LLVM  10.0.0svn
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 kSmallX86_64ShadowOffsetBase = 0x7FFFFFFF; // < 2G.
98 static const uint64_t kSmallX86_64ShadowOffsetAlignMask = ~0xFFFULL;
99 static const uint64_t kLinuxKasan_ShadowOffset64 = 0xdffffc0000000000;
100 static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 44;
101 static const uint64_t kSystemZ_ShadowOffset64 = 1ULL << 52;
102 static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa0000;
103 static const uint64_t kMIPS64_ShadowOffset64 = 1ULL << 37;
104 static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 36;
105 static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
106 static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
107 static const uint64_t kNetBSD_ShadowOffset32 = 1ULL << 30;
108 static const uint64_t kNetBSD_ShadowOffset64 = 1ULL << 46;
109 static const uint64_t kNetBSDKasan_ShadowOffset64 = 0xdfff900000000000;
110 static const uint64_t kPS4CPU_ShadowOffset64 = 1ULL << 40;
111 static const uint64_t kWindowsShadowOffset32 = 3ULL << 28;
112 static const uint64_t kEmscriptenShadowOffset = 0;
113 
114 static const uint64_t kMyriadShadowScale = 5;
115 static const uint64_t kMyriadMemoryOffset32 = 0x80000000ULL;
116 static const uint64_t kMyriadMemorySize32 = 0x20000000ULL;
117 static const uint64_t kMyriadTagShift = 29;
118 static const uint64_t kMyriadDDRTag = 4;
119 static const uint64_t kMyriadCacheBitMask32 = 0x40000000ULL;
120 
121 // The shadow memory space is dynamically allocated.
123 
124 static const size_t kMinStackMallocSize = 1 << 6; // 64B
125 static const size_t kMaxStackMallocSize = 1 << 16; // 64K
126 static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
127 static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;
128 
129 static const char *const kAsanModuleCtorName = "asan.module_ctor";
130 static const char *const kAsanModuleDtorName = "asan.module_dtor";
131 static const uint64_t kAsanCtorAndDtorPriority = 1;
132 // On Emscripten, the system needs more than one priorities for constructors.
133 static const uint64_t kAsanEmscriptenCtorAndDtorPriority = 50;
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 
197  "asan-guard-against-version-mismatch",
198  cl::desc("Guard against compiler/runtime version mismatch."),
199  cl::Hidden, cl::init(true));
200 
201 // This flag may need to be replaced with -f[no-]asan-reads.
202 static cl::opt<bool> ClInstrumentReads("asan-instrument-reads",
203  cl::desc("instrument read instructions"),
204  cl::Hidden, cl::init(true));
205 
207  "asan-instrument-writes", cl::desc("instrument write instructions"),
208  cl::Hidden, cl::init(true));
209 
211  "asan-instrument-atomics",
212  cl::desc("instrument atomic instructions (rmw, cmpxchg)"), cl::Hidden,
213  cl::init(true));
214 
216  "asan-always-slow-path",
217  cl::desc("use instrumentation with slow path for all accesses"), cl::Hidden,
218  cl::init(false));
219 
221  "asan-force-dynamic-shadow",
222  cl::desc("Load shadow address into a local variable for each function"),
223  cl::Hidden, cl::init(false));
224 
225 static cl::opt<bool>
226  ClWithIfunc("asan-with-ifunc",
227  cl::desc("Access dynamic shadow through an ifunc global on "
228  "platforms that support this"),
229  cl::Hidden, cl::init(true));
230 
232  "asan-with-ifunc-suppress-remat",
233  cl::desc("Suppress rematerialization of dynamic shadow address by passing "
234  "it through inline asm in prologue."),
235  cl::Hidden, cl::init(true));
236 
237 // This flag limits the number of instructions to be instrumented
238 // in any given BB. Normally, this should be set to unlimited (INT_MAX),
239 // but due to http://llvm.org/bugs/show_bug.cgi?id=12652 we temporary
240 // set it to 10000.
242  "asan-max-ins-per-bb", cl::init(10000),
243  cl::desc("maximal number of instructions to instrument in any given BB"),
244  cl::Hidden);
245 
246 // This flag may need to be replaced with -f[no]asan-stack.
247 static cl::opt<bool> ClStack("asan-stack", cl::desc("Handle stack memory"),
248  cl::Hidden, cl::init(true));
250  "asan-max-inline-poisoning-size",
251  cl::desc(
252  "Inline shadow poisoning for blocks up to the given size in bytes."),
253  cl::Hidden, cl::init(64));
254 
255 static cl::opt<bool> ClUseAfterReturn("asan-use-after-return",
256  cl::desc("Check stack-use-after-return"),
257  cl::Hidden, cl::init(true));
258 
259 static cl::opt<bool> ClRedzoneByvalArgs("asan-redzone-byval-args",
260  cl::desc("Create redzones for byval "
261  "arguments (extra copy "
262  "required)"), cl::Hidden,
263  cl::init(true));
264 
265 static cl::opt<bool> ClUseAfterScope("asan-use-after-scope",
266  cl::desc("Check stack-use-after-scope"),
267  cl::Hidden, cl::init(false));
268 
269 // This flag may need to be replaced with -f[no]asan-globals.
270 static cl::opt<bool> ClGlobals("asan-globals",
271  cl::desc("Handle global objects"), cl::Hidden,
272  cl::init(true));
273 
274 static cl::opt<bool> ClInitializers("asan-initialization-order",
275  cl::desc("Handle C++ initializer order"),
276  cl::Hidden, cl::init(true));
277 
279  "asan-detect-invalid-pointer-pair",
280  cl::desc("Instrument <, <=, >, >=, - with pointer operands"), cl::Hidden,
281  cl::init(false));
282 
284  "asan-detect-invalid-pointer-cmp",
285  cl::desc("Instrument <, <=, >, >= with pointer operands"), cl::Hidden,
286  cl::init(false));
287 
289  "asan-detect-invalid-pointer-sub",
290  cl::desc("Instrument - operations with pointer operands"), cl::Hidden,
291  cl::init(false));
292 
294  "asan-realign-stack",
295  cl::desc("Realign stack to the value of this flag (power of two)"),
296  cl::Hidden, cl::init(32));
297 
299  "asan-instrumentation-with-call-threshold",
300  cl::desc(
301  "If the function being instrumented contains more than "
302  "this number of memory accesses, use callbacks instead of "
303  "inline checks (-1 means never use callbacks)."),
304  cl::Hidden, cl::init(7000));
305 
307  "asan-memory-access-callback-prefix",
308  cl::desc("Prefix for memory access callbacks"), cl::Hidden,
309  cl::init("__asan_"));
310 
311 static cl::opt<bool>
312  ClInstrumentDynamicAllocas("asan-instrument-dynamic-allocas",
313  cl::desc("instrument dynamic allocas"),
314  cl::Hidden, cl::init(true));
315 
317  "asan-skip-promotable-allocas",
318  cl::desc("Do not instrument promotable allocas"), cl::Hidden,
319  cl::init(true));
320 
321 // These flags allow to change the shadow mapping.
322 // The shadow mapping looks like
323 // Shadow = (Mem >> scale) + offset
324 
325 static cl::opt<int> ClMappingScale("asan-mapping-scale",
326  cl::desc("scale of asan shadow mapping"),
327  cl::Hidden, cl::init(0));
328 
329 static cl::opt<uint64_t>
330  ClMappingOffset("asan-mapping-offset",
331  cl::desc("offset of asan shadow mapping [EXPERIMENTAL]"),
332  cl::Hidden, cl::init(0));
333 
334 // Optimization flags. Not user visible, used mostly for testing
335 // and benchmarking the tool.
336 
337 static cl::opt<bool> ClOpt("asan-opt", cl::desc("Optimize instrumentation"),
338  cl::Hidden, cl::init(true));
339 
341  "asan-opt-same-temp", cl::desc("Instrument the same temp just once"),
342  cl::Hidden, cl::init(true));
343 
344 static cl::opt<bool> ClOptGlobals("asan-opt-globals",
345  cl::desc("Don't instrument scalar globals"),
346  cl::Hidden, cl::init(true));
347 
349  "asan-opt-stack", cl::desc("Don't instrument scalar stack variables"),
350  cl::Hidden, cl::init(false));
351 
353  "asan-stack-dynamic-alloca",
354  cl::desc("Use dynamic alloca to represent stack variables"), cl::Hidden,
355  cl::init(true));
356 
358  "asan-force-experiment",
359  cl::desc("Force optimization experiment (for testing)"), cl::Hidden,
360  cl::init(0));
361 
362 static cl::opt<bool>
363  ClUsePrivateAlias("asan-use-private-alias",
364  cl::desc("Use private aliases for global variables"),
365  cl::Hidden, cl::init(false));
366 
367 static cl::opt<bool>
368  ClUseOdrIndicator("asan-use-odr-indicator",
369  cl::desc("Use odr indicators to improve ODR reporting"),
370  cl::Hidden, cl::init(false));
371 
372 static cl::opt<bool>
373  ClUseGlobalsGC("asan-globals-live-support",
374  cl::desc("Use linker features to support dead "
375  "code stripping of globals"),
376  cl::Hidden, cl::init(true));
377 
378 // This is on by default even though there is a bug in gold:
379 // https://sourceware.org/bugzilla/show_bug.cgi?id=19002
380 static cl::opt<bool>
381  ClWithComdat("asan-with-comdat",
382  cl::desc("Place ASan constructors in comdat sections"),
383  cl::Hidden, cl::init(true));
384 
385 // Debug flags.
386 
387 static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
388  cl::init(0));
389 
390 static cl::opt<int> ClDebugStack("asan-debug-stack", cl::desc("debug stack"),
391  cl::Hidden, cl::init(0));
392 
393 static cl::opt<std::string> ClDebugFunc("asan-debug-func", cl::Hidden,
394  cl::desc("Debug func"));
395 
396 static cl::opt<int> ClDebugMin("asan-debug-min", cl::desc("Debug min inst"),
397  cl::Hidden, cl::init(-1));
398 
399 static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug max inst"),
400  cl::Hidden, cl::init(-1));
401 
402 STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
403 STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
404 STATISTIC(NumOptimizedAccessesToGlobalVar,
405  "Number of optimized accesses to global vars");
406 STATISTIC(NumOptimizedAccessesToStackVar,
407  "Number of optimized accesses to stack vars");
408 
409 namespace {
410 
411 /// This struct defines the shadow mapping using the rule:
412 /// shadow = (mem >> Scale) ADD-or-OR Offset.
413 /// If InGlobal is true, then
414 /// extern char __asan_shadow[];
415 /// shadow = (mem >> Scale) + &__asan_shadow
416 struct ShadowMapping {
417  int Scale;
418  uint64_t Offset;
419  bool OrShadowOffset;
420  bool InGlobal;
421 };
422 
423 } // end anonymous namespace
424 
425 static ShadowMapping getShadowMapping(Triple &TargetTriple, int LongSize,
426  bool IsKasan) {
427  bool IsAndroid = TargetTriple.isAndroid();
428  bool IsIOS = TargetTriple.isiOS() || TargetTriple.isWatchOS();
429  bool IsFreeBSD = TargetTriple.isOSFreeBSD();
430  bool IsNetBSD = TargetTriple.isOSNetBSD();
431  bool IsPS4CPU = TargetTriple.isPS4CPU();
432  bool IsLinux = TargetTriple.isOSLinux();
433  bool IsPPC64 = TargetTriple.getArch() == Triple::ppc64 ||
434  TargetTriple.getArch() == Triple::ppc64le;
435  bool IsSystemZ = TargetTriple.getArch() == Triple::systemz;
436  bool IsX86_64 = TargetTriple.getArch() == Triple::x86_64;
437  bool IsMIPS32 = TargetTriple.isMIPS32();
438  bool IsMIPS64 = TargetTriple.isMIPS64();
439  bool IsArmOrThumb = TargetTriple.isARM() || TargetTriple.isThumb();
440  bool IsAArch64 = TargetTriple.getArch() == Triple::aarch64;
441  bool IsWindows = TargetTriple.isOSWindows();
442  bool IsFuchsia = TargetTriple.isOSFuchsia();
443  bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
444  bool IsEmscripten = TargetTriple.isOSEmscripten();
445 
446  ShadowMapping Mapping;
447 
448  Mapping.Scale = IsMyriad ? kMyriadShadowScale : kDefaultShadowScale;
449  if (ClMappingScale.getNumOccurrences() > 0) {
450  Mapping.Scale = ClMappingScale;
451  }
452 
453  if (LongSize == 32) {
454  if (IsAndroid)
455  Mapping.Offset = kDynamicShadowSentinel;
456  else if (IsMIPS32)
457  Mapping.Offset = kMIPS32_ShadowOffset32;
458  else if (IsFreeBSD)
459  Mapping.Offset = kFreeBSD_ShadowOffset32;
460  else if (IsNetBSD)
461  Mapping.Offset = kNetBSD_ShadowOffset32;
462  else if (IsIOS)
463  Mapping.Offset = kDynamicShadowSentinel;
464  else if (IsWindows)
465  Mapping.Offset = kWindowsShadowOffset32;
466  else if (IsEmscripten)
467  Mapping.Offset = kEmscriptenShadowOffset;
468  else if (IsMyriad) {
469  uint64_t ShadowOffset = (kMyriadMemoryOffset32 + kMyriadMemorySize32 -
470  (kMyriadMemorySize32 >> Mapping.Scale));
471  Mapping.Offset = ShadowOffset - (kMyriadMemoryOffset32 >> Mapping.Scale);
472  }
473  else
474  Mapping.Offset = kDefaultShadowOffset32;
475  } else { // LongSize == 64
476  // Fuchsia is always PIE, which means that the beginning of the address
477  // space is always available.
478  if (IsFuchsia)
479  Mapping.Offset = 0;
480  else if (IsPPC64)
481  Mapping.Offset = kPPC64_ShadowOffset64;
482  else if (IsSystemZ)
483  Mapping.Offset = kSystemZ_ShadowOffset64;
484  else if (IsFreeBSD && !IsMIPS64)
485  Mapping.Offset = kFreeBSD_ShadowOffset64;
486  else if (IsNetBSD) {
487  if (IsKasan)
488  Mapping.Offset = kNetBSDKasan_ShadowOffset64;
489  else
490  Mapping.Offset = kNetBSD_ShadowOffset64;
491  } else if (IsPS4CPU)
492  Mapping.Offset = kPS4CPU_ShadowOffset64;
493  else if (IsLinux && IsX86_64) {
494  if (IsKasan)
495  Mapping.Offset = kLinuxKasan_ShadowOffset64;
496  else
497  Mapping.Offset = (kSmallX86_64ShadowOffsetBase &
498  (kSmallX86_64ShadowOffsetAlignMask << Mapping.Scale));
499  } else if (IsWindows && IsX86_64) {
500  Mapping.Offset = kWindowsShadowOffset64;
501  } else if (IsMIPS64)
502  Mapping.Offset = kMIPS64_ShadowOffset64;
503  else if (IsIOS)
504  Mapping.Offset = kDynamicShadowSentinel;
505  else if (IsAArch64)
506  Mapping.Offset = kAArch64_ShadowOffset64;
507  else
508  Mapping.Offset = kDefaultShadowOffset64;
509  }
510 
511  if (ClForceDynamicShadow) {
512  Mapping.Offset = kDynamicShadowSentinel;
513  }
514 
515  if (ClMappingOffset.getNumOccurrences() > 0) {
516  Mapping.Offset = ClMappingOffset;
517  }
518 
519  // OR-ing shadow offset if more efficient (at least on x86) if the offset
520  // is a power of two, but on ppc64 we have to use add since the shadow
521  // offset is not necessary 1/8-th of the address space. On SystemZ,
522  // we could OR the constant in a single instruction, but it's more
523  // efficient to load it once and use indexed addressing.
524  Mapping.OrShadowOffset = !IsAArch64 && !IsPPC64 && !IsSystemZ && !IsPS4CPU &&
525  !(Mapping.Offset & (Mapping.Offset - 1)) &&
526  Mapping.Offset != kDynamicShadowSentinel;
527  bool IsAndroidWithIfuncSupport =
528  IsAndroid && !TargetTriple.isAndroidVersionLT(21);
529  Mapping.InGlobal = ClWithIfunc && IsAndroidWithIfuncSupport && IsArmOrThumb;
530 
531  return Mapping;
532 }
533 
534 static size_t RedzoneSizeForScale(int MappingScale) {
535  // Redzone used for stack and globals is at least 32 bytes.
536  // For scales 6 and 7, the redzone has to be 64 and 128 bytes respectively.
537  return std::max(32U, 1U << MappingScale);
538 }
539 
540 static uint64_t GetCtorAndDtorPriority(Triple &TargetTriple) {
541  if (TargetTriple.isOSEmscripten()) {
543  } else {
545  }
546 }
547 
548 namespace {
549 
550 /// Module analysis for getting various metadata about the module.
551 class ASanGlobalsMetadataWrapperPass : public ModulePass {
552 public:
553  static char ID;
554 
555  ASanGlobalsMetadataWrapperPass() : ModulePass(ID) {
558  }
559 
560  bool runOnModule(Module &M) override {
561  GlobalsMD = GlobalsMetadata(M);
562  return false;
563  }
564 
565  StringRef getPassName() const override {
566  return "ASanGlobalsMetadataWrapperPass";
567  }
568 
569  void getAnalysisUsage(AnalysisUsage &AU) const override {
570  AU.setPreservesAll();
571  }
572 
573  GlobalsMetadata &getGlobalsMD() { return GlobalsMD; }
574 
575 private:
576  GlobalsMetadata GlobalsMD;
577 };
578 
580 
581 /// AddressSanitizer: instrument the code in module to find memory bugs.
582 struct AddressSanitizer {
583  AddressSanitizer(Module &M, GlobalsMetadata &GlobalsMD,
584  bool CompileKernel = false, bool Recover = false,
585  bool UseAfterScope = false)
586  : UseAfterScope(UseAfterScope || ClUseAfterScope), GlobalsMD(GlobalsMD) {
587  this->Recover = ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover;
588  this->CompileKernel =
589  ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan : CompileKernel;
590 
591  C = &(M.getContext());
592  LongSize = M.getDataLayout().getPointerSizeInBits();
593  IntptrTy = Type::getIntNTy(*C, LongSize);
594  TargetTriple = Triple(M.getTargetTriple());
595 
596  Mapping = getShadowMapping(TargetTriple, LongSize, this->CompileKernel);
597  }
598 
599  uint64_t getAllocaSizeInBytes(const AllocaInst &AI) const {
600  uint64_t ArraySize = 1;
601  if (AI.isArrayAllocation()) {
602  const ConstantInt *CI = dyn_cast<ConstantInt>(AI.getArraySize());
603  assert(CI && "non-constant array size");
604  ArraySize = CI->getZExtValue();
605  }
606  Type *Ty = AI.getAllocatedType();
607  uint64_t SizeInBytes =
609  return SizeInBytes * ArraySize;
610  }
611 
612  /// Check if we want (and can) handle this alloca.
613  bool isInterestingAlloca(const AllocaInst &AI);
614 
615  /// If it is an interesting memory access, return the PointerOperand
616  /// and set IsWrite/Alignment. Otherwise return nullptr.
617  /// MaybeMask is an output parameter for the mask Value, if we're looking at a
618  /// masked load/store.
619  Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite,
620  uint64_t *TypeSize, unsigned *Alignment,
621  Value **MaybeMask = nullptr);
622 
623  void instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis, Instruction *I,
624  bool UseCalls, const DataLayout &DL);
625  void instrumentPointerComparisonOrSubtraction(Instruction *I);
626  void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
627  Value *Addr, uint32_t TypeSize, bool IsWrite,
628  Value *SizeArgument, bool UseCalls, uint32_t Exp);
629  void instrumentUnusualSizeOrAlignment(Instruction *I,
630  Instruction *InsertBefore, Value *Addr,
631  uint32_t TypeSize, bool IsWrite,
632  Value *SizeArgument, bool UseCalls,
633  uint32_t Exp);
634  Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
635  Value *ShadowValue, uint32_t TypeSize);
636  Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
637  bool IsWrite, size_t AccessSizeIndex,
638  Value *SizeArgument, uint32_t Exp);
639  void instrumentMemIntrinsic(MemIntrinsic *MI);
640  Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
641  bool instrumentFunction(Function &F, const TargetLibraryInfo *TLI);
642  bool maybeInsertAsanInitAtFunctionEntry(Function &F);
643  void maybeInsertDynamicShadowAtFunctionEntry(Function &F);
644  void markEscapedLocalAllocas(Function &F);
645 
646 private:
647  friend struct FunctionStackPoisoner;
648 
649  void initializeCallbacks(Module &M);
650 
651  bool LooksLikeCodeInBug11395(Instruction *I);
652  bool GlobalIsLinkerInitialized(GlobalVariable *G);
653  bool isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis, Value *Addr,
654  uint64_t TypeSize) const;
655 
656  /// Helper to cleanup per-function state.
657  struct FunctionStateRAII {
659 
660  FunctionStateRAII(AddressSanitizer *Pass) : Pass(Pass) {
661  assert(Pass->ProcessedAllocas.empty() &&
662  "last pass forgot to clear cache");
663  assert(!Pass->LocalDynamicShadow);
664  }
665 
666  ~FunctionStateRAII() {
667  Pass->LocalDynamicShadow = nullptr;
668  Pass->ProcessedAllocas.clear();
669  }
670  };
671 
672  LLVMContext *C;
673  Triple TargetTriple;
674  int LongSize;
675  bool CompileKernel;
676  bool Recover;
677  bool UseAfterScope;
678  Type *IntptrTy;
679  ShadowMapping Mapping;
680  FunctionCallee AsanHandleNoReturnFunc;
681  FunctionCallee AsanPtrCmpFunction, AsanPtrSubFunction;
682  Constant *AsanShadowGlobal;
683 
684  // These arrays is indexed by AccessIsWrite, Experiment and log2(AccessSize).
685  FunctionCallee AsanErrorCallback[2][2][kNumberOfAccessSizes];
686  FunctionCallee AsanMemoryAccessCallback[2][2][kNumberOfAccessSizes];
687 
688  // These arrays is indexed by AccessIsWrite and Experiment.
689  FunctionCallee AsanErrorCallbackSized[2][2];
690  FunctionCallee AsanMemoryAccessCallbackSized[2][2];
691 
692  FunctionCallee AsanMemmove, AsanMemcpy, AsanMemset;
693  InlineAsm *EmptyAsm;
694  Value *LocalDynamicShadow = nullptr;
695  GlobalsMetadata GlobalsMD;
696  DenseMap<const AllocaInst *, bool> ProcessedAllocas;
697 };
698 
699 class AddressSanitizerLegacyPass : public FunctionPass {
700 public:
701  static char ID;
702 
703  explicit AddressSanitizerLegacyPass(bool CompileKernel = false,
704  bool Recover = false,
705  bool UseAfterScope = false)
706  : FunctionPass(ID), CompileKernel(CompileKernel), Recover(Recover),
707  UseAfterScope(UseAfterScope) {
709  }
710 
711  StringRef getPassName() const override {
712  return "AddressSanitizerFunctionPass";
713  }
714 
715  void getAnalysisUsage(AnalysisUsage &AU) const override {
716  AU.addRequired<ASanGlobalsMetadataWrapperPass>();
718  }
719 
720  bool runOnFunction(Function &F) override {
721  GlobalsMetadata &GlobalsMD =
722  getAnalysis<ASanGlobalsMetadataWrapperPass>().getGlobalsMD();
723  const TargetLibraryInfo *TLI =
724  &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F);
725  AddressSanitizer ASan(*F.getParent(), GlobalsMD, CompileKernel, Recover,
726  UseAfterScope);
727  return ASan.instrumentFunction(F, TLI);
728  }
729 
730 private:
731  bool CompileKernel;
732  bool Recover;
733  bool UseAfterScope;
734 };
735 
736 class ModuleAddressSanitizer {
737 public:
738  ModuleAddressSanitizer(Module &M, GlobalsMetadata &GlobalsMD,
739  bool CompileKernel = false, bool Recover = false,
740  bool UseGlobalsGC = true, bool UseOdrIndicator = false)
741  : GlobalsMD(GlobalsMD), UseGlobalsGC(UseGlobalsGC && ClUseGlobalsGC),
742  // Enable aliases as they should have no downside with ODR indicators.
743  UsePrivateAlias(UseOdrIndicator || ClUsePrivateAlias),
744  UseOdrIndicator(UseOdrIndicator || ClUseOdrIndicator),
745  // Not a typo: ClWithComdat is almost completely pointless without
746  // ClUseGlobalsGC (because then it only works on modules without
747  // globals, which are rare); it is a prerequisite for ClUseGlobalsGC;
748  // and both suffer from gold PR19002 for which UseGlobalsGC constructor
749  // argument is designed as workaround. Therefore, disable both
750  // ClWithComdat and ClUseGlobalsGC unless the frontend says it's ok to
751  // do globals-gc.
752  UseCtorComdat(UseGlobalsGC && ClWithComdat) {
753  this->Recover = ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover;
754  this->CompileKernel =
755  ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan : CompileKernel;
756 
757  C = &(M.getContext());
758  int LongSize = M.getDataLayout().getPointerSizeInBits();
759  IntptrTy = Type::getIntNTy(*C, LongSize);
760  TargetTriple = Triple(M.getTargetTriple());
761  Mapping = getShadowMapping(TargetTriple, LongSize, this->CompileKernel);
762  }
763 
764  bool instrumentModule(Module &);
765 
766 private:
767  void initializeCallbacks(Module &M);
768 
769  bool InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat);
770  void InstrumentGlobalsCOFF(IRBuilder<> &IRB, Module &M,
771  ArrayRef<GlobalVariable *> ExtendedGlobals,
772  ArrayRef<Constant *> MetadataInitializers);
773  void InstrumentGlobalsELF(IRBuilder<> &IRB, Module &M,
774  ArrayRef<GlobalVariable *> ExtendedGlobals,
775  ArrayRef<Constant *> MetadataInitializers,
776  const std::string &UniqueModuleId);
777  void InstrumentGlobalsMachO(IRBuilder<> &IRB, Module &M,
778  ArrayRef<GlobalVariable *> ExtendedGlobals,
779  ArrayRef<Constant *> MetadataInitializers);
780  void
781  InstrumentGlobalsWithMetadataArray(IRBuilder<> &IRB, Module &M,
782  ArrayRef<GlobalVariable *> ExtendedGlobals,
783  ArrayRef<Constant *> MetadataInitializers);
784 
785  GlobalVariable *CreateMetadataGlobal(Module &M, Constant *Initializer,
786  StringRef OriginalName);
787  void SetComdatForGlobalMetadata(GlobalVariable *G, GlobalVariable *Metadata,
788  StringRef InternalSuffix);
789  IRBuilder<> CreateAsanModuleDtor(Module &M);
790 
791  bool ShouldInstrumentGlobal(GlobalVariable *G);
792  bool ShouldUseMachOGlobalsSection() const;
793  StringRef getGlobalMetadataSection() const;
794  void poisonOneInitializer(Function &GlobalInit, GlobalValue *ModuleName);
795  void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
796  size_t MinRedzoneSizeForGlobal() const {
797  return RedzoneSizeForScale(Mapping.Scale);
798  }
799  int GetAsanVersion(const Module &M) const;
800 
801  GlobalsMetadata GlobalsMD;
802  bool CompileKernel;
803  bool Recover;
804  bool UseGlobalsGC;
805  bool UsePrivateAlias;
806  bool UseOdrIndicator;
807  bool UseCtorComdat;
808  Type *IntptrTy;
809  LLVMContext *C;
810  Triple TargetTriple;
811  ShadowMapping Mapping;
812  FunctionCallee AsanPoisonGlobals;
813  FunctionCallee AsanUnpoisonGlobals;
814  FunctionCallee AsanRegisterGlobals;
815  FunctionCallee AsanUnregisterGlobals;
816  FunctionCallee AsanRegisterImageGlobals;
817  FunctionCallee AsanUnregisterImageGlobals;
818  FunctionCallee AsanRegisterElfGlobals;
819  FunctionCallee AsanUnregisterElfGlobals;
820 
821  Function *AsanCtorFunction = nullptr;
822  Function *AsanDtorFunction = nullptr;
823 };
824 
825 class ModuleAddressSanitizerLegacyPass : public ModulePass {
826 public:
827  static char ID;
828 
829  explicit ModuleAddressSanitizerLegacyPass(bool CompileKernel = false,
830  bool Recover = false,
831  bool UseGlobalGC = true,
832  bool UseOdrIndicator = false)
833  : ModulePass(ID), CompileKernel(CompileKernel), Recover(Recover),
834  UseGlobalGC(UseGlobalGC), UseOdrIndicator(UseOdrIndicator) {
837  }
838 
839  StringRef getPassName() const override { return "ModuleAddressSanitizer"; }
840 
841  void getAnalysisUsage(AnalysisUsage &AU) const override {
842  AU.addRequired<ASanGlobalsMetadataWrapperPass>();
843  }
844 
845  bool runOnModule(Module &M) override {
846  GlobalsMetadata &GlobalsMD =
847  getAnalysis<ASanGlobalsMetadataWrapperPass>().getGlobalsMD();
848  ModuleAddressSanitizer ASanModule(M, GlobalsMD, CompileKernel, Recover,
849  UseGlobalGC, UseOdrIndicator);
850  return ASanModule.instrumentModule(M);
851  }
852 
853 private:
854  bool CompileKernel;
855  bool Recover;
856  bool UseGlobalGC;
857  bool UseOdrIndicator;
858 };
859 
860 // Stack poisoning does not play well with exception handling.
861 // When an exception is thrown, we essentially bypass the code
862 // that unpoisones the stack. This is why the run-time library has
863 // to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
864 // stack in the interceptor. This however does not work inside the
865 // actual function which catches the exception. Most likely because the
866 // compiler hoists the load of the shadow value somewhere too high.
867 // This causes asan to report a non-existing bug on 453.povray.
868 // It sounds like an LLVM bug.
869 struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
870  Function &F;
871  AddressSanitizer &ASan;
872  DIBuilder DIB;
873  LLVMContext *C;
874  Type *IntptrTy;
875  Type *IntptrPtrTy;
876  ShadowMapping Mapping;
877 
879  SmallVector<AllocaInst *, 16> StaticAllocasToMoveUp;
881  unsigned StackAlignment;
882 
883  FunctionCallee AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
884  AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
885  FunctionCallee AsanSetShadowFunc[0x100] = {};
886  FunctionCallee AsanPoisonStackMemoryFunc, AsanUnpoisonStackMemoryFunc;
887  FunctionCallee AsanAllocaPoisonFunc, AsanAllocasUnpoisonFunc;
888 
889  // Stores a place and arguments of poisoning/unpoisoning call for alloca.
890  struct AllocaPoisonCall {
891  IntrinsicInst *InsBefore;
892  AllocaInst *AI;
893  uint64_t Size;
894  bool DoPoison;
895  };
896  SmallVector<AllocaPoisonCall, 8> DynamicAllocaPoisonCallVec;
897  SmallVector<AllocaPoisonCall, 8> StaticAllocaPoisonCallVec;
898  bool HasUntracedLifetimeIntrinsic = false;
899 
900  SmallVector<AllocaInst *, 1> DynamicAllocaVec;
901  SmallVector<IntrinsicInst *, 1> StackRestoreVec;
902  AllocaInst *DynamicAllocaLayout = nullptr;
903  IntrinsicInst *LocalEscapeCall = nullptr;
904 
905  // Maps Value to an AllocaInst from which the Value is originated.
907  AllocaForValueMapTy AllocaForValue;
908 
909  bool HasNonEmptyInlineAsm = false;
910  bool HasReturnsTwiceCall = false;
911  std::unique_ptr<CallInst> EmptyInlineAsm;
912 
913  FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
914  : F(F), ASan(ASan), DIB(*F.getParent(), /*AllowUnresolved*/ false),
915  C(ASan.C), IntptrTy(ASan.IntptrTy),
916  IntptrPtrTy(PointerType::get(IntptrTy, 0)), Mapping(ASan.Mapping),
917  StackAlignment(1 << Mapping.Scale),
918  EmptyInlineAsm(CallInst::Create(ASan.EmptyAsm)) {}
919 
920  bool runOnFunction() {
921  if (!ClStack) return false;
922 
923  if (ClRedzoneByvalArgs)
924  copyArgsPassedByValToAllocas();
925 
926  // Collect alloca, ret, lifetime instructions etc.
927  for (BasicBlock *BB : depth_first(&F.getEntryBlock())) visit(*BB);
928 
929  if (AllocaVec.empty() && DynamicAllocaVec.empty()) return false;
930 
931  initializeCallbacks(*F.getParent());
932 
933  if (HasUntracedLifetimeIntrinsic) {
934  // If there are lifetime intrinsics which couldn't be traced back to an
935  // alloca, we may not know exactly when a variable enters scope, and
936  // therefore should "fail safe" by not poisoning them.
937  StaticAllocaPoisonCallVec.clear();
938  DynamicAllocaPoisonCallVec.clear();
939  }
940 
941  processDynamicAllocas();
942  processStaticAllocas();
943 
944  if (ClDebugStack) {
945  LLVM_DEBUG(dbgs() << F);
946  }
947  return true;
948  }
949 
950  // Arguments marked with the "byval" attribute are implicitly copied without
951  // using an alloca instruction. To produce redzones for those arguments, we
952  // copy them a second time into memory allocated with an alloca instruction.
953  void copyArgsPassedByValToAllocas();
954 
955  // Finds all Alloca instructions and puts
956  // poisoned red zones around all of them.
957  // Then unpoison everything back before the function returns.
958  void processStaticAllocas();
959  void processDynamicAllocas();
960 
961  void createDynamicAllocasInitStorage();
962 
963  // ----------------------- Visitors.
964  /// Collect all Ret instructions.
965  void visitReturnInst(ReturnInst &RI) { RetVec.push_back(&RI); }
966 
967  /// Collect all Resume instructions.
968  void visitResumeInst(ResumeInst &RI) { RetVec.push_back(&RI); }
969 
970  /// Collect all CatchReturnInst instructions.
971  void visitCleanupReturnInst(CleanupReturnInst &CRI) { RetVec.push_back(&CRI); }
972 
973  void unpoisonDynamicAllocasBeforeInst(Instruction *InstBefore,
974  Value *SavedStack) {
975  IRBuilder<> IRB(InstBefore);
976  Value *DynamicAreaPtr = IRB.CreatePtrToInt(SavedStack, IntptrTy);
977  // When we insert _asan_allocas_unpoison before @llvm.stackrestore, we
978  // need to adjust extracted SP to compute the address of the most recent
979  // alloca. We have a special @llvm.get.dynamic.area.offset intrinsic for
980  // this purpose.
981  if (!isa<ReturnInst>(InstBefore)) {
982  Function *DynamicAreaOffsetFunc = Intrinsic::getDeclaration(
983  InstBefore->getModule(), Intrinsic::get_dynamic_area_offset,
984  {IntptrTy});
985 
986  Value *DynamicAreaOffset = IRB.CreateCall(DynamicAreaOffsetFunc, {});
987 
988  DynamicAreaPtr = IRB.CreateAdd(IRB.CreatePtrToInt(SavedStack, IntptrTy),
989  DynamicAreaOffset);
990  }
991 
992  IRB.CreateCall(
993  AsanAllocasUnpoisonFunc,
994  {IRB.CreateLoad(IntptrTy, DynamicAllocaLayout), DynamicAreaPtr});
995  }
996 
997  // Unpoison dynamic allocas redzones.
998  void unpoisonDynamicAllocas() {
999  for (auto &Ret : RetVec)
1000  unpoisonDynamicAllocasBeforeInst(Ret, DynamicAllocaLayout);
1001 
1002  for (auto &StackRestoreInst : StackRestoreVec)
1003  unpoisonDynamicAllocasBeforeInst(StackRestoreInst,
1004  StackRestoreInst->getOperand(0));
1005  }
1006 
1007  // Deploy and poison redzones around dynamic alloca call. To do this, we
1008  // should replace this call with another one with changed parameters and
1009  // replace all its uses with new address, so
1010  // addr = alloca type, old_size, align
1011  // is replaced by
1012  // new_size = (old_size + additional_size) * sizeof(type)
1013  // tmp = alloca i8, new_size, max(align, 32)
1014  // addr = tmp + 32 (first 32 bytes are for the left redzone).
1015  // Additional_size is added to make new memory allocation contain not only
1016  // requested memory, but also left, partial and right redzones.
1017  void handleDynamicAllocaCall(AllocaInst *AI);
1018 
1019  /// Collect Alloca instructions we want (and can) handle.
1020  void visitAllocaInst(AllocaInst &AI) {
1021  if (!ASan.isInterestingAlloca(AI)) {
1022  if (AI.isStaticAlloca()) {
1023  // Skip over allocas that are present *before* the first instrumented
1024  // alloca, we don't want to move those around.
1025  if (AllocaVec.empty())
1026  return;
1027 
1028  StaticAllocasToMoveUp.push_back(&AI);
1029  }
1030  return;
1031  }
1032 
1033  StackAlignment = std::max(StackAlignment, AI.getAlignment());
1034  if (!AI.isStaticAlloca())
1035  DynamicAllocaVec.push_back(&AI);
1036  else
1037  AllocaVec.push_back(&AI);
1038  }
1039 
1040  /// Collect lifetime intrinsic calls to check for use-after-scope
1041  /// errors.
1042  void visitIntrinsicInst(IntrinsicInst &II) {
1044  if (ID == Intrinsic::stackrestore) StackRestoreVec.push_back(&II);
1045  if (ID == Intrinsic::localescape) LocalEscapeCall = &II;
1046  if (!ASan.UseAfterScope)
1047  return;
1048  if (!II.isLifetimeStartOrEnd())
1049  return;
1050  // Found lifetime intrinsic, add ASan instrumentation if necessary.
1052  // If size argument is undefined, don't do anything.
1053  if (Size->isMinusOne()) return;
1054  // Check that size doesn't saturate uint64_t and can
1055  // be stored in IntptrTy.
1056  const uint64_t SizeValue = Size->getValue().getLimitedValue();
1057  if (SizeValue == ~0ULL ||
1058  !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
1059  return;
1060  // Find alloca instruction that corresponds to llvm.lifetime argument.
1061  AllocaInst *AI =
1062  llvm::findAllocaForValue(II.getArgOperand(1), AllocaForValue);
1063  if (!AI) {
1064  HasUntracedLifetimeIntrinsic = true;
1065  return;
1066  }
1067  // We're interested only in allocas we can handle.
1068  if (!ASan.isInterestingAlloca(*AI))
1069  return;
1070  bool DoPoison = (ID == Intrinsic::lifetime_end);
1071  AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
1072  if (AI->isStaticAlloca())
1073  StaticAllocaPoisonCallVec.push_back(APC);
1074  else if (ClInstrumentDynamicAllocas)
1075  DynamicAllocaPoisonCallVec.push_back(APC);
1076  }
1077 
1078  void visitCallSite(CallSite CS) {
1079  Instruction *I = CS.getInstruction();
1080  if (CallInst *CI = dyn_cast<CallInst>(I)) {
1081  HasNonEmptyInlineAsm |= CI->isInlineAsm() &&
1082  !CI->isIdenticalTo(EmptyInlineAsm.get()) &&
1083  I != ASan.LocalDynamicShadow;
1084  HasReturnsTwiceCall |= CI->canReturnTwice();
1085  }
1086  }
1087 
1088  // ---------------------- Helpers.
1089  void initializeCallbacks(Module &M);
1090 
1091  // Copies bytes from ShadowBytes into shadow memory for indexes where
1092  // ShadowMask is not zero. If ShadowMask[i] is zero, we assume that
1093  // ShadowBytes[i] is constantly zero and doesn't need to be overwritten.
1094  void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1095  IRBuilder<> &IRB, Value *ShadowBase);
1096  void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1097  size_t Begin, size_t End, IRBuilder<> &IRB,
1098  Value *ShadowBase);
1099  void copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
1100  ArrayRef<uint8_t> ShadowBytes, size_t Begin,
1101  size_t End, IRBuilder<> &IRB, Value *ShadowBase);
1102 
1103  void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
1104 
1105  Value *createAllocaForLayout(IRBuilder<> &IRB, const ASanStackFrameLayout &L,
1106  bool Dynamic);
1107  PHINode *createPHI(IRBuilder<> &IRB, Value *Cond, Value *ValueIfTrue,
1108  Instruction *ThenTerm, Value *ValueIfFalse);
1109 };
1110 
1111 } // end anonymous namespace
1112 
1114  assert(MDN->getNumOperands() == 3);
1115  MDString *DIFilename = cast<MDString>(MDN->getOperand(0));
1116  Filename = DIFilename->getString();
1117  LineNo = mdconst::extract<ConstantInt>(MDN->getOperand(1))->getLimitedValue();
1118  ColumnNo =
1119  mdconst::extract<ConstantInt>(MDN->getOperand(2))->getLimitedValue();
1120 }
1121 
1122 // FIXME: It would be cleaner to instead attach relevant metadata to the globals
1123 // we want to sanitize instead and reading this metadata on each pass over a
1124 // function instead of reading module level metadata at first.
1126  NamedMDNode *Globals = M.getNamedMetadata("llvm.asan.globals");
1127  if (!Globals)
1128  return;
1129  for (auto MDN : Globals->operands()) {
1130  // Metadata node contains the global and the fields of "Entry".
1131  assert(MDN->getNumOperands() == 5);
1132  auto *V = mdconst::extract_or_null<Constant>(MDN->getOperand(0));
1133  // The optimizer may optimize away a global entirely.
1134  if (!V)
1135  continue;
1136  auto *StrippedV = V->stripPointerCasts();
1137  auto *GV = dyn_cast<GlobalVariable>(StrippedV);
1138  if (!GV)
1139  continue;
1140  // We can already have an entry for GV if it was merged with another
1141  // global.
1142  Entry &E = Entries[GV];
1143  if (auto *Loc = cast_or_null<MDNode>(MDN->getOperand(1)))
1144  E.SourceLoc.parse(Loc);
1145  if (auto *Name = cast_or_null<MDString>(MDN->getOperand(2)))
1146  E.Name = Name->getString();
1147  ConstantInt *IsDynInit = mdconst::extract<ConstantInt>(MDN->getOperand(3));
1148  E.IsDynInit |= IsDynInit->isOne();
1149  ConstantInt *IsBlacklisted =
1150  mdconst::extract<ConstantInt>(MDN->getOperand(4));
1151  E.IsBlacklisted |= IsBlacklisted->isOne();
1152  }
1153 }
1154 
1155 AnalysisKey ASanGlobalsMetadataAnalysis::Key;
1156 
1158  ModuleAnalysisManager &AM) {
1159  return GlobalsMetadata(M);
1160 }
1161 
1162 AddressSanitizerPass::AddressSanitizerPass(bool CompileKernel, bool Recover,
1163  bool UseAfterScope)
1164  : CompileKernel(CompileKernel), Recover(Recover),
1165  UseAfterScope(UseAfterScope) {}
1166 
1169  auto &MAMProxy = AM.getResult<ModuleAnalysisManagerFunctionProxy>(F);
1170  auto &MAM = MAMProxy.getManager();
1171  Module &M = *F.getParent();
1172  if (auto *R = MAM.getCachedResult<ASanGlobalsMetadataAnalysis>(M)) {
1174  AddressSanitizer Sanitizer(M, *R, CompileKernel, Recover, UseAfterScope);
1175  if (Sanitizer.instrumentFunction(F, TLI))
1176  return PreservedAnalyses::none();
1177  return PreservedAnalyses::all();
1178  }
1179 
1181  "The ASanGlobalsMetadataAnalysis is required to run before "
1182  "AddressSanitizer can run");
1183  return PreservedAnalyses::all();
1184 }
1185 
1187  bool Recover,
1188  bool UseGlobalGC,
1189  bool UseOdrIndicator)
1190  : CompileKernel(CompileKernel), Recover(Recover), UseGlobalGC(UseGlobalGC),
1191  UseOdrIndicator(UseOdrIndicator) {}
1192 
1196  ModuleAddressSanitizer Sanitizer(M, GlobalsMD, CompileKernel, Recover,
1197  UseGlobalGC, UseOdrIndicator);
1198  if (Sanitizer.instrumentModule(M))
1199  return PreservedAnalyses::none();
1200  return PreservedAnalyses::all();
1201 }
1202 
1203 INITIALIZE_PASS(ASanGlobalsMetadataWrapperPass, "asan-globals-md",
1204  "Read metadata to mark which globals should be instrumented "
1205  "when running ASan.",
1206  false, true)
1207 
1209 
1211  AddressSanitizerLegacyPass, "asan",
1212  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,
1213  false)
1214 INITIALIZE_PASS_DEPENDENCY(ASanGlobalsMetadataWrapperPass)
1217  AddressSanitizerLegacyPass, "asan",
1218  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,
1219  false)
1220 
1222  bool Recover,
1223  bool UseAfterScope) {
1224  assert(!CompileKernel || Recover);
1225  return new AddressSanitizerLegacyPass(CompileKernel, Recover, UseAfterScope);
1226 }
1227 
1229 
1231  ModuleAddressSanitizerLegacyPass, "asan-module",
1232  "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
1233  "ModulePass",
1234  false, false)
1235 
1237  bool CompileKernel, bool Recover, bool UseGlobalsGC, bool UseOdrIndicator) {
1238  assert(!CompileKernel || Recover);
1239  return new ModuleAddressSanitizerLegacyPass(CompileKernel, Recover,
1240  UseGlobalsGC, UseOdrIndicator);
1241 }
1242 
1243 static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
1244  size_t Res = countTrailingZeros(TypeSize / 8);
1246  return Res;
1247 }
1248 
1249 /// Create a global describing a source location.
1251  LocationMetadata MD) {
1252  Constant *LocData[] = {
1253  createPrivateGlobalForString(M, MD.Filename, true, kAsanGenPrefix),
1256  };
1257  auto LocStruct = ConstantStruct::getAnon(LocData);
1258  auto GV = new GlobalVariable(M, LocStruct->getType(), true,
1259  GlobalValue::PrivateLinkage, LocStruct,
1260  kAsanGenPrefix);
1262  return GV;
1263 }
1264 
1265 /// Check if \p G has been created by a trusted compiler pass.
1267  // Do not instrument @llvm.global_ctors, @llvm.used, etc.
1268  if (G->getName().startswith("llvm."))
1269  return true;
1270 
1271  // Do not instrument asan globals.
1272  if (G->getName().startswith(kAsanGenPrefix) ||
1273  G->getName().startswith(kSanCovGenPrefix) ||
1274  G->getName().startswith(kODRGenPrefix))
1275  return true;
1276 
1277  // Do not instrument gcov counter arrays.
1278  if (G->getName() == "__llvm_gcov_ctr")
1279  return true;
1280 
1281  return false;
1282 }
1283 
1284 Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
1285  // Shadow >> scale
1286  Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
1287  if (Mapping.Offset == 0) return Shadow;
1288  // (Shadow >> scale) | offset
1289  Value *ShadowBase;
1290  if (LocalDynamicShadow)
1291  ShadowBase = LocalDynamicShadow;
1292  else
1293  ShadowBase = ConstantInt::get(IntptrTy, Mapping.Offset);
1294  if (Mapping.OrShadowOffset)
1295  return IRB.CreateOr(Shadow, ShadowBase);
1296  else
1297  return IRB.CreateAdd(Shadow, ShadowBase);
1298 }
1299 
1300 // Instrument memset/memmove/memcpy
1301 void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
1302  IRBuilder<> IRB(MI);
1303  if (isa<MemTransferInst>(MI)) {
1304  IRB.CreateCall(
1305  isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
1306  {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1307  IRB.CreatePointerCast(MI->getOperand(1), IRB.getInt8PtrTy()),
1308  IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1309  } else if (isa<MemSetInst>(MI)) {
1310  IRB.CreateCall(
1311  AsanMemset,
1312  {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1313  IRB.CreateIntCast(MI->getOperand(1), IRB.getInt32Ty(), false),
1314  IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1315  }
1316  MI->eraseFromParent();
1317 }
1318 
1319 /// Check if we want (and can) handle this alloca.
1320 bool AddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
1321  auto PreviouslySeenAllocaInfo = ProcessedAllocas.find(&AI);
1322 
1323  if (PreviouslySeenAllocaInfo != ProcessedAllocas.end())
1324  return PreviouslySeenAllocaInfo->getSecond();
1325 
1326  bool IsInteresting =
1327  (AI.getAllocatedType()->isSized() &&
1328  // alloca() may be called with 0 size, ignore it.
1329  ((!AI.isStaticAlloca()) || getAllocaSizeInBytes(AI) > 0) &&
1330  // We are only interested in allocas not promotable to registers.
1331  // Promotable allocas are common under -O0.
1333  // inalloca allocas are not treated as static, and we don't want
1334  // dynamic alloca instrumentation for them as well.
1335  !AI.isUsedWithInAlloca() &&
1336  // swifterror allocas are register promoted by ISel
1337  !AI.isSwiftError());
1338 
1339  ProcessedAllocas[&AI] = IsInteresting;
1340  return IsInteresting;
1341 }
1342 
1343 Value *AddressSanitizer::isInterestingMemoryAccess(Instruction *I,
1344  bool *IsWrite,
1345  uint64_t *TypeSize,
1346  unsigned *Alignment,
1347  Value **MaybeMask) {
1348  // Skip memory accesses inserted by another instrumentation.
1349  if (I->hasMetadata("nosanitize")) return nullptr;
1350 
1351  // Do not instrument the load fetching the dynamic shadow address.
1352  if (LocalDynamicShadow == I)
1353  return nullptr;
1354 
1355  Value *PtrOperand = nullptr;
1356  const DataLayout &DL = I->getModule()->getDataLayout();
1357  if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
1358  if (!ClInstrumentReads) return nullptr;
1359  *IsWrite = false;
1360  *TypeSize = DL.getTypeStoreSizeInBits(LI->getType());
1361  *Alignment = LI->getAlignment();
1362  PtrOperand = LI->getPointerOperand();
1363  } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
1364  if (!ClInstrumentWrites) return nullptr;
1365  *IsWrite = true;
1366  *TypeSize = DL.getTypeStoreSizeInBits(SI->getValueOperand()->getType());
1367  *Alignment = SI->getAlignment();
1368  PtrOperand = SI->getPointerOperand();
1369  } else if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
1370  if (!ClInstrumentAtomics) return nullptr;
1371  *IsWrite = true;
1372  *TypeSize = DL.getTypeStoreSizeInBits(RMW->getValOperand()->getType());
1373  *Alignment = 0;
1374  PtrOperand = RMW->getPointerOperand();
1375  } else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
1376  if (!ClInstrumentAtomics) return nullptr;
1377  *IsWrite = true;
1378  *TypeSize = DL.getTypeStoreSizeInBits(XCHG->getCompareOperand()->getType());
1379  *Alignment = 0;
1380  PtrOperand = XCHG->getPointerOperand();
1381  } else if (auto CI = dyn_cast<CallInst>(I)) {
1382  auto *F = dyn_cast<Function>(CI->getCalledValue());
1383  if (F && (F->getName().startswith("llvm.masked.load.") ||
1384  F->getName().startswith("llvm.masked.store."))) {
1385  unsigned OpOffset = 0;
1386  if (F->getName().startswith("llvm.masked.store.")) {
1387  if (!ClInstrumentWrites)
1388  return nullptr;
1389  // Masked store has an initial operand for the value.
1390  OpOffset = 1;
1391  *IsWrite = true;
1392  } else {
1393  if (!ClInstrumentReads)
1394  return nullptr;
1395  *IsWrite = false;
1396  }
1397 
1398  auto BasePtr = CI->getOperand(0 + OpOffset);
1399  auto Ty = cast<PointerType>(BasePtr->getType())->getElementType();
1400  *TypeSize = DL.getTypeStoreSizeInBits(Ty);
1401  if (auto AlignmentConstant =
1402  dyn_cast<ConstantInt>(CI->getOperand(1 + OpOffset)))
1403  *Alignment = (unsigned)AlignmentConstant->getZExtValue();
1404  else
1405  *Alignment = 1; // No alignment guarantees. We probably got Undef
1406  if (MaybeMask)
1407  *MaybeMask = CI->getOperand(2 + OpOffset);
1408  PtrOperand = BasePtr;
1409  }
1410  }
1411 
1412  if (PtrOperand) {
1413  // Do not instrument acesses from different address spaces; we cannot deal
1414  // with them.
1415  Type *PtrTy = cast<PointerType>(PtrOperand->getType()->getScalarType());
1416  if (PtrTy->getPointerAddressSpace() != 0)
1417  return nullptr;
1418 
1419  // Ignore swifterror addresses.
1420  // swifterror memory addresses are mem2reg promoted by instruction
1421  // selection. As such they cannot have regular uses like an instrumentation
1422  // function and it makes no sense to track them as memory.
1423  if (PtrOperand->isSwiftError())
1424  return nullptr;
1425  }
1426 
1427  // Treat memory accesses to promotable allocas as non-interesting since they
1428  // will not cause memory violations. This greatly speeds up the instrumented
1429  // executable at -O0.
1431  if (auto AI = dyn_cast_or_null<AllocaInst>(PtrOperand))
1432  return isInterestingAlloca(*AI) ? AI : nullptr;
1433 
1434  return PtrOperand;
1435 }
1436 
1437 static bool isPointerOperand(Value *V) {
1438  return V->getType()->isPointerTy() || isa<PtrToIntInst>(V);
1439 }
1440 
1441 // This is a rough heuristic; it may cause both false positives and
1442 // false negatives. The proper implementation requires cooperation with
1443 // the frontend.
1445  if (ICmpInst *Cmp = dyn_cast<ICmpInst>(I)) {
1446  if (!Cmp->isRelational())
1447  return false;
1448  } else {
1449  return false;
1450  }
1451  return isPointerOperand(I->getOperand(0)) &&
1453 }
1454 
1455 // This is a rough heuristic; it may cause both false positives and
1456 // false negatives. The proper implementation requires cooperation with
1457 // the frontend.
1459  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) {
1460  if (BO->getOpcode() != Instruction::Sub)
1461  return false;
1462  } else {
1463  return false;
1464  }
1465  return isPointerOperand(I->getOperand(0)) &&
1467 }
1468 
1469 bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
1470  // If a global variable does not have dynamic initialization we don't
1471  // have to instrument it. However, if a global does not have initializer
1472  // at all, we assume it has dynamic initializer (in other TU).
1473  //
1474  // FIXME: Metadata should be attched directly to the global directly instead
1475  // of being added to llvm.asan.globals.
1476  return G->hasInitializer() && !GlobalsMD.get(G).IsDynInit;
1477 }
1478 
1479 void AddressSanitizer::instrumentPointerComparisonOrSubtraction(
1480  Instruction *I) {
1481  IRBuilder<> IRB(I);
1482  FunctionCallee F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
1483  Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
1484  for (Value *&i : Param) {
1485  if (i->getType()->isPointerTy())
1486  i = IRB.CreatePointerCast(i, IntptrTy);
1487  }
1488  IRB.CreateCall(F, Param);
1489 }
1490 
1492  Instruction *InsertBefore, Value *Addr,
1493  unsigned Alignment, unsigned Granularity,
1494  uint32_t TypeSize, bool IsWrite,
1495  Value *SizeArgument, bool UseCalls,
1496  uint32_t Exp) {
1497  // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check
1498  // if the data is properly aligned.
1499  if ((TypeSize == 8 || TypeSize == 16 || TypeSize == 32 || TypeSize == 64 ||
1500  TypeSize == 128) &&
1501  (Alignment >= Granularity || Alignment == 0 || Alignment >= TypeSize / 8))
1502  return Pass->instrumentAddress(I, InsertBefore, Addr, TypeSize, IsWrite,
1503  nullptr, UseCalls, Exp);
1504  Pass->instrumentUnusualSizeOrAlignment(I, InsertBefore, Addr, TypeSize,
1505  IsWrite, nullptr, UseCalls, Exp);
1506 }
1507 
1509  const DataLayout &DL, Type *IntptrTy,
1510  Value *Mask, Instruction *I,
1511  Value *Addr, unsigned Alignment,
1512  unsigned Granularity, uint32_t TypeSize,
1513  bool IsWrite, Value *SizeArgument,
1514  bool UseCalls, uint32_t Exp) {
1515  auto *VTy = cast<PointerType>(Addr->getType())->getElementType();
1516  uint64_t ElemTypeSize = DL.getTypeStoreSizeInBits(VTy->getScalarType());
1517  unsigned Num = VTy->getVectorNumElements();
1518  auto Zero = ConstantInt::get(IntptrTy, 0);
1519  for (unsigned Idx = 0; Idx < Num; ++Idx) {
1520  Value *InstrumentedAddress = nullptr;
1521  Instruction *InsertBefore = I;
1522  if (auto *Vector = dyn_cast<ConstantVector>(Mask)) {
1523  // dyn_cast as we might get UndefValue
1524  if (auto *Masked = dyn_cast<ConstantInt>(Vector->getOperand(Idx))) {
1525  if (Masked->isZero())
1526  // Mask is constant false, so no instrumentation needed.
1527  continue;
1528  // If we have a true or undef value, fall through to doInstrumentAddress
1529  // with InsertBefore == I
1530  }
1531  } else {
1532  IRBuilder<> IRB(I);
1533  Value *MaskElem = IRB.CreateExtractElement(Mask, Idx);
1534  Instruction *ThenTerm = SplitBlockAndInsertIfThen(MaskElem, I, false);
1535  InsertBefore = ThenTerm;
1536  }
1537 
1538  IRBuilder<> IRB(InsertBefore);
1539  InstrumentedAddress =
1540  IRB.CreateGEP(VTy, Addr, {Zero, ConstantInt::get(IntptrTy, Idx)});
1541  doInstrumentAddress(Pass, I, InsertBefore, InstrumentedAddress, Alignment,
1542  Granularity, ElemTypeSize, IsWrite, SizeArgument,
1543  UseCalls, Exp);
1544  }
1545 }
1546 
1547 void AddressSanitizer::instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
1548  Instruction *I, bool UseCalls,
1549  const DataLayout &DL) {
1550  bool IsWrite = false;
1551  unsigned Alignment = 0;
1552  uint64_t TypeSize = 0;
1553  Value *MaybeMask = nullptr;
1554  Value *Addr =
1555  isInterestingMemoryAccess(I, &IsWrite, &TypeSize, &Alignment, &MaybeMask);
1556  assert(Addr);
1557 
1558  // Optimization experiments.
1559  // The experiments can be used to evaluate potential optimizations that remove
1560  // instrumentation (assess false negatives). Instead of completely removing
1561  // some instrumentation, you set Exp to a non-zero value (mask of optimization
1562  // experiments that want to remove instrumentation of this instruction).
1563  // If Exp is non-zero, this pass will emit special calls into runtime
1564  // (e.g. __asan_report_exp_load1 instead of __asan_report_load1). These calls
1565  // make runtime terminate the program in a special way (with a different
1566  // exit status). Then you run the new compiler on a buggy corpus, collect
1567  // the special terminations (ideally, you don't see them at all -- no false
1568  // negatives) and make the decision on the optimization.
1570 
1571  if (ClOpt && ClOptGlobals) {
1572  // If initialization order checking is disabled, a simple access to a
1573  // dynamically initialized global is always valid.
1575  if (G && (!ClInitializers || GlobalIsLinkerInitialized(G)) &&
1576  isSafeAccess(ObjSizeVis, Addr, TypeSize)) {
1577  NumOptimizedAccessesToGlobalVar++;
1578  return;
1579  }
1580  }
1581 
1582  if (ClOpt && ClOptStack) {
1583  // A direct inbounds access to a stack variable is always valid.
1584  if (isa<AllocaInst>(GetUnderlyingObject(Addr, DL)) &&
1585  isSafeAccess(ObjSizeVis, Addr, TypeSize)) {
1586  NumOptimizedAccessesToStackVar++;
1587  return;
1588  }
1589  }
1590 
1591  if (IsWrite)
1592  NumInstrumentedWrites++;
1593  else
1594  NumInstrumentedReads++;
1595 
1596  unsigned Granularity = 1 << Mapping.Scale;
1597  if (MaybeMask) {
1598  instrumentMaskedLoadOrStore(this, DL, IntptrTy, MaybeMask, I, Addr,
1599  Alignment, Granularity, TypeSize, IsWrite,
1600  nullptr, UseCalls, Exp);
1601  } else {
1602  doInstrumentAddress(this, I, I, Addr, Alignment, Granularity, TypeSize,
1603  IsWrite, nullptr, UseCalls, Exp);
1604  }
1605 }
1606 
1607 Instruction *AddressSanitizer::generateCrashCode(Instruction *InsertBefore,
1608  Value *Addr, bool IsWrite,
1609  size_t AccessSizeIndex,
1610  Value *SizeArgument,
1611  uint32_t Exp) {
1612  IRBuilder<> IRB(InsertBefore);
1613  Value *ExpVal = Exp == 0 ? nullptr : ConstantInt::get(IRB.getInt32Ty(), Exp);
1614  CallInst *Call = nullptr;
1615  if (SizeArgument) {
1616  if (Exp == 0)
1617  Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][0],
1618  {Addr, SizeArgument});
1619  else
1620  Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][1],
1621  {Addr, SizeArgument, ExpVal});
1622  } else {
1623  if (Exp == 0)
1624  Call =
1625  IRB.CreateCall(AsanErrorCallback[IsWrite][0][AccessSizeIndex], Addr);
1626  else
1627  Call = IRB.CreateCall(AsanErrorCallback[IsWrite][1][AccessSizeIndex],
1628  {Addr, ExpVal});
1629  }
1630 
1631  // We don't do Call->setDoesNotReturn() because the BB already has
1632  // UnreachableInst at the end.
1633  // This EmptyAsm is required to avoid callback merge.
1634  IRB.CreateCall(EmptyAsm, {});
1635  return Call;
1636 }
1637 
1638 Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
1639  Value *ShadowValue,
1640  uint32_t TypeSize) {
1641  size_t Granularity = static_cast<size_t>(1) << Mapping.Scale;
1642  // Addr & (Granularity - 1)
1643  Value *LastAccessedByte =
1644  IRB.CreateAnd(AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
1645  // (Addr & (Granularity - 1)) + size - 1
1646  if (TypeSize / 8 > 1)
1647  LastAccessedByte = IRB.CreateAdd(
1648  LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1));
1649  // (uint8_t) ((Addr & (Granularity-1)) + size - 1)
1650  LastAccessedByte =
1651  IRB.CreateIntCast(LastAccessedByte, ShadowValue->getType(), false);
1652  // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
1653  return IRB.CreateICmpSGE(LastAccessedByte, ShadowValue);
1654 }
1655 
1656 void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
1657  Instruction *InsertBefore, Value *Addr,
1658  uint32_t TypeSize, bool IsWrite,
1659  Value *SizeArgument, bool UseCalls,
1660  uint32_t Exp) {
1661  bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
1662 
1663  IRBuilder<> IRB(InsertBefore);
1664  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1665  size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
1666 
1667  if (UseCalls) {
1668  if (Exp == 0)
1669  IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][0][AccessSizeIndex],
1670  AddrLong);
1671  else
1672  IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][1][AccessSizeIndex],
1673  {AddrLong, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1674  return;
1675  }
1676 
1677  if (IsMyriad) {
1678  // Strip the cache bit and do range check.
1679  // AddrLong &= ~kMyriadCacheBitMask32
1680  AddrLong = IRB.CreateAnd(AddrLong, ~kMyriadCacheBitMask32);
1681  // Tag = AddrLong >> kMyriadTagShift
1682  Value *Tag = IRB.CreateLShr(AddrLong, kMyriadTagShift);
1683  // Tag == kMyriadDDRTag
1684  Value *TagCheck =
1685  IRB.CreateICmpEQ(Tag, ConstantInt::get(IntptrTy, kMyriadDDRTag));
1686 
1687  Instruction *TagCheckTerm =
1688  SplitBlockAndInsertIfThen(TagCheck, InsertBefore, false,
1689  MDBuilder(*C).createBranchWeights(1, 100000));
1690  assert(cast<BranchInst>(TagCheckTerm)->isUnconditional());
1691  IRB.SetInsertPoint(TagCheckTerm);
1692  InsertBefore = TagCheckTerm;
1693  }
1694 
1695  Type *ShadowTy =
1696  IntegerType::get(*C, std::max(8U, TypeSize >> Mapping.Scale));
1697  Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
1698  Value *ShadowPtr = memToShadow(AddrLong, IRB);
1699  Value *CmpVal = Constant::getNullValue(ShadowTy);
1700  Value *ShadowValue =
1701  IRB.CreateLoad(ShadowTy, IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));
1702 
1703  Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
1704  size_t Granularity = 1ULL << Mapping.Scale;
1705  Instruction *CrashTerm = nullptr;
1706 
1707  if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
1708  // We use branch weights for the slow path check, to indicate that the slow
1709  // path is rarely taken. This seems to be the case for SPEC benchmarks.
1711  Cmp, InsertBefore, false, MDBuilder(*C).createBranchWeights(1, 100000));
1712  assert(cast<BranchInst>(CheckTerm)->isUnconditional());
1713  BasicBlock *NextBB = CheckTerm->getSuccessor(0);
1714  IRB.SetInsertPoint(CheckTerm);
1715  Value *Cmp2 = createSlowPathCmp(IRB, AddrLong, ShadowValue, TypeSize);
1716  if (Recover) {
1717  CrashTerm = SplitBlockAndInsertIfThen(Cmp2, CheckTerm, false);
1718  } else {
1719  BasicBlock *CrashBlock =
1720  BasicBlock::Create(*C, "", NextBB->getParent(), NextBB);
1721  CrashTerm = new UnreachableInst(*C, CrashBlock);
1722  BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
1723  ReplaceInstWithInst(CheckTerm, NewTerm);
1724  }
1725  } else {
1726  CrashTerm = SplitBlockAndInsertIfThen(Cmp, InsertBefore, !Recover);
1727  }
1728 
1729  Instruction *Crash = generateCrashCode(CrashTerm, AddrLong, IsWrite,
1730  AccessSizeIndex, SizeArgument, Exp);
1731  Crash->setDebugLoc(OrigIns->getDebugLoc());
1732 }
1733 
1734 // Instrument unusual size or unusual alignment.
1735 // We can not do it with a single check, so we do 1-byte check for the first
1736 // and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
1737 // to report the actual access size.
1738 void AddressSanitizer::instrumentUnusualSizeOrAlignment(
1739  Instruction *I, Instruction *InsertBefore, Value *Addr, uint32_t TypeSize,
1740  bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp) {
1741  IRBuilder<> IRB(InsertBefore);
1742  Value *Size = ConstantInt::get(IntptrTy, TypeSize / 8);
1743  Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1744  if (UseCalls) {
1745  if (Exp == 0)
1746  IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][0],
1747  {AddrLong, Size});
1748  else
1749  IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][1],
1750  {AddrLong, Size, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1751  } else {
1752  Value *LastByte = IRB.CreateIntToPtr(
1753  IRB.CreateAdd(AddrLong, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
1754  Addr->getType());
1755  instrumentAddress(I, InsertBefore, Addr, 8, IsWrite, Size, false, Exp);
1756  instrumentAddress(I, InsertBefore, LastByte, 8, IsWrite, Size, false, Exp);
1757  }
1758 }
1759 
1760 void ModuleAddressSanitizer::poisonOneInitializer(Function &GlobalInit,
1761  GlobalValue *ModuleName) {
1762  // Set up the arguments to our poison/unpoison functions.
1763  IRBuilder<> IRB(&GlobalInit.front(),
1764  GlobalInit.front().getFirstInsertionPt());
1765 
1766  // Add a call to poison all external globals before the given function starts.
1767  Value *ModuleNameAddr = ConstantExpr::getPointerCast(ModuleName, IntptrTy);
1768  IRB.CreateCall(AsanPoisonGlobals, ModuleNameAddr);
1769 
1770  // Add calls to unpoison all globals before each return instruction.
1771  for (auto &BB : GlobalInit.getBasicBlockList())
1772  if (ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator()))
1773  CallInst::Create(AsanUnpoisonGlobals, "", RI);
1774 }
1775 
1776 void ModuleAddressSanitizer::createInitializerPoisonCalls(
1777  Module &M, GlobalValue *ModuleName) {
1778  GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
1779  if (!GV)
1780  return;
1781 
1783  if (!CA)
1784  return;
1785 
1786  for (Use &OP : CA->operands()) {
1787  if (isa<ConstantAggregateZero>(OP)) continue;
1788  ConstantStruct *CS = cast<ConstantStruct>(OP);
1789 
1790  // Must have a function or null ptr.
1791  if (Function *F = dyn_cast<Function>(CS->getOperand(1))) {
1792  if (F->getName() == kAsanModuleCtorName) continue;
1793  ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1794  // Don't instrument CTORs that will run before asan.module_ctor.
1795  if (Priority->getLimitedValue() <= GetCtorAndDtorPriority(TargetTriple))
1796  continue;
1797  poisonOneInitializer(*F, ModuleName);
1798  }
1799  }
1800 }
1801 
1802 bool ModuleAddressSanitizer::ShouldInstrumentGlobal(GlobalVariable *G) {
1803  Type *Ty = G->getValueType();
1804  LLVM_DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
1805 
1806  // FIXME: Metadata should be attched directly to the global directly instead
1807  // of being added to llvm.asan.globals.
1808  if (GlobalsMD.get(G).IsBlacklisted) return false;
1809  if (!Ty->isSized()) return false;
1810  if (!G->hasInitializer()) return false;
1811  if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
1812  // Two problems with thread-locals:
1813  // - The address of the main thread's copy can't be computed at link-time.
1814  // - Need to poison all copies, not just the main thread's one.
1815  if (G->isThreadLocal()) return false;
1816  // For now, just ignore this Global if the alignment is large.
1817  if (G->getAlignment() > MinRedzoneSizeForGlobal()) return false;
1818 
1819  // For non-COFF targets, only instrument globals known to be defined by this
1820  // TU.
1821  // FIXME: We can instrument comdat globals on ELF if we are using the
1822  // GC-friendly metadata scheme.
1823  if (!TargetTriple.isOSBinFormatCOFF()) {
1824  if (!G->hasExactDefinition() || G->hasComdat())
1825  return false;
1826  } else {
1827  // On COFF, don't instrument non-ODR linkages.
1828  if (G->isInterposable())
1829  return false;
1830  }
1831 
1832  // If a comdat is present, it must have a selection kind that implies ODR
1833  // semantics: no duplicates, any, or exact match.
1834  if (Comdat *C = G->getComdat()) {
1835  switch (C->getSelectionKind()) {
1836  case Comdat::Any:
1837  case Comdat::ExactMatch:
1838  case Comdat::NoDuplicates:
1839  break;
1840  case Comdat::Largest:
1841  case Comdat::SameSize:
1842  return false;
1843  }
1844  }
1845 
1846  if (G->hasSection()) {
1847  StringRef Section = G->getSection();
1848 
1849  // Globals from llvm.metadata aren't emitted, do not instrument them.
1850  if (Section == "llvm.metadata") return false;
1851  // Do not instrument globals from special LLVM sections.
1852  if (Section.find("__llvm") != StringRef::npos || Section.find("__LLVM") != StringRef::npos) return false;
1853 
1854  // Do not instrument function pointers to initialization and termination
1855  // routines: dynamic linker will not properly handle redzones.
1856  if (Section.startswith(".preinit_array") ||
1857  Section.startswith(".init_array") ||
1858  Section.startswith(".fini_array")) {
1859  return false;
1860  }
1861 
1862  // On COFF, if the section name contains '$', it is highly likely that the
1863  // user is using section sorting to create an array of globals similar to
1864  // the way initialization callbacks are registered in .init_array and
1865  // .CRT$XCU. The ATL also registers things in .ATL$__[azm]. Adding redzones
1866  // to such globals is counterproductive, because the intent is that they
1867  // will form an array, and out-of-bounds accesses are expected.
1868  // See https://github.com/google/sanitizers/issues/305
1869  // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
1870  if (TargetTriple.isOSBinFormatCOFF() && Section.contains('$')) {
1871  LLVM_DEBUG(dbgs() << "Ignoring global in sorted section (contains '$'): "
1872  << *G << "\n");
1873  return false;
1874  }
1875 
1876  if (TargetTriple.isOSBinFormatMachO()) {
1877  StringRef ParsedSegment, ParsedSection;
1878  unsigned TAA = 0, StubSize = 0;
1879  bool TAAParsed;
1880  std::string ErrorCode = MCSectionMachO::ParseSectionSpecifier(
1881  Section, ParsedSegment, ParsedSection, TAA, TAAParsed, StubSize);
1882  assert(ErrorCode.empty() && "Invalid section specifier.");
1883 
1884  // Ignore the globals from the __OBJC section. The ObjC runtime assumes
1885  // those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
1886  // them.
1887  if (ParsedSegment == "__OBJC" ||
1888  (ParsedSegment == "__DATA" && ParsedSection.startswith("__objc_"))) {
1889  LLVM_DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G << "\n");
1890  return false;
1891  }
1892  // See https://github.com/google/sanitizers/issues/32
1893  // Constant CFString instances are compiled in the following way:
1894  // -- the string buffer is emitted into
1895  // __TEXT,__cstring,cstring_literals
1896  // -- the constant NSConstantString structure referencing that buffer
1897  // is placed into __DATA,__cfstring
1898  // Therefore there's no point in placing redzones into __DATA,__cfstring.
1899  // Moreover, it causes the linker to crash on OS X 10.7
1900  if (ParsedSegment == "__DATA" && ParsedSection == "__cfstring") {
1901  LLVM_DEBUG(dbgs() << "Ignoring CFString: " << *G << "\n");
1902  return false;
1903  }
1904  // The linker merges the contents of cstring_literals and removes the
1905  // trailing zeroes.
1906  if (ParsedSegment == "__TEXT" && (TAA & MachO::S_CSTRING_LITERALS)) {
1907  LLVM_DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n");
1908  return false;
1909  }
1910  }
1911  }
1912 
1913  return true;
1914 }
1915 
1916 // On Mach-O platforms, we emit global metadata in a separate section of the
1917 // binary in order to allow the linker to properly dead strip. This is only
1918 // supported on recent versions of ld64.
1919 bool ModuleAddressSanitizer::ShouldUseMachOGlobalsSection() const {
1920  if (!TargetTriple.isOSBinFormatMachO())
1921  return false;
1922 
1923  if (TargetTriple.isMacOSX() && !TargetTriple.isMacOSXVersionLT(10, 11))
1924  return true;
1925  if (TargetTriple.isiOS() /* or tvOS */ && !TargetTriple.isOSVersionLT(9))
1926  return true;
1927  if (TargetTriple.isWatchOS() && !TargetTriple.isOSVersionLT(2))
1928  return true;
1929 
1930  return false;
1931 }
1932 
1933 StringRef ModuleAddressSanitizer::getGlobalMetadataSection() const {
1934  switch (TargetTriple.getObjectFormat()) {
1935  case Triple::COFF: return ".ASAN$GL";
1936  case Triple::ELF: return "asan_globals";
1937  case Triple::MachO: return "__DATA,__asan_globals,regular";
1938  case Triple::Wasm:
1939  case Triple::XCOFF:
1941  "ModuleAddressSanitizer not implemented for object file format.");
1943  break;
1944  }
1945  llvm_unreachable("unsupported object format");
1946 }
1947 
1948 void ModuleAddressSanitizer::initializeCallbacks(Module &M) {
1949  IRBuilder<> IRB(*C);
1950 
1951  // Declare our poisoning and unpoisoning functions.
1952  AsanPoisonGlobals =
1953  M.getOrInsertFunction(kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy);
1954  AsanUnpoisonGlobals =
1955  M.getOrInsertFunction(kAsanUnpoisonGlobalsName, IRB.getVoidTy());
1956 
1957  // Declare functions that register/unregister globals.
1958  AsanRegisterGlobals = M.getOrInsertFunction(
1959  kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
1960  AsanUnregisterGlobals = M.getOrInsertFunction(
1961  kAsanUnregisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
1962 
1963  // Declare the functions that find globals in a shared object and then invoke
1964  // the (un)register function on them.
1965  AsanRegisterImageGlobals = M.getOrInsertFunction(
1966  kAsanRegisterImageGlobalsName, IRB.getVoidTy(), IntptrTy);
1967  AsanUnregisterImageGlobals = M.getOrInsertFunction(
1968  kAsanUnregisterImageGlobalsName, IRB.getVoidTy(), IntptrTy);
1969 
1970  AsanRegisterElfGlobals =
1971  M.getOrInsertFunction(kAsanRegisterElfGlobalsName, IRB.getVoidTy(),
1972  IntptrTy, IntptrTy, IntptrTy);
1973  AsanUnregisterElfGlobals =
1974  M.getOrInsertFunction(kAsanUnregisterElfGlobalsName, IRB.getVoidTy(),
1975  IntptrTy, IntptrTy, IntptrTy);
1976 }
1977 
1978 // Put the metadata and the instrumented global in the same group. This ensures
1979 // that the metadata is discarded if the instrumented global is discarded.
1980 void ModuleAddressSanitizer::SetComdatForGlobalMetadata(
1981  GlobalVariable *G, GlobalVariable *Metadata, StringRef InternalSuffix) {
1982  Module &M = *G->getParent();
1983  Comdat *C = G->getComdat();
1984  if (!C) {
1985  if (!G->hasName()) {
1986  // If G is unnamed, it must be internal. Give it an artificial name
1987  // so we can put it in a comdat.
1988  assert(G->hasLocalLinkage());
1989  G->setName(Twine(kAsanGenPrefix) + "_anon_global");
1990  }
1991 
1992  if (!InternalSuffix.empty() && G->hasLocalLinkage()) {
1993  std::string Name = G->getName();
1994  Name += InternalSuffix;
1995  C = M.getOrInsertComdat(Name);
1996  } else {
1997  C = M.getOrInsertComdat(G->getName());
1998  }
1999 
2000  // Make this IMAGE_COMDAT_SELECT_NODUPLICATES on COFF. Also upgrade private
2001  // linkage to internal linkage so that a symbol table entry is emitted. This
2002  // is necessary in order to create the comdat group.
2003  if (TargetTriple.isOSBinFormatCOFF()) {
2005  if (G->hasPrivateLinkage())
2007  }
2008  G->setComdat(C);
2009  }
2010 
2011  assert(G->hasComdat());
2012  Metadata->setComdat(G->getComdat());
2013 }
2014 
2015 // Create a separate metadata global and put it in the appropriate ASan
2016 // global registration section.
2018 ModuleAddressSanitizer::CreateMetadataGlobal(Module &M, Constant *Initializer,
2019  StringRef OriginalName) {
2020  auto Linkage = TargetTriple.isOSBinFormatMachO()
2023  GlobalVariable *Metadata = new GlobalVariable(
2024  M, Initializer->getType(), false, Linkage, Initializer,
2025  Twine("__asan_global_") + GlobalValue::dropLLVMManglingEscape(OriginalName));
2026  Metadata->setSection(getGlobalMetadataSection());
2027  return Metadata;
2028 }
2029 
2030 IRBuilder<> ModuleAddressSanitizer::CreateAsanModuleDtor(Module &M) {
2031  AsanDtorFunction =
2033  GlobalValue::InternalLinkage, kAsanModuleDtorName, &M);
2034  BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
2035 
2036  return IRBuilder<>(ReturnInst::Create(*C, AsanDtorBB));
2037 }
2038 
2039 void ModuleAddressSanitizer::InstrumentGlobalsCOFF(
2040  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2041  ArrayRef<Constant *> MetadataInitializers) {
2042  assert(ExtendedGlobals.size() == MetadataInitializers.size());
2043  auto &DL = M.getDataLayout();
2044 
2045  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2046  Constant *Initializer = MetadataInitializers[i];
2047  GlobalVariable *G = ExtendedGlobals[i];
2048  GlobalVariable *Metadata =
2049  CreateMetadataGlobal(M, Initializer, G->getName());
2050 
2051  // The MSVC linker always inserts padding when linking incrementally. We
2052  // cope with that by aligning each struct to its size, which must be a power
2053  // of two.
2054  unsigned SizeOfGlobalStruct = DL.getTypeAllocSize(Initializer->getType());
2055  assert(isPowerOf2_32(SizeOfGlobalStruct) &&
2056  "global metadata will not be padded appropriately");
2057  Metadata->setAlignment(SizeOfGlobalStruct);
2058 
2059  SetComdatForGlobalMetadata(G, Metadata, "");
2060  }
2061 }
2062 
2063 void ModuleAddressSanitizer::InstrumentGlobalsELF(
2064  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2065  ArrayRef<Constant *> MetadataInitializers,
2066  const std::string &UniqueModuleId) {
2067  assert(ExtendedGlobals.size() == MetadataInitializers.size());
2068 
2069  SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
2070  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2071  GlobalVariable *G = ExtendedGlobals[i];
2072  GlobalVariable *Metadata =
2073  CreateMetadataGlobal(M, MetadataInitializers[i], G->getName());
2075  Metadata->setMetadata(LLVMContext::MD_associated, MD);
2076  MetadataGlobals[i] = Metadata;
2077 
2078  SetComdatForGlobalMetadata(G, Metadata, UniqueModuleId);
2079  }
2080 
2081  // Update llvm.compiler.used, adding the new metadata globals. This is
2082  // needed so that during LTO these variables stay alive.
2083  if (!MetadataGlobals.empty())
2084  appendToCompilerUsed(M, MetadataGlobals);
2085 
2086  // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2087  // to look up the loaded image that contains it. Second, we can store in it
2088  // whether registration has already occurred, to prevent duplicate
2089  // registration.
2090  //
2091  // Common linkage ensures that there is only one global per shared library.
2092  GlobalVariable *RegisteredFlag = new GlobalVariable(
2093  M, IntptrTy, false, GlobalVariable::CommonLinkage,
2094  ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
2096 
2097  // Create start and stop symbols.
2098  GlobalVariable *StartELFMetadata = new GlobalVariable(
2099  M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2100  "__start_" + getGlobalMetadataSection());
2102  GlobalVariable *StopELFMetadata = new GlobalVariable(
2103  M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2104  "__stop_" + getGlobalMetadataSection());
2106 
2107  // Create a call to register the globals with the runtime.
2108  IRB.CreateCall(AsanRegisterElfGlobals,
2109  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2110  IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2111  IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2112 
2113  // We also need to unregister globals at the end, e.g., when a shared library
2114  // gets closed.
2115  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2116  IRB_Dtor.CreateCall(AsanUnregisterElfGlobals,
2117  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2118  IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2119  IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2120 }
2121 
2122 void ModuleAddressSanitizer::InstrumentGlobalsMachO(
2123  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2124  ArrayRef<Constant *> MetadataInitializers) {
2125  assert(ExtendedGlobals.size() == MetadataInitializers.size());
2126 
2127  // On recent Mach-O platforms, use a structure which binds the liveness of
2128  // the global variable to the metadata struct. Keep the list of "Liveness" GV
2129  // created to be added to llvm.compiler.used
2130  StructType *LivenessTy = StructType::get(IntptrTy, IntptrTy);
2131  SmallVector<GlobalValue *, 16> LivenessGlobals(ExtendedGlobals.size());
2132 
2133  for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2134  Constant *Initializer = MetadataInitializers[i];
2135  GlobalVariable *G = ExtendedGlobals[i];
2136  GlobalVariable *Metadata =
2137  CreateMetadataGlobal(M, Initializer, G->getName());
2138 
2139  // On recent Mach-O platforms, we emit the global metadata in a way that
2140  // allows the linker to properly strip dead globals.
2141  auto LivenessBinder =
2142  ConstantStruct::get(LivenessTy, Initializer->getAggregateElement(0u),
2143  ConstantExpr::getPointerCast(Metadata, IntptrTy));
2144  GlobalVariable *Liveness = new GlobalVariable(
2145  M, LivenessTy, false, GlobalVariable::InternalLinkage, LivenessBinder,
2146  Twine("__asan_binder_") + G->getName());
2147  Liveness->setSection("__DATA,__asan_liveness,regular,live_support");
2148  LivenessGlobals[i] = Liveness;
2149  }
2150 
2151  // Update llvm.compiler.used, adding the new liveness globals. This is
2152  // needed so that during LTO these variables stay alive. The alternative
2153  // would be to have the linker handling the LTO symbols, but libLTO
2154  // current API does not expose access to the section for each symbol.
2155  if (!LivenessGlobals.empty())
2156  appendToCompilerUsed(M, LivenessGlobals);
2157 
2158  // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2159  // to look up the loaded image that contains it. Second, we can store in it
2160  // whether registration has already occurred, to prevent duplicate
2161  // registration.
2162  //
2163  // common linkage ensures that there is only one global per shared library.
2164  GlobalVariable *RegisteredFlag = new GlobalVariable(
2165  M, IntptrTy, false, GlobalVariable::CommonLinkage,
2166  ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
2168 
2169  IRB.CreateCall(AsanRegisterImageGlobals,
2170  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2171 
2172  // We also need to unregister globals at the end, e.g., when a shared library
2173  // gets closed.
2174  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2175  IRB_Dtor.CreateCall(AsanUnregisterImageGlobals,
2176  {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2177 }
2178 
2179 void ModuleAddressSanitizer::InstrumentGlobalsWithMetadataArray(
2180  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2181  ArrayRef<Constant *> MetadataInitializers) {
2182  assert(ExtendedGlobals.size() == MetadataInitializers.size());
2183  unsigned N = ExtendedGlobals.size();
2184  assert(N > 0);
2185 
2186  // On platforms that don't have a custom metadata section, we emit an array
2187  // of global metadata structures.
2188  ArrayType *ArrayOfGlobalStructTy =
2189  ArrayType::get(MetadataInitializers[0]->getType(), N);
2190  auto AllGlobals = new GlobalVariable(
2191  M, ArrayOfGlobalStructTy, false, GlobalVariable::InternalLinkage,
2192  ConstantArray::get(ArrayOfGlobalStructTy, MetadataInitializers), "");
2193  if (Mapping.Scale > 3)
2194  AllGlobals->setAlignment(1ULL << Mapping.Scale);
2195 
2196  IRB.CreateCall(AsanRegisterGlobals,
2197  {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2198  ConstantInt::get(IntptrTy, N)});
2199 
2200  // We also need to unregister globals at the end, e.g., when a shared library
2201  // gets closed.
2202  IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
2203  IRB_Dtor.CreateCall(AsanUnregisterGlobals,
2204  {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2205  ConstantInt::get(IntptrTy, N)});
2206 }
2207 
2208 // This function replaces all global variables with new variables that have
2209 // trailing redzones. It also creates a function that poisons
2210 // redzones and inserts this function into llvm.global_ctors.
2211 // Sets *CtorComdat to true if the global registration code emitted into the
2212 // asan constructor is comdat-compatible.
2213 bool ModuleAddressSanitizer::InstrumentGlobals(IRBuilder<> &IRB, Module &M,
2214  bool *CtorComdat) {
2215  *CtorComdat = false;
2216 
2217  SmallVector<GlobalVariable *, 16> GlobalsToChange;
2218 
2219  for (auto &G : M.globals()) {
2220  if (ShouldInstrumentGlobal(&G)) GlobalsToChange.push_back(&G);
2221  }
2222 
2223  size_t n = GlobalsToChange.size();
2224  if (n == 0) {
2225  *CtorComdat = true;
2226  return false;
2227  }
2228 
2229  auto &DL = M.getDataLayout();
2230 
2231  // A global is described by a structure
2232  // size_t beg;
2233  // size_t size;
2234  // size_t size_with_redzone;
2235  // const char *name;
2236  // const char *module_name;
2237  // size_t has_dynamic_init;
2238  // void *source_location;
2239  // size_t odr_indicator;
2240  // We initialize an array of such structures and pass it to a run-time call.
2241  StructType *GlobalStructTy =
2242  StructType::get(IntptrTy, IntptrTy, IntptrTy, IntptrTy, IntptrTy,
2243  IntptrTy, IntptrTy, IntptrTy);
2244  SmallVector<GlobalVariable *, 16> NewGlobals(n);
2245  SmallVector<Constant *, 16> Initializers(n);
2246 
2247  bool HasDynamicallyInitializedGlobals = false;
2248 
2249  // We shouldn't merge same module names, as this string serves as unique
2250  // module ID in runtime.
2252  M, M.getModuleIdentifier(), /*AllowMerging*/ false, kAsanGenPrefix);
2253 
2254  for (size_t i = 0; i < n; i++) {
2255  static const uint64_t kMaxGlobalRedzone = 1 << 18;
2256  GlobalVariable *G = GlobalsToChange[i];
2257 
2258  // FIXME: Metadata should be attched directly to the global directly instead
2259  // of being added to llvm.asan.globals.
2260  auto MD = GlobalsMD.get(G);
2261  StringRef NameForGlobal = G->getName();
2262  // Create string holding the global name (use global name from metadata
2263  // if it's available, otherwise just write the name of global variable).
2265  M, MD.Name.empty() ? NameForGlobal : MD.Name,
2266  /*AllowMerging*/ true, kAsanGenPrefix);
2267 
2268  Type *Ty = G->getValueType();
2269  uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
2270  uint64_t MinRZ = MinRedzoneSizeForGlobal();
2271  // MinRZ <= RZ <= kMaxGlobalRedzone
2272  // and trying to make RZ to be ~ 1/4 of SizeInBytes.
2273  uint64_t RZ = std::max(
2274  MinRZ, std::min(kMaxGlobalRedzone, (SizeInBytes / MinRZ / 4) * MinRZ));
2275  uint64_t RightRedzoneSize = RZ;
2276  // Round up to MinRZ
2277  if (SizeInBytes % MinRZ) RightRedzoneSize += MinRZ - (SizeInBytes % MinRZ);
2278  assert(((RightRedzoneSize + SizeInBytes) % MinRZ) == 0);
2279  Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
2280 
2281  StructType *NewTy = StructType::get(Ty, RightRedZoneTy);
2282  Constant *NewInitializer = ConstantStruct::get(
2283  NewTy, G->getInitializer(), Constant::getNullValue(RightRedZoneTy));
2284 
2285  // Create a new global variable with enough space for a redzone.
2286  GlobalValue::LinkageTypes Linkage = G->getLinkage();
2287  if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
2288  Linkage = GlobalValue::InternalLinkage;
2289  GlobalVariable *NewGlobal =
2290  new GlobalVariable(M, NewTy, G->isConstant(), Linkage, NewInitializer,
2291  "", G, G->getThreadLocalMode());
2292  NewGlobal->copyAttributesFrom(G);
2293  NewGlobal->setComdat(G->getComdat());
2294  NewGlobal->setAlignment(MinRZ);
2295  // Don't fold globals with redzones. ODR violation detector and redzone
2296  // poisoning implicitly creates a dependence on the global's address, so it
2297  // is no longer valid for it to be marked unnamed_addr.
2299 
2300  // Move null-terminated C strings to "__asan_cstring" section on Darwin.
2301  if (TargetTriple.isOSBinFormatMachO() && !G->hasSection() &&
2302  G->isConstant()) {
2303  auto Seq = dyn_cast<ConstantDataSequential>(G->getInitializer());
2304  if (Seq && Seq->isCString())
2305  NewGlobal->setSection("__TEXT,__asan_cstring,regular");
2306  }
2307 
2308  // Transfer the debug info. The payload starts at offset zero so we can
2309  // copy the debug info over as is.
2311  G->getDebugInfo(GVs);
2312  for (auto *GV : GVs)
2313  NewGlobal->addDebugInfo(GV);
2314 
2315  Value *Indices2[2];
2316  Indices2[0] = IRB.getInt32(0);
2317  Indices2[1] = IRB.getInt32(0);
2318 
2319  G->replaceAllUsesWith(
2320  ConstantExpr::getGetElementPtr(NewTy, NewGlobal, Indices2, true));
2321  NewGlobal->takeName(G);
2322  G->eraseFromParent();
2323  NewGlobals[i] = NewGlobal;
2324 
2325  Constant *SourceLoc;
2326  if (!MD.SourceLoc.empty()) {
2327  auto SourceLocGlobal = createPrivateGlobalForSourceLoc(M, MD.SourceLoc);
2328  SourceLoc = ConstantExpr::getPointerCast(SourceLocGlobal, IntptrTy);
2329  } else {
2330  SourceLoc = ConstantInt::get(IntptrTy, 0);
2331  }
2332 
2333  Constant *ODRIndicator = ConstantExpr::getNullValue(IRB.getInt8PtrTy());
2334  GlobalValue *InstrumentedGlobal = NewGlobal;
2335 
2336  bool CanUsePrivateAliases =
2337  TargetTriple.isOSBinFormatELF() || TargetTriple.isOSBinFormatMachO() ||
2338  TargetTriple.isOSBinFormatWasm();
2339  if (CanUsePrivateAliases && UsePrivateAlias) {
2340  // Create local alias for NewGlobal to avoid crash on ODR between
2341  // instrumented and non-instrumented libraries.
2342  InstrumentedGlobal =
2344  }
2345 
2346  // ODR should not happen for local linkage.
2347  if (NewGlobal->hasLocalLinkage()) {
2348  ODRIndicator = ConstantExpr::getIntToPtr(ConstantInt::get(IntptrTy, -1),
2349  IRB.getInt8PtrTy());
2350  } else if (UseOdrIndicator) {
2351  // With local aliases, we need to provide another externally visible
2352  // symbol __odr_asan_XXX to detect ODR violation.
2353  auto *ODRIndicatorSym =
2354  new GlobalVariable(M, IRB.getInt8Ty(), false, Linkage,
2356  kODRGenPrefix + NameForGlobal, nullptr,
2357  NewGlobal->getThreadLocalMode());
2358 
2359  // Set meaningful attributes for indicator symbol.
2360  ODRIndicatorSym->setVisibility(NewGlobal->getVisibility());
2361  ODRIndicatorSym->setDLLStorageClass(NewGlobal->getDLLStorageClass());
2362  ODRIndicatorSym->setAlignment(1);
2363  ODRIndicator = ODRIndicatorSym;
2364  }
2365 
2366  Constant *Initializer = ConstantStruct::get(
2367  GlobalStructTy,
2368  ConstantExpr::getPointerCast(InstrumentedGlobal, IntptrTy),
2369  ConstantInt::get(IntptrTy, SizeInBytes),
2370  ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
2371  ConstantExpr::getPointerCast(Name, IntptrTy),
2372  ConstantExpr::getPointerCast(ModuleName, IntptrTy),
2373  ConstantInt::get(IntptrTy, MD.IsDynInit), SourceLoc,
2374  ConstantExpr::getPointerCast(ODRIndicator, IntptrTy));
2375 
2376  if (ClInitializers && MD.IsDynInit) HasDynamicallyInitializedGlobals = true;
2377 
2378  LLVM_DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
2379 
2380  Initializers[i] = Initializer;
2381  }
2382 
2383  // Add instrumented globals to llvm.compiler.used list to avoid LTO from
2384  // ConstantMerge'ing them.
2385  SmallVector<GlobalValue *, 16> GlobalsToAddToUsedList;
2386  for (size_t i = 0; i < n; i++) {
2387  GlobalVariable *G = NewGlobals[i];
2388  if (G->getName().empty()) continue;
2389  GlobalsToAddToUsedList.push_back(G);
2390  }
2391  appendToCompilerUsed(M, ArrayRef<GlobalValue *>(GlobalsToAddToUsedList));
2392 
2393  std::string ELFUniqueModuleId =
2394  (UseGlobalsGC && TargetTriple.isOSBinFormatELF()) ? getUniqueModuleId(&M)
2395  : "";
2396 
2397  if (!ELFUniqueModuleId.empty()) {
2398  InstrumentGlobalsELF(IRB, M, NewGlobals, Initializers, ELFUniqueModuleId);
2399  *CtorComdat = true;
2400  } else if (UseGlobalsGC && TargetTriple.isOSBinFormatCOFF()) {
2401  InstrumentGlobalsCOFF(IRB, M, NewGlobals, Initializers);
2402  } else if (UseGlobalsGC && ShouldUseMachOGlobalsSection()) {
2403  InstrumentGlobalsMachO(IRB, M, NewGlobals, Initializers);
2404  } else {
2405  InstrumentGlobalsWithMetadataArray(IRB, M, NewGlobals, Initializers);
2406  }
2407 
2408  // Create calls for poisoning before initializers run and unpoisoning after.
2409  if (HasDynamicallyInitializedGlobals)
2410  createInitializerPoisonCalls(M, ModuleName);
2411 
2412  LLVM_DEBUG(dbgs() << M);
2413  return true;
2414 }
2415 
2416 int ModuleAddressSanitizer::GetAsanVersion(const Module &M) const {
2417  int LongSize = M.getDataLayout().getPointerSizeInBits();
2418  bool isAndroid = Triple(M.getTargetTriple()).isAndroid();
2419  int Version = 8;
2420  // 32-bit Android is one version ahead because of the switch to dynamic
2421  // shadow.
2422  Version += (LongSize == 32 && isAndroid);
2423  return Version;
2424 }
2425 
2426 bool ModuleAddressSanitizer::instrumentModule(Module &M) {
2427  initializeCallbacks(M);
2428 
2429  if (CompileKernel)
2430  return false;
2431 
2432  // Create a module constructor. A destructor is created lazily because not all
2433  // platforms, and not all modules need it.
2434  std::string AsanVersion = std::to_string(GetAsanVersion(M));
2435  std::string VersionCheckName =
2436  ClInsertVersionCheck ? (kAsanVersionCheckNamePrefix + AsanVersion) : "";
2437  std::tie(AsanCtorFunction, std::ignore) = createSanitizerCtorAndInitFunctions(
2438  M, kAsanModuleCtorName, kAsanInitName, /*InitArgTypes=*/{},
2439  /*InitArgs=*/{}, VersionCheckName);
2440 
2441  bool CtorComdat = true;
2442  bool Changed = false;
2443  // TODO(glider): temporarily disabled globals instrumentation for KASan.
2444  if (ClGlobals) {
2445  IRBuilder<> IRB(AsanCtorFunction->getEntryBlock().getTerminator());
2446  Changed |= InstrumentGlobals(IRB, M, &CtorComdat);
2447  }
2448 
2449  const uint64_t Priority = GetCtorAndDtorPriority(TargetTriple);
2450 
2451  // Put the constructor and destructor in comdat if both
2452  // (1) global instrumentation is not TU-specific
2453  // (2) target is ELF.
2454  if (UseCtorComdat && TargetTriple.isOSBinFormatELF() && CtorComdat) {
2455  AsanCtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleCtorName));
2456  appendToGlobalCtors(M, AsanCtorFunction, Priority, AsanCtorFunction);
2457  if (AsanDtorFunction) {
2458  AsanDtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleDtorName));
2459  appendToGlobalDtors(M, AsanDtorFunction, Priority, AsanDtorFunction);
2460  }
2461  } else {
2462  appendToGlobalCtors(M, AsanCtorFunction, Priority);
2463  if (AsanDtorFunction)
2464  appendToGlobalDtors(M, AsanDtorFunction, Priority);
2465  }
2466 
2467  return Changed;
2468 }
2469 
2470 void AddressSanitizer::initializeCallbacks(Module &M) {
2471  IRBuilder<> IRB(*C);
2472  // Create __asan_report* callbacks.
2473  // IsWrite, TypeSize and Exp are encoded in the function name.
2474  for (int Exp = 0; Exp < 2; Exp++) {
2475  for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
2476  const std::string TypeStr = AccessIsWrite ? "store" : "load";
2477  const std::string ExpStr = Exp ? "exp_" : "";
2478  const std::string EndingStr = Recover ? "_noabort" : "";
2479 
2480  SmallVector<Type *, 3> Args2 = {IntptrTy, IntptrTy};
2481  SmallVector<Type *, 2> Args1{1, IntptrTy};
2482  if (Exp) {
2483  Type *ExpType = Type::getInt32Ty(*C);
2484  Args2.push_back(ExpType);
2485  Args1.push_back(ExpType);
2486  }
2487  AsanErrorCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
2488  kAsanReportErrorTemplate + ExpStr + TypeStr + "_n" + EndingStr,
2489  FunctionType::get(IRB.getVoidTy(), Args2, false));
2490 
2491  AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
2492  ClMemoryAccessCallbackPrefix + ExpStr + TypeStr + "N" + EndingStr,
2493  FunctionType::get(IRB.getVoidTy(), Args2, false));
2494 
2495  for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
2496  AccessSizeIndex++) {
2497  const std::string Suffix = TypeStr + itostr(1ULL << AccessSizeIndex);
2498  AsanErrorCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2500  kAsanReportErrorTemplate + ExpStr + Suffix + EndingStr,
2501  FunctionType::get(IRB.getVoidTy(), Args1, false));
2502 
2503  AsanMemoryAccessCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2505  ClMemoryAccessCallbackPrefix + ExpStr + Suffix + EndingStr,
2506  FunctionType::get(IRB.getVoidTy(), Args1, false));
2507  }
2508  }
2509  }
2510 
2511  const std::string MemIntrinCallbackPrefix =
2512  CompileKernel ? std::string("") : ClMemoryAccessCallbackPrefix;
2513  AsanMemmove = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memmove",
2514  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2515  IRB.getInt8PtrTy(), IntptrTy);
2516  AsanMemcpy = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memcpy",
2517  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2518  IRB.getInt8PtrTy(), IntptrTy);
2519  AsanMemset = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memset",
2520  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2521  IRB.getInt32Ty(), IntptrTy);
2522 
2523  AsanHandleNoReturnFunc =
2524  M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy());
2525 
2526  AsanPtrCmpFunction =
2527  M.getOrInsertFunction(kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy);
2528  AsanPtrSubFunction =
2529  M.getOrInsertFunction(kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy);
2530  // We insert an empty inline asm after __asan_report* to avoid callback merge.
2531  EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
2532  StringRef(""), StringRef(""),
2533  /*hasSideEffects=*/true);
2534  if (Mapping.InGlobal)
2535  AsanShadowGlobal = M.getOrInsertGlobal("__asan_shadow",
2536  ArrayType::get(IRB.getInt8Ty(), 0));
2537 }
2538 
2539 bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
2540  // For each NSObject descendant having a +load method, this method is invoked
2541  // by the ObjC runtime before any of the static constructors is called.
2542  // Therefore we need to instrument such methods with a call to __asan_init
2543  // at the beginning in order to initialize our runtime before any access to
2544  // the shadow memory.
2545  // We cannot just ignore these methods, because they may call other
2546  // instrumented functions.
2547  if (F.getName().find(" load]") != std::string::npos) {
2548  FunctionCallee AsanInitFunction =
2550  IRBuilder<> IRB(&F.front(), F.front().begin());
2551  IRB.CreateCall(AsanInitFunction, {});
2552  return true;
2553  }
2554  return false;
2555 }
2556 
2557 void AddressSanitizer::maybeInsertDynamicShadowAtFunctionEntry(Function &F) {
2558  // Generate code only when dynamic addressing is needed.
2559  if (Mapping.Offset != kDynamicShadowSentinel)
2560  return;
2561 
2562  IRBuilder<> IRB(&F.front().front());
2563  if (Mapping.InGlobal) {
2565  // An empty inline asm with input reg == output reg.
2566  // An opaque pointer-to-int cast, basically.
2568  FunctionType::get(IntptrTy, {AsanShadowGlobal->getType()}, false),
2569  StringRef(""), StringRef("=r,0"),
2570  /*hasSideEffects=*/false);
2571  LocalDynamicShadow =
2572  IRB.CreateCall(Asm, {AsanShadowGlobal}, ".asan.shadow");
2573  } else {
2574  LocalDynamicShadow =
2575  IRB.CreatePointerCast(AsanShadowGlobal, IntptrTy, ".asan.shadow");
2576  }
2577  } else {
2578  Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
2579  kAsanShadowMemoryDynamicAddress, IntptrTy);
2580  LocalDynamicShadow = IRB.CreateLoad(IntptrTy, GlobalDynamicAddress);
2581  }
2582 }
2583 
2584 void AddressSanitizer::markEscapedLocalAllocas(Function &F) {
2585  // Find the one possible call to llvm.localescape and pre-mark allocas passed
2586  // to it as uninteresting. This assumes we haven't started processing allocas
2587  // yet. This check is done up front because iterating the use list in
2588  // isInterestingAlloca would be algorithmically slower.
2589  assert(ProcessedAllocas.empty() && "must process localescape before allocas");
2590 
2591  // Try to get the declaration of llvm.localescape. If it's not in the module,
2592  // we can exit early.
2593  if (!F.getParent()->getFunction("llvm.localescape")) return;
2594 
2595  // Look for a call to llvm.localescape call in the entry block. It can't be in
2596  // any other block.
2597  for (Instruction &I : F.getEntryBlock()) {
2599  if (II && II->getIntrinsicID() == Intrinsic::localescape) {
2600  // We found a call. Mark all the allocas passed in as uninteresting.
2601  for (Value *Arg : II->arg_operands()) {
2602  AllocaInst *AI = dyn_cast<AllocaInst>(Arg->stripPointerCasts());
2603  assert(AI && AI->isStaticAlloca() &&
2604  "non-static alloca arg to localescape");
2605  ProcessedAllocas[AI] = false;
2606  }
2607  break;
2608  }
2609  }
2610 }
2611 
2612 bool AddressSanitizer::instrumentFunction(Function &F,
2613  const TargetLibraryInfo *TLI) {
2614  if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
2615  if (!ClDebugFunc.empty() && ClDebugFunc == F.getName()) return false;
2616  if (F.getName().startswith("__asan_")) return false;
2617 
2618  bool FunctionModified = false;
2619 
2620  // If needed, insert __asan_init before checking for SanitizeAddress attr.
2621  // This function needs to be called even if the function body is not
2622  // instrumented.
2623  if (maybeInsertAsanInitAtFunctionEntry(F))
2624  FunctionModified = true;
2625 
2626  // Leave if the function doesn't need instrumentation.
2627  if (!F.hasFnAttribute(Attribute::SanitizeAddress)) return FunctionModified;
2628 
2629  LLVM_DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
2630 
2631  initializeCallbacks(*F.getParent());
2632 
2633  FunctionStateRAII CleanupObj(this);
2634 
2635  maybeInsertDynamicShadowAtFunctionEntry(F);
2636 
2637  // We can't instrument allocas used with llvm.localescape. Only static allocas
2638  // can be passed to that intrinsic.
2639  markEscapedLocalAllocas(F);
2640 
2641  // We want to instrument every address only once per basic block (unless there
2642  // are calls between uses).
2643  SmallPtrSet<Value *, 16> TempsToInstrument;
2644  SmallVector<Instruction *, 16> ToInstrument;
2645  SmallVector<Instruction *, 8> NoReturnCalls;
2647  SmallVector<Instruction *, 16> PointerComparisonsOrSubtracts;
2648  int NumAllocas = 0;
2649  bool IsWrite;
2650  unsigned Alignment;
2651  uint64_t TypeSize;
2652 
2653  // Fill the set of memory operations to instrument.
2654  for (auto &BB : F) {
2655  AllBlocks.push_back(&BB);
2656  TempsToInstrument.clear();
2657  int NumInsnsPerBB = 0;
2658  for (auto &Inst : BB) {
2659  if (LooksLikeCodeInBug11395(&Inst)) return false;
2660  Value *MaybeMask = nullptr;
2661  if (Value *Addr = isInterestingMemoryAccess(&Inst, &IsWrite, &TypeSize,
2662  &Alignment, &MaybeMask)) {
2663  if (ClOpt && ClOptSameTemp) {
2664  // If we have a mask, skip instrumentation if we've already
2665  // instrumented the full object. But don't add to TempsToInstrument
2666  // because we might get another load/store with a different mask.
2667  if (MaybeMask) {
2668  if (TempsToInstrument.count(Addr))
2669  continue; // We've seen this (whole) temp in the current BB.
2670  } else {
2671  if (!TempsToInstrument.insert(Addr).second)
2672  continue; // We've seen this temp in the current BB.
2673  }
2674  }
2675  } else if (((ClInvalidPointerPairs || ClInvalidPointerCmp) &&
2679  PointerComparisonsOrSubtracts.push_back(&Inst);
2680  continue;
2681  } else if (isa<MemIntrinsic>(Inst)) {
2682  // ok, take it.
2683  } else {
2684  if (isa<AllocaInst>(Inst)) NumAllocas++;
2685  CallSite CS(&Inst);
2686  if (CS) {
2687  // A call inside BB.
2688  TempsToInstrument.clear();
2689  if (CS.doesNotReturn() && !CS->hasMetadata("nosanitize"))
2690  NoReturnCalls.push_back(CS.getInstruction());
2691  }
2692  if (CallInst *CI = dyn_cast<CallInst>(&Inst))
2694  continue;
2695  }
2696  ToInstrument.push_back(&Inst);
2697  NumInsnsPerBB++;
2698  if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB) break;
2699  }
2700  }
2701 
2702  bool UseCalls =
2705  const DataLayout &DL = F.getParent()->getDataLayout();
2706  ObjectSizeOpts ObjSizeOpts;
2707  ObjSizeOpts.RoundToAlign = true;
2708  ObjectSizeOffsetVisitor ObjSizeVis(DL, TLI, F.getContext(), ObjSizeOpts);
2709 
2710  // Instrument.
2711  int NumInstrumented = 0;
2712  for (auto Inst : ToInstrument) {
2713  if (ClDebugMin < 0 || ClDebugMax < 0 ||
2714  (NumInstrumented >= ClDebugMin && NumInstrumented <= ClDebugMax)) {
2715  if (isInterestingMemoryAccess(Inst, &IsWrite, &TypeSize, &Alignment))
2716  instrumentMop(ObjSizeVis, Inst, UseCalls,
2717  F.getParent()->getDataLayout());
2718  else
2719  instrumentMemIntrinsic(cast<MemIntrinsic>(Inst));
2720  }
2721  NumInstrumented++;
2722  }
2723 
2724  FunctionStackPoisoner FSP(F, *this);
2725  bool ChangedStack = FSP.runOnFunction();
2726 
2727  // We must unpoison the stack before NoReturn calls (throw, _exit, etc).
2728  // See e.g. https://github.com/google/sanitizers/issues/37
2729  for (auto CI : NoReturnCalls) {
2730  IRBuilder<> IRB(CI);
2731  IRB.CreateCall(AsanHandleNoReturnFunc, {});
2732  }
2733 
2734  for (auto Inst : PointerComparisonsOrSubtracts) {
2735  instrumentPointerComparisonOrSubtraction(Inst);
2736  NumInstrumented++;
2737  }
2738 
2739  if (NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty())
2740  FunctionModified = true;
2741 
2742  LLVM_DEBUG(dbgs() << "ASAN done instrumenting: " << FunctionModified << " "
2743  << F << "\n");
2744 
2745  return FunctionModified;
2746 }
2747 
2748 // Workaround for bug 11395: we don't want to instrument stack in functions
2749 // with large assembly blobs (32-bit only), otherwise reg alloc may crash.
2750 // FIXME: remove once the bug 11395 is fixed.
2751 bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
2752  if (LongSize != 32) return false;
2753  CallInst *CI = dyn_cast<CallInst>(I);
2754  if (!CI || !CI->isInlineAsm()) return false;
2755  if (CI->getNumArgOperands() <= 5) return false;
2756  // We have inline assembly with quite a few arguments.
2757  return true;
2758 }
2759 
2760 void FunctionStackPoisoner::initializeCallbacks(Module &M) {
2761  IRBuilder<> IRB(*C);
2762  for (int i = 0; i <= kMaxAsanStackMallocSizeClass; i++) {
2763  std::string Suffix = itostr(i);
2764  AsanStackMallocFunc[i] = M.getOrInsertFunction(
2765  kAsanStackMallocNameTemplate + Suffix, IntptrTy, IntptrTy);
2766  AsanStackFreeFunc[i] =
2767  M.getOrInsertFunction(kAsanStackFreeNameTemplate + Suffix,
2768  IRB.getVoidTy(), IntptrTy, IntptrTy);
2769  }
2770  if (ASan.UseAfterScope) {
2771  AsanPoisonStackMemoryFunc = M.getOrInsertFunction(
2772  kAsanPoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2773  AsanUnpoisonStackMemoryFunc = M.getOrInsertFunction(
2774  kAsanUnpoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2775  }
2776 
2777  for (size_t Val : {0x00, 0xf1, 0xf2, 0xf3, 0xf5, 0xf8}) {
2778  std::ostringstream Name;
2779  Name << kAsanSetShadowPrefix;
2780  Name << std::setw(2) << std::setfill('0') << std::hex << Val;
2781  AsanSetShadowFunc[Val] =
2782  M.getOrInsertFunction(Name.str(), IRB.getVoidTy(), IntptrTy, IntptrTy);
2783  }
2784 
2785  AsanAllocaPoisonFunc = M.getOrInsertFunction(
2786  kAsanAllocaPoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
2787  AsanAllocasUnpoisonFunc = M.getOrInsertFunction(
2788  kAsanAllocasUnpoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
2789 }
2790 
2791 void FunctionStackPoisoner::copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
2792  ArrayRef<uint8_t> ShadowBytes,
2793  size_t Begin, size_t End,
2794  IRBuilder<> &IRB,
2795  Value *ShadowBase) {
2796  if (Begin >= End)
2797  return;
2798 
2799  const size_t LargestStoreSizeInBytes =
2800  std::min<size_t>(sizeof(uint64_t), ASan.LongSize / 8);
2801 
2802  const bool IsLittleEndian = F.getParent()->getDataLayout().isLittleEndian();
2803 
2804  // Poison given range in shadow using larges store size with out leading and
2805  // trailing zeros in ShadowMask. Zeros never change, so they need neither
2806  // poisoning nor up-poisoning. Still we don't mind if some of them get into a
2807  // middle of a store.
2808  for (size_t i = Begin; i < End;) {
2809  if (!ShadowMask[i]) {
2810  assert(!ShadowBytes[i]);
2811  ++i;
2812  continue;
2813  }
2814 
2815  size_t StoreSizeInBytes = LargestStoreSizeInBytes;
2816  // Fit store size into the range.
2817  while (StoreSizeInBytes > End - i)
2818  StoreSizeInBytes /= 2;
2819 
2820  // Minimize store size by trimming trailing zeros.
2821  for (size_t j = StoreSizeInBytes - 1; j && !ShadowMask[i + j]; --j) {
2822  while (j <= StoreSizeInBytes / 2)
2823  StoreSizeInBytes /= 2;
2824  }
2825 
2826  uint64_t Val = 0;
2827  for (size_t j = 0; j < StoreSizeInBytes; j++) {
2828  if (IsLittleEndian)
2829  Val |= (uint64_t)ShadowBytes[i + j] << (8 * j);
2830  else
2831  Val = (Val << 8) | ShadowBytes[i + j];
2832  }
2833 
2834  Value *Ptr = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
2835  Value *Poison = IRB.getIntN(StoreSizeInBytes * 8, Val);
2836  IRB.CreateAlignedStore(
2837  Poison, IRB.CreateIntToPtr(Ptr, Poison->getType()->getPointerTo()), 1);
2838 
2839  i += StoreSizeInBytes;
2840  }
2841 }
2842 
2843 void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2844  ArrayRef<uint8_t> ShadowBytes,
2845  IRBuilder<> &IRB, Value *ShadowBase) {
2846  copyToShadow(ShadowMask, ShadowBytes, 0, ShadowMask.size(), IRB, ShadowBase);
2847 }
2848 
2849 void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2850  ArrayRef<uint8_t> ShadowBytes,
2851  size_t Begin, size_t End,
2852  IRBuilder<> &IRB, Value *ShadowBase) {
2853  assert(ShadowMask.size() == ShadowBytes.size());
2854  size_t Done = Begin;
2855  for (size_t i = Begin, j = Begin + 1; i < End; i = j++) {
2856  if (!ShadowMask[i]) {
2857  assert(!ShadowBytes[i]);
2858  continue;
2859  }
2860  uint8_t Val = ShadowBytes[i];
2861  if (!AsanSetShadowFunc[Val])
2862  continue;
2863 
2864  // Skip same values.
2865  for (; j < End && ShadowMask[j] && Val == ShadowBytes[j]; ++j) {
2866  }
2867 
2868  if (j - i >= ClMaxInlinePoisoningSize) {
2869  copyToShadowInline(ShadowMask, ShadowBytes, Done, i, IRB, ShadowBase);
2870  IRB.CreateCall(AsanSetShadowFunc[Val],
2871  {IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i)),
2872  ConstantInt::get(IntptrTy, j - i)});
2873  Done = j;
2874  }
2875  }
2876 
2877  copyToShadowInline(ShadowMask, ShadowBytes, Done, End, IRB, ShadowBase);
2878 }
2879 
2880 // Fake stack allocator (asan_fake_stack.h) has 11 size classes
2881 // for every power of 2 from kMinStackMallocSize to kMaxAsanStackMallocSizeClass
2882 static int StackMallocSizeClass(uint64_t LocalStackSize) {
2883  assert(LocalStackSize <= kMaxStackMallocSize);
2884  uint64_t MaxSize = kMinStackMallocSize;
2885  for (int i = 0;; i++, MaxSize *= 2)
2886  if (LocalStackSize <= MaxSize) return i;
2887  llvm_unreachable("impossible LocalStackSize");
2888 }
2889 
2890 void FunctionStackPoisoner::copyArgsPassedByValToAllocas() {
2891  Instruction *CopyInsertPoint = &F.front().front();
2892  if (CopyInsertPoint == ASan.LocalDynamicShadow) {
2893  // Insert after the dynamic shadow location is determined
2894  CopyInsertPoint = CopyInsertPoint->getNextNode();
2895  assert(CopyInsertPoint);
2896  }
2897  IRBuilder<> IRB(CopyInsertPoint);
2898  const DataLayout &DL = F.getParent()->getDataLayout();
2899  for (Argument &Arg : F.args()) {
2900  if (Arg.hasByValAttr()) {
2901  Type *Ty = Arg.getType()->getPointerElementType();
2902  unsigned Align = Arg.getParamAlignment();
2903  if (Align == 0) Align = DL.getABITypeAlignment(Ty);
2904 
2905  AllocaInst *AI = IRB.CreateAlloca(
2906  Ty, nullptr,
2907  (Arg.hasName() ? Arg.getName() : "Arg" + Twine(Arg.getArgNo())) +
2908  ".byval");
2909  AI->setAlignment(Align);
2910  Arg.replaceAllUsesWith(AI);
2911 
2912  uint64_t AllocSize = DL.getTypeAllocSize(Ty);
2913  IRB.CreateMemCpy(AI, Align, &Arg, Align, AllocSize);
2914  }
2915  }
2916 }
2917 
2918 PHINode *FunctionStackPoisoner::createPHI(IRBuilder<> &IRB, Value *Cond,
2919  Value *ValueIfTrue,
2920  Instruction *ThenTerm,
2921  Value *ValueIfFalse) {
2922  PHINode *PHI = IRB.CreatePHI(IntptrTy, 2);
2923  BasicBlock *CondBlock = cast<Instruction>(Cond)->getParent();
2924  PHI->addIncoming(ValueIfFalse, CondBlock);
2925  BasicBlock *ThenBlock = ThenTerm->getParent();
2926  PHI->addIncoming(ValueIfTrue, ThenBlock);
2927  return PHI;
2928 }
2929 
2930 Value *FunctionStackPoisoner::createAllocaForLayout(
2931  IRBuilder<> &IRB, const ASanStackFrameLayout &L, bool Dynamic) {
2932  AllocaInst *Alloca;
2933  if (Dynamic) {
2934  Alloca = IRB.CreateAlloca(IRB.getInt8Ty(),
2936  "MyAlloca");
2937  } else {
2938  Alloca = IRB.CreateAlloca(ArrayType::get(IRB.getInt8Ty(), L.FrameSize),
2939  nullptr, "MyAlloca");
2940  assert(Alloca->isStaticAlloca());
2941  }
2942  assert((ClRealignStack & (ClRealignStack - 1)) == 0);
2943  size_t FrameAlignment = std::max(L.FrameAlignment, (size_t)ClRealignStack);
2944  Alloca->setAlignment(FrameAlignment);
2945  return IRB.CreatePointerCast(Alloca, IntptrTy);
2946 }
2947 
2948 void FunctionStackPoisoner::createDynamicAllocasInitStorage() {
2949  BasicBlock &FirstBB = *F.begin();
2950  IRBuilder<> IRB(dyn_cast<Instruction>(FirstBB.begin()));
2951  DynamicAllocaLayout = IRB.CreateAlloca(IntptrTy, nullptr);
2952  IRB.CreateStore(Constant::getNullValue(IntptrTy), DynamicAllocaLayout);
2953  DynamicAllocaLayout->setAlignment(32);
2954 }
2955 
2956 void FunctionStackPoisoner::processDynamicAllocas() {
2957  if (!ClInstrumentDynamicAllocas || DynamicAllocaVec.empty()) {
2958  assert(DynamicAllocaPoisonCallVec.empty());
2959  return;
2960  }
2961 
2962  // Insert poison calls for lifetime intrinsics for dynamic allocas.
2963  for (const auto &APC : DynamicAllocaPoisonCallVec) {
2964  assert(APC.InsBefore);
2965  assert(APC.AI);
2966  assert(ASan.isInterestingAlloca(*APC.AI));
2967  assert(!APC.AI->isStaticAlloca());
2968 
2969  IRBuilder<> IRB(APC.InsBefore);
2970  poisonAlloca(APC.AI, APC.Size, IRB, APC.DoPoison);
2971  // Dynamic allocas will be unpoisoned unconditionally below in
2972  // unpoisonDynamicAllocas.
2973  // Flag that we need unpoison static allocas.
2974  }
2975 
2976  // Handle dynamic allocas.
2977  createDynamicAllocasInitStorage();
2978  for (auto &AI : DynamicAllocaVec)
2979  handleDynamicAllocaCall(AI);
2980  unpoisonDynamicAllocas();
2981 }
2982 
2983 void FunctionStackPoisoner::processStaticAllocas() {
2984  if (AllocaVec.empty()) {
2985  assert(StaticAllocaPoisonCallVec.empty());
2986  return;
2987  }
2988 
2989  int StackMallocIdx = -1;
2990  DebugLoc EntryDebugLocation;
2991  if (auto SP = F.getSubprogram())
2992  EntryDebugLocation = DebugLoc::get(SP->getScopeLine(), 0, SP);
2993 
2994  Instruction *InsBefore = AllocaVec[0];
2995  IRBuilder<> IRB(InsBefore);
2996  IRB.SetCurrentDebugLocation(EntryDebugLocation);
2997 
2998  // Make sure non-instrumented allocas stay in the entry block. Otherwise,
2999  // debug info is broken, because only entry-block allocas are treated as
3000  // regular stack slots.
3001  auto InsBeforeB = InsBefore->getParent();
3002  assert(InsBeforeB == &F.getEntryBlock());
3003  for (auto *AI : StaticAllocasToMoveUp)
3004  if (AI->getParent() == InsBeforeB)
3005  AI->moveBefore(InsBefore);
3006 
3007  // If we have a call to llvm.localescape, keep it in the entry block.
3008  if (LocalEscapeCall) LocalEscapeCall->moveBefore(InsBefore);
3009 
3011  SVD.reserve(AllocaVec.size());
3012  for (AllocaInst *AI : AllocaVec) {
3014  ASan.getAllocaSizeInBytes(*AI),
3015  0,
3016  AI->getAlignment(),
3017  AI,
3018  0,
3019  0};
3020  SVD.push_back(D);
3021  }
3022 
3023  // Minimal header size (left redzone) is 4 pointers,
3024  // i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms.
3025  size_t Granularity = 1ULL << Mapping.Scale;
3026  size_t MinHeaderSize = std::max((size_t)ASan.LongSize / 2, Granularity);
3027  const ASanStackFrameLayout &L =
3028  ComputeASanStackFrameLayout(SVD, Granularity, MinHeaderSize);
3029 
3030  // Build AllocaToSVDMap for ASanStackVariableDescription lookup.
3032  for (auto &Desc : SVD)
3033  AllocaToSVDMap[Desc.AI] = &Desc;
3034 
3035  // Update SVD with information from lifetime intrinsics.
3036  for (const auto &APC : StaticAllocaPoisonCallVec) {
3037  assert(APC.InsBefore);
3038  assert(APC.AI);
3039  assert(ASan.isInterestingAlloca(*APC.AI));
3040  assert(APC.AI->isStaticAlloca());
3041 
3042  ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3043  Desc.LifetimeSize = Desc.Size;
3044  if (const DILocation *FnLoc = EntryDebugLocation.get()) {
3045  if (const DILocation *LifetimeLoc = APC.InsBefore->getDebugLoc().get()) {
3046  if (LifetimeLoc->getFile() == FnLoc->getFile())
3047  if (unsigned Line = LifetimeLoc->getLine())
3048  Desc.Line = std::min(Desc.Line ? Desc.Line : Line, Line);
3049  }
3050  }
3051  }
3052 
3053  auto DescriptionString = ComputeASanStackFrameDescription(SVD);
3054  LLVM_DEBUG(dbgs() << DescriptionString << " --- " << L.FrameSize << "\n");
3055  uint64_t LocalStackSize = L.FrameSize;
3056  bool DoStackMalloc = ClUseAfterReturn && !ASan.CompileKernel &&
3057  LocalStackSize <= kMaxStackMallocSize;
3058  bool DoDynamicAlloca = ClDynamicAllocaStack;
3059  // Don't do dynamic alloca or stack malloc if:
3060  // 1) There is inline asm: too often it makes assumptions on which registers
3061  // are available.
3062  // 2) There is a returns_twice call (typically setjmp), which is
3063  // optimization-hostile, and doesn't play well with introduced indirect
3064  // register-relative calculation of local variable addresses.
3065  DoDynamicAlloca &= !HasNonEmptyInlineAsm && !HasReturnsTwiceCall;
3066  DoStackMalloc &= !HasNonEmptyInlineAsm && !HasReturnsTwiceCall;
3067 
3068  Value *StaticAlloca =
3069  DoDynamicAlloca ? nullptr : createAllocaForLayout(IRB, L, false);
3070 
3071  Value *FakeStack;
3072  Value *LocalStackBase;
3073  Value *LocalStackBaseAlloca;
3074  uint8_t DIExprFlags = DIExpression::ApplyOffset;
3075 
3076  if (DoStackMalloc) {
3077  LocalStackBaseAlloca =
3078  IRB.CreateAlloca(IntptrTy, nullptr, "asan_local_stack_base");
3079  // void *FakeStack = __asan_option_detect_stack_use_after_return
3080  // ? __asan_stack_malloc_N(LocalStackSize)
3081  // : nullptr;
3082  // void *LocalStackBase = (FakeStack) ? FakeStack : alloca(LocalStackSize);
3083  Constant *OptionDetectUseAfterReturn = F.getParent()->getOrInsertGlobal(
3084  kAsanOptionDetectUseAfterReturn, IRB.getInt32Ty());
3085  Value *UseAfterReturnIsEnabled = IRB.CreateICmpNE(
3086  IRB.CreateLoad(IRB.getInt32Ty(), OptionDetectUseAfterReturn),
3088  Instruction *Term =
3089  SplitBlockAndInsertIfThen(UseAfterReturnIsEnabled, InsBefore, false);
3090  IRBuilder<> IRBIf(Term);
3091  IRBIf.SetCurrentDebugLocation(EntryDebugLocation);
3092  StackMallocIdx = StackMallocSizeClass(LocalStackSize);
3093  assert(StackMallocIdx <= kMaxAsanStackMallocSizeClass);
3094  Value *FakeStackValue =
3095  IRBIf.CreateCall(AsanStackMallocFunc[StackMallocIdx],
3096  ConstantInt::get(IntptrTy, LocalStackSize));
3097  IRB.SetInsertPoint(InsBefore);
3098  IRB.SetCurrentDebugLocation(EntryDebugLocation);
3099  FakeStack = createPHI(IRB, UseAfterReturnIsEnabled, FakeStackValue, Term,
3100  ConstantInt::get(IntptrTy, 0));
3101 
3102  Value *NoFakeStack =
3103  IRB.CreateICmpEQ(FakeStack, Constant::getNullValue(IntptrTy));
3104  Term = SplitBlockAndInsertIfThen(NoFakeStack, InsBefore, false);
3105  IRBIf.SetInsertPoint(Term);
3106  IRBIf.SetCurrentDebugLocation(EntryDebugLocation);
3107  Value *AllocaValue =
3108  DoDynamicAlloca ? createAllocaForLayout(IRBIf, L, true) : StaticAlloca;
3109 
3110  IRB.SetInsertPoint(InsBefore);
3111  IRB.SetCurrentDebugLocation(EntryDebugLocation);
3112  LocalStackBase = createPHI(IRB, NoFakeStack, AllocaValue, Term, FakeStack);
3113  IRB.SetCurrentDebugLocation(EntryDebugLocation);
3114  IRB.CreateStore(LocalStackBase, LocalStackBaseAlloca);
3115  DIExprFlags |= DIExpression::DerefBefore;
3116  } else {
3117  // void *FakeStack = nullptr;
3118  // void *LocalStackBase = alloca(LocalStackSize);
3119  FakeStack = ConstantInt::get(IntptrTy, 0);
3120  LocalStackBase =
3121  DoDynamicAlloca ? createAllocaForLayout(IRB, L, true) : StaticAlloca;
3122  LocalStackBaseAlloca = LocalStackBase;
3123  }
3124 
3125  // Replace Alloca instructions with base+offset.
3126  for (const auto &Desc : SVD) {
3127  AllocaInst *AI = Desc.AI;
3128  replaceDbgDeclareForAlloca(AI, LocalStackBaseAlloca, DIB, DIExprFlags,
3129  Desc.Offset);
3130  Value *NewAllocaPtr = IRB.CreateIntToPtr(
3131  IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Desc.Offset)),
3132  AI->getType());
3133  AI->replaceAllUsesWith(NewAllocaPtr);
3134  }
3135 
3136  // The left-most redzone has enough space for at least 4 pointers.
3137  // Write the Magic value to redzone[0].
3138  Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
3140  BasePlus0);
3141  // Write the frame description constant to redzone[1].
3142  Value *BasePlus1 = IRB.CreateIntToPtr(
3143  IRB.CreateAdd(LocalStackBase,
3144  ConstantInt::get(IntptrTy, ASan.LongSize / 8)),
3145  IntptrPtrTy);
3146  GlobalVariable *StackDescriptionGlobal =
3147  createPrivateGlobalForString(*F.getParent(), DescriptionString,
3148  /*AllowMerging*/ true, kAsanGenPrefix);
3149  Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal, IntptrTy);
3150  IRB.CreateStore(Description, BasePlus1);
3151  // Write the PC to redzone[2].
3152  Value *BasePlus2 = IRB.CreateIntToPtr(
3153  IRB.CreateAdd(LocalStackBase,
3154  ConstantInt::get(IntptrTy, 2 * ASan.LongSize / 8)),
3155  IntptrPtrTy);
3156  IRB.CreateStore(IRB.CreatePointerCast(&F, IntptrTy), BasePlus2);
3157 
3158  const auto &ShadowAfterScope = GetShadowBytesAfterScope(SVD, L);
3159 
3160  // Poison the stack red zones at the entry.
3161  Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
3162  // As mask we must use most poisoned case: red zones and after scope.
3163  // As bytes we can use either the same or just red zones only.
3164  copyToShadow(ShadowAfterScope, ShadowAfterScope, IRB, ShadowBase);
3165 
3166  if (!StaticAllocaPoisonCallVec.empty()) {
3167  const auto &ShadowInScope = GetShadowBytes(SVD, L);
3168 
3169  // Poison static allocas near lifetime intrinsics.
3170  for (const auto &APC : StaticAllocaPoisonCallVec) {
3171  const ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3172  assert(Desc.Offset % L.Granularity == 0);
3173  size_t Begin = Desc.Offset / L.Granularity;
3174  size_t End = Begin + (APC.Size + L.Granularity - 1) / L.Granularity;
3175 
3176  IRBuilder<> IRB(APC.InsBefore);
3177  copyToShadow(ShadowAfterScope,
3178  APC.DoPoison ? ShadowAfterScope : ShadowInScope, Begin, End,
3179  IRB, ShadowBase);
3180  }
3181  }
3182 
3183  SmallVector<uint8_t, 64> ShadowClean(ShadowAfterScope.size(), 0);
3184  SmallVector<uint8_t, 64> ShadowAfterReturn;
3185 
3186  // (Un)poison the stack before all ret instructions.
3187  for (auto Ret : RetVec) {
3188  IRBuilder<> IRBRet(Ret);
3189  // Mark the current frame as retired.
3191  BasePlus0);
3192  if (DoStackMalloc) {
3193  assert(StackMallocIdx >= 0);
3194  // if FakeStack != 0 // LocalStackBase == FakeStack
3195  // // In use-after-return mode, poison the whole stack frame.
3196  // if StackMallocIdx <= 4
3197  // // For small sizes inline the whole thing:
3198  // memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
3199  // **SavedFlagPtr(FakeStack) = 0
3200  // else
3201  // __asan_stack_free_N(FakeStack, LocalStackSize)
3202  // else
3203  // <This is not a fake stack; unpoison the redzones>
3204  Value *Cmp =
3205  IRBRet.CreateICmpNE(FakeStack, Constant::getNullValue(IntptrTy));
3206  Instruction *ThenTerm, *ElseTerm;
3207  SplitBlockAndInsertIfThenElse(Cmp, Ret, &ThenTerm, &ElseTerm);
3208 
3209  IRBuilder<> IRBPoison(ThenTerm);
3210  if (StackMallocIdx <= 4) {
3211  int ClassSize = kMinStackMallocSize << StackMallocIdx;
3212  ShadowAfterReturn.resize(ClassSize / L.Granularity,
3214  copyToShadow(ShadowAfterReturn, ShadowAfterReturn, IRBPoison,
3215  ShadowBase);
3216  Value *SavedFlagPtrPtr = IRBPoison.CreateAdd(
3217  FakeStack,
3218  ConstantInt::get(IntptrTy, ClassSize - ASan.LongSize / 8));
3219  Value *SavedFlagPtr = IRBPoison.CreateLoad(
3220  IntptrTy, IRBPoison.CreateIntToPtr(SavedFlagPtrPtr, IntptrPtrTy));
3221  IRBPoison.CreateStore(
3222  Constant::getNullValue(IRBPoison.getInt8Ty()),
3223  IRBPoison.CreateIntToPtr(SavedFlagPtr, IRBPoison.getInt8PtrTy()));
3224  } else {
3225  // For larger frames call __asan_stack_free_*.
3226  IRBPoison.CreateCall(
3227  AsanStackFreeFunc[StackMallocIdx],
3228  {FakeStack, ConstantInt::get(IntptrTy, LocalStackSize)});
3229  }
3230 
3231  IRBuilder<> IRBElse(ElseTerm);
3232  copyToShadow(ShadowAfterScope, ShadowClean, IRBElse, ShadowBase);
3233  } else {
3234  copyToShadow(ShadowAfterScope, ShadowClean, IRBRet, ShadowBase);
3235  }
3236  }
3237 
3238  // We are done. Remove the old unused alloca instructions.
3239  for (auto AI : AllocaVec) AI->eraseFromParent();
3240 }
3241 
3242 void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
3243  IRBuilder<> &IRB, bool DoPoison) {
3244  // For now just insert the call to ASan runtime.
3245  Value *AddrArg = IRB.CreatePointerCast(V, IntptrTy);
3246  Value *SizeArg = ConstantInt::get(IntptrTy, Size);
3247  IRB.CreateCall(
3248  DoPoison ? AsanPoisonStackMemoryFunc : AsanUnpoisonStackMemoryFunc,
3249  {AddrArg, SizeArg});
3250 }
3251 
3252 // Handling llvm.lifetime intrinsics for a given %alloca:
3253 // (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
3254 // (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
3255 // invalid accesses) and unpoison it for llvm.lifetime.start (the memory
3256 // could be poisoned by previous llvm.lifetime.end instruction, as the
3257 // variable may go in and out of scope several times, e.g. in loops).
3258 // (3) if we poisoned at least one %alloca in a function,
3259 // unpoison the whole stack frame at function exit.
3260 void FunctionStackPoisoner::handleDynamicAllocaCall(AllocaInst *AI) {
3261  IRBuilder<> IRB(AI);
3262 
3263  const unsigned Align = std::max(kAllocaRzSize, AI->getAlignment());
3264  const uint64_t AllocaRedzoneMask = kAllocaRzSize - 1;
3265 
3266  Value *Zero = Constant::getNullValue(IntptrTy);
3267  Value *AllocaRzSize = ConstantInt::get(IntptrTy, kAllocaRzSize);
3268  Value *AllocaRzMask = ConstantInt::get(IntptrTy, AllocaRedzoneMask);
3269 
3270  // Since we need to extend alloca with additional memory to locate
3271  // redzones, and OldSize is number of allocated blocks with
3272  // ElementSize size, get allocated memory size in bytes by
3273  // OldSize * ElementSize.
3274  const unsigned ElementSize =
3276  Value *OldSize =
3277  IRB.CreateMul(IRB.CreateIntCast(AI->getArraySize(), IntptrTy, false),
3278  ConstantInt::get(IntptrTy, ElementSize));
3279 
3280  // PartialSize = OldSize % 32
3281  Value *PartialSize = IRB.CreateAnd(OldSize, AllocaRzMask);
3282 
3283  // Misalign = kAllocaRzSize - PartialSize;
3284  Value *Misalign = IRB.CreateSub(AllocaRzSize, PartialSize);
3285 
3286  // PartialPadding = Misalign != kAllocaRzSize ? Misalign : 0;
3287  Value *Cond = IRB.CreateICmpNE(Misalign, AllocaRzSize);
3288  Value *PartialPadding = IRB.CreateSelect(Cond, Misalign, Zero);
3289 
3290  // AdditionalChunkSize = Align + PartialPadding + kAllocaRzSize
3291  // Align is added to locate left redzone, PartialPadding for possible
3292  // partial redzone and kAllocaRzSize for right redzone respectively.
3293  Value *AdditionalChunkSize = IRB.CreateAdd(
3294  ConstantInt::get(IntptrTy, Align + kAllocaRzSize), PartialPadding);
3295 
3296  Value *NewSize = IRB.CreateAdd(OldSize, AdditionalChunkSize);
3297 
3298  // Insert new alloca with new NewSize and Align params.
3299  AllocaInst *NewAlloca = IRB.CreateAlloca(IRB.getInt8Ty(), NewSize);
3300  NewAlloca->setAlignment(Align);
3301 
3302  // NewAddress = Address + Align
3303  Value *NewAddress = IRB.CreateAdd(IRB.CreatePtrToInt(NewAlloca, IntptrTy),
3304  ConstantInt::get(IntptrTy, Align));
3305 
3306  // Insert __asan_alloca_poison call for new created alloca.
3307  IRB.CreateCall(AsanAllocaPoisonFunc, {NewAddress, OldSize});
3308 
3309  // Store the last alloca's address to DynamicAllocaLayout. We'll need this
3310  // for unpoisoning stuff.
3311  IRB.CreateStore(IRB.CreatePtrToInt(NewAlloca, IntptrTy), DynamicAllocaLayout);
3312 
3313  Value *NewAddressPtr = IRB.CreateIntToPtr(NewAddress, AI->getType());
3314 
3315  // Replace all uses of AddessReturnedByAlloca with NewAddressPtr.
3316  AI->replaceAllUsesWith(NewAddressPtr);
3317 
3318  // We are done. Erase old alloca from parent.
3319  AI->eraseFromParent();
3320 }
3321 
3322 // isSafeAccess returns true if Addr is always inbounds with respect to its
3323 // base object. For example, it is a field access or an array access with
3324 // constant inbounds index.
3325 bool AddressSanitizer::isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis,
3326  Value *Addr, uint64_t TypeSize) const {
3327  SizeOffsetType SizeOffset = ObjSizeVis.compute(Addr);
3328  if (!ObjSizeVis.bothKnown(SizeOffset)) return false;
3329  uint64_t Size = SizeOffset.first.getZExtValue();
3330  int64_t Offset = SizeOffset.second.getSExtValue();
3331  // Three checks are required to ensure safety:
3332  // . Offset >= 0 (since the offset is given from the base ptr)
3333  // . Size >= Offset (unsigned)
3334  // . Size - Offset >= NeededSize (unsigned)
3335  return Offset >= 0 && Size >= uint64_t(Offset) &&
3336  Size - uint64_t(Offset) >= TypeSize / 8;
3337 }
void setVisibility(VisibilityTypes V)
Definition: GlobalValue.h:242
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:1298
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:94
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:59
static cl::opt< bool > ClStack("asan-stack", cl::desc("Handle stack memory"), cl::Hidden, cl::init(true))
bool isOSEmscripten() const
Tests whether the OS is Emscripten.
Definition: Triple.h:606
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Definition: DataLayout.h:111
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:453
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:258
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:67
bool hasLocalLinkage() const
Definition: GlobalValue.h:445
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:714
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:1563
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))
Value * CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2106
NodeTy * getNextNode()
Get the next node, or nullptr for the list tail.
Definition: ilist_node.h:288
bool hasPrivateLinkage() const
Definition: GlobalValue.h:444
PassT::Result & getResult(IRUnitT &IR, ExtraArgTs... ExtraArgs)
Get the result of an analysis pass for a given IR unit.
Definition: PassManager.h:776
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:1576
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:530
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:165
LLVM_NODISCARD bool startswith(StringRef Prefix) const
Check if this string starts with the given Prefix.
Definition: StringRef.h:270
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:632
static const char *const kODRGenPrefix
static Constant * getIntToPtr(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1791
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:472
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:429
bool hasFnAttribute(Attribute::AttrKind Kind) const
Return true if the function has the attribute.
Definition: Function.h:323
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:389
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:580
bool isOSFuchsia() const
Definition: Triple.h:505
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:693
This defines the Use class.
void reserve(size_type N)
Definition: SmallVector.h:369
void setAlignment(unsigned Align)
FIXME: Remove this setter once the migration to MaybeAlign is over.
Definition: Globals.cpp:116
Tentative definitions.
Definition: GlobalValue.h:58
static Constant * get(ArrayType *T, ArrayRef< Constant *> V)
Definition: Constants.cpp:1014
static cl::opt< bool > ClInsertVersionCheck("asan-guard-against-version-mismatch", cl::desc("Guard against compiler/runtime version mismatch."), cl::Hidden, cl::init(true))
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:289
StoreInst * CreateAlignedStore(Value *Val, Value *Ptr, unsigned Align, bool isVolatile=false)
Definition: IRBuilder.h:1649
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:383
Value * getArgOperand(unsigned i) const
Definition: InstrTypes.h:1241
static const uint64_t kDefaultShadowScale
unsigned 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
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:388
PointerType * getType() const
Overload to return most specific pointer type.
Definition: Instructions.h:96
Class to represent struct types.
Definition: DerivedTypes.h:233
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:654
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:779
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
bool hasMetadata() const
Return true if this instruction has any metadata attached to it.
Definition: Instruction.h:224
Value * CreateAdd(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1118
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:140
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:416
StoreInst * CreateStore(Value *Val, Value *Ptr, bool isVolatile=false)
Definition: IRBuilder.h:1605
Value * CreateIntToPtr(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1959
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 uint64_t GetCtorAndDtorPriority(Triple &TargetTriple)
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:245
SmallVector< uint8_t, 64 > GetShadowBytesAfterScope(const SmallVectorImpl< ASanStackVariableDescription > &Vars, const ASanStackFrameLayout &Layout)
std::string itostr(int64_t X)
Definition: StringExtras.h:238
ConstantDataSequential - A vector or array constant whose element type is a simple 1/2/4/8-byte integ...
Definition: Constants.h: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:754
ArchType getArch() const
getArch - Get the parsed architecture type of this triple.
Definition: Triple.h:296
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:403
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 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:107
static cl::opt< bool > ClInvalidPointerSub("asan-detect-invalid-pointer-sub", cl::desc("Instrument - operations with pointer operands"), cl::Hidden, cl::init(false))
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)
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:233
static const uint64_t kWindowsShadowOffset64
iterator_range< User::op_iterator > arg_operands()
Definition: InstrTypes.h:1233
Value * CreateSub(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1135
bool isiOS() const
Is this an iOS triple.
Definition: Triple.h:462
An instruction for storing to memory.
Definition: Instructions.h:320
void SetCurrentDebugLocation(DebugLoc L)
Set location information used by debugging information.
Definition: IRBuilder.h:156
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:460
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:493
Debug location.
void takeName(Value *V)
Transfer the name from V to this value.
Definition: Value.cpp:291
iterator begin()
Definition: Function.h:680
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:1057
void SetInsertPoint(BasicBlock *TheBB)
This specifies that created instructions should be appended to the end of the specified block...
Definition: IRBuilder.h:132
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:354
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:1294
Constant * getAggregateElement(unsigned Elt) const
For aggregates (struct/array/vector) return the constant that corresponds to the specified element if...
Definition: Constants.cpp:359
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:538
ExternalWeak linkage description.
Definition: GlobalValue.h:57
const BasicBlock & getEntryBlock() const
Definition: Function.h:664
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:432
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
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:328
DLLStorageClassTypes getDLLStorageClass() const
Definition: GlobalValue.h:262
VisibilityTypes getVisibility() const
Definition: GlobalValue.h:236
static const uint64_t kEmscriptenShadowOffset
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:251
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:302
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:1504
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:1356
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:2285
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
static bool isInterestingPointerSubtraction(Instruction *I)
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:299
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
AllocaInst * findAllocaForValue(Value *V, DenseMap< Value *, AllocaInst *> &AllocaForValue)
Finds alloca where the value comes from.
bool isAndroidVersionLT(unsigned Major) const
Definition: Triple.h:663
Frontend-provided metadata for global variables.
bool isPS4CPU() const
Tests whether the target is the PS4 CPU.
Definition: Triple.h:648
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:2130
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:1075
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:2102
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:446
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:2307
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
static cl::opt< bool > ClInvalidPointerCmp("asan-detect-invalid-pointer-cmp", cl::desc("Instrument <, <=, >, >= with pointer operands"), cl::Hidden, cl::init(false))
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:421
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:1152
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:40
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:2232
Value * CreateGEP(Value *Ptr, ArrayRef< Value *> IdxList, const Twine &Name="")
Definition: IRBuilder.h:1677
static Constant * getPointerCast(Constant *C, Type *Ty)
Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant expression.
Definition: Constants.cpp:1618
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:1160
Value * CreateIntCast(Value *V, Type *DestTy, bool isSigned, const Twine &Name="")
Definition: IRBuilder.h:2033
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:86
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:837
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:752
const DataFlowGraph & G
Definition: RDFGraph.cpp:202
bool isOSLinux() const
Tests whether the OS is Linux.
Definition: Triple.h:586
static const uint64_t kDefaultShadowOffset64
ConstantInt * getInt32(uint32_t C)
Get a constant 32-bit value.
Definition: IRBuilder.h:343
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:482
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:653
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:63
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:454
bool isOSFreeBSD() const
Definition: Triple.h:501
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:481
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:373
static const uint64_t kAsanEmscriptenCtorAndDtorPriority
Value * CreatePointerCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:2010
bool hasComdat() const
Definition: GlobalObject.h:104
void initializeAddressSanitizerLegacyPassPass(PassRegistry &)
void setMetadata(unsigned KindID, MDNode *MD)
Set a particular kind of metadata attachment.
Definition: Metadata.cpp:1430
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:105
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:470
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:709
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:1239
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:331
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:219
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:694
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:416
void copyAttributesFrom(const GlobalVariable *Src)
copyAttributesFrom - copy all additional attributes (those not needed to create a GlobalVariable) fro...
Definition: Globals.cpp:411
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:582
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:332
Type * getValueType() const
Definition: GlobalValue.h:279
const BasicBlockListType & getBasicBlockList() const
Get the underlying elements of the Function...
Definition: Function.h:657
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:2897
CallInst * CreateCall(FunctionType *FTy, Value *Callee, ArrayRef< Value *> Args=None, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:2237
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 bool isInterestingPointerComparison(Instruction *I)
static const char *const kAsanModuleDtorName
Value * CreateAnd(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1268
Value * CreatePtrToInt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1954
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:136
bool isArrayAllocation() const
Return true if there is an allocation size parameter to the allocation instruction that is not 1...
bool replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress, DIBuilder &Builder, uint8_t DIExprFlags, int Offset)
Replaces llvm.dbg.declare instruction when the alloca it describes is replaced with a new value...
Definition: Local.cpp:1559
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
const BasicBlock & front() const
Definition: Function.h:687
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:575
LLVM Value Representation.
Definition: Value.h:73
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:510
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:661
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:1228
void addDebugInfo(DIGlobalVariableExpression *GV)
Attach a DIGlobalVariableExpression.
Definition: Metadata.cpp:1517
bool isThreadLocal() const
If the value is "Thread Local", its value isn&#39;t shared by the threads.
Definition: GlobalValue.h:250
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
static cl::opt< uint64_t > ClMappingOffset("asan-mapping-offset", cl::desc("offset of asan shadow mapping [EXPERIMENTAL]"), cl::Hidden, cl::init(0))
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:984
void setSection(StringRef S)
Change the section for this global.
Definition: Globals.cpp:215
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:485
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:699
iterator_range< arg_iterator > args()
Definition: Function.h:719
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