LLVM  8.0.0svn
AddressSanitizer.cpp
Go to the documentation of this file.
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"
30 #include "llvm/IR/Argument.h"
31 #include "llvm/IR/Attributes.h"
32 #include "llvm/IR/BasicBlock.h"
33 #include "llvm/IR/CallSite.h"
34 #include "llvm/IR/Comdat.h"
35 #include "llvm/IR/Constant.h"
36 #include "llvm/IR/Constants.h"
37 #include "llvm/IR/DIBuilder.h"
38 #include "llvm/IR/DataLayout.h"
40 #include "llvm/IR/DebugLoc.h"
41 #include "llvm/IR/DerivedTypes.h"
42 #include "llvm/IR/Dominators.h"
43 #include "llvm/IR/Function.h"
44 #include "llvm/IR/GlobalAlias.h"
45 #include "llvm/IR/GlobalValue.h"
46 #include "llvm/IR/GlobalVariable.h"
47 #include "llvm/IR/IRBuilder.h"
48 #include "llvm/IR/InlineAsm.h"
49 #include "llvm/IR/InstVisitor.h"
50 #include "llvm/IR/InstrTypes.h"
51 #include "llvm/IR/Instruction.h"
52 #include "llvm/IR/Instructions.h"
53 #include "llvm/IR/IntrinsicInst.h"
54 #include "llvm/IR/Intrinsics.h"
55 #include "llvm/IR/LLVMContext.h"
56 #include "llvm/IR/MDBuilder.h"
57 #include "llvm/IR/Metadata.h"
58 #include "llvm/IR/Module.h"
59 #include "llvm/IR/Type.h"
60 #include "llvm/IR/Use.h"
61 #include "llvm/IR/Value.h"
62 #include "llvm/MC/MCSectionMachO.h"
63 #include "llvm/Pass.h"
64 #include "llvm/Support/Casting.h"
66 #include "llvm/Support/Debug.h"
78 #include <algorithm>
79 #include <cassert>
80 #include <cstddef>
81 #include <cstdint>
82 #include <iomanip>
83 #include <limits>
84 #include <memory>
85 #include <sstream>
86 #include <string>
87 #include <tuple>
88 
89 using namespace llvm;
90 
91 #define DEBUG_TYPE "asan"
92 
93 static const uint64_t kDefaultShadowScale = 3;
94 static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
95 static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
96 static const uint64_t kDynamicShadowSentinel =
98 static const uint64_t kIOSShadowOffset32 = 1ULL << 30;
99 static const uint64_t kIOSSimShadowOffset32 = 1ULL << 30;
101 static const uint64_t kSmallX86_64ShadowOffsetBase = 0x7FFFFFFF; // < 2G.
102 static const uint64_t kSmallX86_64ShadowOffsetAlignMask = ~0xFFFULL;
103 static const uint64_t kLinuxKasan_ShadowOffset64 = 0xdffffc0000000000;
104 static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 44;
105 static const uint64_t kSystemZ_ShadowOffset64 = 1ULL << 52;
106 static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa0000;
107 static const uint64_t kMIPS64_ShadowOffset64 = 1ULL << 37;
108 static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 36;
109 static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
110 static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
111 static const uint64_t kNetBSD_ShadowOffset32 = 1ULL << 30;
112 static const uint64_t kNetBSD_ShadowOffset64 = 1ULL << 46;
113 static const uint64_t kPS4CPU_ShadowOffset64 = 1ULL << 40;
114 static const uint64_t kWindowsShadowOffset32 = 3ULL << 28;
115 
116 static const uint64_t kMyriadShadowScale = 5;
117 static const uint64_t kMyriadMemoryOffset32 = 0x80000000ULL;
118 static const uint64_t kMyriadMemorySize32 = 0x20000000ULL;
119 static const uint64_t kMyriadTagShift = 29;
120 static const uint64_t kMyriadDDRTag = 4;
121 static const uint64_t kMyriadCacheBitMask32 = 0x40000000ULL;
122 
123 // The shadow memory space is dynamically allocated.
125 
126 static const size_t kMinStackMallocSize = 1 << 6; // 64B
127 static const size_t kMaxStackMallocSize = 1 << 16; // 64K
128 static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
129 static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;
130 
131 static const char *const kAsanModuleCtorName = "asan.module_ctor";
132 static const char *const kAsanModuleDtorName = "asan.module_dtor";
133 static const uint64_t kAsanCtorAndDtorPriority = 1;
134 static const char *const kAsanReportErrorTemplate = "__asan_report_";
135 static const char *const kAsanRegisterGlobalsName = "__asan_register_globals";
136 static const char *const kAsanUnregisterGlobalsName =
137  "__asan_unregister_globals";
138 static const char *const kAsanRegisterImageGlobalsName =
139  "__asan_register_image_globals";
140 static const char *const kAsanUnregisterImageGlobalsName =
141  "__asan_unregister_image_globals";
142 static const char *const kAsanRegisterElfGlobalsName =
143  "__asan_register_elf_globals";
144 static const char *const kAsanUnregisterElfGlobalsName =
145  "__asan_unregister_elf_globals";
146 static const char *const kAsanPoisonGlobalsName = "__asan_before_dynamic_init";
147 static const char *const kAsanUnpoisonGlobalsName = "__asan_after_dynamic_init";
148 static const char *const kAsanInitName = "__asan_init";
149 static const char *const kAsanVersionCheckNamePrefix =
150  "__asan_version_mismatch_check_v";
151 static const char *const kAsanPtrCmp = "__sanitizer_ptr_cmp";
152 static const char *const kAsanPtrSub = "__sanitizer_ptr_sub";
153 static const char *const kAsanHandleNoReturnName = "__asan_handle_no_return";
154 static const int kMaxAsanStackMallocSizeClass = 10;
155 static const char *const kAsanStackMallocNameTemplate = "__asan_stack_malloc_";
156 static const char *const kAsanStackFreeNameTemplate = "__asan_stack_free_";
157 static const char *const kAsanGenPrefix = "___asan_gen_";
158 static const char *const kODRGenPrefix = "__odr_asan_gen_";
159 static const char *const kSanCovGenPrefix = "__sancov_gen_";
160 static const char *const kAsanSetShadowPrefix = "__asan_set_shadow_";
161 static const char *const kAsanPoisonStackMemoryName =
162  "__asan_poison_stack_memory";
163 static const char *const kAsanUnpoisonStackMemoryName =
164  "__asan_unpoison_stack_memory";
165 
166 // ASan version script has __asan_* wildcard. Triple underscore prevents a
167 // linker (gold) warning about attempting to export a local symbol.
168 static const char *const kAsanGlobalsRegisteredFlagName =
169  "___asan_globals_registered";
170 
171 static const char *const kAsanOptionDetectUseAfterReturn =
172  "__asan_option_detect_stack_use_after_return";
173 
174 static const char *const kAsanShadowMemoryDynamicAddress =
175  "__asan_shadow_memory_dynamic_address";
176 
177 static const char *const kAsanAllocaPoison = "__asan_alloca_poison";
178 static const char *const kAsanAllocasUnpoison = "__asan_allocas_unpoison";
179 
180 // Accesses sizes are powers of two: 1, 2, 4, 8, 16.
181 static const size_t kNumberOfAccessSizes = 5;
182 
183 static const unsigned kAllocaRzSize = 32;
184 
185 // Command-line flags.
186 
188  "asan-kernel", cl::desc("Enable KernelAddressSanitizer instrumentation"),
189  cl::Hidden, cl::init(false));
190 
191 static cl::opt<bool> ClRecover(
192  "asan-recover",
193  cl::desc("Enable recovery mode (continue-after-error)."),
194  cl::Hidden, cl::init(false));
195 
196 // This flag may need to be replaced with -f[no-]asan-reads.
197 static cl::opt<bool> ClInstrumentReads("asan-instrument-reads",
198  cl::desc("instrument read instructions"),
199  cl::Hidden, cl::init(true));
200 
202  "asan-instrument-writes", cl::desc("instrument write instructions"),
203  cl::Hidden, cl::init(true));
204 
206  "asan-instrument-atomics",
207  cl::desc("instrument atomic instructions (rmw, cmpxchg)"), cl::Hidden,
208  cl::init(true));
209 
211  "asan-always-slow-path",
212  cl::desc("use instrumentation with slow path for all accesses"), cl::Hidden,
213  cl::init(false));
214 
216  "asan-force-dynamic-shadow",
217  cl::desc("Load shadow address into a local variable for each function"),
218  cl::Hidden, cl::init(false));
219 
220 static cl::opt<bool>
221  ClWithIfunc("asan-with-ifunc",
222  cl::desc("Access dynamic shadow through an ifunc global on "
223  "platforms that support this"),
224  cl::Hidden, cl::init(true));
225 
227  "asan-with-ifunc-suppress-remat",
228  cl::desc("Suppress rematerialization of dynamic shadow address by passing "
229  "it through inline asm in prologue."),
230  cl::Hidden, cl::init(true));
231 
232 // This flag limits the number of instructions to be instrumented
233 // in any given BB. Normally, this should be set to unlimited (INT_MAX),
234 // but due to http://llvm.org/bugs/show_bug.cgi?id=12652 we temporary
235 // set it to 10000.
237  "asan-max-ins-per-bb", cl::init(10000),
238  cl::desc("maximal number of instructions to instrument in any given BB"),
239  cl::Hidden);
240 
241 // This flag may need to be replaced with -f[no]asan-stack.
242 static cl::opt<bool> ClStack("asan-stack", cl::desc("Handle stack memory"),
243  cl::Hidden, cl::init(true));
245  "asan-max-inline-poisoning-size",
246  cl::desc(
247  "Inline shadow poisoning for blocks up to the given size in bytes."),
248  cl::Hidden, cl::init(64));
249 
250 static cl::opt<bool> ClUseAfterReturn("asan-use-after-return",
251  cl::desc("Check stack-use-after-return"),
252  cl::Hidden, cl::init(true));
253 
254 static cl::opt<bool> ClRedzoneByvalArgs("asan-redzone-byval-args",
255  cl::desc("Create redzones for byval "
256  "arguments (extra copy "
257  "required)"), cl::Hidden,
258  cl::init(true));
259 
260 static cl::opt<bool> ClUseAfterScope("asan-use-after-scope",
261  cl::desc("Check stack-use-after-scope"),
262  cl::Hidden, cl::init(false));
263 
264 // This flag may need to be replaced with -f[no]asan-globals.
265 static cl::opt<bool> ClGlobals("asan-globals",
266  cl::desc("Handle global objects"), cl::Hidden,
267  cl::init(true));
268 
269 static cl::opt<bool> ClInitializers("asan-initialization-order",
270  cl::desc("Handle C++ initializer order"),
271  cl::Hidden, cl::init(true));
272 
274  "asan-detect-invalid-pointer-pair",
275  cl::desc("Instrument <, <=, >, >=, - with pointer operands"), cl::Hidden,
276  cl::init(false));
277 
279  "asan-realign-stack",
280  cl::desc("Realign stack to the value of this flag (power of two)"),
281  cl::Hidden, cl::init(32));
282 
284  "asan-instrumentation-with-call-threshold",
285  cl::desc(
286  "If the function being instrumented contains more than "
287  "this number of memory accesses, use callbacks instead of "
288  "inline checks (-1 means never use callbacks)."),
289  cl::Hidden, cl::init(7000));
290 
292  "asan-memory-access-callback-prefix",
293  cl::desc("Prefix for memory access callbacks"), cl::Hidden,
294  cl::init("__asan_"));
295 
296 static cl::opt<bool>
297  ClInstrumentDynamicAllocas("asan-instrument-dynamic-allocas",
298  cl::desc("instrument dynamic allocas"),
299  cl::Hidden, cl::init(true));
300 
302  "asan-skip-promotable-allocas",
303  cl::desc("Do not instrument promotable allocas"), cl::Hidden,
304  cl::init(true));
305 
306 // These flags allow to change the shadow mapping.
307 // The shadow mapping looks like
308 // Shadow = (Mem >> scale) + offset
309 
310 static cl::opt<int> ClMappingScale("asan-mapping-scale",
311  cl::desc("scale of asan shadow mapping"),
312  cl::Hidden, cl::init(0));
313 
315  "asan-mapping-offset",
316  cl::desc("offset of asan shadow mapping [EXPERIMENTAL]"), cl::Hidden,
317  cl::init(0));
318 
319 // Optimization flags. Not user visible, used mostly for testing
320 // and benchmarking the tool.
321 
322 static cl::opt<bool> ClOpt("asan-opt", cl::desc("Optimize instrumentation"),
323  cl::Hidden, cl::init(true));
324 
326  "asan-opt-same-temp", cl::desc("Instrument the same temp just once"),
327  cl::Hidden, cl::init(true));
328 
329 static cl::opt<bool> ClOptGlobals("asan-opt-globals",
330  cl::desc("Don't instrument scalar globals"),
331  cl::Hidden, cl::init(true));
332 
334  "asan-opt-stack", cl::desc("Don't instrument scalar stack variables"),
335  cl::Hidden, cl::init(false));
336 
338  "asan-stack-dynamic-alloca",
339  cl::desc("Use dynamic alloca to represent stack variables"), cl::Hidden,
340  cl::init(true));
341 
343  "asan-force-experiment",
344  cl::desc("Force optimization experiment (for testing)"), cl::Hidden,
345  cl::init(0));
346 
347 static cl::opt<bool>
348  ClUsePrivateAliasForGlobals("asan-use-private-alias",
349  cl::desc("Use private aliases for global"
350  " variables"),
351  cl::Hidden, cl::init(false));
352 
353 static cl::opt<bool>
354  ClUseGlobalsGC("asan-globals-live-support",
355  cl::desc("Use linker features to support dead "
356  "code stripping of globals"),
357  cl::Hidden, cl::init(true));
358 
359 // This is on by default even though there is a bug in gold:
360 // https://sourceware.org/bugzilla/show_bug.cgi?id=19002
361 static cl::opt<bool>
362  ClWithComdat("asan-with-comdat",
363  cl::desc("Place ASan constructors in comdat sections"),
364  cl::Hidden, cl::init(true));
365 
366 // Debug flags.
367 
368 static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
369  cl::init(0));
370 
371 static cl::opt<int> ClDebugStack("asan-debug-stack", cl::desc("debug stack"),
372  cl::Hidden, cl::init(0));
373 
374 static cl::opt<std::string> ClDebugFunc("asan-debug-func", cl::Hidden,
375  cl::desc("Debug func"));
376 
377 static cl::opt<int> ClDebugMin("asan-debug-min", cl::desc("Debug min inst"),
378  cl::Hidden, cl::init(-1));
379 
380 static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug max inst"),
381  cl::Hidden, cl::init(-1));
382 
383 STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
384 STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
385 STATISTIC(NumOptimizedAccessesToGlobalVar,
386  "Number of optimized accesses to global vars");
387 STATISTIC(NumOptimizedAccessesToStackVar,
388  "Number of optimized accesses to stack vars");
389 
390 namespace {
391 
392 /// Frontend-provided metadata for source location.
393 struct LocationMetadata {
394  StringRef Filename;
395  int LineNo = 0;
396  int ColumnNo = 0;
397 
398  LocationMetadata() = default;
399 
400  bool empty() const { return Filename.empty(); }
401 
402  void parse(MDNode *MDN) {
403  assert(MDN->getNumOperands() == 3);
404  MDString *DIFilename = cast<MDString>(MDN->getOperand(0));
405  Filename = DIFilename->getString();
406  LineNo =
407  mdconst::extract<ConstantInt>(MDN->getOperand(1))->getLimitedValue();
408  ColumnNo =
409  mdconst::extract<ConstantInt>(MDN->getOperand(2))->getLimitedValue();
410  }
411 };
412 
413 /// Frontend-provided metadata for global variables.
414 class GlobalsMetadata {
415 public:
416  struct Entry {
417  LocationMetadata SourceLoc;
418  StringRef Name;
419  bool IsDynInit = false;
420  bool IsBlacklisted = false;
421 
422  Entry() = default;
423  };
424 
425  GlobalsMetadata() = default;
426 
427  void reset() {
428  inited_ = false;
429  Entries.clear();
430  }
431 
432  void init(Module &M) {
433  assert(!inited_);
434  inited_ = true;
435  NamedMDNode *Globals = M.getNamedMetadata("llvm.asan.globals");
436  if (!Globals) return;
437  for (auto MDN : Globals->operands()) {
438  // Metadata node contains the global and the fields of "Entry".
439  assert(MDN->getNumOperands() == 5);
440  auto *GV = mdconst::extract_or_null<GlobalVariable>(MDN->getOperand(0));
441  // The optimizer may optimize away a global entirely.
442  if (!GV) continue;
443  // We can already have an entry for GV if it was merged with another
444  // global.
445  Entry &E = Entries[GV];
446  if (auto *Loc = cast_or_null<MDNode>(MDN->getOperand(1)))
447  E.SourceLoc.parse(Loc);
448  if (auto *Name = cast_or_null<MDString>(MDN->getOperand(2)))
449  E.Name = Name->getString();
450  ConstantInt *IsDynInit =
451  mdconst::extract<ConstantInt>(MDN->getOperand(3));
452  E.IsDynInit |= IsDynInit->isOne();
453  ConstantInt *IsBlacklisted =
454  mdconst::extract<ConstantInt>(MDN->getOperand(4));
455  E.IsBlacklisted |= IsBlacklisted->isOne();
456  }
457  }
458 
459  /// Returns metadata entry for a given global.
460  Entry get(GlobalVariable *G) const {
461  auto Pos = Entries.find(G);
462  return (Pos != Entries.end()) ? Pos->second : Entry();
463  }
464 
465 private:
466  bool inited_ = false;
468 };
469 
470 /// This struct defines the shadow mapping using the rule:
471 /// shadow = (mem >> Scale) ADD-or-OR Offset.
472 /// If InGlobal is true, then
473 /// extern char __asan_shadow[];
474 /// shadow = (mem >> Scale) + &__asan_shadow
475 struct ShadowMapping {
476  int Scale;
477  uint64_t Offset;
478  bool OrShadowOffset;
479  bool InGlobal;
480 };
481 
482 } // end anonymous namespace
483 
484 static ShadowMapping getShadowMapping(Triple &TargetTriple, int LongSize,
485  bool IsKasan) {
486  bool IsAndroid = TargetTriple.isAndroid();
487  bool IsIOS = TargetTriple.isiOS() || TargetTriple.isWatchOS();
488  bool IsFreeBSD = TargetTriple.isOSFreeBSD();
489  bool IsNetBSD = TargetTriple.isOSNetBSD();
490  bool IsPS4CPU = TargetTriple.isPS4CPU();
491  bool IsLinux = TargetTriple.isOSLinux();
492  bool IsPPC64 = TargetTriple.getArch() == Triple::ppc64 ||
493  TargetTriple.getArch() == Triple::ppc64le;
494  bool IsSystemZ = TargetTriple.getArch() == Triple::systemz;
495  bool IsX86 = TargetTriple.getArch() == Triple::x86;
496  bool IsX86_64 = TargetTriple.getArch() == Triple::x86_64;
497  bool IsMIPS32 = TargetTriple.isMIPS32();
498  bool IsMIPS64 = TargetTriple.isMIPS64();
499  bool IsArmOrThumb = TargetTriple.isARM() || TargetTriple.isThumb();
500  bool IsAArch64 = TargetTriple.getArch() == Triple::aarch64;
501  bool IsWindows = TargetTriple.isOSWindows();
502  bool IsFuchsia = TargetTriple.isOSFuchsia();
503  bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
504 
505  ShadowMapping Mapping;
506 
507  Mapping.Scale = IsMyriad ? kMyriadShadowScale : kDefaultShadowScale;
508  if (ClMappingScale.getNumOccurrences() > 0) {
509  Mapping.Scale = ClMappingScale;
510  }
511 
512  if (LongSize == 32) {
513  if (IsAndroid)
514  Mapping.Offset = kDynamicShadowSentinel;
515  else if (IsMIPS32)
516  Mapping.Offset = kMIPS32_ShadowOffset32;
517  else if (IsFreeBSD)
518  Mapping.Offset = kFreeBSD_ShadowOffset32;
519  else if (IsNetBSD)
520  Mapping.Offset = kNetBSD_ShadowOffset32;
521  else if (IsIOS)
522  // If we're targeting iOS and x86, the binary is built for iOS simulator.
523  Mapping.Offset = IsX86 ? kIOSSimShadowOffset32 : kIOSShadowOffset32;
524  else if (IsWindows)
525  Mapping.Offset = kWindowsShadowOffset32;
526  else if (IsMyriad) {
527  uint64_t ShadowOffset = (kMyriadMemoryOffset32 + kMyriadMemorySize32 -
528  (kMyriadMemorySize32 >> Mapping.Scale));
529  Mapping.Offset = ShadowOffset - (kMyriadMemoryOffset32 >> Mapping.Scale);
530  }
531  else
532  Mapping.Offset = kDefaultShadowOffset32;
533  } else { // LongSize == 64
534  // Fuchsia is always PIE, which means that the beginning of the address
535  // space is always available.
536  if (IsFuchsia)
537  Mapping.Offset = 0;
538  else if (IsPPC64)
539  Mapping.Offset = kPPC64_ShadowOffset64;
540  else if (IsSystemZ)
541  Mapping.Offset = kSystemZ_ShadowOffset64;
542  else if (IsFreeBSD && !IsMIPS64)
543  Mapping.Offset = kFreeBSD_ShadowOffset64;
544  else if (IsNetBSD)
545  Mapping.Offset = kNetBSD_ShadowOffset64;
546  else if (IsPS4CPU)
547  Mapping.Offset = kPS4CPU_ShadowOffset64;
548  else if (IsLinux && IsX86_64) {
549  if (IsKasan)
550  Mapping.Offset = kLinuxKasan_ShadowOffset64;
551  else
552  Mapping.Offset = (kSmallX86_64ShadowOffsetBase &
553  (kSmallX86_64ShadowOffsetAlignMask << Mapping.Scale));
554  } else if (IsWindows && IsX86_64) {
555  Mapping.Offset = kWindowsShadowOffset64;
556  } else if (IsMIPS64)
557  Mapping.Offset = kMIPS64_ShadowOffset64;
558  else if (IsIOS)
559  // If we're targeting iOS and x86, the binary is built for iOS simulator.
560  // We are using dynamic shadow offset on the 64-bit devices.
561  Mapping.Offset =
563  else if (IsAArch64)
564  Mapping.Offset = kAArch64_ShadowOffset64;
565  else
566  Mapping.Offset = kDefaultShadowOffset64;
567  }
568 
569  if (ClForceDynamicShadow) {
570  Mapping.Offset = kDynamicShadowSentinel;
571  }
572 
573  if (ClMappingOffset.getNumOccurrences() > 0) {
574  Mapping.Offset = ClMappingOffset;
575  }
576 
577  // OR-ing shadow offset if more efficient (at least on x86) if the offset
578  // is a power of two, but on ppc64 we have to use add since the shadow
579  // offset is not necessary 1/8-th of the address space. On SystemZ,
580  // we could OR the constant in a single instruction, but it's more
581  // efficient to load it once and use indexed addressing.
582  Mapping.OrShadowOffset = !IsAArch64 && !IsPPC64 && !IsSystemZ && !IsPS4CPU &&
583  !(Mapping.Offset & (Mapping.Offset - 1)) &&
584  Mapping.Offset != kDynamicShadowSentinel;
585  bool IsAndroidWithIfuncSupport =
586  IsAndroid && !TargetTriple.isAndroidVersionLT(21);
587  Mapping.InGlobal = ClWithIfunc && IsAndroidWithIfuncSupport && IsArmOrThumb;
588 
589  return Mapping;
590 }
591 
592 static size_t RedzoneSizeForScale(int MappingScale) {
593  // Redzone used for stack and globals is at least 32 bytes.
594  // For scales 6 and 7, the redzone has to be 64 and 128 bytes respectively.
595  return std::max(32U, 1U << MappingScale);
596 }
597 
598 namespace {
599 
600 /// AddressSanitizer: instrument the code in module to find memory bugs.
601 struct AddressSanitizer {
602  explicit AddressSanitizer(Module &M, DominatorTree *DT,
603  bool CompileKernel = false, bool Recover = false,
604  bool UseAfterScope = false)
605  : UseAfterScope(UseAfterScope || ClUseAfterScope), DT(DT) {
606  this->Recover = ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover;
607  this->CompileKernel = ClEnableKasan.getNumOccurrences() > 0 ?
608  ClEnableKasan : CompileKernel;
609 
610  // Initialize the private fields. No one has accessed them before.
611  GlobalsMD.init(M);
612  C = &(M.getContext());
613  LongSize = M.getDataLayout().getPointerSizeInBits();
614  IntptrTy = Type::getIntNTy(*C, LongSize);
615  TargetTriple = Triple(M.getTargetTriple());
616  Mapping = getShadowMapping(TargetTriple, LongSize, CompileKernel);
617  }
618 
619  uint64_t getAllocaSizeInBytes(const AllocaInst &AI) const {
620  uint64_t ArraySize = 1;
621  if (AI.isArrayAllocation()) {
622  const ConstantInt *CI = dyn_cast<ConstantInt>(AI.getArraySize());
623  assert(CI && "non-constant array size");
624  ArraySize = CI->getZExtValue();
625  }
626  Type *Ty = AI.getAllocatedType();
627  uint64_t SizeInBytes =
629  return SizeInBytes * ArraySize;
630  }
631 
632  /// Check if we want (and can) handle this alloca.
633  bool isInterestingAlloca(const AllocaInst &AI);
634 
635  /// If it is an interesting memory access, return the PointerOperand
636  /// and set IsWrite/Alignment. Otherwise return nullptr.
637  /// MaybeMask is an output parameter for the mask Value, if we're looking at a
638  /// masked load/store.
639  Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite,
640  uint64_t *TypeSize, unsigned *Alignment,
641  Value **MaybeMask = nullptr);
642 
643  void instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis, Instruction *I,
644  bool UseCalls, const DataLayout &DL);
645  void instrumentPointerComparisonOrSubtraction(Instruction *I);
646  void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
647  Value *Addr, uint32_t TypeSize, bool IsWrite,
648  Value *SizeArgument, bool UseCalls, uint32_t Exp);
649  void instrumentUnusualSizeOrAlignment(Instruction *I,
650  Instruction *InsertBefore, Value *Addr,
651  uint32_t TypeSize, bool IsWrite,
652  Value *SizeArgument, bool UseCalls,
653  uint32_t Exp);
654  Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
655  Value *ShadowValue, uint32_t TypeSize);
656  Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
657  bool IsWrite, size_t AccessSizeIndex,
658  Value *SizeArgument, uint32_t Exp);
659  void instrumentMemIntrinsic(MemIntrinsic *MI);
660  Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
661  bool maybeInsertAsanInitAtFunctionEntry(Function &F);
662  void maybeInsertDynamicShadowAtFunctionEntry(Function &F);
663  void markEscapedLocalAllocas(Function &F);
664 
665  /// Return true if the function changed.
666  bool instrument(Function &F, const TargetLibraryInfo *TLI);
667 
668  DominatorTree &getDominatorTree() const { return *DT; }
669 
670 private:
671  friend struct FunctionStackPoisoner;
672 
673  void initializeCallbacks(Module &M);
674 
675  bool LooksLikeCodeInBug11395(Instruction *I);
676  bool GlobalIsLinkerInitialized(GlobalVariable *G);
677  bool isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis, Value *Addr,
678  uint64_t TypeSize) const;
679 
680  /// Helper to cleanup per-function state.
681  struct FunctionStateRAII {
682  AddressSanitizer *Pass;
683 
684  FunctionStateRAII(AddressSanitizer *Pass) : Pass(Pass) {
685  assert(Pass->ProcessedAllocas.empty() &&
686  "last pass forgot to clear cache");
687  assert(!Pass->LocalDynamicShadow);
688  }
689 
690  ~FunctionStateRAII() {
691  Pass->LocalDynamicShadow = nullptr;
692  Pass->ProcessedAllocas.clear();
693  }
694  };
695 
696  LLVMContext *C;
697  Triple TargetTriple;
698  int LongSize;
699  bool CompileKernel;
700  bool Recover;
701  bool UseAfterScope;
702  Type *IntptrTy;
703  ShadowMapping Mapping;
704  DominatorTree *DT;
705  Function *AsanHandleNoReturnFunc;
706  Function *AsanPtrCmpFunction, *AsanPtrSubFunction;
707  Constant *AsanShadowGlobal;
708 
709  // These arrays is indexed by AccessIsWrite, Experiment and log2(AccessSize).
710  Function *AsanErrorCallback[2][2][kNumberOfAccessSizes];
711  Function *AsanMemoryAccessCallback[2][2][kNumberOfAccessSizes];
712 
713  // These arrays is indexed by AccessIsWrite and Experiment.
714  Function *AsanErrorCallbackSized[2][2];
715  Function *AsanMemoryAccessCallbackSized[2][2];
716 
717  Function *AsanMemmove, *AsanMemcpy, *AsanMemset;
718  InlineAsm *EmptyAsm;
719  Value *LocalDynamicShadow = nullptr;
720  GlobalsMetadata GlobalsMD;
721  DenseMap<const AllocaInst *, bool> ProcessedAllocas;
722 };
723 
724 class AddressSanitizerModule {
725 public:
726  explicit AddressSanitizerModule(bool CompileKernel = false,
727  bool Recover = false,
728  bool UseGlobalsGC = true)
729  : UseGlobalsGC(UseGlobalsGC && ClUseGlobalsGC),
730  // Not a typo: ClWithComdat is almost completely pointless without
731  // ClUseGlobalsGC (because then it only works on modules without
732  // globals, which are rare); it is a prerequisite for ClUseGlobalsGC;
733  // and both suffer from gold PR19002 for which UseGlobalsGC constructor
734  // argument is designed as workaround. Therefore, disable both
735  // ClWithComdat and ClUseGlobalsGC unless the frontend says it's ok to
736  // do globals-gc.
737  UseCtorComdat(UseGlobalsGC && ClWithComdat) {
738  this->Recover = ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover;
739  this->CompileKernel =
740  ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan : CompileKernel;
741  }
742 
743  bool instrument(Module &M);
744 
745 private:
746  void initializeCallbacks(Module &M);
747 
748  bool InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat);
749  void InstrumentGlobalsCOFF(IRBuilder<> &IRB, Module &M,
750  ArrayRef<GlobalVariable *> ExtendedGlobals,
751  ArrayRef<Constant *> MetadataInitializers);
752  void InstrumentGlobalsELF(IRBuilder<> &IRB, Module &M,
753  ArrayRef<GlobalVariable *> ExtendedGlobals,
754  ArrayRef<Constant *> MetadataInitializers,
755  const std::string &UniqueModuleId);
756  void InstrumentGlobalsMachO(IRBuilder<> &IRB, Module &M,
757  ArrayRef<GlobalVariable *> ExtendedGlobals,
758  ArrayRef<Constant *> MetadataInitializers);
759  void
760  InstrumentGlobalsWithMetadataArray(IRBuilder<> &IRB, Module &M,
761  ArrayRef<GlobalVariable *> ExtendedGlobals,
762  ArrayRef<Constant *> MetadataInitializers);
763 
764  GlobalVariable *CreateMetadataGlobal(Module &M, Constant *Initializer,
765  StringRef OriginalName);
766  void SetComdatForGlobalMetadata(GlobalVariable *G, GlobalVariable *Metadata,
767  StringRef InternalSuffix);
768  IRBuilder<> CreateAsanModuleDtor(Module &M);
769 
770  bool ShouldInstrumentGlobal(GlobalVariable *G);
771  bool ShouldUseMachOGlobalsSection() const;
772  StringRef getGlobalMetadataSection() const;
773  void poisonOneInitializer(Function &GlobalInit, GlobalValue *ModuleName);
774  void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
775  size_t MinRedzoneSizeForGlobal() const {
776  return RedzoneSizeForScale(Mapping.Scale);
777  }
778  int GetAsanVersion(const Module &M) const;
779 
780  GlobalsMetadata GlobalsMD;
781  bool CompileKernel;
782  bool Recover;
783  bool UseGlobalsGC;
784  bool UseCtorComdat;
785  Type *IntptrTy;
786  LLVMContext *C;
787  Triple TargetTriple;
788  ShadowMapping Mapping;
789  Function *AsanPoisonGlobals;
790  Function *AsanUnpoisonGlobals;
791  Function *AsanRegisterGlobals;
792  Function *AsanUnregisterGlobals;
793  Function *AsanRegisterImageGlobals;
794  Function *AsanUnregisterImageGlobals;
795  Function *AsanRegisterElfGlobals;
796  Function *AsanUnregisterElfGlobals;
797 
798  Function *AsanCtorFunction = nullptr;
799  Function *AsanDtorFunction = nullptr;
800 };
801 
802 // Stack poisoning does not play well with exception handling.
803 // When an exception is thrown, we essentially bypass the code
804 // that unpoisones the stack. This is why the run-time library has
805 // to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
806 // stack in the interceptor. This however does not work inside the
807 // actual function which catches the exception. Most likely because the
808 // compiler hoists the load of the shadow value somewhere too high.
809 // This causes asan to report a non-existing bug on 453.povray.
810 // It sounds like an LLVM bug.
811 struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
812  Function &F;
813  AddressSanitizer &ASan;
814  DIBuilder DIB;
815  LLVMContext *C;
816  Type *IntptrTy;
817  Type *IntptrPtrTy;
818  ShadowMapping Mapping;
819 
821  SmallVector<AllocaInst *, 16> StaticAllocasToMoveUp;
823  unsigned StackAlignment;
824 
825  Function *AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
826  *AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
827  Function *AsanSetShadowFunc[0x100] = {};
828  Function *AsanPoisonStackMemoryFunc, *AsanUnpoisonStackMemoryFunc;
829  Function *AsanAllocaPoisonFunc, *AsanAllocasUnpoisonFunc;
830 
831  // Stores a place and arguments of poisoning/unpoisoning call for alloca.
832  struct AllocaPoisonCall {
833  IntrinsicInst *InsBefore;
834  AllocaInst *AI;
835  uint64_t Size;
836  bool DoPoison;
837  };
838  SmallVector<AllocaPoisonCall, 8> DynamicAllocaPoisonCallVec;
839  SmallVector<AllocaPoisonCall, 8> StaticAllocaPoisonCallVec;
840 
841  SmallVector<AllocaInst *, 1> DynamicAllocaVec;
842  SmallVector<IntrinsicInst *, 1> StackRestoreVec;
843  AllocaInst *DynamicAllocaLayout = nullptr;
844  IntrinsicInst *LocalEscapeCall = nullptr;
845 
846  // Maps Value to an AllocaInst from which the Value is originated.
847  using AllocaForValueMapTy = DenseMap<Value *, AllocaInst *>;
848  AllocaForValueMapTy AllocaForValue;
849 
850  bool HasNonEmptyInlineAsm = false;
851  bool HasReturnsTwiceCall = false;
852  std::unique_ptr<CallInst> EmptyInlineAsm;
853 
854  FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
855  : F(F),
856  ASan(ASan),
857  DIB(*F.getParent(), /*AllowUnresolved*/ false),
858  C(ASan.C),
859  IntptrTy(ASan.IntptrTy),
860  IntptrPtrTy(PointerType::get(IntptrTy, 0)),
861  Mapping(ASan.Mapping),
862  StackAlignment(1 << Mapping.Scale),
863  EmptyInlineAsm(CallInst::Create(ASan.EmptyAsm)) {}
864 
865  bool runOnFunction() {
866  if (!ClStack) return false;
867 
868  if (ClRedzoneByvalArgs)
869  copyArgsPassedByValToAllocas();
870 
871  // Collect alloca, ret, lifetime instructions etc.
872  for (BasicBlock *BB : depth_first(&F.getEntryBlock())) visit(*BB);
873 
874  if (AllocaVec.empty() && DynamicAllocaVec.empty()) return false;
875 
876  initializeCallbacks(*F.getParent());
877 
878  processDynamicAllocas();
879  processStaticAllocas();
880 
881  if (ClDebugStack) {
882  LLVM_DEBUG(dbgs() << F);
883  }
884  return true;
885  }
886 
887  // Arguments marked with the "byval" attribute are implicitly copied without
888  // using an alloca instruction. To produce redzones for those arguments, we
889  // copy them a second time into memory allocated with an alloca instruction.
890  void copyArgsPassedByValToAllocas();
891 
892  // Finds all Alloca instructions and puts
893  // poisoned red zones around all of them.
894  // Then unpoison everything back before the function returns.
895  void processStaticAllocas();
896  void processDynamicAllocas();
897 
898  void createDynamicAllocasInitStorage();
899 
900  // ----------------------- Visitors.
901  /// Collect all Ret instructions.
902  void visitReturnInst(ReturnInst &RI) { RetVec.push_back(&RI); }
903 
904  /// Collect all Resume instructions.
905  void visitResumeInst(ResumeInst &RI) { RetVec.push_back(&RI); }
906 
907  /// Collect all CatchReturnInst instructions.
908  void visitCleanupReturnInst(CleanupReturnInst &CRI) { RetVec.push_back(&CRI); }
909 
910  void unpoisonDynamicAllocasBeforeInst(Instruction *InstBefore,
911  Value *SavedStack) {
912  IRBuilder<> IRB(InstBefore);
913  Value *DynamicAreaPtr = IRB.CreatePtrToInt(SavedStack, IntptrTy);
914  // When we insert _asan_allocas_unpoison before @llvm.stackrestore, we
915  // need to adjust extracted SP to compute the address of the most recent
916  // alloca. We have a special @llvm.get.dynamic.area.offset intrinsic for
917  // this purpose.
918  if (!isa<ReturnInst>(InstBefore)) {
919  Function *DynamicAreaOffsetFunc = Intrinsic::getDeclaration(
920  InstBefore->getModule(), Intrinsic::get_dynamic_area_offset,
921  {IntptrTy});
922 
923  Value *DynamicAreaOffset = IRB.CreateCall(DynamicAreaOffsetFunc, {});
924 
925  DynamicAreaPtr = IRB.CreateAdd(IRB.CreatePtrToInt(SavedStack, IntptrTy),
926  DynamicAreaOffset);
927  }
928 
929  IRB.CreateCall(AsanAllocasUnpoisonFunc,
930  {IRB.CreateLoad(DynamicAllocaLayout), DynamicAreaPtr});
931  }
932 
933  // Unpoison dynamic allocas redzones.
934  void unpoisonDynamicAllocas() {
935  for (auto &Ret : RetVec)
936  unpoisonDynamicAllocasBeforeInst(Ret, DynamicAllocaLayout);
937 
938  for (auto &StackRestoreInst : StackRestoreVec)
939  unpoisonDynamicAllocasBeforeInst(StackRestoreInst,
940  StackRestoreInst->getOperand(0));
941  }
942 
943  // Deploy and poison redzones around dynamic alloca call. To do this, we
944  // should replace this call with another one with changed parameters and
945  // replace all its uses with new address, so
946  // addr = alloca type, old_size, align
947  // is replaced by
948  // new_size = (old_size + additional_size) * sizeof(type)
949  // tmp = alloca i8, new_size, max(align, 32)
950  // addr = tmp + 32 (first 32 bytes are for the left redzone).
951  // Additional_size is added to make new memory allocation contain not only
952  // requested memory, but also left, partial and right redzones.
953  void handleDynamicAllocaCall(AllocaInst *AI);
954 
955  /// Collect Alloca instructions we want (and can) handle.
956  void visitAllocaInst(AllocaInst &AI) {
957  if (!ASan.isInterestingAlloca(AI)) {
958  if (AI.isStaticAlloca()) {
959  // Skip over allocas that are present *before* the first instrumented
960  // alloca, we don't want to move those around.
961  if (AllocaVec.empty())
962  return;
963 
964  StaticAllocasToMoveUp.push_back(&AI);
965  }
966  return;
967  }
968 
969  StackAlignment = std::max(StackAlignment, AI.getAlignment());
970  if (!AI.isStaticAlloca())
971  DynamicAllocaVec.push_back(&AI);
972  else
973  AllocaVec.push_back(&AI);
974  }
975 
976  /// Collect lifetime intrinsic calls to check for use-after-scope
977  /// errors.
978  void visitIntrinsicInst(IntrinsicInst &II) {
980  if (ID == Intrinsic::stackrestore) StackRestoreVec.push_back(&II);
981  if (ID == Intrinsic::localescape) LocalEscapeCall = &II;
982  if (!ASan.UseAfterScope)
983  return;
984  if (ID != Intrinsic::lifetime_start && ID != Intrinsic::lifetime_end)
985  return;
986  // Found lifetime intrinsic, add ASan instrumentation if necessary.
988  // If size argument is undefined, don't do anything.
989  if (Size->isMinusOne()) return;
990  // Check that size doesn't saturate uint64_t and can
991  // be stored in IntptrTy.
992  const uint64_t SizeValue = Size->getValue().getLimitedValue();
993  if (SizeValue == ~0ULL ||
994  !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
995  return;
996  // Find alloca instruction that corresponds to llvm.lifetime argument.
997  AllocaInst *AI = findAllocaForValue(II.getArgOperand(1));
998  if (!AI || !ASan.isInterestingAlloca(*AI))
999  return;
1000  bool DoPoison = (ID == Intrinsic::lifetime_end);
1001  AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
1002  if (AI->isStaticAlloca())
1003  StaticAllocaPoisonCallVec.push_back(APC);
1004  else if (ClInstrumentDynamicAllocas)
1005  DynamicAllocaPoisonCallVec.push_back(APC);
1006  }
1007 
1008  void visitCallSite(CallSite CS) {
1009  Instruction *I = CS.getInstruction();
1010  if (CallInst *CI = dyn_cast<CallInst>(I)) {
1011  HasNonEmptyInlineAsm |= CI->isInlineAsm() &&
1012  !CI->isIdenticalTo(EmptyInlineAsm.get()) &&
1013  I != ASan.LocalDynamicShadow;
1014  HasReturnsTwiceCall |= CI->canReturnTwice();
1015  }
1016  }
1017 
1018  // ---------------------- Helpers.
1019  void initializeCallbacks(Module &M);
1020 
1021  bool doesDominateAllExits(const Instruction *I) const {
1022  for (auto Ret : RetVec) {
1023  if (!ASan.getDominatorTree().dominates(I, Ret)) return false;
1024  }
1025  return true;
1026  }
1027 
1028  /// Finds alloca where the value comes from.
1029  AllocaInst *findAllocaForValue(Value *V);
1030 
1031  // Copies bytes from ShadowBytes into shadow memory for indexes where
1032  // ShadowMask is not zero. If ShadowMask[i] is zero, we assume that
1033  // ShadowBytes[i] is constantly zero and doesn't need to be overwritten.
1034  void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1035  IRBuilder<> &IRB, Value *ShadowBase);
1036  void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1037  size_t Begin, size_t End, IRBuilder<> &IRB,
1038  Value *ShadowBase);
1039  void copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
1040  ArrayRef<uint8_t> ShadowBytes, size_t Begin,
1041  size_t End, IRBuilder<> &IRB, Value *ShadowBase);
1042 
1043  void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
1044 
1045  Value *createAllocaForLayout(IRBuilder<> &IRB, const ASanStackFrameLayout &L,
1046  bool Dynamic);
1047  PHINode *createPHI(IRBuilder<> &IRB, Value *Cond, Value *ValueIfTrue,
1048  Instruction *ThenTerm, Value *ValueIfFalse);
1049 };
1050 
1051 class AddressSanitizerLegacyPass : public FunctionPass {
1052 public:
1053  static char ID;
1054 
1055  explicit AddressSanitizerLegacyPass(bool CompileKernel = false,
1056  bool Recover = false,
1057  bool UseAfterScope = false)
1058  : FunctionPass(ID), CompileKernel(CompileKernel), Recover(Recover),
1059  UseAfterScope(UseAfterScope) {
1061  }
1062 
1063  StringRef getPassName() const override {
1064  return "AddressSanitizerFunctionPass";
1065  }
1066 
1067  void getAnalysisUsage(AnalysisUsage &AU) const override {
1070  }
1071 
1072  bool runOnFunction(Function &F) override {
1073  DominatorTree *DTree =
1074  &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
1075  const TargetLibraryInfo *TLI =
1076  &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
1077  AddressSanitizer Sanitizer(*F.getParent(), DTree, CompileKernel, Recover,
1078  UseAfterScope);
1079  return Sanitizer.instrument(F, TLI);
1080  }
1081 
1082 private:
1083  bool CompileKernel;
1084  bool Recover;
1085  bool UseAfterScope;
1086 };
1087 
1088 class AddressSanitizerModuleLegacyPass : public ModulePass {
1089 public:
1090  static char ID;
1091 
1092  explicit AddressSanitizerModuleLegacyPass(bool CompileKernel = false,
1093  bool Recover = false,
1094  bool UseAfterScope = true)
1095  : ModulePass(ID), CompileKernel(CompileKernel), Recover(Recover),
1096  UseAfterScope(UseAfterScope) {}
1097 
1098  StringRef getPassName() const override { return "AddressSanitizerModule"; }
1099 
1100  bool runOnModule(Module &M) override {
1101  AddressSanitizerModule Sanitizer(CompileKernel, Recover, UseAfterScope);
1102  return Sanitizer.instrument(M);
1103  }
1104 
1105 private:
1106  bool CompileKernel;
1107  bool Recover;
1108  bool UseAfterScope;
1109 };
1110 
1111 } // end anonymous namespace
1112 
1113 AddressSanitizerPass::AddressSanitizerPass(bool CompileKernel, bool Recover,
1114  bool UseAfterScope)
1115  : CompileKernel(CompileKernel), Recover(Recover),
1116  UseAfterScope(UseAfterScope) {}
1117 
1122  AddressSanitizer Sanitizer(*F.getParent(), DT, CompileKernel, Recover,
1123  UseAfterScope);
1124  if (Sanitizer.instrument(F, TLI))
1125  return PreservedAnalyses::none();
1126  return PreservedAnalyses::all();
1127 }
1128 
1131  AddressSanitizerModule Sanitizer(CompileKernel, Recover, UseAfterScope);
1132  if (Sanitizer.instrument(M))
1133  return PreservedAnalyses::none();
1134  return PreservedAnalyses::all();
1135 }
1136 
1138 
1140  AddressSanitizerLegacyPass, "asan",
1141  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,
1142  false)
1146  AddressSanitizerLegacyPass, "asan",
1147  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,
1148  false)
1149 
1151  bool Recover,
1152  bool UseAfterScope) {
1153  assert(!CompileKernel || Recover);
1154  return new AddressSanitizerLegacyPass(CompileKernel, Recover, UseAfterScope);
1155 }
1156 
1158 
1160  AddressSanitizerModuleLegacyPass, "asan-module",
1161  "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
1162  "ModulePass",
1163  false, false)
1164 
1165 ModulePass *llvm::createAddressSanitizerModulePass(bool CompileKernel,
1166  bool Recover,
1167  bool UseGlobalsGC) {
1168  assert(!CompileKernel || Recover);
1169  return new AddressSanitizerModuleLegacyPass(CompileKernel, Recover,
1170  UseGlobalsGC);
1171 }
1172 
1173 static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
1174  size_t Res = countTrailingZeros(TypeSize / 8);
1176  return Res;
1177 }
1178 
1179 /// Create a global describing a source location.
1181  LocationMetadata MD) {
1182  Constant *LocData[] = {
1183  createPrivateGlobalForString(M, MD.Filename, true, kAsanGenPrefix),
1184  ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.LineNo),
1185  ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.ColumnNo),
1186  };
1187  auto LocStruct = ConstantStruct::getAnon(LocData);
1188  auto GV = new GlobalVariable(M, LocStruct->getType(), true,
1189  GlobalValue::PrivateLinkage, LocStruct,
1190  kAsanGenPrefix);
1192  return GV;
1193 }
1194 
1195 /// Check if \p G has been created by a trusted compiler pass.
1197  // Do not instrument @llvm.global_ctors, @llvm.used, etc.
1198  if (G->getName().startswith("llvm."))
1199  return true;
1200 
1201  // Do not instrument asan globals.
1202  if (G->getName().startswith(kAsanGenPrefix) ||
1203  G->getName().startswith(kSanCovGenPrefix) ||
1204  G->getName().startswith(kODRGenPrefix))
1205  return true;
1206 
1207  // Do not instrument gcov counter arrays.
1208  if (G->getName() == "__llvm_gcov_ctr")
1209  return true;
1210 
1211  return false;
1212 }
1213 
1214 Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
1215  // Shadow >> scale
1216  Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
1217  if (Mapping.Offset == 0) return Shadow;
1218  // (Shadow >> scale) | offset
1219  Value *ShadowBase;
1220  if (LocalDynamicShadow)
1221  ShadowBase = LocalDynamicShadow;
1222  else
1223  ShadowBase = ConstantInt::get(IntptrTy, Mapping.Offset);
1224  if (Mapping.OrShadowOffset)
1225  return IRB.CreateOr(Shadow, ShadowBase);
1226  else
1227  return IRB.CreateAdd(Shadow, ShadowBase);
1228 }
1229 
1230 // Instrument memset/memmove/memcpy
1231 void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
1232  IRBuilder<> IRB(MI);
1233  if (isa<MemTransferInst>(MI)) {
1234  IRB.CreateCall(
1235  isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
1236  {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1237  IRB.CreatePointerCast(MI->getOperand(1), IRB.getInt8PtrTy()),
1238  IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1239  } else if (isa<MemSetInst>(MI)) {
1240  IRB.CreateCall(
1241  AsanMemset,
1242  {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1243  IRB.CreateIntCast(MI->getOperand(1), IRB.getInt32Ty(), false),
1244  IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1245  }
1246  MI->eraseFromParent();
1247 }
1248 
1249 /// Check if we want (and can) handle this alloca.
1250 bool AddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
1251  auto PreviouslySeenAllocaInfo = ProcessedAllocas.find(&AI);
1252 
1253  if (PreviouslySeenAllocaInfo != ProcessedAllocas.end())
1254  return PreviouslySeenAllocaInfo->getSecond();
1255 
1256  bool IsInteresting =
1257  (AI.getAllocatedType()->isSized() &&
1258  // alloca() may be called with 0 size, ignore it.
1259  ((!AI.isStaticAlloca()) || getAllocaSizeInBytes(AI) > 0) &&
1260  // We are only interested in allocas not promotable to registers.
1261  // Promotable allocas are common under -O0.
1263  // inalloca allocas are not treated as static, and we don't want
1264  // dynamic alloca instrumentation for them as well.
1265  !AI.isUsedWithInAlloca() &&
1266  // swifterror allocas are register promoted by ISel
1267  !AI.isSwiftError());
1268 
1269  ProcessedAllocas[&AI] = IsInteresting;
1270  return IsInteresting;
1271 }
1272 
1273 Value *AddressSanitizer::isInterestingMemoryAccess(Instruction *I,
1274  bool *IsWrite,
1275  uint64_t *TypeSize,
1276  unsigned *Alignment,
1277  Value **MaybeMask) {
1278  // Skip memory accesses inserted by another instrumentation.
1279  if (I->getMetadata("nosanitize")) return nullptr;
1280 
1281  // Do not instrument the load fetching the dynamic shadow address.
1282  if (LocalDynamicShadow == I)
1283  return nullptr;
1284 
1285  Value *PtrOperand = nullptr;
1286  const DataLayout &DL = I->getModule()->getDataLayout();
1287  if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
1288  if (!ClInstrumentReads) return nullptr;
1289  *IsWrite = false;
1290  *TypeSize = DL.getTypeStoreSizeInBits(LI->getType());
1291  *Alignment = LI->getAlignment();
1292  PtrOperand = LI->getPointerOperand();
1293  } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
1294  if (!ClInstrumentWrites) return nullptr;
1295  *IsWrite = true;
1296  *TypeSize = DL.getTypeStoreSizeInBits(SI->getValueOperand()->getType());
1297  *Alignment = SI->getAlignment();
1298  PtrOperand = SI->getPointerOperand();
1299  } else if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
1300  if (!ClInstrumentAtomics) return nullptr;
1301  *IsWrite = true;
1302  *TypeSize = DL.getTypeStoreSizeInBits(RMW->getValOperand()->getType());
1303  *Alignment = 0;
1304  PtrOperand = RMW->getPointerOperand();
1305  } else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
1306  if (!ClInstrumentAtomics) return nullptr;
1307  *IsWrite = true;
1308  *TypeSize = DL.getTypeStoreSizeInBits(XCHG->getCompareOperand()->getType());
1309  *Alignment = 0;
1310  PtrOperand = XCHG->getPointerOperand();
1311  } else if (auto CI = dyn_cast<CallInst>(I)) {
1312  auto *F = dyn_cast<Function>(CI->getCalledValue());
1313  if (F && (F->getName().startswith("llvm.masked.load.") ||
1314  F->getName().startswith("llvm.masked.store."))) {
1315  unsigned OpOffset = 0;
1316  if (F->getName().startswith("llvm.masked.store.")) {
1317  if (!ClInstrumentWrites)
1318  return nullptr;
1319  // Masked store has an initial operand for the value.
1320  OpOffset = 1;
1321  *IsWrite = true;
1322  } else {
1323  if (!ClInstrumentReads)
1324  return nullptr;
1325  *IsWrite = false;
1326  }
1327 
1328  auto BasePtr = CI->getOperand(0 + OpOffset);
1329  auto Ty = cast<PointerType>(BasePtr->getType())->getElementType();
1330  *TypeSize = DL.getTypeStoreSizeInBits(Ty);
1331  if (auto AlignmentConstant =
1332  dyn_cast<ConstantInt>(CI->getOperand(1 + OpOffset)))
1333  *Alignment = (unsigned)AlignmentConstant->getZExtValue();
1334  else
1335  *Alignment = 1; // No alignment guarantees. We probably got Undef
1336  if (MaybeMask)
1337  *MaybeMask = CI->getOperand(2 + OpOffset);
1338  PtrOperand = BasePtr;
1339  }
1340  }
1341 
1342  if (PtrOperand) {
1343  // Do not instrument acesses from different address spaces; we cannot deal
1344  // with them.
1345  Type *PtrTy = cast<PointerType>(PtrOperand->getType()->getScalarType());
1346  if (PtrTy->getPointerAddressSpace() != 0)
1347  return nullptr;
1348 
1349  // Ignore swifterror addresses.
1350  // swifterror memory addresses are mem2reg promoted by instruction
1351  // selection. As such they cannot have regular uses like an instrumentation
1352  // function and it makes no sense to track them as memory.
1353  if (PtrOperand->isSwiftError())
1354  return nullptr;
1355  }
1356 
1357  // Treat memory accesses to promotable allocas as non-interesting since they
1358  // will not cause memory violations. This greatly speeds up the instrumented
1359  // executable at -O0.
1361  if (auto AI = dyn_cast_or_null<AllocaInst>(PtrOperand))
1362  return isInterestingAlloca(*AI) ? AI : nullptr;
1363 
1364  return PtrOperand;
1365 }
1366 
1367 static bool isPointerOperand(Value *V) {
1368  return V->getType()->isPointerTy() || isa<PtrToIntInst>(V);
1369 }
1370 
1371 // This is a rough heuristic; it may cause both false positives and
1372 // false negatives. The proper implementation requires cooperation with
1373 // the frontend.
1375  if (ICmpInst *Cmp = dyn_cast<ICmpInst>(I)) {
1376  if (!Cmp->isRelational()) return false;
1377  } else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) {
1378  if (BO->getOpcode() != Instruction::Sub) return false;
1379  } else {
1380  return false;
1381  }
1382  return isPointerOperand(I->getOperand(0)) &&
1384 }
1385 
1386 bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
1387  // If a global variable does not have dynamic initialization we don't
1388  // have to instrument it. However, if a global does not have initializer
1389  // at all, we assume it has dynamic initializer (in other TU).
1390  return G->hasInitializer() && !GlobalsMD.get(G).IsDynInit;
1391 }
1392 
1393 void AddressSanitizer::instrumentPointerComparisonOrSubtraction(
1394  Instruction *I) {
1395  IRBuilder<> IRB(I);
1396  Function *F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
1397  Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
1398  for (Value *&i : Param) {
1399  if (i->getType()->isPointerTy())
1400  i = IRB.CreatePointerCast(i, IntptrTy);
1401  }
1402  IRB.CreateCall(F, Param);
1403 }
1404 
1405 static void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I,
1406  Instruction *InsertBefore, Value *Addr,
1407  unsigned Alignment, unsigned Granularity,
1408  uint32_t TypeSize, bool IsWrite,
1409  Value *SizeArgument, bool UseCalls,
1410  uint32_t Exp) {
1411  // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check
1412  // if the data is properly aligned.
1413  if ((TypeSize == 8 || TypeSize == 16 || TypeSize == 32 || TypeSize == 64 ||
1414  TypeSize == 128) &&
1415  (Alignment >= Granularity || Alignment == 0 || Alignment >= TypeSize / 8))
1416  return Pass->instrumentAddress(I, InsertBefore, Addr, TypeSize, IsWrite,
1417  nullptr, UseCalls, Exp);
1418  Pass->instrumentUnusualSizeOrAlignment(I, InsertBefore, Addr, TypeSize,
1419  IsWrite, nullptr, UseCalls, Exp);
1420 }
1421 
1422 static void instrumentMaskedLoadOrStore(AddressSanitizer *Pass,
1423  const DataLayout &DL, Type *IntptrTy,
1424  Value *Mask, Instruction *I,
1425  Value *Addr, unsigned Alignment,
1426  unsigned Granularity, uint32_t TypeSize,
1427  bool IsWrite, Value *SizeArgument,
1428  bool UseCalls, uint32_t Exp) {
1429  auto *VTy = cast<PointerType>(Addr->getType())->getElementType();
1430  uint64_t ElemTypeSize = DL.getTypeStoreSizeInBits(VTy->getScalarType());
1431  unsigned Num = VTy->getVectorNumElements();
1432  auto Zero = ConstantInt::get(IntptrTy, 0);
1433  for (unsigned Idx = 0; Idx < Num; ++Idx) {
1434  Value *InstrumentedAddress = nullptr;
1435  Instruction *InsertBefore = I;
1436  if (auto *Vector = dyn_cast<ConstantVector>(Mask)) {
1437  // dyn_cast as we might get UndefValue
1438  if (auto *Masked = dyn_cast<ConstantInt>(Vector->getOperand(Idx))) {
1439  if (Masked->isZero())
1440  // Mask is constant false, so no instrumentation needed.
1441  continue;
1442  // If we have a true or undef value, fall through to doInstrumentAddress
1443  // with InsertBefore == I
1444  }
1445  } else {
1446  IRBuilder<> IRB(I);
1447  Value *MaskElem = IRB.CreateExtractElement(Mask, Idx);
1448  Instruction *ThenTerm = SplitBlockAndInsertIfThen(MaskElem, I, false);
1449  InsertBefore = ThenTerm;
1450  }
1451 
1452  IRBuilder<> IRB(InsertBefore);
1453  InstrumentedAddress =
1454  IRB.CreateGEP(Addr, {Zero, ConstantInt::get(IntptrTy, Idx)});
1455  doInstrumentAddress(Pass, I, InsertBefore, InstrumentedAddress, Alignment,
1456  Granularity, ElemTypeSize, IsWrite, SizeArgument,
1457  UseCalls, Exp);
1458  }
1459 }
1460 
1461 void AddressSanitizer::instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
1462  Instruction *I, bool UseCalls,
1463  const DataLayout &DL) {
1464  bool IsWrite = false;
1465  unsigned Alignment = 0;
1466  uint64_t TypeSize = 0;
1467  Value *MaybeMask = nullptr;
1468  Value *Addr =
1469  isInterestingMemoryAccess(I, &IsWrite, &TypeSize, &Alignment, &MaybeMask);
1470  assert(Addr);
1471 
1472  // Optimization experiments.
1473  // The experiments can be used to evaluate potential optimizations that remove
1474  // instrumentation (assess false negatives). Instead of completely removing
1475  // some instrumentation, you set Exp to a non-zero value (mask of optimization
1476  // experiments that want to remove instrumentation of this instruction).
1477  // If Exp is non-zero, this pass will emit special calls into runtime
1478  // (e.g. __asan_report_exp_load1 instead of __asan_report_load1). These calls
1479  // make runtime terminate the program in a special way (with a different
1480  // exit status). Then you run the new compiler on a buggy corpus, collect
1481  // the special terminations (ideally, you don't see them at all -- no false
1482  // negatives) and make the decision on the optimization.
1484 
1485  if (ClOpt && ClOptGlobals) {
1486  // If initialization order checking is disabled, a simple access to a
1487  // dynamically initialized global is always valid.
1489  if (G && (!ClInitializers || GlobalIsLinkerInitialized(G)) &&
1490  isSafeAccess(ObjSizeVis, Addr, TypeSize)) {
1491  NumOptimizedAccessesToGlobalVar++;
1492  return;
1493  }
1494  }
1495 
1496  if (ClOpt && ClOptStack) {
1497  // A direct inbounds access to a stack variable is always valid.
1498  if (isa<AllocaInst>(GetUnderlyingObject(Addr, DL)) &&
1499  isSafeAccess(ObjSizeVis, Addr, TypeSize)) {
1500  NumOptimizedAccessesToStackVar++;
1501  return;
1502  }
1503  }
1504 
1505  if (IsWrite)
1506  NumInstrumentedWrites++;
1507  else
1508  NumInstrumentedReads++;
1509 
1510  unsigned Granularity = 1 << Mapping.Scale;
1511  if (MaybeMask) {
1512  instrumentMaskedLoadOrStore(this, DL, IntptrTy, MaybeMask, I, Addr,
1513  Alignment, Granularity, TypeSize, IsWrite,
1514  nullptr, UseCalls, Exp);
1515  } else {
1516  doInstrumentAddress(this, I, I, Addr, Alignment, Granularity, TypeSize,
1517  IsWrite, nullptr, UseCalls, Exp);
1518  }
1519 }
1520 
1521 Instruction *AddressSanitizer::generateCrashCode(Instruction *InsertBefore,
1522  Value *Addr, bool IsWrite,
1523  size_t AccessSizeIndex,
1524  Value *SizeArgument,
1525  uint32_t Exp) {
1526  IRBuilder<> IRB(InsertBefore);
1527  Value *ExpVal = Exp == 0 ? nullptr : ConstantInt::get(IRB.getInt32Ty(), Exp);
1528  CallInst *Call = nullptr;
1529  if (SizeArgument) {
1530  if (Exp == 0)
1531  Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][0],
1532  {Addr, SizeArgument});
1533  else
1534  Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][1],
1535  {Addr, SizeArgument, ExpVal});
1536  } else {
1537  if (Exp == 0)
1538  Call =
1539  IRB.CreateCall(AsanErrorCallback[IsWrite][0][AccessSizeIndex], Addr);
1540  else
1541  Call = IRB.CreateCall(AsanErrorCallback[IsWrite][1][AccessSizeIndex],
1542  {Addr, ExpVal});
1543  }
1544 
1545  // We don't do Call->setDoesNotReturn() because the BB already has
1546  // UnreachableInst at the end.
1547  // This EmptyAsm is required to avoid callback merge.
1548  IRB.CreateCall(EmptyAsm, {});
1549  return Call;
1550 }
1551 
1552 Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
1553  Value *ShadowValue,
1554  uint32_t TypeSize) {
1555  size_t Granularity = static_cast<size_t>(1) << Mapping.Scale;
1556  // Addr & (Granularity - 1)
1557  Value *LastAccessedByte =
1558  IRB.CreateAnd(AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
1559  // (Addr & (Granularity - 1)) + size - 1
1560  if (TypeSize / 8 > 1)
1561  LastAccessedByte = IRB.CreateAdd(
1562  LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1));
1563  // (uint8_t) ((Addr & (Granularity-1)) + size - 1)
1564  LastAccessedByte =
1565  IRB.CreateIntCast(LastAccessedByte, ShadowValue->getType(), false);
1566  // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
1567  return IRB.CreateICmpSGE(LastAccessedByte, ShadowValue);
1568 }
1569 
1570 void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
1571  Instruction *InsertBefore, Value *Addr,
1572  uint32_t TypeSize, bool IsWrite,
1573  Value *SizeArgument, bool UseCalls,
1574  uint32_t Exp) {
1575  bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
1576 
1577  IRBuilder<> IRB(InsertBefore);
1578  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1579  size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
1580 
1581  if (UseCalls) {
1582  if (Exp == 0)
1583  IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][0][AccessSizeIndex],
1584  AddrLong);
1585  else
1586  IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][1][AccessSizeIndex],
1587  {AddrLong, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1588  return;
1589  }
1590 
1591  if (IsMyriad) {
1592  // Strip the cache bit and do range check.
1593  // AddrLong &= ~kMyriadCacheBitMask32
1594  AddrLong = IRB.CreateAnd(AddrLong, ~kMyriadCacheBitMask32);
1595  // Tag = AddrLong >> kMyriadTagShift
1596  Value *Tag = IRB.CreateLShr(AddrLong, kMyriadTagShift);
1597  // Tag == kMyriadDDRTag
1598  Value *TagCheck =
1599  IRB.CreateICmpEQ(Tag, ConstantInt::get(IntptrTy, kMyriadDDRTag));
1600 
1601  Instruction *TagCheckTerm =
1602  SplitBlockAndInsertIfThen(TagCheck, InsertBefore, false,
1603  MDBuilder(*C).createBranchWeights(1, 100000));
1604  assert(cast<BranchInst>(TagCheckTerm)->isUnconditional());
1605  IRB.SetInsertPoint(TagCheckTerm);
1606  InsertBefore = TagCheckTerm;
1607  }
1608 
1609  Type *ShadowTy =
1610  IntegerType::get(*C, std::max(8U, TypeSize >> Mapping.Scale));
1611  Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
1612  Value *ShadowPtr = memToShadow(AddrLong, IRB);
1613  Value *CmpVal = Constant::getNullValue(ShadowTy);
1614  Value *ShadowValue =
1615  IRB.CreateLoad(IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));
1616 
1617  Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
1618  size_t Granularity = 1ULL << Mapping.Scale;
1619  Instruction *CrashTerm = nullptr;
1620 
1621  if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
1622  // We use branch weights for the slow path check, to indicate that the slow
1623  // path is rarely taken. This seems to be the case for SPEC benchmarks.
1625  Cmp, InsertBefore, false, MDBuilder(*C).createBranchWeights(1, 100000));
1626  assert(cast<BranchInst>(CheckTerm)->isUnconditional());
1627  BasicBlock *NextBB = CheckTerm->getSuccessor(0);
1628  IRB.SetInsertPoint(CheckTerm);
1629  Value *Cmp2 = createSlowPathCmp(IRB, AddrLong, ShadowValue, TypeSize);
1630  if (Recover) {
1631  CrashTerm = SplitBlockAndInsertIfThen(Cmp2, CheckTerm, false);
1632  } else {
1633  BasicBlock *CrashBlock =
1634  BasicBlock::Create(*C, "", NextBB->getParent(), NextBB);
1635  CrashTerm = new UnreachableInst(*C, CrashBlock);
1636  BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
1637  ReplaceInstWithInst(CheckTerm, NewTerm);
1638  }
1639  } else {
1640  CrashTerm = SplitBlockAndInsertIfThen(Cmp, InsertBefore, !Recover);
1641  }
1642 
1643  Instruction *Crash = generateCrashCode(CrashTerm, AddrLong, IsWrite,
1644  AccessSizeIndex, SizeArgument, Exp);
1645  Crash->setDebugLoc(OrigIns->getDebugLoc());
1646 }
1647 
1648 // Instrument unusual size or unusual alignment.
1649 // We can not do it with a single check, so we do 1-byte check for the first
1650 // and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
1651 // to report the actual access size.
1652 void AddressSanitizer::instrumentUnusualSizeOrAlignment(
1653  Instruction *I, Instruction *InsertBefore, Value *Addr, uint32_t TypeSize,
1654  bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp) {
1655  IRBuilder<> IRB(InsertBefore);
1656  Value *Size = ConstantInt::get(IntptrTy, TypeSize / 8);
1657  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1658  if (UseCalls) {
1659  if (Exp == 0)
1660  IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][0],
1661  {AddrLong, Size});
1662  else
1663  IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][1],
1664  {AddrLong, Size, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1665  } else {
1666  Value *LastByte = IRB.CreateIntToPtr(
1667  IRB.CreateAdd(AddrLong, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
1668  Addr->getType());
1669  instrumentAddress(I, InsertBefore, Addr, 8, IsWrite, Size, false, Exp);
1670  instrumentAddress(I, InsertBefore, LastByte, 8, IsWrite, Size, false, Exp);
1671  }
1672 }
1673 
1674 void AddressSanitizerModule::poisonOneInitializer(Function &GlobalInit,
1675  GlobalValue *ModuleName) {
1676  // Set up the arguments to our poison/unpoison functions.
1677  IRBuilder<> IRB(&GlobalInit.front(),
1678  GlobalInit.front().getFirstInsertionPt());
1679 
1680  // Add a call to poison all external globals before the given function starts.
1681  Value *ModuleNameAddr = ConstantExpr::getPointerCast(ModuleName, IntptrTy);
1682  IRB.CreateCall(AsanPoisonGlobals, ModuleNameAddr);
1683 
1684  // Add calls to unpoison all globals before each return instruction.
1685  for (auto &BB : GlobalInit.getBasicBlockList())
1686  if (ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator()))
1687  CallInst::Create(AsanUnpoisonGlobals, "", RI);
1688 }
1689 
1690 void AddressSanitizerModule::createInitializerPoisonCalls(
1691  Module &M, GlobalValue *ModuleName) {
1692  GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
1693  if (!GV)
1694  return;
1695 
1697  if (!CA)
1698  return;
1699 
1700  for (Use &OP : CA->operands()) {
1701  if (isa<ConstantAggregateZero>(OP)) continue;
1702  ConstantStruct *CS = cast<ConstantStruct>(OP);
1703 
1704  // Must have a function or null ptr.
1705  if (Function *F = dyn_cast<Function>(CS->getOperand(1))) {
1706  if (F->getName() == kAsanModuleCtorName) continue;
1707  ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1708  // Don't instrument CTORs that will run before asan.module_ctor.
1709  if (Priority->getLimitedValue() <= kAsanCtorAndDtorPriority) continue;
1710  poisonOneInitializer(*F, ModuleName);
1711  }
1712  }
1713 }
1714 
1715 bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
1716  Type *Ty = G->getValueType();
1717  LLVM_DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
1718 
1719  if (GlobalsMD.get(G).IsBlacklisted) return false;
1720  if (!Ty->isSized()) return false;
1721  if (!G->hasInitializer()) return false;
1722  if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
1723  // Two problems with thread-locals:
1724  // - The address of the main thread's copy can't be computed at link-time.
1725  // - Need to poison all copies, not just the main thread's one.
1726  if (G->isThreadLocal()) return false;
1727  // For now, just ignore this Global if the alignment is large.
1728  if (G->getAlignment() > MinRedzoneSizeForGlobal()) return false;
1729 
1730  // For non-COFF targets, only instrument globals known to be defined by this
1731  // TU.
1732  // FIXME: We can instrument comdat globals on ELF if we are using the
1733  // GC-friendly metadata scheme.
1734  if (!TargetTriple.isOSBinFormatCOFF()) {
1735  if (!G->hasExactDefinition() || G->hasComdat())
1736  return false;
1737  } else {
1738  // On COFF, don't instrument non-ODR linkages.
1739  if (G->isInterposable())
1740  return false;
1741  }
1742 
1743  // If a comdat is present, it must have a selection kind that implies ODR
1744  // semantics: no duplicates, any, or exact match.
1745  if (Comdat *C = G->getComdat()) {
1746  switch (C->getSelectionKind()) {
1747  case Comdat::Any:
1748  case Comdat::ExactMatch:
1749  case Comdat::NoDuplicates:
1750  break;
1751  case Comdat::Largest:
1752  case Comdat::SameSize:
1753  return false;
1754  }
1755  }
1756 
1757  if (G->hasSection()) {
1758  StringRef Section = G->getSection();
1759 
1760  // Globals from llvm.metadata aren't emitted, do not instrument them.
1761  if (Section == "llvm.metadata") return false;
1762  // Do not instrument globals from special LLVM sections.
1763  if (Section.find("__llvm") != StringRef::npos || Section.find("__LLVM") != StringRef::npos) return false;
1764 
1765  // Do not instrument function pointers to initialization and termination
1766  // routines: dynamic linker will not properly handle redzones.
1767  if (Section.startswith(".preinit_array") ||
1768  Section.startswith(".init_array") ||
1769  Section.startswith(".fini_array")) {
1770  return false;
1771  }
1772 
1773  // On COFF, if the section name contains '$', it is highly likely that the
1774  // user is using section sorting to create an array of globals similar to
1775  // the way initialization callbacks are registered in .init_array and
1776  // .CRT$XCU. The ATL also registers things in .ATL$__[azm]. Adding redzones
1777  // to such globals is counterproductive, because the intent is that they
1778  // will form an array, and out-of-bounds accesses are expected.
1779  // See https://github.com/google/sanitizers/issues/305
1780  // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
1781  if (TargetTriple.isOSBinFormatCOFF() && Section.contains('$')) {
1782  LLVM_DEBUG(dbgs() << "Ignoring global in sorted section (contains '$'): "
1783  << *G << "\n");
1784  return false;
1785  }
1786 
1787  if (TargetTriple.isOSBinFormatMachO()) {
1788  StringRef ParsedSegment, ParsedSection;
1789  unsigned TAA = 0, StubSize = 0;
1790  bool TAAParsed;
1791  std::string ErrorCode = MCSectionMachO::ParseSectionSpecifier(
1792  Section, ParsedSegment, ParsedSection, TAA, TAAParsed, StubSize);
1793  assert(ErrorCode.empty() && "Invalid section specifier.");
1794 
1795  // Ignore the globals from the __OBJC section. The ObjC runtime assumes
1796  // those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
1797  // them.
1798  if (ParsedSegment == "__OBJC" ||
1799  (ParsedSegment == "__DATA" && ParsedSection.startswith("__objc_"))) {
1800  LLVM_DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G << "\n");
1801  return false;
1802  }
1803  // See https://github.com/google/sanitizers/issues/32
1804  // Constant CFString instances are compiled in the following way:
1805  // -- the string buffer is emitted into
1806  // __TEXT,__cstring,cstring_literals
1807  // -- the constant NSConstantString structure referencing that buffer
1808  // is placed into __DATA,__cfstring
1809  // Therefore there's no point in placing redzones into __DATA,__cfstring.
1810  // Moreover, it causes the linker to crash on OS X 10.7
1811  if (ParsedSegment == "__DATA" && ParsedSection == "__cfstring") {
1812  LLVM_DEBUG(dbgs() << "Ignoring CFString: " << *G << "\n");
1813  return false;
1814  }
1815  // The linker merges the contents of cstring_literals and removes the
1816  // trailing zeroes.
1817  if (ParsedSegment == "__TEXT" && (TAA & MachO::S_CSTRING_LITERALS)) {
1818  LLVM_DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n");
1819  return false;
1820  }
1821  }
1822  }
1823 
1824  return true;
1825 }
1826 
1827 // On Mach-O platforms, we emit global metadata in a separate section of the
1828 // binary in order to allow the linker to properly dead strip. This is only
1829 // supported on recent versions of ld64.
1830 bool AddressSanitizerModule::ShouldUseMachOGlobalsSection() const {
1831  if (!TargetTriple.isOSBinFormatMachO())
1832  return false;
1833 
1834  if (TargetTriple.isMacOSX() && !TargetTriple.isMacOSXVersionLT(10, 11))
1835  return true;
1836  if (TargetTriple.isiOS() /* or tvOS */ && !TargetTriple.isOSVersionLT(9))
1837  return true;
1838  if (TargetTriple.isWatchOS() && !TargetTriple.isOSVersionLT(2))
1839  return true;
1840 
1841  return false;
1842 }
1843 
1844 StringRef AddressSanitizerModule::getGlobalMetadataSection() const {
1845  switch (TargetTriple.getObjectFormat()) {
1846  case Triple::COFF: return ".ASAN$GL";
1847  case Triple::ELF: return "asan_globals";
1848  case Triple::MachO: return "__DATA,__asan_globals,regular";
1849  default: break;
1850  }
1851  llvm_unreachable("unsupported object format");
1852 }
1853 
1854 void AddressSanitizerModule::initializeCallbacks(Module &M) {
1855  IRBuilder<> IRB(*C);
1856 
1857  // Declare our poisoning and unpoisoning functions.
1859  kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy));
1860  AsanPoisonGlobals->setLinkage(Function::ExternalLinkage);
1861  AsanUnpoisonGlobals = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
1862  kAsanUnpoisonGlobalsName, IRB.getVoidTy()));
1863  AsanUnpoisonGlobals->setLinkage(Function::ExternalLinkage);
1864 
1865  // Declare functions that register/unregister globals.
1866  AsanRegisterGlobals = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
1867  kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy));
1868  AsanRegisterGlobals->setLinkage(Function::ExternalLinkage);
1869  AsanUnregisterGlobals = checkSanitizerInterfaceFunction(
1870  M.getOrInsertFunction(kAsanUnregisterGlobalsName, IRB.getVoidTy(),
1871  IntptrTy, IntptrTy));
1872  AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
1873 
1874  // Declare the functions that find globals in a shared object and then invoke
1875  // the (un)register function on them.
1876  AsanRegisterImageGlobals =
1878  kAsanRegisterImageGlobalsName, IRB.getVoidTy(), IntptrTy));
1879  AsanRegisterImageGlobals->setLinkage(Function::ExternalLinkage);
1880 
1881  AsanUnregisterImageGlobals =
1883  kAsanUnregisterImageGlobalsName, IRB.getVoidTy(), IntptrTy));
1884  AsanUnregisterImageGlobals->setLinkage(Function::ExternalLinkage);
1885 
1886  AsanRegisterElfGlobals = checkSanitizerInterfaceFunction(
1887  M.getOrInsertFunction(kAsanRegisterElfGlobalsName, IRB.getVoidTy(),
1888  IntptrTy, IntptrTy, IntptrTy));
1889  AsanRegisterElfGlobals->setLinkage(Function::ExternalLinkage);
1890 
1891  AsanUnregisterElfGlobals = checkSanitizerInterfaceFunction(
1892  M.getOrInsertFunction(kAsanUnregisterElfGlobalsName, IRB.getVoidTy(),
1893  IntptrTy, IntptrTy, IntptrTy));
1894  AsanUnregisterElfGlobals->setLinkage(Function::ExternalLinkage);
1895 }
1896 
1897 // Put the metadata and the instrumented global in the same group. This ensures
1898 // that the metadata is discarded if the instrumented global is discarded.
1899 void AddressSanitizerModule::SetComdatForGlobalMetadata(
1900  GlobalVariable *G, GlobalVariable *Metadata, StringRef InternalSuffix) {
1901  Module &M = *G->getParent();
1902  Comdat *C = G->getComdat();
1903  if (!C) {
1904  if (!G->hasName()) {
1905  // If G is unnamed, it must be internal. Give it an artificial name
1906  // so we can put it in a comdat.
1907  assert(G->hasLocalLinkage());
1908  G->setName(Twine(kAsanGenPrefix) + "_anon_global");
1909  }
1910 
1911  if (!InternalSuffix.empty() && G->hasLocalLinkage()) {
1912  std::string Name = G->getName();
1913  Name += InternalSuffix;
1914  C = M.getOrInsertComdat(Name);
1915  } else {
1916  C = M.getOrInsertComdat(G->getName());
1917  }
1918 
1919  // Make this IMAGE_COMDAT_SELECT_NODUPLICATES on COFF. Also upgrade private
1920  // linkage to internal linkage so that a symbol table entry is emitted. This
1921  // is necessary in order to create the comdat group.
1922  if (TargetTriple.isOSBinFormatCOFF()) {
1924  if (G->hasPrivateLinkage())
1926  }
1927  G->setComdat(C);
1928  }
1929 
1930  assert(G->hasComdat());
1931  Metadata->setComdat(G->getComdat());
1932 }
1933 
1934 // Create a separate metadata global and put it in the appropriate ASan
1935 // global registration section.
1937 AddressSanitizerModule::CreateMetadataGlobal(Module &M, Constant *Initializer,
1938  StringRef OriginalName) {
1939  auto Linkage = TargetTriple.isOSBinFormatMachO()
1942  GlobalVariable *Metadata = new GlobalVariable(
1943  M, Initializer->getType(), false, Linkage, Initializer,
1944  Twine("__asan_global_") + GlobalValue::dropLLVMManglingEscape(OriginalName));
1945  Metadata->setSection(getGlobalMetadataSection());
1946  return Metadata;
1947 }
1948 
1949 IRBuilder<> AddressSanitizerModule::CreateAsanModuleDtor(Module &M) {
1950  AsanDtorFunction =
1952  GlobalValue::InternalLinkage, kAsanModuleDtorName, &M);
1953  BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
1954 
1955  return IRBuilder<>(ReturnInst::Create(*C, AsanDtorBB));
1956 }
1957 
1958 void AddressSanitizerModule::InstrumentGlobalsCOFF(
1959  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
1960  ArrayRef<Constant *> MetadataInitializers) {
1961  assert(ExtendedGlobals.size() == MetadataInitializers.size());
1962  auto &DL = M.getDataLayout();
1963 
1964  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
1965  Constant *Initializer = MetadataInitializers[i];
1966  GlobalVariable *G = ExtendedGlobals[i];
1967  GlobalVariable *Metadata =
1968  CreateMetadataGlobal(M, Initializer, G->getName());
1969 
1970  // The MSVC linker always inserts padding when linking incrementally. We
1971  // cope with that by aligning each struct to its size, which must be a power
1972  // of two.
1973  unsigned SizeOfGlobalStruct = DL.getTypeAllocSize(Initializer->getType());
1974  assert(isPowerOf2_32(SizeOfGlobalStruct) &&
1975  "global metadata will not be padded appropriately");
1976  Metadata->setAlignment(SizeOfGlobalStruct);
1977 
1978  SetComdatForGlobalMetadata(G, Metadata, "");
1979  }
1980 }
1981 
1982 void AddressSanitizerModule::InstrumentGlobalsELF(
1983  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
1984  ArrayRef<Constant *> MetadataInitializers,
1985  const std::string &UniqueModuleId) {
1986  assert(ExtendedGlobals.size() == MetadataInitializers.size());
1987 
1988  SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
1989  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
1990  GlobalVariable *G = ExtendedGlobals[i];
1991  GlobalVariable *Metadata =
1992  CreateMetadataGlobal(M, MetadataInitializers[i], G->getName());
1994  Metadata->setMetadata(LLVMContext::MD_associated, MD);
1995  MetadataGlobals[i] = Metadata;
1996 
1997  SetComdatForGlobalMetadata(G, Metadata, UniqueModuleId);
1998  }
1999 
2000  // Update llvm.compiler.used, adding the new metadata globals. This is
2001  // needed so that during LTO these variables stay alive.
2002  if (!MetadataGlobals.empty())
2003  appendToCompilerUsed(M, MetadataGlobals);
2004 
2005  // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2006  // to look up the loaded image that contains it. Second, we can store in it
2007  // whether registration has already occurred, to prevent duplicate
2008  // registration.
2009  //
2010  // Common linkage ensures that there is only one global per shared library.
2011  GlobalVariable *RegisteredFlag = new GlobalVariable(
2012  M, IntptrTy, false, GlobalVariable::CommonLinkage,
2013  ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
2015 
2016  // Create start and stop symbols.
2017  GlobalVariable *StartELFMetadata = new GlobalVariable(
2018  M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2019  "__start_" + getGlobalMetadataSection());
2021  GlobalVariable *StopELFMetadata = new GlobalVariable(
2022  M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2023  "__stop_" + getGlobalMetadataSection());
2025 
2026  // Create a call to register the globals with the runtime.
2027  IRB.CreateCall(AsanRegisterElfGlobals,
2028  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2029  IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2030  IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2031 
2032  // We also need to unregister globals at the end, e.g., when a shared library
2033  // gets closed.
2034  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2035  IRB_Dtor.CreateCall(AsanUnregisterElfGlobals,
2036  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2037  IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2038  IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2039 }
2040 
2041 void AddressSanitizerModule::InstrumentGlobalsMachO(
2042  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2043  ArrayRef<Constant *> MetadataInitializers) {
2044  assert(ExtendedGlobals.size() == MetadataInitializers.size());
2045 
2046  // On recent Mach-O platforms, use a structure which binds the liveness of
2047  // the global variable to the metadata struct. Keep the list of "Liveness" GV
2048  // created to be added to llvm.compiler.used
2049  StructType *LivenessTy = StructType::get(IntptrTy, IntptrTy);
2050  SmallVector<GlobalValue *, 16> LivenessGlobals(ExtendedGlobals.size());
2051 
2052  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2053  Constant *Initializer = MetadataInitializers[i];
2054  GlobalVariable *G = ExtendedGlobals[i];
2055  GlobalVariable *Metadata =
2056  CreateMetadataGlobal(M, Initializer, G->getName());
2057 
2058  // On recent Mach-O platforms, we emit the global metadata in a way that
2059  // allows the linker to properly strip dead globals.
2060  auto LivenessBinder =
2061  ConstantStruct::get(LivenessTy, Initializer->getAggregateElement(0u),
2062  ConstantExpr::getPointerCast(Metadata, IntptrTy));
2063  GlobalVariable *Liveness = new GlobalVariable(
2064  M, LivenessTy, false, GlobalVariable::InternalLinkage, LivenessBinder,
2065  Twine("__asan_binder_") + G->getName());
2066  Liveness->setSection("__DATA,__asan_liveness,regular,live_support");
2067  LivenessGlobals[i] = Liveness;
2068  }
2069 
2070  // Update llvm.compiler.used, adding the new liveness globals. This is
2071  // needed so that during LTO these variables stay alive. The alternative
2072  // would be to have the linker handling the LTO symbols, but libLTO
2073  // current API does not expose access to the section for each symbol.
2074  if (!LivenessGlobals.empty())
2075  appendToCompilerUsed(M, LivenessGlobals);
2076 
2077  // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2078  // to look up the loaded image that contains it. Second, we can store in it
2079  // whether registration has already occurred, to prevent duplicate
2080  // registration.
2081  //
2082  // common linkage ensures that there is only one global per shared library.
2083  GlobalVariable *RegisteredFlag = new GlobalVariable(
2084  M, IntptrTy, false, GlobalVariable::CommonLinkage,
2085  ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
2087 
2088  IRB.CreateCall(AsanRegisterImageGlobals,
2089  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2090 
2091  // We also need to unregister globals at the end, e.g., when a shared library
2092  // gets closed.
2093  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2094  IRB_Dtor.CreateCall(AsanUnregisterImageGlobals,
2095  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2096 }
2097 
2098 void AddressSanitizerModule::InstrumentGlobalsWithMetadataArray(
2099  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2100  ArrayRef<Constant *> MetadataInitializers) {
2101  assert(ExtendedGlobals.size() == MetadataInitializers.size());
2102  unsigned N = ExtendedGlobals.size();
2103  assert(N > 0);
2104 
2105  // On platforms that don't have a custom metadata section, we emit an array
2106  // of global metadata structures.
2107  ArrayType *ArrayOfGlobalStructTy =
2108  ArrayType::get(MetadataInitializers[0]->getType(), N);
2109  auto AllGlobals = new GlobalVariable(
2110  M, ArrayOfGlobalStructTy, false, GlobalVariable::InternalLinkage,
2111  ConstantArray::get(ArrayOfGlobalStructTy, MetadataInitializers), "");
2112  if (Mapping.Scale > 3)
2113  AllGlobals->setAlignment(1ULL << Mapping.Scale);
2114 
2115  IRB.CreateCall(AsanRegisterGlobals,
2116  {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2117  ConstantInt::get(IntptrTy, N)});
2118 
2119  // We also need to unregister globals at the end, e.g., when a shared library
2120  // gets closed.
2121  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2122  IRB_Dtor.CreateCall(AsanUnregisterGlobals,
2123  {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2124  ConstantInt::get(IntptrTy, N)});
2125 }
2126 
2127 // This function replaces all global variables with new variables that have
2128 // trailing redzones. It also creates a function that poisons
2129 // redzones and inserts this function into llvm.global_ctors.
2130 // Sets *CtorComdat to true if the global registration code emitted into the
2131 // asan constructor is comdat-compatible.
2132 bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat) {
2133  *CtorComdat = false;
2134  GlobalsMD.init(M);
2135 
2136  SmallVector<GlobalVariable *, 16> GlobalsToChange;
2137 
2138  for (auto &G : M.globals()) {
2139  if (ShouldInstrumentGlobal(&G)) GlobalsToChange.push_back(&G);
2140  }
2141 
2142  size_t n = GlobalsToChange.size();
2143  if (n == 0) {
2144  *CtorComdat = true;
2145  return false;
2146  }
2147 
2148  auto &DL = M.getDataLayout();
2149 
2150  // A global is described by a structure
2151  // size_t beg;
2152  // size_t size;
2153  // size_t size_with_redzone;
2154  // const char *name;
2155  // const char *module_name;
2156  // size_t has_dynamic_init;
2157  // void *source_location;
2158  // size_t odr_indicator;
2159  // We initialize an array of such structures and pass it to a run-time call.
2160  StructType *GlobalStructTy =
2161  StructType::get(IntptrTy, IntptrTy, IntptrTy, IntptrTy, IntptrTy,
2162  IntptrTy, IntptrTy, IntptrTy);
2163  SmallVector<GlobalVariable *, 16> NewGlobals(n);
2164  SmallVector<Constant *, 16> Initializers(n);
2165 
2166  bool HasDynamicallyInitializedGlobals = false;
2167 
2168  // We shouldn't merge same module names, as this string serves as unique
2169  // module ID in runtime.
2171  M, M.getModuleIdentifier(), /*AllowMerging*/ false, kAsanGenPrefix);
2172 
2173  for (size_t i = 0; i < n; i++) {
2174  static const uint64_t kMaxGlobalRedzone = 1 << 18;
2175  GlobalVariable *G = GlobalsToChange[i];
2176 
2177  auto MD = GlobalsMD.get(G);
2178  StringRef NameForGlobal = G->getName();
2179  // Create string holding the global name (use global name from metadata
2180  // if it's available, otherwise just write the name of global variable).
2182  M, MD.Name.empty() ? NameForGlobal : MD.Name,
2183  /*AllowMerging*/ true, kAsanGenPrefix);
2184 
2185  Type *Ty = G->getValueType();
2186  uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
2187  uint64_t MinRZ = MinRedzoneSizeForGlobal();
2188  // MinRZ <= RZ <= kMaxGlobalRedzone
2189  // and trying to make RZ to be ~ 1/4 of SizeInBytes.
2190  uint64_t RZ = std::max(
2191  MinRZ, std::min(kMaxGlobalRedzone, (SizeInBytes / MinRZ / 4) * MinRZ));
2192  uint64_t RightRedzoneSize = RZ;
2193  // Round up to MinRZ
2194  if (SizeInBytes % MinRZ) RightRedzoneSize += MinRZ - (SizeInBytes % MinRZ);
2195  assert(((RightRedzoneSize + SizeInBytes) % MinRZ) == 0);
2196  Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
2197 
2198  StructType *NewTy = StructType::get(Ty, RightRedZoneTy);
2199  Constant *NewInitializer = ConstantStruct::get(
2200  NewTy, G->getInitializer(), Constant::getNullValue(RightRedZoneTy));
2201 
2202  // Create a new global variable with enough space for a redzone.
2203  GlobalValue::LinkageTypes Linkage = G->getLinkage();
2204  if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
2205  Linkage = GlobalValue::InternalLinkage;
2206  GlobalVariable *NewGlobal =
2207  new GlobalVariable(M, NewTy, G->isConstant(), Linkage, NewInitializer,
2208  "", G, G->getThreadLocalMode());
2209  NewGlobal->copyAttributesFrom(G);
2210  NewGlobal->setComdat(G->getComdat());
2211  NewGlobal->setAlignment(MinRZ);
2212 
2213  // Move null-terminated C strings to "__asan_cstring" section on Darwin.
2214  if (TargetTriple.isOSBinFormatMachO() && !G->hasSection() &&
2215  G->isConstant()) {
2216  auto Seq = dyn_cast<ConstantDataSequential>(G->getInitializer());
2217  if (Seq && Seq->isCString())
2218  NewGlobal->setSection("__TEXT,__asan_cstring,regular");
2219  }
2220 
2221  // Transfer the debug info. The payload starts at offset zero so we can
2222  // copy the debug info over as is.
2224  G->getDebugInfo(GVs);
2225  for (auto *GV : GVs)
2226  NewGlobal->addDebugInfo(GV);
2227 
2228  Value *Indices2[2];
2229  Indices2[0] = IRB.getInt32(0);
2230  Indices2[1] = IRB.getInt32(0);
2231 
2232  G->replaceAllUsesWith(
2233  ConstantExpr::getGetElementPtr(NewTy, NewGlobal, Indices2, true));
2234  NewGlobal->takeName(G);
2235  G->eraseFromParent();
2236  NewGlobals[i] = NewGlobal;
2237 
2238  Constant *SourceLoc;
2239  if (!MD.SourceLoc.empty()) {
2240  auto SourceLocGlobal = createPrivateGlobalForSourceLoc(M, MD.SourceLoc);
2241  SourceLoc = ConstantExpr::getPointerCast(SourceLocGlobal, IntptrTy);
2242  } else {
2243  SourceLoc = ConstantInt::get(IntptrTy, 0);
2244  }
2245 
2246  Constant *ODRIndicator = ConstantExpr::getNullValue(IRB.getInt8PtrTy());
2247  GlobalValue *InstrumentedGlobal = NewGlobal;
2248 
2249  bool CanUsePrivateAliases =
2250  TargetTriple.isOSBinFormatELF() || TargetTriple.isOSBinFormatMachO() ||
2251  TargetTriple.isOSBinFormatWasm();
2252  if (CanUsePrivateAliases && ClUsePrivateAliasForGlobals) {
2253  // Create local alias for NewGlobal to avoid crash on ODR between
2254  // instrumented and non-instrumented libraries.
2256  NameForGlobal + M.getName(), NewGlobal);
2257 
2258  // With local aliases, we need to provide another externally visible
2259  // symbol __odr_asan_XXX to detect ODR violation.
2260  auto *ODRIndicatorSym =
2261  new GlobalVariable(M, IRB.getInt8Ty(), false, Linkage,
2263  kODRGenPrefix + NameForGlobal, nullptr,
2264  NewGlobal->getThreadLocalMode());
2265 
2266  // Set meaningful attributes for indicator symbol.
2267  ODRIndicatorSym->setVisibility(NewGlobal->getVisibility());
2268  ODRIndicatorSym->setDLLStorageClass(NewGlobal->getDLLStorageClass());
2269  ODRIndicatorSym->setAlignment(1);
2270  ODRIndicator = ODRIndicatorSym;
2271  InstrumentedGlobal = GA;
2272  }
2273 
2274  Constant *Initializer = ConstantStruct::get(
2275  GlobalStructTy,
2276  ConstantExpr::getPointerCast(InstrumentedGlobal, IntptrTy),
2277  ConstantInt::get(IntptrTy, SizeInBytes),
2278  ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
2279  ConstantExpr::getPointerCast(Name, IntptrTy),
2280  ConstantExpr::getPointerCast(ModuleName, IntptrTy),
2281  ConstantInt::get(IntptrTy, MD.IsDynInit), SourceLoc,
2282  ConstantExpr::getPointerCast(ODRIndicator, IntptrTy));
2283 
2284  if (ClInitializers && MD.IsDynInit) HasDynamicallyInitializedGlobals = true;
2285 
2286  LLVM_DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
2287 
2288  Initializers[i] = Initializer;
2289  }
2290 
2291  // Add instrumented globals to llvm.compiler.used list to avoid LTO from
2292  // ConstantMerge'ing them.
2293  SmallVector<GlobalValue *, 16> GlobalsToAddToUsedList;
2294  for (size_t i = 0; i < n; i++) {
2295  GlobalVariable *G = NewGlobals[i];
2296  if (G->getName().empty()) continue;
2297  GlobalsToAddToUsedList.push_back(G);
2298  }
2299  appendToCompilerUsed(M, ArrayRef<GlobalValue *>(GlobalsToAddToUsedList));
2300 
2301  std::string ELFUniqueModuleId =
2302  (UseGlobalsGC && TargetTriple.isOSBinFormatELF()) ? getUniqueModuleId(&M)
2303  : "";
2304 
2305  if (!ELFUniqueModuleId.empty()) {
2306  InstrumentGlobalsELF(IRB, M, NewGlobals, Initializers, ELFUniqueModuleId);
2307  *CtorComdat = true;
2308  } else if (UseGlobalsGC && TargetTriple.isOSBinFormatCOFF()) {
2309  InstrumentGlobalsCOFF(IRB, M, NewGlobals, Initializers);
2310  } else if (UseGlobalsGC && ShouldUseMachOGlobalsSection()) {
2311  InstrumentGlobalsMachO(IRB, M, NewGlobals, Initializers);
2312  } else {
2313  InstrumentGlobalsWithMetadataArray(IRB, M, NewGlobals, Initializers);
2314  }
2315 
2316  // Create calls for poisoning before initializers run and unpoisoning after.
2317  if (HasDynamicallyInitializedGlobals)
2318  createInitializerPoisonCalls(M, ModuleName);
2319 
2320  LLVM_DEBUG(dbgs() << M);
2321  return true;
2322 }
2323 
2324 int AddressSanitizerModule::GetAsanVersion(const Module &M) const {
2325  int LongSize = M.getDataLayout().getPointerSizeInBits();
2326  bool isAndroid = Triple(M.getTargetTriple()).isAndroid();
2327  int Version = 8;
2328  // 32-bit Android is one version ahead because of the switch to dynamic
2329  // shadow.
2330  Version += (LongSize == 32 && isAndroid);
2331  return Version;
2332 }
2333 
2335  C = &(M.getContext());
2336  int LongSize = M.getDataLayout().getPointerSizeInBits();
2337  IntptrTy = Type::getIntNTy(*C, LongSize);
2338  TargetTriple = Triple(M.getTargetTriple());
2339  Mapping = getShadowMapping(TargetTriple, LongSize, CompileKernel);
2340  initializeCallbacks(M);
2341 
2342  if (CompileKernel)
2343  return false;
2344 
2345  // Create a module constructor. A destructor is created lazily because not all
2346  // platforms, and not all modules need it.
2347  std::string VersionCheckName =
2348  kAsanVersionCheckNamePrefix + std::to_string(GetAsanVersion(M));
2349  std::tie(AsanCtorFunction, std::ignore) = createSanitizerCtorAndInitFunctions(
2350  M, kAsanModuleCtorName, kAsanInitName, /*InitArgTypes=*/{},
2351  /*InitArgs=*/{}, VersionCheckName);
2352 
2353  bool CtorComdat = true;
2354  bool Changed = false;
2355  // TODO(glider): temporarily disabled globals instrumentation for KASan.
2356  if (ClGlobals) {
2357  IRBuilder<> IRB(AsanCtorFunction->getEntryBlock().getTerminator());
2358  Changed |= InstrumentGlobals(IRB, M, &CtorComdat);
2359  }
2360 
2361  // Put the constructor and destructor in comdat if both
2362  // (1) global instrumentation is not TU-specific
2363  // (2) target is ELF.
2364  if (UseCtorComdat && TargetTriple.isOSBinFormatELF() && CtorComdat) {
2365  AsanCtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleCtorName));
2366  appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndDtorPriority,
2367  AsanCtorFunction);
2368  if (AsanDtorFunction) {
2369  AsanDtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleDtorName));
2370  appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndDtorPriority,
2371  AsanDtorFunction);
2372  }
2373  } else {
2374  appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndDtorPriority);
2375  if (AsanDtorFunction)
2376  appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndDtorPriority);
2377  }
2378 
2379  return Changed;
2380 }
2381 
2382 void AddressSanitizer::initializeCallbacks(Module &M) {
2383  IRBuilder<> IRB(*C);
2384  // Create __asan_report* callbacks.
2385  // IsWrite, TypeSize and Exp are encoded in the function name.
2386  for (int Exp = 0; Exp < 2; Exp++) {
2387  for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
2388  const std::string TypeStr = AccessIsWrite ? "store" : "load";
2389  const std::string ExpStr = Exp ? "exp_" : "";
2390  const std::string EndingStr = Recover ? "_noabort" : "";
2391 
2392  SmallVector<Type *, 3> Args2 = {IntptrTy, IntptrTy};
2393  SmallVector<Type *, 2> Args1{1, IntptrTy};
2394  if (Exp) {
2395  Type *ExpType = Type::getInt32Ty(*C);
2396  Args2.push_back(ExpType);
2397  Args1.push_back(ExpType);
2398  }
2399  AsanErrorCallbackSized[AccessIsWrite][Exp] =
2401  kAsanReportErrorTemplate + ExpStr + TypeStr + "_n" + EndingStr,
2402  FunctionType::get(IRB.getVoidTy(), Args2, false)));
2403 
2404  AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] =
2406  ClMemoryAccessCallbackPrefix + ExpStr + TypeStr + "N" + EndingStr,
2407  FunctionType::get(IRB.getVoidTy(), Args2, false)));
2408 
2409  for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
2410  AccessSizeIndex++) {
2411  const std::string Suffix = TypeStr + itostr(1ULL << AccessSizeIndex);
2412  AsanErrorCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2414  kAsanReportErrorTemplate + ExpStr + Suffix + EndingStr,
2415  FunctionType::get(IRB.getVoidTy(), Args1, false)));
2416 
2417  AsanMemoryAccessCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2419  ClMemoryAccessCallbackPrefix + ExpStr + Suffix + EndingStr,
2420  FunctionType::get(IRB.getVoidTy(), Args1, false)));
2421  }
2422  }
2423  }
2424 
2425  const std::string MemIntrinCallbackPrefix =
2426  CompileKernel ? std::string("") : ClMemoryAccessCallbackPrefix;
2428  MemIntrinCallbackPrefix + "memmove", IRB.getInt8PtrTy(),
2429  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy));
2431  MemIntrinCallbackPrefix + "memcpy", IRB.getInt8PtrTy(),
2432  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy));
2434  MemIntrinCallbackPrefix + "memset", IRB.getInt8PtrTy(),
2435  IRB.getInt8PtrTy(), IRB.getInt32Ty(), IntptrTy));
2436 
2437  AsanHandleNoReturnFunc = checkSanitizerInterfaceFunction(
2438  M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy()));
2439 
2441  kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy));
2443  kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy));
2444  // We insert an empty inline asm after __asan_report* to avoid callback merge.
2445  EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
2446  StringRef(""), StringRef(""),
2447  /*hasSideEffects=*/true);
2448  if (Mapping.InGlobal)
2449  AsanShadowGlobal = M.getOrInsertGlobal("__asan_shadow",
2450  ArrayType::get(IRB.getInt8Ty(), 0));
2451 }
2452 
2453 bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
2454  // For each NSObject descendant having a +load method, this method is invoked
2455  // by the ObjC runtime before any of the static constructors is called.
2456  // Therefore we need to instrument such methods with a call to __asan_init
2457  // at the beginning in order to initialize our runtime before any access to
2458  // the shadow memory.
2459  // We cannot just ignore these methods, because they may call other
2460  // instrumented functions.
2461  if (F.getName().find(" load]") != std::string::npos) {
2462  Function *AsanInitFunction =
2464  IRBuilder<> IRB(&F.front(), F.front().begin());
2465  IRB.CreateCall(AsanInitFunction, {});
2466  return true;
2467  }
2468  return false;
2469 }
2470 
2471 void AddressSanitizer::maybeInsertDynamicShadowAtFunctionEntry(Function &F) {
2472  // Generate code only when dynamic addressing is needed.
2473  if (Mapping.Offset != kDynamicShadowSentinel)
2474  return;
2475 
2476  IRBuilder<> IRB(&F.front().front());
2477  if (Mapping.InGlobal) {
2479  // An empty inline asm with input reg == output reg.
2480  // An opaque pointer-to-int cast, basically.
2482  FunctionType::get(IntptrTy, {AsanShadowGlobal->getType()}, false),
2483  StringRef(""), StringRef("=r,0"),
2484  /*hasSideEffects=*/false);
2485  LocalDynamicShadow =
2486  IRB.CreateCall(Asm, {AsanShadowGlobal}, ".asan.shadow");
2487  } else {
2488  LocalDynamicShadow =
2489  IRB.CreatePointerCast(AsanShadowGlobal, IntptrTy, ".asan.shadow");
2490  }
2491  } else {
2492  Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
2493  kAsanShadowMemoryDynamicAddress, IntptrTy);
2494  LocalDynamicShadow = IRB.CreateLoad(GlobalDynamicAddress);
2495  }
2496 }
2497 
2498 void AddressSanitizer::markEscapedLocalAllocas(Function &F) {
2499  // Find the one possible call to llvm.localescape and pre-mark allocas passed
2500  // to it as uninteresting. This assumes we haven't started processing allocas
2501  // yet. This check is done up front because iterating the use list in
2502  // isInterestingAlloca would be algorithmically slower.
2503  assert(ProcessedAllocas.empty() && "must process localescape before allocas");
2504 
2505  // Try to get the declaration of llvm.localescape. If it's not in the module,
2506  // we can exit early.
2507  if (!F.getParent()->getFunction("llvm.localescape")) return;
2508 
2509  // Look for a call to llvm.localescape call in the entry block. It can't be in
2510  // any other block.
2511  for (Instruction &I : F.getEntryBlock()) {
2513  if (II && II->getIntrinsicID() == Intrinsic::localescape) {
2514  // We found a call. Mark all the allocas passed in as uninteresting.
2515  for (Value *Arg : II->arg_operands()) {
2517  assert(AI && AI->isStaticAlloca() &&
2518  "non-static alloca arg to localescape");
2519  ProcessedAllocas[AI] = false;
2520  }
2521  break;
2522  }
2523  }
2524 }
2525 
2527  if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
2528  if (!ClDebugFunc.empty() && ClDebugFunc == F.getName()) return false;
2529  if (F.getName().startswith("__asan_")) return false;
2530 
2531  bool FunctionModified = false;
2532 
2533  // If needed, insert __asan_init before checking for SanitizeAddress attr.
2534  // This function needs to be called even if the function body is not
2535  // instrumented.
2536  if (maybeInsertAsanInitAtFunctionEntry(F))
2537  FunctionModified = true;
2538 
2539  // Leave if the function doesn't need instrumentation.
2540  if (!F.hasFnAttribute(Attribute::SanitizeAddress)) return FunctionModified;
2541 
2542  LLVM_DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
2543 
2544  initializeCallbacks(*F.getParent());
2545 
2546  FunctionStateRAII CleanupObj(this);
2547 
2548  maybeInsertDynamicShadowAtFunctionEntry(F);
2549 
2550  // We can't instrument allocas used with llvm.localescape. Only static allocas
2551  // can be passed to that intrinsic.
2552  markEscapedLocalAllocas(F);
2553 
2554  // We want to instrument every address only once per basic block (unless there
2555  // are calls between uses).
2556  SmallPtrSet<Value *, 16> TempsToInstrument;
2557  SmallVector<Instruction *, 16> ToInstrument;
2558  SmallVector<Instruction *, 8> NoReturnCalls;
2560  SmallVector<Instruction *, 16> PointerComparisonsOrSubtracts;
2561  int NumAllocas = 0;
2562  bool IsWrite;
2563  unsigned Alignment;
2564  uint64_t TypeSize;
2565 
2566  // Fill the set of memory operations to instrument.
2567  for (auto &BB : F) {
2568  AllBlocks.push_back(&BB);
2569  TempsToInstrument.clear();
2570  int NumInsnsPerBB = 0;
2571  for (auto &Inst : BB) {
2572  if (LooksLikeCodeInBug11395(&Inst)) return false;
2573  Value *MaybeMask = nullptr;
2574  if (Value *Addr = isInterestingMemoryAccess(&Inst, &IsWrite, &TypeSize,
2575  &Alignment, &MaybeMask)) {
2576  if (ClOpt && ClOptSameTemp) {
2577  // If we have a mask, skip instrumentation if we've already
2578  // instrumented the full object. But don't add to TempsToInstrument
2579  // because we might get another load/store with a different mask.
2580  if (MaybeMask) {
2581  if (TempsToInstrument.count(Addr))
2582  continue; // We've seen this (whole) temp in the current BB.
2583  } else {
2584  if (!TempsToInstrument.insert(Addr).second)
2585  continue; // We've seen this temp in the current BB.
2586  }
2587  }
2588  } else if (ClInvalidPointerPairs &&
2590  PointerComparisonsOrSubtracts.push_back(&Inst);
2591  continue;
2592  } else if (isa<MemIntrinsic>(Inst)) {
2593  // ok, take it.
2594  } else {
2595  if (isa<AllocaInst>(Inst)) NumAllocas++;
2596  CallSite CS(&Inst);
2597  if (CS) {
2598  // A call inside BB.
2599  TempsToInstrument.clear();
2600  if (CS.doesNotReturn()) NoReturnCalls.push_back(CS.getInstruction());
2601  }
2602  if (CallInst *CI = dyn_cast<CallInst>(&Inst))
2604  continue;
2605  }
2606  ToInstrument.push_back(&Inst);
2607  NumInsnsPerBB++;
2608  if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB) break;
2609  }
2610  }
2611 
2612  bool UseCalls =
2615  const DataLayout &DL = F.getParent()->getDataLayout();
2616  ObjectSizeOpts ObjSizeOpts;
2617  ObjSizeOpts.RoundToAlign = true;
2618  ObjectSizeOffsetVisitor ObjSizeVis(DL, TLI, F.getContext(), ObjSizeOpts);
2619 
2620  // Instrument.
2621  int NumInstrumented = 0;
2622  for (auto Inst : ToInstrument) {
2623  if (ClDebugMin < 0 || ClDebugMax < 0 ||
2624  (NumInstrumented >= ClDebugMin && NumInstrumented <= ClDebugMax)) {
2625  if (isInterestingMemoryAccess(Inst, &IsWrite, &TypeSize, &Alignment))
2626  instrumentMop(ObjSizeVis, Inst, UseCalls,
2627  F.getParent()->getDataLayout());
2628  else
2629  instrumentMemIntrinsic(cast<MemIntrinsic>(Inst));
2630  }
2631  NumInstrumented++;
2632  }
2633 
2634  FunctionStackPoisoner FSP(F, *this);
2635  bool ChangedStack = FSP.runOnFunction();
2636 
2637  // We must unpoison the stack before every NoReturn call (throw, _exit, etc).
2638  // See e.g. https://github.com/google/sanitizers/issues/37
2639  for (auto CI : NoReturnCalls) {
2640  IRBuilder<> IRB(CI);
2641  IRB.CreateCall(AsanHandleNoReturnFunc, {});
2642  }
2643 
2644  for (auto Inst : PointerComparisonsOrSubtracts) {
2645  instrumentPointerComparisonOrSubtraction(Inst);
2646  NumInstrumented++;
2647  }
2648 
2649  if (NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty())
2650  FunctionModified = true;
2651 
2652  LLVM_DEBUG(dbgs() << "ASAN done instrumenting: " << FunctionModified << " "
2653  << F << "\n");
2654 
2655  return FunctionModified;
2656 }
2657 
2658 // Workaround for bug 11395: we don't want to instrument stack in functions
2659 // with large assembly blobs (32-bit only), otherwise reg alloc may crash.
2660 // FIXME: remove once the bug 11395 is fixed.
2661 bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
2662  if (LongSize != 32) return false;
2663  CallInst *CI = dyn_cast<CallInst>(I);
2664  if (!CI || !CI->isInlineAsm()) return false;
2665  if (CI->getNumArgOperands() <= 5) return false;
2666  // We have inline assembly with quite a few arguments.
2667  return true;
2668 }
2669 
2670 void FunctionStackPoisoner::initializeCallbacks(Module &M) {
2671  IRBuilder<> IRB(*C);
2672  for (int i = 0; i <= kMaxAsanStackMallocSizeClass; i++) {
2673  std::string Suffix = itostr(i);
2674  AsanStackMallocFunc[i] = checkSanitizerInterfaceFunction(
2675  M.getOrInsertFunction(kAsanStackMallocNameTemplate + Suffix, IntptrTy,
2676  IntptrTy));
2677  AsanStackFreeFunc[i] = checkSanitizerInterfaceFunction(
2678  M.getOrInsertFunction(kAsanStackFreeNameTemplate + Suffix,
2679  IRB.getVoidTy(), IntptrTy, IntptrTy));
2680  }
2681  if (ASan.UseAfterScope) {
2682  AsanPoisonStackMemoryFunc = checkSanitizerInterfaceFunction(
2683  M.getOrInsertFunction(kAsanPoisonStackMemoryName, IRB.getVoidTy(),
2684  IntptrTy, IntptrTy));
2685  AsanUnpoisonStackMemoryFunc = checkSanitizerInterfaceFunction(
2686  M.getOrInsertFunction(kAsanUnpoisonStackMemoryName, IRB.getVoidTy(),
2687  IntptrTy, IntptrTy));
2688  }
2689 
2690  for (size_t Val : {0x00, 0xf1, 0xf2, 0xf3, 0xf5, 0xf8}) {
2691  std::ostringstream Name;
2692  Name << kAsanSetShadowPrefix;
2693  Name << std::setw(2) << std::setfill('0') << std::hex << Val;
2694  AsanSetShadowFunc[Val] =
2696  Name.str(), IRB.getVoidTy(), IntptrTy, IntptrTy));
2697  }
2698 
2699  AsanAllocaPoisonFunc = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
2700  kAsanAllocaPoison, IRB.getVoidTy(), IntptrTy, IntptrTy));
2701  AsanAllocasUnpoisonFunc =
2703  kAsanAllocasUnpoison, IRB.getVoidTy(), IntptrTy, IntptrTy));
2704 }
2705 
2706 void FunctionStackPoisoner::copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
2707  ArrayRef<uint8_t> ShadowBytes,
2708  size_t Begin, size_t End,
2709  IRBuilder<> &IRB,
2710  Value *ShadowBase) {
2711  if (Begin >= End)
2712  return;
2713 
2714  const size_t LargestStoreSizeInBytes =
2715  std::min<size_t>(sizeof(uint64_t), ASan.LongSize / 8);
2716 
2717  const bool IsLittleEndian = F.getParent()->getDataLayout().isLittleEndian();
2718 
2719  // Poison given range in shadow using larges store size with out leading and
2720  // trailing zeros in ShadowMask. Zeros never change, so they need neither
2721  // poisoning nor up-poisoning. Still we don't mind if some of them get into a
2722  // middle of a store.
2723  for (size_t i = Begin; i < End;) {
2724  if (!ShadowMask[i]) {
2725  assert(!ShadowBytes[i]);
2726  ++i;
2727  continue;
2728  }
2729 
2730  size_t StoreSizeInBytes = LargestStoreSizeInBytes;
2731  // Fit store size into the range.
2732  while (StoreSizeInBytes > End - i)
2733  StoreSizeInBytes /= 2;
2734 
2735  // Minimize store size by trimming trailing zeros.
2736  for (size_t j = StoreSizeInBytes - 1; j && !ShadowMask[i + j]; --j) {
2737  while (j <= StoreSizeInBytes / 2)
2738  StoreSizeInBytes /= 2;
2739  }
2740 
2741  uint64_t Val = 0;
2742  for (size_t j = 0; j < StoreSizeInBytes; j++) {
2743  if (IsLittleEndian)
2744  Val |= (uint64_t)ShadowBytes[i + j] << (8 * j);
2745  else
2746  Val = (Val << 8) | ShadowBytes[i + j];
2747  }
2748 
2749  Value *Ptr = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
2750  Value *Poison = IRB.getIntN(StoreSizeInBytes * 8, Val);
2751  IRB.CreateAlignedStore(
2752  Poison, IRB.CreateIntToPtr(Ptr, Poison->getType()->getPointerTo()), 1);
2753 
2754  i += StoreSizeInBytes;
2755  }
2756 }
2757 
2758 void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2759  ArrayRef<uint8_t> ShadowBytes,
2760  IRBuilder<> &IRB, Value *ShadowBase) {
2761  copyToShadow(ShadowMask, ShadowBytes, 0, ShadowMask.size(), IRB, ShadowBase);
2762 }
2763 
2764 void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2765  ArrayRef<uint8_t> ShadowBytes,
2766  size_t Begin, size_t End,
2767  IRBuilder<> &IRB, Value *ShadowBase) {
2768  assert(ShadowMask.size() == ShadowBytes.size());
2769  size_t Done = Begin;
2770  for (size_t i = Begin, j = Begin + 1; i < End; i = j++) {
2771  if (!ShadowMask[i]) {
2772  assert(!ShadowBytes[i]);
2773  continue;
2774  }
2775  uint8_t Val = ShadowBytes[i];
2776  if (!AsanSetShadowFunc[Val])
2777  continue;
2778 
2779  // Skip same values.
2780  for (; j < End && ShadowMask[j] && Val == ShadowBytes[j]; ++j) {
2781  }
2782 
2783  if (j - i >= ClMaxInlinePoisoningSize) {
2784  copyToShadowInline(ShadowMask, ShadowBytes, Done, i, IRB, ShadowBase);
2785  IRB.CreateCall(AsanSetShadowFunc[Val],
2786  {IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i)),
2787  ConstantInt::get(IntptrTy, j - i)});
2788  Done = j;
2789  }
2790  }
2791 
2792  copyToShadowInline(ShadowMask, ShadowBytes, Done, End, IRB, ShadowBase);
2793 }
2794 
2795 // Fake stack allocator (asan_fake_stack.h) has 11 size classes
2796 // for every power of 2 from kMinStackMallocSize to kMaxAsanStackMallocSizeClass
2797 static int StackMallocSizeClass(uint64_t LocalStackSize) {
2798  assert(LocalStackSize <= kMaxStackMallocSize);
2799  uint64_t MaxSize = kMinStackMallocSize;
2800  for (int i = 0;; i++, MaxSize *= 2)
2801  if (LocalStackSize <= MaxSize) return i;
2802  llvm_unreachable("impossible LocalStackSize");
2803 }
2804 
2805 void FunctionStackPoisoner::copyArgsPassedByValToAllocas() {
2806  Instruction *CopyInsertPoint = &F.front().front();
2807  if (CopyInsertPoint == ASan.LocalDynamicShadow) {
2808  // Insert after the dynamic shadow location is determined
2809  CopyInsertPoint = CopyInsertPoint->getNextNode();
2810  assert(CopyInsertPoint);
2811  }
2812  IRBuilder<> IRB(CopyInsertPoint);
2813  const DataLayout &DL = F.getParent()->getDataLayout();
2814  for (Argument &Arg : F.args()) {
2815  if (Arg.hasByValAttr()) {
2817  unsigned Align = Arg.getParamAlignment();
2818  if (Align == 0) Align = DL.getABITypeAlignment(Ty);
2819 
2820  AllocaInst *AI = IRB.CreateAlloca(
2821  Ty, nullptr,
2822  (Arg.hasName() ? Arg.getName() : "Arg" + Twine(Arg.getArgNo())) +
2823  ".byval");
2824  AI->setAlignment(Align);
2825  Arg.replaceAllUsesWith(AI);
2826 
2827  uint64_t AllocSize = DL.getTypeAllocSize(Ty);
2828  IRB.CreateMemCpy(AI, Align, &Arg, Align, AllocSize);
2829  }
2830  }
2831 }
2832 
2833 PHINode *FunctionStackPoisoner::createPHI(IRBuilder<> &IRB, Value *Cond,
2834  Value *ValueIfTrue,
2835  Instruction *ThenTerm,
2836  Value *ValueIfFalse) {
2837  PHINode *PHI = IRB.CreatePHI(IntptrTy, 2);
2838  BasicBlock *CondBlock = cast<Instruction>(Cond)->getParent();
2839  PHI->addIncoming(ValueIfFalse, CondBlock);
2840  BasicBlock *ThenBlock = ThenTerm->getParent();
2841  PHI->addIncoming(ValueIfTrue, ThenBlock);
2842  return PHI;
2843 }
2844 
2845 Value *FunctionStackPoisoner::createAllocaForLayout(
2846  IRBuilder<> &IRB, const ASanStackFrameLayout &L, bool Dynamic) {
2847  AllocaInst *Alloca;
2848  if (Dynamic) {
2849  Alloca = IRB.CreateAlloca(IRB.getInt8Ty(),
2851  "MyAlloca");
2852  } else {
2853  Alloca = IRB.CreateAlloca(ArrayType::get(IRB.getInt8Ty(), L.FrameSize),
2854  nullptr, "MyAlloca");
2855  assert(Alloca->isStaticAlloca());
2856  }
2857  assert((ClRealignStack & (ClRealignStack - 1)) == 0);
2858  size_t FrameAlignment = std::max(L.FrameAlignment, (size_t)ClRealignStack);
2859  Alloca->setAlignment(FrameAlignment);
2860  return IRB.CreatePointerCast(Alloca, IntptrTy);
2861 }
2862 
2863 void FunctionStackPoisoner::createDynamicAllocasInitStorage() {
2864  BasicBlock &FirstBB = *F.begin();
2865  IRBuilder<> IRB(dyn_cast<Instruction>(FirstBB.begin()));
2866  DynamicAllocaLayout = IRB.CreateAlloca(IntptrTy, nullptr);
2867  IRB.CreateStore(Constant::getNullValue(IntptrTy), DynamicAllocaLayout);
2868  DynamicAllocaLayout->setAlignment(32);
2869 }
2870 
2871 void FunctionStackPoisoner::processDynamicAllocas() {
2872  if (!ClInstrumentDynamicAllocas || DynamicAllocaVec.empty()) {
2873  assert(DynamicAllocaPoisonCallVec.empty());
2874  return;
2875  }
2876 
2877  // Insert poison calls for lifetime intrinsics for dynamic allocas.
2878  for (const auto &APC : DynamicAllocaPoisonCallVec) {
2879  assert(APC.InsBefore);
2880  assert(APC.AI);
2881  assert(ASan.isInterestingAlloca(*APC.AI));
2882  assert(!APC.AI->isStaticAlloca());
2883 
2884  IRBuilder<> IRB(APC.InsBefore);
2885  poisonAlloca(APC.AI, APC.Size, IRB, APC.DoPoison);
2886  // Dynamic allocas will be unpoisoned unconditionally below in
2887  // unpoisonDynamicAllocas.
2888  // Flag that we need unpoison static allocas.
2889  }
2890 
2891  // Handle dynamic allocas.
2892  createDynamicAllocasInitStorage();
2893  for (auto &AI : DynamicAllocaVec)
2894  handleDynamicAllocaCall(AI);
2895  unpoisonDynamicAllocas();
2896 }
2897 
2898 void FunctionStackPoisoner::processStaticAllocas() {
2899  if (AllocaVec.empty()) {
2900  assert(StaticAllocaPoisonCallVec.empty());
2901  return;
2902  }
2903 
2904  int StackMallocIdx = -1;
2905  DebugLoc EntryDebugLocation;
2906  if (auto SP = F.getSubprogram())
2907  EntryDebugLocation = DebugLoc::get(SP->getScopeLine(), 0, SP);
2908 
2909  Instruction *InsBefore = AllocaVec[0];
2910  IRBuilder<> IRB(InsBefore);
2911  IRB.SetCurrentDebugLocation(EntryDebugLocation);
2912 
2913  // Make sure non-instrumented allocas stay in the entry block. Otherwise,
2914  // debug info is broken, because only entry-block allocas are treated as
2915  // regular stack slots.
2916  auto InsBeforeB = InsBefore->getParent();
2917  assert(InsBeforeB == &F.getEntryBlock());
2918  for (auto *AI : StaticAllocasToMoveUp)
2919  if (AI->getParent() == InsBeforeB)
2920  AI->moveBefore(InsBefore);
2921 
2922  // If we have a call to llvm.localescape, keep it in the entry block.
2923  if (LocalEscapeCall) LocalEscapeCall->moveBefore(InsBefore);
2924 
2926  SVD.reserve(AllocaVec.size());
2927  for (AllocaInst *AI : AllocaVec) {
2929  ASan.getAllocaSizeInBytes(*AI),
2930  0,
2931  AI->getAlignment(),
2932  AI,
2933  0,
2934  0};
2935  SVD.push_back(D);
2936  }
2937 
2938  // Minimal header size (left redzone) is 4 pointers,
2939  // i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms.
2940  size_t Granularity = 1ULL << Mapping.Scale;
2941  size_t MinHeaderSize = std::max((size_t)ASan.LongSize / 2, Granularity);
2942  const ASanStackFrameLayout &L =
2943  ComputeASanStackFrameLayout(SVD, Granularity, MinHeaderSize);
2944 
2945  // Build AllocaToSVDMap for ASanStackVariableDescription lookup.
2947  for (auto &Desc : SVD)
2948  AllocaToSVDMap[Desc.AI] = &Desc;
2949 
2950  // Update SVD with information from lifetime intrinsics.
2951  for (const auto &APC : StaticAllocaPoisonCallVec) {
2952  assert(APC.InsBefore);
2953  assert(APC.AI);
2954  assert(ASan.isInterestingAlloca(*APC.AI));
2955  assert(APC.AI->isStaticAlloca());
2956 
2957  ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
2958  Desc.LifetimeSize = Desc.Size;
2959  if (const DILocation *FnLoc = EntryDebugLocation.get()) {
2960  if (const DILocation *LifetimeLoc = APC.InsBefore->getDebugLoc().get()) {
2961  if (LifetimeLoc->getFile() == FnLoc->getFile())
2962  if (unsigned Line = LifetimeLoc->getLine())
2963  Desc.Line = std::min(Desc.Line ? Desc.Line : Line, Line);
2964  }
2965  }
2966  }
2967 
2968  auto DescriptionString = ComputeASanStackFrameDescription(SVD);
2969  LLVM_DEBUG(dbgs() << DescriptionString << " --- " << L.FrameSize << "\n");
2970  uint64_t LocalStackSize = L.FrameSize;
2971  bool DoStackMalloc = ClUseAfterReturn && !ASan.CompileKernel &&
2972  LocalStackSize <= kMaxStackMallocSize;
2973  bool DoDynamicAlloca = ClDynamicAllocaStack;
2974  // Don't do dynamic alloca or stack malloc if:
2975  // 1) There is inline asm: too often it makes assumptions on which registers
2976  // are available.
2977  // 2) There is a returns_twice call (typically setjmp), which is
2978  // optimization-hostile, and doesn't play well with introduced indirect
2979  // register-relative calculation of local variable addresses.
2980  DoDynamicAlloca &= !HasNonEmptyInlineAsm && !HasReturnsTwiceCall;
2981  DoStackMalloc &= !HasNonEmptyInlineAsm && !HasReturnsTwiceCall;
2982 
2983  Value *StaticAlloca =
2984  DoDynamicAlloca ? nullptr : createAllocaForLayout(IRB, L, false);
2985 
2986  Value *FakeStack;
2987  Value *LocalStackBase;
2988  Value *LocalStackBaseAlloca;
2989  bool Deref;
2990 
2991  if (DoStackMalloc) {
2992  LocalStackBaseAlloca =
2993  IRB.CreateAlloca(IntptrTy, nullptr, "asan_local_stack_base");
2994  // void *FakeStack = __asan_option_detect_stack_use_after_return
2995  // ? __asan_stack_malloc_N(LocalStackSize)
2996  // : nullptr;
2997  // void *LocalStackBase = (FakeStack) ? FakeStack : alloca(LocalStackSize);
2998  Constant *OptionDetectUseAfterReturn = F.getParent()->getOrInsertGlobal(
2999  kAsanOptionDetectUseAfterReturn, IRB.getInt32Ty());
3000  Value *UseAfterReturnIsEnabled =
3001  IRB.CreateICmpNE(IRB.CreateLoad(OptionDetectUseAfterReturn),
3003  Instruction *Term =
3004  SplitBlockAndInsertIfThen(UseAfterReturnIsEnabled, InsBefore, false);
3005  IRBuilder<> IRBIf(Term);
3006  IRBIf.SetCurrentDebugLocation(EntryDebugLocation);
3007  StackMallocIdx = StackMallocSizeClass(LocalStackSize);
3008  assert(StackMallocIdx <= kMaxAsanStackMallocSizeClass);
3009  Value *FakeStackValue =
3010  IRBIf.CreateCall(AsanStackMallocFunc[StackMallocIdx],
3011  ConstantInt::get(IntptrTy, LocalStackSize));
3012  IRB.SetInsertPoint(InsBefore);
3013  IRB.SetCurrentDebugLocation(EntryDebugLocation);
3014  FakeStack = createPHI(IRB, UseAfterReturnIsEnabled, FakeStackValue, Term,
3015  ConstantInt::get(IntptrTy, 0));
3016 
3017  Value *NoFakeStack =
3018  IRB.CreateICmpEQ(FakeStack, Constant::getNullValue(IntptrTy));
3019  Term = SplitBlockAndInsertIfThen(NoFakeStack, InsBefore, false);
3020  IRBIf.SetInsertPoint(Term);
3021  IRBIf.SetCurrentDebugLocation(EntryDebugLocation);
3022  Value *AllocaValue =
3023  DoDynamicAlloca ? createAllocaForLayout(IRBIf, L, true) : StaticAlloca;
3024 
3025  IRB.SetInsertPoint(InsBefore);
3026  IRB.SetCurrentDebugLocation(EntryDebugLocation);
3027  LocalStackBase = createPHI(IRB, NoFakeStack, AllocaValue, Term, FakeStack);
3028  IRB.SetCurrentDebugLocation(EntryDebugLocation);
3029  IRB.CreateStore(LocalStackBase, LocalStackBaseAlloca);
3030  Deref = true;
3031  } else {
3032  // void *FakeStack = nullptr;
3033  // void *LocalStackBase = alloca(LocalStackSize);
3034  FakeStack = ConstantInt::get(IntptrTy, 0);
3035  LocalStackBase =
3036  DoDynamicAlloca ? createAllocaForLayout(IRB, L, true) : StaticAlloca;
3037  LocalStackBaseAlloca = LocalStackBase;
3038  Deref = false;
3039  }
3040 
3041  // Replace Alloca instructions with base+offset.
3042  for (const auto &Desc : SVD) {
3043  AllocaInst *AI = Desc.AI;
3044  replaceDbgDeclareForAlloca(AI, LocalStackBaseAlloca, DIB, Deref,
3045  Desc.Offset, DIExpression::NoDeref);
3046  Value *NewAllocaPtr = IRB.CreateIntToPtr(
3047  IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Desc.Offset)),
3048  AI->getType());
3049  AI->replaceAllUsesWith(NewAllocaPtr);
3050  }
3051 
3052  // The left-most redzone has enough space for at least 4 pointers.
3053  // Write the Magic value to redzone[0].
3054  Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
3056  BasePlus0);
3057  // Write the frame description constant to redzone[1].
3058  Value *BasePlus1 = IRB.CreateIntToPtr(
3059  IRB.CreateAdd(LocalStackBase,
3060  ConstantInt::get(IntptrTy, ASan.LongSize / 8)),
3061  IntptrPtrTy);
3062  GlobalVariable *StackDescriptionGlobal =
3063  createPrivateGlobalForString(*F.getParent(), DescriptionString,
3064  /*AllowMerging*/ true, kAsanGenPrefix);
3065  Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal, IntptrTy);
3066  IRB.CreateStore(Description, BasePlus1);
3067  // Write the PC to redzone[2].
3068  Value *BasePlus2 = IRB.CreateIntToPtr(
3069  IRB.CreateAdd(LocalStackBase,
3070  ConstantInt::get(IntptrTy, 2 * ASan.LongSize / 8)),
3071  IntptrPtrTy);
3072  IRB.CreateStore(IRB.CreatePointerCast(&F, IntptrTy), BasePlus2);
3073 
3074  const auto &ShadowAfterScope = GetShadowBytesAfterScope(SVD, L);
3075 
3076  // Poison the stack red zones at the entry.
3077  Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
3078  // As mask we must use most poisoned case: red zones and after scope.
3079  // As bytes we can use either the same or just red zones only.
3080  copyToShadow(ShadowAfterScope, ShadowAfterScope, IRB, ShadowBase);
3081 
3082  if (!StaticAllocaPoisonCallVec.empty()) {
3083  const auto &ShadowInScope = GetShadowBytes(SVD, L);
3084 
3085  // Poison static allocas near lifetime intrinsics.
3086  for (const auto &APC : StaticAllocaPoisonCallVec) {
3087  const ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3088  assert(Desc.Offset % L.Granularity == 0);
3089  size_t Begin = Desc.Offset / L.Granularity;
3090  size_t End = Begin + (APC.Size + L.Granularity - 1) / L.Granularity;
3091 
3092  IRBuilder<> IRB(APC.InsBefore);
3093  copyToShadow(ShadowAfterScope,
3094  APC.DoPoison ? ShadowAfterScope : ShadowInScope, Begin, End,
3095  IRB, ShadowBase);
3096  }
3097  }
3098 
3099  SmallVector<uint8_t, 64> ShadowClean(ShadowAfterScope.size(), 0);
3100  SmallVector<uint8_t, 64> ShadowAfterReturn;
3101 
3102  // (Un)poison the stack before all ret instructions.
3103  for (auto Ret : RetVec) {
3104  IRBuilder<> IRBRet(Ret);
3105  // Mark the current frame as retired.
3107  BasePlus0);
3108  if (DoStackMalloc) {
3109  assert(StackMallocIdx >= 0);
3110  // if FakeStack != 0 // LocalStackBase == FakeStack
3111  // // In use-after-return mode, poison the whole stack frame.
3112  // if StackMallocIdx <= 4
3113  // // For small sizes inline the whole thing:
3114  // memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
3115  // **SavedFlagPtr(FakeStack) = 0
3116  // else
3117  // __asan_stack_free_N(FakeStack, LocalStackSize)
3118  // else
3119  // <This is not a fake stack; unpoison the redzones>
3120  Value *Cmp =
3121  IRBRet.CreateICmpNE(FakeStack, Constant::getNullValue(IntptrTy));
3122  Instruction *ThenTerm, *ElseTerm;
3123  SplitBlockAndInsertIfThenElse(Cmp, Ret, &ThenTerm, &ElseTerm);
3124 
3125  IRBuilder<> IRBPoison(ThenTerm);
3126  if (StackMallocIdx <= 4) {
3127  int ClassSize = kMinStackMallocSize << StackMallocIdx;
3128  ShadowAfterReturn.resize(ClassSize / L.Granularity,
3130  copyToShadow(ShadowAfterReturn, ShadowAfterReturn, IRBPoison,
3131  ShadowBase);
3132  Value *SavedFlagPtrPtr = IRBPoison.CreateAdd(
3133  FakeStack,
3134  ConstantInt::get(IntptrTy, ClassSize - ASan.LongSize / 8));
3135  Value *SavedFlagPtr = IRBPoison.CreateLoad(
3136  IRBPoison.CreateIntToPtr(SavedFlagPtrPtr, IntptrPtrTy));
3137  IRBPoison.CreateStore(
3138  Constant::getNullValue(IRBPoison.getInt8Ty()),
3139  IRBPoison.CreateIntToPtr(SavedFlagPtr, IRBPoison.getInt8PtrTy()));
3140  } else {
3141  // For larger frames call __asan_stack_free_*.
3142  IRBPoison.CreateCall(
3143  AsanStackFreeFunc[StackMallocIdx],
3144  {FakeStack, ConstantInt::get(IntptrTy, LocalStackSize)});
3145  }
3146 
3147  IRBuilder<> IRBElse(ElseTerm);
3148  copyToShadow(ShadowAfterScope, ShadowClean, IRBElse, ShadowBase);
3149  } else {
3150  copyToShadow(ShadowAfterScope, ShadowClean, IRBRet, ShadowBase);
3151  }
3152  }
3153 
3154  // We are done. Remove the old unused alloca instructions.
3155  for (auto AI : AllocaVec) AI->eraseFromParent();
3156 }
3157 
3158 void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
3159  IRBuilder<> &IRB, bool DoPoison) {
3160  // For now just insert the call to ASan runtime.
3161  Value *AddrArg = IRB.CreatePointerCast(V, IntptrTy);
3162  Value *SizeArg = ConstantInt::get(IntptrTy, Size);
3163  IRB.CreateCall(
3164  DoPoison ? AsanPoisonStackMemoryFunc : AsanUnpoisonStackMemoryFunc,
3165  {AddrArg, SizeArg});
3166 }
3167 
3168 // Handling llvm.lifetime intrinsics for a given %alloca:
3169 // (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
3170 // (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
3171 // invalid accesses) and unpoison it for llvm.lifetime.start (the memory
3172 // could be poisoned by previous llvm.lifetime.end instruction, as the
3173 // variable may go in and out of scope several times, e.g. in loops).
3174 // (3) if we poisoned at least one %alloca in a function,
3175 // unpoison the whole stack frame at function exit.
3176 
3177 AllocaInst *FunctionStackPoisoner::findAllocaForValue(Value *V) {
3178  if (AllocaInst *AI = dyn_cast<AllocaInst>(V))
3179  // We're interested only in allocas we can handle.
3180  return ASan.isInterestingAlloca(*AI) ? AI : nullptr;
3181  // See if we've already calculated (or started to calculate) alloca for a
3182  // given value.
3183  AllocaForValueMapTy::iterator I = AllocaForValue.find(V);
3184  if (I != AllocaForValue.end()) return I->second;
3185  // Store 0 while we're calculating alloca for value V to avoid
3186  // infinite recursion if the value references itself.
3187  AllocaForValue[V] = nullptr;
3188  AllocaInst *Res = nullptr;
3189  if (CastInst *CI = dyn_cast<CastInst>(V))
3190  Res = findAllocaForValue(CI->getOperand(0));
3191  else if (PHINode *PN = dyn_cast<PHINode>(V)) {
3192  for (Value *IncValue : PN->incoming_values()) {
3193  // Allow self-referencing phi-nodes.
3194  if (IncValue == PN) continue;
3195  AllocaInst *IncValueAI = findAllocaForValue(IncValue);
3196  // AI for incoming values should exist and should all be equal.
3197  if (IncValueAI == nullptr || (Res != nullptr && IncValueAI != Res))
3198  return nullptr;
3199  Res = IncValueAI;
3200  }
3201  } else if (GetElementPtrInst *EP = dyn_cast<GetElementPtrInst>(V)) {
3202  Res = findAllocaForValue(EP->getPointerOperand());
3203  } else {
3204  LLVM_DEBUG(dbgs() << "Alloca search canceled on unknown instruction: " << *V
3205  << "\n");
3206  }
3207  if (Res) AllocaForValue[V] = Res;
3208  return Res;
3209 }
3210 
3211 void FunctionStackPoisoner::handleDynamicAllocaCall(AllocaInst *AI) {
3212  IRBuilder<> IRB(AI);
3213 
3214  const unsigned Align = std::max(kAllocaRzSize, AI->getAlignment());
3215  const uint64_t AllocaRedzoneMask = kAllocaRzSize - 1;
3216 
3217  Value *Zero = Constant::getNullValue(IntptrTy);
3218  Value *AllocaRzSize = ConstantInt::get(IntptrTy, kAllocaRzSize);
3219  Value *AllocaRzMask = ConstantInt::get(IntptrTy, AllocaRedzoneMask);
3220 
3221  // Since we need to extend alloca with additional memory to locate
3222  // redzones, and OldSize is number of allocated blocks with
3223  // ElementSize size, get allocated memory size in bytes by
3224  // OldSize * ElementSize.
3225  const unsigned ElementSize =
3227  Value *OldSize =
3228  IRB.CreateMul(IRB.CreateIntCast(AI->getArraySize(), IntptrTy, false),
3229  ConstantInt::get(IntptrTy, ElementSize));
3230 
3231  // PartialSize = OldSize % 32
3232  Value *PartialSize = IRB.CreateAnd(OldSize, AllocaRzMask);
3233 
3234  // Misalign = kAllocaRzSize - PartialSize;
3235  Value *Misalign = IRB.CreateSub(AllocaRzSize, PartialSize);
3236 
3237  // PartialPadding = Misalign != kAllocaRzSize ? Misalign : 0;
3238  Value *Cond = IRB.CreateICmpNE(Misalign, AllocaRzSize);
3239  Value *PartialPadding = IRB.CreateSelect(Cond, Misalign, Zero);
3240 
3241  // AdditionalChunkSize = Align + PartialPadding + kAllocaRzSize
3242  // Align is added to locate left redzone, PartialPadding for possible
3243  // partial redzone and kAllocaRzSize for right redzone respectively.
3244  Value *AdditionalChunkSize = IRB.CreateAdd(
3245  ConstantInt::get(IntptrTy, Align + kAllocaRzSize), PartialPadding);
3246 
3247  Value *NewSize = IRB.CreateAdd(OldSize, AdditionalChunkSize);
3248 
3249  // Insert new alloca with new NewSize and Align params.
3250  AllocaInst *NewAlloca = IRB.CreateAlloca(IRB.getInt8Ty(), NewSize);
3251  NewAlloca->setAlignment(Align);
3252 
3253  // NewAddress = Address + Align
3254  Value *NewAddress = IRB.CreateAdd(IRB.CreatePtrToInt(NewAlloca, IntptrTy),
3255  ConstantInt::get(IntptrTy, Align));
3256 
3257  // Insert __asan_alloca_poison call for new created alloca.
3258  IRB.CreateCall(AsanAllocaPoisonFunc, {NewAddress, OldSize});
3259 
3260  // Store the last alloca's address to DynamicAllocaLayout. We'll need this
3261  // for unpoisoning stuff.
3262  IRB.CreateStore(IRB.CreatePtrToInt(NewAlloca, IntptrTy), DynamicAllocaLayout);
3263 
3264  Value *NewAddressPtr = IRB.CreateIntToPtr(NewAddress, AI->getType());
3265 
3266  // Replace all uses of AddessReturnedByAlloca with NewAddressPtr.
3267  AI->replaceAllUsesWith(NewAddressPtr);
3268 
3269  // We are done. Erase old alloca from parent.
3270  AI->eraseFromParent();
3271 }
3272 
3273 // isSafeAccess returns true if Addr is always inbounds with respect to its
3274 // base object. For example, it is a field access or an array access with
3275 // constant inbounds index.
3276 bool AddressSanitizer::isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis,
3277  Value *Addr, uint64_t TypeSize) const {
3278  SizeOffsetType SizeOffset = ObjSizeVis.compute(Addr);
3279  if (!ObjSizeVis.bothKnown(SizeOffset)) return false;
3280  uint64_t Size = SizeOffset.first.getZExtValue();
3281  int64_t Offset = SizeOffset.second.getSExtValue();
3282  // Three checks are required to ensure safety:
3283  // . Offset >= 0 (since the offset is given from the base ptr)
3284  // . Size >= Offset (unsigned)
3285  // . Size - Offset >= NeededSize (unsigned)
3286  return Offset >= 0 && Size >= uint64_t(Offset) &&
3287  Size - uint64_t(Offset) >= TypeSize / 8;
3288 }
void setVisibility(VisibilityTypes V)
Definition: GlobalValue.h:239
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:239
ThreadLocalMode getThreadLocalMode() const
Definition: GlobalValue.h:255
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)
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:436
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:673
static bool GlobalWasGeneratedByCompiler(GlobalVariable *G)
Check if G has been created by a trusted compiler pass.
GCNRegPressure max(const GCNRegPressure &P1, const GCNRegPressure &P2)
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:1304
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:1558
Function * checkSanitizerInterfaceFunction(Constant *FuncOrBitcast)
Value * CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1752
NodeTy * getNextNode()
Get the next node, or nullptr for the list tail.
Definition: ilist_node.h:289
bool hasPrivateLinkage() const
Definition: GlobalValue.h:435
PassT::Result & getResult(IRUnitT &IR, ExtraArgTs... ExtraArgs)
Get the result of an analysis pass for a given IR unit.
Definition: PassManager.h:770
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:143
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:64
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. This instruction must be a terminator.
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
INITIALIZE_PASS_BEGIN(AddressSanitizerLegacyPass, "asan", "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false, false) INITIALIZE_PASS_END(AddressSanitizerLegacyPass
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
INITIALIZE_PASS(AddressSanitizerModuleLegacyPass, "asan-module", "AddressSanitizer: detects use-after-free and out-of-bounds bugs." "ModulePass", false, false) ModulePass *llvm
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:465
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 isInterposable() const
Return true if this global&#39;s definition can be substituted with an arbitrary definition at link time...
Definition: GlobalValue.h:420
bool hasFnAttribute(Attribute::AttrKind Kind) const
Return true if the function has the attribute.
Definition: Function.h:321
The data referenced by the COMDAT must be the same size.
Definition: Comdat.h:39
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:381
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:864
StringRef getName() const
Get a short "name" for the module.
Definition: Module.h:226
static cl::opt< bool > ClUseAfterScope("asan-use-after-scope", cl::desc("Check stack-use-after-scope"), cl::Hidden, cl::init(false))
Analysis pass which computes a DominatorTree.
Definition: Dominators.h:231
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:1069
unsigned getPointerAddressSpace() const
Get the address space of this pointer or pointer vector type.
Definition: DerivedTypes.h:503
bool isOSFuchsia() const
Definition: Triple.h:494
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:116
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:1358
iterator begin()
Instruction iterator methods.
Definition: BasicBlock.h:263
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:1326
bool doesNotReturn() const
Determine if the call cannot return.
Definition: CallSite.h:497
amdgpu Simplify well known AMD library false Value Value const Twine & Name
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:364
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:364
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:243
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:743
This file contains the simple types necessary to represent the attributes associated with functions a...
InstrTy * getInstruction() const
Definition: CallSite.h:92
The linker may choose any COMDAT.
Definition: Comdat.h:35
static const char *const kAsanAllocasUnpoison
Value * CreateAdd(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:974
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:1333
Value * CreateIntToPtr(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1636
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:239
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:594
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:289
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:245
static cl::opt< bool > ClOpt("asan-opt", cl::desc("Optimize instrumentation"), cl::Hidden, cl::init(true))
AddressSanitizerPass(bool CompileKernel=false, bool Recover=false, bool UseAfterScope=false)
MDNode * getMetadata(unsigned KindID) const
Get the metadata of given kind attached to this Instruction.
Definition: Instruction.h:217
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:991
bool isiOS() const
Is this an iOS triple.
Definition: Triple.h:455
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:451
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:482
Debug location.
void takeName(Value *V)
Transfer the name from V to this value.
Definition: Value.cpp:301
iterator begin()
Definition: Function.h:656
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:145
iterator_range< op_iterator > operands()
Definition: Metadata.h:1418
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:1021
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)
static PreservedAnalyses none()
Convenience factory function for the empty preserved set.
Definition: PassManager.h:157
Value * CreateOr(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1142
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:566
ExternalWeak linkage description.
Definition: GlobalValue.h:58
const BasicBlock & getEntryBlock() const
Definition: Function.h:640
an instruction for type-safe pointer arithmetic to access elements of arrays and structs ...
Definition: Instructions.h:843
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:1317
static const size_t kNumberOfAccessSizes
static MDTuple * get(LLVMContext &Context, ArrayRef< Metadata *> MDs)
Definition: Metadata.h:1166
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 Function * Create(FunctionType *Ty, LinkageTypes Linkage, unsigned AddrSpace, const Twine &N="", Module *M=nullptr)
Definition: Function.h:136
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".
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:154
* 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:219
void setDebugLoc(DebugLoc Loc)
Set the debug location information for this instruction.
Definition: Instruction.h:304
DLLStorageClassTypes getDLLStorageClass() const
Definition: GlobalValue.h:259
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:233
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:58
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:295
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:205
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:1913
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:275
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:627
bool isPS4CPU() const
Tests whether the target is the PS4 CPU.
Definition: Triple.h:612
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:1776
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:100
Value * CreateICmpEQ(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1748
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
The data referenced by the COMDAT must be the same.
Definition: Comdat.h:36
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:1933
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:477
const Value * stripPointerCasts() const
Strip off pointer casts, all-zero GEPs, and aliases.
Definition: Value.cpp:539
static PreservedAnalyses all()
Construct a special preserved set that preserves all passes.
Definition: PassManager.h:160
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))
post inline ee instrument
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:209
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.
Value * CreateMul(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1008
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:1878
Value * CreateGEP(Value *Ptr, ArrayRef< Value *> IdxList, const Twine &Name="")
Definition: IRBuilder.h:1386
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:1710
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:576
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)
The linker will choose the largest COMDAT.
Definition: Comdat.h:37
GlobalVariable * createPrivateGlobalForString(Module &M, StringRef Str, bool AllowMerging, const char *NamePrefix="")
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
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
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:445
bool isOSFreeBSD() const
Definition: Triple.h:490
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:175
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:472
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:1687
bool hasComdat() const
Definition: GlobalObject.h:100
void initializeAddressSanitizerLegacyPassPass(PassRegistry &)
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))
Instruction * 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 ...
const Comdat * getComdat() const
Definition: GlobalObject.h:101
void SplitBlockAndInsertIfThenElse(Value *Cond, Instruction *SplitBefore, Instruction **ThenTerm, Instruction **ElseTerm, MDNode *BranchWeights=nullptr)
SplitBlockAndInsertIfThenElse is similar to SplitBlockAndInsertIfThen, but also creates the ElseBlock...
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:668
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:307
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:216
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:653
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
bool hasExactDefinition() const
Return true if this global has an exact defintion.
Definition: GlobalValue.h:407
void copyAttributesFrom(const GlobalVariable *Src)
copyAttributesFrom - copy all additional attributes (those not needed to create a GlobalVariable) fro...
Definition: Globals.cpp:386
const Function * getParent() const
Return the enclosing method, or null if none.
Definition: BasicBlock.h:107
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:276
const BasicBlockListType & getBasicBlockList() const
Get the underlying elements of the Function...
Definition: Function.h:633
static const uint64_t kNetBSD_ShadowOffset64
uint32_t Size
Definition: Profile.cpp:47
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:2785
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:1124
Value * CreatePtrToInt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1631
const std::string to_string(const T &Value)
Definition: ScopedPrinter.h:62
static uint64_t getAllocaSizeInBytes(const AllocaInst &AI)
static const char *const kAsanUnregisterGlobalsName
Analysis pass providing the TargetLibraryInfo.
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:663
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:566
LLVM Value Representation.
Definition: Value.h:73
void setAlignment(unsigned Align)
static const uint64_t kPPC64_ShadowOffset64
static const unsigned kAllocaRzSize
bool hasInitializer() const
Definitions have initializers, declarations don&#39;t.
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:625
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:1084
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:247
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:574
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:604
A container for analyses that lazily runs them and caches their results.
Legacy analysis pass which computes a DominatorTree.
Definition: Dominators.h:260
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:1075
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:123
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:189
#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:423
bool isARM() const
Tests whether the target is ARM (little and big endian).
Definition: Triple.h:658
std::vector< uint32_t > Metadata
PAL metadata represented as a vector.
iterator_range< arg_iterator > args()
Definition: Function.h:689
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:1883
void resize(size_type N)
Definition: SmallVector.h:351