsm * get(FunctionType *Ty, StringRef AsmString, StringRef Constraints, bool hasSideEffects, bool isAlignStack=false, AsmDialect asmDialect=AD_ATT)
InlineAsm::get - Return the specified uniqued inline asm string.
Definition: InlineAsm.cpp:43
static const uint64_t kPS4CPU_ShadowOffset64
static const char *const kAsanModuleDtorName
Value * CreateAnd(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1112
Value * CreatePtrToInt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1619
const std::string to_string(const T &Value)
Definition: ScopedPrinter.h:62
static uint64_t getAllocaSizeInBytes(const AllocaInst &AI)
static const char *const kAsanUnregisterGlobalsName
iterator_range< df_iterator< T > > depth_first(const T &G)
static const char *const kAsanUnpoisonGlobalsName
bool isArrayAllocation() const
Return true if there is an allocation size parameter to the allocation instruction that is not 1...
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
const BasicBlock & front() const
Definition: Function.h:649
static bool bothKnown(const SizeOffsetType &SizeOffset)
Value * getArgOperand(unsigned i) const
getArgOperand/setArgOperand - Return/set the i-th call argument.
static const char *const kAsanPoisonGlobalsName
Module * getParent()
Get the module that this global value is contained inside of...
Definition: GlobalValue.h:565
LLVM Value Representation.
Definition: Value.h:73
void setAlignment(unsigned Align)
INITIALIZE_PASS(AddressSanitizerModule, "asan-module", "AddressSanitizer: detects use-after-free and out-of-bounds bugs." "ModulePass", false, false) ModulePass *llvm
static const uint64_t kPPC64_ShadowOffset64
static const unsigned kAllocaRzSize
bool hasInitializer() const
Definitions have initializers, declarations don&#39;t.
constexpr char Size[]
Key for Kernel::Arg::Metadata::mSize.
static cl::opt< bool > ClRedzoneByvalArgs("asan-redzone-byval-args", cl::desc("Create redzones for byval " "arguments (extra copy " "required)"), cl::Hidden, cl::init(true))
static cl::opt< bool > ClInstrumentAtomics("asan-instrument-atomics", cl::desc("instrument atomic instructions (rmw, cmpxchg)"), cl::Hidden, cl::init(true))
static const char *const kAsanUnregisterImageGlobalsName
std::underlying_type< E >::type Mask()
Get a bitmask with 1s in all places up to the high-order bit of E&#39;s largest value.
Definition: BitmaskEnum.h:81
static const Function * getParent(const Value *V)
void moveBefore(Instruction *MovePos)
Unlink this instruction from its current basic block and insert it into the basic block that MovePos ...
Definition: Instruction.cpp:87
bool isAndroid() const
Tests whether the target is Android.
Definition: Triple.h:621
static const char *const kAsanRegisterImageGlobalsName
static Constant * getAnon(ArrayRef< Constant *> V, bool Packed=false)
Return an anonymous struct that has the specified elements.
Definition: Constants.h:465
Value * CreateLShr(Value *LHS, Value *RHS, const Twine &Name="", bool isExact=false)
Definition: IRBuilder.h:1072
void addDebugInfo(DIGlobalVariableExpression *GV)
Attach a DIGlobalVariableExpression.
Definition: Metadata.cpp:1521
bool isThreadLocal() const
If the value is "Thread Local", its value isn&#39;t shared by the threads.
Definition: GlobalValue.h:246
FunctionPass * createAddressSanitizerFunctionPass(bool CompileKernel=false, bool Recover=false, bool UseAfterScope=false)
static const char *const kAsanAllocaPoison
static const char *const kAsanHandleNoReturnName
iterator_range< global_iterator > globals()
Definition: Module.h:573
IRTranslator LLVM IR MI
static const size_t kMaxStackMallocSize
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
Various options to control the behavior of getObjectSize.
A single uniqued string.
Definition: Metadata.h:602
static Function * Create(FunctionType *Ty, LinkageTypes Linkage, const Twine &N="", Module *M=nullptr)
Definition: Function.h:136
Legacy analysis pass which computes a DominatorTree.
Definition: Dominators.h:254
static cl::opt< bool > ClOptStack("asan-opt-stack", cl::desc("Don't instrument scalar stack variables"), cl::Hidden, cl::init(false))
bool isStaticAlloca() const
Return true if this alloca is in the entry block of the function and is a constant size...
static const char *const kAsanVersionCheckNamePrefix
static cl::opt< unsigned > ClRealignStack("asan-realign-stack", cl::desc("Realign stack to the value of this flag (power of two)"), cl::Hidden, cl::init(32))
unsigned getNumOperands() const
Return number of MDNode operands.
Definition: Metadata.h:1073
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE size_t find(char C, size_t From=0) const
Search for the first character C in the string.
Definition: StringRef.h:298
#define LLVM_DEBUG(X)
Definition: Debug.h:119
ModulePass * createAddressSanitizerModulePass(bool CompileKernel=false, bool Recover=false, bool UseGlobalsGC=true)
Root of the metadata hierarchy.
Definition: Metadata.h:58
static cl::opt< bool > ClInstrumentDynamicAllocas("asan-instrument-dynamic-allocas", cl::desc("instrument dynamic allocas"), cl::Hidden, cl::init(true))
const uint64_t Version
Definition: InstrProf.h:895
void setSection(StringRef S)
Change the section for this global.
Definition: Globals.cpp:184
#define OP(n)
Definition: regex2.h:73
static GlobalAlias * create(Type *Ty, unsigned AddressSpace, LinkageTypes Linkage, const Twine &Name, Constant *Aliasee, Module *Parent)
If a parent module is specified, the alias is automatically inserted into the end of the specified mo...
Definition: Globals.cpp:418
bool isARM() const
Tests whether the target is ARM (little and big endian).
Definition: Triple.h:654
std::vector< uint32_t > Metadata
PAL metadata represented as a vector.
iterator_range< arg_iterator > args()
Definition: Function.h:675
A wrapper class for inspecting calls to intrinsic functions.
Definition: IntrinsicInst.h:44
const BasicBlock * getParent() const
Definition: Instruction.h:67
an instruction to allocate memory on the stack
Definition: Instructions.h:60
SmallVector< uint8_t, 64 > GetShadowBytes(const SmallVectorImpl< ASanStackVariableDescription > &Vars, const ASanStackFrameLayout &Layout)
static const char *const kAsanReportErrorTemplate
CallInst * CreateCall(Value *Callee, ArrayRef< Value *> Args=None, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:1871
void resize(size_type N)
Definition: SmallVector.h:351