LLVM  9.0.0svn
AddressSanitizer.cpp
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1 //===- AddressSanitizer.cpp - memory error detector -----------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of AddressSanitizer, an address sanity checker.
10 // Details of the algorithm:
11 // https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm
12 //
13 //===----------------------------------------------------------------------===//
14 
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/SmallPtrSet.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/ADT/StringExtras.h"
23 #include "llvm/ADT/StringRef.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/ADT/Twine.h"
30 #include "llvm/IR/Argument.h"
31 #include "llvm/IR/Attributes.h"
32 #include "llvm/IR/BasicBlock.h"
33 #include "llvm/IR/CallSite.h"
34 #include "llvm/IR/Comdat.h"
35 #include "llvm/IR/Constant.h"
36 #include "llvm/IR/Constants.h"
37 #include "llvm/IR/DIBuilder.h"
38 #include "llvm/IR/DataLayout.h"
40 #include "llvm/IR/DebugLoc.h"
41 #include "llvm/IR/DerivedTypes.h"
42 #include "llvm/IR/Dominators.h"
43 #include "llvm/IR/Function.h"
44 #include "llvm/IR/GlobalAlias.h"
45 #include "llvm/IR/GlobalValue.h"
46 #include "llvm/IR/GlobalVariable.h"
47 #include "llvm/IR/IRBuilder.h"
48 #include "llvm/IR/InlineAsm.h"
49 #include "llvm/IR/InstVisitor.h"
50 #include "llvm/IR/InstrTypes.h"
51 #include "llvm/IR/Instruction.h"
52 #include "llvm/IR/Instructions.h"
53 #include "llvm/IR/IntrinsicInst.h"
54 #include "llvm/IR/Intrinsics.h"
55 #include "llvm/IR/LLVMContext.h"
56 #include "llvm/IR/MDBuilder.h"
57 #include "llvm/IR/Metadata.h"
58 #include "llvm/IR/Module.h"
59 #include "llvm/IR/Type.h"
60 #include "llvm/IR/Use.h"
61 #include "llvm/IR/Value.h"
62 #include "llvm/MC/MCSectionMachO.h"
63 #include "llvm/Pass.h"
64 #include "llvm/Support/Casting.h"
66 #include "llvm/Support/Debug.h"
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 /// This struct defines the shadow mapping using the rule:
397 /// shadow = (mem >> Scale) ADD-or-OR Offset.
398 /// If InGlobal is true, then
399 /// extern char __asan_shadow[];
400 /// shadow = (mem >> Scale) + &__asan_shadow
401 struct ShadowMapping {
402  int Scale;
403  uint64_t Offset;
404  bool OrShadowOffset;
405  bool InGlobal;
406 };
407 
408 } // end anonymous namespace
409 
410 static ShadowMapping getShadowMapping(Triple &TargetTriple, int LongSize,
411  bool IsKasan) {
412  bool IsAndroid = TargetTriple.isAndroid();
413  bool IsIOS = TargetTriple.isiOS() || TargetTriple.isWatchOS();
414  bool IsFreeBSD = TargetTriple.isOSFreeBSD();
415  bool IsNetBSD = TargetTriple.isOSNetBSD();
416  bool IsPS4CPU = TargetTriple.isPS4CPU();
417  bool IsLinux = TargetTriple.isOSLinux();
418  bool IsPPC64 = TargetTriple.getArch() == Triple::ppc64 ||
419  TargetTriple.getArch() == Triple::ppc64le;
420  bool IsSystemZ = TargetTriple.getArch() == Triple::systemz;
421  bool IsX86 = TargetTriple.getArch() == Triple::x86;
422  bool IsX86_64 = TargetTriple.getArch() == Triple::x86_64;
423  bool IsMIPS32 = TargetTriple.isMIPS32();
424  bool IsMIPS64 = TargetTriple.isMIPS64();
425  bool IsArmOrThumb = TargetTriple.isARM() || TargetTriple.isThumb();
426  bool IsAArch64 = TargetTriple.getArch() == Triple::aarch64;
427  bool IsWindows = TargetTriple.isOSWindows();
428  bool IsFuchsia = TargetTriple.isOSFuchsia();
429  bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
430 
431  ShadowMapping Mapping;
432 
433  Mapping.Scale = IsMyriad ? kMyriadShadowScale : kDefaultShadowScale;
434  if (ClMappingScale.getNumOccurrences() > 0) {
435  Mapping.Scale = ClMappingScale;
436  }
437 
438  if (LongSize == 32) {
439  if (IsAndroid)
440  Mapping.Offset = kDynamicShadowSentinel;
441  else if (IsMIPS32)
442  Mapping.Offset = kMIPS32_ShadowOffset32;
443  else if (IsFreeBSD)
444  Mapping.Offset = kFreeBSD_ShadowOffset32;
445  else if (IsNetBSD)
446  Mapping.Offset = kNetBSD_ShadowOffset32;
447  else if (IsIOS)
448  // If we're targeting iOS and x86, the binary is built for iOS simulator.
449  Mapping.Offset = IsX86 ? kIOSSimShadowOffset32 : kIOSShadowOffset32;
450  else if (IsWindows)
451  Mapping.Offset = kWindowsShadowOffset32;
452  else if (IsMyriad) {
453  uint64_t ShadowOffset = (kMyriadMemoryOffset32 + kMyriadMemorySize32 -
454  (kMyriadMemorySize32 >> Mapping.Scale));
455  Mapping.Offset = ShadowOffset - (kMyriadMemoryOffset32 >> Mapping.Scale);
456  }
457  else
458  Mapping.Offset = kDefaultShadowOffset32;
459  } else { // LongSize == 64
460  // Fuchsia is always PIE, which means that the beginning of the address
461  // space is always available.
462  if (IsFuchsia)
463  Mapping.Offset = 0;
464  else if (IsPPC64)
465  Mapping.Offset = kPPC64_ShadowOffset64;
466  else if (IsSystemZ)
467  Mapping.Offset = kSystemZ_ShadowOffset64;
468  else if (IsFreeBSD && !IsMIPS64)
469  Mapping.Offset = kFreeBSD_ShadowOffset64;
470  else if (IsNetBSD) {
471  if (IsKasan)
472  Mapping.Offset = kNetBSDKasan_ShadowOffset64;
473  else
474  Mapping.Offset = kNetBSD_ShadowOffset64;
475  } else if (IsPS4CPU)
476  Mapping.Offset = kPS4CPU_ShadowOffset64;
477  else if (IsLinux && IsX86_64) {
478  if (IsKasan)
479  Mapping.Offset = kLinuxKasan_ShadowOffset64;
480  else
481  Mapping.Offset = (kSmallX86_64ShadowOffsetBase &
482  (kSmallX86_64ShadowOffsetAlignMask << Mapping.Scale));
483  } else if (IsWindows && IsX86_64) {
484  Mapping.Offset = kWindowsShadowOffset64;
485  } else if (IsMIPS64)
486  Mapping.Offset = kMIPS64_ShadowOffset64;
487  else if (IsIOS)
488  // If we're targeting iOS and x86, the binary is built for iOS simulator.
489  // We are using dynamic shadow offset on the 64-bit devices.
490  Mapping.Offset =
492  else if (IsAArch64)
493  Mapping.Offset = kAArch64_ShadowOffset64;
494  else
495  Mapping.Offset = kDefaultShadowOffset64;
496  }
497 
498  if (ClForceDynamicShadow) {
499  Mapping.Offset = kDynamicShadowSentinel;
500  }
501 
502  if (ClMappingOffset.getNumOccurrences() > 0) {
503  Mapping.Offset = ClMappingOffset;
504  }
505 
506  // OR-ing shadow offset if more efficient (at least on x86) if the offset
507  // is a power of two, but on ppc64 we have to use add since the shadow
508  // offset is not necessary 1/8-th of the address space. On SystemZ,
509  // we could OR the constant in a single instruction, but it's more
510  // efficient to load it once and use indexed addressing.
511  Mapping.OrShadowOffset = !IsAArch64 && !IsPPC64 && !IsSystemZ && !IsPS4CPU &&
512  !(Mapping.Offset & (Mapping.Offset - 1)) &&
513  Mapping.Offset != kDynamicShadowSentinel;
514  bool IsAndroidWithIfuncSupport =
515  IsAndroid && !TargetTriple.isAndroidVersionLT(21);
516  Mapping.InGlobal = ClWithIfunc && IsAndroidWithIfuncSupport && IsArmOrThumb;
517 
518  return Mapping;
519 }
520 
521 static size_t RedzoneSizeForScale(int MappingScale) {
522  // Redzone used for stack and globals is at least 32 bytes.
523  // For scales 6 and 7, the redzone has to be 64 and 128 bytes respectively.
524  return std::max(32U, 1U << MappingScale);
525 }
526 
527 namespace {
528 
529 /// Module analysis for getting various metadata about the module.
530 class ASanGlobalsMetadataWrapperPass : public ModulePass {
531 public:
532  static char ID;
533 
534  ASanGlobalsMetadataWrapperPass() : ModulePass(ID) {
537  }
538 
539  bool runOnModule(Module &M) override {
540  GlobalsMD = GlobalsMetadata(M);
541  return false;
542  }
543 
544  StringRef getPassName() const override {
545  return "ASanGlobalsMetadataWrapperPass";
546  }
547 
548  void getAnalysisUsage(AnalysisUsage &AU) const override {
549  AU.setPreservesAll();
550  }
551 
552  GlobalsMetadata &getGlobalsMD() { return GlobalsMD; }
553 
554 private:
555  GlobalsMetadata GlobalsMD;
556 };
557 
559 
560 /// AddressSanitizer: instrument the code in module to find memory bugs.
561 struct AddressSanitizer {
562  AddressSanitizer(Module &M, GlobalsMetadata &GlobalsMD,
563  bool CompileKernel = false, bool Recover = false,
564  bool UseAfterScope = false)
565  : UseAfterScope(UseAfterScope || ClUseAfterScope), GlobalsMD(GlobalsMD) {
566  this->Recover = ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover;
567  this->CompileKernel =
568  ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan : CompileKernel;
569 
570  C = &(M.getContext());
571  LongSize = M.getDataLayout().getPointerSizeInBits();
572  IntptrTy = Type::getIntNTy(*C, LongSize);
573  TargetTriple = Triple(M.getTargetTriple());
574 
575  Mapping = getShadowMapping(TargetTriple, LongSize, this->CompileKernel);
576  }
577 
578  uint64_t getAllocaSizeInBytes(const AllocaInst &AI) const {
579  uint64_t ArraySize = 1;
580  if (AI.isArrayAllocation()) {
581  const ConstantInt *CI = dyn_cast<ConstantInt>(AI.getArraySize());
582  assert(CI && "non-constant array size");
583  ArraySize = CI->getZExtValue();
584  }
585  Type *Ty = AI.getAllocatedType();
586  uint64_t SizeInBytes =
588  return SizeInBytes * ArraySize;
589  }
590 
591  /// Check if we want (and can) handle this alloca.
592  bool isInterestingAlloca(const AllocaInst &AI);
593 
594  /// If it is an interesting memory access, return the PointerOperand
595  /// and set IsWrite/Alignment. Otherwise return nullptr.
596  /// MaybeMask is an output parameter for the mask Value, if we're looking at a
597  /// masked load/store.
598  Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite,
599  uint64_t *TypeSize, unsigned *Alignment,
600  Value **MaybeMask = nullptr);
601 
602  void instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis, Instruction *I,
603  bool UseCalls, const DataLayout &DL);
604  void instrumentPointerComparisonOrSubtraction(Instruction *I);
605  void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
606  Value *Addr, uint32_t TypeSize, bool IsWrite,
607  Value *SizeArgument, bool UseCalls, uint32_t Exp);
608  void instrumentUnusualSizeOrAlignment(Instruction *I,
609  Instruction *InsertBefore, Value *Addr,
610  uint32_t TypeSize, bool IsWrite,
611  Value *SizeArgument, bool UseCalls,
612  uint32_t Exp);
613  Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
614  Value *ShadowValue, uint32_t TypeSize);
615  Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
616  bool IsWrite, size_t AccessSizeIndex,
617  Value *SizeArgument, uint32_t Exp);
618  void instrumentMemIntrinsic(MemIntrinsic *MI);
619  Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
620  bool instrumentFunction(Function &F, const TargetLibraryInfo *TLI);
621  bool maybeInsertAsanInitAtFunctionEntry(Function &F);
622  void maybeInsertDynamicShadowAtFunctionEntry(Function &F);
623  void markEscapedLocalAllocas(Function &F);
624 
625 private:
626  friend struct FunctionStackPoisoner;
627 
628  void initializeCallbacks(Module &M);
629 
630  bool LooksLikeCodeInBug11395(Instruction *I);
631  bool GlobalIsLinkerInitialized(GlobalVariable *G);
632  bool isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis, Value *Addr,
633  uint64_t TypeSize) const;
634 
635  /// Helper to cleanup per-function state.
636  struct FunctionStateRAII {
638 
639  FunctionStateRAII(AddressSanitizer *Pass) : Pass(Pass) {
640  assert(Pass->ProcessedAllocas.empty() &&
641  "last pass forgot to clear cache");
642  assert(!Pass->LocalDynamicShadow);
643  }
644 
645  ~FunctionStateRAII() {
646  Pass->LocalDynamicShadow = nullptr;
647  Pass->ProcessedAllocas.clear();
648  }
649  };
650 
651  LLVMContext *C;
652  Triple TargetTriple;
653  int LongSize;
654  bool CompileKernel;
655  bool Recover;
656  bool UseAfterScope;
657  Type *IntptrTy;
658  ShadowMapping Mapping;
659  FunctionCallee AsanHandleNoReturnFunc;
660  FunctionCallee AsanPtrCmpFunction, AsanPtrSubFunction;
661  Constant *AsanShadowGlobal;
662 
663  // These arrays is indexed by AccessIsWrite, Experiment and log2(AccessSize).
664  FunctionCallee AsanErrorCallback[2][2][kNumberOfAccessSizes];
665  FunctionCallee AsanMemoryAccessCallback[2][2][kNumberOfAccessSizes];
666 
667  // These arrays is indexed by AccessIsWrite and Experiment.
668  FunctionCallee AsanErrorCallbackSized[2][2];
669  FunctionCallee AsanMemoryAccessCallbackSized[2][2];
670 
671  FunctionCallee AsanMemmove, AsanMemcpy, AsanMemset;
672  InlineAsm *EmptyAsm;
673  Value *LocalDynamicShadow = nullptr;
674  GlobalsMetadata GlobalsMD;
675  DenseMap<const AllocaInst *, bool> ProcessedAllocas;
676 };
677 
678 class AddressSanitizerLegacyPass : public FunctionPass {
679 public:
680  static char ID;
681 
682  explicit AddressSanitizerLegacyPass(bool CompileKernel = false,
683  bool Recover = false,
684  bool UseAfterScope = false)
685  : FunctionPass(ID), CompileKernel(CompileKernel), Recover(Recover),
686  UseAfterScope(UseAfterScope) {
688  }
689 
690  StringRef getPassName() const override {
691  return "AddressSanitizerFunctionPass";
692  }
693 
694  void getAnalysisUsage(AnalysisUsage &AU) const override {
695  AU.addRequired<ASanGlobalsMetadataWrapperPass>();
697  }
698 
699  bool runOnFunction(Function &F) override {
700  GlobalsMetadata &GlobalsMD =
701  getAnalysis<ASanGlobalsMetadataWrapperPass>().getGlobalsMD();
702  const TargetLibraryInfo *TLI =
703  &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
704  AddressSanitizer ASan(*F.getParent(), GlobalsMD, CompileKernel, Recover,
705  UseAfterScope);
706  return ASan.instrumentFunction(F, TLI);
707  }
708 
709 private:
710  bool CompileKernel;
711  bool Recover;
712  bool UseAfterScope;
713 };
714 
715 class ModuleAddressSanitizer {
716 public:
717  ModuleAddressSanitizer(Module &M, GlobalsMetadata &GlobalsMD,
718  bool CompileKernel = false, bool Recover = false,
719  bool UseGlobalsGC = true, bool UseOdrIndicator = false)
720  : GlobalsMD(GlobalsMD), UseGlobalsGC(UseGlobalsGC && ClUseGlobalsGC),
721  // Enable aliases as they should have no downside with ODR indicators.
722  UsePrivateAlias(UseOdrIndicator || ClUsePrivateAlias),
723  UseOdrIndicator(UseOdrIndicator || ClUseOdrIndicator),
724  // Not a typo: ClWithComdat is almost completely pointless without
725  // ClUseGlobalsGC (because then it only works on modules without
726  // globals, which are rare); it is a prerequisite for ClUseGlobalsGC;
727  // and both suffer from gold PR19002 for which UseGlobalsGC constructor
728  // argument is designed as workaround. Therefore, disable both
729  // ClWithComdat and ClUseGlobalsGC unless the frontend says it's ok to
730  // do globals-gc.
731  UseCtorComdat(UseGlobalsGC && ClWithComdat) {
732  this->Recover = ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover;
733  this->CompileKernel =
734  ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan : CompileKernel;
735 
736  C = &(M.getContext());
737  int LongSize = M.getDataLayout().getPointerSizeInBits();
738  IntptrTy = Type::getIntNTy(*C, LongSize);
739  TargetTriple = Triple(M.getTargetTriple());
740  Mapping = getShadowMapping(TargetTriple, LongSize, this->CompileKernel);
741  }
742 
743  bool instrumentModule(Module &);
744 
745 private:
746  void initializeCallbacks(Module &M);
747 
748  bool InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat);
749  void InstrumentGlobalsCOFF(IRBuilder<> &IRB, Module &M,
750  ArrayRef<GlobalVariable *> ExtendedGlobals,
751  ArrayRef<Constant *> MetadataInitializers);
752  void InstrumentGlobalsELF(IRBuilder<> &IRB, Module &M,
753  ArrayRef<GlobalVariable *> ExtendedGlobals,
754  ArrayRef<Constant *> MetadataInitializers,
755  const std::string &UniqueModuleId);
756  void InstrumentGlobalsMachO(IRBuilder<> &IRB, Module &M,
757  ArrayRef<GlobalVariable *> ExtendedGlobals,
758  ArrayRef<Constant *> MetadataInitializers);
759  void
760  InstrumentGlobalsWithMetadataArray(IRBuilder<> &IRB, Module &M,
761  ArrayRef<GlobalVariable *> ExtendedGlobals,
762  ArrayRef<Constant *> MetadataInitializers);
763 
764  GlobalVariable *CreateMetadataGlobal(Module &M, Constant *Initializer,
765  StringRef OriginalName);
766  void SetComdatForGlobalMetadata(GlobalVariable *G, GlobalVariable *Metadata,
767  StringRef InternalSuffix);
768  IRBuilder<> CreateAsanModuleDtor(Module &M);
769 
770  bool ShouldInstrumentGlobal(GlobalVariable *G);
771  bool ShouldUseMachOGlobalsSection() const;
772  StringRef getGlobalMetadataSection() const;
773  void poisonOneInitializer(Function &GlobalInit, GlobalValue *ModuleName);
774  void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
775  size_t MinRedzoneSizeForGlobal() const {
776  return RedzoneSizeForScale(Mapping.Scale);
777  }
778  int GetAsanVersion(const Module &M) const;
779 
780  GlobalsMetadata GlobalsMD;
781  bool CompileKernel;
782  bool Recover;
783  bool UseGlobalsGC;
784  bool UsePrivateAlias;
785  bool UseOdrIndicator;
786  bool UseCtorComdat;
787  Type *IntptrTy;
788  LLVMContext *C;
789  Triple TargetTriple;
790  ShadowMapping Mapping;
791  FunctionCallee AsanPoisonGlobals;
792  FunctionCallee AsanUnpoisonGlobals;
793  FunctionCallee AsanRegisterGlobals;
794  FunctionCallee AsanUnregisterGlobals;
795  FunctionCallee AsanRegisterImageGlobals;
796  FunctionCallee AsanUnregisterImageGlobals;
797  FunctionCallee AsanRegisterElfGlobals;
798  FunctionCallee AsanUnregisterElfGlobals;
799 
800  Function *AsanCtorFunction = nullptr;
801  Function *AsanDtorFunction = nullptr;
802 };
803 
804 class ModuleAddressSanitizerLegacyPass : public ModulePass {
805 public:
806  static char ID;
807 
808  explicit ModuleAddressSanitizerLegacyPass(bool CompileKernel = false,
809  bool Recover = false,
810  bool UseGlobalGC = true,
811  bool UseOdrIndicator = false)
812  : ModulePass(ID), CompileKernel(CompileKernel), Recover(Recover),
813  UseGlobalGC(UseGlobalGC), UseOdrIndicator(UseOdrIndicator) {
816  }
817 
818  StringRef getPassName() const override { return "ModuleAddressSanitizer"; }
819 
820  void getAnalysisUsage(AnalysisUsage &AU) const override {
821  AU.addRequired<ASanGlobalsMetadataWrapperPass>();
822  }
823 
824  bool runOnModule(Module &M) override {
825  GlobalsMetadata &GlobalsMD =
826  getAnalysis<ASanGlobalsMetadataWrapperPass>().getGlobalsMD();
827  ModuleAddressSanitizer ASanModule(M, GlobalsMD, CompileKernel, Recover,
828  UseGlobalGC, UseOdrIndicator);
829  return ASanModule.instrumentModule(M);
830  }
831 
832 private:
833  bool CompileKernel;
834  bool Recover;
835  bool UseGlobalGC;
836  bool UseOdrIndicator;
837 };
838 
839 // Stack poisoning does not play well with exception handling.
840 // When an exception is thrown, we essentially bypass the code
841 // that unpoisones the stack. This is why the run-time library has
842 // to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
843 // stack in the interceptor. This however does not work inside the
844 // actual function which catches the exception. Most likely because the
845 // compiler hoists the load of the shadow value somewhere too high.
846 // This causes asan to report a non-existing bug on 453.povray.
847 // It sounds like an LLVM bug.
848 struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
849  Function &F;
850  AddressSanitizer &ASan;
851  DIBuilder DIB;
852  LLVMContext *C;
853  Type *IntptrTy;
854  Type *IntptrPtrTy;
855  ShadowMapping Mapping;
856 
858  SmallVector<AllocaInst *, 16> StaticAllocasToMoveUp;
860  unsigned StackAlignment;
861 
862  FunctionCallee AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
863  AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
864  FunctionCallee AsanSetShadowFunc[0x100] = {};
865  FunctionCallee AsanPoisonStackMemoryFunc, AsanUnpoisonStackMemoryFunc;
866  FunctionCallee AsanAllocaPoisonFunc, AsanAllocasUnpoisonFunc;
867 
868  // Stores a place and arguments of poisoning/unpoisoning call for alloca.
869  struct AllocaPoisonCall {
870  IntrinsicInst *InsBefore;
871  AllocaInst *AI;
872  uint64_t Size;
873  bool DoPoison;
874  };
875  SmallVector<AllocaPoisonCall, 8> DynamicAllocaPoisonCallVec;
876  SmallVector<AllocaPoisonCall, 8> StaticAllocaPoisonCallVec;
877 
878  SmallVector<AllocaInst *, 1> DynamicAllocaVec;
879  SmallVector<IntrinsicInst *, 1> StackRestoreVec;
880  AllocaInst *DynamicAllocaLayout = nullptr;
881  IntrinsicInst *LocalEscapeCall = nullptr;
882 
883  // Maps Value to an AllocaInst from which the Value is originated.
884  using AllocaForValueMapTy = DenseMap<Value *, AllocaInst *>;
885  AllocaForValueMapTy AllocaForValue;
886 
887  bool HasNonEmptyInlineAsm = false;
888  bool HasReturnsTwiceCall = false;
889  std::unique_ptr<CallInst> EmptyInlineAsm;
890 
891  FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
892  : F(F), ASan(ASan), DIB(*F.getParent(), /*AllowUnresolved*/ false),
893  C(ASan.C), IntptrTy(ASan.IntptrTy),
894  IntptrPtrTy(PointerType::get(IntptrTy, 0)), Mapping(ASan.Mapping),
895  StackAlignment(1 << Mapping.Scale),
896  EmptyInlineAsm(CallInst::Create(ASan.EmptyAsm)) {}
897 
898  bool runOnFunction() {
899  if (!ClStack) return false;
900 
901  if (ClRedzoneByvalArgs)
902  copyArgsPassedByValToAllocas();
903 
904  // Collect alloca, ret, lifetime instructions etc.
905  for (BasicBlock *BB : depth_first(&F.getEntryBlock())) visit(*BB);
906 
907  if (AllocaVec.empty() && DynamicAllocaVec.empty()) return false;
908 
909  initializeCallbacks(*F.getParent());
910 
911  processDynamicAllocas();
912  processStaticAllocas();
913 
914  if (ClDebugStack) {
915  LLVM_DEBUG(dbgs() << F);
916  }
917  return true;
918  }
919 
920  // Arguments marked with the "byval" attribute are implicitly copied without
921  // using an alloca instruction. To produce redzones for those arguments, we
922  // copy them a second time into memory allocated with an alloca instruction.
923  void copyArgsPassedByValToAllocas();
924 
925  // Finds all Alloca instructions and puts
926  // poisoned red zones around all of them.
927  // Then unpoison everything back before the function returns.
928  void processStaticAllocas();
929  void processDynamicAllocas();
930 
931  void createDynamicAllocasInitStorage();
932 
933  // ----------------------- Visitors.
934  /// Collect all Ret instructions.
935  void visitReturnInst(ReturnInst &RI) { RetVec.push_back(&RI); }
936 
937  /// Collect all Resume instructions.
938  void visitResumeInst(ResumeInst &RI) { RetVec.push_back(&RI); }
939 
940  /// Collect all CatchReturnInst instructions.
941  void visitCleanupReturnInst(CleanupReturnInst &CRI) { RetVec.push_back(&CRI); }
942 
943  void unpoisonDynamicAllocasBeforeInst(Instruction *InstBefore,
944  Value *SavedStack) {
945  IRBuilder<> IRB(InstBefore);
946  Value *DynamicAreaPtr = IRB.CreatePtrToInt(SavedStack, IntptrTy);
947  // When we insert _asan_allocas_unpoison before @llvm.stackrestore, we
948  // need to adjust extracted SP to compute the address of the most recent
949  // alloca. We have a special @llvm.get.dynamic.area.offset intrinsic for
950  // this purpose.
951  if (!isa<ReturnInst>(InstBefore)) {
952  Function *DynamicAreaOffsetFunc = Intrinsic::getDeclaration(
953  InstBefore->getModule(), Intrinsic::get_dynamic_area_offset,
954  {IntptrTy});
955 
956  Value *DynamicAreaOffset = IRB.CreateCall(DynamicAreaOffsetFunc, {});
957 
958  DynamicAreaPtr = IRB.CreateAdd(IRB.CreatePtrToInt(SavedStack, IntptrTy),
959  DynamicAreaOffset);
960  }
961 
962  IRB.CreateCall(
963  AsanAllocasUnpoisonFunc,
964  {IRB.CreateLoad(IntptrTy, DynamicAllocaLayout), DynamicAreaPtr});
965  }
966 
967  // Unpoison dynamic allocas redzones.
968  void unpoisonDynamicAllocas() {
969  for (auto &Ret : RetVec)
970  unpoisonDynamicAllocasBeforeInst(Ret, DynamicAllocaLayout);
971 
972  for (auto &StackRestoreInst : StackRestoreVec)
973  unpoisonDynamicAllocasBeforeInst(StackRestoreInst,
974  StackRestoreInst->getOperand(0));
975  }
976 
977  // Deploy and poison redzones around dynamic alloca call. To do this, we
978  // should replace this call with another one with changed parameters and
979  // replace all its uses with new address, so
980  // addr = alloca type, old_size, align
981  // is replaced by
982  // new_size = (old_size + additional_size) * sizeof(type)
983  // tmp = alloca i8, new_size, max(align, 32)
984  // addr = tmp + 32 (first 32 bytes are for the left redzone).
985  // Additional_size is added to make new memory allocation contain not only
986  // requested memory, but also left, partial and right redzones.
987  void handleDynamicAllocaCall(AllocaInst *AI);
988 
989  /// Collect Alloca instructions we want (and can) handle.
990  void visitAllocaInst(AllocaInst &AI) {
991  if (!ASan.isInterestingAlloca(AI)) {
992  if (AI.isStaticAlloca()) {
993  // Skip over allocas that are present *before* the first instrumented
994  // alloca, we don't want to move those around.
995  if (AllocaVec.empty())
996  return;
997 
998  StaticAllocasToMoveUp.push_back(&AI);
999  }
1000  return;
1001  }
1002 
1003  StackAlignment = std::max(StackAlignment, AI.getAlignment());
1004  if (!AI.isStaticAlloca())
1005  DynamicAllocaVec.push_back(&AI);
1006  else
1007  AllocaVec.push_back(&AI);
1008  }
1009 
1010  /// Collect lifetime intrinsic calls to check for use-after-scope
1011  /// errors.
1012  void visitIntrinsicInst(IntrinsicInst &II) {
1014  if (ID == Intrinsic::stackrestore) StackRestoreVec.push_back(&II);
1015  if (ID == Intrinsic::localescape) LocalEscapeCall = &II;
1016  if (!ASan.UseAfterScope)
1017  return;
1018  if (!II.isLifetimeStartOrEnd())
1019  return;
1020  // Found lifetime intrinsic, add ASan instrumentation if necessary.
1022  // If size argument is undefined, don't do anything.
1023  if (Size->isMinusOne()) return;
1024  // Check that size doesn't saturate uint64_t and can
1025  // be stored in IntptrTy.
1026  const uint64_t SizeValue = Size->getValue().getLimitedValue();
1027  if (SizeValue == ~0ULL ||
1028  !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
1029  return;
1030  // Find alloca instruction that corresponds to llvm.lifetime argument.
1031  AllocaInst *AI = findAllocaForValue(II.getArgOperand(1));
1032  if (!AI || !ASan.isInterestingAlloca(*AI))
1033  return;
1034  bool DoPoison = (ID == Intrinsic::lifetime_end);
1035  AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
1036  if (AI->isStaticAlloca())
1037  StaticAllocaPoisonCallVec.push_back(APC);
1038  else if (ClInstrumentDynamicAllocas)
1039  DynamicAllocaPoisonCallVec.push_back(APC);
1040  }
1041 
1042  void visitCallSite(CallSite CS) {
1043  Instruction *I = CS.getInstruction();
1044  if (CallInst *CI = dyn_cast<CallInst>(I)) {
1045  HasNonEmptyInlineAsm |= CI->isInlineAsm() &&
1046  !CI->isIdenticalTo(EmptyInlineAsm.get()) &&
1047  I != ASan.LocalDynamicShadow;
1048  HasReturnsTwiceCall |= CI->canReturnTwice();
1049  }
1050  }
1051 
1052  // ---------------------- Helpers.
1053  void initializeCallbacks(Module &M);
1054 
1055  /// Finds alloca where the value comes from.
1056  AllocaInst *findAllocaForValue(Value *V);
1057 
1058  // Copies bytes from ShadowBytes into shadow memory for indexes where
1059  // ShadowMask is not zero. If ShadowMask[i] is zero, we assume that
1060  // ShadowBytes[i] is constantly zero and doesn't need to be overwritten.
1061  void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1062  IRBuilder<> &IRB, Value *ShadowBase);
1063  void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1064  size_t Begin, size_t End, IRBuilder<> &IRB,
1065  Value *ShadowBase);
1066  void copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
1067  ArrayRef<uint8_t> ShadowBytes, size_t Begin,
1068  size_t End, IRBuilder<> &IRB, Value *ShadowBase);
1069 
1070  void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
1071 
1072  Value *createAllocaForLayout(IRBuilder<> &IRB, const ASanStackFrameLayout &L,
1073  bool Dynamic);
1074  PHINode *createPHI(IRBuilder<> &IRB, Value *Cond, Value *ValueIfTrue,
1075  Instruction *ThenTerm, Value *ValueIfFalse);
1076 };
1077 
1078 } // end anonymous namespace
1079 
1081  assert(MDN->getNumOperands() == 3);
1082  MDString *DIFilename = cast<MDString>(MDN->getOperand(0));
1083  Filename = DIFilename->getString();
1084  LineNo = mdconst::extract<ConstantInt>(MDN->getOperand(1))->getLimitedValue();
1085  ColumnNo =
1086  mdconst::extract<ConstantInt>(MDN->getOperand(2))->getLimitedValue();
1087 }
1088 
1089 // FIXME: It would be cleaner to instead attach relevant metadata to the globals
1090 // we want to sanitize instead and reading this metadata on each pass over a
1091 // function instead of reading module level metadata at first.
1093  NamedMDNode *Globals = M.getNamedMetadata("llvm.asan.globals");
1094  if (!Globals)
1095  return;
1096  for (auto MDN : Globals->operands()) {
1097  // Metadata node contains the global and the fields of "Entry".
1098  assert(MDN->getNumOperands() == 5);
1099  auto *V = mdconst::extract_or_null<Constant>(MDN->getOperand(0));
1100  // The optimizer may optimize away a global entirely.
1101  if (!V)
1102  continue;
1103  auto *StrippedV = V->stripPointerCasts();
1104  auto *GV = dyn_cast<GlobalVariable>(StrippedV);
1105  if (!GV)
1106  continue;
1107  // We can already have an entry for GV if it was merged with another
1108  // global.
1109  Entry &E = Entries[GV];
1110  if (auto *Loc = cast_or_null<MDNode>(MDN->getOperand(1)))
1111  E.SourceLoc.parse(Loc);
1112  if (auto *Name = cast_or_null<MDString>(MDN->getOperand(2)))
1113  E.Name = Name->getString();
1114  ConstantInt *IsDynInit = mdconst::extract<ConstantInt>(MDN->getOperand(3));
1115  E.IsDynInit |= IsDynInit->isOne();
1116  ConstantInt *IsBlacklisted =
1117  mdconst::extract<ConstantInt>(MDN->getOperand(4));
1118  E.IsBlacklisted |= IsBlacklisted->isOne();
1119  }
1120 }
1121 
1122 AnalysisKey ASanGlobalsMetadataAnalysis::Key;
1123 
1125  ModuleAnalysisManager &AM) {
1126  return GlobalsMetadata(M);
1127 }
1128 
1129 AddressSanitizerPass::AddressSanitizerPass(bool CompileKernel, bool Recover,
1130  bool UseAfterScope)
1131  : CompileKernel(CompileKernel), Recover(Recover),
1132  UseAfterScope(UseAfterScope) {}
1133 
1136  auto &MAMProxy = AM.getResult<ModuleAnalysisManagerFunctionProxy>(F);
1137  auto &MAM = MAMProxy.getManager();
1138  Module &M = *F.getParent();
1139  if (auto *R = MAM.getCachedResult<ASanGlobalsMetadataAnalysis>(M)) {
1141  AddressSanitizer Sanitizer(M, *R, CompileKernel, Recover, UseAfterScope);
1142  if (Sanitizer.instrumentFunction(F, TLI))
1143  return PreservedAnalyses::none();
1144  return PreservedAnalyses::all();
1145  }
1146 
1148  "The ASanGlobalsMetadataAnalysis is required to run before "
1149  "AddressSanitizer can run");
1150  return PreservedAnalyses::all();
1151 }
1152 
1154  bool Recover,
1155  bool UseGlobalGC,
1156  bool UseOdrIndicator)
1157  : CompileKernel(CompileKernel), Recover(Recover), UseGlobalGC(UseGlobalGC),
1158  UseOdrIndicator(UseOdrIndicator) {}
1159 
1163  ModuleAddressSanitizer Sanitizer(M, GlobalsMD, CompileKernel, Recover,
1164  UseGlobalGC, UseOdrIndicator);
1165  if (Sanitizer.instrumentModule(M))
1166  return PreservedAnalyses::none();
1167  return PreservedAnalyses::all();
1168 }
1169 
1170 INITIALIZE_PASS(ASanGlobalsMetadataWrapperPass, "asan-globals-md",
1171  "Read metadata to mark which globals should be instrumented "
1172  "when running ASan.",
1173  false, true)
1174 
1176 
1178  AddressSanitizerLegacyPass, "asan",
1179  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,
1180  false)
1181 INITIALIZE_PASS_DEPENDENCY(ASanGlobalsMetadataWrapperPass)
1184  AddressSanitizerLegacyPass, "asan",
1185  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,
1186  false)
1187 
1189  bool Recover,
1190  bool UseAfterScope) {
1191  assert(!CompileKernel || Recover);
1192  return new AddressSanitizerLegacyPass(CompileKernel, Recover, UseAfterScope);
1193 }
1194 
1196 
1198  ModuleAddressSanitizerLegacyPass, "asan-module",
1199  "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
1200  "ModulePass",
1201  false, false)
1202 
1204  bool CompileKernel, bool Recover, bool UseGlobalsGC, bool UseOdrIndicator) {
1205  assert(!CompileKernel || Recover);
1206  return new ModuleAddressSanitizerLegacyPass(CompileKernel, Recover,
1207  UseGlobalsGC, UseOdrIndicator);
1208 }
1209 
1210 static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
1211  size_t Res = countTrailingZeros(TypeSize / 8);
1213  return Res;
1214 }
1215 
1216 /// Create a global describing a source location.
1218  LocationMetadata MD) {
1219  Constant *LocData[] = {
1220  createPrivateGlobalForString(M, MD.Filename, true, kAsanGenPrefix),
1223  };
1224  auto LocStruct = ConstantStruct::getAnon(LocData);
1225  auto GV = new GlobalVariable(M, LocStruct->getType(), true,
1226  GlobalValue::PrivateLinkage, LocStruct,
1227  kAsanGenPrefix);
1229  return GV;
1230 }
1231 
1232 /// Check if \p G has been created by a trusted compiler pass.
1234  // Do not instrument @llvm.global_ctors, @llvm.used, etc.
1235  if (G->getName().startswith("llvm."))
1236  return true;
1237 
1238  // Do not instrument asan globals.
1239  if (G->getName().startswith(kAsanGenPrefix) ||
1240  G->getName().startswith(kSanCovGenPrefix) ||
1241  G->getName().startswith(kODRGenPrefix))
1242  return true;
1243 
1244  // Do not instrument gcov counter arrays.
1245  if (G->getName() == "__llvm_gcov_ctr")
1246  return true;
1247 
1248  return false;
1249 }
1250 
1251 Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
1252  // Shadow >> scale
1253  Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
1254  if (Mapping.Offset == 0) return Shadow;
1255  // (Shadow >> scale) | offset
1256  Value *ShadowBase;
1257  if (LocalDynamicShadow)
1258  ShadowBase = LocalDynamicShadow;
1259  else
1260  ShadowBase = ConstantInt::get(IntptrTy, Mapping.Offset);
1261  if (Mapping.OrShadowOffset)
1262  return IRB.CreateOr(Shadow, ShadowBase);
1263  else
1264  return IRB.CreateAdd(Shadow, ShadowBase);
1265 }
1266 
1267 // Instrument memset/memmove/memcpy
1268 void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
1269  IRBuilder<> IRB(MI);
1270  if (isa<MemTransferInst>(MI)) {
1271  IRB.CreateCall(
1272  isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
1273  {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1274  IRB.CreatePointerCast(MI->getOperand(1), IRB.getInt8PtrTy()),
1275  IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1276  } else if (isa<MemSetInst>(MI)) {
1277  IRB.CreateCall(
1278  AsanMemset,
1279  {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1280  IRB.CreateIntCast(MI->getOperand(1), IRB.getInt32Ty(), false),
1281  IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1282  }
1283  MI->eraseFromParent();
1284 }
1285 
1286 /// Check if we want (and can) handle this alloca.
1287 bool AddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
1288  auto PreviouslySeenAllocaInfo = ProcessedAllocas.find(&AI);
1289 
1290  if (PreviouslySeenAllocaInfo != ProcessedAllocas.end())
1291  return PreviouslySeenAllocaInfo->getSecond();
1292 
1293  bool IsInteresting =
1294  (AI.getAllocatedType()->isSized() &&
1295  // alloca() may be called with 0 size, ignore it.
1296  ((!AI.isStaticAlloca()) || getAllocaSizeInBytes(AI) > 0) &&
1297  // We are only interested in allocas not promotable to registers.
1298  // Promotable allocas are common under -O0.
1300  // inalloca allocas are not treated as static, and we don't want
1301  // dynamic alloca instrumentation for them as well.
1302  !AI.isUsedWithInAlloca() &&
1303  // swifterror allocas are register promoted by ISel
1304  !AI.isSwiftError());
1305 
1306  ProcessedAllocas[&AI] = IsInteresting;
1307  return IsInteresting;
1308 }
1309 
1310 Value *AddressSanitizer::isInterestingMemoryAccess(Instruction *I,
1311  bool *IsWrite,
1312  uint64_t *TypeSize,
1313  unsigned *Alignment,
1314  Value **MaybeMask) {
1315  // Skip memory accesses inserted by another instrumentation.
1316  if (I->getMetadata("nosanitize")) return nullptr;
1317 
1318  // Do not instrument the load fetching the dynamic shadow address.
1319  if (LocalDynamicShadow == I)
1320  return nullptr;
1321 
1322  Value *PtrOperand = nullptr;
1323  const DataLayout &DL = I->getModule()->getDataLayout();
1324  if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
1325  if (!ClInstrumentReads) return nullptr;
1326  *IsWrite = false;
1327  *TypeSize = DL.getTypeStoreSizeInBits(LI->getType());
1328  *Alignment = LI->getAlignment();
1329  PtrOperand = LI->getPointerOperand();
1330  } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
1331  if (!ClInstrumentWrites) return nullptr;
1332  *IsWrite = true;
1333  *TypeSize = DL.getTypeStoreSizeInBits(SI->getValueOperand()->getType());
1334  *Alignment = SI->getAlignment();
1335  PtrOperand = SI->getPointerOperand();
1336  } else if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
1337  if (!ClInstrumentAtomics) return nullptr;
1338  *IsWrite = true;
1339  *TypeSize = DL.getTypeStoreSizeInBits(RMW->getValOperand()->getType());
1340  *Alignment = 0;
1341  PtrOperand = RMW->getPointerOperand();
1342  } else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
1343  if (!ClInstrumentAtomics) return nullptr;
1344  *IsWrite = true;
1345  *TypeSize = DL.getTypeStoreSizeInBits(XCHG->getCompareOperand()->getType());
1346  *Alignment = 0;
1347  PtrOperand = XCHG->getPointerOperand();
1348  } else if (auto CI = dyn_cast<CallInst>(I)) {
1349  auto *F = dyn_cast<Function>(CI->getCalledValue());
1350  if (F && (F->getName().startswith("llvm.masked.load.") ||
1351  F->getName().startswith("llvm.masked.store."))) {
1352  unsigned OpOffset = 0;
1353  if (F->getName().startswith("llvm.masked.store.")) {
1354  if (!ClInstrumentWrites)
1355  return nullptr;
1356  // Masked store has an initial operand for the value.
1357  OpOffset = 1;
1358  *IsWrite = true;
1359  } else {
1360  if (!ClInstrumentReads)
1361  return nullptr;
1362  *IsWrite = false;
1363  }
1364 
1365  auto BasePtr = CI->getOperand(0 + OpOffset);
1366  auto Ty = cast<PointerType>(BasePtr->getType())->getElementType();
1367  *TypeSize = DL.getTypeStoreSizeInBits(Ty);
1368  if (auto AlignmentConstant =
1369  dyn_cast<ConstantInt>(CI->getOperand(1 + OpOffset)))
1370  *Alignment = (unsigned)AlignmentConstant->getZExtValue();
1371  else
1372  *Alignment = 1; // No alignment guarantees. We probably got Undef
1373  if (MaybeMask)
1374  *MaybeMask = CI->getOperand(2 + OpOffset);
1375  PtrOperand = BasePtr;
1376  }
1377  }
1378 
1379  if (PtrOperand) {
1380  // Do not instrument acesses from different address spaces; we cannot deal
1381  // with them.
1382  Type *PtrTy = cast<PointerType>(PtrOperand->getType()->getScalarType());
1383  if (PtrTy->getPointerAddressSpace() != 0)
1384  return nullptr;
1385 
1386  // Ignore swifterror addresses.
1387  // swifterror memory addresses are mem2reg promoted by instruction
1388  // selection. As such they cannot have regular uses like an instrumentation
1389  // function and it makes no sense to track them as memory.
1390  if (PtrOperand->isSwiftError())
1391  return nullptr;
1392  }
1393 
1394  // Treat memory accesses to promotable allocas as non-interesting since they
1395  // will not cause memory violations. This greatly speeds up the instrumented
1396  // executable at -O0.
1398  if (auto AI = dyn_cast_or_null<AllocaInst>(PtrOperand))
1399  return isInterestingAlloca(*AI) ? AI : nullptr;
1400 
1401  return PtrOperand;
1402 }
1403 
1404 static bool isPointerOperand(Value *V) {
1405  return V->getType()->isPointerTy() || isa<PtrToIntInst>(V);
1406 }
1407 
1408 // This is a rough heuristic; it may cause both false positives and
1409 // false negatives. The proper implementation requires cooperation with
1410 // the frontend.
1412  if (ICmpInst *Cmp = dyn_cast<ICmpInst>(I)) {
1413  if (!Cmp->isRelational()) return false;
1414  } else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) {
1415  if (BO->getOpcode() != Instruction::Sub) return false;
1416  } else {
1417  return false;
1418  }
1419  return isPointerOperand(I->getOperand(0)) &&
1421 }
1422 
1423 bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
1424  // If a global variable does not have dynamic initialization we don't
1425  // have to instrument it. However, if a global does not have initializer
1426  // at all, we assume it has dynamic initializer (in other TU).
1427  //
1428  // FIXME: Metadata should be attched directly to the global directly instead
1429  // of being added to llvm.asan.globals.
1430  return G->hasInitializer() && !GlobalsMD.get(G).IsDynInit;
1431 }
1432 
1433 void AddressSanitizer::instrumentPointerComparisonOrSubtraction(
1434  Instruction *I) {
1435  IRBuilder<> IRB(I);
1436  FunctionCallee F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
1437  Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
1438  for (Value *&i : Param) {
1439  if (i->getType()->isPointerTy())
1440  i = IRB.CreatePointerCast(i, IntptrTy);
1441  }
1442  IRB.CreateCall(F, Param);
1443 }
1444 
1446  Instruction *InsertBefore, Value *Addr,
1447  unsigned Alignment, unsigned Granularity,
1448  uint32_t TypeSize, bool IsWrite,
1449  Value *SizeArgument, bool UseCalls,
1450  uint32_t Exp) {
1451  // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check
1452  // if the data is properly aligned.
1453  if ((TypeSize == 8 || TypeSize == 16 || TypeSize == 32 || TypeSize == 64 ||
1454  TypeSize == 128) &&
1455  (Alignment >= Granularity || Alignment == 0 || Alignment >= TypeSize / 8))
1456  return Pass->instrumentAddress(I, InsertBefore, Addr, TypeSize, IsWrite,
1457  nullptr, UseCalls, Exp);
1458  Pass->instrumentUnusualSizeOrAlignment(I, InsertBefore, Addr, TypeSize,
1459  IsWrite, nullptr, UseCalls, Exp);
1460 }
1461 
1463  const DataLayout &DL, Type *IntptrTy,
1464  Value *Mask, Instruction *I,
1465  Value *Addr, unsigned Alignment,
1466  unsigned Granularity, uint32_t TypeSize,
1467  bool IsWrite, Value *SizeArgument,
1468  bool UseCalls, uint32_t Exp) {
1469  auto *VTy = cast<PointerType>(Addr->getType())->getElementType();
1470  uint64_t ElemTypeSize = DL.getTypeStoreSizeInBits(VTy->getScalarType());
1471  unsigned Num = VTy->getVectorNumElements();
1472  auto Zero = ConstantInt::get(IntptrTy, 0);
1473  for (unsigned Idx = 0; Idx < Num; ++Idx) {
1474  Value *InstrumentedAddress = nullptr;
1475  Instruction *InsertBefore = I;
1476  if (auto *Vector = dyn_cast<ConstantVector>(Mask)) {
1477  // dyn_cast as we might get UndefValue
1478  if (auto *Masked = dyn_cast<ConstantInt>(Vector->getOperand(Idx))) {
1479  if (Masked->isZero())
1480  // Mask is constant false, so no instrumentation needed.
1481  continue;
1482  // If we have a true or undef value, fall through to doInstrumentAddress
1483  // with InsertBefore == I
1484  }
1485  } else {
1486  IRBuilder<> IRB(I);
1487  Value *MaskElem = IRB.CreateExtractElement(Mask, Idx);
1488  Instruction *ThenTerm = SplitBlockAndInsertIfThen(MaskElem, I, false);
1489  InsertBefore = ThenTerm;
1490  }
1491 
1492  IRBuilder<> IRB(InsertBefore);
1493  InstrumentedAddress =
1494  IRB.CreateGEP(VTy, Addr, {Zero, ConstantInt::get(IntptrTy, Idx)});
1495  doInstrumentAddress(Pass, I, InsertBefore, InstrumentedAddress, Alignment,
1496  Granularity, ElemTypeSize, IsWrite, SizeArgument,
1497  UseCalls, Exp);
1498  }
1499 }
1500 
1501 void AddressSanitizer::instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
1502  Instruction *I, bool UseCalls,
1503  const DataLayout &DL) {
1504  bool IsWrite = false;
1505  unsigned Alignment = 0;
1506  uint64_t TypeSize = 0;
1507  Value *MaybeMask = nullptr;
1508  Value *Addr =
1509  isInterestingMemoryAccess(I, &IsWrite, &TypeSize, &Alignment, &MaybeMask);
1510  assert(Addr);
1511 
1512  // Optimization experiments.
1513  // The experiments can be used to evaluate potential optimizations that remove
1514  // instrumentation (assess false negatives). Instead of completely removing
1515  // some instrumentation, you set Exp to a non-zero value (mask of optimization
1516  // experiments that want to remove instrumentation of this instruction).
1517  // If Exp is non-zero, this pass will emit special calls into runtime
1518  // (e.g. __asan_report_exp_load1 instead of __asan_report_load1). These calls
1519  // make runtime terminate the program in a special way (with a different
1520  // exit status). Then you run the new compiler on a buggy corpus, collect
1521  // the special terminations (ideally, you don't see them at all -- no false
1522  // negatives) and make the decision on the optimization.
1524 
1525  if (ClOpt && ClOptGlobals) {
1526  // If initialization order checking is disabled, a simple access to a
1527  // dynamically initialized global is always valid.
1529  if (G && (!ClInitializers || GlobalIsLinkerInitialized(G)) &&
1530  isSafeAccess(ObjSizeVis, Addr, TypeSize)) {
1531  NumOptimizedAccessesToGlobalVar++;
1532  return;
1533  }
1534  }
1535 
1536  if (ClOpt && ClOptStack) {
1537  // A direct inbounds access to a stack variable is always valid.
1538  if (isa<AllocaInst>(GetUnderlyingObject(Addr, DL)) &&
1539  isSafeAccess(ObjSizeVis, Addr, TypeSize)) {
1540  NumOptimizedAccessesToStackVar++;
1541  return;
1542  }
1543  }
1544 
1545  if (IsWrite)
1546  NumInstrumentedWrites++;
1547  else
1548  NumInstrumentedReads++;
1549 
1550  unsigned Granularity = 1 << Mapping.Scale;
1551  if (MaybeMask) {
1552  instrumentMaskedLoadOrStore(this, DL, IntptrTy, MaybeMask, I, Addr,
1553  Alignment, Granularity, TypeSize, IsWrite,
1554  nullptr, UseCalls, Exp);
1555  } else {
1556  doInstrumentAddress(this, I, I, Addr, Alignment, Granularity, TypeSize,
1557  IsWrite, nullptr, UseCalls, Exp);
1558  }
1559 }
1560 
1561 Instruction *AddressSanitizer::generateCrashCode(Instruction *InsertBefore,
1562  Value *Addr, bool IsWrite,
1563  size_t AccessSizeIndex,
1564  Value *SizeArgument,
1565  uint32_t Exp) {
1566  IRBuilder<> IRB(InsertBefore);
1567  Value *ExpVal = Exp == 0 ? nullptr : ConstantInt::get(IRB.getInt32Ty(), Exp);
1568  CallInst *Call = nullptr;
1569  if (SizeArgument) {
1570  if (Exp == 0)
1571  Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][0],
1572  {Addr, SizeArgument});
1573  else
1574  Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][1],
1575  {Addr, SizeArgument, ExpVal});
1576  } else {
1577  if (Exp == 0)
1578  Call =
1579  IRB.CreateCall(AsanErrorCallback[IsWrite][0][AccessSizeIndex], Addr);
1580  else
1581  Call = IRB.CreateCall(AsanErrorCallback[IsWrite][1][AccessSizeIndex],
1582  {Addr, ExpVal});
1583  }
1584 
1585  // We don't do Call->setDoesNotReturn() because the BB already has
1586  // UnreachableInst at the end.
1587  // This EmptyAsm is required to avoid callback merge.
1588  IRB.CreateCall(EmptyAsm, {});
1589  return Call;
1590 }
1591 
1592 Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
1593  Value *ShadowValue,
1594  uint32_t TypeSize) {
1595  size_t Granularity = static_cast<size_t>(1) << Mapping.Scale;
1596  // Addr & (Granularity - 1)
1597  Value *LastAccessedByte =
1598  IRB.CreateAnd(AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
1599  // (Addr & (Granularity - 1)) + size - 1
1600  if (TypeSize / 8 > 1)
1601  LastAccessedByte = IRB.CreateAdd(
1602  LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1));
1603  // (uint8_t) ((Addr & (Granularity-1)) + size - 1)
1604  LastAccessedByte =
1605  IRB.CreateIntCast(LastAccessedByte, ShadowValue->getType(), false);
1606  // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
1607  return IRB.CreateICmpSGE(LastAccessedByte, ShadowValue);
1608 }
1609 
1610 void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
1611  Instruction *InsertBefore, Value *Addr,
1612  uint32_t TypeSize, bool IsWrite,
1613  Value *SizeArgument, bool UseCalls,
1614  uint32_t Exp) {
1615  bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
1616 
1617  IRBuilder<> IRB(InsertBefore);
1618  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1619  size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
1620 
1621  if (UseCalls) {
1622  if (Exp == 0)
1623  IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][0][AccessSizeIndex],
1624  AddrLong);
1625  else
1626  IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][1][AccessSizeIndex],
1627  {AddrLong, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1628  return;
1629  }
1630 
1631  if (IsMyriad) {
1632  // Strip the cache bit and do range check.
1633  // AddrLong &= ~kMyriadCacheBitMask32
1634  AddrLong = IRB.CreateAnd(AddrLong, ~kMyriadCacheBitMask32);
1635  // Tag = AddrLong >> kMyriadTagShift
1636  Value *Tag = IRB.CreateLShr(AddrLong, kMyriadTagShift);
1637  // Tag == kMyriadDDRTag
1638  Value *TagCheck =
1639  IRB.CreateICmpEQ(Tag, ConstantInt::get(IntptrTy, kMyriadDDRTag));
1640 
1641  Instruction *TagCheckTerm =
1642  SplitBlockAndInsertIfThen(TagCheck, InsertBefore, false,
1643  MDBuilder(*C).createBranchWeights(1, 100000));
1644  assert(cast<BranchInst>(TagCheckTerm)->isUnconditional());
1645  IRB.SetInsertPoint(TagCheckTerm);
1646  InsertBefore = TagCheckTerm;
1647  }
1648 
1649  Type *ShadowTy =
1650  IntegerType::get(*C, std::max(8U, TypeSize >> Mapping.Scale));
1651  Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
1652  Value *ShadowPtr = memToShadow(AddrLong, IRB);
1653  Value *CmpVal = Constant::getNullValue(ShadowTy);
1654  Value *ShadowValue =
1655  IRB.CreateLoad(ShadowTy, IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));
1656 
1657  Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
1658  size_t Granularity = 1ULL << Mapping.Scale;
1659  Instruction *CrashTerm = nullptr;
1660 
1661  if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
1662  // We use branch weights for the slow path check, to indicate that the slow
1663  // path is rarely taken. This seems to be the case for SPEC benchmarks.
1665  Cmp, InsertBefore, false, MDBuilder(*C).createBranchWeights(1, 100000));
1666  assert(cast<BranchInst>(CheckTerm)->isUnconditional());
1667  BasicBlock *NextBB = CheckTerm->getSuccessor(0);
1668  IRB.SetInsertPoint(CheckTerm);
1669  Value *Cmp2 = createSlowPathCmp(IRB, AddrLong, ShadowValue, TypeSize);
1670  if (Recover) {
1671  CrashTerm = SplitBlockAndInsertIfThen(Cmp2, CheckTerm, false);
1672  } else {
1673  BasicBlock *CrashBlock =
1674  BasicBlock::Create(*C, "", NextBB->getParent(), NextBB);
1675  CrashTerm = new UnreachableInst(*C, CrashBlock);
1676  BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
1677  ReplaceInstWithInst(CheckTerm, NewTerm);
1678  }
1679  } else {
1680  CrashTerm = SplitBlockAndInsertIfThen(Cmp, InsertBefore, !Recover);
1681  }
1682 
1683  Instruction *Crash = generateCrashCode(CrashTerm, AddrLong, IsWrite,
1684  AccessSizeIndex, SizeArgument, Exp);
1685  Crash->setDebugLoc(OrigIns->getDebugLoc());
1686 }
1687 
1688 // Instrument unusual size or unusual alignment.
1689 // We can not do it with a single check, so we do 1-byte check for the first
1690 // and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
1691 // to report the actual access size.
1692 void AddressSanitizer::instrumentUnusualSizeOrAlignment(
1693  Instruction *I, Instruction *InsertBefore, Value *Addr, uint32_t TypeSize,
1694  bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp) {
1695  IRBuilder<> IRB(InsertBefore);
1696  Value *Size = ConstantInt::get(IntptrTy, TypeSize / 8);
1697  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1698  if (UseCalls) {
1699  if (Exp == 0)
1700  IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][0],
1701  {AddrLong, Size});
1702  else
1703  IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][1],
1704  {AddrLong, Size, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1705  } else {
1706  Value *LastByte = IRB.CreateIntToPtr(
1707  IRB.CreateAdd(AddrLong, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
1708  Addr->getType());
1709  instrumentAddress(I, InsertBefore, Addr, 8, IsWrite, Size, false, Exp);
1710  instrumentAddress(I, InsertBefore, LastByte, 8, IsWrite, Size, false, Exp);
1711  }
1712 }
1713 
1714 void ModuleAddressSanitizer::poisonOneInitializer(Function &GlobalInit,
1715  GlobalValue *ModuleName) {
1716  // Set up the arguments to our poison/unpoison functions.
1717  IRBuilder<> IRB(&GlobalInit.front(),
1718  GlobalInit.front().getFirstInsertionPt());
1719 
1720  // Add a call to poison all external globals before the given function starts.
1721  Value *ModuleNameAddr = ConstantExpr::getPointerCast(ModuleName, IntptrTy);
1722  IRB.CreateCall(AsanPoisonGlobals, ModuleNameAddr);
1723 
1724  // Add calls to unpoison all globals before each return instruction.
1725  for (auto &BB : GlobalInit.getBasicBlockList())
1726  if (ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator()))
1727  CallInst::Create(AsanUnpoisonGlobals, "", RI);
1728 }
1729 
1730 void ModuleAddressSanitizer::createInitializerPoisonCalls(
1731  Module &M, GlobalValue *ModuleName) {
1732  GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
1733  if (!GV)
1734  return;
1735 
1737  if (!CA)
1738  return;
1739 
1740  for (Use &OP : CA->operands()) {
1741  if (isa<ConstantAggregateZero>(OP)) continue;
1742  ConstantStruct *CS = cast<ConstantStruct>(OP);
1743 
1744  // Must have a function or null ptr.
1745  if (Function *F = dyn_cast<Function>(CS->getOperand(1))) {
1746  if (F->getName() == kAsanModuleCtorName) continue;
1747  ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1748  // Don't instrument CTORs that will run before asan.module_ctor.
1749  if (Priority->getLimitedValue() <= kAsanCtorAndDtorPriority) continue;
1750  poisonOneInitializer(*F, ModuleName);
1751  }
1752  }
1753 }
1754 
1755 bool ModuleAddressSanitizer::ShouldInstrumentGlobal(GlobalVariable *G) {
1756  Type *Ty = G->getValueType();
1757  LLVM_DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
1758 
1759  // FIXME: Metadata should be attched directly to the global directly instead
1760  // of being added to llvm.asan.globals.
1761  if (GlobalsMD.get(G).IsBlacklisted) return false;
1762  if (!Ty->isSized()) return false;
1763  if (!G->hasInitializer()) return false;
1764  if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
1765  // Two problems with thread-locals:
1766  // - The address of the main thread's copy can't be computed at link-time.
1767  // - Need to poison all copies, not just the main thread's one.
1768  if (G->isThreadLocal()) return false;
1769  // For now, just ignore this Global if the alignment is large.
1770  if (G->getAlignment() > MinRedzoneSizeForGlobal()) return false;
1771 
1772  // For non-COFF targets, only instrument globals known to be defined by this
1773  // TU.
1774  // FIXME: We can instrument comdat globals on ELF if we are using the
1775  // GC-friendly metadata scheme.
1776  if (!TargetTriple.isOSBinFormatCOFF()) {
1777  if (!G->hasExactDefinition() || G->hasComdat())
1778  return false;
1779  } else {
1780  // On COFF, don't instrument non-ODR linkages.
1781  if (G->isInterposable())
1782  return false;
1783  }
1784 
1785  // If a comdat is present, it must have a selection kind that implies ODR
1786  // semantics: no duplicates, any, or exact match.
1787  if (Comdat *C = G->getComdat()) {
1788  switch (C->getSelectionKind()) {
1789  case Comdat::Any:
1790  case Comdat::ExactMatch:
1791  case Comdat::NoDuplicates:
1792  break;
1793  case Comdat::Largest:
1794  case Comdat::SameSize:
1795  return false;
1796  }
1797  }
1798 
1799  if (G->hasSection()) {
1800  StringRef Section = G->getSection();
1801 
1802  // Globals from llvm.metadata aren't emitted, do not instrument them.
1803  if (Section == "llvm.metadata") return false;
1804  // Do not instrument globals from special LLVM sections.
1805  if (Section.find("__llvm") != StringRef::npos || Section.find("__LLVM") != StringRef::npos) return false;
1806 
1807  // Do not instrument function pointers to initialization and termination
1808  // routines: dynamic linker will not properly handle redzones.
1809  if (Section.startswith(".preinit_array") ||
1810  Section.startswith(".init_array") ||
1811  Section.startswith(".fini_array")) {
1812  return false;
1813  }
1814 
1815  // On COFF, if the section name contains '$', it is highly likely that the
1816  // user is using section sorting to create an array of globals similar to
1817  // the way initialization callbacks are registered in .init_array and
1818  // .CRT$XCU. The ATL also registers things in .ATL$__[azm]. Adding redzones
1819  // to such globals is counterproductive, because the intent is that they
1820  // will form an array, and out-of-bounds accesses are expected.
1821  // See https://github.com/google/sanitizers/issues/305
1822  // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
1823  if (TargetTriple.isOSBinFormatCOFF() && Section.contains('$')) {
1824  LLVM_DEBUG(dbgs() << "Ignoring global in sorted section (contains '$'): "
1825  << *G << "\n");
1826  return false;
1827  }
1828 
1829  if (TargetTriple.isOSBinFormatMachO()) {
1830  StringRef ParsedSegment, ParsedSection;
1831  unsigned TAA = 0, StubSize = 0;
1832  bool TAAParsed;
1833  std::string ErrorCode = MCSectionMachO::ParseSectionSpecifier(
1834  Section, ParsedSegment, ParsedSection, TAA, TAAParsed, StubSize);
1835  assert(ErrorCode.empty() && "Invalid section specifier.");
1836 
1837  // Ignore the globals from the __OBJC section. The ObjC runtime assumes
1838  // those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
1839  // them.
1840  if (ParsedSegment == "__OBJC" ||
1841  (ParsedSegment == "__DATA" && ParsedSection.startswith("__objc_"))) {
1842  LLVM_DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G << "\n");
1843  return false;
1844  }
1845  // See https://github.com/google/sanitizers/issues/32
1846  // Constant CFString instances are compiled in the following way:
1847  // -- the string buffer is emitted into
1848  // __TEXT,__cstring,cstring_literals
1849  // -- the constant NSConstantString structure referencing that buffer
1850  // is placed into __DATA,__cfstring
1851  // Therefore there's no point in placing redzones into __DATA,__cfstring.
1852  // Moreover, it causes the linker to crash on OS X 10.7
1853  if (ParsedSegment == "__DATA" && ParsedSection == "__cfstring") {
1854  LLVM_DEBUG(dbgs() << "Ignoring CFString: " << *G << "\n");
1855  return false;
1856  }
1857  // The linker merges the contents of cstring_literals and removes the
1858  // trailing zeroes.
1859  if (ParsedSegment == "__TEXT" && (TAA & MachO::S_CSTRING_LITERALS)) {
1860  LLVM_DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n");
1861  return false;
1862  }
1863  }
1864  }
1865 
1866  return true;
1867 }
1868 
1869 // On Mach-O platforms, we emit global metadata in a separate section of the
1870 // binary in order to allow the linker to properly dead strip. This is only
1871 // supported on recent versions of ld64.
1872 bool ModuleAddressSanitizer::ShouldUseMachOGlobalsSection() const {
1873  if (!TargetTriple.isOSBinFormatMachO())
1874  return false;
1875 
1876  if (TargetTriple.isMacOSX() && !TargetTriple.isMacOSXVersionLT(10, 11))
1877  return true;
1878  if (TargetTriple.isiOS() /* or tvOS */ && !TargetTriple.isOSVersionLT(9))
1879  return true;
1880  if (TargetTriple.isWatchOS() && !TargetTriple.isOSVersionLT(2))
1881  return true;
1882 
1883  return false;
1884 }
1885 
1886 StringRef ModuleAddressSanitizer::getGlobalMetadataSection() const {
1887  switch (TargetTriple.getObjectFormat()) {
1888  case Triple::COFF: return ".ASAN$GL";
1889  case Triple::ELF: return "asan_globals";
1890  case Triple::MachO: return "__DATA,__asan_globals,regular";
1891  default: break;
1892  }
1893  llvm_unreachable("unsupported object format");
1894 }
1895 
1896 void ModuleAddressSanitizer::initializeCallbacks(Module &M) {
1897  IRBuilder<> IRB(*C);
1898 
1899  // Declare our poisoning and unpoisoning functions.
1900  AsanPoisonGlobals =
1901  M.getOrInsertFunction(kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy);
1902  AsanUnpoisonGlobals =
1903  M.getOrInsertFunction(kAsanUnpoisonGlobalsName, IRB.getVoidTy());
1904 
1905  // Declare functions that register/unregister globals.
1906  AsanRegisterGlobals = M.getOrInsertFunction(
1907  kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
1908  AsanUnregisterGlobals = M.getOrInsertFunction(
1909  kAsanUnregisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
1910 
1911  // Declare the functions that find globals in a shared object and then invoke
1912  // the (un)register function on them.
1913  AsanRegisterImageGlobals = M.getOrInsertFunction(
1914  kAsanRegisterImageGlobalsName, IRB.getVoidTy(), IntptrTy);
1915  AsanUnregisterImageGlobals = M.getOrInsertFunction(
1916  kAsanUnregisterImageGlobalsName, IRB.getVoidTy(), IntptrTy);
1917 
1918  AsanRegisterElfGlobals =
1919  M.getOrInsertFunction(kAsanRegisterElfGlobalsName, IRB.getVoidTy(),
1920  IntptrTy, IntptrTy, IntptrTy);
1921  AsanUnregisterElfGlobals =
1922  M.getOrInsertFunction(kAsanUnregisterElfGlobalsName, IRB.getVoidTy(),
1923  IntptrTy, IntptrTy, IntptrTy);
1924 }
1925 
1926 // Put the metadata and the instrumented global in the same group. This ensures
1927 // that the metadata is discarded if the instrumented global is discarded.
1928 void ModuleAddressSanitizer::SetComdatForGlobalMetadata(
1929  GlobalVariable *G, GlobalVariable *Metadata, StringRef InternalSuffix) {
1930  Module &M = *G->getParent();
1931  Comdat *C = G->getComdat();
1932  if (!C) {
1933  if (!G->hasName()) {
1934  // If G is unnamed, it must be internal. Give it an artificial name
1935  // so we can put it in a comdat.
1936  assert(G->hasLocalLinkage());
1937  G->setName(Twine(kAsanGenPrefix) + "_anon_global");
1938  }
1939 
1940  if (!InternalSuffix.empty() && G->hasLocalLinkage()) {
1941  std::string Name = G->getName();
1942  Name += InternalSuffix;
1943  C = M.getOrInsertComdat(Name);
1944  } else {
1945  C = M.getOrInsertComdat(G->getName());
1946  }
1947 
1948  // Make this IMAGE_COMDAT_SELECT_NODUPLICATES on COFF. Also upgrade private
1949  // linkage to internal linkage so that a symbol table entry is emitted. This
1950  // is necessary in order to create the comdat group.
1951  if (TargetTriple.isOSBinFormatCOFF()) {
1953  if (G->hasPrivateLinkage())
1955  }
1956  G->setComdat(C);
1957  }
1958 
1959  assert(G->hasComdat());
1960  Metadata->setComdat(G->getComdat());
1961 }
1962 
1963 // Create a separate metadata global and put it in the appropriate ASan
1964 // global registration section.
1966 ModuleAddressSanitizer::CreateMetadataGlobal(Module &M, Constant *Initializer,
1967  StringRef OriginalName) {
1968  auto Linkage = TargetTriple.isOSBinFormatMachO()
1971  GlobalVariable *Metadata = new GlobalVariable(
1972  M, Initializer->getType(), false, Linkage, Initializer,
1973  Twine("__asan_global_") + GlobalValue::dropLLVMManglingEscape(OriginalName));
1974  Metadata->setSection(getGlobalMetadataSection());
1975  return Metadata;
1976 }
1977 
1978 IRBuilder<> ModuleAddressSanitizer::CreateAsanModuleDtor(Module &M) {
1979  AsanDtorFunction =
1981  GlobalValue::InternalLinkage, kAsanModuleDtorName, &M);
1982  BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
1983 
1984  return IRBuilder<>(ReturnInst::Create(*C, AsanDtorBB));
1985 }
1986 
1987 void ModuleAddressSanitizer::InstrumentGlobalsCOFF(
1988  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
1989  ArrayRef<Constant *> MetadataInitializers) {
1990  assert(ExtendedGlobals.size() == MetadataInitializers.size());
1991  auto &DL = M.getDataLayout();
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  // The MSVC linker always inserts padding when linking incrementally. We
2000  // cope with that by aligning each struct to its size, which must be a power
2001  // of two.
2002  unsigned SizeOfGlobalStruct = DL.getTypeAllocSize(Initializer->getType());
2003  assert(isPowerOf2_32(SizeOfGlobalStruct) &&
2004  "global metadata will not be padded appropriately");
2005  Metadata->setAlignment(SizeOfGlobalStruct);
2006 
2007  SetComdatForGlobalMetadata(G, Metadata, "");
2008  }
2009 }
2010 
2011 void ModuleAddressSanitizer::InstrumentGlobalsELF(
2012  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2013  ArrayRef<Constant *> MetadataInitializers,
2014  const std::string &UniqueModuleId) {
2015  assert(ExtendedGlobals.size() == MetadataInitializers.size());
2016 
2017  SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
2018  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2019  GlobalVariable *G = ExtendedGlobals[i];
2020  GlobalVariable *Metadata =
2021  CreateMetadataGlobal(M, MetadataInitializers[i], G->getName());
2023  Metadata->setMetadata(LLVMContext::MD_associated, MD);
2024  MetadataGlobals[i] = Metadata;
2025 
2026  SetComdatForGlobalMetadata(G, Metadata, UniqueModuleId);
2027  }
2028 
2029  // Update llvm.compiler.used, adding the new metadata globals. This is
2030  // needed so that during LTO these variables stay alive.
2031  if (!MetadataGlobals.empty())
2032  appendToCompilerUsed(M, MetadataGlobals);
2033 
2034  // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2035  // to look up the loaded image that contains it. Second, we can store in it
2036  // whether registration has already occurred, to prevent duplicate
2037  // registration.
2038  //
2039  // Common linkage ensures that there is only one global per shared library.
2040  GlobalVariable *RegisteredFlag = new GlobalVariable(
2041  M, IntptrTy, false, GlobalVariable::CommonLinkage,
2042  ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
2044 
2045  // Create start and stop symbols.
2046  GlobalVariable *StartELFMetadata = new GlobalVariable(
2047  M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2048  "__start_" + getGlobalMetadataSection());
2050  GlobalVariable *StopELFMetadata = new GlobalVariable(
2051  M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2052  "__stop_" + getGlobalMetadataSection());
2054 
2055  // Create a call to register the globals with the runtime.
2056  IRB.CreateCall(AsanRegisterElfGlobals,
2057  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2058  IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2059  IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2060 
2061  // We also need to unregister globals at the end, e.g., when a shared library
2062  // gets closed.
2063  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2064  IRB_Dtor.CreateCall(AsanUnregisterElfGlobals,
2065  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2066  IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2067  IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2068 }
2069 
2070 void ModuleAddressSanitizer::InstrumentGlobalsMachO(
2071  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2072  ArrayRef<Constant *> MetadataInitializers) {
2073  assert(ExtendedGlobals.size() == MetadataInitializers.size());
2074 
2075  // On recent Mach-O platforms, use a structure which binds the liveness of
2076  // the global variable to the metadata struct. Keep the list of "Liveness" GV
2077  // created to be added to llvm.compiler.used
2078  StructType *LivenessTy = StructType::get(IntptrTy, IntptrTy);
2079  SmallVector<GlobalValue *, 16> LivenessGlobals(ExtendedGlobals.size());
2080 
2081  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2082  Constant *Initializer = MetadataInitializers[i];
2083  GlobalVariable *G = ExtendedGlobals[i];
2084  GlobalVariable *Metadata =
2085  CreateMetadataGlobal(M, Initializer, G->getName());
2086 
2087  // On recent Mach-O platforms, we emit the global metadata in a way that
2088  // allows the linker to properly strip dead globals.
2089  auto LivenessBinder =
2090  ConstantStruct::get(LivenessTy, Initializer->getAggregateElement(0u),
2091  ConstantExpr::getPointerCast(Metadata, IntptrTy));
2092  GlobalVariable *Liveness = new GlobalVariable(
2093  M, LivenessTy, false, GlobalVariable::InternalLinkage, LivenessBinder,
2094  Twine("__asan_binder_") + G->getName());
2095  Liveness->setSection("__DATA,__asan_liveness,regular,live_support");
2096  LivenessGlobals[i] = Liveness;
2097  }
2098 
2099  // Update llvm.compiler.used, adding the new liveness globals. This is
2100  // needed so that during LTO these variables stay alive. The alternative
2101  // would be to have the linker handling the LTO symbols, but libLTO
2102  // current API does not expose access to the section for each symbol.
2103  if (!LivenessGlobals.empty())
2104  appendToCompilerUsed(M, LivenessGlobals);
2105 
2106  // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2107  // to look up the loaded image that contains it. Second, we can store in it
2108  // whether registration has already occurred, to prevent duplicate
2109  // registration.
2110  //
2111  // common linkage ensures that there is only one global per shared library.
2112  GlobalVariable *RegisteredFlag = new GlobalVariable(
2113  M, IntptrTy, false, GlobalVariable::CommonLinkage,
2114  ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
2116 
2117  IRB.CreateCall(AsanRegisterImageGlobals,
2118  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2119 
2120  // We also need to unregister globals at the end, e.g., when a shared library
2121  // gets closed.
2122  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2123  IRB_Dtor.CreateCall(AsanUnregisterImageGlobals,
2124  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2125 }
2126 
2127 void ModuleAddressSanitizer::InstrumentGlobalsWithMetadataArray(
2128  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2129  ArrayRef<Constant *> MetadataInitializers) {
2130  assert(ExtendedGlobals.size() == MetadataInitializers.size());
2131  unsigned N = ExtendedGlobals.size();
2132  assert(N > 0);
2133 
2134  // On platforms that don't have a custom metadata section, we emit an array
2135  // of global metadata structures.
2136  ArrayType *ArrayOfGlobalStructTy =
2137  ArrayType::get(MetadataInitializers[0]->getType(), N);
2138  auto AllGlobals = new GlobalVariable(
2139  M, ArrayOfGlobalStructTy, false, GlobalVariable::InternalLinkage,
2140  ConstantArray::get(ArrayOfGlobalStructTy, MetadataInitializers), "");
2141  if (Mapping.Scale > 3)
2142  AllGlobals->setAlignment(1ULL << Mapping.Scale);
2143 
2144  IRB.CreateCall(AsanRegisterGlobals,
2145  {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2146  ConstantInt::get(IntptrTy, N)});
2147 
2148  // We also need to unregister globals at the end, e.g., when a shared library
2149  // gets closed.
2150  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2151  IRB_Dtor.CreateCall(AsanUnregisterGlobals,
2152  {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2153  ConstantInt::get(IntptrTy, N)});
2154 }
2155 
2156 // This function replaces all global variables with new variables that have
2157 // trailing redzones. It also creates a function that poisons
2158 // redzones and inserts this function into llvm.global_ctors.
2159 // Sets *CtorComdat to true if the global registration code emitted into the
2160 // asan constructor is comdat-compatible.
2161 bool ModuleAddressSanitizer::InstrumentGlobals(IRBuilder<> &IRB, Module &M,
2162  bool *CtorComdat) {
2163  *CtorComdat = false;
2164 
2165  SmallVector<GlobalVariable *, 16> GlobalsToChange;
2166 
2167  for (auto &G : M.globals()) {
2168  if (ShouldInstrumentGlobal(&G)) GlobalsToChange.push_back(&G);
2169  }
2170 
2171  size_t n = GlobalsToChange.size();
2172  if (n == 0) {
2173  *CtorComdat = true;
2174  return false;
2175  }
2176 
2177  auto &DL = M.getDataLayout();
2178 
2179  // A global is described by a structure
2180  // size_t beg;
2181  // size_t size;
2182  // size_t size_with_redzone;
2183  // const char *name;
2184  // const char *module_name;
2185  // size_t has_dynamic_init;
2186  // void *source_location;
2187  // size_t odr_indicator;
2188  // We initialize an array of such structures and pass it to a run-time call.
2189  StructType *GlobalStructTy =
2190  StructType::get(IntptrTy, IntptrTy, IntptrTy, IntptrTy, IntptrTy,
2191  IntptrTy, IntptrTy, IntptrTy);
2192  SmallVector<GlobalVariable *, 16> NewGlobals(n);
2193  SmallVector<Constant *, 16> Initializers(n);
2194 
2195  bool HasDynamicallyInitializedGlobals = false;
2196 
2197  // We shouldn't merge same module names, as this string serves as unique
2198  // module ID in runtime.
2200  M, M.getModuleIdentifier(), /*AllowMerging*/ false, kAsanGenPrefix);
2201 
2202  for (size_t i = 0; i < n; i++) {
2203  static const uint64_t kMaxGlobalRedzone = 1 << 18;
2204  GlobalVariable *G = GlobalsToChange[i];
2205 
2206  // FIXME: Metadata should be attched directly to the global directly instead
2207  // of being added to llvm.asan.globals.
2208  auto MD = GlobalsMD.get(G);
2209  StringRef NameForGlobal = G->getName();
2210  // Create string holding the global name (use global name from metadata
2211  // if it's available, otherwise just write the name of global variable).
2213  M, MD.Name.empty() ? NameForGlobal : MD.Name,
2214  /*AllowMerging*/ true, kAsanGenPrefix);
2215 
2216  Type *Ty = G->getValueType();
2217  uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
2218  uint64_t MinRZ = MinRedzoneSizeForGlobal();
2219  // MinRZ <= RZ <= kMaxGlobalRedzone
2220  // and trying to make RZ to be ~ 1/4 of SizeInBytes.
2221  uint64_t RZ = std::max(
2222  MinRZ, std::min(kMaxGlobalRedzone, (SizeInBytes / MinRZ / 4) * MinRZ));
2223  uint64_t RightRedzoneSize = RZ;
2224  // Round up to MinRZ
2225  if (SizeInBytes % MinRZ) RightRedzoneSize += MinRZ - (SizeInBytes % MinRZ);
2226  assert(((RightRedzoneSize + SizeInBytes) % MinRZ) == 0);
2227  Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
2228 
2229  StructType *NewTy = StructType::get(Ty, RightRedZoneTy);
2230  Constant *NewInitializer = ConstantStruct::get(
2231  NewTy, G->getInitializer(), Constant::getNullValue(RightRedZoneTy));
2232 
2233  // Create a new global variable with enough space for a redzone.
2234  GlobalValue::LinkageTypes Linkage = G->getLinkage();
2235  if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
2236  Linkage = GlobalValue::InternalLinkage;
2237  GlobalVariable *NewGlobal =
2238  new GlobalVariable(M, NewTy, G->isConstant(), Linkage, NewInitializer,
2239  "", G, G->getThreadLocalMode());
2240  NewGlobal->copyAttributesFrom(G);
2241  NewGlobal->setComdat(G->getComdat());
2242  NewGlobal->setAlignment(MinRZ);
2243  // Don't fold globals with redzones. ODR violation detector and redzone
2244  // poisoning implicitly creates a dependence on the global's address, so it
2245  // is no longer valid for it to be marked unnamed_addr.
2247 
2248  // Move null-terminated C strings to "__asan_cstring" section on Darwin.
2249  if (TargetTriple.isOSBinFormatMachO() && !G->hasSection() &&
2250  G->isConstant()) {
2251  auto Seq = dyn_cast<ConstantDataSequential>(G->getInitializer());
2252  if (Seq && Seq->isCString())
2253  NewGlobal->setSection("__TEXT,__asan_cstring,regular");
2254  }
2255 
2256  // Transfer the debug info. The payload starts at offset zero so we can
2257  // copy the debug info over as is.
2259  G->getDebugInfo(GVs);
2260  for (auto *GV : GVs)
2261  NewGlobal->addDebugInfo(GV);
2262 
2263  Value *Indices2[2];
2264  Indices2[0] = IRB.getInt32(0);
2265  Indices2[1] = IRB.getInt32(0);
2266 
2267  G->replaceAllUsesWith(
2268  ConstantExpr::getGetElementPtr(NewTy, NewGlobal, Indices2, true));
2269  NewGlobal->takeName(G);
2270  G->eraseFromParent();
2271  NewGlobals[i] = NewGlobal;
2272 
2273  Constant *SourceLoc;
2274  if (!MD.SourceLoc.empty()) {
2275  auto SourceLocGlobal = createPrivateGlobalForSourceLoc(M, MD.SourceLoc);
2276  SourceLoc = ConstantExpr::getPointerCast(SourceLocGlobal, IntptrTy);
2277  } else {
2278  SourceLoc = ConstantInt::get(IntptrTy, 0);
2279  }
2280 
2281  Constant *ODRIndicator = ConstantExpr::getNullValue(IRB.getInt8PtrTy());
2282  GlobalValue *InstrumentedGlobal = NewGlobal;
2283 
2284  bool CanUsePrivateAliases =
2285  TargetTriple.isOSBinFormatELF() || TargetTriple.isOSBinFormatMachO() ||
2286  TargetTriple.isOSBinFormatWasm();
2287  if (CanUsePrivateAliases && UsePrivateAlias) {
2288  // Create local alias for NewGlobal to avoid crash on ODR between
2289  // instrumented and non-instrumented libraries.
2290  InstrumentedGlobal =
2292  }
2293 
2294  // ODR should not happen for local linkage.
2295  if (NewGlobal->hasLocalLinkage()) {
2296  ODRIndicator = ConstantExpr::getIntToPtr(ConstantInt::get(IntptrTy, -1),
2297  IRB.getInt8PtrTy());
2298  } else if (UseOdrIndicator) {
2299  // With local aliases, we need to provide another externally visible
2300  // symbol __odr_asan_XXX to detect ODR violation.
2301  auto *ODRIndicatorSym =
2302  new GlobalVariable(M, IRB.getInt8Ty(), false, Linkage,
2304  kODRGenPrefix + NameForGlobal, nullptr,
2305  NewGlobal->getThreadLocalMode());
2306 
2307  // Set meaningful attributes for indicator symbol.
2308  ODRIndicatorSym->setVisibility(NewGlobal->getVisibility());
2309  ODRIndicatorSym->setDLLStorageClass(NewGlobal->getDLLStorageClass());
2310  ODRIndicatorSym->setAlignment(1);
2311  ODRIndicator = ODRIndicatorSym;
2312  }
2313 
2314  Constant *Initializer = ConstantStruct::get(
2315  GlobalStructTy,
2316  ConstantExpr::getPointerCast(InstrumentedGlobal, IntptrTy),
2317  ConstantInt::get(IntptrTy, SizeInBytes),
2318  ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
2319  ConstantExpr::getPointerCast(Name, IntptrTy),
2320  ConstantExpr::getPointerCast(ModuleName, IntptrTy),
2321  ConstantInt::get(IntptrTy, MD.IsDynInit), SourceLoc,
2322  ConstantExpr::getPointerCast(ODRIndicator, IntptrTy));
2323 
2324  if (ClInitializers && MD.IsDynInit) HasDynamicallyInitializedGlobals = true;
2325 
2326  LLVM_DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
2327 
2328  Initializers[i] = Initializer;
2329  }
2330 
2331  // Add instrumented globals to llvm.compiler.used list to avoid LTO from
2332  // ConstantMerge'ing them.
2333  SmallVector<GlobalValue *, 16> GlobalsToAddToUsedList;
2334  for (size_t i = 0; i < n; i++) {
2335  GlobalVariable *G = NewGlobals[i];
2336  if (G->getName().empty()) continue;
2337  GlobalsToAddToUsedList.push_back(G);
2338  }
2339  appendToCompilerUsed(M, ArrayRef<GlobalValue *>(GlobalsToAddToUsedList));
2340 
2341  std::string ELFUniqueModuleId =
2342  (UseGlobalsGC && TargetTriple.isOSBinFormatELF()) ? getUniqueModuleId(&M)
2343  : "";
2344 
2345  if (!ELFUniqueModuleId.empty()) {
2346  InstrumentGlobalsELF(IRB, M, NewGlobals, Initializers, ELFUniqueModuleId);
2347  *CtorComdat = true;
2348  } else if (UseGlobalsGC && TargetTriple.isOSBinFormatCOFF()) {
2349  InstrumentGlobalsCOFF(IRB, M, NewGlobals, Initializers);
2350  } else if (UseGlobalsGC && ShouldUseMachOGlobalsSection()) {
2351  InstrumentGlobalsMachO(IRB, M, NewGlobals, Initializers);
2352  } else {
2353  InstrumentGlobalsWithMetadataArray(IRB, M, NewGlobals, Initializers);
2354  }
2355 
2356  // Create calls for poisoning before initializers run and unpoisoning after.
2357  if (HasDynamicallyInitializedGlobals)
2358  createInitializerPoisonCalls(M, ModuleName);
2359 
2360  LLVM_DEBUG(dbgs() << M);
2361  return true;
2362 }
2363 
2364 int ModuleAddressSanitizer::GetAsanVersion(const Module &M) const {
2365  int LongSize = M.getDataLayout().getPointerSizeInBits();
2366  bool isAndroid = Triple(M.getTargetTriple()).isAndroid();
2367  int Version = 8;
2368  // 32-bit Android is one version ahead because of the switch to dynamic
2369  // shadow.
2370  Version += (LongSize == 32 && isAndroid);
2371  return Version;
2372 }
2373 
2374 bool ModuleAddressSanitizer::instrumentModule(Module &M) {
2375  initializeCallbacks(M);
2376 
2377  if (CompileKernel)
2378  return false;
2379 
2380  // Create a module constructor. A destructor is created lazily because not all
2381  // platforms, and not all modules need it.
2382  std::string VersionCheckName =
2383  kAsanVersionCheckNamePrefix + std::to_string(GetAsanVersion(M));
2384  std::tie(AsanCtorFunction, std::ignore) = createSanitizerCtorAndInitFunctions(
2385  M, kAsanModuleCtorName, kAsanInitName, /*InitArgTypes=*/{},
2386  /*InitArgs=*/{}, VersionCheckName);
2387 
2388  bool CtorComdat = true;
2389  bool Changed = false;
2390  // TODO(glider): temporarily disabled globals instrumentation for KASan.
2391  if (ClGlobals) {
2392  IRBuilder<> IRB(AsanCtorFunction->getEntryBlock().getTerminator());
2393  Changed |= InstrumentGlobals(IRB, M, &CtorComdat);
2394  }
2395 
2396  // Put the constructor and destructor in comdat if both
2397  // (1) global instrumentation is not TU-specific
2398  // (2) target is ELF.
2399  if (UseCtorComdat && TargetTriple.isOSBinFormatELF() && CtorComdat) {
2400  AsanCtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleCtorName));
2401  appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndDtorPriority,
2402  AsanCtorFunction);
2403  if (AsanDtorFunction) {
2404  AsanDtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleDtorName));
2405  appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndDtorPriority,
2406  AsanDtorFunction);
2407  }
2408  } else {
2409  appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndDtorPriority);
2410  if (AsanDtorFunction)
2411  appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndDtorPriority);
2412  }
2413 
2414  return Changed;
2415 }
2416 
2417 void AddressSanitizer::initializeCallbacks(Module &M) {
2418  IRBuilder<> IRB(*C);
2419  // Create __asan_report* callbacks.
2420  // IsWrite, TypeSize and Exp are encoded in the function name.
2421  for (int Exp = 0; Exp < 2; Exp++) {
2422  for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
2423  const std::string TypeStr = AccessIsWrite ? "store" : "load";
2424  const std::string ExpStr = Exp ? "exp_" : "";
2425  const std::string EndingStr = Recover ? "_noabort" : "";
2426 
2427  SmallVector<Type *, 3> Args2 = {IntptrTy, IntptrTy};
2428  SmallVector<Type *, 2> Args1{1, IntptrTy};
2429  if (Exp) {
2430  Type *ExpType = Type::getInt32Ty(*C);
2431  Args2.push_back(ExpType);
2432  Args1.push_back(ExpType);
2433  }
2434  AsanErrorCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
2435  kAsanReportErrorTemplate + ExpStr + TypeStr + "_n" + EndingStr,
2436  FunctionType::get(IRB.getVoidTy(), Args2, false));
2437 
2438  AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
2439  ClMemoryAccessCallbackPrefix + ExpStr + TypeStr + "N" + EndingStr,
2440  FunctionType::get(IRB.getVoidTy(), Args2, false));
2441 
2442  for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
2443  AccessSizeIndex++) {
2444  const std::string Suffix = TypeStr + itostr(1ULL << AccessSizeIndex);
2445  AsanErrorCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2447  kAsanReportErrorTemplate + ExpStr + Suffix + EndingStr,
2448  FunctionType::get(IRB.getVoidTy(), Args1, false));
2449 
2450  AsanMemoryAccessCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2452  ClMemoryAccessCallbackPrefix + ExpStr + Suffix + EndingStr,
2453  FunctionType::get(IRB.getVoidTy(), Args1, false));
2454  }
2455  }
2456  }
2457 
2458  const std::string MemIntrinCallbackPrefix =
2459  CompileKernel ? std::string("") : ClMemoryAccessCallbackPrefix;
2460  AsanMemmove = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memmove",
2461  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2462  IRB.getInt8PtrTy(), IntptrTy);
2463  AsanMemcpy = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memcpy",
2464  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2465  IRB.getInt8PtrTy(), IntptrTy);
2466  AsanMemset = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memset",
2467  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2468  IRB.getInt32Ty(), IntptrTy);
2469 
2470  AsanHandleNoReturnFunc =
2471  M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy());
2472 
2473  AsanPtrCmpFunction =
2474  M.getOrInsertFunction(kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy);
2475  AsanPtrSubFunction =
2476  M.getOrInsertFunction(kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy);
2477  // We insert an empty inline asm after __asan_report* to avoid callback merge.
2478  EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
2479  StringRef(""), StringRef(""),
2480  /*hasSideEffects=*/true);
2481  if (Mapping.InGlobal)
2482  AsanShadowGlobal = M.getOrInsertGlobal("__asan_shadow",
2483  ArrayType::get(IRB.getInt8Ty(), 0));
2484 }
2485 
2486 bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
2487  // For each NSObject descendant having a +load method, this method is invoked
2488  // by the ObjC runtime before any of the static constructors is called.
2489  // Therefore we need to instrument such methods with a call to __asan_init
2490  // at the beginning in order to initialize our runtime before any access to
2491  // the shadow memory.
2492  // We cannot just ignore these methods, because they may call other
2493  // instrumented functions.
2494  if (F.getName().find(" load]") != std::string::npos) {
2495  FunctionCallee AsanInitFunction =
2497  IRBuilder<> IRB(&F.front(), F.front().begin());
2498  IRB.CreateCall(AsanInitFunction, {});
2499  return true;
2500  }
2501  return false;
2502 }
2503 
2504 void AddressSanitizer::maybeInsertDynamicShadowAtFunctionEntry(Function &F) {
2505  // Generate code only when dynamic addressing is needed.
2506  if (Mapping.Offset != kDynamicShadowSentinel)
2507  return;
2508 
2509  IRBuilder<> IRB(&F.front().front());
2510  if (Mapping.InGlobal) {
2512  // An empty inline asm with input reg == output reg.
2513  // An opaque pointer-to-int cast, basically.
2515  FunctionType::get(IntptrTy, {AsanShadowGlobal->getType()}, false),
2516  StringRef(""), StringRef("=r,0"),
2517  /*hasSideEffects=*/false);
2518  LocalDynamicShadow =
2519  IRB.CreateCall(Asm, {AsanShadowGlobal}, ".asan.shadow");
2520  } else {
2521  LocalDynamicShadow =
2522  IRB.CreatePointerCast(AsanShadowGlobal, IntptrTy, ".asan.shadow");
2523  }
2524  } else {
2525  Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
2526  kAsanShadowMemoryDynamicAddress, IntptrTy);
2527  LocalDynamicShadow = IRB.CreateLoad(IntptrTy, GlobalDynamicAddress);
2528  }
2529 }
2530 
2531 void AddressSanitizer::markEscapedLocalAllocas(Function &F) {
2532  // Find the one possible call to llvm.localescape and pre-mark allocas passed
2533  // to it as uninteresting. This assumes we haven't started processing allocas
2534  // yet. This check is done up front because iterating the use list in
2535  // isInterestingAlloca would be algorithmically slower.
2536  assert(ProcessedAllocas.empty() && "must process localescape before allocas");
2537 
2538  // Try to get the declaration of llvm.localescape. If it's not in the module,
2539  // we can exit early.
2540  if (!F.getParent()->getFunction("llvm.localescape")) return;
2541 
2542  // Look for a call to llvm.localescape call in the entry block. It can't be in
2543  // any other block.
2544  for (Instruction &I : F.getEntryBlock()) {
2546  if (II && II->getIntrinsicID() == Intrinsic::localescape) {
2547  // We found a call. Mark all the allocas passed in as uninteresting.
2548  for (Value *Arg : II->arg_operands()) {
2549  AllocaInst *AI = dyn_cast<AllocaInst>(Arg->stripPointerCasts());
2550  assert(AI && AI->isStaticAlloca() &&
2551  "non-static alloca arg to localescape");
2552  ProcessedAllocas[AI] = false;
2553  }
2554  break;
2555  }
2556  }
2557 }
2558 
2559 bool AddressSanitizer::instrumentFunction(Function &F,
2560  const TargetLibraryInfo *TLI) {
2561  if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
2562  if (!ClDebugFunc.empty() && ClDebugFunc == F.getName()) return false;
2563  if (F.getName().startswith("__asan_")) return false;
2564 
2565  bool FunctionModified = false;
2566 
2567  // If needed, insert __asan_init before checking for SanitizeAddress attr.
2568  // This function needs to be called even if the function body is not
2569  // instrumented.
2570  if (maybeInsertAsanInitAtFunctionEntry(F))
2571  FunctionModified = true;
2572 
2573  // Leave if the function doesn't need instrumentation.
2574  if (!F.hasFnAttribute(Attribute::SanitizeAddress)) return FunctionModified;
2575 
2576  LLVM_DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
2577 
2578  initializeCallbacks(*F.getParent());
2579 
2580  FunctionStateRAII CleanupObj(this);
2581 
2582  maybeInsertDynamicShadowAtFunctionEntry(F);
2583 
2584  // We can't instrument allocas used with llvm.localescape. Only static allocas
2585  // can be passed to that intrinsic.
2586  markEscapedLocalAllocas(F);
2587 
2588  // We want to instrument every address only once per basic block (unless there
2589  // are calls between uses).
2590  SmallPtrSet<Value *, 16> TempsToInstrument;
2591  SmallVector<Instruction *, 16> ToInstrument;
2592  SmallVector<Instruction *, 8> NoReturnCalls;
2594  SmallVector<Instruction *, 16> PointerComparisonsOrSubtracts;
2595  int NumAllocas = 0;
2596  bool IsWrite;
2597  unsigned Alignment;
2598  uint64_t TypeSize;
2599 
2600  // Fill the set of memory operations to instrument.
2601  for (auto &BB : F) {
2602  AllBlocks.push_back(&BB);
2603  TempsToInstrument.clear();
2604  int NumInsnsPerBB = 0;
2605  for (auto &Inst : BB) {
2606  if (LooksLikeCodeInBug11395(&Inst)) return false;
2607  Value *MaybeMask = nullptr;
2608  if (Value *Addr = isInterestingMemoryAccess(&Inst, &IsWrite, &TypeSize,
2609  &Alignment, &MaybeMask)) {
2610  if (ClOpt && ClOptSameTemp) {
2611  // If we have a mask, skip instrumentation if we've already
2612  // instrumented the full object. But don't add to TempsToInstrument
2613  // because we might get another load/store with a different mask.
2614  if (MaybeMask) {
2615  if (TempsToInstrument.count(Addr))
2616  continue; // We've seen this (whole) temp in the current BB.
2617  } else {
2618  if (!TempsToInstrument.insert(Addr).second)
2619  continue; // We've seen this temp in the current BB.
2620  }
2621  }
2622  } else if (ClInvalidPointerPairs &&
2624  PointerComparisonsOrSubtracts.push_back(&Inst);
2625  continue;
2626  } else if (isa<MemIntrinsic>(Inst)) {
2627  // ok, take it.
2628  } else {
2629  if (isa<AllocaInst>(Inst)) NumAllocas++;
2630  CallSite CS(&Inst);
2631  if (CS) {
2632  // A call inside BB.
2633  TempsToInstrument.clear();
2634  if (CS.doesNotReturn() && !CS->getMetadata("nosanitize"))
2635  NoReturnCalls.push_back(CS.getInstruction());
2636  }
2637  if (CallInst *CI = dyn_cast<CallInst>(&Inst))
2639  continue;
2640  }
2641  ToInstrument.push_back(&Inst);
2642  NumInsnsPerBB++;
2643  if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB) break;
2644  }
2645  }
2646 
2647  bool UseCalls =
2650  const DataLayout &DL = F.getParent()->getDataLayout();
2651  ObjectSizeOpts ObjSizeOpts;
2652  ObjSizeOpts.RoundToAlign = true;
2653  ObjectSizeOffsetVisitor ObjSizeVis(DL, TLI, F.getContext(), ObjSizeOpts);
2654 
2655  // Instrument.
2656  int NumInstrumented = 0;
2657  for (auto Inst : ToInstrument) {
2658  if (ClDebugMin < 0 || ClDebugMax < 0 ||
2659  (NumInstrumented >= ClDebugMin && NumInstrumented <= ClDebugMax)) {
2660  if (isInterestingMemoryAccess(Inst, &IsWrite, &TypeSize, &Alignment))
2661  instrumentMop(ObjSizeVis, Inst, UseCalls,
2662  F.getParent()->getDataLayout());
2663  else
2664  instrumentMemIntrinsic(cast<MemIntrinsic>(Inst));
2665  }
2666  NumInstrumented++;
2667  }
2668 
2669  FunctionStackPoisoner FSP(F, *this);
2670  bool ChangedStack = FSP.runOnFunction();
2671 
2672  // We must unpoison the stack before NoReturn calls (throw, _exit, etc).
2673  // See e.g. https://github.com/google/sanitizers/issues/37
2674  for (auto CI : NoReturnCalls) {
2675  IRBuilder<> IRB(CI);
2676  IRB.CreateCall(AsanHandleNoReturnFunc, {});
2677  }
2678 
2679  for (auto Inst : PointerComparisonsOrSubtracts) {
2680  instrumentPointerComparisonOrSubtraction(Inst);
2681  NumInstrumented++;
2682  }
2683 
2684  if (NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty())
2685  FunctionModified = true;
2686 
2687  LLVM_DEBUG(dbgs() << "ASAN done instrumenting: " << FunctionModified << " "
2688  << F << "\n");
2689 
2690  return FunctionModified;
2691 }
2692 
2693 // Workaround for bug 11395: we don't want to instrument stack in functions
2694 // with large assembly blobs (32-bit only), otherwise reg alloc may crash.
2695 // FIXME: remove once the bug 11395 is fixed.
2696 bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
2697  if (LongSize != 32) return false;
2698  CallInst *CI = dyn_cast<CallInst>(I);
2699  if (!CI || !CI->isInlineAsm()) return false;
2700  if (CI->getNumArgOperands() <= 5) return false;
2701  // We have inline assembly with quite a few arguments.
2702  return true;
2703 }
2704 
2705 void FunctionStackPoisoner::initializeCallbacks(Module &M) {
2706  IRBuilder<> IRB(*C);
2707  for (int i = 0; i <= kMaxAsanStackMallocSizeClass; i++) {
2708  std::string Suffix = itostr(i);
2709  AsanStackMallocFunc[i] = M.getOrInsertFunction(
2710  kAsanStackMallocNameTemplate + Suffix, IntptrTy, IntptrTy);
2711  AsanStackFreeFunc[i] =
2712  M.getOrInsertFunction(kAsanStackFreeNameTemplate + Suffix,
2713  IRB.getVoidTy(), IntptrTy, IntptrTy);
2714  }
2715  if (ASan.UseAfterScope) {
2716  AsanPoisonStackMemoryFunc = M.getOrInsertFunction(
2717  kAsanPoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2718  AsanUnpoisonStackMemoryFunc = M.getOrInsertFunction(
2719  kAsanUnpoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2720  }
2721 
2722  for (size_t Val : {0x00, 0xf1, 0xf2, 0xf3, 0xf5, 0xf8}) {
2723  std::ostringstream Name;
2724  Name << kAsanSetShadowPrefix;
2725  Name << std::setw(2) << std::setfill('0') << std::hex << Val;
2726  AsanSetShadowFunc[Val] =
2727  M.getOrInsertFunction(Name.str(), IRB.getVoidTy(), IntptrTy, IntptrTy);
2728  }
2729 
2730  AsanAllocaPoisonFunc = M.getOrInsertFunction(
2731  kAsanAllocaPoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
2732  AsanAllocasUnpoisonFunc = M.getOrInsertFunction(
2733  kAsanAllocasUnpoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
2734 }
2735 
2736 void FunctionStackPoisoner::copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
2737  ArrayRef<uint8_t> ShadowBytes,
2738  size_t Begin, size_t End,
2739  IRBuilder<> &IRB,
2740  Value *ShadowBase) {
2741  if (Begin >= End)
2742  return;
2743 
2744  const size_t LargestStoreSizeInBytes =
2745  std::min<size_t>(sizeof(uint64_t), ASan.LongSize / 8);
2746 
2747  const bool IsLittleEndian = F.getParent()->getDataLayout().isLittleEndian();
2748 
2749  // Poison given range in shadow using larges store size with out leading and
2750  // trailing zeros in ShadowMask. Zeros never change, so they need neither
2751  // poisoning nor up-poisoning. Still we don't mind if some of them get into a
2752  // middle of a store.
2753  for (size_t i = Begin; i < End;) {
2754  if (!ShadowMask[i]) {
2755  assert(!ShadowBytes[i]);
2756  ++i;
2757  continue;
2758  }
2759 
2760  size_t StoreSizeInBytes = LargestStoreSizeInBytes;
2761  // Fit store size into the range.
2762  while (StoreSizeInBytes > End - i)
2763  StoreSizeInBytes /= 2;
2764 
2765  // Minimize store size by trimming trailing zeros.
2766  for (size_t j = StoreSizeInBytes - 1; j && !ShadowMask[i + j]; --j) {
2767  while (j <= StoreSizeInBytes / 2)
2768  StoreSizeInBytes /= 2;
2769  }
2770 
2771  uint64_t Val = 0;
2772  for (size_t j = 0; j < StoreSizeInBytes; j++) {
2773  if (IsLittleEndian)
2774  Val |= (uint64_t)ShadowBytes[i + j] << (8 * j);
2775  else
2776  Val = (Val << 8) | ShadowBytes[i + j];
2777  }
2778 
2779  Value *Ptr = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
2780  Value *Poison = IRB.getIntN(StoreSizeInBytes * 8, Val);
2781  IRB.CreateAlignedStore(
2782  Poison, IRB.CreateIntToPtr(Ptr, Poison->getType()->getPointerTo()), 1);
2783 
2784  i += StoreSizeInBytes;
2785  }
2786 }
2787 
2788 void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2789  ArrayRef<uint8_t> ShadowBytes,
2790  IRBuilder<> &IRB, Value *ShadowBase) {
2791  copyToShadow(ShadowMask, ShadowBytes, 0, ShadowMask.size(), IRB, ShadowBase);
2792 }
2793 
2794 void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2795  ArrayRef<uint8_t> ShadowBytes,
2796  size_t Begin, size_t End,
2797  IRBuilder<> &IRB, Value *ShadowBase) {
2798  assert(ShadowMask.size() == ShadowBytes.size());
2799  size_t Done = Begin;
2800  for (size_t i = Begin, j = Begin + 1; i < End; i = j++) {
2801  if (!ShadowMask[i]) {
2802  assert(!ShadowBytes[i]);
2803  continue;
2804  }
2805  uint8_t Val = ShadowBytes[i];
2806  if (!AsanSetShadowFunc[Val])
2807  continue;
2808 
2809  // Skip same values.
2810  for (; j < End && ShadowMask[j] && Val == ShadowBytes[j]; ++j) {
2811  }
2812 
2813  if (j - i >= ClMaxInlinePoisoningSize) {
2814  copyToShadowInline(ShadowMask, ShadowBytes, Done, i, IRB, ShadowBase);
2815  IRB.CreateCall(AsanSetShadowFunc[Val],
2816  {IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i)),
2817  ConstantInt::get(IntptrTy, j - i)});
2818  Done = j;
2819  }
2820  }
2821 
2822  copyToShadowInline(ShadowMask, ShadowBytes, Done, End, IRB, ShadowBase);
2823 }
2824 
2825 // Fake stack allocator (asan_fake_stack.h) has 11 size classes
2826 // for every power of 2 from kMinStackMallocSize to kMaxAsanStackMallocSizeClass
2827 static int StackMallocSizeClass(uint64_t LocalStackSize) {
2828  assert(LocalStackSize <= kMaxStackMallocSize);
2829  uint64_t MaxSize = kMinStackMallocSize;
2830  for (int i = 0;; i++, MaxSize *= 2)
2831  if (LocalStackSize <= MaxSize) return i;
2832  llvm_unreachable("impossible LocalStackSize");
2833 }
2834 
2835 void FunctionStackPoisoner::copyArgsPassedByValToAllocas() {
2836  Instruction *CopyInsertPoint = &F.front().front();
2837  if (CopyInsertPoint == ASan.LocalDynamicShadow) {
2838  // Insert after the dynamic shadow location is determined
2839  CopyInsertPoint = CopyInsertPoint->getNextNode();
2840  assert(CopyInsertPoint);
2841  }
2842  IRBuilder<> IRB(CopyInsertPoint);
2843  const DataLayout &DL = F.getParent()->getDataLayout();
2844  for (Argument &Arg : F.args()) {
2845  if (Arg.hasByValAttr()) {
2846  Type *Ty = Arg.getType()->getPointerElementType();
2847  unsigned Align = Arg.getParamAlignment();
2848  if (Align == 0) Align = DL.getABITypeAlignment(Ty);
2849 
2850  AllocaInst *AI = IRB.CreateAlloca(
2851  Ty, nullptr,
2852  (Arg.hasName() ? Arg.getName() : "Arg" + Twine(Arg.getArgNo())) +
2853  ".byval");
2854  AI->setAlignment(Align);
2855  Arg.replaceAllUsesWith(AI);
2856 
2857  uint64_t AllocSize = DL.getTypeAllocSize(Ty);
2858  IRB.CreateMemCpy(AI, Align, &Arg, Align, AllocSize);
2859  }
2860  }
2861 }
2862 
2863 PHINode *FunctionStackPoisoner::createPHI(IRBuilder<> &IRB, Value *Cond,
2864  Value *ValueIfTrue,
2865  Instruction *ThenTerm,
2866  Value *ValueIfFalse) {
2867  PHINode *PHI = IRB.CreatePHI(IntptrTy, 2);
2868  BasicBlock *CondBlock = cast<Instruction>(Cond)->getParent();
2869  PHI->addIncoming(ValueIfFalse, CondBlock);
2870  BasicBlock *ThenBlock = ThenTerm->getParent();
2871  PHI->addIncoming(ValueIfTrue, ThenBlock);
2872  return PHI;
2873 }
2874 
2875 Value *FunctionStackPoisoner::createAllocaForLayout(
2876  IRBuilder<> &IRB, const ASanStackFrameLayout &L, bool Dynamic) {
2877  AllocaInst *Alloca;
2878  if (Dynamic) {
2879  Alloca = IRB.CreateAlloca(IRB.getInt8Ty(),
2881  "MyAlloca");
2882  } else {
2883  Alloca = IRB.CreateAlloca(ArrayType::get(IRB.getInt8Ty(), L.FrameSize),
2884  nullptr, "MyAlloca");
2885  assert(Alloca->isStaticAlloca());
2886  }
2887  assert((ClRealignStack & (ClRealignStack - 1)) == 0);
2888  size_t FrameAlignment = std::max(L.FrameAlignment, (size_t)ClRealignStack);
2889  Alloca->setAlignment(FrameAlignment);
2890  return IRB.CreatePointerCast(Alloca, IntptrTy);
2891 }
2892 
2893 void FunctionStackPoisoner::createDynamicAllocasInitStorage() {
2894  BasicBlock &FirstBB = *F.begin();
2895  IRBuilder<> IRB(dyn_cast<Instruction>(FirstBB.begin()));
2896  DynamicAllocaLayout = IRB.CreateAlloca(IntptrTy, nullptr);
2897  IRB.CreateStore(Constant::getNullValue(IntptrTy), DynamicAllocaLayout);
2898  DynamicAllocaLayout->setAlignment(32);
2899 }
2900 
2901 void FunctionStackPoisoner::processDynamicAllocas() {
2902  if (!ClInstrumentDynamicAllocas || DynamicAllocaVec.empty()) {
2903  assert(DynamicAllocaPoisonCallVec.empty());
2904  return;
2905  }
2906 
2907  // Insert poison calls for lifetime intrinsics for dynamic allocas.
2908  for (const auto &APC : DynamicAllocaPoisonCallVec) {
2909  assert(APC.InsBefore);
2910  assert(APC.AI);
2911  assert(ASan.isInterestingAlloca(*APC.AI));
2912  assert(!APC.AI->isStaticAlloca());
2913 
2914  IRBuilder<> IRB(APC.InsBefore);
2915  poisonAlloca(APC.AI, APC.Size, IRB, APC.DoPoison);
2916  // Dynamic allocas will be unpoisoned unconditionally below in
2917  // unpoisonDynamicAllocas.
2918  // Flag that we need unpoison static allocas.
2919  }
2920 
2921  // Handle dynamic allocas.
2922  createDynamicAllocasInitStorage();
2923  for (auto &AI : DynamicAllocaVec)
2924  handleDynamicAllocaCall(AI);
2925  unpoisonDynamicAllocas();
2926 }
2927 
2928 void FunctionStackPoisoner::processStaticAllocas() {
2929  if (AllocaVec.empty()) {
2930  assert(StaticAllocaPoisonCallVec.empty());
2931  return;
2932  }
2933 
2934  int StackMallocIdx = -1;
2935  DebugLoc EntryDebugLocation;
2936  if (auto SP = F.getSubprogram())
2937  EntryDebugLocation = DebugLoc::get(SP->getScopeLine(), 0, SP);
2938 
2939  Instruction *InsBefore = AllocaVec[0];
2940  IRBuilder<> IRB(InsBefore);
2941  IRB.SetCurrentDebugLocation(EntryDebugLocation);
2942 
2943  // Make sure non-instrumented allocas stay in the entry block. Otherwise,
2944  // debug info is broken, because only entry-block allocas are treated as
2945  // regular stack slots.
2946  auto InsBeforeB = InsBefore->getParent();
2947  assert(InsBeforeB == &F.getEntryBlock());
2948  for (auto *AI : StaticAllocasToMoveUp)
2949  if (AI->getParent() == InsBeforeB)
2950  AI->moveBefore(InsBefore);
2951 
2952  // If we have a call to llvm.localescape, keep it in the entry block.
2953  if (LocalEscapeCall) LocalEscapeCall->moveBefore(InsBefore);
2954 
2956  SVD.reserve(AllocaVec.size());
2957  for (AllocaInst *AI : AllocaVec) {
2959  ASan.getAllocaSizeInBytes(*AI),
2960  0,
2961  AI->getAlignment(),
2962  AI,
2963  0,
2964  0};
2965  SVD.push_back(D);
2966  }
2967 
2968  // Minimal header size (left redzone) is 4 pointers,
2969  // i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms.
2970  size_t Granularity = 1ULL << Mapping.Scale;
2971  size_t MinHeaderSize = std::max((size_t)ASan.LongSize / 2, Granularity);
2972  const ASanStackFrameLayout &L =
2973  ComputeASanStackFrameLayout(SVD, Granularity, MinHeaderSize);
2974 
2975  // Build AllocaToSVDMap for ASanStackVariableDescription lookup.
2977  for (auto &Desc : SVD)
2978  AllocaToSVDMap[Desc.AI] = &Desc;
2979 
2980  // Update SVD with information from lifetime intrinsics.
2981  for (const auto &APC : StaticAllocaPoisonCallVec) {
2982  assert(APC.InsBefore);
2983  assert(APC.AI);
2984  assert(ASan.isInterestingAlloca(*APC.AI));
2985  assert(APC.AI->isStaticAlloca());
2986 
2987  ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
2988  Desc.LifetimeSize = Desc.Size;
2989  if (const DILocation *FnLoc = EntryDebugLocation.get()) {
2990  if (const DILocation *LifetimeLoc = APC.InsBefore->getDebugLoc().get()) {
2991  if (LifetimeLoc->getFile() == FnLoc->getFile())
2992  if (unsigned Line = LifetimeLoc->getLine())
2993  Desc.Line = std::min(Desc.Line ? Desc.Line : Line, Line);
2994  }
2995  }
2996  }
2997 
2998  auto DescriptionString = ComputeASanStackFrameDescription(SVD);
2999  LLVM_DEBUG(dbgs() << DescriptionString << " --- " << L.FrameSize << "\n");
3000  uint64_t LocalStackSize = L.FrameSize;
3001  bool DoStackMalloc = ClUseAfterReturn && !ASan.CompileKernel &&
3002  LocalStackSize <= kMaxStackMallocSize;
3003  bool DoDynamicAlloca = ClDynamicAllocaStack;
3004  // Don't do dynamic alloca or stack malloc if:
3005  // 1) There is inline asm: too often it makes assumptions on which registers
3006  // are available.
3007  // 2) There is a returns_twice call (typically setjmp), which is
3008  // optimization-hostile, and doesn't play well with introduced indirect
3009  // register-relative calculation of local variable addresses.
3010  DoDynamicAlloca &= !HasNonEmptyInlineAsm && !HasReturnsTwiceCall;
3011  DoStackMalloc &= !HasNonEmptyInlineAsm && !HasReturnsTwiceCall;
3012 
3013  Value *StaticAlloca =
3014  DoDynamicAlloca ? nullptr : createAllocaForLayout(IRB, L, false);
3015 
3016  Value *FakeStack;
3017  Value *LocalStackBase;
3018  Value *LocalStackBaseAlloca;
3019  bool Deref;
3020 
3021  if (DoStackMalloc) {
3022  LocalStackBaseAlloca =
3023  IRB.CreateAlloca(IntptrTy, nullptr, "asan_local_stack_base");
3024  // void *FakeStack = __asan_option_detect_stack_use_after_return
3025  // ? __asan_stack_malloc_N(LocalStackSize)
3026  // : nullptr;
3027  // void *LocalStackBase = (FakeStack) ? FakeStack : alloca(LocalStackSize);
3028  Constant *OptionDetectUseAfterReturn = F.getParent()->getOrInsertGlobal(
3029  kAsanOptionDetectUseAfterReturn, IRB.getInt32Ty());
3030  Value *UseAfterReturnIsEnabled = IRB.CreateICmpNE(
3031  IRB.CreateLoad(IRB.getInt32Ty(), OptionDetectUseAfterReturn),
3033  Instruction *Term =
3034  SplitBlockAndInsertIfThen(UseAfterReturnIsEnabled, InsBefore, false);
3035  IRBuilder<> IRBIf(Term);
3036  IRBIf.SetCurrentDebugLocation(EntryDebugLocation);
3037  StackMallocIdx = StackMallocSizeClass(LocalStackSize);
3038  assert(StackMallocIdx <= kMaxAsanStackMallocSizeClass);
3039  Value *FakeStackValue =
3040  IRBIf.CreateCall(AsanStackMallocFunc[StackMallocIdx],
3041  ConstantInt::get(IntptrTy, LocalStackSize));
3042  IRB.SetInsertPoint(InsBefore);
3043  IRB.SetCurrentDebugLocation(EntryDebugLocation);
3044  FakeStack = createPHI(IRB, UseAfterReturnIsEnabled, FakeStackValue, Term,
3045  ConstantInt::get(IntptrTy, 0));
3046 
3047  Value *NoFakeStack =
3048  IRB.CreateICmpEQ(FakeStack, Constant::getNullValue(IntptrTy));
3049  Term = SplitBlockAndInsertIfThen(NoFakeStack, InsBefore, false);
3050  IRBIf.SetInsertPoint(Term);
3051  IRBIf.SetCurrentDebugLocation(EntryDebugLocation);
3052  Value *AllocaValue =
3053  DoDynamicAlloca ? createAllocaForLayout(IRBIf, L, true) : StaticAlloca;
3054 
3055  IRB.SetInsertPoint(InsBefore);
3056  IRB.SetCurrentDebugLocation(EntryDebugLocation);
3057  LocalStackBase = createPHI(IRB, NoFakeStack, AllocaValue, Term, FakeStack);
3058  IRB.SetCurrentDebugLocation(EntryDebugLocation);
3059  IRB.CreateStore(LocalStackBase, LocalStackBaseAlloca);
3060  Deref = true;
3061  } else {
3062  // void *FakeStack = nullptr;
3063  // void *LocalStackBase = alloca(LocalStackSize);
3064  FakeStack = ConstantInt::get(IntptrTy, 0);
3065  LocalStackBase =
3066  DoDynamicAlloca ? createAllocaForLayout(IRB, L, true) : StaticAlloca;
3067  LocalStackBaseAlloca = LocalStackBase;
3068  Deref = false;
3069  }
3070 
3071  // Replace Alloca instructions with base+offset.
3072  for (const auto &Desc : SVD) {
3073  AllocaInst *AI = Desc.AI;
3074  replaceDbgDeclareForAlloca(AI, LocalStackBaseAlloca, DIB, Deref,
3075  Desc.Offset, DIExpression::NoDeref);
3076  Value *NewAllocaPtr = IRB.CreateIntToPtr(
3077  IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Desc.Offset)),
3078  AI->getType());
3079  AI->replaceAllUsesWith(NewAllocaPtr);
3080  }
3081 
3082  // The left-most redzone has enough space for at least 4 pointers.
3083  // Write the Magic value to redzone[0].
3084  Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
3086  BasePlus0);
3087  // Write the frame description constant to redzone[1].
3088  Value *BasePlus1 = IRB.CreateIntToPtr(
3089  IRB.CreateAdd(LocalStackBase,
3090  ConstantInt::get(IntptrTy, ASan.LongSize / 8)),
3091  IntptrPtrTy);
3092  GlobalVariable *StackDescriptionGlobal =
3093  createPrivateGlobalForString(*F.getParent(), DescriptionString,
3094  /*AllowMerging*/ true, kAsanGenPrefix);
3095  Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal, IntptrTy);
3096  IRB.CreateStore(Description, BasePlus1);
3097  // Write the PC to redzone[2].
3098  Value *BasePlus2 = IRB.CreateIntToPtr(
3099  IRB.CreateAdd(LocalStackBase,
3100  ConstantInt::get(IntptrTy, 2 * ASan.LongSize / 8)),
3101  IntptrPtrTy);
3102  IRB.CreateStore(IRB.CreatePointerCast(&F, IntptrTy), BasePlus2);
3103 
3104  const auto &ShadowAfterScope = GetShadowBytesAfterScope(SVD, L);
3105 
3106  // Poison the stack red zones at the entry.
3107  Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
3108  // As mask we must use most poisoned case: red zones and after scope.
3109  // As bytes we can use either the same or just red zones only.
3110  copyToShadow(ShadowAfterScope, ShadowAfterScope, IRB, ShadowBase);
3111 
3112  if (!StaticAllocaPoisonCallVec.empty()) {
3113  const auto &ShadowInScope = GetShadowBytes(SVD, L);
3114 
3115  // Poison static allocas near lifetime intrinsics.
3116  for (const auto &APC : StaticAllocaPoisonCallVec) {
3117  const ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3118  assert(Desc.Offset % L.Granularity == 0);
3119  size_t Begin = Desc.Offset / L.Granularity;
3120  size_t End = Begin + (APC.Size + L.Granularity - 1) / L.Granularity;
3121 
3122  IRBuilder<> IRB(APC.InsBefore);
3123  copyToShadow(ShadowAfterScope,
3124  APC.DoPoison ? ShadowAfterScope : ShadowInScope, Begin, End,
3125  IRB, ShadowBase);
3126  }
3127  }
3128 
3129  SmallVector<uint8_t, 64> ShadowClean(ShadowAfterScope.size(), 0);
3130  SmallVector<uint8_t, 64> ShadowAfterReturn;
3131 
3132  // (Un)poison the stack before all ret instructions.
3133  for (auto Ret : RetVec) {
3134  IRBuilder<> IRBRet(Ret);
3135  // Mark the current frame as retired.
3137  BasePlus0);
3138  if (DoStackMalloc) {
3139  assert(StackMallocIdx >= 0);
3140  // if FakeStack != 0 // LocalStackBase == FakeStack
3141  // // In use-after-return mode, poison the whole stack frame.
3142  // if StackMallocIdx <= 4
3143  // // For small sizes inline the whole thing:
3144  // memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
3145  // **SavedFlagPtr(FakeStack) = 0
3146  // else
3147  // __asan_stack_free_N(FakeStack, LocalStackSize)
3148  // else
3149  // <This is not a fake stack; unpoison the redzones>
3150  Value *Cmp =
3151  IRBRet.CreateICmpNE(FakeStack, Constant::getNullValue(IntptrTy));
3152  Instruction *ThenTerm, *ElseTerm;
3153  SplitBlockAndInsertIfThenElse(Cmp, Ret, &ThenTerm, &ElseTerm);
3154 
3155  IRBuilder<> IRBPoison(ThenTerm);
3156  if (StackMallocIdx <= 4) {
3157  int ClassSize = kMinStackMallocSize << StackMallocIdx;
3158  ShadowAfterReturn.resize(ClassSize / L.Granularity,
3160  copyToShadow(ShadowAfterReturn, ShadowAfterReturn, IRBPoison,
3161  ShadowBase);
3162  Value *SavedFlagPtrPtr = IRBPoison.CreateAdd(
3163  FakeStack,
3164  ConstantInt::get(IntptrTy, ClassSize - ASan.LongSize / 8));
3165  Value *SavedFlagPtr = IRBPoison.CreateLoad(
3166  IntptrTy, IRBPoison.CreateIntToPtr(SavedFlagPtrPtr, IntptrPtrTy));
3167  IRBPoison.CreateStore(
3168  Constant::getNullValue(IRBPoison.getInt8Ty()),
3169  IRBPoison.CreateIntToPtr(SavedFlagPtr, IRBPoison.getInt8PtrTy()));
3170  } else {
3171  // For larger frames call __asan_stack_free_*.
3172  IRBPoison.CreateCall(
3173  AsanStackFreeFunc[StackMallocIdx],
3174  {FakeStack, ConstantInt::get(IntptrTy, LocalStackSize)});
3175  }
3176 
3177  IRBuilder<> IRBElse(ElseTerm);
3178  copyToShadow(ShadowAfterScope, ShadowClean, IRBElse, ShadowBase);
3179  } else {
3180  copyToShadow(ShadowAfterScope, ShadowClean, IRBRet, ShadowBase);
3181  }
3182  }
3183 
3184  // We are done. Remove the old unused alloca instructions.
3185  for (auto AI : AllocaVec) AI->eraseFromParent();
3186 }
3187 
3188 void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
3189  IRBuilder<> &IRB, bool DoPoison) {
3190  // For now just insert the call to ASan runtime.
3191  Value *AddrArg = IRB.CreatePointerCast(V, IntptrTy);
3192  Value *SizeArg = ConstantInt::get(IntptrTy, Size);
3193  IRB.CreateCall(
3194  DoPoison ? AsanPoisonStackMemoryFunc : AsanUnpoisonStackMemoryFunc,
3195  {AddrArg, SizeArg});
3196 }
3197 
3198 // Handling llvm.lifetime intrinsics for a given %alloca:
3199 // (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
3200 // (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
3201 // invalid accesses) and unpoison it for llvm.lifetime.start (the memory
3202 // could be poisoned by previous llvm.lifetime.end instruction, as the
3203 // variable may go in and out of scope several times, e.g. in loops).
3204 // (3) if we poisoned at least one %alloca in a function,
3205 // unpoison the whole stack frame at function exit.
3206 
3207 AllocaInst *FunctionStackPoisoner::findAllocaForValue(Value *V) {
3208  if (AllocaInst *AI = dyn_cast<AllocaInst>(V))
3209  // We're interested only in allocas we can handle.
3210  return ASan.isInterestingAlloca(*AI) ? AI : nullptr;
3211  // See if we've already calculated (or started to calculate) alloca for a
3212  // given value.
3213  AllocaForValueMapTy::iterator I = AllocaForValue.find(V);
3214  if (I != AllocaForValue.end()) return I->second;
3215  // Store 0 while we're calculating alloca for value V to avoid
3216  // infinite recursion if the value references itself.
3217  AllocaForValue[V] = nullptr;
3218  AllocaInst *Res = nullptr;
3219  if (CastInst *CI = dyn_cast<CastInst>(V))
3220  Res = findAllocaForValue(CI->getOperand(0));
3221  else if (PHINode *PN = dyn_cast<PHINode>(V)) {
3222  for (Value *IncValue : PN->incoming_values()) {
3223  // Allow self-referencing phi-nodes.
3224  if (IncValue == PN) continue;
3225  AllocaInst *IncValueAI = findAllocaForValue(IncValue);
3226  // AI for incoming values should exist and should all be equal.
3227  if (IncValueAI == nullptr || (Res != nullptr && IncValueAI != Res))
3228  return nullptr;
3229  Res = IncValueAI;
3230  }
3231  } else if (GetElementPtrInst *EP = dyn_cast<GetElementPtrInst>(V)) {
3232  Res = findAllocaForValue(EP->getPointerOperand());
3233  } else {
3234  LLVM_DEBUG(dbgs() << "Alloca search canceled on unknown instruction: " << *V
3235  << "\n");
3236  }
3237  if (Res) AllocaForValue[V] = Res;
3238  return Res;
3239 }
3240 
3241 void FunctionStackPoisoner::handleDynamicAllocaCall(AllocaInst *AI) {
3242  IRBuilder<> IRB(AI);
3243 
3244  const unsigned Align = std::max(kAllocaRzSize, AI->getAlignment());
3245  const uint64_t AllocaRedzoneMask = kAllocaRzSize - 1;
3246 
3247  Value *Zero = Constant::getNullValue(IntptrTy);
3248  Value *AllocaRzSize = ConstantInt::get(IntptrTy, kAllocaRzSize);
3249  Value *AllocaRzMask = ConstantInt::get(IntptrTy, AllocaRedzoneMask);
3250 
3251  // Since we need to extend alloca with additional memory to locate
3252  // redzones, and OldSize is number of allocated blocks with
3253  // ElementSize size, get allocated memory size in bytes by
3254  // OldSize * ElementSize.
3255  const unsigned ElementSize =
3257  Value *OldSize =
3258  IRB.CreateMul(IRB.CreateIntCast(AI->getArraySize(), IntptrTy, false),
3259  ConstantInt::get(IntptrTy, ElementSize));
3260 
3261  // PartialSize = OldSize % 32
3262  Value *PartialSize = IRB.CreateAnd(OldSize, AllocaRzMask);
3263 
3264  // Misalign = kAllocaRzSize - PartialSize;
3265  Value *Misalign = IRB.CreateSub(AllocaRzSize, PartialSize);
3266 
3267  // PartialPadding = Misalign != kAllocaRzSize ? Misalign : 0;
3268  Value *Cond = IRB.CreateICmpNE(Misalign, AllocaRzSize);
3269  Value *PartialPadding = IRB.CreateSelect(Cond, Misalign, Zero);
3270 
3271  // AdditionalChunkSize = Align + PartialPadding + kAllocaRzSize
3272  // Align is added to locate left redzone, PartialPadding for possible
3273  // partial redzone and kAllocaRzSize for right redzone respectively.
3274  Value *AdditionalChunkSize = IRB.CreateAdd(
3275  ConstantInt::get(IntptrTy, Align + kAllocaRzSize), PartialPadding);
3276 
3277  Value *NewSize = IRB.CreateAdd(OldSize, AdditionalChunkSize);
3278 
3279  // Insert new alloca with new NewSize and Align params.
3280  AllocaInst *NewAlloca = IRB.CreateAlloca(IRB.getInt8Ty(), NewSize);
3281  NewAlloca->setAlignment(Align);
3282 
3283  // NewAddress = Address + Align
3284  Value *NewAddress = IRB.CreateAdd(IRB.CreatePtrToInt(NewAlloca, IntptrTy),
3285  ConstantInt::get(IntptrTy, Align));
3286 
3287  // Insert __asan_alloca_poison call for new created alloca.
3288  IRB.CreateCall(AsanAllocaPoisonFunc, {NewAddress, OldSize});
3289 
3290  // Store the last alloca's address to DynamicAllocaLayout. We'll need this
3291  // for unpoisoning stuff.
3292  IRB.CreateStore(IRB.CreatePtrToInt(NewAlloca, IntptrTy), DynamicAllocaLayout);
3293 
3294  Value *NewAddressPtr = IRB.CreateIntToPtr(NewAddress, AI->getType());
3295 
3296  // Replace all uses of AddessReturnedByAlloca with NewAddressPtr.
3297  AI->replaceAllUsesWith(NewAddressPtr);
3298 
3299  // We are done. Erase old alloca from parent.
3300  AI->eraseFromParent();
3301 }
3302 
3303 // isSafeAccess returns true if Addr is always inbounds with respect to its
3304 // base object. For example, it is a field access or an array access with
3305 // constant inbounds index.
3306 bool AddressSanitizer::isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis,
3307  Value *Addr, uint64_t TypeSize) const {
3308  SizeOffsetType SizeOffset = ObjSizeVis.compute(Addr);
3309  if (!ObjSizeVis.bothKnown(SizeOffset)) return false;
3310  uint64_t Size = SizeOffset.first.getZExtValue();
3311  int64_t Offset = SizeOffset.second.getSExtValue();
3312  // Three checks are required to ensure safety:
3313  // . Offset >= 0 (since the offset is given from the base ptr)
3314  // . Size >= Offset (unsigned)
3315  // . Size - Offset >= NeededSize (unsigned)
3316  return Offset >= 0 && Size >= uint64_t(Offset) &&
3317  Size - uint64_t(Offset) >= TypeSize / 8;
3318 }
void setVisibility(VisibilityTypes V)
Definition: GlobalValue.h:238
Pass interface - Implemented by all &#39;passes&#39;.
Definition: Pass.h:80
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:1276
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:89
SymbolTableList< Instruction >::iterator eraseFromParent()
This method unlinks &#39;this&#39; from the containing basic block and deletes it.
Definition: Instruction.cpp:67
static const char *const kAsanSetShadowPrefix
unsigned getAlignment() const
Definition: GlobalObject.h:58
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:110
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:452
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:254
void ReplaceInstWithInst(BasicBlock::InstListType &BIL, BasicBlock::iterator &BI, Instruction *I)
Replace the instruction specified by BI with the instruction specified by I.
void appendToGlobalDtors(Module &M, Function *F, int Priority, Constant *Data=nullptr)
Same as appendToGlobalCtors(), but for global dtors.
Definition: ModuleUtils.cpp:87
bool hasLocalLinkage() const
Definition: GlobalValue.h:435
static const uint64_t kFreeBSD_ShadowOffset64
static cl::opt< bool > ClInitializers("asan-initialization-order", cl::desc("Handle C++ initializer order"), cl::Hidden, cl::init(true))
DILocation * get() const
Get the underlying DILocation.
Definition: DebugLoc.cpp:21
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:694
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:29
AllocaInst * CreateAlloca(Type *Ty, unsigned AddrSpace, Value *ArraySize=nullptr, const Twine &Name="")
Definition: IRBuilder.h:1379
Base class for instruction visitors.
Definition: InstVisitor.h:80
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:1552
Value * CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1878
NodeTy * getNextNode()
Get the next node, or nullptr for the list tail.
Definition: ilist_node.h:288
bool hasPrivateLinkage() const
Definition: GlobalValue.h:434
PassT::Result & getResult(IRUnitT &IR, ExtraArgTs... ExtraArgs)
Get the result of an analysis pass for a given IR unit.
Definition: PassManager.h:769
const Constant * getInitializer() const
getInitializer - Return the initializer for this global variable.
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:139
This class represents lattice values for constants.
Definition: AllocatorList.h:23
static size_t RedzoneSizeForScale(int MappingScale)
static ShadowMapping getShadowMapping(Triple &TargetTriple, int LongSize, bool IsKasan)
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:1392
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:1153
bool isSized(SmallPtrSetImpl< Type *> *Visited=nullptr) const
Return true if it makes sense to take the size of this type.
Definition: Type.h:264
BasicBlock * getSuccessor(unsigned Idx) const
Return the specified successor. This instruction must be a terminator.
void setAlignment(unsigned Align)
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
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:528
static CallInst * Create(FunctionType *Ty, Value *F, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
A handy container for a FunctionType+Callee-pointer pair, which can be passed around as a single enti...
Definition: DerivedTypes.h:164
LLVM_NODISCARD bool startswith(StringRef Prefix) const
Check if this string starts with the given Prefix.
Definition: StringRef.h:256
Available for inspection, not emission.
Definition: GlobalValue.h:49
static const char *const kAsanUnregisterElfGlobalsName
Result run(Module &, ModuleAnalysisManager &)
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:629
static bool isInterestingPointerComparisonOrSubtraction(Instruction *I)
static const char *const kODRGenPrefix
static Constant * getIntToPtr(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1769
bool isSwiftError() const
Return true if this alloca is used as a swifterror argument to a call.
Definition: Instructions.h:135
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:56
bool RoundToAlign
Whether to round the result up to the alignment of allocas, byval arguments, and global variables...
PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM)
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:419
bool hasFnAttribute(Attribute::AttrKind Kind) const
Return true if the function has the attribute.
Definition: Function.h:320
The data referenced by the COMDAT must be the same size.
Definition: Comdat.h:38
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:390
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:388
STATISTIC(NumFunctions, "Total number of functions")
SmallString< 64 > ComputeASanStackFrameDescription(const SmallVectorImpl< ASanStackVariableDescription > &Vars)
A debug info location.
Definition: DebugLoc.h:33
Metadata node.
Definition: Metadata.h:863
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:1068
unsigned getPointerAddressSpace() const
Get the address space of this pointer or pointer vector type.
Definition: DerivedTypes.h:534
bool isOSFuchsia() const
Definition: Triple.h:495
An instruction for reading from memory.
Definition: Instructions.h:167
an instruction that atomically reads a memory location, combines it with another value, and then stores the result back.
Definition: Instructions.h:691
This defines the Use class.
void reserve(size_type N)
Definition: SmallVector.h:369
void setAlignment(unsigned Align)
Definition: Globals.cpp:115
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:58
static Constant * get(ArrayType *T, ArrayRef< Constant *> V)
Definition: Constants.cpp:992
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:274
StoreInst * CreateAlignedStore(Value *Val, Value *Ptr, unsigned Align, bool isVolatile=false)
Definition: IRBuilder.h:1465
iterator begin()
Instruction iterator methods.
Definition: BasicBlock.h:268
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:346
Value * getArgOperand(unsigned i) const
Definition: InstrTypes.h:1155
static const uint64_t kDefaultShadowScale
static const char *const kAsanShadowMemoryDynamicAddress
static const int kAsanStackUseAfterReturnMagic
AnalysisUsage & addRequired()
#define INITIALIZE_PASS_DEPENDENCY(depName)
Definition: PassSupport.h:50
A tuple of MDNodes.
Definition: Metadata.h:1325
const DataLayout & getDataLayout() const
Get the data layout for the module&#39;s target platform.
Definition: Module.cpp:369
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:80
unsigned getAlignment() const
Return the alignment of the memory that is being allocated by the instruction.
Definition: Instructions.h:112
IntegerType * getInt64Ty()
Fetch the type representing a 64-bit integer.
Definition: IRBuilder.h:351
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:96
Class to represent struct types.
Definition: DerivedTypes.h:232
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:55
PointerType * getPointerTo(unsigned AddrSpace=0) const
Return a pointer to the current type.
Definition: Type.cpp:651
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:742
This file contains the simple types necessary to represent the attributes associated with functions a...
The linker may choose any COMDAT.
Definition: Comdat.h:34
ModuleAddressSanitizerPass(bool CompileKernel=false, bool Recover=false, bool UseGlobalGC=true, bool UseOdrIndicator=false)
static const char *const kAsanAllocasUnpoison
Value * CreateAdd(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1049
void setName(const Twine &Name)
Change the name of the value.
Definition: Value.cpp:285
static const char *const kAsanModuleCtorName
LLVM_NODISCARD bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:126
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:341
Type * getVoidTy()
Fetch the type representing void.
Definition: IRBuilder.h:379
StoreInst * CreateStore(Value *Val, Value *Ptr, bool isVolatile=false)
Definition: IRBuilder.h:1421
Value * CreateIntToPtr(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1762
InstrTy * getInstruction() const
Definition: CallSite.h:96
bool isOne() const
This is just a convenience method to make client code smaller for a common case.
Definition: Constants.h:200
static const uint64_t kSmallX86_64ShadowOffsetAlignMask
static const char *const kAsanPoisonStackMemoryName
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:244
SmallVector< uint8_t, 64 > GetShadowBytesAfterScope(const SmallVectorImpl< ASanStackVariableDescription > &Vars, const ASanStackFrameLayout &Layout)
std::string itostr(int64_t X)
Definition: StringExtras.h:238
ConstantDataSequential - A vector or array constant whose element type is a simple 1/2/4/8-byte integ...
Definition: Constants.h:573
static const char *const kSanCovGenPrefix
bool empty() const
Definition: Module.h:607
bool isSwiftError() const
Return true if this value is a swifterror value.
Definition: Value.cpp:730
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:400
bool isUsedWithInAlloca() const
Return true if this alloca is used as an inalloca argument to a call.
Definition: Instructions.h:124
static const int kMaxAsanStackMallocSizeClass
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
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:102
NamedMDNode * getNamedMetadata(const Twine &Name) const
Return the first NamedMDNode in the module with the specified name.
Definition: Module.cpp:250
static cl::opt< bool > ClOpt("asan-opt", cl::desc("Optimize instrumentation"), cl::Hidden, cl::init(true))
AddressSanitizerPass(bool CompileKernel=false, bool Recover=false, bool UseAfterScope=false)
MDNode * getMetadata(unsigned KindID) const
Get the metadata of given kind attached to this Instruction.
Definition: Instruction.h:234
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:32
const APInt & getValue() const
Return the constant as an APInt value reference.
Definition: Constants.h:137
bool isLittleEndian() const
Layout endianness...
Definition: DataLayout.h:232
static const uint64_t kWindowsShadowOffset64
iterator_range< User::op_iterator > arg_operands()
Definition: InstrTypes.h:1147
Value * CreateSub(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1066
bool isiOS() const
Is this an iOS triple.
Definition: Triple.h:456
An instruction for storing to memory.
Definition: Instructions.h:320
void SetCurrentDebugLocation(DebugLoc L)
Set location information used by debugging information.
Definition: IRBuilder.h:150
bool isMinusOne() const
This function will return true iff every bit in this constant is set to true.
Definition: Constants.h:208
static const uint64_t kMyriadTagShift
LinkageTypes getLinkage() const
Definition: GlobalValue.h:450
void replaceAllUsesWith(Value *V)
Change all uses of this to point to a new Value.
Definition: Value.cpp: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:655
static cl::opt< bool > ClAlwaysSlowPath("asan-always-slow-path", cl::desc("use instrumentation with slow path for all accesses"), cl::Hidden, cl::init(false))
iterator_range< op_iterator > operands()
Definition: Metadata.h:1417
GlobalsMetadata()=default
Create a default uninitialized GlobalsMetadata instance.
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:1018
void SetInsertPoint(BasicBlock *TheBB)
This specifies that created instructions should be appended to the end of the specified block...
Definition: IRBuilder.h:126
static const uint64_t kDefaultShadowOffset32
Value * getOperand(unsigned i) const
Definition: User.h:169
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:317
static void instrumentMaskedLoadOrStore(AddressSanitizer *Pass, const DataLayout &DL, Type *IntptrTy, Value *Mask, Instruction *I, Value *Addr, unsigned Alignment, unsigned Granularity, uint32_t TypeSize, bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp)
static PreservedAnalyses none()
Convenience factory function for the empty preserved set.
Definition: PassManager.h:156
Value * CreateOr(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1217
Constant * getAggregateElement(unsigned Elt) const
For aggregates (struct/array/vector) return the constant that corresponds to the specified element if...
Definition: Constants.cpp:344
Type * getScalarType() const
If this is a vector type, return the element type, otherwise return &#39;this&#39;.
Definition: Type.h:303
StringRef getString() const
Definition: Metadata.cpp:463
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:528
ExternalWeak linkage description.
Definition: GlobalValue.h:57
const BasicBlock & getEntryBlock() const
Definition: Function.h:639
an instruction for type-safe pointer arithmetic to access elements of arrays and structs ...
Definition: Instructions.h:873
static const size_t kNumberOfAccessSizes
static MDTuple * get(LLVMContext &Context, ArrayRef< Metadata *> MDs)
Definition: Metadata.h:1165
static bool runOnFunction(Function &F, bool PostInlining)
void initializeModuleAddressSanitizerLegacyPassPass(PassRegistry &)
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:37
The ASanGlobalsMetadataAnalysis initializes and returns a GlobalsMetadata object. ...
static Function * Create(FunctionType *Ty, LinkageTypes Linkage, unsigned AddrSpace, const Twine &N="", Module *M=nullptr)
Definition: Function.h:135
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:148
static std::string ParseSectionSpecifier(StringRef Spec, StringRef &Segment, StringRef &Section, unsigned &TAA, bool &TAAParsed, unsigned &StubSize)
Parse the section specifier indicated by "Spec".
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:153
* 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:216
void setDebugLoc(DebugLoc Loc)
Set the debug location information for this instruction.
Definition: Instruction.h:321
DLLStorageClassTypes getDLLStorageClass() const
Definition: GlobalValue.h:258
std::size_t countTrailingZeros(T Val, ZeroBehavior ZB=ZB_Width)
Count number of 0&#39;s from the least significant bit to the most stopping at the first 1...
Definition: MathExtras.h:119
VisibilityTypes getVisibility() const
Definition: GlobalValue.h:232
constexpr bool isPowerOf2_32(uint32_t Value)
Return true if the argument is a power of two > 0.
Definition: MathExtras.h:428
bool hasName() const
Definition: Value.h:250
LLVM Basic Block Representation.
Definition: BasicBlock.h:57
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
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:64
DISubprogram * getSubprogram() const
Get the attached subprogram.
Definition: Metadata.cpp:1507
Conditional or Unconditional Branch instruction.
static const size_t kMinStackMallocSize
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:148
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:41
bool isInlineAsm() const
Check if this call is an inline asm statement.
Definition: InstrTypes.h:1270
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:2057
bool isPointerTy() const
True if this is an instance of PointerType.
Definition: Type.h:223
static const uint64_t kMIPS32_ShadowOffset32
const Instruction & front() const
Definition: BasicBlock.h:280
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:370
static const uint64_t kFreeBSD_ShadowOffset32
static const uint64_t kAArch64_ShadowOffset64
LLVM_NODISCARD size_t find(char C, size_t From=0) const
Search for the first character C in the string.
Definition: StringRef.h:285
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:160
bool isAndroidVersionLT(unsigned Major) const
Definition: Triple.h:648
Frontend-provided metadata for global variables.
bool isPS4CPU() const
Tests whether the target is the PS4 CPU.
Definition: Triple.h:633
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:1902
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:284
amdgpu Simplify well known AMD library false FunctionCallee Value * Arg
static FunctionType * get(Type *Result, ArrayRef< Type *> Params, bool isVarArg)
This static method is the primary way of constructing a FunctionType.
Definition: Type.cpp:296
static Constant * get(StructType *T, ArrayRef< Constant *> V)
Definition: Constants.cpp:1053
op_range operands()
Definition: User.h:237
static BasicBlock * Create(LLVMContext &Context, const Twine &Name="", Function *Parent=nullptr, BasicBlock *InsertBefore=nullptr)
Creates a new BasicBlock.
Definition: BasicBlock.h:99
Value * CreateICmpEQ(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1874
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:381
static cl::opt< bool > ClOptGlobals("asan-opt-globals", cl::desc("Don't instrument scalar globals"), cl::Hidden, cl::init(true))
LLVM_NODISCARD bool contains(StringRef Other) const
Return true if the given string is a substring of *this, and false otherwise.
Definition: StringRef.h:432
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:35
Value * CreateExtractElement(Value *Vec, Value *Idx, const Twine &Name="")
Definition: IRBuilder.h:2077
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:123
Comdat * getOrInsertComdat(StringRef Name)
Return the Comdat in the module with the specified name.
Definition: Module.cpp:482
static PreservedAnalyses all()
Construct a special preserved set that preserves all passes.
Definition: PassManager.h:159
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:92
std::pair< APInt, APInt > SizeOffsetType
size_t size() const
Definition: SmallVector.h:52
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:384
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:37
static const uint64_t kWindowsShadowOffset32
Value * GetUnderlyingObject(Value *V, const DataLayout &DL, unsigned MaxLookup=6)
This method strips off any GEP address adjustments and pointer casts from the specified value...
INITIALIZE_PASS_END(RegBankSelect, DEBUG_TYPE, "Assign register bank of generic virtual registers", false, false) RegBankSelect
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Value * CreateMul(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1083
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:105
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:43
static const char *const kAsanRegisterGlobalsName
Intrinsic::ID getIntrinsicID() const
Return the intrinsic ID of this intrinsic.
Definition: IntrinsicInst.h:50
PHINode * CreatePHI(Type *Ty, unsigned NumReservedValues, const Twine &Name="")
Definition: IRBuilder.h:2004
Value * CreateGEP(Value *Ptr, ArrayRef< Value *> IdxList, const Twine &Name="")
Definition: IRBuilder.h:1493
static Constant * getPointerCast(Constant *C, Type *Ty)
Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant expression.
Definition: Constants.cpp:1596
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:239
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.
Frontend-provided metadata for source location.
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:250
This is the shared class of boolean and integer constants.
Definition: Constants.h:83
void setSelectionKind(SelectionKind Val)
Definition: Comdat.h:45
static const char *const kAsanStackMallocNameTemplate
static const char *const kAsanUnpoisonStackMemoryName
Evaluate the size and offset of an object pointed to by a Value* statically.
An analysis over an "inner" IR unit that provides access to an analysis manager over a "outer" IR uni...
Definition: PassManager.h:1153
Value * CreateIntCast(Value *V, Type *DestTy, bool isSigned, const Twine &Name="")
Definition: IRBuilder.h:1836
static ValueAsMetadata * get(Value *V)
Definition: Metadata.cpp:348
bool hasSection() const
Check if this global has a custom object file section.
Definition: GlobalObject.h:81
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:841
INITIALIZE_PASS(ASanGlobalsMetadataWrapperPass, "asan-globals-md", "Read metadata to mark which globals should be instrumented " "when running ASan.", false, true) char AddressSanitizerLegacyPass INITIALIZE_PASS_BEGIN(AddressSanitizerLegacyPass, "asan", "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false, false) INITIALIZE_PASS_END(AddressSanitizerLegacyPass
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:749
const DataFlowGraph & G
Definition: RDFGraph.cpp:202
bool isOSLinux() const
Tests whether the OS is Linux.
Definition: Triple.h:576
static const uint64_t kDefaultShadowOffset64
ConstantInt * getInt32(uint32_t C)
Get a constant 32-bit value.
Definition: IRBuilder.h:306
static IntegerType * getIntNTy(LLVMContext &C, unsigned N)
Definition: Type.cpp:179
FunctionPass * createAddressSanitizerFunctionPass(bool CompileKernel=false, bool Recover=false, bool UseAfterScope=false)
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:445
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:631
static BranchInst * Create(BasicBlock *IfTrue, Instruction *InsertBefore=nullptr)
The linker will choose the largest COMDAT.
Definition: Comdat.h:36
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:83
FunctionCallee getOrInsertFunction(StringRef Name, FunctionType *T, AttributeList AttributeList)
Look up the specified function in the module symbol table.
Definition: Module.cpp:143
static cl::opt< bool > ClInvalidPointerPairs("asan-detect-invalid-pointer-pair", cl::desc("Instrument <, <=, >, >=, - with pointer operands"), cl::Hidden, cl::init(false))
static bool isPointerOperand(Value *V)
static cl::opt< int > ClInstrumentationWithCallsThreshold("asan-instrumentation-with-call-threshold", cl::desc("If the function being instrumented contains more than " "this number of memory accesses, use callbacks instead of " "inline checks (-1 means never use callbacks)."), cl::Hidden, cl::init(7000))
void setLinkage(LinkageTypes LT)
Definition: GlobalValue.h:444
bool isOSFreeBSD() const
Definition: Triple.h:491
INITIALIZE_PASS(ASanGlobalsMetadataWrapperPass, "asan-globals-md", "Read metadata to mark which globals should be instrumented " "when running ASan.", false, true) char AddressSanitizerLegacyPass AddressSanitizer
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
Function * getFunction(StringRef Name) const
Look up the specified function in the module symbol table.
Definition: Module.cpp:174
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:55
ConstantArray - Constant Array Declarations.
Definition: Constants.h:413
static StringRef dropLLVMManglingEscape(StringRef Name)
If the given string begins with the GlobalValue name mangling escape character &#39;\1&#39;, drop it.
Definition: GlobalValue.h:471
static const uint64_t kSystemZ_ShadowOffset64
static GlobalVariable * createPrivateGlobalForSourceLoc(Module &M, LocationMetadata MD)
Create a global describing a source location.
LinkageTypes
An enumeration for the kinds of linkage for global values.
Definition: GlobalValue.h:47
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))
void setPreservesAll()
Set by analyses that do not transform their input at all.
IntegerType * getInt8Ty()
Fetch the type representing an 8-bit integer.
Definition: IRBuilder.h:336
Value * CreatePointerCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1813
bool hasComdat() const
Definition: GlobalObject.h:99
void initializeAddressSanitizerLegacyPassPass(PassRegistry &)
void setMetadata(unsigned KindID, MDNode *MD)
Set a particular kind of metadata attachment.
Definition: Metadata.cpp:1433
FunctionCallee declareSanitizerInitFunction(Module &M, StringRef InitName, ArrayRef< Type *> InitArgTypes)
static cl::opt< bool > ClSkipPromotableAllocas("asan-skip-promotable-allocas", cl::desc("Do not instrument promotable allocas"), cl::Hidden, cl::init(true))
const Comdat * getComdat() const
Definition: GlobalObject.h:100
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:461
ModulePass * createModuleAddressSanitizerLegacyPassPass(bool CompileKernel=false, bool Recover=false, bool UseGlobalsGC=true, bool UseOdrIndicator=true)
bool isMIPS32() const
Tests whether the target is MIPS 32-bit (little and big endian).
Definition: Triple.h:689
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:1153
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:324
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:204
void setUnnamedAddr(UnnamedAddr Val)
Definition: GlobalValue.h:215
static const size_t npos
Definition: StringRef.h:50
static IntegerType * getInt32Ty(LLVMContext &C)
Definition: Type.cpp:175
bool isThumb() const
Tests whether the target is Thumb (little and big endian).
Definition: Triple.h:674
INITIALIZE_PASS(ModuleAddressSanitizerLegacyPass, "asan-module", "AddressSanitizer: detects use-after-free and out-of-bounds bugs." "ModulePass", false, false) ModulePass *llvm
static int StackMallocSizeClass(uint64_t LocalStackSize)
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:55
void initializeASanGlobalsMetadataWrapperPassPass(PassRegistry &)
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:481
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:406
void copyAttributesFrom(const GlobalVariable *Src)
copyAttributesFrom - copy all additional attributes (those not needed to create a GlobalVariable) fro...
Definition: Globals.cpp:385
const Function * getParent() const
Return the enclosing method, or null if none.
Definition: BasicBlock.h:106
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:224
static ArrayType * get(Type *ElementType, uint64_t NumElements)
This static method is the primary way to construct an ArrayType.
Definition: Type.cpp:580
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:322
Type * getValueType() const
Definition: GlobalValue.h:275
const BasicBlockListType & getBasicBlockList() const
Get the underlying elements of the Function...
Definition: Function.h:632
static const uint64_t kNetBSD_ShadowOffset64
uint32_t Size
Definition: Profile.cpp:46
static const uint64_t kNetBSDKasan_ShadowOffset64
Rename collisions when linking (static functions).
Definition: GlobalValue.h:55
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:2837
CallInst * CreateCall(FunctionType *FTy, Value *Callee, ArrayRef< Value *> Args=None, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:2009
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:42
static const uint64_t kPS4CPU_ShadowOffset64
static const char *const kAsanModuleDtorName
Value * CreateAnd(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1199
Value * CreatePtrToInt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1757
const std::string to_string(const T &Value)
Definition: ScopedPrinter.h:61
static uint64_t getAllocaSizeInBytes(const AllocaInst &AI)
static const char *const kAsanUnregisterGlobalsName
Analysis pass providing the TargetLibraryInfo.
iterator_range< df_iterator< T > > depth_first(const T &G)
static const char *const kAsanUnpoisonGlobalsName
LLVM_NODISCARD const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:122
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:662
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:565
LLVM Value Representation.
Definition: Value.h:72
void setAlignment(unsigned Align)
static const uint64_t kPPC64_ShadowOffset64
static const unsigned kAllocaRzSize
bool doesNotReturn() const
Determine if the call cannot return.
Definition: CallSite.h:505
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:80
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:86
bool isAndroid() const
Tests whether the target is Android.
Definition: Triple.h:646
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:468
Value * CreateLShr(Value *LHS, Value *RHS, const Twine &Name="", bool isExact=false)
Definition: IRBuilder.h:1159
void addDebugInfo(DIGlobalVariableExpression *GV)
Attach a DIGlobalVariableExpression.
Definition: Metadata.cpp:1520
bool isThreadLocal() const
If the value is "Thread Local", its value isn&#39;t shared by the threads.
Definition: GlobalValue.h:246
static const char *const kAsanAllocaPoison
static const char *const kAsanHandleNoReturnName
iterator_range< global_iterator > globals()
Definition: Module.h:587
IRTranslator LLVM IR MI
static const size_t kMaxStackMallocSize
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
Various options to control the behavior of getObjectSize.
A single uniqued string.
Definition: Metadata.h:603
A container for analyses that lazily runs them and caches their results.
static cl::opt< bool > ClOptStack("asan-opt-stack", cl::desc("Don't instrument scalar stack variables"), cl::Hidden, cl::init(false))
std::pair< Function *, FunctionCallee > 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.
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:1074
#define LLVM_DEBUG(X)
Definition: Debug.h:122
Root of the metadata hierarchy.
Definition: Metadata.h:57
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:904
void setSection(StringRef S)
Change the section for this global.
Definition: Globals.cpp:188
A special type used by analysis passes to provide an address that identifies that particular analysis...
Definition: PassManager.h:70
#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:422
Instruction * SplitBlockAndInsertIfThen(Value *Cond, Instruction *SplitBefore, bool Unreachable, MDNode *BranchWeights=nullptr, DominatorTree *DT=nullptr, LoopInfo *LI=nullptr, BasicBlock *ThenBlock=nullptr)
Split the containing block at the specified instruction - everything before SplitBefore stays in the ...
bool isARM() const
Tests whether the target is ARM (little and big endian).
Definition: Triple.h:679
std::vector< uint32_t > Metadata
PAL metadata represented as a vector.
iterator_range< arg_iterator > args()
Definition: Function.h:688
A wrapper class for inspecting calls to intrinsic functions.
Definition: IntrinsicInst.h:43
const BasicBlock * getParent() const
Definition: Instruction.h:66
an instruction to allocate memory on the stack
Definition: Instructions.h:59
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:344