LLVM  9.0.0svn
AddressSanitizer.cpp
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1 //===- AddressSanitizer.cpp - memory error detector -----------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of AddressSanitizer, an address sanity checker.
11 // Details of the algorithm:
12 // https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/SmallPtrSet.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/ADT/StringExtras.h"
23 #include "llvm/ADT/StringRef.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/ADT/Twine.h"
31 #include "llvm/IR/Argument.h"
32 #include "llvm/IR/Attributes.h"
33 #include "llvm/IR/BasicBlock.h"
34 #include "llvm/IR/CallSite.h"
35 #include "llvm/IR/Comdat.h"
36 #include "llvm/IR/Constant.h"
37 #include "llvm/IR/Constants.h"
38 #include "llvm/IR/DIBuilder.h"
39 #include "llvm/IR/DataLayout.h"
41 #include "llvm/IR/DebugLoc.h"
42 #include "llvm/IR/DerivedTypes.h"
43 #include "llvm/IR/Dominators.h"
44 #include "llvm/IR/Function.h"
45 #include "llvm/IR/GlobalAlias.h"
46 #include "llvm/IR/GlobalValue.h"
47 #include "llvm/IR/GlobalVariable.h"
48 #include "llvm/IR/IRBuilder.h"
49 #include "llvm/IR/InlineAsm.h"
50 #include "llvm/IR/InstVisitor.h"
51 #include "llvm/IR/InstrTypes.h"
52 #include "llvm/IR/Instruction.h"
53 #include "llvm/IR/Instructions.h"
54 #include "llvm/IR/IntrinsicInst.h"
55 #include "llvm/IR/Intrinsics.h"
56 #include "llvm/IR/LLVMContext.h"
57 #include "llvm/IR/MDBuilder.h"
58 #include "llvm/IR/Metadata.h"
59 #include "llvm/IR/Module.h"
60 #include "llvm/IR/Type.h"
61 #include "llvm/IR/Use.h"
62 #include "llvm/IR/Value.h"
63 #include "llvm/MC/MCSectionMachO.h"
64 #include "llvm/Pass.h"
65 #include "llvm/Support/Casting.h"
67 #include "llvm/Support/Debug.h"
77 #include <algorithm>
78 #include <cassert>
79 #include <cstddef>
80 #include <cstdint>
81 #include <iomanip>
82 #include <limits>
83 #include <memory>
84 #include <sstream>
85 #include <string>
86 #include <tuple>
87 
88 using namespace llvm;
89 
90 #define DEBUG_TYPE "asan"
91 
92 static const uint64_t kDefaultShadowScale = 3;
93 static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
94 static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
95 static const uint64_t kDynamicShadowSentinel =
97 static const uint64_t kIOSShadowOffset32 = 1ULL << 30;
98 static const uint64_t kIOSSimShadowOffset32 = 1ULL << 30;
100 static const uint64_t kSmallX86_64ShadowOffsetBase = 0x7FFFFFFF; // < 2G.
101 static const uint64_t kSmallX86_64ShadowOffsetAlignMask = ~0xFFFULL;
102 static const uint64_t kLinuxKasan_ShadowOffset64 = 0xdffffc0000000000;
103 static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 44;
104 static const uint64_t kSystemZ_ShadowOffset64 = 1ULL << 52;
105 static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa0000;
106 static const uint64_t kMIPS64_ShadowOffset64 = 1ULL << 37;
107 static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 36;
108 static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
109 static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
110 static const uint64_t kNetBSD_ShadowOffset32 = 1ULL << 30;
111 static const uint64_t kNetBSD_ShadowOffset64 = 1ULL << 46;
112 static const uint64_t kNetBSDKasan_ShadowOffset64 = 0xdfff900000000000;
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  ClUsePrivateAlias("asan-use-private-alias",
349  cl::desc("Use private aliases for global variables"),
350  cl::Hidden, cl::init(false));
351 
352 static cl::opt<bool>
353  ClUseOdrIndicator("asan-use-odr-indicator",
354  cl::desc("Use odr indicators to improve ODR reporting"),
355  cl::Hidden, cl::init(false));
356 
357 static cl::opt<bool>
358  ClUseGlobalsGC("asan-globals-live-support",
359  cl::desc("Use linker features to support dead "
360  "code stripping of globals"),
361  cl::Hidden, cl::init(true));
362 
363 // This is on by default even though there is a bug in gold:
364 // https://sourceware.org/bugzilla/show_bug.cgi?id=19002
365 static cl::opt<bool>
366  ClWithComdat("asan-with-comdat",
367  cl::desc("Place ASan constructors in comdat sections"),
368  cl::Hidden, cl::init(true));
369 
370 // Debug flags.
371 
372 static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
373  cl::init(0));
374 
375 static cl::opt<int> ClDebugStack("asan-debug-stack", cl::desc("debug stack"),
376  cl::Hidden, cl::init(0));
377 
378 static cl::opt<std::string> ClDebugFunc("asan-debug-func", cl::Hidden,
379  cl::desc("Debug func"));
380 
381 static cl::opt<int> ClDebugMin("asan-debug-min", cl::desc("Debug min inst"),
382  cl::Hidden, cl::init(-1));
383 
384 static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug max inst"),
385  cl::Hidden, cl::init(-1));
386 
387 STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
388 STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
389 STATISTIC(NumOptimizedAccessesToGlobalVar,
390  "Number of optimized accesses to global vars");
391 STATISTIC(NumOptimizedAccessesToStackVar,
392  "Number of optimized accesses to stack vars");
393 
394 namespace {
395 
396 /// Frontend-provided metadata for source location.
397 struct LocationMetadata {
398  StringRef Filename;
399  int LineNo = 0;
400  int ColumnNo = 0;
401 
402  LocationMetadata() = default;
403 
404  bool empty() const { return Filename.empty(); }
405 
406  void parse(MDNode *MDN) {
407  assert(MDN->getNumOperands() == 3);
408  MDString *DIFilename = cast<MDString>(MDN->getOperand(0));
409  Filename = DIFilename->getString();
410  LineNo =
411  mdconst::extract<ConstantInt>(MDN->getOperand(1))->getLimitedValue();
412  ColumnNo =
413  mdconst::extract<ConstantInt>(MDN->getOperand(2))->getLimitedValue();
414  }
415 };
416 
417 /// Frontend-provided metadata for global variables.
418 class GlobalsMetadata {
419 public:
420  struct Entry {
421  LocationMetadata SourceLoc;
422  StringRef Name;
423  bool IsDynInit = false;
424  bool IsBlacklisted = false;
425 
426  Entry() = default;
427  };
428 
429  GlobalsMetadata() = default;
430 
431  void reset() {
432  inited_ = false;
433  Entries.clear();
434  }
435 
436  void init(Module &M) {
437  assert(!inited_);
438  inited_ = true;
439  NamedMDNode *Globals = M.getNamedMetadata("llvm.asan.globals");
440  if (!Globals) return;
441  for (auto MDN : Globals->operands()) {
442  // Metadata node contains the global and the fields of "Entry".
443  assert(MDN->getNumOperands() == 5);
444  auto *V = mdconst::extract_or_null<Constant>(MDN->getOperand(0));
445  // The optimizer may optimize away a global entirely.
446  if (!V) continue;
447  auto *StrippedV = V->stripPointerCasts();
448  auto *GV = dyn_cast<GlobalVariable>(StrippedV);
449  if (!GV) continue;
450  // We can already have an entry for GV if it was merged with another
451  // global.
452  Entry &E = Entries[GV];
453  if (auto *Loc = cast_or_null<MDNode>(MDN->getOperand(1)))
454  E.SourceLoc.parse(Loc);
455  if (auto *Name = cast_or_null<MDString>(MDN->getOperand(2)))
456  E.Name = Name->getString();
457  ConstantInt *IsDynInit =
458  mdconst::extract<ConstantInt>(MDN->getOperand(3));
459  E.IsDynInit |= IsDynInit->isOne();
460  ConstantInt *IsBlacklisted =
461  mdconst::extract<ConstantInt>(MDN->getOperand(4));
462  E.IsBlacklisted |= IsBlacklisted->isOne();
463  }
464  }
465 
466  /// Returns metadata entry for a given global.
467  Entry get(GlobalVariable *G) const {
468  auto Pos = Entries.find(G);
469  return (Pos != Entries.end()) ? Pos->second : Entry();
470  }
471 
472 private:
473  bool inited_ = false;
475 };
476 
477 /// This struct defines the shadow mapping using the rule:
478 /// shadow = (mem >> Scale) ADD-or-OR Offset.
479 /// If InGlobal is true, then
480 /// extern char __asan_shadow[];
481 /// shadow = (mem >> Scale) + &__asan_shadow
482 struct ShadowMapping {
483  int Scale;
484  uint64_t Offset;
485  bool OrShadowOffset;
486  bool InGlobal;
487 };
488 
489 } // end anonymous namespace
490 
491 static ShadowMapping getShadowMapping(Triple &TargetTriple, int LongSize,
492  bool IsKasan) {
493  bool IsAndroid = TargetTriple.isAndroid();
494  bool IsIOS = TargetTriple.isiOS() || TargetTriple.isWatchOS();
495  bool IsFreeBSD = TargetTriple.isOSFreeBSD();
496  bool IsNetBSD = TargetTriple.isOSNetBSD();
497  bool IsPS4CPU = TargetTriple.isPS4CPU();
498  bool IsLinux = TargetTriple.isOSLinux();
499  bool IsPPC64 = TargetTriple.getArch() == Triple::ppc64 ||
500  TargetTriple.getArch() == Triple::ppc64le;
501  bool IsSystemZ = TargetTriple.getArch() == Triple::systemz;
502  bool IsX86 = TargetTriple.getArch() == Triple::x86;
503  bool IsX86_64 = TargetTriple.getArch() == Triple::x86_64;
504  bool IsMIPS32 = TargetTriple.isMIPS32();
505  bool IsMIPS64 = TargetTriple.isMIPS64();
506  bool IsArmOrThumb = TargetTriple.isARM() || TargetTriple.isThumb();
507  bool IsAArch64 = TargetTriple.getArch() == Triple::aarch64;
508  bool IsWindows = TargetTriple.isOSWindows();
509  bool IsFuchsia = TargetTriple.isOSFuchsia();
510  bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
511 
512  ShadowMapping Mapping;
513 
514  Mapping.Scale = IsMyriad ? kMyriadShadowScale : kDefaultShadowScale;
515  if (ClMappingScale.getNumOccurrences() > 0) {
516  Mapping.Scale = ClMappingScale;
517  }
518 
519  if (LongSize == 32) {
520  if (IsAndroid)
521  Mapping.Offset = kDynamicShadowSentinel;
522  else if (IsMIPS32)
523  Mapping.Offset = kMIPS32_ShadowOffset32;
524  else if (IsFreeBSD)
525  Mapping.Offset = kFreeBSD_ShadowOffset32;
526  else if (IsNetBSD)
527  Mapping.Offset = kNetBSD_ShadowOffset32;
528  else if (IsIOS)
529  // If we're targeting iOS and x86, the binary is built for iOS simulator.
530  Mapping.Offset = IsX86 ? kIOSSimShadowOffset32 : kIOSShadowOffset32;
531  else if (IsWindows)
532  Mapping.Offset = kWindowsShadowOffset32;
533  else if (IsMyriad) {
534  uint64_t ShadowOffset = (kMyriadMemoryOffset32 + kMyriadMemorySize32 -
535  (kMyriadMemorySize32 >> Mapping.Scale));
536  Mapping.Offset = ShadowOffset - (kMyriadMemoryOffset32 >> Mapping.Scale);
537  }
538  else
539  Mapping.Offset = kDefaultShadowOffset32;
540  } else { // LongSize == 64
541  // Fuchsia is always PIE, which means that the beginning of the address
542  // space is always available.
543  if (IsFuchsia)
544  Mapping.Offset = 0;
545  else if (IsPPC64)
546  Mapping.Offset = kPPC64_ShadowOffset64;
547  else if (IsSystemZ)
548  Mapping.Offset = kSystemZ_ShadowOffset64;
549  else if (IsFreeBSD && !IsMIPS64)
550  Mapping.Offset = kFreeBSD_ShadowOffset64;
551  else if (IsNetBSD) {
552  if (IsKasan)
553  Mapping.Offset = kNetBSDKasan_ShadowOffset64;
554  else
555  Mapping.Offset = kNetBSD_ShadowOffset64;
556  } else if (IsPS4CPU)
557  Mapping.Offset = kPS4CPU_ShadowOffset64;
558  else if (IsLinux && IsX86_64) {
559  if (IsKasan)
560  Mapping.Offset = kLinuxKasan_ShadowOffset64;
561  else
562  Mapping.Offset = (kSmallX86_64ShadowOffsetBase &
563  (kSmallX86_64ShadowOffsetAlignMask << Mapping.Scale));
564  } else if (IsWindows && IsX86_64) {
565  Mapping.Offset = kWindowsShadowOffset64;
566  } else if (IsMIPS64)
567  Mapping.Offset = kMIPS64_ShadowOffset64;
568  else if (IsIOS)
569  // If we're targeting iOS and x86, the binary is built for iOS simulator.
570  // We are using dynamic shadow offset on the 64-bit devices.
571  Mapping.Offset =
573  else if (IsAArch64)
574  Mapping.Offset = kAArch64_ShadowOffset64;
575  else
576  Mapping.Offset = kDefaultShadowOffset64;
577  }
578 
579  if (ClForceDynamicShadow) {
580  Mapping.Offset = kDynamicShadowSentinel;
581  }
582 
583  if (ClMappingOffset.getNumOccurrences() > 0) {
584  Mapping.Offset = ClMappingOffset;
585  }
586 
587  // OR-ing shadow offset if more efficient (at least on x86) if the offset
588  // is a power of two, but on ppc64 we have to use add since the shadow
589  // offset is not necessary 1/8-th of the address space. On SystemZ,
590  // we could OR the constant in a single instruction, but it's more
591  // efficient to load it once and use indexed addressing.
592  Mapping.OrShadowOffset = !IsAArch64 && !IsPPC64 && !IsSystemZ && !IsPS4CPU &&
593  !(Mapping.Offset & (Mapping.Offset - 1)) &&
594  Mapping.Offset != kDynamicShadowSentinel;
595  bool IsAndroidWithIfuncSupport =
596  IsAndroid && !TargetTriple.isAndroidVersionLT(21);
597  Mapping.InGlobal = ClWithIfunc && IsAndroidWithIfuncSupport && IsArmOrThumb;
598 
599  return Mapping;
600 }
601 
602 static size_t RedzoneSizeForScale(int MappingScale) {
603  // Redzone used for stack and globals is at least 32 bytes.
604  // For scales 6 and 7, the redzone has to be 64 and 128 bytes respectively.
605  return std::max(32U, 1U << MappingScale);
606 }
607 
608 namespace {
609 
610 /// AddressSanitizer: instrument the code in module to find memory bugs.
611 struct AddressSanitizer : public FunctionPass {
612  // Pass identification, replacement for typeid
613  static char ID;
614 
615  explicit AddressSanitizer(bool CompileKernel = false, bool Recover = false,
616  bool UseAfterScope = false)
617  : FunctionPass(ID), UseAfterScope(UseAfterScope || ClUseAfterScope) {
618  this->Recover = ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover;
619  this->CompileKernel = ClEnableKasan.getNumOccurrences() > 0 ?
620  ClEnableKasan : CompileKernel;
622  }
623 
624  StringRef getPassName() const override {
625  return "AddressSanitizerFunctionPass";
626  }
627 
628  void getAnalysisUsage(AnalysisUsage &AU) const override {
631  }
632 
633  uint64_t getAllocaSizeInBytes(const AllocaInst &AI) const {
634  uint64_t ArraySize = 1;
635  if (AI.isArrayAllocation()) {
636  const ConstantInt *CI = dyn_cast<ConstantInt>(AI.getArraySize());
637  assert(CI && "non-constant array size");
638  ArraySize = CI->getZExtValue();
639  }
640  Type *Ty = AI.getAllocatedType();
641  uint64_t SizeInBytes =
643  return SizeInBytes * ArraySize;
644  }
645 
646  /// Check if we want (and can) handle this alloca.
647  bool isInterestingAlloca(const AllocaInst &AI);
648 
649  /// If it is an interesting memory access, return the PointerOperand
650  /// and set IsWrite/Alignment. Otherwise return nullptr.
651  /// MaybeMask is an output parameter for the mask Value, if we're looking at a
652  /// masked load/store.
653  Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite,
654  uint64_t *TypeSize, unsigned *Alignment,
655  Value **MaybeMask = nullptr);
656 
657  void instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis, Instruction *I,
658  bool UseCalls, const DataLayout &DL);
659  void instrumentPointerComparisonOrSubtraction(Instruction *I);
660  void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
661  Value *Addr, uint32_t TypeSize, bool IsWrite,
662  Value *SizeArgument, bool UseCalls, uint32_t Exp);
663  void instrumentUnusualSizeOrAlignment(Instruction *I,
664  Instruction *InsertBefore, Value *Addr,
665  uint32_t TypeSize, bool IsWrite,
666  Value *SizeArgument, bool UseCalls,
667  uint32_t Exp);
668  Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
669  Value *ShadowValue, uint32_t TypeSize);
670  Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
671  bool IsWrite, size_t AccessSizeIndex,
672  Value *SizeArgument, uint32_t Exp);
673  void instrumentMemIntrinsic(MemIntrinsic *MI);
674  Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
675  bool runOnFunction(Function &F) override;
676  bool maybeInsertAsanInitAtFunctionEntry(Function &F);
677  void maybeInsertDynamicShadowAtFunctionEntry(Function &F);
678  void markEscapedLocalAllocas(Function &F);
679  bool doInitialization(Module &M) override;
680  bool doFinalization(Module &M) override;
681 
682  DominatorTree &getDominatorTree() const { return *DT; }
683 
684 private:
685  friend struct FunctionStackPoisoner;
686 
687  void initializeCallbacks(Module &M);
688 
689  bool LooksLikeCodeInBug11395(Instruction *I);
690  bool GlobalIsLinkerInitialized(GlobalVariable *G);
691  bool isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis, Value *Addr,
692  uint64_t TypeSize) const;
693 
694  /// Helper to cleanup per-function state.
695  struct FunctionStateRAII {
696  AddressSanitizer *Pass;
697 
698  FunctionStateRAII(AddressSanitizer *Pass) : Pass(Pass) {
699  assert(Pass->ProcessedAllocas.empty() &&
700  "last pass forgot to clear cache");
701  assert(!Pass->LocalDynamicShadow);
702  }
703 
704  ~FunctionStateRAII() {
705  Pass->LocalDynamicShadow = nullptr;
706  Pass->ProcessedAllocas.clear();
707  }
708  };
709 
710  LLVMContext *C;
711  Triple TargetTriple;
712  int LongSize;
713  bool CompileKernel;
714  bool Recover;
715  bool UseAfterScope;
716  Type *IntptrTy;
717  ShadowMapping Mapping;
718  DominatorTree *DT;
719  Function *AsanHandleNoReturnFunc;
720  Function *AsanPtrCmpFunction, *AsanPtrSubFunction;
721  Constant *AsanShadowGlobal;
722 
723  // These arrays is indexed by AccessIsWrite, Experiment and log2(AccessSize).
724  Function *AsanErrorCallback[2][2][kNumberOfAccessSizes];
725  Function *AsanMemoryAccessCallback[2][2][kNumberOfAccessSizes];
726 
727  // These arrays is indexed by AccessIsWrite and Experiment.
728  Function *AsanErrorCallbackSized[2][2];
729  Function *AsanMemoryAccessCallbackSized[2][2];
730 
731  Function *AsanMemmove, *AsanMemcpy, *AsanMemset;
732  InlineAsm *EmptyAsm;
733  Value *LocalDynamicShadow = nullptr;
734  GlobalsMetadata GlobalsMD;
735  DenseMap<const AllocaInst *, bool> ProcessedAllocas;
736 };
737 
738 class AddressSanitizerModule : public ModulePass {
739 public:
740  // Pass identification, replacement for typeid
741  static char ID;
742 
743  explicit AddressSanitizerModule(bool CompileKernel = false,
744  bool Recover = false,
745  bool UseGlobalsGC = true,
746  bool UseOdrIndicator = false)
747  : ModulePass(ID), UseGlobalsGC(UseGlobalsGC && ClUseGlobalsGC),
748  // Enable aliases as they should have no downside with ODR indicators.
749  UsePrivateAlias(UseOdrIndicator || ClUsePrivateAlias),
750  UseOdrIndicator(UseOdrIndicator || ClUseOdrIndicator),
751  // Not a typo: ClWithComdat is almost completely pointless without
752  // ClUseGlobalsGC (because then it only works on modules without
753  // globals, which are rare); it is a prerequisite for ClUseGlobalsGC;
754  // and both suffer from gold PR19002 for which UseGlobalsGC constructor
755  // argument is designed as workaround. Therefore, disable both
756  // ClWithComdat and ClUseGlobalsGC unless the frontend says it's ok to
757  // do globals-gc.
758  UseCtorComdat(UseGlobalsGC && ClWithComdat) {
759  this->Recover = ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover;
760  this->CompileKernel =
761  ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan : CompileKernel;
762  }
763 
764  bool runOnModule(Module &M) override;
765  StringRef getPassName() const override { return "AddressSanitizerModule"; }
766 
767 private:
768  void initializeCallbacks(Module &M);
769 
770  bool InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat);
771  void InstrumentGlobalsCOFF(IRBuilder<> &IRB, Module &M,
772  ArrayRef<GlobalVariable *> ExtendedGlobals,
773  ArrayRef<Constant *> MetadataInitializers);
774  void InstrumentGlobalsELF(IRBuilder<> &IRB, Module &M,
775  ArrayRef<GlobalVariable *> ExtendedGlobals,
776  ArrayRef<Constant *> MetadataInitializers,
777  const std::string &UniqueModuleId);
778  void InstrumentGlobalsMachO(IRBuilder<> &IRB, Module &M,
779  ArrayRef<GlobalVariable *> ExtendedGlobals,
780  ArrayRef<Constant *> MetadataInitializers);
781  void
782  InstrumentGlobalsWithMetadataArray(IRBuilder<> &IRB, Module &M,
783  ArrayRef<GlobalVariable *> ExtendedGlobals,
784  ArrayRef<Constant *> MetadataInitializers);
785 
786  GlobalVariable *CreateMetadataGlobal(Module &M, Constant *Initializer,
787  StringRef OriginalName);
788  void SetComdatForGlobalMetadata(GlobalVariable *G, GlobalVariable *Metadata,
789  StringRef InternalSuffix);
790  IRBuilder<> CreateAsanModuleDtor(Module &M);
791 
792  bool ShouldInstrumentGlobal(GlobalVariable *G);
793  bool ShouldUseMachOGlobalsSection() const;
794  StringRef getGlobalMetadataSection() const;
795  void poisonOneInitializer(Function &GlobalInit, GlobalValue *ModuleName);
796  void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
797  size_t MinRedzoneSizeForGlobal() const {
798  return RedzoneSizeForScale(Mapping.Scale);
799  }
800  int GetAsanVersion(const Module &M) const;
801 
802  GlobalsMetadata GlobalsMD;
803  bool CompileKernel;
804  bool Recover;
805  bool UseGlobalsGC;
806  bool UsePrivateAlias;
807  bool UseOdrIndicator;
808  bool UseCtorComdat;
809  Type *IntptrTy;
810  LLVMContext *C;
811  Triple TargetTriple;
812  ShadowMapping Mapping;
813  Function *AsanPoisonGlobals;
814  Function *AsanUnpoisonGlobals;
815  Function *AsanRegisterGlobals;
816  Function *AsanUnregisterGlobals;
817  Function *AsanRegisterImageGlobals;
818  Function *AsanUnregisterImageGlobals;
819  Function *AsanRegisterElfGlobals;
820  Function *AsanUnregisterElfGlobals;
821 
822  Function *AsanCtorFunction = nullptr;
823  Function *AsanDtorFunction = nullptr;
824 };
825 
826 // Stack poisoning does not play well with exception handling.
827 // When an exception is thrown, we essentially bypass the code
828 // that unpoisones the stack. This is why the run-time library has
829 // to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
830 // stack in the interceptor. This however does not work inside the
831 // actual function which catches the exception. Most likely because the
832 // compiler hoists the load of the shadow value somewhere too high.
833 // This causes asan to report a non-existing bug on 453.povray.
834 // It sounds like an LLVM bug.
835 struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
836  Function &F;
837  AddressSanitizer &ASan;
838  DIBuilder DIB;
839  LLVMContext *C;
840  Type *IntptrTy;
841  Type *IntptrPtrTy;
842  ShadowMapping Mapping;
843 
845  SmallVector<AllocaInst *, 16> StaticAllocasToMoveUp;
847  unsigned StackAlignment;
848 
849  Function *AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
850  *AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
851  Function *AsanSetShadowFunc[0x100] = {};
852  Function *AsanPoisonStackMemoryFunc, *AsanUnpoisonStackMemoryFunc;
853  Function *AsanAllocaPoisonFunc, *AsanAllocasUnpoisonFunc;
854 
855  // Stores a place and arguments of poisoning/unpoisoning call for alloca.
856  struct AllocaPoisonCall {
857  IntrinsicInst *InsBefore;
858  AllocaInst *AI;
859  uint64_t Size;
860  bool DoPoison;
861  };
862  SmallVector<AllocaPoisonCall, 8> DynamicAllocaPoisonCallVec;
863  SmallVector<AllocaPoisonCall, 8> StaticAllocaPoisonCallVec;
864 
865  SmallVector<AllocaInst *, 1> DynamicAllocaVec;
866  SmallVector<IntrinsicInst *, 1> StackRestoreVec;
867  AllocaInst *DynamicAllocaLayout = nullptr;
868  IntrinsicInst *LocalEscapeCall = nullptr;
869 
870  // Maps Value to an AllocaInst from which the Value is originated.
871  using AllocaForValueMapTy = DenseMap<Value *, AllocaInst *>;
872  AllocaForValueMapTy AllocaForValue;
873 
874  bool HasNonEmptyInlineAsm = false;
875  bool HasReturnsTwiceCall = false;
876  std::unique_ptr<CallInst> EmptyInlineAsm;
877 
878  FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
879  : F(F),
880  ASan(ASan),
881  DIB(*F.getParent(), /*AllowUnresolved*/ false),
882  C(ASan.C),
883  IntptrTy(ASan.IntptrTy),
884  IntptrPtrTy(PointerType::get(IntptrTy, 0)),
885  Mapping(ASan.Mapping),
886  StackAlignment(1 << Mapping.Scale),
887  EmptyInlineAsm(CallInst::Create(ASan.EmptyAsm)) {}
888 
889  bool runOnFunction() {
890  if (!ClStack) return false;
891 
892  if (ClRedzoneByvalArgs)
893  copyArgsPassedByValToAllocas();
894 
895  // Collect alloca, ret, lifetime instructions etc.
896  for (BasicBlock *BB : depth_first(&F.getEntryBlock())) visit(*BB);
897 
898  if (AllocaVec.empty() && DynamicAllocaVec.empty()) return false;
899 
900  initializeCallbacks(*F.getParent());
901 
902  processDynamicAllocas();
903  processStaticAllocas();
904 
905  if (ClDebugStack) {
906  LLVM_DEBUG(dbgs() << F);
907  }
908  return true;
909  }
910 
911  // Arguments marked with the "byval" attribute are implicitly copied without
912  // using an alloca instruction. To produce redzones for those arguments, we
913  // copy them a second time into memory allocated with an alloca instruction.
914  void copyArgsPassedByValToAllocas();
915 
916  // Finds all Alloca instructions and puts
917  // poisoned red zones around all of them.
918  // Then unpoison everything back before the function returns.
919  void processStaticAllocas();
920  void processDynamicAllocas();
921 
922  void createDynamicAllocasInitStorage();
923 
924  // ----------------------- Visitors.
925  /// Collect all Ret instructions.
926  void visitReturnInst(ReturnInst &RI) { RetVec.push_back(&RI); }
927 
928  /// Collect all Resume instructions.
929  void visitResumeInst(ResumeInst &RI) { RetVec.push_back(&RI); }
930 
931  /// Collect all CatchReturnInst instructions.
932  void visitCleanupReturnInst(CleanupReturnInst &CRI) { RetVec.push_back(&CRI); }
933 
934  void unpoisonDynamicAllocasBeforeInst(Instruction *InstBefore,
935  Value *SavedStack) {
936  IRBuilder<> IRB(InstBefore);
937  Value *DynamicAreaPtr = IRB.CreatePtrToInt(SavedStack, IntptrTy);
938  // When we insert _asan_allocas_unpoison before @llvm.stackrestore, we
939  // need to adjust extracted SP to compute the address of the most recent
940  // alloca. We have a special @llvm.get.dynamic.area.offset intrinsic for
941  // this purpose.
942  if (!isa<ReturnInst>(InstBefore)) {
943  Function *DynamicAreaOffsetFunc = Intrinsic::getDeclaration(
944  InstBefore->getModule(), Intrinsic::get_dynamic_area_offset,
945  {IntptrTy});
946 
947  Value *DynamicAreaOffset = IRB.CreateCall(DynamicAreaOffsetFunc, {});
948 
949  DynamicAreaPtr = IRB.CreateAdd(IRB.CreatePtrToInt(SavedStack, IntptrTy),
950  DynamicAreaOffset);
951  }
952 
953  IRB.CreateCall(AsanAllocasUnpoisonFunc,
954  {IRB.CreateLoad(DynamicAllocaLayout), DynamicAreaPtr});
955  }
956 
957  // Unpoison dynamic allocas redzones.
958  void unpoisonDynamicAllocas() {
959  for (auto &Ret : RetVec)
960  unpoisonDynamicAllocasBeforeInst(Ret, DynamicAllocaLayout);
961 
962  for (auto &StackRestoreInst : StackRestoreVec)
963  unpoisonDynamicAllocasBeforeInst(StackRestoreInst,
964  StackRestoreInst->getOperand(0));
965  }
966 
967  // Deploy and poison redzones around dynamic alloca call. To do this, we
968  // should replace this call with another one with changed parameters and
969  // replace all its uses with new address, so
970  // addr = alloca type, old_size, align
971  // is replaced by
972  // new_size = (old_size + additional_size) * sizeof(type)
973  // tmp = alloca i8, new_size, max(align, 32)
974  // addr = tmp + 32 (first 32 bytes are for the left redzone).
975  // Additional_size is added to make new memory allocation contain not only
976  // requested memory, but also left, partial and right redzones.
977  void handleDynamicAllocaCall(AllocaInst *AI);
978 
979  /// Collect Alloca instructions we want (and can) handle.
980  void visitAllocaInst(AllocaInst &AI) {
981  if (!ASan.isInterestingAlloca(AI)) {
982  if (AI.isStaticAlloca()) {
983  // Skip over allocas that are present *before* the first instrumented
984  // alloca, we don't want to move those around.
985  if (AllocaVec.empty())
986  return;
987 
988  StaticAllocasToMoveUp.push_back(&AI);
989  }
990  return;
991  }
992 
993  StackAlignment = std::max(StackAlignment, AI.getAlignment());
994  if (!AI.isStaticAlloca())
995  DynamicAllocaVec.push_back(&AI);
996  else
997  AllocaVec.push_back(&AI);
998  }
999 
1000  /// Collect lifetime intrinsic calls to check for use-after-scope
1001  /// errors.
1002  void visitIntrinsicInst(IntrinsicInst &II) {
1004  if (ID == Intrinsic::stackrestore) StackRestoreVec.push_back(&II);
1005  if (ID == Intrinsic::localescape) LocalEscapeCall = &II;
1006  if (!ASan.UseAfterScope)
1007  return;
1008  if (!II.isLifetimeStartOrEnd())
1009  return;
1010  // Found lifetime intrinsic, add ASan instrumentation if necessary.
1012  // If size argument is undefined, don't do anything.
1013  if (Size->isMinusOne()) return;
1014  // Check that size doesn't saturate uint64_t and can
1015  // be stored in IntptrTy.
1016  const uint64_t SizeValue = Size->getValue().getLimitedValue();
1017  if (SizeValue == ~0ULL ||
1018  !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
1019  return;
1020  // Find alloca instruction that corresponds to llvm.lifetime argument.
1021  AllocaInst *AI = findAllocaForValue(II.getArgOperand(1));
1022  if (!AI || !ASan.isInterestingAlloca(*AI))
1023  return;
1024  bool DoPoison = (ID == Intrinsic::lifetime_end);
1025  AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
1026  if (AI->isStaticAlloca())
1027  StaticAllocaPoisonCallVec.push_back(APC);
1028  else if (ClInstrumentDynamicAllocas)
1029  DynamicAllocaPoisonCallVec.push_back(APC);
1030  }
1031 
1032  void visitCallSite(CallSite CS) {
1033  Instruction *I = CS.getInstruction();
1034  if (CallInst *CI = dyn_cast<CallInst>(I)) {
1035  HasNonEmptyInlineAsm |= CI->isInlineAsm() &&
1036  !CI->isIdenticalTo(EmptyInlineAsm.get()) &&
1037  I != ASan.LocalDynamicShadow;
1038  HasReturnsTwiceCall |= CI->canReturnTwice();
1039  }
1040  }
1041 
1042  // ---------------------- Helpers.
1043  void initializeCallbacks(Module &M);
1044 
1045  bool doesDominateAllExits(const Instruction *I) const {
1046  for (auto Ret : RetVec) {
1047  if (!ASan.getDominatorTree().dominates(I, Ret)) return false;
1048  }
1049  return true;
1050  }
1051 
1052  /// Finds alloca where the value comes from.
1053  AllocaInst *findAllocaForValue(Value *V);
1054 
1055  // Copies bytes from ShadowBytes into shadow memory for indexes where
1056  // ShadowMask is not zero. If ShadowMask[i] is zero, we assume that
1057  // ShadowBytes[i] is constantly zero and doesn't need to be overwritten.
1058  void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1059  IRBuilder<> &IRB, Value *ShadowBase);
1060  void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1061  size_t Begin, size_t End, IRBuilder<> &IRB,
1062  Value *ShadowBase);
1063  void copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
1064  ArrayRef<uint8_t> ShadowBytes, size_t Begin,
1065  size_t End, IRBuilder<> &IRB, Value *ShadowBase);
1066 
1067  void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
1068 
1069  Value *createAllocaForLayout(IRBuilder<> &IRB, const ASanStackFrameLayout &L,
1070  bool Dynamic);
1071  PHINode *createPHI(IRBuilder<> &IRB, Value *Cond, Value *ValueIfTrue,
1072  Instruction *ThenTerm, Value *ValueIfFalse);
1073 };
1074 
1075 } // end anonymous namespace
1076 
1077 char AddressSanitizer::ID = 0;
1078 
1080  AddressSanitizer, "asan",
1081  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,
1082  false)
1086  AddressSanitizer, "asan",
1087  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,
1088  false)
1089 
1091  bool Recover,
1092  bool UseAfterScope) {
1093  assert(!CompileKernel || Recover);
1094  return new AddressSanitizer(CompileKernel, Recover, UseAfterScope);
1095 }
1096 
1098 
1100  AddressSanitizerModule, "asan-module",
1101  "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
1102  "ModulePass",
1103  false, false)
1104 
1105 ModulePass *llvm::createAddressSanitizerModulePass(bool CompileKernel,
1106  bool Recover,
1107  bool UseGlobalsGC,
1108  bool UseOdrIndicator) {
1109  assert(!CompileKernel || Recover);
1110  return new AddressSanitizerModule(CompileKernel, Recover, UseGlobalsGC,
1111  UseOdrIndicator);
1112 }
1113 
1114 static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
1115  size_t Res = countTrailingZeros(TypeSize / 8);
1117  return Res;
1118 }
1119 
1120 /// Create a global describing a source location.
1122  LocationMetadata MD) {
1123  Constant *LocData[] = {
1124  createPrivateGlobalForString(M, MD.Filename, true, kAsanGenPrefix),
1125  ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.LineNo),
1126  ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.ColumnNo),
1127  };
1128  auto LocStruct = ConstantStruct::getAnon(LocData);
1129  auto GV = new GlobalVariable(M, LocStruct->getType(), true,
1130  GlobalValue::PrivateLinkage, LocStruct,
1131  kAsanGenPrefix);
1133  return GV;
1134 }
1135 
1136 /// Check if \p G has been created by a trusted compiler pass.
1138  // Do not instrument @llvm.global_ctors, @llvm.used, etc.
1139  if (G->getName().startswith("llvm."))
1140  return true;
1141 
1142  // Do not instrument asan globals.
1143  if (G->getName().startswith(kAsanGenPrefix) ||
1144  G->getName().startswith(kSanCovGenPrefix) ||
1145  G->getName().startswith(kODRGenPrefix))
1146  return true;
1147 
1148  // Do not instrument gcov counter arrays.
1149  if (G->getName() == "__llvm_gcov_ctr")
1150  return true;
1151 
1152  return false;
1153 }
1154 
1155 Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
1156  // Shadow >> scale
1157  Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
1158  if (Mapping.Offset == 0) return Shadow;
1159  // (Shadow >> scale) | offset
1160  Value *ShadowBase;
1161  if (LocalDynamicShadow)
1162  ShadowBase = LocalDynamicShadow;
1163  else
1164  ShadowBase = ConstantInt::get(IntptrTy, Mapping.Offset);
1165  if (Mapping.OrShadowOffset)
1166  return IRB.CreateOr(Shadow, ShadowBase);
1167  else
1168  return IRB.CreateAdd(Shadow, ShadowBase);
1169 }
1170 
1171 // Instrument memset/memmove/memcpy
1172 void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
1173  IRBuilder<> IRB(MI);
1174  if (isa<MemTransferInst>(MI)) {
1175  IRB.CreateCall(
1176  isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
1177  {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1178  IRB.CreatePointerCast(MI->getOperand(1), IRB.getInt8PtrTy()),
1179  IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1180  } else if (isa<MemSetInst>(MI)) {
1181  IRB.CreateCall(
1182  AsanMemset,
1183  {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1184  IRB.CreateIntCast(MI->getOperand(1), IRB.getInt32Ty(), false),
1185  IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1186  }
1187  MI->eraseFromParent();
1188 }
1189 
1190 /// Check if we want (and can) handle this alloca.
1191 bool AddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
1192  auto PreviouslySeenAllocaInfo = ProcessedAllocas.find(&AI);
1193 
1194  if (PreviouslySeenAllocaInfo != ProcessedAllocas.end())
1195  return PreviouslySeenAllocaInfo->getSecond();
1196 
1197  bool IsInteresting =
1198  (AI.getAllocatedType()->isSized() &&
1199  // alloca() may be called with 0 size, ignore it.
1200  ((!AI.isStaticAlloca()) || getAllocaSizeInBytes(AI) > 0) &&
1201  // We are only interested in allocas not promotable to registers.
1202  // Promotable allocas are common under -O0.
1204  // inalloca allocas are not treated as static, and we don't want
1205  // dynamic alloca instrumentation for them as well.
1206  !AI.isUsedWithInAlloca() &&
1207  // swifterror allocas are register promoted by ISel
1208  !AI.isSwiftError());
1209 
1210  ProcessedAllocas[&AI] = IsInteresting;
1211  return IsInteresting;
1212 }
1213 
1214 Value *AddressSanitizer::isInterestingMemoryAccess(Instruction *I,
1215  bool *IsWrite,
1216  uint64_t *TypeSize,
1217  unsigned *Alignment,
1218  Value **MaybeMask) {
1219  // Skip memory accesses inserted by another instrumentation.
1220  if (I->getMetadata("nosanitize")) return nullptr;
1221 
1222  // Do not instrument the load fetching the dynamic shadow address.
1223  if (LocalDynamicShadow == I)
1224  return nullptr;
1225 
1226  Value *PtrOperand = nullptr;
1227  const DataLayout &DL = I->getModule()->getDataLayout();
1228  if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
1229  if (!ClInstrumentReads) return nullptr;
1230  *IsWrite = false;
1231  *TypeSize = DL.getTypeStoreSizeInBits(LI->getType());
1232  *Alignment = LI->getAlignment();
1233  PtrOperand = LI->getPointerOperand();
1234  } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
1235  if (!ClInstrumentWrites) return nullptr;
1236  *IsWrite = true;
1237  *TypeSize = DL.getTypeStoreSizeInBits(SI->getValueOperand()->getType());
1238  *Alignment = SI->getAlignment();
1239  PtrOperand = SI->getPointerOperand();
1240  } else if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
1241  if (!ClInstrumentAtomics) return nullptr;
1242  *IsWrite = true;
1243  *TypeSize = DL.getTypeStoreSizeInBits(RMW->getValOperand()->getType());
1244  *Alignment = 0;
1245  PtrOperand = RMW->getPointerOperand();
1246  } else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
1247  if (!ClInstrumentAtomics) return nullptr;
1248  *IsWrite = true;
1249  *TypeSize = DL.getTypeStoreSizeInBits(XCHG->getCompareOperand()->getType());
1250  *Alignment = 0;
1251  PtrOperand = XCHG->getPointerOperand();
1252  } else if (auto CI = dyn_cast<CallInst>(I)) {
1253  auto *F = dyn_cast<Function>(CI->getCalledValue());
1254  if (F && (F->getName().startswith("llvm.masked.load.") ||
1255  F->getName().startswith("llvm.masked.store."))) {
1256  unsigned OpOffset = 0;
1257  if (F->getName().startswith("llvm.masked.store.")) {
1258  if (!ClInstrumentWrites)
1259  return nullptr;
1260  // Masked store has an initial operand for the value.
1261  OpOffset = 1;
1262  *IsWrite = true;
1263  } else {
1264  if (!ClInstrumentReads)
1265  return nullptr;
1266  *IsWrite = false;
1267  }
1268 
1269  auto BasePtr = CI->getOperand(0 + OpOffset);
1270  auto Ty = cast<PointerType>(BasePtr->getType())->getElementType();
1271  *TypeSize = DL.getTypeStoreSizeInBits(Ty);
1272  if (auto AlignmentConstant =
1273  dyn_cast<ConstantInt>(CI->getOperand(1 + OpOffset)))
1274  *Alignment = (unsigned)AlignmentConstant->getZExtValue();
1275  else
1276  *Alignment = 1; // No alignment guarantees. We probably got Undef
1277  if (MaybeMask)
1278  *MaybeMask = CI->getOperand(2 + OpOffset);
1279  PtrOperand = BasePtr;
1280  }
1281  }
1282 
1283  if (PtrOperand) {
1284  // Do not instrument acesses from different address spaces; we cannot deal
1285  // with them.
1286  Type *PtrTy = cast<PointerType>(PtrOperand->getType()->getScalarType());
1287  if (PtrTy->getPointerAddressSpace() != 0)
1288  return nullptr;
1289 
1290  // Ignore swifterror addresses.
1291  // swifterror memory addresses are mem2reg promoted by instruction
1292  // selection. As such they cannot have regular uses like an instrumentation
1293  // function and it makes no sense to track them as memory.
1294  if (PtrOperand->isSwiftError())
1295  return nullptr;
1296  }
1297 
1298  // Treat memory accesses to promotable allocas as non-interesting since they
1299  // will not cause memory violations. This greatly speeds up the instrumented
1300  // executable at -O0.
1302  if (auto AI = dyn_cast_or_null<AllocaInst>(PtrOperand))
1303  return isInterestingAlloca(*AI) ? AI : nullptr;
1304 
1305  return PtrOperand;
1306 }
1307 
1308 static bool isPointerOperand(Value *V) {
1309  return V->getType()->isPointerTy() || isa<PtrToIntInst>(V);
1310 }
1311 
1312 // This is a rough heuristic; it may cause both false positives and
1313 // false negatives. The proper implementation requires cooperation with
1314 // the frontend.
1316  if (ICmpInst *Cmp = dyn_cast<ICmpInst>(I)) {
1317  if (!Cmp->isRelational()) return false;
1318  } else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) {
1319  if (BO->getOpcode() != Instruction::Sub) return false;
1320  } else {
1321  return false;
1322  }
1323  return isPointerOperand(I->getOperand(0)) &&
1325 }
1326 
1327 bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
1328  // If a global variable does not have dynamic initialization we don't
1329  // have to instrument it. However, if a global does not have initializer
1330  // at all, we assume it has dynamic initializer (in other TU).
1331  return G->hasInitializer() && !GlobalsMD.get(G).IsDynInit;
1332 }
1333 
1334 void AddressSanitizer::instrumentPointerComparisonOrSubtraction(
1335  Instruction *I) {
1336  IRBuilder<> IRB(I);
1337  Function *F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
1338  Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
1339  for (Value *&i : Param) {
1340  if (i->getType()->isPointerTy())
1341  i = IRB.CreatePointerCast(i, IntptrTy);
1342  }
1343  IRB.CreateCall(F, Param);
1344 }
1345 
1346 static void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I,
1347  Instruction *InsertBefore, Value *Addr,
1348  unsigned Alignment, unsigned Granularity,
1349  uint32_t TypeSize, bool IsWrite,
1350  Value *SizeArgument, bool UseCalls,
1351  uint32_t Exp) {
1352  // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check
1353  // if the data is properly aligned.
1354  if ((TypeSize == 8 || TypeSize == 16 || TypeSize == 32 || TypeSize == 64 ||
1355  TypeSize == 128) &&
1356  (Alignment >= Granularity || Alignment == 0 || Alignment >= TypeSize / 8))
1357  return Pass->instrumentAddress(I, InsertBefore, Addr, TypeSize, IsWrite,
1358  nullptr, UseCalls, Exp);
1359  Pass->instrumentUnusualSizeOrAlignment(I, InsertBefore, Addr, TypeSize,
1360  IsWrite, nullptr, UseCalls, Exp);
1361 }
1362 
1363 static void instrumentMaskedLoadOrStore(AddressSanitizer *Pass,
1364  const DataLayout &DL, Type *IntptrTy,
1365  Value *Mask, Instruction *I,
1366  Value *Addr, unsigned Alignment,
1367  unsigned Granularity, uint32_t TypeSize,
1368  bool IsWrite, Value *SizeArgument,
1369  bool UseCalls, uint32_t Exp) {
1370  auto *VTy = cast<PointerType>(Addr->getType())->getElementType();
1371  uint64_t ElemTypeSize = DL.getTypeStoreSizeInBits(VTy->getScalarType());
1372  unsigned Num = VTy->getVectorNumElements();
1373  auto Zero = ConstantInt::get(IntptrTy, 0);
1374  for (unsigned Idx = 0; Idx < Num; ++Idx) {
1375  Value *InstrumentedAddress = nullptr;
1376  Instruction *InsertBefore = I;
1377  if (auto *Vector = dyn_cast<ConstantVector>(Mask)) {
1378  // dyn_cast as we might get UndefValue
1379  if (auto *Masked = dyn_cast<ConstantInt>(Vector->getOperand(Idx))) {
1380  if (Masked->isZero())
1381  // Mask is constant false, so no instrumentation needed.
1382  continue;
1383  // If we have a true or undef value, fall through to doInstrumentAddress
1384  // with InsertBefore == I
1385  }
1386  } else {
1387  IRBuilder<> IRB(I);
1388  Value *MaskElem = IRB.CreateExtractElement(Mask, Idx);
1389  Instruction *ThenTerm = SplitBlockAndInsertIfThen(MaskElem, I, false);
1390  InsertBefore = ThenTerm;
1391  }
1392 
1393  IRBuilder<> IRB(InsertBefore);
1394  InstrumentedAddress =
1395  IRB.CreateGEP(Addr, {Zero, ConstantInt::get(IntptrTy, Idx)});
1396  doInstrumentAddress(Pass, I, InsertBefore, InstrumentedAddress, Alignment,
1397  Granularity, ElemTypeSize, IsWrite, SizeArgument,
1398  UseCalls, Exp);
1399  }
1400 }
1401 
1402 void AddressSanitizer::instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
1403  Instruction *I, bool UseCalls,
1404  const DataLayout &DL) {
1405  bool IsWrite = false;
1406  unsigned Alignment = 0;
1407  uint64_t TypeSize = 0;
1408  Value *MaybeMask = nullptr;
1409  Value *Addr =
1410  isInterestingMemoryAccess(I, &IsWrite, &TypeSize, &Alignment, &MaybeMask);
1411  assert(Addr);
1412 
1413  // Optimization experiments.
1414  // The experiments can be used to evaluate potential optimizations that remove
1415  // instrumentation (assess false negatives). Instead of completely removing
1416  // some instrumentation, you set Exp to a non-zero value (mask of optimization
1417  // experiments that want to remove instrumentation of this instruction).
1418  // If Exp is non-zero, this pass will emit special calls into runtime
1419  // (e.g. __asan_report_exp_load1 instead of __asan_report_load1). These calls
1420  // make runtime terminate the program in a special way (with a different
1421  // exit status). Then you run the new compiler on a buggy corpus, collect
1422  // the special terminations (ideally, you don't see them at all -- no false
1423  // negatives) and make the decision on the optimization.
1425 
1426  if (ClOpt && ClOptGlobals) {
1427  // If initialization order checking is disabled, a simple access to a
1428  // dynamically initialized global is always valid.
1430  if (G && (!ClInitializers || GlobalIsLinkerInitialized(G)) &&
1431  isSafeAccess(ObjSizeVis, Addr, TypeSize)) {
1432  NumOptimizedAccessesToGlobalVar++;
1433  return;
1434  }
1435  }
1436 
1437  if (ClOpt && ClOptStack) {
1438  // A direct inbounds access to a stack variable is always valid.
1439  if (isa<AllocaInst>(GetUnderlyingObject(Addr, DL)) &&
1440  isSafeAccess(ObjSizeVis, Addr, TypeSize)) {
1441  NumOptimizedAccessesToStackVar++;
1442  return;
1443  }
1444  }
1445 
1446  if (IsWrite)
1447  NumInstrumentedWrites++;
1448  else
1449  NumInstrumentedReads++;
1450 
1451  unsigned Granularity = 1 << Mapping.Scale;
1452  if (MaybeMask) {
1453  instrumentMaskedLoadOrStore(this, DL, IntptrTy, MaybeMask, I, Addr,
1454  Alignment, Granularity, TypeSize, IsWrite,
1455  nullptr, UseCalls, Exp);
1456  } else {
1457  doInstrumentAddress(this, I, I, Addr, Alignment, Granularity, TypeSize,
1458  IsWrite, nullptr, UseCalls, Exp);
1459  }
1460 }
1461 
1462 Instruction *AddressSanitizer::generateCrashCode(Instruction *InsertBefore,
1463  Value *Addr, bool IsWrite,
1464  size_t AccessSizeIndex,
1465  Value *SizeArgument,
1466  uint32_t Exp) {
1467  IRBuilder<> IRB(InsertBefore);
1468  Value *ExpVal = Exp == 0 ? nullptr : ConstantInt::get(IRB.getInt32Ty(), Exp);
1469  CallInst *Call = nullptr;
1470  if (SizeArgument) {
1471  if (Exp == 0)
1472  Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][0],
1473  {Addr, SizeArgument});
1474  else
1475  Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][1],
1476  {Addr, SizeArgument, ExpVal});
1477  } else {
1478  if (Exp == 0)
1479  Call =
1480  IRB.CreateCall(AsanErrorCallback[IsWrite][0][AccessSizeIndex], Addr);
1481  else
1482  Call = IRB.CreateCall(AsanErrorCallback[IsWrite][1][AccessSizeIndex],
1483  {Addr, ExpVal});
1484  }
1485 
1486  // We don't do Call->setDoesNotReturn() because the BB already has
1487  // UnreachableInst at the end.
1488  // This EmptyAsm is required to avoid callback merge.
1489  IRB.CreateCall(EmptyAsm, {});
1490  return Call;
1491 }
1492 
1493 Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
1494  Value *ShadowValue,
1495  uint32_t TypeSize) {
1496  size_t Granularity = static_cast<size_t>(1) << Mapping.Scale;
1497  // Addr & (Granularity - 1)
1498  Value *LastAccessedByte =
1499  IRB.CreateAnd(AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
1500  // (Addr & (Granularity - 1)) + size - 1
1501  if (TypeSize / 8 > 1)
1502  LastAccessedByte = IRB.CreateAdd(
1503  LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1));
1504  // (uint8_t) ((Addr & (Granularity-1)) + size - 1)
1505  LastAccessedByte =
1506  IRB.CreateIntCast(LastAccessedByte, ShadowValue->getType(), false);
1507  // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
1508  return IRB.CreateICmpSGE(LastAccessedByte, ShadowValue);
1509 }
1510 
1511 void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
1512  Instruction *InsertBefore, Value *Addr,
1513  uint32_t TypeSize, bool IsWrite,
1514  Value *SizeArgument, bool UseCalls,
1515  uint32_t Exp) {
1516  bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
1517 
1518  IRBuilder<> IRB(InsertBefore);
1519  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1520  size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
1521 
1522  if (UseCalls) {
1523  if (Exp == 0)
1524  IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][0][AccessSizeIndex],
1525  AddrLong);
1526  else
1527  IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][1][AccessSizeIndex],
1528  {AddrLong, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1529  return;
1530  }
1531 
1532  if (IsMyriad) {
1533  // Strip the cache bit and do range check.
1534  // AddrLong &= ~kMyriadCacheBitMask32
1535  AddrLong = IRB.CreateAnd(AddrLong, ~kMyriadCacheBitMask32);
1536  // Tag = AddrLong >> kMyriadTagShift
1537  Value *Tag = IRB.CreateLShr(AddrLong, kMyriadTagShift);
1538  // Tag == kMyriadDDRTag
1539  Value *TagCheck =
1540  IRB.CreateICmpEQ(Tag, ConstantInt::get(IntptrTy, kMyriadDDRTag));
1541 
1542  Instruction *TagCheckTerm =
1543  SplitBlockAndInsertIfThen(TagCheck, InsertBefore, false,
1544  MDBuilder(*C).createBranchWeights(1, 100000));
1545  assert(cast<BranchInst>(TagCheckTerm)->isUnconditional());
1546  IRB.SetInsertPoint(TagCheckTerm);
1547  InsertBefore = TagCheckTerm;
1548  }
1549 
1550  Type *ShadowTy =
1551  IntegerType::get(*C, std::max(8U, TypeSize >> Mapping.Scale));
1552  Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
1553  Value *ShadowPtr = memToShadow(AddrLong, IRB);
1554  Value *CmpVal = Constant::getNullValue(ShadowTy);
1555  Value *ShadowValue =
1556  IRB.CreateLoad(IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));
1557 
1558  Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
1559  size_t Granularity = 1ULL << Mapping.Scale;
1560  Instruction *CrashTerm = nullptr;
1561 
1562  if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
1563  // We use branch weights for the slow path check, to indicate that the slow
1564  // path is rarely taken. This seems to be the case for SPEC benchmarks.
1566  Cmp, InsertBefore, false, MDBuilder(*C).createBranchWeights(1, 100000));
1567  assert(cast<BranchInst>(CheckTerm)->isUnconditional());
1568  BasicBlock *NextBB = CheckTerm->getSuccessor(0);
1569  IRB.SetInsertPoint(CheckTerm);
1570  Value *Cmp2 = createSlowPathCmp(IRB, AddrLong, ShadowValue, TypeSize);
1571  if (Recover) {
1572  CrashTerm = SplitBlockAndInsertIfThen(Cmp2, CheckTerm, false);
1573  } else {
1574  BasicBlock *CrashBlock =
1575  BasicBlock::Create(*C, "", NextBB->getParent(), NextBB);
1576  CrashTerm = new UnreachableInst(*C, CrashBlock);
1577  BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
1578  ReplaceInstWithInst(CheckTerm, NewTerm);
1579  }
1580  } else {
1581  CrashTerm = SplitBlockAndInsertIfThen(Cmp, InsertBefore, !Recover);
1582  }
1583 
1584  Instruction *Crash = generateCrashCode(CrashTerm, AddrLong, IsWrite,
1585  AccessSizeIndex, SizeArgument, Exp);
1586  Crash->setDebugLoc(OrigIns->getDebugLoc());
1587 }
1588 
1589 // Instrument unusual size or unusual alignment.
1590 // We can not do it with a single check, so we do 1-byte check for the first
1591 // and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
1592 // to report the actual access size.
1593 void AddressSanitizer::instrumentUnusualSizeOrAlignment(
1594  Instruction *I, Instruction *InsertBefore, Value *Addr, uint32_t TypeSize,
1595  bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp) {
1596  IRBuilder<> IRB(InsertBefore);
1597  Value *Size = ConstantInt::get(IntptrTy, TypeSize / 8);
1598  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1599  if (UseCalls) {
1600  if (Exp == 0)
1601  IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][0],
1602  {AddrLong, Size});
1603  else
1604  IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][1],
1605  {AddrLong, Size, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1606  } else {
1607  Value *LastByte = IRB.CreateIntToPtr(
1608  IRB.CreateAdd(AddrLong, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
1609  Addr->getType());
1610  instrumentAddress(I, InsertBefore, Addr, 8, IsWrite, Size, false, Exp);
1611  instrumentAddress(I, InsertBefore, LastByte, 8, IsWrite, Size, false, Exp);
1612  }
1613 }
1614 
1615 void AddressSanitizerModule::poisonOneInitializer(Function &GlobalInit,
1616  GlobalValue *ModuleName) {
1617  // Set up the arguments to our poison/unpoison functions.
1618  IRBuilder<> IRB(&GlobalInit.front(),
1619  GlobalInit.front().getFirstInsertionPt());
1620 
1621  // Add a call to poison all external globals before the given function starts.
1622  Value *ModuleNameAddr = ConstantExpr::getPointerCast(ModuleName, IntptrTy);
1623  IRB.CreateCall(AsanPoisonGlobals, ModuleNameAddr);
1624 
1625  // Add calls to unpoison all globals before each return instruction.
1626  for (auto &BB : GlobalInit.getBasicBlockList())
1627  if (ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator()))
1628  CallInst::Create(AsanUnpoisonGlobals, "", RI);
1629 }
1630 
1631 void AddressSanitizerModule::createInitializerPoisonCalls(
1632  Module &M, GlobalValue *ModuleName) {
1633  GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
1634  if (!GV)
1635  return;
1636 
1638  if (!CA)
1639  return;
1640 
1641  for (Use &OP : CA->operands()) {
1642  if (isa<ConstantAggregateZero>(OP)) continue;
1643  ConstantStruct *CS = cast<ConstantStruct>(OP);
1644 
1645  // Must have a function or null ptr.
1646  if (Function *F = dyn_cast<Function>(CS->getOperand(1))) {
1647  if (F->getName() == kAsanModuleCtorName) continue;
1648  ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1649  // Don't instrument CTORs that will run before asan.module_ctor.
1650  if (Priority->getLimitedValue() <= kAsanCtorAndDtorPriority) continue;
1651  poisonOneInitializer(*F, ModuleName);
1652  }
1653  }
1654 }
1655 
1656 bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
1657  Type *Ty = G->getValueType();
1658  LLVM_DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
1659 
1660  if (GlobalsMD.get(G).IsBlacklisted) return false;
1661  if (!Ty->isSized()) return false;
1662  if (!G->hasInitializer()) return false;
1663  if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
1664  // Two problems with thread-locals:
1665  // - The address of the main thread's copy can't be computed at link-time.
1666  // - Need to poison all copies, not just the main thread's one.
1667  if (G->isThreadLocal()) return false;
1668  // For now, just ignore this Global if the alignment is large.
1669  if (G->getAlignment() > MinRedzoneSizeForGlobal()) return false;
1670 
1671  // For non-COFF targets, only instrument globals known to be defined by this
1672  // TU.
1673  // FIXME: We can instrument comdat globals on ELF if we are using the
1674  // GC-friendly metadata scheme.
1675  if (!TargetTriple.isOSBinFormatCOFF()) {
1676  if (!G->hasExactDefinition() || G->hasComdat())
1677  return false;
1678  } else {
1679  // On COFF, don't instrument non-ODR linkages.
1680  if (G->isInterposable())
1681  return false;
1682  }
1683 
1684  // If a comdat is present, it must have a selection kind that implies ODR
1685  // semantics: no duplicates, any, or exact match.
1686  if (Comdat *C = G->getComdat()) {
1687  switch (C->getSelectionKind()) {
1688  case Comdat::Any:
1689  case Comdat::ExactMatch:
1690  case Comdat::NoDuplicates:
1691  break;
1692  case Comdat::Largest:
1693  case Comdat::SameSize:
1694  return false;
1695  }
1696  }
1697 
1698  if (G->hasSection()) {
1699  StringRef Section = G->getSection();
1700 
1701  // Globals from llvm.metadata aren't emitted, do not instrument them.
1702  if (Section == "llvm.metadata") return false;
1703  // Do not instrument globals from special LLVM sections.
1704  if (Section.find("__llvm") != StringRef::npos || Section.find("__LLVM") != StringRef::npos) return false;
1705 
1706  // Do not instrument function pointers to initialization and termination
1707  // routines: dynamic linker will not properly handle redzones.
1708  if (Section.startswith(".preinit_array") ||
1709  Section.startswith(".init_array") ||
1710  Section.startswith(".fini_array")) {
1711  return false;
1712  }
1713 
1714  // On COFF, if the section name contains '$', it is highly likely that the
1715  // user is using section sorting to create an array of globals similar to
1716  // the way initialization callbacks are registered in .init_array and
1717  // .CRT$XCU. The ATL also registers things in .ATL$__[azm]. Adding redzones
1718  // to such globals is counterproductive, because the intent is that they
1719  // will form an array, and out-of-bounds accesses are expected.
1720  // See https://github.com/google/sanitizers/issues/305
1721  // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
1722  if (TargetTriple.isOSBinFormatCOFF() && Section.contains('$')) {
1723  LLVM_DEBUG(dbgs() << "Ignoring global in sorted section (contains '$'): "
1724  << *G << "\n");
1725  return false;
1726  }
1727 
1728  if (TargetTriple.isOSBinFormatMachO()) {
1729  StringRef ParsedSegment, ParsedSection;
1730  unsigned TAA = 0, StubSize = 0;
1731  bool TAAParsed;
1732  std::string ErrorCode = MCSectionMachO::ParseSectionSpecifier(
1733  Section, ParsedSegment, ParsedSection, TAA, TAAParsed, StubSize);
1734  assert(ErrorCode.empty() && "Invalid section specifier.");
1735 
1736  // Ignore the globals from the __OBJC section. The ObjC runtime assumes
1737  // those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
1738  // them.
1739  if (ParsedSegment == "__OBJC" ||
1740  (ParsedSegment == "__DATA" && ParsedSection.startswith("__objc_"))) {
1741  LLVM_DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G << "\n");
1742  return false;
1743  }
1744  // See https://github.com/google/sanitizers/issues/32
1745  // Constant CFString instances are compiled in the following way:
1746  // -- the string buffer is emitted into
1747  // __TEXT,__cstring,cstring_literals
1748  // -- the constant NSConstantString structure referencing that buffer
1749  // is placed into __DATA,__cfstring
1750  // Therefore there's no point in placing redzones into __DATA,__cfstring.
1751  // Moreover, it causes the linker to crash on OS X 10.7
1752  if (ParsedSegment == "__DATA" && ParsedSection == "__cfstring") {
1753  LLVM_DEBUG(dbgs() << "Ignoring CFString: " << *G << "\n");
1754  return false;
1755  }
1756  // The linker merges the contents of cstring_literals and removes the
1757  // trailing zeroes.
1758  if (ParsedSegment == "__TEXT" && (TAA & MachO::S_CSTRING_LITERALS)) {
1759  LLVM_DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n");
1760  return false;
1761  }
1762  }
1763  }
1764 
1765  return true;
1766 }
1767 
1768 // On Mach-O platforms, we emit global metadata in a separate section of the
1769 // binary in order to allow the linker to properly dead strip. This is only
1770 // supported on recent versions of ld64.
1771 bool AddressSanitizerModule::ShouldUseMachOGlobalsSection() const {
1772  if (!TargetTriple.isOSBinFormatMachO())
1773  return false;
1774 
1775  if (TargetTriple.isMacOSX() && !TargetTriple.isMacOSXVersionLT(10, 11))
1776  return true;
1777  if (TargetTriple.isiOS() /* or tvOS */ && !TargetTriple.isOSVersionLT(9))
1778  return true;
1779  if (TargetTriple.isWatchOS() && !TargetTriple.isOSVersionLT(2))
1780  return true;
1781 
1782  return false;
1783 }
1784 
1785 StringRef AddressSanitizerModule::getGlobalMetadataSection() const {
1786  switch (TargetTriple.getObjectFormat()) {
1787  case Triple::COFF: return ".ASAN$GL";
1788  case Triple::ELF: return "asan_globals";
1789  case Triple::MachO: return "__DATA,__asan_globals,regular";
1790  default: break;
1791  }
1792  llvm_unreachable("unsupported object format");
1793 }
1794 
1795 void AddressSanitizerModule::initializeCallbacks(Module &M) {
1796  IRBuilder<> IRB(*C);
1797 
1798  // Declare our poisoning and unpoisoning functions.
1800  kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy));
1801  AsanPoisonGlobals->setLinkage(Function::ExternalLinkage);
1802  AsanUnpoisonGlobals = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
1803  kAsanUnpoisonGlobalsName, IRB.getVoidTy()));
1804  AsanUnpoisonGlobals->setLinkage(Function::ExternalLinkage);
1805 
1806  // Declare functions that register/unregister globals.
1807  AsanRegisterGlobals = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
1808  kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy));
1809  AsanRegisterGlobals->setLinkage(Function::ExternalLinkage);
1810  AsanUnregisterGlobals = checkSanitizerInterfaceFunction(
1811  M.getOrInsertFunction(kAsanUnregisterGlobalsName, IRB.getVoidTy(),
1812  IntptrTy, IntptrTy));
1813  AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
1814 
1815  // Declare the functions that find globals in a shared object and then invoke
1816  // the (un)register function on them.
1817  AsanRegisterImageGlobals =
1819  kAsanRegisterImageGlobalsName, IRB.getVoidTy(), IntptrTy));
1820  AsanRegisterImageGlobals->setLinkage(Function::ExternalLinkage);
1821 
1822  AsanUnregisterImageGlobals =
1824  kAsanUnregisterImageGlobalsName, IRB.getVoidTy(), IntptrTy));
1825  AsanUnregisterImageGlobals->setLinkage(Function::ExternalLinkage);
1826 
1827  AsanRegisterElfGlobals = checkSanitizerInterfaceFunction(
1828  M.getOrInsertFunction(kAsanRegisterElfGlobalsName, IRB.getVoidTy(),
1829  IntptrTy, IntptrTy, IntptrTy));
1830  AsanRegisterElfGlobals->setLinkage(Function::ExternalLinkage);
1831 
1832  AsanUnregisterElfGlobals = checkSanitizerInterfaceFunction(
1833  M.getOrInsertFunction(kAsanUnregisterElfGlobalsName, IRB.getVoidTy(),
1834  IntptrTy, IntptrTy, IntptrTy));
1835  AsanUnregisterElfGlobals->setLinkage(Function::ExternalLinkage);
1836 }
1837 
1838 // Put the metadata and the instrumented global in the same group. This ensures
1839 // that the metadata is discarded if the instrumented global is discarded.
1840 void AddressSanitizerModule::SetComdatForGlobalMetadata(
1841  GlobalVariable *G, GlobalVariable *Metadata, StringRef InternalSuffix) {
1842  Module &M = *G->getParent();
1843  Comdat *C = G->getComdat();
1844  if (!C) {
1845  if (!G->hasName()) {
1846  // If G is unnamed, it must be internal. Give it an artificial name
1847  // so we can put it in a comdat.
1848  assert(G->hasLocalLinkage());
1849  G->setName(Twine(kAsanGenPrefix) + "_anon_global");
1850  }
1851 
1852  if (!InternalSuffix.empty() && G->hasLocalLinkage()) {
1853  std::string Name = G->getName();
1854  Name += InternalSuffix;
1855  C = M.getOrInsertComdat(Name);
1856  } else {
1857  C = M.getOrInsertComdat(G->getName());
1858  }
1859 
1860  // Make this IMAGE_COMDAT_SELECT_NODUPLICATES on COFF. Also upgrade private
1861  // linkage to internal linkage so that a symbol table entry is emitted. This
1862  // is necessary in order to create the comdat group.
1863  if (TargetTriple.isOSBinFormatCOFF()) {
1865  if (G->hasPrivateLinkage())
1867  }
1868  G->setComdat(C);
1869  }
1870 
1871  assert(G->hasComdat());
1872  Metadata->setComdat(G->getComdat());
1873 }
1874 
1875 // Create a separate metadata global and put it in the appropriate ASan
1876 // global registration section.
1878 AddressSanitizerModule::CreateMetadataGlobal(Module &M, Constant *Initializer,
1879  StringRef OriginalName) {
1880  auto Linkage = TargetTriple.isOSBinFormatMachO()
1883  GlobalVariable *Metadata = new GlobalVariable(
1884  M, Initializer->getType(), false, Linkage, Initializer,
1885  Twine("__asan_global_") + GlobalValue::dropLLVMManglingEscape(OriginalName));
1886  Metadata->setSection(getGlobalMetadataSection());
1887  return Metadata;
1888 }
1889 
1890 IRBuilder<> AddressSanitizerModule::CreateAsanModuleDtor(Module &M) {
1891  AsanDtorFunction =
1893  GlobalValue::InternalLinkage, kAsanModuleDtorName, &M);
1894  BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
1895 
1896  return IRBuilder<>(ReturnInst::Create(*C, AsanDtorBB));
1897 }
1898 
1899 void AddressSanitizerModule::InstrumentGlobalsCOFF(
1900  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
1901  ArrayRef<Constant *> MetadataInitializers) {
1902  assert(ExtendedGlobals.size() == MetadataInitializers.size());
1903  auto &DL = M.getDataLayout();
1904 
1905  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
1906  Constant *Initializer = MetadataInitializers[i];
1907  GlobalVariable *G = ExtendedGlobals[i];
1908  GlobalVariable *Metadata =
1909  CreateMetadataGlobal(M, Initializer, G->getName());
1910 
1911  // The MSVC linker always inserts padding when linking incrementally. We
1912  // cope with that by aligning each struct to its size, which must be a power
1913  // of two.
1914  unsigned SizeOfGlobalStruct = DL.getTypeAllocSize(Initializer->getType());
1915  assert(isPowerOf2_32(SizeOfGlobalStruct) &&
1916  "global metadata will not be padded appropriately");
1917  Metadata->setAlignment(SizeOfGlobalStruct);
1918 
1919  SetComdatForGlobalMetadata(G, Metadata, "");
1920  }
1921 }
1922 
1923 void AddressSanitizerModule::InstrumentGlobalsELF(
1924  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
1925  ArrayRef<Constant *> MetadataInitializers,
1926  const std::string &UniqueModuleId) {
1927  assert(ExtendedGlobals.size() == MetadataInitializers.size());
1928 
1929  SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
1930  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
1931  GlobalVariable *G = ExtendedGlobals[i];
1932  GlobalVariable *Metadata =
1933  CreateMetadataGlobal(M, MetadataInitializers[i], G->getName());
1935  Metadata->setMetadata(LLVMContext::MD_associated, MD);
1936  MetadataGlobals[i] = Metadata;
1937 
1938  SetComdatForGlobalMetadata(G, Metadata, UniqueModuleId);
1939  }
1940 
1941  // Update llvm.compiler.used, adding the new metadata globals. This is
1942  // needed so that during LTO these variables stay alive.
1943  if (!MetadataGlobals.empty())
1944  appendToCompilerUsed(M, MetadataGlobals);
1945 
1946  // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
1947  // to look up the loaded image that contains it. Second, we can store in it
1948  // whether registration has already occurred, to prevent duplicate
1949  // registration.
1950  //
1951  // Common linkage ensures that there is only one global per shared library.
1952  GlobalVariable *RegisteredFlag = new GlobalVariable(
1953  M, IntptrTy, false, GlobalVariable::CommonLinkage,
1954  ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
1956 
1957  // Create start and stop symbols.
1958  GlobalVariable *StartELFMetadata = new GlobalVariable(
1959  M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
1960  "__start_" + getGlobalMetadataSection());
1962  GlobalVariable *StopELFMetadata = new GlobalVariable(
1963  M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
1964  "__stop_" + getGlobalMetadataSection());
1966 
1967  // Create a call to register the globals with the runtime.
1968  IRB.CreateCall(AsanRegisterElfGlobals,
1969  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
1970  IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
1971  IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
1972 
1973  // We also need to unregister globals at the end, e.g., when a shared library
1974  // gets closed.
1975  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
1976  IRB_Dtor.CreateCall(AsanUnregisterElfGlobals,
1977  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
1978  IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
1979  IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
1980 }
1981 
1982 void AddressSanitizerModule::InstrumentGlobalsMachO(
1983  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
1984  ArrayRef<Constant *> MetadataInitializers) {
1985  assert(ExtendedGlobals.size() == MetadataInitializers.size());
1986 
1987  // On recent Mach-O platforms, use a structure which binds the liveness of
1988  // the global variable to the metadata struct. Keep the list of "Liveness" GV
1989  // created to be added to llvm.compiler.used
1990  StructType *LivenessTy = StructType::get(IntptrTy, IntptrTy);
1991  SmallVector<GlobalValue *, 16> LivenessGlobals(ExtendedGlobals.size());
1992 
1993  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
1994  Constant *Initializer = MetadataInitializers[i];
1995  GlobalVariable *G = ExtendedGlobals[i];
1996  GlobalVariable *Metadata =
1997  CreateMetadataGlobal(M, Initializer, G->getName());
1998 
1999  // On recent Mach-O platforms, we emit the global metadata in a way that
2000  // allows the linker to properly strip dead globals.
2001  auto LivenessBinder =
2002  ConstantStruct::get(LivenessTy, Initializer->getAggregateElement(0u),
2003  ConstantExpr::getPointerCast(Metadata, IntptrTy));
2004  GlobalVariable *Liveness = new GlobalVariable(
2005  M, LivenessTy, false, GlobalVariable::InternalLinkage, LivenessBinder,
2006  Twine("__asan_binder_") + G->getName());
2007  Liveness->setSection("__DATA,__asan_liveness,regular,live_support");
2008  LivenessGlobals[i] = Liveness;
2009  }
2010 
2011  // Update llvm.compiler.used, adding the new liveness globals. This is
2012  // needed so that during LTO these variables stay alive. The alternative
2013  // would be to have the linker handling the LTO symbols, but libLTO
2014  // current API does not expose access to the section for each symbol.
2015  if (!LivenessGlobals.empty())
2016  appendToCompilerUsed(M, LivenessGlobals);
2017 
2018  // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2019  // to look up the loaded image that contains it. Second, we can store in it
2020  // whether registration has already occurred, to prevent duplicate
2021  // registration.
2022  //
2023  // common linkage ensures that there is only one global per shared library.
2024  GlobalVariable *RegisteredFlag = new GlobalVariable(
2025  M, IntptrTy, false, GlobalVariable::CommonLinkage,
2026  ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
2028 
2029  IRB.CreateCall(AsanRegisterImageGlobals,
2030  {IRB.CreatePointerCast(RegisteredFlag, 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(AsanUnregisterImageGlobals,
2036  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2037 }
2038 
2039 void AddressSanitizerModule::InstrumentGlobalsWithMetadataArray(
2040  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2041  ArrayRef<Constant *> MetadataInitializers) {
2042  assert(ExtendedGlobals.size() == MetadataInitializers.size());
2043  unsigned N = ExtendedGlobals.size();
2044  assert(N > 0);
2045 
2046  // On platforms that don't have a custom metadata section, we emit an array
2047  // of global metadata structures.
2048  ArrayType *ArrayOfGlobalStructTy =
2049  ArrayType::get(MetadataInitializers[0]->getType(), N);
2050  auto AllGlobals = new GlobalVariable(
2051  M, ArrayOfGlobalStructTy, false, GlobalVariable::InternalLinkage,
2052  ConstantArray::get(ArrayOfGlobalStructTy, MetadataInitializers), "");
2053  if (Mapping.Scale > 3)
2054  AllGlobals->setAlignment(1ULL << Mapping.Scale);
2055 
2056  IRB.CreateCall(AsanRegisterGlobals,
2057  {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2058  ConstantInt::get(IntptrTy, N)});
2059 
2060  // We also need to unregister globals at the end, e.g., when a shared library
2061  // gets closed.
2062  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2063  IRB_Dtor.CreateCall(AsanUnregisterGlobals,
2064  {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2065  ConstantInt::get(IntptrTy, N)});
2066 }
2067 
2068 // This function replaces all global variables with new variables that have
2069 // trailing redzones. It also creates a function that poisons
2070 // redzones and inserts this function into llvm.global_ctors.
2071 // Sets *CtorComdat to true if the global registration code emitted into the
2072 // asan constructor is comdat-compatible.
2073 bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat) {
2074  *CtorComdat = false;
2075  GlobalsMD.init(M);
2076 
2077  SmallVector<GlobalVariable *, 16> GlobalsToChange;
2078 
2079  for (auto &G : M.globals()) {
2080  if (ShouldInstrumentGlobal(&G)) GlobalsToChange.push_back(&G);
2081  }
2082 
2083  size_t n = GlobalsToChange.size();
2084  if (n == 0) {
2085  *CtorComdat = true;
2086  return false;
2087  }
2088 
2089  auto &DL = M.getDataLayout();
2090 
2091  // A global is described by a structure
2092  // size_t beg;
2093  // size_t size;
2094  // size_t size_with_redzone;
2095  // const char *name;
2096  // const char *module_name;
2097  // size_t has_dynamic_init;
2098  // void *source_location;
2099  // size_t odr_indicator;
2100  // We initialize an array of such structures and pass it to a run-time call.
2101  StructType *GlobalStructTy =
2102  StructType::get(IntptrTy, IntptrTy, IntptrTy, IntptrTy, IntptrTy,
2103  IntptrTy, IntptrTy, IntptrTy);
2104  SmallVector<GlobalVariable *, 16> NewGlobals(n);
2105  SmallVector<Constant *, 16> Initializers(n);
2106 
2107  bool HasDynamicallyInitializedGlobals = false;
2108 
2109  // We shouldn't merge same module names, as this string serves as unique
2110  // module ID in runtime.
2112  M, M.getModuleIdentifier(), /*AllowMerging*/ false, kAsanGenPrefix);
2113 
2114  for (size_t i = 0; i < n; i++) {
2115  static const uint64_t kMaxGlobalRedzone = 1 << 18;
2116  GlobalVariable *G = GlobalsToChange[i];
2117 
2118  auto MD = GlobalsMD.get(G);
2119  StringRef NameForGlobal = G->getName();
2120  // Create string holding the global name (use global name from metadata
2121  // if it's available, otherwise just write the name of global variable).
2123  M, MD.Name.empty() ? NameForGlobal : MD.Name,
2124  /*AllowMerging*/ true, kAsanGenPrefix);
2125 
2126  Type *Ty = G->getValueType();
2127  uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
2128  uint64_t MinRZ = MinRedzoneSizeForGlobal();
2129  // MinRZ <= RZ <= kMaxGlobalRedzone
2130  // and trying to make RZ to be ~ 1/4 of SizeInBytes.
2131  uint64_t RZ = std::max(
2132  MinRZ, std::min(kMaxGlobalRedzone, (SizeInBytes / MinRZ / 4) * MinRZ));
2133  uint64_t RightRedzoneSize = RZ;
2134  // Round up to MinRZ
2135  if (SizeInBytes % MinRZ) RightRedzoneSize += MinRZ - (SizeInBytes % MinRZ);
2136  assert(((RightRedzoneSize + SizeInBytes) % MinRZ) == 0);
2137  Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
2138 
2139  StructType *NewTy = StructType::get(Ty, RightRedZoneTy);
2140  Constant *NewInitializer = ConstantStruct::get(
2141  NewTy, G->getInitializer(), Constant::getNullValue(RightRedZoneTy));
2142 
2143  // Create a new global variable with enough space for a redzone.
2144  GlobalValue::LinkageTypes Linkage = G->getLinkage();
2145  if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
2146  Linkage = GlobalValue::InternalLinkage;
2147  GlobalVariable *NewGlobal =
2148  new GlobalVariable(M, NewTy, G->isConstant(), Linkage, NewInitializer,
2149  "", G, G->getThreadLocalMode());
2150  NewGlobal->copyAttributesFrom(G);
2151  NewGlobal->setComdat(G->getComdat());
2152  NewGlobal->setAlignment(MinRZ);
2153  // Don't fold globals with redzones. ODR violation detector and redzone
2154  // poisoning implicitly creates a dependence on the global's address, so it
2155  // is no longer valid for it to be marked unnamed_addr.
2157 
2158  // Move null-terminated C strings to "__asan_cstring" section on Darwin.
2159  if (TargetTriple.isOSBinFormatMachO() && !G->hasSection() &&
2160  G->isConstant()) {
2161  auto Seq = dyn_cast<ConstantDataSequential>(G->getInitializer());
2162  if (Seq && Seq->isCString())
2163  NewGlobal->setSection("__TEXT,__asan_cstring,regular");
2164  }
2165 
2166  // Transfer the debug info. The payload starts at offset zero so we can
2167  // copy the debug info over as is.
2169  G->getDebugInfo(GVs);
2170  for (auto *GV : GVs)
2171  NewGlobal->addDebugInfo(GV);
2172 
2173  Value *Indices2[2];
2174  Indices2[0] = IRB.getInt32(0);
2175  Indices2[1] = IRB.getInt32(0);
2176 
2177  G->replaceAllUsesWith(
2178  ConstantExpr::getGetElementPtr(NewTy, NewGlobal, Indices2, true));
2179  NewGlobal->takeName(G);
2180  G->eraseFromParent();
2181  NewGlobals[i] = NewGlobal;
2182 
2183  Constant *SourceLoc;
2184  if (!MD.SourceLoc.empty()) {
2185  auto SourceLocGlobal = createPrivateGlobalForSourceLoc(M, MD.SourceLoc);
2186  SourceLoc = ConstantExpr::getPointerCast(SourceLocGlobal, IntptrTy);
2187  } else {
2188  SourceLoc = ConstantInt::get(IntptrTy, 0);
2189  }
2190 
2191  Constant *ODRIndicator = ConstantExpr::getNullValue(IRB.getInt8PtrTy());
2192  GlobalValue *InstrumentedGlobal = NewGlobal;
2193 
2194  bool CanUsePrivateAliases =
2195  TargetTriple.isOSBinFormatELF() || TargetTriple.isOSBinFormatMachO() ||
2196  TargetTriple.isOSBinFormatWasm();
2197  if (CanUsePrivateAliases && UsePrivateAlias) {
2198  // Create local alias for NewGlobal to avoid crash on ODR between
2199  // instrumented and non-instrumented libraries.
2200  InstrumentedGlobal =
2202  }
2203 
2204  // ODR should not happen for local linkage.
2205  if (NewGlobal->hasLocalLinkage()) {
2206  ODRIndicator = ConstantExpr::getIntToPtr(ConstantInt::get(IntptrTy, -1),
2207  IRB.getInt8PtrTy());
2208  } else if (UseOdrIndicator) {
2209  // With local aliases, we need to provide another externally visible
2210  // symbol __odr_asan_XXX to detect ODR violation.
2211  auto *ODRIndicatorSym =
2212  new GlobalVariable(M, IRB.getInt8Ty(), false, Linkage,
2214  kODRGenPrefix + NameForGlobal, nullptr,
2215  NewGlobal->getThreadLocalMode());
2216 
2217  // Set meaningful attributes for indicator symbol.
2218  ODRIndicatorSym->setVisibility(NewGlobal->getVisibility());
2219  ODRIndicatorSym->setDLLStorageClass(NewGlobal->getDLLStorageClass());
2220  ODRIndicatorSym->setAlignment(1);
2221  ODRIndicator = ODRIndicatorSym;
2222  }
2223 
2224  Constant *Initializer = ConstantStruct::get(
2225  GlobalStructTy,
2226  ConstantExpr::getPointerCast(InstrumentedGlobal, IntptrTy),
2227  ConstantInt::get(IntptrTy, SizeInBytes),
2228  ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
2229  ConstantExpr::getPointerCast(Name, IntptrTy),
2230  ConstantExpr::getPointerCast(ModuleName, IntptrTy),
2231  ConstantInt::get(IntptrTy, MD.IsDynInit), SourceLoc,
2232  ConstantExpr::getPointerCast(ODRIndicator, IntptrTy));
2233 
2234  if (ClInitializers && MD.IsDynInit) HasDynamicallyInitializedGlobals = true;
2235 
2236  LLVM_DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
2237 
2238  Initializers[i] = Initializer;
2239  }
2240 
2241  // Add instrumented globals to llvm.compiler.used list to avoid LTO from
2242  // ConstantMerge'ing them.
2243  SmallVector<GlobalValue *, 16> GlobalsToAddToUsedList;
2244  for (size_t i = 0; i < n; i++) {
2245  GlobalVariable *G = NewGlobals[i];
2246  if (G->getName().empty()) continue;
2247  GlobalsToAddToUsedList.push_back(G);
2248  }
2249  appendToCompilerUsed(M, ArrayRef<GlobalValue *>(GlobalsToAddToUsedList));
2250 
2251  std::string ELFUniqueModuleId =
2252  (UseGlobalsGC && TargetTriple.isOSBinFormatELF()) ? getUniqueModuleId(&M)
2253  : "";
2254 
2255  if (!ELFUniqueModuleId.empty()) {
2256  InstrumentGlobalsELF(IRB, M, NewGlobals, Initializers, ELFUniqueModuleId);
2257  *CtorComdat = true;
2258  } else if (UseGlobalsGC && TargetTriple.isOSBinFormatCOFF()) {
2259  InstrumentGlobalsCOFF(IRB, M, NewGlobals, Initializers);
2260  } else if (UseGlobalsGC && ShouldUseMachOGlobalsSection()) {
2261  InstrumentGlobalsMachO(IRB, M, NewGlobals, Initializers);
2262  } else {
2263  InstrumentGlobalsWithMetadataArray(IRB, M, NewGlobals, Initializers);
2264  }
2265 
2266  // Create calls for poisoning before initializers run and unpoisoning after.
2267  if (HasDynamicallyInitializedGlobals)
2268  createInitializerPoisonCalls(M, ModuleName);
2269 
2270  LLVM_DEBUG(dbgs() << M);
2271  return true;
2272 }
2273 
2274 int AddressSanitizerModule::GetAsanVersion(const Module &M) const {
2275  int LongSize = M.getDataLayout().getPointerSizeInBits();
2276  bool isAndroid = Triple(M.getTargetTriple()).isAndroid();
2277  int Version = 8;
2278  // 32-bit Android is one version ahead because of the switch to dynamic
2279  // shadow.
2280  Version += (LongSize == 32 && isAndroid);
2281  return Version;
2282 }
2283 
2284 bool AddressSanitizerModule::runOnModule(Module &M) {
2285  C = &(M.getContext());
2286  int LongSize = M.getDataLayout().getPointerSizeInBits();
2287  IntptrTy = Type::getIntNTy(*C, LongSize);
2288  TargetTriple = Triple(M.getTargetTriple());
2289  Mapping = getShadowMapping(TargetTriple, LongSize, CompileKernel);
2290  initializeCallbacks(M);
2291 
2292  if (CompileKernel)
2293  return false;
2294 
2295  // Create a module constructor. A destructor is created lazily because not all
2296  // platforms, and not all modules need it.
2297  std::string VersionCheckName =
2298  kAsanVersionCheckNamePrefix + std::to_string(GetAsanVersion(M));
2299  std::tie(AsanCtorFunction, std::ignore) = createSanitizerCtorAndInitFunctions(
2300  M, kAsanModuleCtorName, kAsanInitName, /*InitArgTypes=*/{},
2301  /*InitArgs=*/{}, VersionCheckName);
2302 
2303  bool CtorComdat = true;
2304  bool Changed = false;
2305  // TODO(glider): temporarily disabled globals instrumentation for KASan.
2306  if (ClGlobals) {
2307  IRBuilder<> IRB(AsanCtorFunction->getEntryBlock().getTerminator());
2308  Changed |= InstrumentGlobals(IRB, M, &CtorComdat);
2309  }
2310 
2311  // Put the constructor and destructor in comdat if both
2312  // (1) global instrumentation is not TU-specific
2313  // (2) target is ELF.
2314  if (UseCtorComdat && TargetTriple.isOSBinFormatELF() && CtorComdat) {
2315  AsanCtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleCtorName));
2316  appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndDtorPriority,
2317  AsanCtorFunction);
2318  if (AsanDtorFunction) {
2319  AsanDtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleDtorName));
2320  appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndDtorPriority,
2321  AsanDtorFunction);
2322  }
2323  } else {
2324  appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndDtorPriority);
2325  if (AsanDtorFunction)
2326  appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndDtorPriority);
2327  }
2328 
2329  return Changed;
2330 }
2331 
2332 void AddressSanitizer::initializeCallbacks(Module &M) {
2333  IRBuilder<> IRB(*C);
2334  // Create __asan_report* callbacks.
2335  // IsWrite, TypeSize and Exp are encoded in the function name.
2336  for (int Exp = 0; Exp < 2; Exp++) {
2337  for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
2338  const std::string TypeStr = AccessIsWrite ? "store" : "load";
2339  const std::string ExpStr = Exp ? "exp_" : "";
2340  const std::string EndingStr = Recover ? "_noabort" : "";
2341 
2342  SmallVector<Type *, 3> Args2 = {IntptrTy, IntptrTy};
2343  SmallVector<Type *, 2> Args1{1, IntptrTy};
2344  if (Exp) {
2345  Type *ExpType = Type::getInt32Ty(*C);
2346  Args2.push_back(ExpType);
2347  Args1.push_back(ExpType);
2348  }
2349  AsanErrorCallbackSized[AccessIsWrite][Exp] =
2351  kAsanReportErrorTemplate + ExpStr + TypeStr + "_n" + EndingStr,
2352  FunctionType::get(IRB.getVoidTy(), Args2, false)));
2353 
2354  AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] =
2356  ClMemoryAccessCallbackPrefix + ExpStr + TypeStr + "N" + EndingStr,
2357  FunctionType::get(IRB.getVoidTy(), Args2, false)));
2358 
2359  for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
2360  AccessSizeIndex++) {
2361  const std::string Suffix = TypeStr + itostr(1ULL << AccessSizeIndex);
2362  AsanErrorCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2364  kAsanReportErrorTemplate + ExpStr + Suffix + EndingStr,
2365  FunctionType::get(IRB.getVoidTy(), Args1, false)));
2366 
2367  AsanMemoryAccessCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2369  ClMemoryAccessCallbackPrefix + ExpStr + Suffix + EndingStr,
2370  FunctionType::get(IRB.getVoidTy(), Args1, false)));
2371  }
2372  }
2373  }
2374 
2375  const std::string MemIntrinCallbackPrefix =
2376  CompileKernel ? std::string("") : ClMemoryAccessCallbackPrefix;
2378  MemIntrinCallbackPrefix + "memmove", IRB.getInt8PtrTy(),
2379  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy));
2381  MemIntrinCallbackPrefix + "memcpy", IRB.getInt8PtrTy(),
2382  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy));
2384  MemIntrinCallbackPrefix + "memset", IRB.getInt8PtrTy(),
2385  IRB.getInt8PtrTy(), IRB.getInt32Ty(), IntptrTy));
2386 
2387  AsanHandleNoReturnFunc = checkSanitizerInterfaceFunction(
2388  M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy()));
2389 
2391  kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy));
2393  kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy));
2394  // We insert an empty inline asm after __asan_report* to avoid callback merge.
2395  EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
2396  StringRef(""), StringRef(""),
2397  /*hasSideEffects=*/true);
2398  if (Mapping.InGlobal)
2399  AsanShadowGlobal = M.getOrInsertGlobal("__asan_shadow",
2400  ArrayType::get(IRB.getInt8Ty(), 0));
2401 }
2402 
2403 // virtual
2404 bool AddressSanitizer::doInitialization(Module &M) {
2405  // Initialize the private fields. No one has accessed them before.
2406  GlobalsMD.init(M);
2407 
2408  C = &(M.getContext());
2409  LongSize = M.getDataLayout().getPointerSizeInBits();
2410  IntptrTy = Type::getIntNTy(*C, LongSize);
2411  TargetTriple = Triple(M.getTargetTriple());
2412 
2413  Mapping = getShadowMapping(TargetTriple, LongSize, CompileKernel);
2414  return true;
2415 }
2416 
2417 bool AddressSanitizer::doFinalization(Module &M) {
2418  GlobalsMD.reset();
2419  return false;
2420 }
2421 
2422 bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
2423  // For each NSObject descendant having a +load method, this method is invoked
2424  // by the ObjC runtime before any of the static constructors is called.
2425  // Therefore we need to instrument such methods with a call to __asan_init
2426  // at the beginning in order to initialize our runtime before any access to
2427  // the shadow memory.
2428  // We cannot just ignore these methods, because they may call other
2429  // instrumented functions.
2430  if (F.getName().find(" load]") != std::string::npos) {
2431  Function *AsanInitFunction =
2433  IRBuilder<> IRB(&F.front(), F.front().begin());
2434  IRB.CreateCall(AsanInitFunction, {});
2435  return true;
2436  }
2437  return false;
2438 }
2439 
2440 void AddressSanitizer::maybeInsertDynamicShadowAtFunctionEntry(Function &F) {
2441  // Generate code only when dynamic addressing is needed.
2442  if (Mapping.Offset != kDynamicShadowSentinel)
2443  return;
2444 
2445  IRBuilder<> IRB(&F.front().front());
2446  if (Mapping.InGlobal) {
2448  // An empty inline asm with input reg == output reg.
2449  // An opaque pointer-to-int cast, basically.
2451  FunctionType::get(IntptrTy, {AsanShadowGlobal->getType()}, false),
2452  StringRef(""), StringRef("=r,0"),
2453  /*hasSideEffects=*/false);
2454  LocalDynamicShadow =
2455  IRB.CreateCall(Asm, {AsanShadowGlobal}, ".asan.shadow");
2456  } else {
2457  LocalDynamicShadow =
2458  IRB.CreatePointerCast(AsanShadowGlobal, IntptrTy, ".asan.shadow");
2459  }
2460  } else {
2461  Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
2462  kAsanShadowMemoryDynamicAddress, IntptrTy);
2463  LocalDynamicShadow = IRB.CreateLoad(GlobalDynamicAddress);
2464  }
2465 }
2466 
2467 void AddressSanitizer::markEscapedLocalAllocas(Function &F) {
2468  // Find the one possible call to llvm.localescape and pre-mark allocas passed
2469  // to it as uninteresting. This assumes we haven't started processing allocas
2470  // yet. This check is done up front because iterating the use list in
2471  // isInterestingAlloca would be algorithmically slower.
2472  assert(ProcessedAllocas.empty() && "must process localescape before allocas");
2473 
2474  // Try to get the declaration of llvm.localescape. If it's not in the module,
2475  // we can exit early.
2476  if (!F.getParent()->getFunction("llvm.localescape")) return;
2477 
2478  // Look for a call to llvm.localescape call in the entry block. It can't be in
2479  // any other block.
2480  for (Instruction &I : F.getEntryBlock()) {
2482  if (II && II->getIntrinsicID() == Intrinsic::localescape) {
2483  // We found a call. Mark all the allocas passed in as uninteresting.
2484  for (Value *Arg : II->arg_operands()) {
2486  assert(AI && AI->isStaticAlloca() &&
2487  "non-static alloca arg to localescape");
2488  ProcessedAllocas[AI] = false;
2489  }
2490  break;
2491  }
2492  }
2493 }
2494 
2496  if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
2497  if (!ClDebugFunc.empty() && ClDebugFunc == F.getName()) return false;
2498  if (F.getName().startswith("__asan_")) return false;
2499 
2500  bool FunctionModified = false;
2501 
2502  // If needed, insert __asan_init before checking for SanitizeAddress attr.
2503  // This function needs to be called even if the function body is not
2504  // instrumented.
2505  if (maybeInsertAsanInitAtFunctionEntry(F))
2506  FunctionModified = true;
2507 
2508  // Leave if the function doesn't need instrumentation.
2509  if (!F.hasFnAttribute(Attribute::SanitizeAddress)) return FunctionModified;
2510 
2511  LLVM_DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
2512 
2513  initializeCallbacks(*F.getParent());
2514  DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
2515 
2516  FunctionStateRAII CleanupObj(this);
2517 
2518  maybeInsertDynamicShadowAtFunctionEntry(F);
2519 
2520  // We can't instrument allocas used with llvm.localescape. Only static allocas
2521  // can be passed to that intrinsic.
2522  markEscapedLocalAllocas(F);
2523 
2524  // We want to instrument every address only once per basic block (unless there
2525  // are calls between uses).
2526  SmallPtrSet<Value *, 16> TempsToInstrument;
2527  SmallVector<Instruction *, 16> ToInstrument;
2528  SmallVector<Instruction *, 8> NoReturnCalls;
2530  SmallVector<Instruction *, 16> PointerComparisonsOrSubtracts;
2531  int NumAllocas = 0;
2532  bool IsWrite;
2533  unsigned Alignment;
2534  uint64_t TypeSize;
2535  const TargetLibraryInfo *TLI =
2536  &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
2537 
2538  // Fill the set of memory operations to instrument.
2539  for (auto &BB : F) {
2540  AllBlocks.push_back(&BB);
2541  TempsToInstrument.clear();
2542  int NumInsnsPerBB = 0;
2543  for (auto &Inst : BB) {
2544  if (LooksLikeCodeInBug11395(&Inst)) return false;
2545  Value *MaybeMask = nullptr;
2546  if (Value *Addr = isInterestingMemoryAccess(&Inst, &IsWrite, &TypeSize,
2547  &Alignment, &MaybeMask)) {
2548  if (ClOpt && ClOptSameTemp) {
2549  // If we have a mask, skip instrumentation if we've already
2550  // instrumented the full object. But don't add to TempsToInstrument
2551  // because we might get another load/store with a different mask.
2552  if (MaybeMask) {
2553  if (TempsToInstrument.count(Addr))
2554  continue; // We've seen this (whole) temp in the current BB.
2555  } else {
2556  if (!TempsToInstrument.insert(Addr).second)
2557  continue; // We've seen this temp in the current BB.
2558  }
2559  }
2560  } else if (ClInvalidPointerPairs &&
2562  PointerComparisonsOrSubtracts.push_back(&Inst);
2563  continue;
2564  } else if (isa<MemIntrinsic>(Inst)) {
2565  // ok, take it.
2566  } else {
2567  if (isa<AllocaInst>(Inst)) NumAllocas++;
2568  CallSite CS(&Inst);
2569  if (CS) {
2570  // A call inside BB.
2571  TempsToInstrument.clear();
2572  if (CS.doesNotReturn()) NoReturnCalls.push_back(CS.getInstruction());
2573  }
2574  if (CallInst *CI = dyn_cast<CallInst>(&Inst))
2576  continue;
2577  }
2578  ToInstrument.push_back(&Inst);
2579  NumInsnsPerBB++;
2580  if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB) break;
2581  }
2582  }
2583 
2584  bool UseCalls =
2587  const DataLayout &DL = F.getParent()->getDataLayout();
2588  ObjectSizeOpts ObjSizeOpts;
2589  ObjSizeOpts.RoundToAlign = true;
2590  ObjectSizeOffsetVisitor ObjSizeVis(DL, TLI, F.getContext(), ObjSizeOpts);
2591 
2592  // Instrument.
2593  int NumInstrumented = 0;
2594  for (auto Inst : ToInstrument) {
2595  if (ClDebugMin < 0 || ClDebugMax < 0 ||
2596  (NumInstrumented >= ClDebugMin && NumInstrumented <= ClDebugMax)) {
2597  if (isInterestingMemoryAccess(Inst, &IsWrite, &TypeSize, &Alignment))
2598  instrumentMop(ObjSizeVis, Inst, UseCalls,
2599  F.getParent()->getDataLayout());
2600  else
2601  instrumentMemIntrinsic(cast<MemIntrinsic>(Inst));
2602  }
2603  NumInstrumented++;
2604  }
2605 
2606  FunctionStackPoisoner FSP(F, *this);
2607  bool ChangedStack = FSP.runOnFunction();
2608 
2609  // We must unpoison the stack before every NoReturn call (throw, _exit, etc).
2610  // See e.g. https://github.com/google/sanitizers/issues/37
2611  for (auto CI : NoReturnCalls) {
2612  IRBuilder<> IRB(CI);
2613  IRB.CreateCall(AsanHandleNoReturnFunc, {});
2614  }
2615 
2616  for (auto Inst : PointerComparisonsOrSubtracts) {
2617  instrumentPointerComparisonOrSubtraction(Inst);
2618  NumInstrumented++;
2619  }
2620 
2621  if (NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty())
2622  FunctionModified = true;
2623 
2624  LLVM_DEBUG(dbgs() << "ASAN done instrumenting: " << FunctionModified << " "
2625  << F << "\n");
2626 
2627  return FunctionModified;
2628 }
2629 
2630 // Workaround for bug 11395: we don't want to instrument stack in functions
2631 // with large assembly blobs (32-bit only), otherwise reg alloc may crash.
2632 // FIXME: remove once the bug 11395 is fixed.
2633 bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
2634  if (LongSize != 32) return false;
2635  CallInst *CI = dyn_cast<CallInst>(I);
2636  if (!CI || !CI->isInlineAsm()) return false;
2637  if (CI->getNumArgOperands() <= 5) return false;
2638  // We have inline assembly with quite a few arguments.
2639  return true;
2640 }
2641 
2642 void FunctionStackPoisoner::initializeCallbacks(Module &M) {
2643  IRBuilder<> IRB(*C);
2644  for (int i = 0; i <= kMaxAsanStackMallocSizeClass; i++) {
2645  std::string Suffix = itostr(i);
2646  AsanStackMallocFunc[i] = checkSanitizerInterfaceFunction(
2647  M.getOrInsertFunction(kAsanStackMallocNameTemplate + Suffix, IntptrTy,
2648  IntptrTy));
2649  AsanStackFreeFunc[i] = checkSanitizerInterfaceFunction(
2650  M.getOrInsertFunction(kAsanStackFreeNameTemplate + Suffix,
2651  IRB.getVoidTy(), IntptrTy, IntptrTy));
2652  }
2653  if (ASan.UseAfterScope) {
2654  AsanPoisonStackMemoryFunc = checkSanitizerInterfaceFunction(
2655  M.getOrInsertFunction(kAsanPoisonStackMemoryName, IRB.getVoidTy(),
2656  IntptrTy, IntptrTy));
2657  AsanUnpoisonStackMemoryFunc = checkSanitizerInterfaceFunction(
2658  M.getOrInsertFunction(kAsanUnpoisonStackMemoryName, IRB.getVoidTy(),
2659  IntptrTy, IntptrTy));
2660  }
2661 
2662  for (size_t Val : {0x00, 0xf1, 0xf2, 0xf3, 0xf5, 0xf8}) {
2663  std::ostringstream Name;
2664  Name << kAsanSetShadowPrefix;
2665  Name << std::setw(2) << std::setfill('0') << std::hex << Val;
2666  AsanSetShadowFunc[Val] =
2668  Name.str(), IRB.getVoidTy(), IntptrTy, IntptrTy));
2669  }
2670 
2671  AsanAllocaPoisonFunc = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
2672  kAsanAllocaPoison, IRB.getVoidTy(), IntptrTy, IntptrTy));
2673  AsanAllocasUnpoisonFunc =
2675  kAsanAllocasUnpoison, IRB.getVoidTy(), IntptrTy, IntptrTy));
2676 }
2677 
2678 void FunctionStackPoisoner::copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
2679  ArrayRef<uint8_t> ShadowBytes,
2680  size_t Begin, size_t End,
2681  IRBuilder<> &IRB,
2682  Value *ShadowBase) {
2683  if (Begin >= End)
2684  return;
2685 
2686  const size_t LargestStoreSizeInBytes =
2687  std::min<size_t>(sizeof(uint64_t), ASan.LongSize / 8);
2688 
2689  const bool IsLittleEndian = F.getParent()->getDataLayout().isLittleEndian();
2690 
2691  // Poison given range in shadow using larges store size with out leading and
2692  // trailing zeros in ShadowMask. Zeros never change, so they need neither
2693  // poisoning nor up-poisoning. Still we don't mind if some of them get into a
2694  // middle of a store.
2695  for (size_t i = Begin; i < End;) {
2696  if (!ShadowMask[i]) {
2697  assert(!ShadowBytes[i]);
2698  ++i;
2699  continue;
2700  }
2701 
2702  size_t StoreSizeInBytes = LargestStoreSizeInBytes;
2703  // Fit store size into the range.
2704  while (StoreSizeInBytes > End - i)
2705  StoreSizeInBytes /= 2;
2706 
2707  // Minimize store size by trimming trailing zeros.
2708  for (size_t j = StoreSizeInBytes - 1; j && !ShadowMask[i + j]; --j) {
2709  while (j <= StoreSizeInBytes / 2)
2710  StoreSizeInBytes /= 2;
2711  }
2712 
2713  uint64_t Val = 0;
2714  for (size_t j = 0; j < StoreSizeInBytes; j++) {
2715  if (IsLittleEndian)
2716  Val |= (uint64_t)ShadowBytes[i + j] << (8 * j);
2717  else
2718  Val = (Val << 8) | ShadowBytes[i + j];
2719  }
2720 
2721  Value *Ptr = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
2722  Value *Poison = IRB.getIntN(StoreSizeInBytes * 8, Val);
2723  IRB.CreateAlignedStore(
2724  Poison, IRB.CreateIntToPtr(Ptr, Poison->getType()->getPointerTo()), 1);
2725 
2726  i += StoreSizeInBytes;
2727  }
2728 }
2729 
2730 void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2731  ArrayRef<uint8_t> ShadowBytes,
2732  IRBuilder<> &IRB, Value *ShadowBase) {
2733  copyToShadow(ShadowMask, ShadowBytes, 0, ShadowMask.size(), IRB, ShadowBase);
2734 }
2735 
2736 void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2737  ArrayRef<uint8_t> ShadowBytes,
2738  size_t Begin, size_t End,
2739  IRBuilder<> &IRB, Value *ShadowBase) {
2740  assert(ShadowMask.size() == ShadowBytes.size());
2741  size_t Done = Begin;
2742  for (size_t i = Begin, j = Begin + 1; i < End; i = j++) {
2743  if (!ShadowMask[i]) {
2744  assert(!ShadowBytes[i]);
2745  continue;
2746  }
2747  uint8_t Val = ShadowBytes[i];
2748  if (!AsanSetShadowFunc[Val])
2749  continue;
2750 
2751  // Skip same values.
2752  for (; j < End && ShadowMask[j] && Val == ShadowBytes[j]; ++j) {
2753  }
2754 
2755  if (j - i >= ClMaxInlinePoisoningSize) {
2756  copyToShadowInline(ShadowMask, ShadowBytes, Done, i, IRB, ShadowBase);
2757  IRB.CreateCall(AsanSetShadowFunc[Val],
2758  {IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i)),
2759  ConstantInt::get(IntptrTy, j - i)});
2760  Done = j;
2761  }
2762  }
2763 
2764  copyToShadowInline(ShadowMask, ShadowBytes, Done, End, IRB, ShadowBase);
2765 }
2766 
2767 // Fake stack allocator (asan_fake_stack.h) has 11 size classes
2768 // for every power of 2 from kMinStackMallocSize to kMaxAsanStackMallocSizeClass
2769 static int StackMallocSizeClass(uint64_t LocalStackSize) {
2770  assert(LocalStackSize <= kMaxStackMallocSize);
2771  uint64_t MaxSize = kMinStackMallocSize;
2772  for (int i = 0;; i++, MaxSize *= 2)
2773  if (LocalStackSize <= MaxSize) return i;
2774  llvm_unreachable("impossible LocalStackSize");
2775 }
2776 
2777 void FunctionStackPoisoner::copyArgsPassedByValToAllocas() {
2778  Instruction *CopyInsertPoint = &F.front().front();
2779  if (CopyInsertPoint == ASan.LocalDynamicShadow) {
2780  // Insert after the dynamic shadow location is determined
2781  CopyInsertPoint = CopyInsertPoint->getNextNode();
2782  assert(CopyInsertPoint);
2783  }
2784  IRBuilder<> IRB(CopyInsertPoint);
2785  const DataLayout &DL = F.getParent()->getDataLayout();
2786  for (Argument &Arg : F.args()) {
2787  if (Arg.hasByValAttr()) {
2789  unsigned Align = Arg.getParamAlignment();
2790  if (Align == 0) Align = DL.getABITypeAlignment(Ty);
2791 
2792  AllocaInst *AI = IRB.CreateAlloca(
2793  Ty, nullptr,
2794  (Arg.hasName() ? Arg.getName() : "Arg" + Twine(Arg.getArgNo())) +
2795  ".byval");
2796  AI->setAlignment(Align);
2797  Arg.replaceAllUsesWith(AI);
2798 
2799  uint64_t AllocSize = DL.getTypeAllocSize(Ty);
2800  IRB.CreateMemCpy(AI, Align, &Arg, Align, AllocSize);
2801  }
2802  }
2803 }
2804 
2805 PHINode *FunctionStackPoisoner::createPHI(IRBuilder<> &IRB, Value *Cond,
2806  Value *ValueIfTrue,
2807  Instruction *ThenTerm,
2808  Value *ValueIfFalse) {
2809  PHINode *PHI = IRB.CreatePHI(IntptrTy, 2);
2810  BasicBlock *CondBlock = cast<Instruction>(Cond)->getParent();
2811  PHI->addIncoming(ValueIfFalse, CondBlock);
2812  BasicBlock *ThenBlock = ThenTerm->getParent();
2813  PHI->addIncoming(ValueIfTrue, ThenBlock);
2814  return PHI;
2815 }
2816 
2817 Value *FunctionStackPoisoner::createAllocaForLayout(
2818  IRBuilder<> &IRB, const ASanStackFrameLayout &L, bool Dynamic) {
2819  AllocaInst *Alloca;
2820  if (Dynamic) {
2821  Alloca = IRB.CreateAlloca(IRB.getInt8Ty(),
2823  "MyAlloca");
2824  } else {
2825  Alloca = IRB.CreateAlloca(ArrayType::get(IRB.getInt8Ty(), L.FrameSize),
2826  nullptr, "MyAlloca");
2827  assert(Alloca->isStaticAlloca());
2828  }
2829  assert((ClRealignStack & (ClRealignStack - 1)) == 0);
2830  size_t FrameAlignment = std::max(L.FrameAlignment, (size_t)ClRealignStack);
2831  Alloca->setAlignment(FrameAlignment);
2832  return IRB.CreatePointerCast(Alloca, IntptrTy);
2833 }
2834 
2835 void FunctionStackPoisoner::createDynamicAllocasInitStorage() {
2836  BasicBlock &FirstBB = *F.begin();
2837  IRBuilder<> IRB(dyn_cast<Instruction>(FirstBB.begin()));
2838  DynamicAllocaLayout = IRB.CreateAlloca(IntptrTy, nullptr);
2839  IRB.CreateStore(Constant::getNullValue(IntptrTy), DynamicAllocaLayout);
2840  DynamicAllocaLayout->setAlignment(32);
2841 }
2842 
2843 void FunctionStackPoisoner::processDynamicAllocas() {
2844  if (!ClInstrumentDynamicAllocas || DynamicAllocaVec.empty()) {
2845  assert(DynamicAllocaPoisonCallVec.empty());
2846  return;
2847  }
2848 
2849  // Insert poison calls for lifetime intrinsics for dynamic allocas.
2850  for (const auto &APC : DynamicAllocaPoisonCallVec) {
2851  assert(APC.InsBefore);
2852  assert(APC.AI);
2853  assert(ASan.isInterestingAlloca(*APC.AI));
2854  assert(!APC.AI->isStaticAlloca());
2855 
2856  IRBuilder<> IRB(APC.InsBefore);
2857  poisonAlloca(APC.AI, APC.Size, IRB, APC.DoPoison);
2858  // Dynamic allocas will be unpoisoned unconditionally below in
2859  // unpoisonDynamicAllocas.
2860  // Flag that we need unpoison static allocas.
2861  }
2862 
2863  // Handle dynamic allocas.
2864  createDynamicAllocasInitStorage();
2865  for (auto &AI : DynamicAllocaVec)
2866  handleDynamicAllocaCall(AI);
2867  unpoisonDynamicAllocas();
2868 }
2869 
2870 void FunctionStackPoisoner::processStaticAllocas() {
2871  if (AllocaVec.empty()) {
2872  assert(StaticAllocaPoisonCallVec.empty());
2873  return;
2874  }
2875 
2876  int StackMallocIdx = -1;
2877  DebugLoc EntryDebugLocation;
2878  if (auto SP = F.getSubprogram())
2879  EntryDebugLocation = DebugLoc::get(SP->getScopeLine(), 0, SP);
2880 
2881  Instruction *InsBefore = AllocaVec[0];
2882  IRBuilder<> IRB(InsBefore);
2883  IRB.SetCurrentDebugLocation(EntryDebugLocation);
2884 
2885  // Make sure non-instrumented allocas stay in the entry block. Otherwise,
2886  // debug info is broken, because only entry-block allocas are treated as
2887  // regular stack slots.
2888  auto InsBeforeB = InsBefore->getParent();
2889  assert(InsBeforeB == &F.getEntryBlock());
2890  for (auto *AI : StaticAllocasToMoveUp)
2891  if (AI->getParent() == InsBeforeB)
2892  AI->moveBefore(InsBefore);
2893 
2894  // If we have a call to llvm.localescape, keep it in the entry block.
2895  if (LocalEscapeCall) LocalEscapeCall->moveBefore(InsBefore);
2896 
2898  SVD.reserve(AllocaVec.size());
2899  for (AllocaInst *AI : AllocaVec) {
2901  ASan.getAllocaSizeInBytes(*AI),
2902  0,
2903  AI->getAlignment(),
2904  AI,
2905  0,
2906  0};
2907  SVD.push_back(D);
2908  }
2909 
2910  // Minimal header size (left redzone) is 4 pointers,
2911  // i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms.
2912  size_t Granularity = 1ULL << Mapping.Scale;
2913  size_t MinHeaderSize = std::max((size_t)ASan.LongSize / 2, Granularity);
2914  const ASanStackFrameLayout &L =
2915  ComputeASanStackFrameLayout(SVD, Granularity, MinHeaderSize);
2916 
2917  // Build AllocaToSVDMap for ASanStackVariableDescription lookup.
2919  for (auto &Desc : SVD)
2920  AllocaToSVDMap[Desc.AI] = &Desc;
2921 
2922  // Update SVD with information from lifetime intrinsics.
2923  for (const auto &APC : StaticAllocaPoisonCallVec) {
2924  assert(APC.InsBefore);
2925  assert(APC.AI);
2926  assert(ASan.isInterestingAlloca(*APC.AI));
2927  assert(APC.AI->isStaticAlloca());
2928 
2929  ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
2930  Desc.LifetimeSize = Desc.Size;
2931  if (const DILocation *FnLoc = EntryDebugLocation.get()) {
2932  if (const DILocation *LifetimeLoc = APC.InsBefore->getDebugLoc().get()) {
2933  if (LifetimeLoc->getFile() == FnLoc->getFile())
2934  if (unsigned Line = LifetimeLoc->getLine())
2935  Desc.Line = std::min(Desc.Line ? Desc.Line : Line, Line);
2936  }
2937  }
2938  }
2939 
2940  auto DescriptionString = ComputeASanStackFrameDescription(SVD);
2941  LLVM_DEBUG(dbgs() << DescriptionString << " --- " << L.FrameSize << "\n");
2942  uint64_t LocalStackSize = L.FrameSize;
2943  bool DoStackMalloc = ClUseAfterReturn && !ASan.CompileKernel &&
2944  LocalStackSize <= kMaxStackMallocSize;
2945  bool DoDynamicAlloca = ClDynamicAllocaStack;
2946  // Don't do dynamic alloca or stack malloc if:
2947  // 1) There is inline asm: too often it makes assumptions on which registers
2948  // are available.
2949  // 2) There is a returns_twice call (typically setjmp), which is
2950  // optimization-hostile, and doesn't play well with introduced indirect
2951  // register-relative calculation of local variable addresses.
2952  DoDynamicAlloca &= !HasNonEmptyInlineAsm && !HasReturnsTwiceCall;
2953  DoStackMalloc &= !HasNonEmptyInlineAsm && !HasReturnsTwiceCall;
2954 
2955  Value *StaticAlloca =
2956  DoDynamicAlloca ? nullptr : createAllocaForLayout(IRB, L, false);
2957 
2958  Value *FakeStack;
2959  Value *LocalStackBase;
2960  Value *LocalStackBaseAlloca;
2961  bool Deref;
2962 
2963  if (DoStackMalloc) {
2964  LocalStackBaseAlloca =
2965  IRB.CreateAlloca(IntptrTy, nullptr, "asan_local_stack_base");
2966  // void *FakeStack = __asan_option_detect_stack_use_after_return
2967  // ? __asan_stack_malloc_N(LocalStackSize)
2968  // : nullptr;
2969  // void *LocalStackBase = (FakeStack) ? FakeStack : alloca(LocalStackSize);
2970  Constant *OptionDetectUseAfterReturn = F.getParent()->getOrInsertGlobal(
2971  kAsanOptionDetectUseAfterReturn, IRB.getInt32Ty());
2972  Value *UseAfterReturnIsEnabled =
2973  IRB.CreateICmpNE(IRB.CreateLoad(OptionDetectUseAfterReturn),
2975  Instruction *Term =
2976  SplitBlockAndInsertIfThen(UseAfterReturnIsEnabled, InsBefore, false);
2977  IRBuilder<> IRBIf(Term);
2978  IRBIf.SetCurrentDebugLocation(EntryDebugLocation);
2979  StackMallocIdx = StackMallocSizeClass(LocalStackSize);
2980  assert(StackMallocIdx <= kMaxAsanStackMallocSizeClass);
2981  Value *FakeStackValue =
2982  IRBIf.CreateCall(AsanStackMallocFunc[StackMallocIdx],
2983  ConstantInt::get(IntptrTy, LocalStackSize));
2984  IRB.SetInsertPoint(InsBefore);
2985  IRB.SetCurrentDebugLocation(EntryDebugLocation);
2986  FakeStack = createPHI(IRB, UseAfterReturnIsEnabled, FakeStackValue, Term,
2987  ConstantInt::get(IntptrTy, 0));
2988 
2989  Value *NoFakeStack =
2990  IRB.CreateICmpEQ(FakeStack, Constant::getNullValue(IntptrTy));
2991  Term = SplitBlockAndInsertIfThen(NoFakeStack, InsBefore, false);
2992  IRBIf.SetInsertPoint(Term);
2993  IRBIf.SetCurrentDebugLocation(EntryDebugLocation);
2994  Value *AllocaValue =
2995  DoDynamicAlloca ? createAllocaForLayout(IRBIf, L, true) : StaticAlloca;
2996 
2997  IRB.SetInsertPoint(InsBefore);
2998  IRB.SetCurrentDebugLocation(EntryDebugLocation);
2999  LocalStackBase = createPHI(IRB, NoFakeStack, AllocaValue, Term, FakeStack);
3000  IRB.SetCurrentDebugLocation(EntryDebugLocation);
3001  IRB.CreateStore(LocalStackBase, LocalStackBaseAlloca);
3002  Deref = true;
3003  } else {
3004  // void *FakeStack = nullptr;
3005  // void *LocalStackBase = alloca(LocalStackSize);
3006  FakeStack = ConstantInt::get(IntptrTy, 0);
3007  LocalStackBase =
3008  DoDynamicAlloca ? createAllocaForLayout(IRB, L, true) : StaticAlloca;
3009  LocalStackBaseAlloca = LocalStackBase;
3010  Deref = false;
3011  }
3012 
3013  // Replace Alloca instructions with base+offset.
3014  for (const auto &Desc : SVD) {
3015  AllocaInst *AI = Desc.AI;
3016  replaceDbgDeclareForAlloca(AI, LocalStackBaseAlloca, DIB, Deref,
3017  Desc.Offset, DIExpression::NoDeref);
3018  Value *NewAllocaPtr = IRB.CreateIntToPtr(
3019  IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Desc.Offset)),
3020  AI->getType());
3021  AI->replaceAllUsesWith(NewAllocaPtr);
3022  }
3023 
3024  // The left-most redzone has enough space for at least 4 pointers.
3025  // Write the Magic value to redzone[0].
3026  Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
3028  BasePlus0);
3029  // Write the frame description constant to redzone[1].
3030  Value *BasePlus1 = IRB.CreateIntToPtr(
3031  IRB.CreateAdd(LocalStackBase,
3032  ConstantInt::get(IntptrTy, ASan.LongSize / 8)),
3033  IntptrPtrTy);
3034  GlobalVariable *StackDescriptionGlobal =
3035  createPrivateGlobalForString(*F.getParent(), DescriptionString,
3036  /*AllowMerging*/ true, kAsanGenPrefix);
3037  Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal, IntptrTy);
3038  IRB.CreateStore(Description, BasePlus1);
3039  // Write the PC to redzone[2].
3040  Value *BasePlus2 = IRB.CreateIntToPtr(
3041  IRB.CreateAdd(LocalStackBase,
3042  ConstantInt::get(IntptrTy, 2 * ASan.LongSize / 8)),
3043  IntptrPtrTy);
3044  IRB.CreateStore(IRB.CreatePointerCast(&F, IntptrTy), BasePlus2);
3045 
3046  const auto &ShadowAfterScope = GetShadowBytesAfterScope(SVD, L);
3047 
3048  // Poison the stack red zones at the entry.
3049  Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
3050  // As mask we must use most poisoned case: red zones and after scope.
3051  // As bytes we can use either the same or just red zones only.
3052  copyToShadow(ShadowAfterScope, ShadowAfterScope, IRB, ShadowBase);
3053 
3054  if (!StaticAllocaPoisonCallVec.empty()) {
3055  const auto &ShadowInScope = GetShadowBytes(SVD, L);
3056 
3057  // Poison static allocas near lifetime intrinsics.
3058  for (const auto &APC : StaticAllocaPoisonCallVec) {
3059  const ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3060  assert(Desc.Offset % L.Granularity == 0);
3061  size_t Begin = Desc.Offset / L.Granularity;
3062  size_t End = Begin + (APC.Size + L.Granularity - 1) / L.Granularity;
3063 
3064  IRBuilder<> IRB(APC.InsBefore);
3065  copyToShadow(ShadowAfterScope,
3066  APC.DoPoison ? ShadowAfterScope : ShadowInScope, Begin, End,
3067  IRB, ShadowBase);
3068  }
3069  }
3070 
3071  SmallVector<uint8_t, 64> ShadowClean(ShadowAfterScope.size(), 0);
3072  SmallVector<uint8_t, 64> ShadowAfterReturn;
3073 
3074  // (Un)poison the stack before all ret instructions.
3075  for (auto Ret : RetVec) {
3076  IRBuilder<> IRBRet(Ret);
3077  // Mark the current frame as retired.
3079  BasePlus0);
3080  if (DoStackMalloc) {
3081  assert(StackMallocIdx >= 0);
3082  // if FakeStack != 0 // LocalStackBase == FakeStack
3083  // // In use-after-return mode, poison the whole stack frame.
3084  // if StackMallocIdx <= 4
3085  // // For small sizes inline the whole thing:
3086  // memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
3087  // **SavedFlagPtr(FakeStack) = 0
3088  // else
3089  // __asan_stack_free_N(FakeStack, LocalStackSize)
3090  // else
3091  // <This is not a fake stack; unpoison the redzones>
3092  Value *Cmp =
3093  IRBRet.CreateICmpNE(FakeStack, Constant::getNullValue(IntptrTy));
3094  Instruction *ThenTerm, *ElseTerm;
3095  SplitBlockAndInsertIfThenElse(Cmp, Ret, &ThenTerm, &ElseTerm);
3096 
3097  IRBuilder<> IRBPoison(ThenTerm);
3098  if (StackMallocIdx <= 4) {
3099  int ClassSize = kMinStackMallocSize << StackMallocIdx;
3100  ShadowAfterReturn.resize(ClassSize / L.Granularity,
3102  copyToShadow(ShadowAfterReturn, ShadowAfterReturn, IRBPoison,
3103  ShadowBase);
3104  Value *SavedFlagPtrPtr = IRBPoison.CreateAdd(
3105  FakeStack,
3106  ConstantInt::get(IntptrTy, ClassSize - ASan.LongSize / 8));
3107  Value *SavedFlagPtr = IRBPoison.CreateLoad(
3108  IRBPoison.CreateIntToPtr(SavedFlagPtrPtr, IntptrPtrTy));
3109  IRBPoison.CreateStore(
3110  Constant::getNullValue(IRBPoison.getInt8Ty()),
3111  IRBPoison.CreateIntToPtr(SavedFlagPtr, IRBPoison.getInt8PtrTy()));
3112  } else {
3113  // For larger frames call __asan_stack_free_*.
3114  IRBPoison.CreateCall(
3115  AsanStackFreeFunc[StackMallocIdx],
3116  {FakeStack, ConstantInt::get(IntptrTy, LocalStackSize)});
3117  }
3118 
3119  IRBuilder<> IRBElse(ElseTerm);
3120  copyToShadow(ShadowAfterScope, ShadowClean, IRBElse, ShadowBase);
3121  } else {
3122  copyToShadow(ShadowAfterScope, ShadowClean, IRBRet, ShadowBase);
3123  }
3124  }
3125 
3126  // We are done. Remove the old unused alloca instructions.
3127  for (auto AI : AllocaVec) AI->eraseFromParent();
3128 }
3129 
3130 void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
3131  IRBuilder<> &IRB, bool DoPoison) {
3132  // For now just insert the call to ASan runtime.
3133  Value *AddrArg = IRB.CreatePointerCast(V, IntptrTy);
3134  Value *SizeArg = ConstantInt::get(IntptrTy, Size);
3135  IRB.CreateCall(
3136  DoPoison ? AsanPoisonStackMemoryFunc : AsanUnpoisonStackMemoryFunc,
3137  {AddrArg, SizeArg});
3138 }
3139 
3140 // Handling llvm.lifetime intrinsics for a given %alloca:
3141 // (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
3142 // (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
3143 // invalid accesses) and unpoison it for llvm.lifetime.start (the memory
3144 // could be poisoned by previous llvm.lifetime.end instruction, as the
3145 // variable may go in and out of scope several times, e.g. in loops).
3146 // (3) if we poisoned at least one %alloca in a function,
3147 // unpoison the whole stack frame at function exit.
3148 
3149 AllocaInst *FunctionStackPoisoner::findAllocaForValue(Value *V) {
3150  if (AllocaInst *AI = dyn_cast<AllocaInst>(V))
3151  // We're interested only in allocas we can handle.
3152  return ASan.isInterestingAlloca(*AI) ? AI : nullptr;
3153  // See if we've already calculated (or started to calculate) alloca for a
3154  // given value.
3155  AllocaForValueMapTy::iterator I = AllocaForValue.find(V);
3156  if (I != AllocaForValue.end()) return I->second;
3157  // Store 0 while we're calculating alloca for value V to avoid
3158  // infinite recursion if the value references itself.
3159  AllocaForValue[V] = nullptr;
3160  AllocaInst *Res = nullptr;
3161  if (CastInst *CI = dyn_cast<CastInst>(V))
3162  Res = findAllocaForValue(CI->getOperand(0));
3163  else if (PHINode *PN = dyn_cast<PHINode>(V)) {
3164  for (Value *IncValue : PN->incoming_values()) {
3165  // Allow self-referencing phi-nodes.
3166  if (IncValue == PN) continue;
3167  AllocaInst *IncValueAI = findAllocaForValue(IncValue);
3168  // AI for incoming values should exist and should all be equal.
3169  if (IncValueAI == nullptr || (Res != nullptr && IncValueAI != Res))
3170  return nullptr;
3171  Res = IncValueAI;
3172  }
3173  } else if (GetElementPtrInst *EP = dyn_cast<GetElementPtrInst>(V)) {
3174  Res = findAllocaForValue(EP->getPointerOperand());
3175  } else {
3176  LLVM_DEBUG(dbgs() << "Alloca search canceled on unknown instruction: " << *V
3177  << "\n");
3178  }
3179  if (Res) AllocaForValue[V] = Res;
3180  return Res;
3181 }
3182 
3183 void FunctionStackPoisoner::handleDynamicAllocaCall(AllocaInst *AI) {
3184  IRBuilder<> IRB(AI);
3185 
3186  const unsigned Align = std::max(kAllocaRzSize, AI->getAlignment());
3187  const uint64_t AllocaRedzoneMask = kAllocaRzSize - 1;
3188 
3189  Value *Zero = Constant::getNullValue(IntptrTy);
3190  Value *AllocaRzSize = ConstantInt::get(IntptrTy, kAllocaRzSize);
3191  Value *AllocaRzMask = ConstantInt::get(IntptrTy, AllocaRedzoneMask);
3192 
3193  // Since we need to extend alloca with additional memory to locate
3194  // redzones, and OldSize is number of allocated blocks with
3195  // ElementSize size, get allocated memory size in bytes by
3196  // OldSize * ElementSize.
3197  const unsigned ElementSize =
3199  Value *OldSize =
3200  IRB.CreateMul(IRB.CreateIntCast(AI->getArraySize(), IntptrTy, false),
3201  ConstantInt::get(IntptrTy, ElementSize));
3202 
3203  // PartialSize = OldSize % 32
3204  Value *PartialSize = IRB.CreateAnd(OldSize, AllocaRzMask);
3205 
3206  // Misalign = kAllocaRzSize - PartialSize;
3207  Value *Misalign = IRB.CreateSub(AllocaRzSize, PartialSize);
3208 
3209  // PartialPadding = Misalign != kAllocaRzSize ? Misalign : 0;
3210  Value *Cond = IRB.CreateICmpNE(Misalign, AllocaRzSize);
3211  Value *PartialPadding = IRB.CreateSelect(Cond, Misalign, Zero);
3212 
3213  // AdditionalChunkSize = Align + PartialPadding + kAllocaRzSize
3214  // Align is added to locate left redzone, PartialPadding for possible
3215  // partial redzone and kAllocaRzSize for right redzone respectively.
3216  Value *AdditionalChunkSize = IRB.CreateAdd(
3217  ConstantInt::get(IntptrTy, Align + kAllocaRzSize), PartialPadding);
3218 
3219  Value *NewSize = IRB.CreateAdd(OldSize, AdditionalChunkSize);
3220 
3221  // Insert new alloca with new NewSize and Align params.
3222  AllocaInst *NewAlloca = IRB.CreateAlloca(IRB.getInt8Ty(), NewSize);
3223  NewAlloca->setAlignment(Align);
3224 
3225  // NewAddress = Address + Align
3226  Value *NewAddress = IRB.CreateAdd(IRB.CreatePtrToInt(NewAlloca, IntptrTy),
3227  ConstantInt::get(IntptrTy, Align));
3228 
3229  // Insert __asan_alloca_poison call for new created alloca.
3230  IRB.CreateCall(AsanAllocaPoisonFunc, {NewAddress, OldSize});
3231 
3232  // Store the last alloca's address to DynamicAllocaLayout. We'll need this
3233  // for unpoisoning stuff.
3234  IRB.CreateStore(IRB.CreatePtrToInt(NewAlloca, IntptrTy), DynamicAllocaLayout);
3235 
3236  Value *NewAddressPtr = IRB.CreateIntToPtr(NewAddress, AI->getType());
3237 
3238  // Replace all uses of AddessReturnedByAlloca with NewAddressPtr.
3239  AI->replaceAllUsesWith(NewAddressPtr);
3240 
3241  // We are done. Erase old alloca from parent.
3242  AI->eraseFromParent();
3243 }
3244 
3245 // isSafeAccess returns true if Addr is always inbounds with respect to its
3246 // base object. For example, it is a field access or an array access with
3247 // constant inbounds index.
3248 bool AddressSanitizer::isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis,
3249  Value *Addr, uint64_t TypeSize) const {
3250  SizeOffsetType SizeOffset = ObjSizeVis.compute(Addr);
3251  if (!ObjSizeVis.bothKnown(SizeOffset)) return false;
3252  uint64_t Size = SizeOffset.first.getZExtValue();
3253  int64_t Offset = SizeOffset.second.getSExtValue();
3254  // Three checks are required to ensure safety:
3255  // . Offset >= 0 (since the offset is given from the base ptr)
3256  // . Size >= Offset (unsigned)
3257  // . Size - Offset >= NeededSize (unsigned)
3258  return Offset >= 0 && Size >= uint64_t(Offset) &&
3259  Size - uint64_t(Offset) >= TypeSize / 8;
3260 }
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:1267
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:427
const std::string & getTargetTriple() const
Get the target triple which is a string describing the target host.
Definition: Module.h:240
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:685
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:1344
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:1540
Function * checkSanitizerInterfaceFunction(Constant *FuncOrBitcast)
Value * CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1843
NodeTy * getNextNode()
Get the next node, or nullptr for the list tail.
Definition: ilist_node.h:289
bool hasPrivateLinkage() const
Definition: GlobalValue.h:435
const Constant * getInitializer() const
getInitializer - Return the initializer for this global variable.
This class represents lattice values for constants.
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:144
LoadInst * CreateLoad(Type *Ty, Value *Ptr, const char *Name)
Provided to resolve &#39;CreateLoad(Ty, Ptr, "...")&#39; correctly, instead of converting the string to &#39;bool...
Definition: IRBuilder.h:1357
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:65
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:1154
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:529
static CallInst * Create(FunctionType *Ty, Value *F, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
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 > ClUsePrivateAlias("asan-use-private-alias", cl::desc("Use private aliases for global variables"), cl::Hidden, cl::init(false))
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:630
static bool isInterestingPointerComparisonOrSubtraction(Instruction *I)
static const char *const kODRGenPrefix
static Constant * getIntToPtr(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1760
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:466
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:387
INITIALIZE_PASS_BEGIN(AddressSanitizer, "asan", "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false, false) INITIALIZE_PASS_END(AddressSanitizer
unsigned getPointerSizeInBits(unsigned AS=0) const
Layout pointer size, in bits FIXME: The defaults need to be removed once all of the backends/clients ...
Definition: DataLayout.h:363
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
static cl::opt< bool > ClUseAfterScope("asan-use-after-scope", cl::desc("Check stack-use-after-scope"), cl::Hidden, cl::init(false))
F(f)
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:495
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:692
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:983
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:265
StoreInst * CreateAlignedStore(Value *Val, Value *Ptr, unsigned Align, bool isVolatile=false)
Definition: IRBuilder.h:1430
iterator begin()
Instruction iterator methods.
Definition: BasicBlock.h:269
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
Value * getArgOperand(unsigned i) const
Definition: InstrTypes.h:1135
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:371
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:353
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:244
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:652
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:1014
void setName(const Twine &Name)
Change the name of the value.
Definition: Value.cpp:285
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:342
Type * getVoidTy()
Fetch the type representing void.
Definition: IRBuilder.h:380
StoreInst * CreateStore(Value *Val, Value *Ptr, bool isVolatile=false)
Definition: IRBuilder.h:1386
Value * CreateIntToPtr(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1727
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
ModulePass * createAddressSanitizerModulePass(bool CompileKernel=false, bool Recover=false, bool UseGlobalsGC=true, bool UseOdrIndicator=true)
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:574
static const char *const kSanCovGenPrefix
bool empty() const
Definition: Module.h:604
bool isSwiftError() const
Return true if this value is a swifterror value.
Definition: Value.cpp:726
ArchType getArch() const
getArch - Get the parsed architecture type of this triple.
Definition: Triple.h:290
static cl::opt< bool > ClUseOdrIndicator("asan-use-odr-indicator", cl::desc("Use odr indicators to improve ODR reporting"), cl::Hidden, cl::init(false))
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:252
static cl::opt< bool > ClOpt("asan-opt", cl::desc("Optimize instrumentation"), cl::Hidden, cl::init(true))
MDNode * getMetadata(unsigned KindID) const
Get the metadata of given kind attached to this Instruction.
Definition: Instruction.h:221
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
iterator_range< User::op_iterator > arg_operands()
Definition: InstrTypes.h:1127
Value * CreateSub(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1031
bool isiOS() const
Is this an iOS triple.
Definition: Triple.h:456
An instruction for storing to memory.
Definition: Instructions.h:321
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:429
bool isOSNetBSD() const
Definition: Triple.h:483
Debug location.
void takeName(Value *V)
Transfer the name from V to this value.
Definition: Value.cpp:291
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:1020
void SetInsertPoint(BasicBlock *TheBB)
This specifies that created instructions should be appended to the end of the specified block...
Definition: IRBuilder.h:127
static const uint64_t kDefaultShadowOffset32
Value * getOperand(unsigned i) const
Definition: User.h:170
ConstantInt * getIntN(unsigned N, uint64_t C)
Get a constant N-bit value, zero extended or truncated from a 64-bit value.
Definition: IRBuilder.h:318
static void instrumentMaskedLoadOrStore(AddressSanitizer *Pass, const DataLayout &DL, Type *IntptrTy, Value *Mask, Instruction *I, Value *Addr, unsigned Alignment, unsigned Granularity, uint32_t TypeSize, bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp)
Value * CreateOr(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1182
Constant * getAggregateElement(unsigned Elt) const
For aggregates (struct/array/vector) return the constant that corresponds to the specified element if...
Definition: Constants.cpp:335
Type * getScalarType() const
If this is a vector type, return the element type, otherwise return &#39;this&#39;.
Definition: Type.h:304
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:567
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:854
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:423
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".
* 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:217
void setDebugLoc(DebugLoc Loc)
Set the debug location information for this instruction.
Definition: Instruction.h:308
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:296
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
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:2021
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:281
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.
bool isLifetimeStartOrEnd() const
Return true if the instruction is a llvm.lifetime.start or llvm.lifetime.end marker.
static Type * getVoidTy(LLVMContext &C)
Definition: Type.cpp:161
bool isAndroidVersionLT(unsigned Major) const
Definition: Triple.h:639
bool isPS4CPU() const
Tests whether the target is the PS4 CPU.
Definition: Triple.h:624
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:1867
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:1044
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:1839
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:2041
static const uint64_t kMyriadShadowScale
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:484
const Value * stripPointerCasts() const
Strip off pointer casts, all-zero GEPs, and aliases.
Definition: Value.cpp:529
static cl::opt< bool > ClGlobals("asan-globals", cl::desc("Handle global objects"), cl::Hidden, cl::init(true))
static cl::opt< uint32_t > ClMaxInlinePoisoningSize("asan-max-inline-poisoning-size", cl::desc("Inline shadow poisoning for blocks up to the given size in bytes."), cl::Hidden, cl::init(64))
const Value * getArraySize() const
Get the number of elements allocated.
Definition: Instructions.h:93
std::pair< APInt, APInt > SizeOffsetType
size_t size() const
Definition: SmallVector.h:53
static wasm::ValType getType(const TargetRegisterClass *RC)
PointerType * getInt8PtrTy(unsigned AddrSpace=0)
Fetch the type representing a pointer to an 8-bit integer value.
Definition: IRBuilder.h:385
const std::string & getModuleIdentifier() const
Get the module identifier which is, essentially, the name of the module.
Definition: Module.h:210
MDNode * createBranchWeights(uint32_t TrueWeight, uint32_t FalseWeight)
Return metadata containing two branch weights.
Definition: MDBuilder.cpp:38
static const uint64_t kWindowsShadowOffset32
Value * GetUnderlyingObject(Value *V, const DataLayout &DL, unsigned MaxLookup=6)
This method strips off any GEP address adjustments and pointer casts from the specified value...
INITIALIZE_PASS_END(RegBankSelect, DEBUG_TYPE, "Assign register bank of generic virtual registers", false, false) RegBankSelect
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
void initializeAddressSanitizerPass(PassRegistry &)
Value * CreateMul(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1048
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
constexpr bool empty(const T &RangeOrContainer)
Test whether RangeOrContainer is empty. Similar to C++17 std::empty.
Definition: STLExtras.h:210
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:1969
Value * CreateGEP(Value *Ptr, ArrayRef< Value *> IdxList, const Twine &Name="")
Definition: IRBuilder.h:1458
static Constant * getPointerCast(Constant *C, Type *Ty)
Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant expression.
Definition: Constants.cpp:1587
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:1801
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:730
const DataFlowGraph & G
Definition: RDFGraph.cpp:211
bool isOSLinux() const
Tests whether the OS is Linux.
Definition: Triple.h:577
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:622
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
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:491
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:176
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:414
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:1778
bool hasComdat() const
Definition: GlobalObject.h:100
void setMetadata(unsigned KindID, MDNode *MD)
Set a particular kind of metadata attachment.
Definition: Metadata.cpp:1434
amdgpu Simplify well known AMD library false Value Value * Arg
static cl::opt< bool > ClSkipPromotableAllocas("asan-skip-promotable-allocas", cl::desc("Do not instrument promotable allocas"), cl::Hidden, cl::init(true))
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:436
bool isMIPS32() const
Tests whether the target is MIPS 32-bit (little and big endian).
Definition: Triple.h:680
static const uint64_t kMyriadMemorySize32
static cl::opt< int > ClDebugMin("asan-debug-min", cl::desc("Debug min inst"), cl::Hidden, cl::init(-1))
unsigned getNumArgOperands() const
Definition: InstrTypes.h:1133
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:311
bool isInlineAsm() const
Check if this call is an inline asm statement.
static const uint64_t kMIPS64_ShadowOffset64
Constant * getOrInsertGlobal(StringRef Name, Type *Ty, function_ref< GlobalVariable *()> CreateGlobalCallback)
Look up the specified global in the module symbol table.
Definition: Module.cpp:206
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:665
static int StackMallocSizeClass(uint64_t LocalStackSize)
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:56
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:214
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:581
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
static const uint64_t kNetBSDKasan_ShadowOffset64
Rename collisions when linking (static functions).
Definition: GlobalValue.h:56
void maybeMarkSanitizerLibraryCallNoBuiltin(CallInst *CI, const TargetLibraryInfo *TLI)
Given a CallInst, check if it calls a string function known to CodeGen, and mark it with NoBuiltin if...
Definition: Local.cpp:2823
CallInst * CreateCall(FunctionType *FTy, Value *Callee, ArrayRef< Value *> Args=None, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:1974
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:1164
Value * CreatePtrToInt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1722
const std::string to_string(const T &Value)
Definition: ScopedPrinter.h:62
static uint64_t getAllocaSizeInBytes(const AllocaInst &AI)
static const char *const kAsanUnregisterGlobalsName
iterator_range< df_iterator< T > > depth_first(const T &G)
static const char *const kAsanUnpoisonGlobalsName
bool isArrayAllocation() const
Return true if there is an allocation size parameter to the allocation instruction that is not 1...
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
const BasicBlock & front() const
Definition: Function.h:663
static bool bothKnown(const SizeOffsetType &SizeOffset)
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)
INITIALIZE_PASS(AddressSanitizerModule, "asan-module", "AddressSanitizer: detects use-after-free and out-of-bounds bugs." "ModulePass", false, false) ModulePass *llvm
static const uint64_t kPPC64_ShadowOffset64
static const unsigned kAllocaRzSize
bool hasInitializer() const
Definitions have initializers, declarations don&#39;t.
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:637
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:469
Value * CreateLShr(Value *LHS, Value *RHS, const Twine &Name="", bool isExact=false)
Definition: IRBuilder.h:1124
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:584
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
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
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:670
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
void resize(size_type N)
Definition: SmallVector.h:351