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MemorySanitizer.cpp
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1 //===- MemorySanitizer.cpp - detector of uninitialized reads --------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 /// \file
11 /// This file is a part of MemorySanitizer, a detector of uninitialized
12 /// reads.
13 ///
14 /// The algorithm of the tool is similar to Memcheck
15 /// (http://goo.gl/QKbem). We associate a few shadow bits with every
16 /// byte of the application memory, poison the shadow of the malloc-ed
17 /// or alloca-ed memory, load the shadow bits on every memory read,
18 /// propagate the shadow bits through some of the arithmetic
19 /// instruction (including MOV), store the shadow bits on every memory
20 /// write, report a bug on some other instructions (e.g. JMP) if the
21 /// associated shadow is poisoned.
22 ///
23 /// But there are differences too. The first and the major one:
24 /// compiler instrumentation instead of binary instrumentation. This
25 /// gives us much better register allocation, possible compiler
26 /// optimizations and a fast start-up. But this brings the major issue
27 /// as well: msan needs to see all program events, including system
28 /// calls and reads/writes in system libraries, so we either need to
29 /// compile *everything* with msan or use a binary translation
30 /// component (e.g. DynamoRIO) to instrument pre-built libraries.
31 /// Another difference from Memcheck is that we use 8 shadow bits per
32 /// byte of application memory and use a direct shadow mapping. This
33 /// greatly simplifies the instrumentation code and avoids races on
34 /// shadow updates (Memcheck is single-threaded so races are not a
35 /// concern there. Memcheck uses 2 shadow bits per byte with a slow
36 /// path storage that uses 8 bits per byte).
37 ///
38 /// The default value of shadow is 0, which means "clean" (not poisoned).
39 ///
40 /// Every module initializer should call __msan_init to ensure that the
41 /// shadow memory is ready. On error, __msan_warning is called. Since
42 /// parameters and return values may be passed via registers, we have a
43 /// specialized thread-local shadow for return values
44 /// (__msan_retval_tls) and parameters (__msan_param_tls).
45 ///
46 /// Origin tracking.
47 ///
48 /// MemorySanitizer can track origins (allocation points) of all uninitialized
49 /// values. This behavior is controlled with a flag (msan-track-origins) and is
50 /// disabled by default.
51 ///
52 /// Origins are 4-byte values created and interpreted by the runtime library.
53 /// They are stored in a second shadow mapping, one 4-byte value for 4 bytes
54 /// of application memory. Propagation of origins is basically a bunch of
55 /// "select" instructions that pick the origin of a dirty argument, if an
56 /// instruction has one.
57 ///
58 /// Every 4 aligned, consecutive bytes of application memory have one origin
59 /// value associated with them. If these bytes contain uninitialized data
60 /// coming from 2 different allocations, the last store wins. Because of this,
61 /// MemorySanitizer reports can show unrelated origins, but this is unlikely in
62 /// practice.
63 ///
64 /// Origins are meaningless for fully initialized values, so MemorySanitizer
65 /// avoids storing origin to memory when a fully initialized value is stored.
66 /// This way it avoids needless overwritting origin of the 4-byte region on
67 /// a short (i.e. 1 byte) clean store, and it is also good for performance.
68 ///
69 /// Atomic handling.
70 ///
71 /// Ideally, every atomic store of application value should update the
72 /// corresponding shadow location in an atomic way. Unfortunately, atomic store
73 /// of two disjoint locations can not be done without severe slowdown.
74 ///
75 /// Therefore, we implement an approximation that may err on the safe side.
76 /// In this implementation, every atomically accessed location in the program
77 /// may only change from (partially) uninitialized to fully initialized, but
78 /// not the other way around. We load the shadow _after_ the application load,
79 /// and we store the shadow _before_ the app store. Also, we always store clean
80 /// shadow (if the application store is atomic). This way, if the store-load
81 /// pair constitutes a happens-before arc, shadow store and load are correctly
82 /// ordered such that the load will get either the value that was stored, or
83 /// some later value (which is always clean).
84 ///
85 /// This does not work very well with Compare-And-Swap (CAS) and
86 /// Read-Modify-Write (RMW) operations. To follow the above logic, CAS and RMW
87 /// must store the new shadow before the app operation, and load the shadow
88 /// after the app operation. Computers don't work this way. Current
89 /// implementation ignores the load aspect of CAS/RMW, always returning a clean
90 /// value. It implements the store part as a simple atomic store by storing a
91 /// clean shadow.
92 //
93 //===----------------------------------------------------------------------===//
94 
95 #include "llvm/ADT/APInt.h"
96 #include "llvm/ADT/ArrayRef.h"
98 #include "llvm/ADT/SmallString.h"
99 #include "llvm/ADT/SmallVector.h"
100 #include "llvm/ADT/StringExtras.h"
101 #include "llvm/ADT/StringRef.h"
102 #include "llvm/ADT/Triple.h"
105 #include "llvm/IR/Argument.h"
106 #include "llvm/IR/Attributes.h"
107 #include "llvm/IR/BasicBlock.h"
108 #include "llvm/IR/CallSite.h"
109 #include "llvm/IR/CallingConv.h"
110 #include "llvm/IR/Constant.h"
111 #include "llvm/IR/Constants.h"
112 #include "llvm/IR/DataLayout.h"
113 #include "llvm/IR/DerivedTypes.h"
114 #include "llvm/IR/Function.h"
115 #include "llvm/IR/GlobalValue.h"
116 #include "llvm/IR/GlobalVariable.h"
117 #include "llvm/IR/IRBuilder.h"
118 #include "llvm/IR/InlineAsm.h"
119 #include "llvm/IR/InstVisitor.h"
120 #include "llvm/IR/InstrTypes.h"
121 #include "llvm/IR/Instruction.h"
122 #include "llvm/IR/Instructions.h"
123 #include "llvm/IR/IntrinsicInst.h"
124 #include "llvm/IR/Intrinsics.h"
125 #include "llvm/IR/LLVMContext.h"
126 #include "llvm/IR/MDBuilder.h"
127 #include "llvm/IR/Module.h"
128 #include "llvm/IR/Type.h"
129 #include "llvm/IR/Value.h"
130 #include "llvm/IR/ValueMap.h"
131 #include "llvm/Pass.h"
133 #include "llvm/Support/Casting.h"
135 #include "llvm/Support/Compiler.h"
136 #include "llvm/Support/Debug.h"
138 #include "llvm/Support/MathExtras.h"
143 #include <algorithm>
144 #include <cassert>
145 #include <cstddef>
146 #include <cstdint>
147 #include <memory>
148 #include <string>
149 #include <tuple>
150 
151 using namespace llvm;
152 
153 #define DEBUG_TYPE "msan"
154 
155 static const unsigned kOriginSize = 4;
156 static const unsigned kMinOriginAlignment = 4;
157 static const unsigned kShadowTLSAlignment = 8;
158 
159 // These constants must be kept in sync with the ones in msan.h.
160 static const unsigned kParamTLSSize = 800;
161 static const unsigned kRetvalTLSSize = 800;
162 
163 // Accesses sizes are powers of two: 1, 2, 4, 8.
164 static const size_t kNumberOfAccessSizes = 4;
165 
166 /// \brief Track origins of uninitialized values.
167 ///
168 /// Adds a section to MemorySanitizer report that points to the allocation
169 /// (stack or heap) the uninitialized bits came from originally.
170 static cl::opt<int> ClTrackOrigins("msan-track-origins",
171  cl::desc("Track origins (allocation sites) of poisoned memory"),
172  cl::Hidden, cl::init(0));
173 
174 static cl::opt<bool> ClKeepGoing("msan-keep-going",
175  cl::desc("keep going after reporting a UMR"),
176  cl::Hidden, cl::init(false));
177 
178 static cl::opt<bool> ClPoisonStack("msan-poison-stack",
179  cl::desc("poison uninitialized stack variables"),
180  cl::Hidden, cl::init(true));
181 
182 static cl::opt<bool> ClPoisonStackWithCall("msan-poison-stack-with-call",
183  cl::desc("poison uninitialized stack variables with a call"),
184  cl::Hidden, cl::init(false));
185 
186 static cl::opt<int> ClPoisonStackPattern("msan-poison-stack-pattern",
187  cl::desc("poison uninitialized stack variables with the given pattern"),
188  cl::Hidden, cl::init(0xff));
189 
190 static cl::opt<bool> ClPoisonUndef("msan-poison-undef",
191  cl::desc("poison undef temps"),
192  cl::Hidden, cl::init(true));
193 
194 static cl::opt<bool> ClHandleICmp("msan-handle-icmp",
195  cl::desc("propagate shadow through ICmpEQ and ICmpNE"),
196  cl::Hidden, cl::init(true));
197 
198 static cl::opt<bool> ClHandleICmpExact("msan-handle-icmp-exact",
199  cl::desc("exact handling of relational integer ICmp"),
200  cl::Hidden, cl::init(false));
201 
202 // When compiling the Linux kernel, we sometimes see false positives related to
203 // MSan being unable to understand that inline assembly calls may initialize
204 // local variables.
205 // This flag makes the compiler conservatively unpoison every memory location
206 // passed into an assembly call. Note that this may cause false positives.
207 // Because it's impossible to figure out the array sizes, we can only unpoison
208 // the first sizeof(type) bytes for each type* pointer.
210  "msan-handle-asm-conservative",
211  cl::desc("conservative handling of inline assembly"), cl::Hidden,
212  cl::init(false));
213 
214 // This flag controls whether we check the shadow of the address
215 // operand of load or store. Such bugs are very rare, since load from
216 // a garbage address typically results in SEGV, but still happen
217 // (e.g. only lower bits of address are garbage, or the access happens
218 // early at program startup where malloc-ed memory is more likely to
219 // be zeroed. As of 2012-08-28 this flag adds 20% slowdown.
220 static cl::opt<bool> ClCheckAccessAddress("msan-check-access-address",
221  cl::desc("report accesses through a pointer which has poisoned shadow"),
222  cl::Hidden, cl::init(true));
223 
224 static cl::opt<bool> ClDumpStrictInstructions("msan-dump-strict-instructions",
225  cl::desc("print out instructions with default strict semantics"),
226  cl::Hidden, cl::init(false));
227 
229  "msan-instrumentation-with-call-threshold",
230  cl::desc(
231  "If the function being instrumented requires more than "
232  "this number of checks and origin stores, use callbacks instead of "
233  "inline checks (-1 means never use callbacks)."),
234  cl::Hidden, cl::init(3500));
235 
236 // This is an experiment to enable handling of cases where shadow is a non-zero
237 // compile-time constant. For some unexplainable reason they were silently
238 // ignored in the instrumentation.
239 static cl::opt<bool> ClCheckConstantShadow("msan-check-constant-shadow",
240  cl::desc("Insert checks for constant shadow values"),
241  cl::Hidden, cl::init(false));
242 
243 // This is off by default because of a bug in gold:
244 // https://sourceware.org/bugzilla/show_bug.cgi?id=19002
245 static cl::opt<bool> ClWithComdat("msan-with-comdat",
246  cl::desc("Place MSan constructors in comdat sections"),
247  cl::Hidden, cl::init(false));
248 
249 // These options allow to specify custom memory map parameters
250 // See MemoryMapParams for details.
251 static cl::opt<unsigned long long> ClAndMask("msan-and-mask",
252  cl::desc("Define custom MSan AndMask"),
253  cl::Hidden, cl::init(0));
254 
255 static cl::opt<unsigned long long> ClXorMask("msan-xor-mask",
256  cl::desc("Define custom MSan XorMask"),
257  cl::Hidden, cl::init(0));
258 
259 static cl::opt<unsigned long long> ClShadowBase("msan-shadow-base",
260  cl::desc("Define custom MSan ShadowBase"),
261  cl::Hidden, cl::init(0));
262 
263 static cl::opt<unsigned long long> ClOriginBase("msan-origin-base",
264  cl::desc("Define custom MSan OriginBase"),
265  cl::Hidden, cl::init(0));
266 
267 static const char *const kMsanModuleCtorName = "msan.module_ctor";
268 static const char *const kMsanInitName = "__msan_init";
269 
270 namespace {
271 
272 // Memory map parameters used in application-to-shadow address calculation.
273 // Offset = (Addr & ~AndMask) ^ XorMask
274 // Shadow = ShadowBase + Offset
275 // Origin = OriginBase + Offset
276 struct MemoryMapParams {
277  uint64_t AndMask;
278  uint64_t XorMask;
279  uint64_t ShadowBase;
280  uint64_t OriginBase;
281 };
282 
283 struct PlatformMemoryMapParams {
284  const MemoryMapParams *bits32;
285  const MemoryMapParams *bits64;
286 };
287 
288 } // end anonymous namespace
289 
290 // i386 Linux
291 static const MemoryMapParams Linux_I386_MemoryMapParams = {
292  0x000080000000, // AndMask
293  0, // XorMask (not used)
294  0, // ShadowBase (not used)
295  0x000040000000, // OriginBase
296 };
297 
298 // x86_64 Linux
299 static const MemoryMapParams Linux_X86_64_MemoryMapParams = {
300 #ifdef MSAN_LINUX_X86_64_OLD_MAPPING
301  0x400000000000, // AndMask
302  0, // XorMask (not used)
303  0, // ShadowBase (not used)
304  0x200000000000, // OriginBase
305 #else
306  0, // AndMask (not used)
307  0x500000000000, // XorMask
308  0, // ShadowBase (not used)
309  0x100000000000, // OriginBase
310 #endif
311 };
312 
313 // mips64 Linux
314 static const MemoryMapParams Linux_MIPS64_MemoryMapParams = {
315  0, // AndMask (not used)
316  0x008000000000, // XorMask
317  0, // ShadowBase (not used)
318  0x002000000000, // OriginBase
319 };
320 
321 // ppc64 Linux
322 static const MemoryMapParams Linux_PowerPC64_MemoryMapParams = {
323  0xE00000000000, // AndMask
324  0x100000000000, // XorMask
325  0x080000000000, // ShadowBase
326  0x1C0000000000, // OriginBase
327 };
328 
329 // aarch64 Linux
330 static const MemoryMapParams Linux_AArch64_MemoryMapParams = {
331  0, // AndMask (not used)
332  0x06000000000, // XorMask
333  0, // ShadowBase (not used)
334  0x01000000000, // OriginBase
335 };
336 
337 // i386 FreeBSD
338 static const MemoryMapParams FreeBSD_I386_MemoryMapParams = {
339  0x000180000000, // AndMask
340  0x000040000000, // XorMask
341  0x000020000000, // ShadowBase
342  0x000700000000, // OriginBase
343 };
344 
345 // x86_64 FreeBSD
346 static const MemoryMapParams FreeBSD_X86_64_MemoryMapParams = {
347  0xc00000000000, // AndMask
348  0x200000000000, // XorMask
349  0x100000000000, // ShadowBase
350  0x380000000000, // OriginBase
351 };
352 
353 // x86_64 NetBSD
354 static const MemoryMapParams NetBSD_X86_64_MemoryMapParams = {
355  0, // AndMask
356  0x500000000000, // XorMask
357  0, // ShadowBase
358  0x100000000000, // OriginBase
359 };
360 
361 static const PlatformMemoryMapParams Linux_X86_MemoryMapParams = {
364 };
365 
366 static const PlatformMemoryMapParams Linux_MIPS_MemoryMapParams = {
367  nullptr,
369 };
370 
371 static const PlatformMemoryMapParams Linux_PowerPC_MemoryMapParams = {
372  nullptr,
374 };
375 
376 static const PlatformMemoryMapParams Linux_ARM_MemoryMapParams = {
377  nullptr,
379 };
380 
381 static const PlatformMemoryMapParams FreeBSD_X86_MemoryMapParams = {
384 };
385 
386 static const PlatformMemoryMapParams NetBSD_X86_MemoryMapParams = {
387  nullptr,
389 };
390 
391 namespace {
392 
393 /// \brief An instrumentation pass implementing detection of uninitialized
394 /// reads.
395 ///
396 /// MemorySanitizer: instrument the code in module to find
397 /// uninitialized reads.
398 class MemorySanitizer : public FunctionPass {
399 public:
400  // Pass identification, replacement for typeid.
401  static char ID;
402 
403  MemorySanitizer(int TrackOrigins = 0, bool Recover = false)
404  : FunctionPass(ID),
405  TrackOrigins(std::max(TrackOrigins, (int)ClTrackOrigins)),
406  Recover(Recover || ClKeepGoing) {}
407 
408  StringRef getPassName() const override { return "MemorySanitizer"; }
409 
410  void getAnalysisUsage(AnalysisUsage &AU) const override {
412  }
413 
414  bool runOnFunction(Function &F) override;
415  bool doInitialization(Module &M) override;
416 
417 private:
418  friend struct MemorySanitizerVisitor;
419  friend struct VarArgAMD64Helper;
420  friend struct VarArgMIPS64Helper;
421  friend struct VarArgAArch64Helper;
422  friend struct VarArgPowerPC64Helper;
423 
424  void initializeCallbacks(Module &M);
425 
426  /// \brief Track origins (allocation points) of uninitialized values.
427  int TrackOrigins;
428  bool Recover;
429 
430  LLVMContext *C;
431  Type *IntptrTy;
432  Type *OriginTy;
433 
434  /// \brief Thread-local shadow storage for function parameters.
435  GlobalVariable *ParamTLS;
436 
437  /// \brief Thread-local origin storage for function parameters.
438  GlobalVariable *ParamOriginTLS;
439 
440  /// \brief Thread-local shadow storage for function return value.
441  GlobalVariable *RetvalTLS;
442 
443  /// \brief Thread-local origin storage for function return value.
444  GlobalVariable *RetvalOriginTLS;
445 
446  /// \brief Thread-local shadow storage for in-register va_arg function
447  /// parameters (x86_64-specific).
448  GlobalVariable *VAArgTLS;
449 
450  /// \brief Thread-local shadow storage for va_arg overflow area
451  /// (x86_64-specific).
452  GlobalVariable *VAArgOverflowSizeTLS;
453 
454  /// \brief Thread-local space used to pass origin value to the UMR reporting
455  /// function.
456  GlobalVariable *OriginTLS;
457 
458  /// \brief The run-time callback to print a warning.
459  Value *WarningFn = nullptr;
460 
461  // These arrays are indexed by log2(AccessSize).
462  Value *MaybeWarningFn[kNumberOfAccessSizes];
463  Value *MaybeStoreOriginFn[kNumberOfAccessSizes];
464 
465  /// \brief Run-time helper that generates a new origin value for a stack
466  /// allocation.
467  Value *MsanSetAllocaOrigin4Fn;
468 
469  /// \brief Run-time helper that poisons stack on function entry.
470  Value *MsanPoisonStackFn;
471 
472  /// \brief Run-time helper that records a store (or any event) of an
473  /// uninitialized value and returns an updated origin id encoding this info.
474  Value *MsanChainOriginFn;
475 
476  /// \brief MSan runtime replacements for memmove, memcpy and memset.
477  Value *MemmoveFn, *MemcpyFn, *MemsetFn;
478 
479  /// \brief Memory map parameters used in application-to-shadow calculation.
480  const MemoryMapParams *MapParams;
481 
482  /// \brief Custom memory map parameters used when -msan-shadow-base or
483  // -msan-origin-base is provided.
484  MemoryMapParams CustomMapParams;
485 
486  MDNode *ColdCallWeights;
487 
488  /// \brief Branch weights for origin store.
489  MDNode *OriginStoreWeights;
490 
491  /// \brief An empty volatile inline asm that prevents callback merge.
492  InlineAsm *EmptyAsm;
493 
494  Function *MsanCtorFunction;
495 };
496 
497 } // end anonymous namespace
498 
499 char MemorySanitizer::ID = 0;
500 
502  MemorySanitizer, "msan",
503  "MemorySanitizer: detects uninitialized reads.", false, false)
506  MemorySanitizer, "msan",
507  "MemorySanitizer: detects uninitialized reads.", false, false)
508 
509 FunctionPass *llvm::createMemorySanitizerPass(int TrackOrigins, bool Recover) {
510  return new MemorySanitizer(TrackOrigins, Recover);
511 }
512 
513 /// \brief Create a non-const global initialized with the given string.
514 ///
515 /// Creates a writable global for Str so that we can pass it to the
516 /// run-time lib. Runtime uses first 4 bytes of the string to store the
517 /// frame ID, so the string needs to be mutable.
519  StringRef Str) {
520  Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
521  return new GlobalVariable(M, StrConst->getType(), /*isConstant=*/false,
522  GlobalValue::PrivateLinkage, StrConst, "");
523 }
524 
525 /// \brief Insert extern declaration of runtime-provided functions and globals.
526 void MemorySanitizer::initializeCallbacks(Module &M) {
527  // Only do this once.
528  if (WarningFn)
529  return;
530 
531  IRBuilder<> IRB(*C);
532  // Create the callback.
533  // FIXME: this function should have "Cold" calling conv,
534  // which is not yet implemented.
535  StringRef WarningFnName = Recover ? "__msan_warning"
536  : "__msan_warning_noreturn";
537  WarningFn = M.getOrInsertFunction(WarningFnName, IRB.getVoidTy());
538 
539  for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
540  AccessSizeIndex++) {
541  unsigned AccessSize = 1 << AccessSizeIndex;
542  std::string FunctionName = "__msan_maybe_warning_" + itostr(AccessSize);
543  MaybeWarningFn[AccessSizeIndex] = M.getOrInsertFunction(
544  FunctionName, IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8),
545  IRB.getInt32Ty());
546 
547  FunctionName = "__msan_maybe_store_origin_" + itostr(AccessSize);
548  MaybeStoreOriginFn[AccessSizeIndex] = M.getOrInsertFunction(
549  FunctionName, IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8),
550  IRB.getInt8PtrTy(), IRB.getInt32Ty());
551  }
552 
553  MsanSetAllocaOrigin4Fn = M.getOrInsertFunction(
554  "__msan_set_alloca_origin4", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy,
555  IRB.getInt8PtrTy(), IntptrTy);
556  MsanPoisonStackFn =
557  M.getOrInsertFunction("__msan_poison_stack", IRB.getVoidTy(),
558  IRB.getInt8PtrTy(), IntptrTy);
559  MsanChainOriginFn = M.getOrInsertFunction(
560  "__msan_chain_origin", IRB.getInt32Ty(), IRB.getInt32Ty());
561  MemmoveFn = M.getOrInsertFunction(
562  "__msan_memmove", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
563  IRB.getInt8PtrTy(), IntptrTy);
564  MemcpyFn = M.getOrInsertFunction(
565  "__msan_memcpy", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
566  IntptrTy);
567  MemsetFn = M.getOrInsertFunction(
568  "__msan_memset", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt32Ty(),
569  IntptrTy);
570 
571  // Create globals.
572  RetvalTLS = new GlobalVariable(
573  M, ArrayType::get(IRB.getInt64Ty(), kRetvalTLSSize / 8), false,
574  GlobalVariable::ExternalLinkage, nullptr, "__msan_retval_tls", nullptr,
576  RetvalOriginTLS = new GlobalVariable(
577  M, OriginTy, false, GlobalVariable::ExternalLinkage, nullptr,
578  "__msan_retval_origin_tls", nullptr, GlobalVariable::InitialExecTLSModel);
579 
580  ParamTLS = new GlobalVariable(
581  M, ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), false,
582  GlobalVariable::ExternalLinkage, nullptr, "__msan_param_tls", nullptr,
584  ParamOriginTLS = new GlobalVariable(
585  M, ArrayType::get(OriginTy, kParamTLSSize / 4), false,
586  GlobalVariable::ExternalLinkage, nullptr, "__msan_param_origin_tls",
588 
589  VAArgTLS = new GlobalVariable(
590  M, ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), false,
591  GlobalVariable::ExternalLinkage, nullptr, "__msan_va_arg_tls", nullptr,
593  VAArgOverflowSizeTLS = new GlobalVariable(
594  M, IRB.getInt64Ty(), false, GlobalVariable::ExternalLinkage, nullptr,
595  "__msan_va_arg_overflow_size_tls", nullptr,
597  OriginTLS = new GlobalVariable(
598  M, IRB.getInt32Ty(), false, GlobalVariable::ExternalLinkage, nullptr,
599  "__msan_origin_tls", nullptr, GlobalVariable::InitialExecTLSModel);
600 
601  // We insert an empty inline asm after __msan_report* to avoid callback merge.
602  EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
603  StringRef(""), StringRef(""),
604  /*hasSideEffects=*/true);
605 }
606 
607 /// \brief Module-level initialization.
608 ///
609 /// inserts a call to __msan_init to the module's constructor list.
610 bool MemorySanitizer::doInitialization(Module &M) {
611  auto &DL = M.getDataLayout();
612 
613  bool ShadowPassed = ClShadowBase.getNumOccurrences() > 0;
614  bool OriginPassed = ClOriginBase.getNumOccurrences() > 0;
615  // Check the overrides first
616  if (ShadowPassed || OriginPassed) {
617  CustomMapParams.AndMask = ClAndMask;
618  CustomMapParams.XorMask = ClXorMask;
619  CustomMapParams.ShadowBase = ClShadowBase;
620  CustomMapParams.OriginBase = ClOriginBase;
621  MapParams = &CustomMapParams;
622  } else {
623  Triple TargetTriple(M.getTargetTriple());
624  switch (TargetTriple.getOS()) {
625  case Triple::FreeBSD:
626  switch (TargetTriple.getArch()) {
627  case Triple::x86_64:
628  MapParams = FreeBSD_X86_MemoryMapParams.bits64;
629  break;
630  case Triple::x86:
631  MapParams = FreeBSD_X86_MemoryMapParams.bits32;
632  break;
633  default:
634  report_fatal_error("unsupported architecture");
635  }
636  break;
637  case Triple::NetBSD:
638  switch (TargetTriple.getArch()) {
639  case Triple::x86_64:
640  MapParams = NetBSD_X86_MemoryMapParams.bits64;
641  break;
642  default:
643  report_fatal_error("unsupported architecture");
644  }
645  break;
646  case Triple::Linux:
647  switch (TargetTriple.getArch()) {
648  case Triple::x86_64:
649  MapParams = Linux_X86_MemoryMapParams.bits64;
650  break;
651  case Triple::x86:
652  MapParams = Linux_X86_MemoryMapParams.bits32;
653  break;
654  case Triple::mips64:
655  case Triple::mips64el:
656  MapParams = Linux_MIPS_MemoryMapParams.bits64;
657  break;
658  case Triple::ppc64:
659  case Triple::ppc64le:
660  MapParams = Linux_PowerPC_MemoryMapParams.bits64;
661  break;
662  case Triple::aarch64:
663  case Triple::aarch64_be:
664  MapParams = Linux_ARM_MemoryMapParams.bits64;
665  break;
666  default:
667  report_fatal_error("unsupported architecture");
668  }
669  break;
670  default:
671  report_fatal_error("unsupported operating system");
672  }
673  }
674 
675  C = &(M.getContext());
676  IRBuilder<> IRB(*C);
677  IntptrTy = IRB.getIntPtrTy(DL);
678  OriginTy = IRB.getInt32Ty();
679 
680  ColdCallWeights = MDBuilder(*C).createBranchWeights(1, 1000);
681  OriginStoreWeights = MDBuilder(*C).createBranchWeights(1, 1000);
682 
683  std::tie(MsanCtorFunction, std::ignore) =
685  /*InitArgTypes=*/{},
686  /*InitArgs=*/{});
687  if (ClWithComdat) {
688  Comdat *MsanCtorComdat = M.getOrInsertComdat(kMsanModuleCtorName);
689  MsanCtorFunction->setComdat(MsanCtorComdat);
690  appendToGlobalCtors(M, MsanCtorFunction, 0, MsanCtorFunction);
691  } else {
692  appendToGlobalCtors(M, MsanCtorFunction, 0);
693  }
694 
695 
696  if (TrackOrigins)
698  IRB.getInt32(TrackOrigins), "__msan_track_origins");
699 
700  if (Recover)
702  IRB.getInt32(Recover), "__msan_keep_going");
703 
704  return true;
705 }
706 
707 namespace {
708 
709 /// \brief A helper class that handles instrumentation of VarArg
710 /// functions on a particular platform.
711 ///
712 /// Implementations are expected to insert the instrumentation
713 /// necessary to propagate argument shadow through VarArg function
714 /// calls. Visit* methods are called during an InstVisitor pass over
715 /// the function, and should avoid creating new basic blocks. A new
716 /// instance of this class is created for each instrumented function.
717 struct VarArgHelper {
718  virtual ~VarArgHelper() = default;
719 
720  /// \brief Visit a CallSite.
721  virtual void visitCallSite(CallSite &CS, IRBuilder<> &IRB) = 0;
722 
723  /// \brief Visit a va_start call.
724  virtual void visitVAStartInst(VAStartInst &I) = 0;
725 
726  /// \brief Visit a va_copy call.
727  virtual void visitVACopyInst(VACopyInst &I) = 0;
728 
729  /// \brief Finalize function instrumentation.
730  ///
731  /// This method is called after visiting all interesting (see above)
732  /// instructions in a function.
733  virtual void finalizeInstrumentation() = 0;
734 };
735 
736 struct MemorySanitizerVisitor;
737 
738 } // end anonymous namespace
739 
740 static VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
741  MemorySanitizerVisitor &Visitor);
742 
743 static unsigned TypeSizeToSizeIndex(unsigned TypeSize) {
744  if (TypeSize <= 8) return 0;
745  return Log2_32_Ceil((TypeSize + 7) / 8);
746 }
747 
748 namespace {
749 
750 /// This class does all the work for a given function. Store and Load
751 /// instructions store and load corresponding shadow and origin
752 /// values. Most instructions propagate shadow from arguments to their
753 /// return values. Certain instructions (most importantly, BranchInst)
754 /// test their argument shadow and print reports (with a runtime call) if it's
755 /// non-zero.
756 struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
757  Function &F;
758  MemorySanitizer &MS;
759  SmallVector<PHINode *, 16> ShadowPHINodes, OriginPHINodes;
760  ValueMap<Value*, Value*> ShadowMap, OriginMap;
761  std::unique_ptr<VarArgHelper> VAHelper;
762  const TargetLibraryInfo *TLI;
763  BasicBlock *ActualFnStart;
764 
765  // The following flags disable parts of MSan instrumentation based on
766  // blacklist contents and command-line options.
767  bool InsertChecks;
768  bool PropagateShadow;
769  bool PoisonStack;
770  bool PoisonUndef;
771  bool CheckReturnValue;
772 
773  struct ShadowOriginAndInsertPoint {
774  Value *Shadow;
775  Value *Origin;
776  Instruction *OrigIns;
777 
778  ShadowOriginAndInsertPoint(Value *S, Value *O, Instruction *I)
779  : Shadow(S), Origin(O), OrigIns(I) {}
780  };
783 
784  MemorySanitizerVisitor(Function &F, MemorySanitizer &MS)
785  : F(F), MS(MS), VAHelper(CreateVarArgHelper(F, MS, *this)) {
786  bool SanitizeFunction = F.hasFnAttribute(Attribute::SanitizeMemory);
787  InsertChecks = SanitizeFunction;
788  PropagateShadow = SanitizeFunction;
789  PoisonStack = SanitizeFunction && ClPoisonStack;
790  PoisonUndef = SanitizeFunction && ClPoisonUndef;
791  // FIXME: Consider using SpecialCaseList to specify a list of functions that
792  // must always return fully initialized values. For now, we hardcode "main".
793  CheckReturnValue = SanitizeFunction && (F.getName() == "main");
794  TLI = &MS.getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
795 
796  MS.initializeCallbacks(*F.getParent());
797  ActualFnStart = &F.getEntryBlock();
798 
799  DEBUG(if (!InsertChecks)
800  dbgs() << "MemorySanitizer is not inserting checks into '"
801  << F.getName() << "'\n");
802  }
803 
804  Value *updateOrigin(Value *V, IRBuilder<> &IRB) {
805  if (MS.TrackOrigins <= 1) return V;
806  return IRB.CreateCall(MS.MsanChainOriginFn, V);
807  }
808 
809  Value *originToIntptr(IRBuilder<> &IRB, Value *Origin) {
810  const DataLayout &DL = F.getParent()->getDataLayout();
811  unsigned IntptrSize = DL.getTypeStoreSize(MS.IntptrTy);
812  if (IntptrSize == kOriginSize) return Origin;
813  assert(IntptrSize == kOriginSize * 2);
814  Origin = IRB.CreateIntCast(Origin, MS.IntptrTy, /* isSigned */ false);
815  return IRB.CreateOr(Origin, IRB.CreateShl(Origin, kOriginSize * 8));
816  }
817 
818  /// \brief Fill memory range with the given origin value.
819  void paintOrigin(IRBuilder<> &IRB, Value *Origin, Value *OriginPtr,
820  unsigned Size, unsigned Alignment) {
821  const DataLayout &DL = F.getParent()->getDataLayout();
822  unsigned IntptrAlignment = DL.getABITypeAlignment(MS.IntptrTy);
823  unsigned IntptrSize = DL.getTypeStoreSize(MS.IntptrTy);
824  assert(IntptrAlignment >= kMinOriginAlignment);
825  assert(IntptrSize >= kOriginSize);
826 
827  unsigned Ofs = 0;
828  unsigned CurrentAlignment = Alignment;
829  if (Alignment >= IntptrAlignment && IntptrSize > kOriginSize) {
830  Value *IntptrOrigin = originToIntptr(IRB, Origin);
831  Value *IntptrOriginPtr =
832  IRB.CreatePointerCast(OriginPtr, PointerType::get(MS.IntptrTy, 0));
833  for (unsigned i = 0; i < Size / IntptrSize; ++i) {
834  Value *Ptr = i ? IRB.CreateConstGEP1_32(MS.IntptrTy, IntptrOriginPtr, i)
835  : IntptrOriginPtr;
836  IRB.CreateAlignedStore(IntptrOrigin, Ptr, CurrentAlignment);
837  Ofs += IntptrSize / kOriginSize;
838  CurrentAlignment = IntptrAlignment;
839  }
840  }
841 
842  for (unsigned i = Ofs; i < (Size + kOriginSize - 1) / kOriginSize; ++i) {
843  Value *GEP =
844  i ? IRB.CreateConstGEP1_32(nullptr, OriginPtr, i) : OriginPtr;
845  IRB.CreateAlignedStore(Origin, GEP, CurrentAlignment);
846  CurrentAlignment = kMinOriginAlignment;
847  }
848  }
849 
850  void storeOrigin(IRBuilder<> &IRB, Value *Addr, Value *Shadow, Value *Origin,
851  Value *OriginPtr, unsigned Alignment, bool AsCall) {
852  const DataLayout &DL = F.getParent()->getDataLayout();
853  unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment);
854  unsigned StoreSize = DL.getTypeStoreSize(Shadow->getType());
855  if (Shadow->getType()->isAggregateType()) {
856  paintOrigin(IRB, updateOrigin(Origin, IRB), OriginPtr, StoreSize,
857  OriginAlignment);
858  } else {
859  Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
860  Constant *ConstantShadow = dyn_cast_or_null<Constant>(ConvertedShadow);
861  if (ConstantShadow) {
862  if (ClCheckConstantShadow && !ConstantShadow->isZeroValue())
863  paintOrigin(IRB, updateOrigin(Origin, IRB), OriginPtr, StoreSize,
864  OriginAlignment);
865  return;
866  }
867 
868  unsigned TypeSizeInBits =
869  DL.getTypeSizeInBits(ConvertedShadow->getType());
870  unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits);
871  if (AsCall && SizeIndex < kNumberOfAccessSizes) {
872  Value *Fn = MS.MaybeStoreOriginFn[SizeIndex];
873  Value *ConvertedShadow2 = IRB.CreateZExt(
874  ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
875  IRB.CreateCall(Fn, {ConvertedShadow2,
876  IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),
877  Origin});
878  } else {
879  Value *Cmp = IRB.CreateICmpNE(
880  ConvertedShadow, getCleanShadow(ConvertedShadow), "_mscmp");
882  Cmp, &*IRB.GetInsertPoint(), false, MS.OriginStoreWeights);
883  IRBuilder<> IRBNew(CheckTerm);
884  paintOrigin(IRBNew, updateOrigin(Origin, IRBNew), OriginPtr, StoreSize,
885  OriginAlignment);
886  }
887  }
888  }
889 
890  void materializeStores(bool InstrumentWithCalls) {
891  for (StoreInst *SI : StoreList) {
892  IRBuilder<> IRB(SI);
893  Value *Val = SI->getValueOperand();
894  Value *Addr = SI->getPointerOperand();
895  Value *Shadow = SI->isAtomic() ? getCleanShadow(Val) : getShadow(Val);
896  Value *ShadowPtr, *OriginPtr;
897  Type *ShadowTy = Shadow->getType();
898  unsigned Alignment = SI->getAlignment();
899  unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment);
900  std::tie(ShadowPtr, OriginPtr) =
901  getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ true);
902 
903  StoreInst *NewSI = IRB.CreateAlignedStore(Shadow, ShadowPtr, Alignment);
904  DEBUG(dbgs() << " STORE: " << *NewSI << "\n");
905 
907  insertShadowCheck(Addr, NewSI);
908 
909  if (SI->isAtomic())
910  SI->setOrdering(addReleaseOrdering(SI->getOrdering()));
911 
912  if (MS.TrackOrigins && !SI->isAtomic())
913  storeOrigin(IRB, Addr, Shadow, getOrigin(Val), OriginPtr,
914  OriginAlignment, InstrumentWithCalls);
915  }
916  }
917 
918  /// \brief Helper function to insert a warning at IRB's current insert point.
919  void insertWarningFn(IRBuilder<> &IRB, Value *Origin) {
920  if (!Origin)
921  Origin = (Value *)IRB.getInt32(0);
922  if (MS.TrackOrigins) {
923  IRB.CreateStore(Origin, MS.OriginTLS);
924  }
925  IRB.CreateCall(MS.WarningFn, {});
926  IRB.CreateCall(MS.EmptyAsm, {});
927  // FIXME: Insert UnreachableInst if !MS.Recover?
928  // This may invalidate some of the following checks and needs to be done
929  // at the very end.
930  }
931 
932  void materializeOneCheck(Instruction *OrigIns, Value *Shadow, Value *Origin,
933  bool AsCall) {
934  IRBuilder<> IRB(OrigIns);
935  DEBUG(dbgs() << " SHAD0 : " << *Shadow << "\n");
936  Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
937  DEBUG(dbgs() << " SHAD1 : " << *ConvertedShadow << "\n");
938 
939  Constant *ConstantShadow = dyn_cast_or_null<Constant>(ConvertedShadow);
940  if (ConstantShadow) {
941  if (ClCheckConstantShadow && !ConstantShadow->isZeroValue()) {
942  insertWarningFn(IRB, Origin);
943  }
944  return;
945  }
946 
947  const DataLayout &DL = OrigIns->getModule()->getDataLayout();
948 
949  unsigned TypeSizeInBits = DL.getTypeSizeInBits(ConvertedShadow->getType());
950  unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits);
951  if (AsCall && SizeIndex < kNumberOfAccessSizes) {
952  Value *Fn = MS.MaybeWarningFn[SizeIndex];
953  Value *ConvertedShadow2 =
954  IRB.CreateZExt(ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
955  IRB.CreateCall(Fn, {ConvertedShadow2, MS.TrackOrigins && Origin
956  ? Origin
957  : (Value *)IRB.getInt32(0)});
958  } else {
959  Value *Cmp = IRB.CreateICmpNE(ConvertedShadow,
960  getCleanShadow(ConvertedShadow), "_mscmp");
962  Cmp, OrigIns,
963  /* Unreachable */ !MS.Recover, MS.ColdCallWeights);
964 
965  IRB.SetInsertPoint(CheckTerm);
966  insertWarningFn(IRB, Origin);
967  DEBUG(dbgs() << " CHECK: " << *Cmp << "\n");
968  }
969  }
970 
971  void materializeChecks(bool InstrumentWithCalls) {
972  for (const auto &ShadowData : InstrumentationList) {
973  Instruction *OrigIns = ShadowData.OrigIns;
974  Value *Shadow = ShadowData.Shadow;
975  Value *Origin = ShadowData.Origin;
976  materializeOneCheck(OrigIns, Shadow, Origin, InstrumentWithCalls);
977  }
978  DEBUG(dbgs() << "DONE:\n" << F);
979  }
980 
981  /// \brief Add MemorySanitizer instrumentation to a function.
982  bool runOnFunction() {
983  // In the presence of unreachable blocks, we may see Phi nodes with
984  // incoming nodes from such blocks. Since InstVisitor skips unreachable
985  // blocks, such nodes will not have any shadow value associated with them.
986  // It's easier to remove unreachable blocks than deal with missing shadow.
988 
989  // Iterate all BBs in depth-first order and create shadow instructions
990  // for all instructions (where applicable).
991  // For PHI nodes we create dummy shadow PHIs which will be finalized later.
992  for (BasicBlock *BB : depth_first(ActualFnStart))
993  visit(*BB);
994 
995  // Finalize PHI nodes.
996  for (PHINode *PN : ShadowPHINodes) {
997  PHINode *PNS = cast<PHINode>(getShadow(PN));
998  PHINode *PNO = MS.TrackOrigins ? cast<PHINode>(getOrigin(PN)) : nullptr;
999  size_t NumValues = PN->getNumIncomingValues();
1000  for (size_t v = 0; v < NumValues; v++) {
1001  PNS->addIncoming(getShadow(PN, v), PN->getIncomingBlock(v));
1002  if (PNO) PNO->addIncoming(getOrigin(PN, v), PN->getIncomingBlock(v));
1003  }
1004  }
1005 
1006  VAHelper->finalizeInstrumentation();
1007 
1008  bool InstrumentWithCalls = ClInstrumentationWithCallThreshold >= 0 &&
1009  InstrumentationList.size() + StoreList.size() >
1011 
1012  // Delayed instrumentation of StoreInst.
1013  // This may add new checks to be inserted later.
1014  materializeStores(InstrumentWithCalls);
1015 
1016  // Insert shadow value checks.
1017  materializeChecks(InstrumentWithCalls);
1018 
1019  return true;
1020  }
1021 
1022  /// \brief Compute the shadow type that corresponds to a given Value.
1023  Type *getShadowTy(Value *V) {
1024  return getShadowTy(V->getType());
1025  }
1026 
1027  /// \brief Compute the shadow type that corresponds to a given Type.
1028  Type *getShadowTy(Type *OrigTy) {
1029  if (!OrigTy->isSized()) {
1030  return nullptr;
1031  }
1032  // For integer type, shadow is the same as the original type.
1033  // This may return weird-sized types like i1.
1034  if (IntegerType *IT = dyn_cast<IntegerType>(OrigTy))
1035  return IT;
1036  const DataLayout &DL = F.getParent()->getDataLayout();
1037  if (VectorType *VT = dyn_cast<VectorType>(OrigTy)) {
1038  uint32_t EltSize = DL.getTypeSizeInBits(VT->getElementType());
1039  return VectorType::get(IntegerType::get(*MS.C, EltSize),
1040  VT->getNumElements());
1041  }
1042  if (ArrayType *AT = dyn_cast<ArrayType>(OrigTy)) {
1043  return ArrayType::get(getShadowTy(AT->getElementType()),
1044  AT->getNumElements());
1045  }
1046  if (StructType *ST = dyn_cast<StructType>(OrigTy)) {
1047  SmallVector<Type*, 4> Elements;
1048  for (unsigned i = 0, n = ST->getNumElements(); i < n; i++)
1049  Elements.push_back(getShadowTy(ST->getElementType(i)));
1050  StructType *Res = StructType::get(*MS.C, Elements, ST->isPacked());
1051  DEBUG(dbgs() << "getShadowTy: " << *ST << " ===> " << *Res << "\n");
1052  return Res;
1053  }
1054  uint32_t TypeSize = DL.getTypeSizeInBits(OrigTy);
1055  return IntegerType::get(*MS.C, TypeSize);
1056  }
1057 
1058  /// \brief Flatten a vector type.
1059  Type *getShadowTyNoVec(Type *ty) {
1060  if (VectorType *vt = dyn_cast<VectorType>(ty))
1061  return IntegerType::get(*MS.C, vt->getBitWidth());
1062  return ty;
1063  }
1064 
1065  /// \brief Convert a shadow value to it's flattened variant.
1066  Value *convertToShadowTyNoVec(Value *V, IRBuilder<> &IRB) {
1067  Type *Ty = V->getType();
1068  Type *NoVecTy = getShadowTyNoVec(Ty);
1069  if (Ty == NoVecTy) return V;
1070  return IRB.CreateBitCast(V, NoVecTy);
1071  }
1072 
1073  /// \brief Compute the integer shadow offset that corresponds to a given
1074  /// application address.
1075  ///
1076  /// Offset = (Addr & ~AndMask) ^ XorMask
1077  Value *getShadowPtrOffset(Value *Addr, IRBuilder<> &IRB) {
1078  Value *OffsetLong = IRB.CreatePointerCast(Addr, MS.IntptrTy);
1079 
1080  uint64_t AndMask = MS.MapParams->AndMask;
1081  if (AndMask)
1082  OffsetLong =
1083  IRB.CreateAnd(OffsetLong, ConstantInt::get(MS.IntptrTy, ~AndMask));
1084 
1085  uint64_t XorMask = MS.MapParams->XorMask;
1086  if (XorMask)
1087  OffsetLong =
1088  IRB.CreateXor(OffsetLong, ConstantInt::get(MS.IntptrTy, XorMask));
1089  return OffsetLong;
1090  }
1091 
1092  /// \brief Compute the shadow and origin addresses corresponding to a given
1093  /// application address.
1094  ///
1095  /// Shadow = ShadowBase + Offset
1096  /// Origin = (OriginBase + Offset) & ~3ULL
1097  std::pair<Value *, Value *> getShadowOriginPtrUserspace(
1098  Value *Addr, IRBuilder<> &IRB, Type *ShadowTy, unsigned Alignment,
1099  Instruction **FirstInsn) {
1100  Value *ShadowOffset = getShadowPtrOffset(Addr, IRB);
1101  Value *ShadowLong = ShadowOffset;
1102  uint64_t ShadowBase = MS.MapParams->ShadowBase;
1103  *FirstInsn = dyn_cast<Instruction>(ShadowLong);
1104  if (ShadowBase != 0) {
1105  ShadowLong =
1106  IRB.CreateAdd(ShadowLong,
1107  ConstantInt::get(MS.IntptrTy, ShadowBase));
1108  }
1109  Value *ShadowPtr =
1110  IRB.CreateIntToPtr(ShadowLong, PointerType::get(ShadowTy, 0));
1111  Value *OriginPtr = nullptr;
1112  if (MS.TrackOrigins) {
1113  Value *OriginLong = ShadowOffset;
1114  uint64_t OriginBase = MS.MapParams->OriginBase;
1115  if (OriginBase != 0)
1116  OriginLong = IRB.CreateAdd(OriginLong,
1117  ConstantInt::get(MS.IntptrTy, OriginBase));
1118  if (Alignment < kMinOriginAlignment) {
1119  uint64_t Mask = kMinOriginAlignment - 1;
1120  OriginLong =
1121  IRB.CreateAnd(OriginLong, ConstantInt::get(MS.IntptrTy, ~Mask));
1122  }
1123  OriginPtr =
1124  IRB.CreateIntToPtr(OriginLong, PointerType::get(IRB.getInt32Ty(), 0));
1125  }
1126  return std::make_pair(ShadowPtr, OriginPtr);
1127  }
1128 
1129  std::pair<Value *, Value *> getShadowOriginPtr(Value *Addr, IRBuilder<> &IRB,
1130  Type *ShadowTy,
1131  unsigned Alignment,
1132  bool isStore) {
1133  Instruction *FirstInsn = nullptr;
1134  std::pair<Value *, Value *> ret =
1135  getShadowOriginPtrUserspace(Addr, IRB, ShadowTy, Alignment, &FirstInsn);
1136  return ret;
1137  }
1138 
1139  /// \brief Compute the shadow address for a given function argument.
1140  ///
1141  /// Shadow = ParamTLS+ArgOffset.
1142  Value *getShadowPtrForArgument(Value *A, IRBuilder<> &IRB,
1143  int ArgOffset) {
1144  Value *Base = IRB.CreatePointerCast(MS.ParamTLS, MS.IntptrTy);
1145  if (ArgOffset)
1146  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
1147  return IRB.CreateIntToPtr(Base, PointerType::get(getShadowTy(A), 0),
1148  "_msarg");
1149  }
1150 
1151  /// \brief Compute the origin address for a given function argument.
1152  Value *getOriginPtrForArgument(Value *A, IRBuilder<> &IRB,
1153  int ArgOffset) {
1154  if (!MS.TrackOrigins) return nullptr;
1155  Value *Base = IRB.CreatePointerCast(MS.ParamOriginTLS, MS.IntptrTy);
1156  if (ArgOffset)
1157  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
1158  return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0),
1159  "_msarg_o");
1160  }
1161 
1162  /// \brief Compute the shadow address for a retval.
1163  Value *getShadowPtrForRetval(Value *A, IRBuilder<> &IRB) {
1164  return IRB.CreatePointerCast(MS.RetvalTLS,
1165  PointerType::get(getShadowTy(A), 0),
1166  "_msret");
1167  }
1168 
1169  /// \brief Compute the origin address for a retval.
1170  Value *getOriginPtrForRetval(IRBuilder<> &IRB) {
1171  // We keep a single origin for the entire retval. Might be too optimistic.
1172  return MS.RetvalOriginTLS;
1173  }
1174 
1175  /// \brief Set SV to be the shadow value for V.
1176  void setShadow(Value *V, Value *SV) {
1177  assert(!ShadowMap.count(V) && "Values may only have one shadow");
1178  ShadowMap[V] = PropagateShadow ? SV : getCleanShadow(V);
1179  }
1180 
1181  /// \brief Set Origin to be the origin value for V.
1182  void setOrigin(Value *V, Value *Origin) {
1183  if (!MS.TrackOrigins) return;
1184  assert(!OriginMap.count(V) && "Values may only have one origin");
1185  DEBUG(dbgs() << "ORIGIN: " << *V << " ==> " << *Origin << "\n");
1186  OriginMap[V] = Origin;
1187  }
1188 
1189  Constant *getCleanShadow(Type *OrigTy) {
1190  Type *ShadowTy = getShadowTy(OrigTy);
1191  if (!ShadowTy)
1192  return nullptr;
1193  return Constant::getNullValue(ShadowTy);
1194  }
1195 
1196  /// \brief Create a clean shadow value for a given value.
1197  ///
1198  /// Clean shadow (all zeroes) means all bits of the value are defined
1199  /// (initialized).
1200  Constant *getCleanShadow(Value *V) {
1201  return getCleanShadow(V->getType());
1202  }
1203 
1204  /// \brief Create a dirty shadow of a given shadow type.
1205  Constant *getPoisonedShadow(Type *ShadowTy) {
1206  assert(ShadowTy);
1207  if (isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy))
1208  return Constant::getAllOnesValue(ShadowTy);
1209  if (ArrayType *AT = dyn_cast<ArrayType>(ShadowTy)) {
1210  SmallVector<Constant *, 4> Vals(AT->getNumElements(),
1211  getPoisonedShadow(AT->getElementType()));
1212  return ConstantArray::get(AT, Vals);
1213  }
1214  if (StructType *ST = dyn_cast<StructType>(ShadowTy)) {
1216  for (unsigned i = 0, n = ST->getNumElements(); i < n; i++)
1217  Vals.push_back(getPoisonedShadow(ST->getElementType(i)));
1218  return ConstantStruct::get(ST, Vals);
1219  }
1220  llvm_unreachable("Unexpected shadow type");
1221  }
1222 
1223  /// \brief Create a dirty shadow for a given value.
1224  Constant *getPoisonedShadow(Value *V) {
1225  Type *ShadowTy = getShadowTy(V);
1226  if (!ShadowTy)
1227  return nullptr;
1228  return getPoisonedShadow(ShadowTy);
1229  }
1230 
1231  /// \brief Create a clean (zero) origin.
1232  Value *getCleanOrigin() {
1233  return Constant::getNullValue(MS.OriginTy);
1234  }
1235 
1236  /// \brief Get the shadow value for a given Value.
1237  ///
1238  /// This function either returns the value set earlier with setShadow,
1239  /// or extracts if from ParamTLS (for function arguments).
1240  Value *getShadow(Value *V) {
1241  if (!PropagateShadow) return getCleanShadow(V);
1242  if (Instruction *I = dyn_cast<Instruction>(V)) {
1243  if (I->getMetadata("nosanitize"))
1244  return getCleanShadow(V);
1245  // For instructions the shadow is already stored in the map.
1246  Value *Shadow = ShadowMap[V];
1247  if (!Shadow) {
1248  DEBUG(dbgs() << "No shadow: " << *V << "\n" << *(I->getParent()));
1249  (void)I;
1250  assert(Shadow && "No shadow for a value");
1251  }
1252  return Shadow;
1253  }
1254  if (UndefValue *U = dyn_cast<UndefValue>(V)) {
1255  Value *AllOnes = PoisonUndef ? getPoisonedShadow(V) : getCleanShadow(V);
1256  DEBUG(dbgs() << "Undef: " << *U << " ==> " << *AllOnes << "\n");
1257  (void)U;
1258  return AllOnes;
1259  }
1260  if (Argument *A = dyn_cast<Argument>(V)) {
1261  // For arguments we compute the shadow on demand and store it in the map.
1262  Value **ShadowPtr = &ShadowMap[V];
1263  if (*ShadowPtr)
1264  return *ShadowPtr;
1265  Function *F = A->getParent();
1266  IRBuilder<> EntryIRB(ActualFnStart->getFirstNonPHI());
1267  unsigned ArgOffset = 0;
1268  const DataLayout &DL = F->getParent()->getDataLayout();
1269  for (auto &FArg : F->args()) {
1270  if (!FArg.getType()->isSized()) {
1271  DEBUG(dbgs() << "Arg is not sized\n");
1272  continue;
1273  }
1274  unsigned Size =
1275  FArg.hasByValAttr()
1276  ? DL.getTypeAllocSize(FArg.getType()->getPointerElementType())
1277  : DL.getTypeAllocSize(FArg.getType());
1278  if (A == &FArg) {
1279  bool Overflow = ArgOffset + Size > kParamTLSSize;
1280  Value *Base = getShadowPtrForArgument(&FArg, EntryIRB, ArgOffset);
1281  if (FArg.hasByValAttr()) {
1282  // ByVal pointer itself has clean shadow. We copy the actual
1283  // argument shadow to the underlying memory.
1284  // Figure out maximal valid memcpy alignment.
1285  unsigned ArgAlign = FArg.getParamAlignment();
1286  if (ArgAlign == 0) {
1287  Type *EltType = A->getType()->getPointerElementType();
1288  ArgAlign = DL.getABITypeAlignment(EltType);
1289  }
1290  Value *CpShadowPtr =
1291  getShadowOriginPtr(V, EntryIRB, EntryIRB.getInt8Ty(), ArgAlign,
1292  /*isStore*/ true)
1293  .first;
1294  if (Overflow) {
1295  // ParamTLS overflow.
1296  EntryIRB.CreateMemSet(
1297  CpShadowPtr, Constant::getNullValue(EntryIRB.getInt8Ty()),
1298  Size, ArgAlign);
1299  } else {
1300  unsigned CopyAlign = std::min(ArgAlign, kShadowTLSAlignment);
1301  Value *Cpy = EntryIRB.CreateMemCpy(CpShadowPtr, CopyAlign, Base,
1302  CopyAlign, Size);
1303  DEBUG(dbgs() << " ByValCpy: " << *Cpy << "\n");
1304  (void)Cpy;
1305  }
1306  *ShadowPtr = getCleanShadow(V);
1307  } else {
1308  if (Overflow) {
1309  // ParamTLS overflow.
1310  *ShadowPtr = getCleanShadow(V);
1311  } else {
1312  *ShadowPtr =
1313  EntryIRB.CreateAlignedLoad(Base, kShadowTLSAlignment);
1314  }
1315  }
1316  DEBUG(dbgs() << " ARG: " << FArg << " ==> " <<
1317  **ShadowPtr << "\n");
1318  if (MS.TrackOrigins && !Overflow) {
1319  Value *OriginPtr =
1320  getOriginPtrForArgument(&FArg, EntryIRB, ArgOffset);
1321  setOrigin(A, EntryIRB.CreateLoad(OriginPtr));
1322  } else {
1323  setOrigin(A, getCleanOrigin());
1324  }
1325  }
1326  ArgOffset += alignTo(Size, kShadowTLSAlignment);
1327  }
1328  assert(*ShadowPtr && "Could not find shadow for an argument");
1329  return *ShadowPtr;
1330  }
1331  // For everything else the shadow is zero.
1332  return getCleanShadow(V);
1333  }
1334 
1335  /// \brief Get the shadow for i-th argument of the instruction I.
1336  Value *getShadow(Instruction *I, int i) {
1337  return getShadow(I->getOperand(i));
1338  }
1339 
1340  /// \brief Get the origin for a value.
1341  Value *getOrigin(Value *V) {
1342  if (!MS.TrackOrigins) return nullptr;
1343  if (!PropagateShadow) return getCleanOrigin();
1344  if (isa<Constant>(V)) return getCleanOrigin();
1345  assert((isa<Instruction>(V) || isa<Argument>(V)) &&
1346  "Unexpected value type in getOrigin()");
1347  if (Instruction *I = dyn_cast<Instruction>(V)) {
1348  if (I->getMetadata("nosanitize"))
1349  return getCleanOrigin();
1350  }
1351  Value *Origin = OriginMap[V];
1352  assert(Origin && "Missing origin");
1353  return Origin;
1354  }
1355 
1356  /// \brief Get the origin for i-th argument of the instruction I.
1357  Value *getOrigin(Instruction *I, int i) {
1358  return getOrigin(I->getOperand(i));
1359  }
1360 
1361  /// \brief Remember the place where a shadow check should be inserted.
1362  ///
1363  /// This location will be later instrumented with a check that will print a
1364  /// UMR warning in runtime if the shadow value is not 0.
1365  void insertShadowCheck(Value *Shadow, Value *Origin, Instruction *OrigIns) {
1366  assert(Shadow);
1367  if (!InsertChecks) return;
1368 #ifndef NDEBUG
1369  Type *ShadowTy = Shadow->getType();
1370  assert((isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) &&
1371  "Can only insert checks for integer and vector shadow types");
1372 #endif
1373  InstrumentationList.push_back(
1374  ShadowOriginAndInsertPoint(Shadow, Origin, OrigIns));
1375  }
1376 
1377  /// \brief Remember the place where a shadow check should be inserted.
1378  ///
1379  /// This location will be later instrumented with a check that will print a
1380  /// UMR warning in runtime if the value is not fully defined.
1381  void insertShadowCheck(Value *Val, Instruction *OrigIns) {
1382  assert(Val);
1383  Value *Shadow, *Origin;
1384  if (ClCheckConstantShadow) {
1385  Shadow = getShadow(Val);
1386  if (!Shadow) return;
1387  Origin = getOrigin(Val);
1388  } else {
1389  Shadow = dyn_cast_or_null<Instruction>(getShadow(Val));
1390  if (!Shadow) return;
1391  Origin = dyn_cast_or_null<Instruction>(getOrigin(Val));
1392  }
1393  insertShadowCheck(Shadow, Origin, OrigIns);
1394  }
1395 
1396  AtomicOrdering addReleaseOrdering(AtomicOrdering a) {
1397  switch (a) {
1403  return AtomicOrdering::Release;
1409  }
1410  llvm_unreachable("Unknown ordering");
1411  }
1412 
1413  AtomicOrdering addAcquireOrdering(AtomicOrdering a) {
1414  switch (a) {
1420  return AtomicOrdering::Acquire;
1426  }
1427  llvm_unreachable("Unknown ordering");
1428  }
1429 
1430  // ------------------- Visitors.
1432  void visit(Instruction &I) {
1433  if (!I.getMetadata("nosanitize"))
1435  }
1436 
1437  /// \brief Instrument LoadInst
1438  ///
1439  /// Loads the corresponding shadow and (optionally) origin.
1440  /// Optionally, checks that the load address is fully defined.
1441  void visitLoadInst(LoadInst &I) {
1442  assert(I.getType()->isSized() && "Load type must have size");
1443  assert(!I.getMetadata("nosanitize"));
1444  IRBuilder<> IRB(I.getNextNode());
1445  Type *ShadowTy = getShadowTy(&I);
1446  Value *Addr = I.getPointerOperand();
1447  Value *ShadowPtr, *OriginPtr;
1448  unsigned Alignment = I.getAlignment();
1449  if (PropagateShadow) {
1450  std::tie(ShadowPtr, OriginPtr) =
1451  getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false);
1452  setShadow(&I, IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_msld"));
1453  } else {
1454  setShadow(&I, getCleanShadow(&I));
1455  }
1456 
1458  insertShadowCheck(I.getPointerOperand(), &I);
1459 
1460  if (I.isAtomic())
1461  I.setOrdering(addAcquireOrdering(I.getOrdering()));
1462 
1463  if (MS.TrackOrigins) {
1464  if (PropagateShadow) {
1465  unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment);
1466  setOrigin(&I, IRB.CreateAlignedLoad(OriginPtr, OriginAlignment));
1467  } else {
1468  setOrigin(&I, getCleanOrigin());
1469  }
1470  }
1471  }
1472 
1473  /// \brief Instrument StoreInst
1474  ///
1475  /// Stores the corresponding shadow and (optionally) origin.
1476  /// Optionally, checks that the store address is fully defined.
1477  void visitStoreInst(StoreInst &I) {
1478  StoreList.push_back(&I);
1479  }
1480 
1481  void handleCASOrRMW(Instruction &I) {
1482  assert(isa<AtomicRMWInst>(I) || isa<AtomicCmpXchgInst>(I));
1483 
1484  IRBuilder<> IRB(&I);
1485  Value *Addr = I.getOperand(0);
1486  Value *ShadowPtr = getShadowOriginPtr(Addr, IRB, I.getType(),
1487  /*Alignment*/ 1, /*isStore*/ true)
1488  .first;
1489 
1491  insertShadowCheck(Addr, &I);
1492 
1493  // Only test the conditional argument of cmpxchg instruction.
1494  // The other argument can potentially be uninitialized, but we can not
1495  // detect this situation reliably without possible false positives.
1496  if (isa<AtomicCmpXchgInst>(I))
1497  insertShadowCheck(I.getOperand(1), &I);
1498 
1499  IRB.CreateStore(getCleanShadow(&I), ShadowPtr);
1500 
1501  setShadow(&I, getCleanShadow(&I));
1502  setOrigin(&I, getCleanOrigin());
1503  }
1504 
1505  void visitAtomicRMWInst(AtomicRMWInst &I) {
1506  handleCASOrRMW(I);
1507  I.setOrdering(addReleaseOrdering(I.getOrdering()));
1508  }
1509 
1510  void visitAtomicCmpXchgInst(AtomicCmpXchgInst &I) {
1511  handleCASOrRMW(I);
1512  I.setSuccessOrdering(addReleaseOrdering(I.getSuccessOrdering()));
1513  }
1514 
1515  // Vector manipulation.
1516  void visitExtractElementInst(ExtractElementInst &I) {
1517  insertShadowCheck(I.getOperand(1), &I);
1518  IRBuilder<> IRB(&I);
1519  setShadow(&I, IRB.CreateExtractElement(getShadow(&I, 0), I.getOperand(1),
1520  "_msprop"));
1521  setOrigin(&I, getOrigin(&I, 0));
1522  }
1523 
1524  void visitInsertElementInst(InsertElementInst &I) {
1525  insertShadowCheck(I.getOperand(2), &I);
1526  IRBuilder<> IRB(&I);
1527  setShadow(&I, IRB.CreateInsertElement(getShadow(&I, 0), getShadow(&I, 1),
1528  I.getOperand(2), "_msprop"));
1529  setOriginForNaryOp(I);
1530  }
1531 
1532  void visitShuffleVectorInst(ShuffleVectorInst &I) {
1533  insertShadowCheck(I.getOperand(2), &I);
1534  IRBuilder<> IRB(&I);
1535  setShadow(&I, IRB.CreateShuffleVector(getShadow(&I, 0), getShadow(&I, 1),
1536  I.getOperand(2), "_msprop"));
1537  setOriginForNaryOp(I);
1538  }
1539 
1540  // Casts.
1541  void visitSExtInst(SExtInst &I) {
1542  IRBuilder<> IRB(&I);
1543  setShadow(&I, IRB.CreateSExt(getShadow(&I, 0), I.getType(), "_msprop"));
1544  setOrigin(&I, getOrigin(&I, 0));
1545  }
1546 
1547  void visitZExtInst(ZExtInst &I) {
1548  IRBuilder<> IRB(&I);
1549  setShadow(&I, IRB.CreateZExt(getShadow(&I, 0), I.getType(), "_msprop"));
1550  setOrigin(&I, getOrigin(&I, 0));
1551  }
1552 
1553  void visitTruncInst(TruncInst &I) {
1554  IRBuilder<> IRB(&I);
1555  setShadow(&I, IRB.CreateTrunc(getShadow(&I, 0), I.getType(), "_msprop"));
1556  setOrigin(&I, getOrigin(&I, 0));
1557  }
1558 
1559  void visitBitCastInst(BitCastInst &I) {
1560  // Special case: if this is the bitcast (there is exactly 1 allowed) between
1561  // a musttail call and a ret, don't instrument. New instructions are not
1562  // allowed after a musttail call.
1563  if (auto *CI = dyn_cast<CallInst>(I.getOperand(0)))
1564  if (CI->isMustTailCall())
1565  return;
1566  IRBuilder<> IRB(&I);
1567  setShadow(&I, IRB.CreateBitCast(getShadow(&I, 0), getShadowTy(&I)));
1568  setOrigin(&I, getOrigin(&I, 0));
1569  }
1570 
1571  void visitPtrToIntInst(PtrToIntInst &I) {
1572  IRBuilder<> IRB(&I);
1573  setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false,
1574  "_msprop_ptrtoint"));
1575  setOrigin(&I, getOrigin(&I, 0));
1576  }
1577 
1578  void visitIntToPtrInst(IntToPtrInst &I) {
1579  IRBuilder<> IRB(&I);
1580  setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false,
1581  "_msprop_inttoptr"));
1582  setOrigin(&I, getOrigin(&I, 0));
1583  }
1584 
1585  void visitFPToSIInst(CastInst& I) { handleShadowOr(I); }
1586  void visitFPToUIInst(CastInst& I) { handleShadowOr(I); }
1587  void visitSIToFPInst(CastInst& I) { handleShadowOr(I); }
1588  void visitUIToFPInst(CastInst& I) { handleShadowOr(I); }
1589  void visitFPExtInst(CastInst& I) { handleShadowOr(I); }
1590  void visitFPTruncInst(CastInst& I) { handleShadowOr(I); }
1591 
1592  /// \brief Propagate shadow for bitwise AND.
1593  ///
1594  /// This code is exact, i.e. if, for example, a bit in the left argument
1595  /// is defined and 0, then neither the value not definedness of the
1596  /// corresponding bit in B don't affect the resulting shadow.
1597  void visitAnd(BinaryOperator &I) {
1598  IRBuilder<> IRB(&I);
1599  // "And" of 0 and a poisoned value results in unpoisoned value.
1600  // 1&1 => 1; 0&1 => 0; p&1 => p;
1601  // 1&0 => 0; 0&0 => 0; p&0 => 0;
1602  // 1&p => p; 0&p => 0; p&p => p;
1603  // S = (S1 & S2) | (V1 & S2) | (S1 & V2)
1604  Value *S1 = getShadow(&I, 0);
1605  Value *S2 = getShadow(&I, 1);
1606  Value *V1 = I.getOperand(0);
1607  Value *V2 = I.getOperand(1);
1608  if (V1->getType() != S1->getType()) {
1609  V1 = IRB.CreateIntCast(V1, S1->getType(), false);
1610  V2 = IRB.CreateIntCast(V2, S2->getType(), false);
1611  }
1612  Value *S1S2 = IRB.CreateAnd(S1, S2);
1613  Value *V1S2 = IRB.CreateAnd(V1, S2);
1614  Value *S1V2 = IRB.CreateAnd(S1, V2);
1615  setShadow(&I, IRB.CreateOr(S1S2, IRB.CreateOr(V1S2, S1V2)));
1616  setOriginForNaryOp(I);
1617  }
1618 
1619  void visitOr(BinaryOperator &I) {
1620  IRBuilder<> IRB(&I);
1621  // "Or" of 1 and a poisoned value results in unpoisoned value.
1622  // 1|1 => 1; 0|1 => 1; p|1 => 1;
1623  // 1|0 => 1; 0|0 => 0; p|0 => p;
1624  // 1|p => 1; 0|p => p; p|p => p;
1625  // S = (S1 & S2) | (~V1 & S2) | (S1 & ~V2)
1626  Value *S1 = getShadow(&I, 0);
1627  Value *S2 = getShadow(&I, 1);
1628  Value *V1 = IRB.CreateNot(I.getOperand(0));
1629  Value *V2 = IRB.CreateNot(I.getOperand(1));
1630  if (V1->getType() != S1->getType()) {
1631  V1 = IRB.CreateIntCast(V1, S1->getType(), false);
1632  V2 = IRB.CreateIntCast(V2, S2->getType(), false);
1633  }
1634  Value *S1S2 = IRB.CreateAnd(S1, S2);
1635  Value *V1S2 = IRB.CreateAnd(V1, S2);
1636  Value *S1V2 = IRB.CreateAnd(S1, V2);
1637  setShadow(&I, IRB.CreateOr(S1S2, IRB.CreateOr(V1S2, S1V2)));
1638  setOriginForNaryOp(I);
1639  }
1640 
1641  /// \brief Default propagation of shadow and/or origin.
1642  ///
1643  /// This class implements the general case of shadow propagation, used in all
1644  /// cases where we don't know and/or don't care about what the operation
1645  /// actually does. It converts all input shadow values to a common type
1646  /// (extending or truncating as necessary), and bitwise OR's them.
1647  ///
1648  /// This is much cheaper than inserting checks (i.e. requiring inputs to be
1649  /// fully initialized), and less prone to false positives.
1650  ///
1651  /// This class also implements the general case of origin propagation. For a
1652  /// Nary operation, result origin is set to the origin of an argument that is
1653  /// not entirely initialized. If there is more than one such arguments, the
1654  /// rightmost of them is picked. It does not matter which one is picked if all
1655  /// arguments are initialized.
1656  template <bool CombineShadow>
1657  class Combiner {
1658  Value *Shadow = nullptr;
1659  Value *Origin = nullptr;
1660  IRBuilder<> &IRB;
1661  MemorySanitizerVisitor *MSV;
1662 
1663  public:
1664  Combiner(MemorySanitizerVisitor *MSV, IRBuilder<> &IRB)
1665  : IRB(IRB), MSV(MSV) {}
1666 
1667  /// \brief Add a pair of shadow and origin values to the mix.
1668  Combiner &Add(Value *OpShadow, Value *OpOrigin) {
1669  if (CombineShadow) {
1670  assert(OpShadow);
1671  if (!Shadow)
1672  Shadow = OpShadow;
1673  else {
1674  OpShadow = MSV->CreateShadowCast(IRB, OpShadow, Shadow->getType());
1675  Shadow = IRB.CreateOr(Shadow, OpShadow, "_msprop");
1676  }
1677  }
1678 
1679  if (MSV->MS.TrackOrigins) {
1680  assert(OpOrigin);
1681  if (!Origin) {
1682  Origin = OpOrigin;
1683  } else {
1684  Constant *ConstOrigin = dyn_cast<Constant>(OpOrigin);
1685  // No point in adding something that might result in 0 origin value.
1686  if (!ConstOrigin || !ConstOrigin->isNullValue()) {
1687  Value *FlatShadow = MSV->convertToShadowTyNoVec(OpShadow, IRB);
1688  Value *Cond =
1689  IRB.CreateICmpNE(FlatShadow, MSV->getCleanShadow(FlatShadow));
1690  Origin = IRB.CreateSelect(Cond, OpOrigin, Origin);
1691  }
1692  }
1693  }
1694  return *this;
1695  }
1696 
1697  /// \brief Add an application value to the mix.
1698  Combiner &Add(Value *V) {
1699  Value *OpShadow = MSV->getShadow(V);
1700  Value *OpOrigin = MSV->MS.TrackOrigins ? MSV->getOrigin(V) : nullptr;
1701  return Add(OpShadow, OpOrigin);
1702  }
1703 
1704  /// \brief Set the current combined values as the given instruction's shadow
1705  /// and origin.
1706  void Done(Instruction *I) {
1707  if (CombineShadow) {
1708  assert(Shadow);
1709  Shadow = MSV->CreateShadowCast(IRB, Shadow, MSV->getShadowTy(I));
1710  MSV->setShadow(I, Shadow);
1711  }
1712  if (MSV->MS.TrackOrigins) {
1713  assert(Origin);
1714  MSV->setOrigin(I, Origin);
1715  }
1716  }
1717  };
1718 
1719  using ShadowAndOriginCombiner = Combiner<true>;
1720  using OriginCombiner = Combiner<false>;
1721 
1722  /// \brief Propagate origin for arbitrary operation.
1723  void setOriginForNaryOp(Instruction &I) {
1724  if (!MS.TrackOrigins) return;
1725  IRBuilder<> IRB(&I);
1726  OriginCombiner OC(this, IRB);
1727  for (Instruction::op_iterator OI = I.op_begin(); OI != I.op_end(); ++OI)
1728  OC.Add(OI->get());
1729  OC.Done(&I);
1730  }
1731 
1732  size_t VectorOrPrimitiveTypeSizeInBits(Type *Ty) {
1733  assert(!(Ty->isVectorTy() && Ty->getScalarType()->isPointerTy()) &&
1734  "Vector of pointers is not a valid shadow type");
1735  return Ty->isVectorTy() ?
1737  Ty->getPrimitiveSizeInBits();
1738  }
1739 
1740  /// \brief Cast between two shadow types, extending or truncating as
1741  /// necessary.
1742  Value *CreateShadowCast(IRBuilder<> &IRB, Value *V, Type *dstTy,
1743  bool Signed = false) {
1744  Type *srcTy = V->getType();
1745  size_t srcSizeInBits = VectorOrPrimitiveTypeSizeInBits(srcTy);
1746  size_t dstSizeInBits = VectorOrPrimitiveTypeSizeInBits(dstTy);
1747  if (srcSizeInBits > 1 && dstSizeInBits == 1)
1748  return IRB.CreateICmpNE(V, getCleanShadow(V));
1749 
1750  if (dstTy->isIntegerTy() && srcTy->isIntegerTy())
1751  return IRB.CreateIntCast(V, dstTy, Signed);
1752  if (dstTy->isVectorTy() && srcTy->isVectorTy() &&
1753  dstTy->getVectorNumElements() == srcTy->getVectorNumElements())
1754  return IRB.CreateIntCast(V, dstTy, Signed);
1755  Value *V1 = IRB.CreateBitCast(V, Type::getIntNTy(*MS.C, srcSizeInBits));
1756  Value *V2 =
1757  IRB.CreateIntCast(V1, Type::getIntNTy(*MS.C, dstSizeInBits), Signed);
1758  return IRB.CreateBitCast(V2, dstTy);
1759  // TODO: handle struct types.
1760  }
1761 
1762  /// \brief Cast an application value to the type of its own shadow.
1763  Value *CreateAppToShadowCast(IRBuilder<> &IRB, Value *V) {
1764  Type *ShadowTy = getShadowTy(V);
1765  if (V->getType() == ShadowTy)
1766  return V;
1767  if (V->getType()->isPtrOrPtrVectorTy())
1768  return IRB.CreatePtrToInt(V, ShadowTy);
1769  else
1770  return IRB.CreateBitCast(V, ShadowTy);
1771  }
1772 
1773  /// \brief Propagate shadow for arbitrary operation.
1774  void handleShadowOr(Instruction &I) {
1775  IRBuilder<> IRB(&I);
1776  ShadowAndOriginCombiner SC(this, IRB);
1777  for (Instruction::op_iterator OI = I.op_begin(); OI != I.op_end(); ++OI)
1778  SC.Add(OI->get());
1779  SC.Done(&I);
1780  }
1781 
1782  // \brief Handle multiplication by constant.
1783  //
1784  // Handle a special case of multiplication by constant that may have one or
1785  // more zeros in the lower bits. This makes corresponding number of lower bits
1786  // of the result zero as well. We model it by shifting the other operand
1787  // shadow left by the required number of bits. Effectively, we transform
1788  // (X * (A * 2**B)) to ((X << B) * A) and instrument (X << B) as (Sx << B).
1789  // We use multiplication by 2**N instead of shift to cover the case of
1790  // multiplication by 0, which may occur in some elements of a vector operand.
1791  void handleMulByConstant(BinaryOperator &I, Constant *ConstArg,
1792  Value *OtherArg) {
1793  Constant *ShadowMul;
1794  Type *Ty = ConstArg->getType();
1795  if (Ty->isVectorTy()) {
1796  unsigned NumElements = Ty->getVectorNumElements();
1797  Type *EltTy = Ty->getSequentialElementType();
1798  SmallVector<Constant *, 16> Elements;
1799  for (unsigned Idx = 0; Idx < NumElements; ++Idx) {
1800  if (ConstantInt *Elt =
1801  dyn_cast<ConstantInt>(ConstArg->getAggregateElement(Idx))) {
1802  const APInt &V = Elt->getValue();
1803  APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
1804  Elements.push_back(ConstantInt::get(EltTy, V2));
1805  } else {
1806  Elements.push_back(ConstantInt::get(EltTy, 1));
1807  }
1808  }
1809  ShadowMul = ConstantVector::get(Elements);
1810  } else {
1811  if (ConstantInt *Elt = dyn_cast<ConstantInt>(ConstArg)) {
1812  const APInt &V = Elt->getValue();
1813  APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
1814  ShadowMul = ConstantInt::get(Ty, V2);
1815  } else {
1816  ShadowMul = ConstantInt::get(Ty, 1);
1817  }
1818  }
1819 
1820  IRBuilder<> IRB(&I);
1821  setShadow(&I,
1822  IRB.CreateMul(getShadow(OtherArg), ShadowMul, "msprop_mul_cst"));
1823  setOrigin(&I, getOrigin(OtherArg));
1824  }
1825 
1826  void visitMul(BinaryOperator &I) {
1827  Constant *constOp0 = dyn_cast<Constant>(I.getOperand(0));
1828  Constant *constOp1 = dyn_cast<Constant>(I.getOperand(1));
1829  if (constOp0 && !constOp1)
1830  handleMulByConstant(I, constOp0, I.getOperand(1));
1831  else if (constOp1 && !constOp0)
1832  handleMulByConstant(I, constOp1, I.getOperand(0));
1833  else
1834  handleShadowOr(I);
1835  }
1836 
1837  void visitFAdd(BinaryOperator &I) { handleShadowOr(I); }
1838  void visitFSub(BinaryOperator &I) { handleShadowOr(I); }
1839  void visitFMul(BinaryOperator &I) { handleShadowOr(I); }
1840  void visitAdd(BinaryOperator &I) { handleShadowOr(I); }
1841  void visitSub(BinaryOperator &I) { handleShadowOr(I); }
1842  void visitXor(BinaryOperator &I) { handleShadowOr(I); }
1843 
1844  void handleDiv(Instruction &I) {
1845  IRBuilder<> IRB(&I);
1846  // Strict on the second argument.
1847  insertShadowCheck(I.getOperand(1), &I);
1848  setShadow(&I, getShadow(&I, 0));
1849  setOrigin(&I, getOrigin(&I, 0));
1850  }
1851 
1852  void visitUDiv(BinaryOperator &I) { handleDiv(I); }
1853  void visitSDiv(BinaryOperator &I) { handleDiv(I); }
1854  void visitFDiv(BinaryOperator &I) { handleDiv(I); }
1855  void visitURem(BinaryOperator &I) { handleDiv(I); }
1856  void visitSRem(BinaryOperator &I) { handleDiv(I); }
1857  void visitFRem(BinaryOperator &I) { handleDiv(I); }
1858 
1859  /// \brief Instrument == and != comparisons.
1860  ///
1861  /// Sometimes the comparison result is known even if some of the bits of the
1862  /// arguments are not.
1863  void handleEqualityComparison(ICmpInst &I) {
1864  IRBuilder<> IRB(&I);
1865  Value *A = I.getOperand(0);
1866  Value *B = I.getOperand(1);
1867  Value *Sa = getShadow(A);
1868  Value *Sb = getShadow(B);
1869 
1870  // Get rid of pointers and vectors of pointers.
1871  // For ints (and vectors of ints), types of A and Sa match,
1872  // and this is a no-op.
1873  A = IRB.CreatePointerCast(A, Sa->getType());
1874  B = IRB.CreatePointerCast(B, Sb->getType());
1875 
1876  // A == B <==> (C = A^B) == 0
1877  // A != B <==> (C = A^B) != 0
1878  // Sc = Sa | Sb
1879  Value *C = IRB.CreateXor(A, B);
1880  Value *Sc = IRB.CreateOr(Sa, Sb);
1881  // Now dealing with i = (C == 0) comparison (or C != 0, does not matter now)
1882  // Result is defined if one of the following is true
1883  // * there is a defined 1 bit in C
1884  // * C is fully defined
1885  // Si = !(C & ~Sc) && Sc
1886  Value *Zero = Constant::getNullValue(Sc->getType());
1887  Value *MinusOne = Constant::getAllOnesValue(Sc->getType());
1888  Value *Si =
1889  IRB.CreateAnd(IRB.CreateICmpNE(Sc, Zero),
1890  IRB.CreateICmpEQ(
1891  IRB.CreateAnd(IRB.CreateXor(Sc, MinusOne), C), Zero));
1892  Si->setName("_msprop_icmp");
1893  setShadow(&I, Si);
1894  setOriginForNaryOp(I);
1895  }
1896 
1897  /// \brief Build the lowest possible value of V, taking into account V's
1898  /// uninitialized bits.
1899  Value *getLowestPossibleValue(IRBuilder<> &IRB, Value *A, Value *Sa,
1900  bool isSigned) {
1901  if (isSigned) {
1902  // Split shadow into sign bit and other bits.
1903  Value *SaOtherBits = IRB.CreateLShr(IRB.CreateShl(Sa, 1), 1);
1904  Value *SaSignBit = IRB.CreateXor(Sa, SaOtherBits);
1905  // Maximise the undefined shadow bit, minimize other undefined bits.
1906  return
1907  IRB.CreateOr(IRB.CreateAnd(A, IRB.CreateNot(SaOtherBits)), SaSignBit);
1908  } else {
1909  // Minimize undefined bits.
1910  return IRB.CreateAnd(A, IRB.CreateNot(Sa));
1911  }
1912  }
1913 
1914  /// \brief Build the highest possible value of V, taking into account V's
1915  /// uninitialized bits.
1916  Value *getHighestPossibleValue(IRBuilder<> &IRB, Value *A, Value *Sa,
1917  bool isSigned) {
1918  if (isSigned) {
1919  // Split shadow into sign bit and other bits.
1920  Value *SaOtherBits = IRB.CreateLShr(IRB.CreateShl(Sa, 1), 1);
1921  Value *SaSignBit = IRB.CreateXor(Sa, SaOtherBits);
1922  // Minimise the undefined shadow bit, maximise other undefined bits.
1923  return
1924  IRB.CreateOr(IRB.CreateAnd(A, IRB.CreateNot(SaSignBit)), SaOtherBits);
1925  } else {
1926  // Maximize undefined bits.
1927  return IRB.CreateOr(A, Sa);
1928  }
1929  }
1930 
1931  /// \brief Instrument relational comparisons.
1932  ///
1933  /// This function does exact shadow propagation for all relational
1934  /// comparisons of integers, pointers and vectors of those.
1935  /// FIXME: output seems suboptimal when one of the operands is a constant
1936  void handleRelationalComparisonExact(ICmpInst &I) {
1937  IRBuilder<> IRB(&I);
1938  Value *A = I.getOperand(0);
1939  Value *B = I.getOperand(1);
1940  Value *Sa = getShadow(A);
1941  Value *Sb = getShadow(B);
1942 
1943  // Get rid of pointers and vectors of pointers.
1944  // For ints (and vectors of ints), types of A and Sa match,
1945  // and this is a no-op.
1946  A = IRB.CreatePointerCast(A, Sa->getType());
1947  B = IRB.CreatePointerCast(B, Sb->getType());
1948 
1949  // Let [a0, a1] be the interval of possible values of A, taking into account
1950  // its undefined bits. Let [b0, b1] be the interval of possible values of B.
1951  // Then (A cmp B) is defined iff (a0 cmp b1) == (a1 cmp b0).
1952  bool IsSigned = I.isSigned();
1953  Value *S1 = IRB.CreateICmp(I.getPredicate(),
1954  getLowestPossibleValue(IRB, A, Sa, IsSigned),
1955  getHighestPossibleValue(IRB, B, Sb, IsSigned));
1956  Value *S2 = IRB.CreateICmp(I.getPredicate(),
1957  getHighestPossibleValue(IRB, A, Sa, IsSigned),
1958  getLowestPossibleValue(IRB, B, Sb, IsSigned));
1959  Value *Si = IRB.CreateXor(S1, S2);
1960  setShadow(&I, Si);
1961  setOriginForNaryOp(I);
1962  }
1963 
1964  /// \brief Instrument signed relational comparisons.
1965  ///
1966  /// Handle sign bit tests: x<0, x>=0, x<=-1, x>-1 by propagating the highest
1967  /// bit of the shadow. Everything else is delegated to handleShadowOr().
1968  void handleSignedRelationalComparison(ICmpInst &I) {
1969  Constant *constOp;
1970  Value *op = nullptr;
1971  CmpInst::Predicate pre;
1972  if ((constOp = dyn_cast<Constant>(I.getOperand(1)))) {
1973  op = I.getOperand(0);
1974  pre = I.getPredicate();
1975  } else if ((constOp = dyn_cast<Constant>(I.getOperand(0)))) {
1976  op = I.getOperand(1);
1977  pre = I.getSwappedPredicate();
1978  } else {
1979  handleShadowOr(I);
1980  return;
1981  }
1982 
1983  if ((constOp->isNullValue() &&
1984  (pre == CmpInst::ICMP_SLT || pre == CmpInst::ICMP_SGE)) ||
1985  (constOp->isAllOnesValue() &&
1986  (pre == CmpInst::ICMP_SGT || pre == CmpInst::ICMP_SLE))) {
1987  IRBuilder<> IRB(&I);
1988  Value *Shadow = IRB.CreateICmpSLT(getShadow(op), getCleanShadow(op),
1989  "_msprop_icmp_s");
1990  setShadow(&I, Shadow);
1991  setOrigin(&I, getOrigin(op));
1992  } else {
1993  handleShadowOr(I);
1994  }
1995  }
1996 
1997  void visitICmpInst(ICmpInst &I) {
1998  if (!ClHandleICmp) {
1999  handleShadowOr(I);
2000  return;
2001  }
2002  if (I.isEquality()) {
2003  handleEqualityComparison(I);
2004  return;
2005  }
2006 
2007  assert(I.isRelational());
2008  if (ClHandleICmpExact) {
2009  handleRelationalComparisonExact(I);
2010  return;
2011  }
2012  if (I.isSigned()) {
2013  handleSignedRelationalComparison(I);
2014  return;
2015  }
2016 
2017  assert(I.isUnsigned());
2018  if ((isa<Constant>(I.getOperand(0)) || isa<Constant>(I.getOperand(1)))) {
2019  handleRelationalComparisonExact(I);
2020  return;
2021  }
2022 
2023  handleShadowOr(I);
2024  }
2025 
2026  void visitFCmpInst(FCmpInst &I) {
2027  handleShadowOr(I);
2028  }
2029 
2030  void handleShift(BinaryOperator &I) {
2031  IRBuilder<> IRB(&I);
2032  // If any of the S2 bits are poisoned, the whole thing is poisoned.
2033  // Otherwise perform the same shift on S1.
2034  Value *S1 = getShadow(&I, 0);
2035  Value *S2 = getShadow(&I, 1);
2036  Value *S2Conv = IRB.CreateSExt(IRB.CreateICmpNE(S2, getCleanShadow(S2)),
2037  S2->getType());
2038  Value *V2 = I.getOperand(1);
2039  Value *Shift = IRB.CreateBinOp(I.getOpcode(), S1, V2);
2040  setShadow(&I, IRB.CreateOr(Shift, S2Conv));
2041  setOriginForNaryOp(I);
2042  }
2043 
2044  void visitShl(BinaryOperator &I) { handleShift(I); }
2045  void visitAShr(BinaryOperator &I) { handleShift(I); }
2046  void visitLShr(BinaryOperator &I) { handleShift(I); }
2047 
2048  /// \brief Instrument llvm.memmove
2049  ///
2050  /// At this point we don't know if llvm.memmove will be inlined or not.
2051  /// If we don't instrument it and it gets inlined,
2052  /// our interceptor will not kick in and we will lose the memmove.
2053  /// If we instrument the call here, but it does not get inlined,
2054  /// we will memove the shadow twice: which is bad in case
2055  /// of overlapping regions. So, we simply lower the intrinsic to a call.
2056  ///
2057  /// Similar situation exists for memcpy and memset.
2058  void visitMemMoveInst(MemMoveInst &I) {
2059  IRBuilder<> IRB(&I);
2060  IRB.CreateCall(
2061  MS.MemmoveFn,
2062  {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()),
2063  IRB.CreatePointerCast(I.getArgOperand(1), IRB.getInt8PtrTy()),
2064  IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)});
2065  I.eraseFromParent();
2066  }
2067 
2068  // Similar to memmove: avoid copying shadow twice.
2069  // This is somewhat unfortunate as it may slowdown small constant memcpys.
2070  // FIXME: consider doing manual inline for small constant sizes and proper
2071  // alignment.
2072  void visitMemCpyInst(MemCpyInst &I) {
2073  IRBuilder<> IRB(&I);
2074  IRB.CreateCall(
2075  MS.MemcpyFn,
2076  {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()),
2077  IRB.CreatePointerCast(I.getArgOperand(1), IRB.getInt8PtrTy()),
2078  IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)});
2079  I.eraseFromParent();
2080  }
2081 
2082  // Same as memcpy.
2083  void visitMemSetInst(MemSetInst &I) {
2084  IRBuilder<> IRB(&I);
2085  IRB.CreateCall(
2086  MS.MemsetFn,
2087  {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()),
2088  IRB.CreateIntCast(I.getArgOperand(1), IRB.getInt32Ty(), false),
2089  IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)});
2090  I.eraseFromParent();
2091  }
2092 
2093  void visitVAStartInst(VAStartInst &I) {
2094  VAHelper->visitVAStartInst(I);
2095  }
2096 
2097  void visitVACopyInst(VACopyInst &I) {
2098  VAHelper->visitVACopyInst(I);
2099  }
2100 
2101  /// \brief Handle vector store-like intrinsics.
2102  ///
2103  /// Instrument intrinsics that look like a simple SIMD store: writes memory,
2104  /// has 1 pointer argument and 1 vector argument, returns void.
2105  bool handleVectorStoreIntrinsic(IntrinsicInst &I) {
2106  IRBuilder<> IRB(&I);
2107  Value* Addr = I.getArgOperand(0);
2108  Value *Shadow = getShadow(&I, 1);
2109  Value *ShadowPtr, *OriginPtr;
2110 
2111  // We don't know the pointer alignment (could be unaligned SSE store!).
2112  // Have to assume to worst case.
2113  std::tie(ShadowPtr, OriginPtr) = getShadowOriginPtr(
2114  Addr, IRB, Shadow->getType(), /*Alignment*/ 1, /*isStore*/ true);
2115  IRB.CreateAlignedStore(Shadow, ShadowPtr, 1);
2116 
2118  insertShadowCheck(Addr, &I);
2119 
2120  // FIXME: factor out common code from materializeStores
2121  if (MS.TrackOrigins) IRB.CreateStore(getOrigin(&I, 1), OriginPtr);
2122  return true;
2123  }
2124 
2125  /// \brief Handle vector load-like intrinsics.
2126  ///
2127  /// Instrument intrinsics that look like a simple SIMD load: reads memory,
2128  /// has 1 pointer argument, returns a vector.
2129  bool handleVectorLoadIntrinsic(IntrinsicInst &I) {
2130  IRBuilder<> IRB(&I);
2131  Value *Addr = I.getArgOperand(0);
2132 
2133  Type *ShadowTy = getShadowTy(&I);
2134  Value *ShadowPtr, *OriginPtr;
2135  if (PropagateShadow) {
2136  // We don't know the pointer alignment (could be unaligned SSE load!).
2137  // Have to assume to worst case.
2138  unsigned Alignment = 1;
2139  std::tie(ShadowPtr, OriginPtr) =
2140  getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false);
2141  setShadow(&I, IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_msld"));
2142  } else {
2143  setShadow(&I, getCleanShadow(&I));
2144  }
2145 
2147  insertShadowCheck(Addr, &I);
2148 
2149  if (MS.TrackOrigins) {
2150  if (PropagateShadow)
2151  setOrigin(&I, IRB.CreateLoad(OriginPtr));
2152  else
2153  setOrigin(&I, getCleanOrigin());
2154  }
2155  return true;
2156  }
2157 
2158  /// \brief Handle (SIMD arithmetic)-like intrinsics.
2159  ///
2160  /// Instrument intrinsics with any number of arguments of the same type,
2161  /// equal to the return type. The type should be simple (no aggregates or
2162  /// pointers; vectors are fine).
2163  /// Caller guarantees that this intrinsic does not access memory.
2164  bool maybeHandleSimpleNomemIntrinsic(IntrinsicInst &I) {
2165  Type *RetTy = I.getType();
2166  if (!(RetTy->isIntOrIntVectorTy() ||
2167  RetTy->isFPOrFPVectorTy() ||
2168  RetTy->isX86_MMXTy()))
2169  return false;
2170 
2171  unsigned NumArgOperands = I.getNumArgOperands();
2172 
2173  for (unsigned i = 0; i < NumArgOperands; ++i) {
2174  Type *Ty = I.getArgOperand(i)->getType();
2175  if (Ty != RetTy)
2176  return false;
2177  }
2178 
2179  IRBuilder<> IRB(&I);
2180  ShadowAndOriginCombiner SC(this, IRB);
2181  for (unsigned i = 0; i < NumArgOperands; ++i)
2182  SC.Add(I.getArgOperand(i));
2183  SC.Done(&I);
2184 
2185  return true;
2186  }
2187 
2188  /// \brief Heuristically instrument unknown intrinsics.
2189  ///
2190  /// The main purpose of this code is to do something reasonable with all
2191  /// random intrinsics we might encounter, most importantly - SIMD intrinsics.
2192  /// We recognize several classes of intrinsics by their argument types and
2193  /// ModRefBehaviour and apply special intrumentation when we are reasonably
2194  /// sure that we know what the intrinsic does.
2195  ///
2196  /// We special-case intrinsics where this approach fails. See llvm.bswap
2197  /// handling as an example of that.
2198  bool handleUnknownIntrinsic(IntrinsicInst &I) {
2199  unsigned NumArgOperands = I.getNumArgOperands();
2200  if (NumArgOperands == 0)
2201  return false;
2202 
2203  if (NumArgOperands == 2 &&
2204  I.getArgOperand(0)->getType()->isPointerTy() &&
2205  I.getArgOperand(1)->getType()->isVectorTy() &&
2206  I.getType()->isVoidTy() &&
2207  !I.onlyReadsMemory()) {
2208  // This looks like a vector store.
2209  return handleVectorStoreIntrinsic(I);
2210  }
2211 
2212  if (NumArgOperands == 1 &&
2213  I.getArgOperand(0)->getType()->isPointerTy() &&
2214  I.getType()->isVectorTy() &&
2215  I.onlyReadsMemory()) {
2216  // This looks like a vector load.
2217  return handleVectorLoadIntrinsic(I);
2218  }
2219 
2220  if (I.doesNotAccessMemory())
2221  if (maybeHandleSimpleNomemIntrinsic(I))
2222  return true;
2223 
2224  // FIXME: detect and handle SSE maskstore/maskload
2225  return false;
2226  }
2227 
2228  void handleBswap(IntrinsicInst &I) {
2229  IRBuilder<> IRB(&I);
2230  Value *Op = I.getArgOperand(0);
2231  Type *OpType = Op->getType();
2232  Function *BswapFunc = Intrinsic::getDeclaration(
2233  F.getParent(), Intrinsic::bswap, makeArrayRef(&OpType, 1));
2234  setShadow(&I, IRB.CreateCall(BswapFunc, getShadow(Op)));
2235  setOrigin(&I, getOrigin(Op));
2236  }
2237 
2238  // \brief Instrument vector convert instrinsic.
2239  //
2240  // This function instruments intrinsics like cvtsi2ss:
2241  // %Out = int_xxx_cvtyyy(%ConvertOp)
2242  // or
2243  // %Out = int_xxx_cvtyyy(%CopyOp, %ConvertOp)
2244  // Intrinsic converts \p NumUsedElements elements of \p ConvertOp to the same
2245  // number \p Out elements, and (if has 2 arguments) copies the rest of the
2246  // elements from \p CopyOp.
2247  // In most cases conversion involves floating-point value which may trigger a
2248  // hardware exception when not fully initialized. For this reason we require
2249  // \p ConvertOp[0:NumUsedElements] to be fully initialized and trap otherwise.
2250  // We copy the shadow of \p CopyOp[NumUsedElements:] to \p
2251  // Out[NumUsedElements:]. This means that intrinsics without \p CopyOp always
2252  // return a fully initialized value.
2253  void handleVectorConvertIntrinsic(IntrinsicInst &I, int NumUsedElements) {
2254  IRBuilder<> IRB(&I);
2255  Value *CopyOp, *ConvertOp;
2256 
2257  switch (I.getNumArgOperands()) {
2258  case 3:
2259  assert(isa<ConstantInt>(I.getArgOperand(2)) && "Invalid rounding mode");
2261  case 2:
2262  CopyOp = I.getArgOperand(0);
2263  ConvertOp = I.getArgOperand(1);
2264  break;
2265  case 1:
2266  ConvertOp = I.getArgOperand(0);
2267  CopyOp = nullptr;
2268  break;
2269  default:
2270  llvm_unreachable("Cvt intrinsic with unsupported number of arguments.");
2271  }
2272 
2273  // The first *NumUsedElements* elements of ConvertOp are converted to the
2274  // same number of output elements. The rest of the output is copied from
2275  // CopyOp, or (if not available) filled with zeroes.
2276  // Combine shadow for elements of ConvertOp that are used in this operation,
2277  // and insert a check.
2278  // FIXME: consider propagating shadow of ConvertOp, at least in the case of
2279  // int->any conversion.
2280  Value *ConvertShadow = getShadow(ConvertOp);
2281  Value *AggShadow = nullptr;
2282  if (ConvertOp->getType()->isVectorTy()) {
2283  AggShadow = IRB.CreateExtractElement(
2284  ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), 0));
2285  for (int i = 1; i < NumUsedElements; ++i) {
2286  Value *MoreShadow = IRB.CreateExtractElement(
2287  ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), i));
2288  AggShadow = IRB.CreateOr(AggShadow, MoreShadow);
2289  }
2290  } else {
2291  AggShadow = ConvertShadow;
2292  }
2293  assert(AggShadow->getType()->isIntegerTy());
2294  insertShadowCheck(AggShadow, getOrigin(ConvertOp), &I);
2295 
2296  // Build result shadow by zero-filling parts of CopyOp shadow that come from
2297  // ConvertOp.
2298  if (CopyOp) {
2299  assert(CopyOp->getType() == I.getType());
2300  assert(CopyOp->getType()->isVectorTy());
2301  Value *ResultShadow = getShadow(CopyOp);
2302  Type *EltTy = ResultShadow->getType()->getVectorElementType();
2303  for (int i = 0; i < NumUsedElements; ++i) {
2304  ResultShadow = IRB.CreateInsertElement(
2305  ResultShadow, ConstantInt::getNullValue(EltTy),
2306  ConstantInt::get(IRB.getInt32Ty(), i));
2307  }
2308  setShadow(&I, ResultShadow);
2309  setOrigin(&I, getOrigin(CopyOp));
2310  } else {
2311  setShadow(&I, getCleanShadow(&I));
2312  setOrigin(&I, getCleanOrigin());
2313  }
2314  }
2315 
2316  // Given a scalar or vector, extract lower 64 bits (or less), and return all
2317  // zeroes if it is zero, and all ones otherwise.
2318  Value *Lower64ShadowExtend(IRBuilder<> &IRB, Value *S, Type *T) {
2319  if (S->getType()->isVectorTy())
2320  S = CreateShadowCast(IRB, S, IRB.getInt64Ty(), /* Signed */ true);
2321  assert(S->getType()->getPrimitiveSizeInBits() <= 64);
2322  Value *S2 = IRB.CreateICmpNE(S, getCleanShadow(S));
2323  return CreateShadowCast(IRB, S2, T, /* Signed */ true);
2324  }
2325 
2326  // Given a vector, extract its first element, and return all
2327  // zeroes if it is zero, and all ones otherwise.
2328  Value *LowerElementShadowExtend(IRBuilder<> &IRB, Value *S, Type *T) {
2329  Value *S1 = IRB.CreateExtractElement(S, (uint64_t)0);
2330  Value *S2 = IRB.CreateICmpNE(S1, getCleanShadow(S1));
2331  return CreateShadowCast(IRB, S2, T, /* Signed */ true);
2332  }
2333 
2334  Value *VariableShadowExtend(IRBuilder<> &IRB, Value *S) {
2335  Type *T = S->getType();
2336  assert(T->isVectorTy());
2337  Value *S2 = IRB.CreateICmpNE(S, getCleanShadow(S));
2338  return IRB.CreateSExt(S2, T);
2339  }
2340 
2341  // \brief Instrument vector shift instrinsic.
2342  //
2343  // This function instruments intrinsics like int_x86_avx2_psll_w.
2344  // Intrinsic shifts %In by %ShiftSize bits.
2345  // %ShiftSize may be a vector. In that case the lower 64 bits determine shift
2346  // size, and the rest is ignored. Behavior is defined even if shift size is
2347  // greater than register (or field) width.
2348  void handleVectorShiftIntrinsic(IntrinsicInst &I, bool Variable) {
2349  assert(I.getNumArgOperands() == 2);
2350  IRBuilder<> IRB(&I);
2351  // If any of the S2 bits are poisoned, the whole thing is poisoned.
2352  // Otherwise perform the same shift on S1.
2353  Value *S1 = getShadow(&I, 0);
2354  Value *S2 = getShadow(&I, 1);
2355  Value *S2Conv = Variable ? VariableShadowExtend(IRB, S2)
2356  : Lower64ShadowExtend(IRB, S2, getShadowTy(&I));
2357  Value *V1 = I.getOperand(0);
2358  Value *V2 = I.getOperand(1);
2359  Value *Shift = IRB.CreateCall(I.getCalledValue(),
2360  {IRB.CreateBitCast(S1, V1->getType()), V2});
2361  Shift = IRB.CreateBitCast(Shift, getShadowTy(&I));
2362  setShadow(&I, IRB.CreateOr(Shift, S2Conv));
2363  setOriginForNaryOp(I);
2364  }
2365 
2366  // \brief Get an X86_MMX-sized vector type.
2367  Type *getMMXVectorTy(unsigned EltSizeInBits) {
2368  const unsigned X86_MMXSizeInBits = 64;
2369  return VectorType::get(IntegerType::get(*MS.C, EltSizeInBits),
2370  X86_MMXSizeInBits / EltSizeInBits);
2371  }
2372 
2373  // \brief Returns a signed counterpart for an (un)signed-saturate-and-pack
2374  // intrinsic.
2375  Intrinsic::ID getSignedPackIntrinsic(Intrinsic::ID id) {
2376  switch (id) {
2377  case Intrinsic::x86_sse2_packsswb_128:
2378  case Intrinsic::x86_sse2_packuswb_128:
2379  return Intrinsic::x86_sse2_packsswb_128;
2380 
2381  case Intrinsic::x86_sse2_packssdw_128:
2382  case Intrinsic::x86_sse41_packusdw:
2383  return Intrinsic::x86_sse2_packssdw_128;
2384 
2385  case Intrinsic::x86_avx2_packsswb:
2386  case Intrinsic::x86_avx2_packuswb:
2387  return Intrinsic::x86_avx2_packsswb;
2388 
2389  case Intrinsic::x86_avx2_packssdw:
2390  case Intrinsic::x86_avx2_packusdw:
2391  return Intrinsic::x86_avx2_packssdw;
2392 
2393  case Intrinsic::x86_mmx_packsswb:
2394  case Intrinsic::x86_mmx_packuswb:
2395  return Intrinsic::x86_mmx_packsswb;
2396 
2397  case Intrinsic::x86_mmx_packssdw:
2398  return Intrinsic::x86_mmx_packssdw;
2399  default:
2400  llvm_unreachable("unexpected intrinsic id");
2401  }
2402  }
2403 
2404  // \brief Instrument vector pack instrinsic.
2405  //
2406  // This function instruments intrinsics like x86_mmx_packsswb, that
2407  // packs elements of 2 input vectors into half as many bits with saturation.
2408  // Shadow is propagated with the signed variant of the same intrinsic applied
2409  // to sext(Sa != zeroinitializer), sext(Sb != zeroinitializer).
2410  // EltSizeInBits is used only for x86mmx arguments.
2411  void handleVectorPackIntrinsic(IntrinsicInst &I, unsigned EltSizeInBits = 0) {
2412  assert(I.getNumArgOperands() == 2);
2413  bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
2414  IRBuilder<> IRB(&I);
2415  Value *S1 = getShadow(&I, 0);
2416  Value *S2 = getShadow(&I, 1);
2417  assert(isX86_MMX || S1->getType()->isVectorTy());
2418 
2419  // SExt and ICmpNE below must apply to individual elements of input vectors.
2420  // In case of x86mmx arguments, cast them to appropriate vector types and
2421  // back.
2422  Type *T = isX86_MMX ? getMMXVectorTy(EltSizeInBits) : S1->getType();
2423  if (isX86_MMX) {
2424  S1 = IRB.CreateBitCast(S1, T);
2425  S2 = IRB.CreateBitCast(S2, T);
2426  }
2427  Value *S1_ext = IRB.CreateSExt(
2428  IRB.CreateICmpNE(S1, Constant::getNullValue(T)), T);
2429  Value *S2_ext = IRB.CreateSExt(
2430  IRB.CreateICmpNE(S2, Constant::getNullValue(T)), T);
2431  if (isX86_MMX) {
2432  Type *X86_MMXTy = Type::getX86_MMXTy(*MS.C);
2433  S1_ext = IRB.CreateBitCast(S1_ext, X86_MMXTy);
2434  S2_ext = IRB.CreateBitCast(S2_ext, X86_MMXTy);
2435  }
2436 
2437  Function *ShadowFn = Intrinsic::getDeclaration(
2438  F.getParent(), getSignedPackIntrinsic(I.getIntrinsicID()));
2439 
2440  Value *S =
2441  IRB.CreateCall(ShadowFn, {S1_ext, S2_ext}, "_msprop_vector_pack");
2442  if (isX86_MMX) S = IRB.CreateBitCast(S, getShadowTy(&I));
2443  setShadow(&I, S);
2444  setOriginForNaryOp(I);
2445  }
2446 
2447  // \brief Instrument sum-of-absolute-differencies intrinsic.
2448  void handleVectorSadIntrinsic(IntrinsicInst &I) {
2449  const unsigned SignificantBitsPerResultElement = 16;
2450  bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
2451  Type *ResTy = isX86_MMX ? IntegerType::get(*MS.C, 64) : I.getType();
2452  unsigned ZeroBitsPerResultElement =
2453  ResTy->getScalarSizeInBits() - SignificantBitsPerResultElement;
2454 
2455  IRBuilder<> IRB(&I);
2456  Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2457  S = IRB.CreateBitCast(S, ResTy);
2458  S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)),
2459  ResTy);
2460  S = IRB.CreateLShr(S, ZeroBitsPerResultElement);
2461  S = IRB.CreateBitCast(S, getShadowTy(&I));
2462  setShadow(&I, S);
2463  setOriginForNaryOp(I);
2464  }
2465 
2466  // \brief Instrument multiply-add intrinsic.
2467  void handleVectorPmaddIntrinsic(IntrinsicInst &I,
2468  unsigned EltSizeInBits = 0) {
2469  bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
2470  Type *ResTy = isX86_MMX ? getMMXVectorTy(EltSizeInBits * 2) : I.getType();
2471  IRBuilder<> IRB(&I);
2472  Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2473  S = IRB.CreateBitCast(S, ResTy);
2474  S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)),
2475  ResTy);
2476  S = IRB.CreateBitCast(S, getShadowTy(&I));
2477  setShadow(&I, S);
2478  setOriginForNaryOp(I);
2479  }
2480 
2481  // \brief Instrument compare-packed intrinsic.
2482  // Basically, an or followed by sext(icmp ne 0) to end up with all-zeros or
2483  // all-ones shadow.
2484  void handleVectorComparePackedIntrinsic(IntrinsicInst &I) {
2485  IRBuilder<> IRB(&I);
2486  Type *ResTy = getShadowTy(&I);
2487  Value *S0 = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2488  Value *S = IRB.CreateSExt(
2489  IRB.CreateICmpNE(S0, Constant::getNullValue(ResTy)), ResTy);
2490  setShadow(&I, S);
2491  setOriginForNaryOp(I);
2492  }
2493 
2494  // \brief Instrument compare-scalar intrinsic.
2495  // This handles both cmp* intrinsics which return the result in the first
2496  // element of a vector, and comi* which return the result as i32.
2497  void handleVectorCompareScalarIntrinsic(IntrinsicInst &I) {
2498  IRBuilder<> IRB(&I);
2499  Value *S0 = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2500  Value *S = LowerElementShadowExtend(IRB, S0, getShadowTy(&I));
2501  setShadow(&I, S);
2502  setOriginForNaryOp(I);
2503  }
2504 
2505  void handleStmxcsr(IntrinsicInst &I) {
2506  IRBuilder<> IRB(&I);
2507  Value* Addr = I.getArgOperand(0);
2508  Type *Ty = IRB.getInt32Ty();
2509  Value *ShadowPtr =
2510  getShadowOriginPtr(Addr, IRB, Ty, /*Alignment*/ 1, /*isStore*/ true)
2511  .first;
2512 
2513  IRB.CreateStore(getCleanShadow(Ty),
2514  IRB.CreatePointerCast(ShadowPtr, Ty->getPointerTo()));
2515 
2517  insertShadowCheck(Addr, &I);
2518  }
2519 
2520  void handleLdmxcsr(IntrinsicInst &I) {
2521  if (!InsertChecks) return;
2522 
2523  IRBuilder<> IRB(&I);
2524  Value *Addr = I.getArgOperand(0);
2525  Type *Ty = IRB.getInt32Ty();
2526  unsigned Alignment = 1;
2527  Value *ShadowPtr, *OriginPtr;
2528  std::tie(ShadowPtr, OriginPtr) =
2529  getShadowOriginPtr(Addr, IRB, Ty, Alignment, /*isStore*/ false);
2530 
2532  insertShadowCheck(Addr, &I);
2533 
2534  Value *Shadow = IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_ldmxcsr");
2535  Value *Origin =
2536  MS.TrackOrigins ? IRB.CreateLoad(OriginPtr) : getCleanOrigin();
2537  insertShadowCheck(Shadow, Origin, &I);
2538  }
2539 
2540  void visitIntrinsicInst(IntrinsicInst &I) {
2541  switch (I.getIntrinsicID()) {
2542  case Intrinsic::bswap:
2543  handleBswap(I);
2544  break;
2545  case Intrinsic::x86_sse_stmxcsr:
2546  handleStmxcsr(I);
2547  break;
2548  case Intrinsic::x86_sse_ldmxcsr:
2549  handleLdmxcsr(I);
2550  break;
2551  case Intrinsic::x86_avx512_vcvtsd2usi64:
2552  case Intrinsic::x86_avx512_vcvtsd2usi32:
2553  case Intrinsic::x86_avx512_vcvtss2usi64:
2554  case Intrinsic::x86_avx512_vcvtss2usi32:
2555  case Intrinsic::x86_avx512_cvttss2usi64:
2556  case Intrinsic::x86_avx512_cvttss2usi:
2557  case Intrinsic::x86_avx512_cvttsd2usi64:
2558  case Intrinsic::x86_avx512_cvttsd2usi:
2559  case Intrinsic::x86_avx512_cvtusi2sd:
2560  case Intrinsic::x86_avx512_cvtusi2ss:
2561  case Intrinsic::x86_avx512_cvtusi642sd:
2562  case Intrinsic::x86_avx512_cvtusi642ss:
2563  case Intrinsic::x86_sse2_cvtsd2si64:
2564  case Intrinsic::x86_sse2_cvtsd2si:
2565  case Intrinsic::x86_sse2_cvtsd2ss:
2566  case Intrinsic::x86_sse2_cvtsi2sd:
2567  case Intrinsic::x86_sse2_cvtsi642sd:
2568  case Intrinsic::x86_sse2_cvtss2sd:
2569  case Intrinsic::x86_sse2_cvttsd2si64:
2570  case Intrinsic::x86_sse2_cvttsd2si:
2571  case Intrinsic::x86_sse_cvtsi2ss:
2572  case Intrinsic::x86_sse_cvtsi642ss:
2573  case Intrinsic::x86_sse_cvtss2si64:
2574  case Intrinsic::x86_sse_cvtss2si:
2575  case Intrinsic::x86_sse_cvttss2si64:
2576  case Intrinsic::x86_sse_cvttss2si:
2577  handleVectorConvertIntrinsic(I, 1);
2578  break;
2579  case Intrinsic::x86_sse_cvtps2pi:
2580  case Intrinsic::x86_sse_cvttps2pi:
2581  handleVectorConvertIntrinsic(I, 2);
2582  break;
2583 
2584  case Intrinsic::x86_avx512_psll_w_512:
2585  case Intrinsic::x86_avx512_psll_d_512:
2586  case Intrinsic::x86_avx512_psll_q_512:
2587  case Intrinsic::x86_avx512_pslli_w_512:
2588  case Intrinsic::x86_avx512_pslli_d_512:
2589  case Intrinsic::x86_avx512_pslli_q_512:
2590  case Intrinsic::x86_avx512_psrl_w_512:
2591  case Intrinsic::x86_avx512_psrl_d_512:
2592  case Intrinsic::x86_avx512_psrl_q_512:
2593  case Intrinsic::x86_avx512_psra_w_512:
2594  case Intrinsic::x86_avx512_psra_d_512:
2595  case Intrinsic::x86_avx512_psra_q_512:
2596  case Intrinsic::x86_avx512_psrli_w_512:
2597  case Intrinsic::x86_avx512_psrli_d_512:
2598  case Intrinsic::x86_avx512_psrli_q_512:
2599  case Intrinsic::x86_avx512_psrai_w_512:
2600  case Intrinsic::x86_avx512_psrai_d_512:
2601  case Intrinsic::x86_avx512_psrai_q_512:
2602  case Intrinsic::x86_avx512_psra_q_256:
2603  case Intrinsic::x86_avx512_psra_q_128:
2604  case Intrinsic::x86_avx512_psrai_q_256:
2605  case Intrinsic::x86_avx512_psrai_q_128:
2606  case Intrinsic::x86_avx2_psll_w:
2607  case Intrinsic::x86_avx2_psll_d:
2608  case Intrinsic::x86_avx2_psll_q:
2609  case Intrinsic::x86_avx2_pslli_w:
2610  case Intrinsic::x86_avx2_pslli_d:
2611  case Intrinsic::x86_avx2_pslli_q:
2612  case Intrinsic::x86_avx2_psrl_w:
2613  case Intrinsic::x86_avx2_psrl_d:
2614  case Intrinsic::x86_avx2_psrl_q:
2615  case Intrinsic::x86_avx2_psra_w:
2616  case Intrinsic::x86_avx2_psra_d:
2617  case Intrinsic::x86_avx2_psrli_w:
2618  case Intrinsic::x86_avx2_psrli_d:
2619  case Intrinsic::x86_avx2_psrli_q:
2620  case Intrinsic::x86_avx2_psrai_w:
2621  case Intrinsic::x86_avx2_psrai_d:
2622  case Intrinsic::x86_sse2_psll_w:
2623  case Intrinsic::x86_sse2_psll_d:
2624  case Intrinsic::x86_sse2_psll_q:
2625  case Intrinsic::x86_sse2_pslli_w:
2626  case Intrinsic::x86_sse2_pslli_d:
2627  case Intrinsic::x86_sse2_pslli_q:
2628  case Intrinsic::x86_sse2_psrl_w:
2629  case Intrinsic::x86_sse2_psrl_d:
2630  case Intrinsic::x86_sse2_psrl_q:
2631  case Intrinsic::x86_sse2_psra_w:
2632  case Intrinsic::x86_sse2_psra_d:
2633  case Intrinsic::x86_sse2_psrli_w:
2634  case Intrinsic::x86_sse2_psrli_d:
2635  case Intrinsic::x86_sse2_psrli_q:
2636  case Intrinsic::x86_sse2_psrai_w:
2637  case Intrinsic::x86_sse2_psrai_d:
2638  case Intrinsic::x86_mmx_psll_w:
2639  case Intrinsic::x86_mmx_psll_d:
2640  case Intrinsic::x86_mmx_psll_q:
2641  case Intrinsic::x86_mmx_pslli_w:
2642  case Intrinsic::x86_mmx_pslli_d:
2643  case Intrinsic::x86_mmx_pslli_q:
2644  case Intrinsic::x86_mmx_psrl_w:
2645  case Intrinsic::x86_mmx_psrl_d:
2646  case Intrinsic::x86_mmx_psrl_q:
2647  case Intrinsic::x86_mmx_psra_w:
2648  case Intrinsic::x86_mmx_psra_d:
2649  case Intrinsic::x86_mmx_psrli_w:
2650  case Intrinsic::x86_mmx_psrli_d:
2651  case Intrinsic::x86_mmx_psrli_q:
2652  case Intrinsic::x86_mmx_psrai_w:
2653  case Intrinsic::x86_mmx_psrai_d:
2654  handleVectorShiftIntrinsic(I, /* Variable */ false);
2655  break;
2656  case Intrinsic::x86_avx2_psllv_d:
2657  case Intrinsic::x86_avx2_psllv_d_256:
2658  case Intrinsic::x86_avx512_psllv_d_512:
2659  case Intrinsic::x86_avx2_psllv_q:
2660  case Intrinsic::x86_avx2_psllv_q_256:
2661  case Intrinsic::x86_avx512_psllv_q_512:
2662  case Intrinsic::x86_avx2_psrlv_d:
2663  case Intrinsic::x86_avx2_psrlv_d_256:
2664  case Intrinsic::x86_avx512_psrlv_d_512:
2665  case Intrinsic::x86_avx2_psrlv_q:
2666  case Intrinsic::x86_avx2_psrlv_q_256:
2667  case Intrinsic::x86_avx512_psrlv_q_512:
2668  case Intrinsic::x86_avx2_psrav_d:
2669  case Intrinsic::x86_avx2_psrav_d_256:
2670  case Intrinsic::x86_avx512_psrav_d_512:
2671  case Intrinsic::x86_avx512_psrav_q_128:
2672  case Intrinsic::x86_avx512_psrav_q_256:
2673  case Intrinsic::x86_avx512_psrav_q_512:
2674  handleVectorShiftIntrinsic(I, /* Variable */ true);
2675  break;
2676 
2677  case Intrinsic::x86_sse2_packsswb_128:
2678  case Intrinsic::x86_sse2_packssdw_128:
2679  case Intrinsic::x86_sse2_packuswb_128:
2680  case Intrinsic::x86_sse41_packusdw:
2681  case Intrinsic::x86_avx2_packsswb:
2682  case Intrinsic::x86_avx2_packssdw:
2683  case Intrinsic::x86_avx2_packuswb:
2684  case Intrinsic::x86_avx2_packusdw:
2685  handleVectorPackIntrinsic(I);
2686  break;
2687 
2688  case Intrinsic::x86_mmx_packsswb:
2689  case Intrinsic::x86_mmx_packuswb:
2690  handleVectorPackIntrinsic(I, 16);
2691  break;
2692 
2693  case Intrinsic::x86_mmx_packssdw:
2694  handleVectorPackIntrinsic(I, 32);
2695  break;
2696 
2697  case Intrinsic::x86_mmx_psad_bw:
2698  case Intrinsic::x86_sse2_psad_bw:
2699  case Intrinsic::x86_avx2_psad_bw:
2700  handleVectorSadIntrinsic(I);
2701  break;
2702 
2703  case Intrinsic::x86_sse2_pmadd_wd:
2704  case Intrinsic::x86_avx2_pmadd_wd:
2705  case Intrinsic::x86_ssse3_pmadd_ub_sw_128:
2706  case Intrinsic::x86_avx2_pmadd_ub_sw:
2707  handleVectorPmaddIntrinsic(I);
2708  break;
2709 
2710  case Intrinsic::x86_ssse3_pmadd_ub_sw:
2711  handleVectorPmaddIntrinsic(I, 8);
2712  break;
2713 
2714  case Intrinsic::x86_mmx_pmadd_wd:
2715  handleVectorPmaddIntrinsic(I, 16);
2716  break;
2717 
2718  case Intrinsic::x86_sse_cmp_ss:
2719  case Intrinsic::x86_sse2_cmp_sd:
2720  case Intrinsic::x86_sse_comieq_ss:
2721  case Intrinsic::x86_sse_comilt_ss:
2722  case Intrinsic::x86_sse_comile_ss:
2723  case Intrinsic::x86_sse_comigt_ss:
2724  case Intrinsic::x86_sse_comige_ss:
2725  case Intrinsic::x86_sse_comineq_ss:
2726  case Intrinsic::x86_sse_ucomieq_ss:
2727  case Intrinsic::x86_sse_ucomilt_ss:
2728  case Intrinsic::x86_sse_ucomile_ss:
2729  case Intrinsic::x86_sse_ucomigt_ss:
2730  case Intrinsic::x86_sse_ucomige_ss:
2731  case Intrinsic::x86_sse_ucomineq_ss:
2732  case Intrinsic::x86_sse2_comieq_sd:
2733  case Intrinsic::x86_sse2_comilt_sd:
2734  case Intrinsic::x86_sse2_comile_sd:
2735  case Intrinsic::x86_sse2_comigt_sd:
2736  case Intrinsic::x86_sse2_comige_sd:
2737  case Intrinsic::x86_sse2_comineq_sd:
2738  case Intrinsic::x86_sse2_ucomieq_sd:
2739  case Intrinsic::x86_sse2_ucomilt_sd:
2740  case Intrinsic::x86_sse2_ucomile_sd:
2741  case Intrinsic::x86_sse2_ucomigt_sd:
2742  case Intrinsic::x86_sse2_ucomige_sd:
2743  case Intrinsic::x86_sse2_ucomineq_sd:
2744  handleVectorCompareScalarIntrinsic(I);
2745  break;
2746 
2747  case Intrinsic::x86_sse_cmp_ps:
2748  case Intrinsic::x86_sse2_cmp_pd:
2749  // FIXME: For x86_avx_cmp_pd_256 and x86_avx_cmp_ps_256 this function
2750  // generates reasonably looking IR that fails in the backend with "Do not
2751  // know how to split the result of this operator!".
2752  handleVectorComparePackedIntrinsic(I);
2753  break;
2754 
2755  default:
2756  if (!handleUnknownIntrinsic(I))
2757  visitInstruction(I);
2758  break;
2759  }
2760  }
2761 
2762  void visitCallSite(CallSite CS) {
2763  Instruction &I = *CS.getInstruction();
2764  assert(!I.getMetadata("nosanitize"));
2765  assert((CS.isCall() || CS.isInvoke()) && "Unknown type of CallSite");
2766  if (CS.isCall()) {
2767  CallInst *Call = cast<CallInst>(&I);
2768 
2769  // For inline asm, do the usual thing: check argument shadow and mark all
2770  // outputs as clean. Note that any side effects of the inline asm that are
2771  // not immediately visible in its constraints are not handled.
2772  if (Call->isInlineAsm()) {
2774  visitAsmInstruction(I);
2775  else
2776  visitInstruction(I);
2777  return;
2778  }
2779 
2780  assert(!isa<IntrinsicInst>(&I) && "intrinsics are handled elsewhere");
2781 
2782  // We are going to insert code that relies on the fact that the callee
2783  // will become a non-readonly function after it is instrumented by us. To
2784  // prevent this code from being optimized out, mark that function
2785  // non-readonly in advance.
2786  if (Function *Func = Call->getCalledFunction()) {
2787  // Clear out readonly/readnone attributes.
2788  AttrBuilder B;
2789  B.addAttribute(Attribute::ReadOnly)
2790  .addAttribute(Attribute::ReadNone);
2792  }
2793 
2795  }
2796  IRBuilder<> IRB(&I);
2797 
2798  unsigned ArgOffset = 0;
2799  DEBUG(dbgs() << " CallSite: " << I << "\n");
2800  for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
2801  ArgIt != End; ++ArgIt) {
2802  Value *A = *ArgIt;
2803  unsigned i = ArgIt - CS.arg_begin();
2804  if (!A->getType()->isSized()) {
2805  DEBUG(dbgs() << "Arg " << i << " is not sized: " << I << "\n");
2806  continue;
2807  }
2808  unsigned Size = 0;
2809  Value *Store = nullptr;
2810  // Compute the Shadow for arg even if it is ByVal, because
2811  // in that case getShadow() will copy the actual arg shadow to
2812  // __msan_param_tls.
2813  Value *ArgShadow = getShadow(A);
2814  Value *ArgShadowBase = getShadowPtrForArgument(A, IRB, ArgOffset);
2815  DEBUG(dbgs() << " Arg#" << i << ": " << *A <<
2816  " Shadow: " << *ArgShadow << "\n");
2817  bool ArgIsInitialized = false;
2818  const DataLayout &DL = F.getParent()->getDataLayout();
2819  if (CS.paramHasAttr(i, Attribute::ByVal)) {
2820  assert(A->getType()->isPointerTy() &&
2821  "ByVal argument is not a pointer!");
2822  Size = DL.getTypeAllocSize(A->getType()->getPointerElementType());
2823  if (ArgOffset + Size > kParamTLSSize) break;
2824  unsigned ParamAlignment = CS.getParamAlignment(i);
2825  unsigned Alignment = std::min(ParamAlignment, kShadowTLSAlignment);
2826  Value *AShadowPtr = getShadowOriginPtr(A, IRB, IRB.getInt8Ty(),
2827  Alignment, /*isStore*/ false)
2828  .first;
2829 
2830  Store = IRB.CreateMemCpy(ArgShadowBase, Alignment, AShadowPtr,
2831  Alignment, Size);
2832  } else {
2833  Size = DL.getTypeAllocSize(A->getType());
2834  if (ArgOffset + Size > kParamTLSSize) break;
2835  Store = IRB.CreateAlignedStore(ArgShadow, ArgShadowBase,
2836  kShadowTLSAlignment);
2837  Constant *Cst = dyn_cast<Constant>(ArgShadow);
2838  if (Cst && Cst->isNullValue()) ArgIsInitialized = true;
2839  }
2840  if (MS.TrackOrigins && !ArgIsInitialized)
2841  IRB.CreateStore(getOrigin(A),
2842  getOriginPtrForArgument(A, IRB, ArgOffset));
2843  (void)Store;
2844  assert(Size != 0 && Store != nullptr);
2845  DEBUG(dbgs() << " Param:" << *Store << "\n");
2846  ArgOffset += alignTo(Size, 8);
2847  }
2848  DEBUG(dbgs() << " done with call args\n");
2849 
2850  FunctionType *FT =
2851  cast<FunctionType>(CS.getCalledValue()->getType()->getContainedType(0));
2852  if (FT->isVarArg()) {
2853  VAHelper->visitCallSite(CS, IRB);
2854  }
2855 
2856  // Now, get the shadow for the RetVal.
2857  if (!I.getType()->isSized()) return;
2858  // Don't emit the epilogue for musttail call returns.
2859  if (CS.isCall() && cast<CallInst>(&I)->isMustTailCall()) return;
2860  IRBuilder<> IRBBefore(&I);
2861  // Until we have full dynamic coverage, make sure the retval shadow is 0.
2862  Value *Base = getShadowPtrForRetval(&I, IRBBefore);
2863  IRBBefore.CreateAlignedStore(getCleanShadow(&I), Base, kShadowTLSAlignment);
2864  BasicBlock::iterator NextInsn;
2865  if (CS.isCall()) {
2866  NextInsn = ++I.getIterator();
2867  assert(NextInsn != I.getParent()->end());
2868  } else {
2869  BasicBlock *NormalDest = cast<InvokeInst>(&I)->getNormalDest();
2870  if (!NormalDest->getSinglePredecessor()) {
2871  // FIXME: this case is tricky, so we are just conservative here.
2872  // Perhaps we need to split the edge between this BB and NormalDest,
2873  // but a naive attempt to use SplitEdge leads to a crash.
2874  setShadow(&I, getCleanShadow(&I));
2875  setOrigin(&I, getCleanOrigin());
2876  return;
2877  }
2878  // FIXME: NextInsn is likely in a basic block that has not been visited yet.
2879  // Anything inserted there will be instrumented by MSan later!
2880  NextInsn = NormalDest->getFirstInsertionPt();
2881  assert(NextInsn != NormalDest->end() &&
2882  "Could not find insertion point for retval shadow load");
2883  }
2884  IRBuilder<> IRBAfter(&*NextInsn);
2885  Value *RetvalShadow =
2886  IRBAfter.CreateAlignedLoad(getShadowPtrForRetval(&I, IRBAfter),
2887  kShadowTLSAlignment, "_msret");
2888  setShadow(&I, RetvalShadow);
2889  if (MS.TrackOrigins)
2890  setOrigin(&I, IRBAfter.CreateLoad(getOriginPtrForRetval(IRBAfter)));
2891  }
2892 
2893  bool isAMustTailRetVal(Value *RetVal) {
2894  if (auto *I = dyn_cast<BitCastInst>(RetVal)) {
2895  RetVal = I->getOperand(0);
2896  }
2897  if (auto *I = dyn_cast<CallInst>(RetVal)) {
2898  return I->isMustTailCall();
2899  }
2900  return false;
2901  }
2902 
2903  void visitReturnInst(ReturnInst &I) {
2904  IRBuilder<> IRB(&I);
2905  Value *RetVal = I.getReturnValue();
2906  if (!RetVal) return;
2907  // Don't emit the epilogue for musttail call returns.
2908  if (isAMustTailRetVal(RetVal)) return;
2909  Value *ShadowPtr = getShadowPtrForRetval(RetVal, IRB);
2910  if (CheckReturnValue) {
2911  insertShadowCheck(RetVal, &I);
2912  Value *Shadow = getCleanShadow(RetVal);
2913  IRB.CreateAlignedStore(Shadow, ShadowPtr, kShadowTLSAlignment);
2914  } else {
2915  Value *Shadow = getShadow(RetVal);
2916  IRB.CreateAlignedStore(Shadow, ShadowPtr, kShadowTLSAlignment);
2917  if (MS.TrackOrigins)
2918  IRB.CreateStore(getOrigin(RetVal), getOriginPtrForRetval(IRB));
2919  }
2920  }
2921 
2922  void visitPHINode(PHINode &I) {
2923  IRBuilder<> IRB(&I);
2924  if (!PropagateShadow) {
2925  setShadow(&I, getCleanShadow(&I));
2926  setOrigin(&I, getCleanOrigin());
2927  return;
2928  }
2929 
2930  ShadowPHINodes.push_back(&I);
2931  setShadow(&I, IRB.CreatePHI(getShadowTy(&I), I.getNumIncomingValues(),
2932  "_msphi_s"));
2933  if (MS.TrackOrigins)
2934  setOrigin(&I, IRB.CreatePHI(MS.OriginTy, I.getNumIncomingValues(),
2935  "_msphi_o"));
2936  }
2937 
2938  void visitAllocaInst(AllocaInst &I) {
2939  setShadow(&I, getCleanShadow(&I));
2940  setOrigin(&I, getCleanOrigin());
2941  IRBuilder<> IRB(I.getNextNode());
2942  const DataLayout &DL = F.getParent()->getDataLayout();
2943  uint64_t TypeSize = DL.getTypeAllocSize(I.getAllocatedType());
2944  Value *Len = ConstantInt::get(MS.IntptrTy, TypeSize);
2945  if (I.isArrayAllocation())
2946  Len = IRB.CreateMul(Len, I.getArraySize());
2947  if (PoisonStack && ClPoisonStackWithCall) {
2948  IRB.CreateCall(MS.MsanPoisonStackFn,
2949  {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len});
2950  } else {
2951  Value *ShadowBase = getShadowOriginPtr(&I, IRB, IRB.getInt8Ty(),
2952  I.getAlignment(), /*isStore*/ true)
2953  .first;
2954 
2955  Value *PoisonValue = IRB.getInt8(PoisonStack ? ClPoisonStackPattern : 0);
2956  IRB.CreateMemSet(ShadowBase, PoisonValue, Len, I.getAlignment());
2957  }
2958 
2959  if (PoisonStack && MS.TrackOrigins) {
2960  SmallString<2048> StackDescriptionStorage;
2961  raw_svector_ostream StackDescription(StackDescriptionStorage);
2962  // We create a string with a description of the stack allocation and
2963  // pass it into __msan_set_alloca_origin.
2964  // It will be printed by the run-time if stack-originated UMR is found.
2965  // The first 4 bytes of the string are set to '----' and will be replaced
2966  // by __msan_va_arg_overflow_size_tls at the first call.
2967  StackDescription << "----" << I.getName() << "@" << F.getName();
2968  Value *Descr =
2970  StackDescription.str());
2971 
2972  IRB.CreateCall(MS.MsanSetAllocaOrigin4Fn,
2973  {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len,
2974  IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy()),
2975  IRB.CreatePointerCast(&F, MS.IntptrTy)});
2976  }
2977  }
2978 
2979  void visitSelectInst(SelectInst& I) {
2980  IRBuilder<> IRB(&I);
2981  // a = select b, c, d
2982  Value *B = I.getCondition();
2983  Value *C = I.getTrueValue();
2984  Value *D = I.getFalseValue();
2985  Value *Sb = getShadow(B);
2986  Value *Sc = getShadow(C);
2987  Value *Sd = getShadow(D);
2988 
2989  // Result shadow if condition shadow is 0.
2990  Value *Sa0 = IRB.CreateSelect(B, Sc, Sd);
2991  Value *Sa1;
2992  if (I.getType()->isAggregateType()) {
2993  // To avoid "sign extending" i1 to an arbitrary aggregate type, we just do
2994  // an extra "select". This results in much more compact IR.
2995  // Sa = select Sb, poisoned, (select b, Sc, Sd)
2996  Sa1 = getPoisonedShadow(getShadowTy(I.getType()));
2997  } else {
2998  // Sa = select Sb, [ (c^d) | Sc | Sd ], [ b ? Sc : Sd ]
2999  // If Sb (condition is poisoned), look for bits in c and d that are equal
3000  // and both unpoisoned.
3001  // If !Sb (condition is unpoisoned), simply pick one of Sc and Sd.
3002 
3003  // Cast arguments to shadow-compatible type.
3004  C = CreateAppToShadowCast(IRB, C);
3005  D = CreateAppToShadowCast(IRB, D);
3006 
3007  // Result shadow if condition shadow is 1.
3008  Sa1 = IRB.CreateOr(IRB.CreateXor(C, D), IRB.CreateOr(Sc, Sd));
3009  }
3010  Value *Sa = IRB.CreateSelect(Sb, Sa1, Sa0, "_msprop_select");
3011  setShadow(&I, Sa);
3012  if (MS.TrackOrigins) {
3013  // Origins are always i32, so any vector conditions must be flattened.
3014  // FIXME: consider tracking vector origins for app vectors?
3015  if (B->getType()->isVectorTy()) {
3016  Type *FlatTy = getShadowTyNoVec(B->getType());
3017  B = IRB.CreateICmpNE(IRB.CreateBitCast(B, FlatTy),
3018  ConstantInt::getNullValue(FlatTy));
3019  Sb = IRB.CreateICmpNE(IRB.CreateBitCast(Sb, FlatTy),
3020  ConstantInt::getNullValue(FlatTy));
3021  }
3022  // a = select b, c, d
3023  // Oa = Sb ? Ob : (b ? Oc : Od)
3024  setOrigin(
3025  &I, IRB.CreateSelect(Sb, getOrigin(I.getCondition()),
3026  IRB.CreateSelect(B, getOrigin(I.getTrueValue()),
3027  getOrigin(I.getFalseValue()))));
3028  }
3029  }
3030 
3031  void visitLandingPadInst(LandingPadInst &I) {
3032  // Do nothing.
3033  // See https://github.com/google/sanitizers/issues/504
3034  setShadow(&I, getCleanShadow(&I));
3035  setOrigin(&I, getCleanOrigin());
3036  }
3037 
3038  void visitCatchSwitchInst(CatchSwitchInst &I) {
3039  setShadow(&I, getCleanShadow(&I));
3040  setOrigin(&I, getCleanOrigin());
3041  }
3042 
3043  void visitFuncletPadInst(FuncletPadInst &I) {
3044  setShadow(&I, getCleanShadow(&I));
3045  setOrigin(&I, getCleanOrigin());
3046  }
3047 
3048  void visitGetElementPtrInst(GetElementPtrInst &I) {
3049  handleShadowOr(I);
3050  }
3051 
3052  void visitExtractValueInst(ExtractValueInst &I) {
3053  IRBuilder<> IRB(&I);
3054  Value *Agg = I.getAggregateOperand();
3055  DEBUG(dbgs() << "ExtractValue: " << I << "\n");
3056  Value *AggShadow = getShadow(Agg);
3057  DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n");
3058  Value *ResShadow = IRB.CreateExtractValue(AggShadow, I.getIndices());
3059  DEBUG(dbgs() << " ResShadow: " << *ResShadow << "\n");
3060  setShadow(&I, ResShadow);
3061  setOriginForNaryOp(I);
3062  }
3063 
3064  void visitInsertValueInst(InsertValueInst &I) {
3065  IRBuilder<> IRB(&I);
3066  DEBUG(dbgs() << "InsertValue: " << I << "\n");
3067  Value *AggShadow = getShadow(I.getAggregateOperand());
3068  Value *InsShadow = getShadow(I.getInsertedValueOperand());
3069  DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n");
3070  DEBUG(dbgs() << " InsShadow: " << *InsShadow << "\n");
3071  Value *Res = IRB.CreateInsertValue(AggShadow, InsShadow, I.getIndices());
3072  DEBUG(dbgs() << " Res: " << *Res << "\n");
3073  setShadow(&I, Res);
3074  setOriginForNaryOp(I);
3075  }
3076 
3077  void dumpInst(Instruction &I) {
3078  if (CallInst *CI = dyn_cast<CallInst>(&I)) {
3079  errs() << "ZZZ call " << CI->getCalledFunction()->getName() << "\n";
3080  } else {
3081  errs() << "ZZZ " << I.getOpcodeName() << "\n";
3082  }
3083  errs() << "QQQ " << I << "\n";
3084  }
3085 
3086  void visitResumeInst(ResumeInst &I) {
3087  DEBUG(dbgs() << "Resume: " << I << "\n");
3088  // Nothing to do here.
3089  }
3090 
3091  void visitCleanupReturnInst(CleanupReturnInst &CRI) {
3092  DEBUG(dbgs() << "CleanupReturn: " << CRI << "\n");
3093  // Nothing to do here.
3094  }
3095 
3096  void visitCatchReturnInst(CatchReturnInst &CRI) {
3097  DEBUG(dbgs() << "CatchReturn: " << CRI << "\n");
3098  // Nothing to do here.
3099  }
3100 
3101  void visitAsmInstruction(Instruction &I) {
3102  // Conservative inline assembly handling: check for poisoned shadow of
3103  // asm() arguments, then unpoison the result and all the memory locations
3104  // pointed to by those arguments.
3105  CallInst *CI = dyn_cast<CallInst>(&I);
3106 
3107  for (size_t i = 0, n = CI->getNumOperands(); i < n; i++) {
3108  Value *Operand = CI->getOperand(i);
3109  if (Operand->getType()->isSized())
3110  insertShadowCheck(Operand, &I);
3111  }
3112  setShadow(&I, getCleanShadow(&I));
3113  setOrigin(&I, getCleanOrigin());
3114  IRBuilder<> IRB(&I);
3115  IRB.SetInsertPoint(I.getNextNode());
3116  for (size_t i = 0, n = CI->getNumOperands(); i < n; i++) {
3117  Value *Operand = CI->getOperand(i);
3118  Type *OpType = Operand->getType();
3119  if (!OpType->isPointerTy())
3120  continue;
3121  Type *ElType = OpType->getPointerElementType();
3122  if (!ElType->isSized())
3123  continue;
3124  Value *ShadowPtr, *OriginPtr;
3125  std::tie(ShadowPtr, OriginPtr) = getShadowOriginPtr(
3126  Operand, IRB, ElType, /*Alignment*/ 1, /*isStore*/ true);
3127  Value *CShadow = getCleanShadow(ElType);
3128  IRB.CreateStore(
3129  CShadow,
3130  IRB.CreatePointerCast(ShadowPtr, CShadow->getType()->getPointerTo()));
3131  }
3132  }
3133 
3134  void visitInstruction(Instruction &I) {
3135  // Everything else: stop propagating and check for poisoned shadow.
3137  dumpInst(I);
3138  DEBUG(dbgs() << "DEFAULT: " << I << "\n");
3139  for (size_t i = 0, n = I.getNumOperands(); i < n; i++) {
3140  Value *Operand = I.getOperand(i);
3141  if (Operand->getType()->isSized())
3142  insertShadowCheck(Operand, &I);
3143  }
3144  setShadow(&I, getCleanShadow(&I));
3145  setOrigin(&I, getCleanOrigin());
3146  }
3147 };
3148 
3149 /// \brief AMD64-specific implementation of VarArgHelper.
3150 struct VarArgAMD64Helper : public VarArgHelper {
3151  // An unfortunate workaround for asymmetric lowering of va_arg stuff.
3152  // See a comment in visitCallSite for more details.
3153  static const unsigned AMD64GpEndOffset = 48; // AMD64 ABI Draft 0.99.6 p3.5.7
3154  static const unsigned AMD64FpEndOffset = 176;
3155 
3156  Function &F;
3157  MemorySanitizer &MS;
3158  MemorySanitizerVisitor &MSV;
3159  Value *VAArgTLSCopy = nullptr;
3160  Value *VAArgOverflowSize = nullptr;
3161 
3162  SmallVector<CallInst*, 16> VAStartInstrumentationList;
3163 
3164  enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory };
3165 
3166  VarArgAMD64Helper(Function &F, MemorySanitizer &MS,
3167  MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {}
3168 
3169  ArgKind classifyArgument(Value* arg) {
3170  // A very rough approximation of X86_64 argument classification rules.
3171  Type *T = arg->getType();
3172  if (T->isFPOrFPVectorTy() || T->isX86_MMXTy())
3173  return AK_FloatingPoint;
3174  if (T->isIntegerTy() && T->getPrimitiveSizeInBits() <= 64)
3175  return AK_GeneralPurpose;
3176  if (T->isPointerTy())
3177  return AK_GeneralPurpose;
3178  return AK_Memory;
3179  }
3180 
3181  // For VarArg functions, store the argument shadow in an ABI-specific format
3182  // that corresponds to va_list layout.
3183  // We do this because Clang lowers va_arg in the frontend, and this pass
3184  // only sees the low level code that deals with va_list internals.
3185  // A much easier alternative (provided that Clang emits va_arg instructions)
3186  // would have been to associate each live instance of va_list with a copy of
3187  // MSanParamTLS, and extract shadow on va_arg() call in the argument list
3188  // order.
3189  void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
3190  unsigned GpOffset = 0;
3191  unsigned FpOffset = AMD64GpEndOffset;
3192  unsigned OverflowOffset = AMD64FpEndOffset;
3193  const DataLayout &DL = F.getParent()->getDataLayout();
3194  for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
3195  ArgIt != End; ++ArgIt) {
3196  Value *A = *ArgIt;
3197  unsigned ArgNo = CS.getArgumentNo(ArgIt);
3198  bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams();
3199  bool IsByVal = CS.paramHasAttr(ArgNo, Attribute::ByVal);
3200  if (IsByVal) {
3201  // ByVal arguments always go to the overflow area.
3202  // Fixed arguments passed through the overflow area will be stepped
3203  // over by va_start, so don't count them towards the offset.
3204  if (IsFixed)
3205  continue;
3206  assert(A->getType()->isPointerTy());
3207  Type *RealTy = A->getType()->getPointerElementType();
3208  uint64_t ArgSize = DL.getTypeAllocSize(RealTy);
3209  Value *ShadowBase =
3210  getShadowPtrForVAArgument(RealTy, IRB, OverflowOffset);
3211  OverflowOffset += alignTo(ArgSize, 8);
3212  Value *ShadowPtr, *OriginPtr;
3213  std::tie(ShadowPtr, OriginPtr) =
3214  MSV.getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), kShadowTLSAlignment,
3215  /*isStore*/ false);
3216 
3217  IRB.CreateMemCpy(ShadowBase, kShadowTLSAlignment, ShadowPtr,
3218  kShadowTLSAlignment, ArgSize);
3219  } else {
3220  ArgKind AK = classifyArgument(A);
3221  if (AK == AK_GeneralPurpose && GpOffset >= AMD64GpEndOffset)
3222  AK = AK_Memory;
3223  if (AK == AK_FloatingPoint && FpOffset >= AMD64FpEndOffset)
3224  AK = AK_Memory;
3225  Value *ShadowBase;
3226  switch (AK) {
3227  case AK_GeneralPurpose:
3228  ShadowBase = getShadowPtrForVAArgument(A->getType(), IRB, GpOffset);
3229  GpOffset += 8;
3230  break;
3231  case AK_FloatingPoint:
3232  ShadowBase = getShadowPtrForVAArgument(A->getType(), IRB, FpOffset);
3233  FpOffset += 16;
3234  break;
3235  case AK_Memory:
3236  if (IsFixed)
3237  continue;
3238  uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
3239  ShadowBase =
3240  getShadowPtrForVAArgument(A->getType(), IRB, OverflowOffset);
3241  OverflowOffset += alignTo(ArgSize, 8);
3242  }
3243  // Take fixed arguments into account for GpOffset and FpOffset,
3244  // but don't actually store shadows for them.
3245  if (IsFixed)
3246  continue;
3247  IRB.CreateAlignedStore(MSV.getShadow(A), ShadowBase,
3249  }
3250  }
3251  Constant *OverflowSize =
3252  ConstantInt::get(IRB.getInt64Ty(), OverflowOffset - AMD64FpEndOffset);
3253  IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS);
3254  }
3255 
3256  /// \brief Compute the shadow address for a given va_arg.
3257  Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
3258  int ArgOffset) {
3259  Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
3260  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
3261  return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
3262  "_msarg");
3263  }
3264 
3265  void unpoisonVAListTagForInst(IntrinsicInst &I) {
3266  IRBuilder<> IRB(&I);
3267  Value *VAListTag = I.getArgOperand(0);
3268  Value *ShadowPtr, *OriginPtr;
3269  unsigned Alignment = 8;
3270  std::tie(ShadowPtr, OriginPtr) =
3271  MSV.getShadowOriginPtr(VAListTag, IRB, IRB.getInt8Ty(), Alignment,
3272  /*isStore*/ true);
3273 
3274  // Unpoison the whole __va_list_tag.
3275  // FIXME: magic ABI constants.
3276  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3277  /* size */ 24, Alignment, false);
3278  // We shouldn't need to zero out the origins, as they're only checked for
3279  // nonzero shadow.
3280  }
3281 
3282  void visitVAStartInst(VAStartInst &I) override {
3284  return;
3285  VAStartInstrumentationList.push_back(&I);
3286  unpoisonVAListTagForInst(I);
3287  }
3288 
3289  void visitVACopyInst(VACopyInst &I) override {
3290  if (F.getCallingConv() == CallingConv::Win64) return;
3291  unpoisonVAListTagForInst(I);
3292  }
3293 
3294  void finalizeInstrumentation() override {
3295  assert(!VAArgOverflowSize && !VAArgTLSCopy &&
3296  "finalizeInstrumentation called twice");
3297  if (!VAStartInstrumentationList.empty()) {
3298  // If there is a va_start in this function, make a backup copy of
3299  // va_arg_tls somewhere in the function entry block.
3300  IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI());
3301  VAArgOverflowSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
3302  Value *CopySize =
3303  IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, AMD64FpEndOffset),
3304  VAArgOverflowSize);
3305  VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
3306  IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize);
3307  }
3308 
3309  // Instrument va_start.
3310  // Copy va_list shadow from the backup copy of the TLS contents.
3311  for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
3312  CallInst *OrigInst = VAStartInstrumentationList[i];
3313  IRBuilder<> IRB(OrigInst->getNextNode());
3314  Value *VAListTag = OrigInst->getArgOperand(0);
3315 
3316  Value *RegSaveAreaPtrPtr = IRB.CreateIntToPtr(
3317  IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
3318  ConstantInt::get(MS.IntptrTy, 16)),
3320  Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
3321  Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
3322  unsigned Alignment = 16;
3323  std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) =
3324  MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(),
3325  Alignment, /*isStore*/ true);
3326  IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment,
3327  AMD64FpEndOffset);
3328  Value *OverflowArgAreaPtrPtr = IRB.CreateIntToPtr(
3329  IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
3330  ConstantInt::get(MS.IntptrTy, 8)),
3332  Value *OverflowArgAreaPtr = IRB.CreateLoad(OverflowArgAreaPtrPtr);
3333  Value *OverflowArgAreaShadowPtr, *OverflowArgAreaOriginPtr;
3334  std::tie(OverflowArgAreaShadowPtr, OverflowArgAreaOriginPtr) =
3335  MSV.getShadowOriginPtr(OverflowArgAreaPtr, IRB, IRB.getInt8Ty(),
3336  Alignment, /*isStore*/ true);
3337  Value *SrcPtr = IRB.CreateConstGEP1_32(IRB.getInt8Ty(), VAArgTLSCopy,
3338  AMD64FpEndOffset);
3339  IRB.CreateMemCpy(OverflowArgAreaShadowPtr, Alignment, SrcPtr, Alignment,
3340  VAArgOverflowSize);
3341  }
3342  }
3343 };
3344 
3345 /// \brief MIPS64-specific implementation of VarArgHelper.
3346 struct VarArgMIPS64Helper : public VarArgHelper {
3347  Function &F;
3348  MemorySanitizer &MS;
3349  MemorySanitizerVisitor &MSV;
3350  Value *VAArgTLSCopy = nullptr;
3351  Value *VAArgSize = nullptr;
3352 
3353  SmallVector<CallInst*, 16> VAStartInstrumentationList;
3354 
3355  VarArgMIPS64Helper(Function &F, MemorySanitizer &MS,
3356  MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {}
3357 
3358  void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
3359  unsigned VAArgOffset = 0;
3360  const DataLayout &DL = F.getParent()->getDataLayout();
3361  for (CallSite::arg_iterator ArgIt = CS.arg_begin() +
3362  CS.getFunctionType()->getNumParams(), End = CS.arg_end();
3363  ArgIt != End; ++ArgIt) {
3364  Triple TargetTriple(F.getParent()->getTargetTriple());
3365  Value *A = *ArgIt;
3366  Value *Base;
3367  uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
3368  if (TargetTriple.getArch() == Triple::mips64) {
3369  // Adjusting the shadow for argument with size < 8 to match the placement
3370  // of bits in big endian system
3371  if (ArgSize < 8)
3372  VAArgOffset += (8 - ArgSize);
3373  }
3374  Base = getShadowPtrForVAArgument(A->getType(), IRB, VAArgOffset);
3375  VAArgOffset += ArgSize;
3376  VAArgOffset = alignTo(VAArgOffset, 8);
3377  IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment);
3378  }
3379 
3380  Constant *TotalVAArgSize = ConstantInt::get(IRB.getInt64Ty(), VAArgOffset);
3381  // Here using VAArgOverflowSizeTLS as VAArgSizeTLS to avoid creation of
3382  // a new class member i.e. it is the total size of all VarArgs.
3383  IRB.CreateStore(TotalVAArgSize, MS.VAArgOverflowSizeTLS);
3384  }
3385 
3386  /// \brief Compute the shadow address for a given va_arg.
3387  Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
3388  int ArgOffset) {
3389  Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
3390  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
3391  return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
3392  "_msarg");
3393  }
3394 
3395  void visitVAStartInst(VAStartInst &I) override {
3396  IRBuilder<> IRB(&I);
3397  VAStartInstrumentationList.push_back(&I);
3398  Value *VAListTag = I.getArgOperand(0);
3399  Value *ShadowPtr, *OriginPtr;
3400  unsigned Alignment = 8;
3401  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
3402  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
3403  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3404  /* size */ 8, Alignment, false);
3405  }
3406 
3407  void visitVACopyInst(VACopyInst &I) override {
3408  IRBuilder<> IRB(&I);
3409  VAStartInstrumentationList.push_back(&I);
3410  Value *VAListTag = I.getArgOperand(0);
3411  Value *ShadowPtr, *OriginPtr;
3412  unsigned Alignment = 8;
3413  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
3414  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
3415  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3416  /* size */ 8, Alignment, false);
3417  }
3418 
3419  void finalizeInstrumentation() override {
3420  assert(!VAArgSize && !VAArgTLSCopy &&
3421  "finalizeInstrumentation called twice");
3422  IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI());
3423  VAArgSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
3424  Value *CopySize = IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, 0),
3425  VAArgSize);
3426 
3427  if (!VAStartInstrumentationList.empty()) {
3428  // If there is a va_start in this function, make a backup copy of
3429  // va_arg_tls somewhere in the function entry block.
3430  VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
3431  IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize);
3432  }
3433 
3434  // Instrument va_start.
3435  // Copy va_list shadow from the backup copy of the TLS contents.
3436  for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
3437  CallInst *OrigInst = VAStartInstrumentationList[i];
3438  IRBuilder<> IRB(OrigInst->getNextNode());
3439  Value *VAListTag = OrigInst->getArgOperand(0);
3440  Value *RegSaveAreaPtrPtr =
3441  IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
3443  Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
3444  Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
3445  unsigned Alignment = 8;
3446  std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) =
3447  MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(),
3448  Alignment, /*isStore*/ true);
3449  IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment,
3450  CopySize);
3451  }
3452  }
3453 };
3454 
3455 /// \brief AArch64-specific implementation of VarArgHelper.
3456 struct VarArgAArch64Helper : public VarArgHelper {
3457  static const unsigned kAArch64GrArgSize = 64;
3458  static const unsigned kAArch64VrArgSize = 128;
3459 
3460  static const unsigned AArch64GrBegOffset = 0;
3461  static const unsigned AArch64GrEndOffset = kAArch64GrArgSize;
3462  // Make VR space aligned to 16 bytes.
3463  static const unsigned AArch64VrBegOffset = AArch64GrEndOffset;
3464  static const unsigned AArch64VrEndOffset = AArch64VrBegOffset
3465  + kAArch64VrArgSize;
3466  static const unsigned AArch64VAEndOffset = AArch64VrEndOffset;
3467 
3468  Function &F;
3469  MemorySanitizer &MS;
3470  MemorySanitizerVisitor &MSV;
3471  Value *VAArgTLSCopy = nullptr;
3472  Value *VAArgOverflowSize = nullptr;
3473 
3474  SmallVector<CallInst*, 16> VAStartInstrumentationList;
3475 
3476  enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory };
3477 
3478  VarArgAArch64Helper(Function &F, MemorySanitizer &MS,
3479  MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {}
3480 
3481  ArgKind classifyArgument(Value* arg) {
3482  Type *T = arg->getType();
3483  if (T->isFPOrFPVectorTy())
3484  return AK_FloatingPoint;
3485  if ((T->isIntegerTy() && T->getPrimitiveSizeInBits() <= 64)
3486  || (T->isPointerTy()))
3487  return AK_GeneralPurpose;
3488  return AK_Memory;
3489  }
3490 
3491  // The instrumentation stores the argument shadow in a non ABI-specific
3492  // format because it does not know which argument is named (since Clang,
3493  // like x86_64 case, lowers the va_args in the frontend and this pass only
3494  // sees the low level code that deals with va_list internals).
3495  // The first seven GR registers are saved in the first 56 bytes of the
3496  // va_arg tls arra, followers by the first 8 FP/SIMD registers, and then
3497  // the remaining arguments.
3498  // Using constant offset within the va_arg TLS array allows fast copy
3499  // in the finalize instrumentation.
3500  void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
3501  unsigned GrOffset = AArch64GrBegOffset;
3502  unsigned VrOffset = AArch64VrBegOffset;
3503  unsigned OverflowOffset = AArch64VAEndOffset;
3504 
3505  const DataLayout &DL = F.getParent()->getDataLayout();
3506  for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
3507  ArgIt != End; ++ArgIt) {
3508  Value *A = *ArgIt;
3509  unsigned ArgNo = CS.getArgumentNo(ArgIt);
3510  bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams();
3511  ArgKind AK = classifyArgument(A);
3512  if (AK == AK_GeneralPurpose && GrOffset >= AArch64GrEndOffset)
3513  AK = AK_Memory;
3514  if (AK == AK_FloatingPoint && VrOffset >= AArch64VrEndOffset)
3515  AK = AK_Memory;
3516  Value *Base;
3517  switch (AK) {
3518  case AK_GeneralPurpose:
3519  Base = getShadowPtrForVAArgument(A->getType(), IRB, GrOffset);
3520  GrOffset += 8;
3521  break;
3522  case AK_FloatingPoint:
3523  Base = getShadowPtrForVAArgument(A->getType(), IRB, VrOffset);
3524  VrOffset += 16;
3525  break;
3526  case AK_Memory:
3527  // Don't count fixed arguments in the overflow area - va_start will
3528  // skip right over them.
3529  if (IsFixed)
3530  continue;
3531  uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
3532  Base = getShadowPtrForVAArgument(A->getType(), IRB, OverflowOffset);
3533  OverflowOffset += alignTo(ArgSize, 8);
3534  break;
3535  }
3536  // Count Gp/Vr fixed arguments to their respective offsets, but don't
3537  // bother to actually store a shadow.
3538  if (IsFixed)
3539  continue;
3540  IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment);
3541  }
3542  Constant *OverflowSize =
3543  ConstantInt::get(IRB.getInt64Ty(), OverflowOffset - AArch64VAEndOffset);
3544  IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS);
3545  }
3546 
3547  /// Compute the shadow address for a given va_arg.
3548  Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
3549  int ArgOffset) {
3550  Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
3551  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
3552  return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
3553  "_msarg");
3554  }
3555 
3556  void visitVAStartInst(VAStartInst &I) override {
3557  IRBuilder<> IRB(&I);
3558  VAStartInstrumentationList.push_back(&I);
3559  Value *VAListTag = I.getArgOperand(0);
3560  Value *ShadowPtr, *OriginPtr;
3561  unsigned Alignment = 8;
3562  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
3563  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
3564  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3565  /* size */ 32, Alignment, false);
3566  }
3567 
3568  void visitVACopyInst(VACopyInst &I) override {
3569  IRBuilder<> IRB(&I);
3570  VAStartInstrumentationList.push_back(&I);
3571  Value *VAListTag = I.getArgOperand(0);
3572  Value *ShadowPtr, *OriginPtr;
3573  unsigned Alignment = 8;
3574  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
3575  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
3576  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3577  /* size */ 32, Alignment, false);
3578  }
3579 
3580  // Retrieve a va_list field of 'void*' size.
3581  Value* getVAField64(IRBuilder<> &IRB, Value *VAListTag, int offset) {
3582  Value *SaveAreaPtrPtr =
3583  IRB.CreateIntToPtr(
3584  IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
3585  ConstantInt::get(MS.IntptrTy, offset)),
3586  Type::getInt64PtrTy(*MS.C));
3587  return IRB.CreateLoad(SaveAreaPtrPtr);
3588  }
3589 
3590  // Retrieve a va_list field of 'int' size.
3591  Value* getVAField32(IRBuilder<> &IRB, Value *VAListTag, int offset) {
3592  Value *SaveAreaPtr =
3593  IRB.CreateIntToPtr(
3594  IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
3595  ConstantInt::get(MS.IntptrTy, offset)),
3596  Type::getInt32PtrTy(*MS.C));
3597  Value *SaveArea32 = IRB.CreateLoad(SaveAreaPtr);
3598  return IRB.CreateSExt(SaveArea32, MS.IntptrTy);
3599  }
3600 
3601  void finalizeInstrumentation() override {
3602  assert(!VAArgOverflowSize && !VAArgTLSCopy &&
3603  "finalizeInstrumentation called twice");
3604  if (!VAStartInstrumentationList.empty()) {
3605  // If there is a va_start in this function, make a backup copy of
3606  // va_arg_tls somewhere in the function entry block.
3607  IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI());
3608  VAArgOverflowSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
3609  Value *CopySize =
3610  IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, AArch64VAEndOffset),
3611  VAArgOverflowSize);
3612  VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
3613  IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize);
3614  }
3615 
3616  Value *GrArgSize = ConstantInt::get(MS.IntptrTy, kAArch64GrArgSize);
3617  Value *VrArgSize = ConstantInt::get(MS.IntptrTy, kAArch64VrArgSize);
3618 
3619  // Instrument va_start, copy va_list shadow from the backup copy of
3620  // the TLS contents.
3621  for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
3622  CallInst *OrigInst = VAStartInstrumentationList[i];
3623  IRBuilder<> IRB(OrigInst->getNextNode());
3624 
3625  Value *VAListTag = OrigInst->getArgOperand(0);
3626 
3627  // The variadic ABI for AArch64 creates two areas to save the incoming
3628  // argument registers (one for 64-bit general register xn-x7 and another
3629  // for 128-bit FP/SIMD vn-v7).
3630  // We need then to propagate the shadow arguments on both regions
3631  // 'va::__gr_top + va::__gr_offs' and 'va::__vr_top + va::__vr_offs'.
3632  // The remaning arguments are saved on shadow for 'va::stack'.
3633  // One caveat is it requires only to propagate the non-named arguments,
3634  // however on the call site instrumentation 'all' the arguments are
3635  // saved. So to copy the shadow values from the va_arg TLS array
3636  // we need to adjust the offset for both GR and VR fields based on
3637  // the __{gr,vr}_offs value (since they are stores based on incoming
3638  // named arguments).
3639 
3640  // Read the stack pointer from the va_list.
3641  Value *StackSaveAreaPtr = getVAField64(IRB, VAListTag, 0);
3642 
3643  // Read both the __gr_top and __gr_off and add them up.
3644  Value *GrTopSaveAreaPtr = getVAField64(IRB, VAListTag, 8);
3645  Value *GrOffSaveArea = getVAField32(IRB, VAListTag, 24);
3646 
3647  Value *GrRegSaveAreaPtr = IRB.CreateAdd(GrTopSaveAreaPtr, GrOffSaveArea);
3648 
3649  // Read both the __vr_top and __vr_off and add them up.
3650  Value *VrTopSaveAreaPtr = getVAField64(IRB, VAListTag, 16);
3651  Value *VrOffSaveArea = getVAField32(IRB, VAListTag, 28);
3652 
3653  Value *VrRegSaveAreaPtr = IRB.CreateAdd(VrTopSaveAreaPtr, VrOffSaveArea);
3654 
3655  // It does not know how many named arguments is being used and, on the
3656  // callsite all the arguments were saved. Since __gr_off is defined as
3657  // '0 - ((8 - named_gr) * 8)', the idea is to just propagate the variadic
3658  // argument by ignoring the bytes of shadow from named arguments.
3659  Value *GrRegSaveAreaShadowPtrOff =
3660  IRB.CreateAdd(GrArgSize, GrOffSaveArea);
3661 
3662  Value *GrRegSaveAreaShadowPtr =
3663  MSV.getShadowOriginPtr(GrRegSaveAreaPtr, IRB, IRB.getInt8Ty(),
3664  /*Alignment*/ 8, /*isStore*/ true)
3665  .first;
3666 
3667  Value *GrSrcPtr = IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy,
3668  GrRegSaveAreaShadowPtrOff);
3669  Value *GrCopySize = IRB.CreateSub(GrArgSize, GrRegSaveAreaShadowPtrOff);
3670 
3671  IRB.CreateMemCpy(GrRegSaveAreaShadowPtr, 8, GrSrcPtr, 8, GrCopySize);
3672 
3673  // Again, but for FP/SIMD values.
3674  Value *VrRegSaveAreaShadowPtrOff =
3675  IRB.CreateAdd(VrArgSize, VrOffSaveArea);
3676 
3677  Value *VrRegSaveAreaShadowPtr =
3678  MSV.getShadowOriginPtr(VrRegSaveAreaPtr, IRB, IRB.getInt8Ty(),
3679  /*Alignment*/ 8, /*isStore*/ true)
3680  .first;
3681 
3682  Value *VrSrcPtr = IRB.CreateInBoundsGEP(
3683  IRB.getInt8Ty(),
3684  IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy,
3685  IRB.getInt32(AArch64VrBegOffset)),
3686  VrRegSaveAreaShadowPtrOff);
3687  Value *VrCopySize = IRB.CreateSub(VrArgSize, VrRegSaveAreaShadowPtrOff);
3688 
3689  IRB.CreateMemCpy(VrRegSaveAreaShadowPtr, 8, VrSrcPtr, 8, VrCopySize);
3690 
3691  // And finally for remaining arguments.
3692  Value *StackSaveAreaShadowPtr =
3693  MSV.getShadowOriginPtr(StackSaveAreaPtr, IRB, IRB.getInt8Ty(),
3694  /*Alignment*/ 16, /*isStore*/ true)
3695  .first;
3696 
3697  Value *StackSrcPtr =
3698  IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy,
3699  IRB.getInt32(AArch64VAEndOffset));
3700 
3701  IRB.CreateMemCpy(StackSaveAreaShadowPtr, 16, StackSrcPtr, 16,
3702  VAArgOverflowSize);
3703  }
3704  }
3705 };
3706 
3707 /// \brief PowerPC64-specific implementation of VarArgHelper.
3708 struct VarArgPowerPC64Helper : public VarArgHelper {
3709  Function &F;
3710  MemorySanitizer &MS;
3711  MemorySanitizerVisitor &MSV;
3712  Value *VAArgTLSCopy = nullptr;
3713  Value *VAArgSize = nullptr;
3714 
3715  SmallVector<CallInst*, 16> VAStartInstrumentationList;
3716 
3717  VarArgPowerPC64Helper(Function &F, MemorySanitizer &MS,
3718  MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {}
3719 
3720  void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
3721  // For PowerPC, we need to deal with alignment of stack arguments -
3722  // they are mostly aligned to 8 bytes, but vectors and i128 arrays
3723  // are aligned to 16 bytes, byvals can be aligned to 8 or 16 bytes,
3724  // and QPX vectors are aligned to 32 bytes. For that reason, we
3725  // compute current offset from stack pointer (which is always properly
3726  // aligned), and offset for the first vararg, then subtract them.
3727  unsigned VAArgBase;
3728  Triple TargetTriple(F.getParent()->getTargetTriple());
3729  // Parameter save area starts at 48 bytes from frame pointer for ABIv1,
3730  // and 32 bytes for ABIv2. This is usually determined by target
3731  // endianness, but in theory could be overriden by function attribute.
3732  // For simplicity, we ignore it here (it'd only matter for QPX vectors).
3733  if (TargetTriple.getArch() == Triple::ppc64)
3734  VAArgBase = 48;
3735  else
3736  VAArgBase = 32;
3737  unsigned VAArgOffset = VAArgBase;
3738  const DataLayout &DL = F.getParent()->getDataLayout();
3739  for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
3740  ArgIt != End; ++ArgIt) {
3741  Value *A = *ArgIt;
3742  unsigned ArgNo = CS.getArgumentNo(ArgIt);
3743  bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams();
3744  bool IsByVal = CS.paramHasAttr(ArgNo, Attribute::ByVal);
3745  if (IsByVal) {
3746  assert(A->getType()->isPointerTy());
3747  Type *RealTy = A->getType()->getPointerElementType();
3748  uint64_t ArgSize = DL.getTypeAllocSize(RealTy);
3749  uint64_t ArgAlign = CS.getParamAlignment(ArgNo);
3750  if (ArgAlign < 8)
3751  ArgAlign = 8;
3752  VAArgOffset = alignTo(VAArgOffset, ArgAlign);
3753  if (!IsFixed) {
3754  Value *Base = getShadowPtrForVAArgument(RealTy, IRB,
3755  VAArgOffset - VAArgBase);
3756  Value *AShadowPtr, *AOriginPtr;
3757  std::tie(AShadowPtr, AOriginPtr) = MSV.getShadowOriginPtr(
3758  A, IRB, IRB.getInt8Ty(), kShadowTLSAlignment, /*isStore*/ false);
3759 
3760  IRB.CreateMemCpy(Base, kShadowTLSAlignment, AShadowPtr,
3761  kShadowTLSAlignment, ArgSize);
3762  }
3763  VAArgOffset += alignTo(ArgSize, 8);
3764  } else {
3765  Value *Base;
3766  uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
3767  uint64_t ArgAlign = 8;
3768  if (A->getType()->isArrayTy()) {
3769  // Arrays are aligned to element size, except for long double
3770  // arrays, which are aligned to 8 bytes.
3771  Type *ElementTy = A->getType()->getArrayElementType();
3772  if (!ElementTy->isPPC_FP128Ty())
3773  ArgAlign = DL.getTypeAllocSize(ElementTy);
3774  } else if (A->getType()->isVectorTy()) {
3775  // Vectors are naturally aligned.
3776  ArgAlign = DL.getTypeAllocSize(A->getType());
3777  }
3778  if (ArgAlign < 8)
3779  ArgAlign = 8;
3780  VAArgOffset = alignTo(VAArgOffset, ArgAlign);
3781  if (DL.isBigEndian()) {
3782  // Adjusting the shadow for argument with size < 8 to match the placement
3783  // of bits in big endian system
3784  if (ArgSize < 8)
3785  VAArgOffset += (8 - ArgSize);
3786  }
3787  if (!IsFixed) {
3788  Base = getShadowPtrForVAArgument(A->getType(), IRB,
3789  VAArgOffset - VAArgBase);
3790  IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment);
3791  }
3792  VAArgOffset += ArgSize;
3793  VAArgOffset = alignTo(VAArgOffset, 8);
3794  }
3795  if (IsFixed)
3796  VAArgBase = VAArgOffset;
3797  }
3798 
3799  Constant *TotalVAArgSize = ConstantInt::get(IRB.getInt64Ty(),
3800  VAArgOffset - VAArgBase);
3801  // Here using VAArgOverflowSizeTLS as VAArgSizeTLS to avoid creation of
3802  // a new class member i.e. it is the total size of all VarArgs.
3803  IRB.CreateStore(TotalVAArgSize, MS.VAArgOverflowSizeTLS);
3804  }
3805 
3806  /// \brief Compute the shadow address for a given va_arg.
3807  Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
3808  int ArgOffset) {
3809  Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
3810  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
3811  return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
3812  "_msarg");
3813  }
3814 
3815  void visitVAStartInst(VAStartInst &I) override {
3816  IRBuilder<> IRB(&I);
3817  VAStartInstrumentationList.push_back(&I);
3818  Value *VAListTag = I.getArgOperand(0);
3819  Value *ShadowPtr, *OriginPtr;
3820  unsigned Alignment = 8;
3821  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
3822  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
3823  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3824  /* size */ 8, Alignment, false);
3825  }
3826 
3827  void visitVACopyInst(VACopyInst &I) override {
3828  IRBuilder<> IRB(&I);
3829  Value *VAListTag = I.getArgOperand(0);
3830  Value *ShadowPtr, *OriginPtr;
3831  unsigned Alignment = 8;
3832  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
3833  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
3834  // Unpoison the whole __va_list_tag.
3835  // FIXME: magic ABI constants.
3836  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3837  /* size */ 8, Alignment, false);
3838  }
3839 
3840  void finalizeInstrumentation() override {
3841  assert(!VAArgSize && !VAArgTLSCopy &&
3842  "finalizeInstrumentation called twice");
3843  IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI());
3844  VAArgSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
3845  Value *CopySize = IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, 0),
3846  VAArgSize);
3847 
3848  if (!VAStartInstrumentationList.empty()) {
3849  // If there is a va_start in this function, make a backup copy of
3850  // va_arg_tls somewhere in the function entry block.
3851  VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
3852  IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize);
3853  }
3854 
3855  // Instrument va_start.
3856  // Copy va_list shadow from the backup copy of the TLS contents.
3857  for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
3858  CallInst *OrigInst = VAStartInstrumentationList[i];
3859  IRBuilder<> IRB(OrigInst->getNextNode());
3860  Value *VAListTag = OrigInst->getArgOperand(0);
3861  Value *RegSaveAreaPtrPtr =
3862  IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
3864  Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
3865  Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
3866  unsigned Alignment = 8;
3867  std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) =
3868  MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(),
3869  Alignment, /*isStore*/ true);
3870  IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment,
3871  CopySize);
3872  }
3873  }
3874 };
3875 
3876 /// \brief A no-op implementation of VarArgHelper.
3877 struct VarArgNoOpHelper : public VarArgHelper {
3878  VarArgNoOpHelper(Function &F, MemorySanitizer &MS,
3879  MemorySanitizerVisitor &MSV) {}
3880 
3881  void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {}
3882 
3883  void visitVAStartInst(VAStartInst &I) override {}
3884 
3885  void visitVACopyInst(VACopyInst &I) override {}
3886 
3887  void finalizeInstrumentation() override {}
3888 };
3889 
3890 } // end anonymous namespace
3891 
3892 static VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
3893  MemorySanitizerVisitor &Visitor) {
3894  // VarArg handling is only implemented on AMD64. False positives are possible
3895  // on other platforms.
3896  Triple TargetTriple(Func.getParent()->getTargetTriple());
3897  if (TargetTriple.getArch() == Triple::x86_64)
3898  return new VarArgAMD64Helper(Func, Msan, Visitor);
3899  else if (TargetTriple.getArch() == Triple::mips64 ||
3900  TargetTriple.getArch() == Triple::mips64el)
3901  return new VarArgMIPS64Helper(Func, Msan, Visitor);
3902  else if (TargetTriple.getArch() == Triple::aarch64)
3903  return new VarArgAArch64Helper(Func, Msan, Visitor);
3904  else if (TargetTriple.getArch() == Triple::ppc64 ||
3905  TargetTriple.getArch() == Triple::ppc64le)
3906  return new VarArgPowerPC64Helper(Func, Msan, Visitor);
3907  else
3908  return new VarArgNoOpHelper(Func, Msan, Visitor);
3909 }
3910 
3912  if (&F == MsanCtorFunction)
3913  return false;
3914  MemorySanitizerVisitor Visitor(F, *this);
3915 
3916  // Clear out readonly/readnone attributes.
3917  AttrBuilder B;
3918  B.addAttribute(Attribute::ReadOnly)
3919  .addAttribute(Attribute::ReadNone);
3921 
3922  return Visitor.runOnFunction();
3923 }
Value * CreateInBoundsGEP(Value *Ptr, ArrayRef< Value *> IdxList, const Twine &Name="")
Definition: IRBuilder.h:1339
Type * getVectorElementType() const
Definition: Type.h:368
uint64_t CallInst * C
Return a value (possibly void), from a function.
User::op_iterator arg_iterator
The type of iterator to use when looping over actual arguments at this call site. ...
Definition: CallSite.h:213
SymbolTableList< Instruction >::iterator eraseFromParent()
This method unlinks &#39;this&#39; from the containing basic block and deletes it.
Definition: Instruction.cpp:67
unsigned Log2_32_Ceil(uint32_t Value)
Return the ceil log base 2 of the specified value, 32 if the value is zero.
Definition: MathExtras.h:544
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:111
const std::string & getTargetTriple() const
Get the target triple which is a string describing the target host.
Definition: Module.h:233
static const MemoryMapParams Linux_PowerPC64_MemoryMapParams
Function * getCalledFunction() const
Return the function called, or null if this is an indirect function invocation.
Value * CreateICmp(CmpInst::Predicate P, Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1787
Value * CreateConstGEP1_32(Value *Ptr, unsigned Idx0, const Twine &Name="")
Definition: IRBuilder.h:1378
static Constant * getString(LLVMContext &Context, StringRef Initializer, bool AddNull=true)
This method constructs a CDS and initializes it with a text string.
Definition: Constants.cpp:2479
bool isAllOnesValue() const
Return true if this is the value that would be returned by getAllOnesValue.
Definition: Constants.cpp:100
raw_ostream & errs()
This returns a reference to a raw_ostream for standard error.
void addIncoming(Value *V, BasicBlock *BB)
Add an incoming value to the end of the PHI list.
This instruction extracts a struct member or array element value from an aggregate value...
Value * CreateBinOp(Instruction::BinaryOps Opc, Value *LHS, Value *RHS, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:1192
GCNRegPressure max(const GCNRegPressure &P1, const GCNRegPressure &P2)
This class represents an incoming formal argument to a Function.
Definition: Argument.h:30
static const PlatformMemoryMapParams Linux_PowerPC_MemoryMapParams
AllocaInst * CreateAlloca(Type *Ty, unsigned AddrSpace, Value *ArraySize=nullptr, const Twine &Name="")
Definition: IRBuilder.h:1238
Base class for instruction visitors.
Definition: InstVisitor.h:81
Value * getAggregateOperand()
Value * CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1681
Atomic ordering constants.
NodeTy * getNextNode()
Get the next node, or nullptr for the list tail.
Definition: ilist_node.h:289
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:115
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
BinaryOps getOpcode() const
Definition: InstrTypes.h:555
unsigned getParamAlignment(unsigned ArgNo) const
Extract the alignment for a call or parameter (0=unknown).
Definition: CallSite.h:406
bool isAtomic() const
Return true if this instruction has an AtomicOrdering of unordered or higher.
Constant * getOrInsertFunction(StringRef Name, FunctionType *T, AttributeList AttributeList)
Look up the specified function in the module symbol table.
Definition: Module.cpp:142
Value * CreateXor(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1094
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:63
bool isSized(SmallPtrSetImpl< Type *> *Visited=nullptr) const
Return true if it makes sense to take the size of this type.
Definition: Type.h:262
#define LLVM_FALLTHROUGH
LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements.
Definition: Compiler.h:235
LLVM_ATTRIBUTE_ALWAYS_INLINE size_type size() const
Definition: SmallVector.h:136
void setOrdering(AtomicOrdering Ordering)
Sets the ordering constraint of this rmw instruction.
Definition: Instructions.h:762
static const MemoryMapParams Linux_I386_MemoryMapParams
Same, but only replaced by something equivalent.
Definition: GlobalValue.h:54
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:514
static const MemoryMapParams NetBSD_X86_64_MemoryMapParams
static cl::opt< bool > ClPoisonStackWithCall("msan-poison-stack-with-call", cl::desc("poison uninitialized stack variables with a call"), cl::Hidden, cl::init(false))
This class represents zero extension of integer types.
static const unsigned kRetvalTLSSize
Value * CreateICmpSLT(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1709
This class represents a function call, abstracting a target machine&#39;s calling convention.
static PointerType * getInt32PtrTy(LLVMContext &C, unsigned AS=0)
Definition: Type.cpp:228
void setOrdering(AtomicOrdering Ordering)
Sets the ordering constraint of this load instruction.
Definition: Instructions.h:239
static PointerType * get(Type *ElementType, unsigned AddressSpace)
This constructs a pointer to an object of the specified type in a numbered address space...
Definition: Type.cpp:617
const Value * getTrueValue() const
AtomicOrdering getOrdering() const
Returns the ordering constraint of this load instruction.
Definition: Instructions.h:233
Like Internal, but omit from symbol table.
Definition: GlobalValue.h:57
static VarArgHelper * CreateVarArgHelper(Function &Func, MemorySanitizer &Msan, MemorySanitizerVisitor &Visitor)
This instruction constructs a fixed permutation of two input vectors.
static cl::opt< bool > ClWithComdat("msan-with-comdat", cl::desc("Place MSan constructors in comdat sections"), cl::Hidden, cl::init(false))
Externally visible function.
Definition: GlobalValue.h:49
bool hasFnAttribute(Attribute::AttrKind Kind) const
Return true if the function has the attribute.
Definition: Function.h:302
A raw_ostream that writes to an SmallVector or SmallString.
Definition: raw_ostream.h:494
This class wraps the llvm.memset intrinsic.
static bool isEquality(Predicate P)
Return true if this predicate is either EQ or NE.
Value * CreateSExt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1501
Metadata node.
Definition: Metadata.h:862
static unsigned TypeSizeToSizeIndex(unsigned TypeSize)
F(f)
This class represents a sign extension of integer types.
uint64_t alignTo(uint64_t Value, uint64_t Align, uint64_t Skew=0)
Returns the next integer (mod 2**64) that is greater than or equal to Value and is a multiple of Alig...
Definition: MathExtras.h:677
CallInst * CreateMemSet(Value *Ptr, Value *Val, uint64_t Size, unsigned Align, bool isVolatile=false, MDNode *TBAATag=nullptr, MDNode *ScopeTag=nullptr, MDNode *NoAliasTag=nullptr)
Create and insert a memset to the specified pointer and the specified value.
Definition: IRBuilder.h:404
An instruction for reading from memory.
Definition: Instructions.h:164
AttrBuilder & addAttribute(Attribute::AttrKind Val)
Add an attribute to the builder.
an instruction that atomically reads a memory location, combines it with another value, and then stores the result back.
Definition: Instructions.h:677
Hexagon Common GEP
bool isVectorTy() const
True if this is an instance of VectorType.
Definition: Type.h:227
#define op(i)
bool isMustTailCall() const
static Type * getX86_MMXTy(LLVMContext &C)
Definition: Type.cpp:171
static cl::opt< unsigned long long > ClXorMask("msan-xor-mask", cl::desc("Define custom MSan XorMask"), cl::Hidden, cl::init(0))
Use * op_iterator
Definition: User.h:225
bool isPPC_FP128Ty() const
Return true if this is powerpc long double.
Definition: Type.h:159
static const MemoryMapParams Linux_AArch64_MemoryMapParams
static cl::opt< bool > ClHandleICmp("msan-handle-icmp", cl::desc("propagate shadow through ICmpEQ and ICmpNE"), cl::Hidden, cl::init(true))
op_iterator op_begin()
Definition: User.h:230
static PointerType * getInt64PtrTy(LLVMContext &C, unsigned AS=0)
Definition: Type.cpp:232
static Constant * get(ArrayType *T, ArrayRef< Constant *> V)
Definition: Constants.cpp:950
unsigned getBitWidth() const
Return the number of bits in the APInt.
Definition: APInt.h:1488
bool onlyReadsMemory() const
Determine if the call does not access or only reads memory.
static Constant * getNullValue(Type *Ty)
Constructor to create a &#39;0&#39; constant of arbitrary type.
Definition: Constants.cpp:258
Value * CreateNot(Value *V, const Twine &Name="")
Definition: IRBuilder.h:1228
StoreInst * CreateAlignedStore(Value *Val, Value *Ptr, unsigned Align, bool isVolatile=false)
Definition: IRBuilder.h:1292
IntegerType * getInt32Ty()
Fetch the type representing a 32-bit integer.
Definition: IRBuilder.h:347
unsigned countTrailingZeros() const
Count the number of trailing zero bits.
Definition: APInt.h:1611
static cl::opt< int > ClPoisonStackPattern("msan-poison-stack-pattern", cl::desc("poison uninitialized stack variables with the given pattern"), cl::Hidden, cl::init(0xff))
ArrayRef< unsigned > getIndices() const
AnalysisUsage & addRequired()
#define INITIALIZE_PASS_DEPENDENCY(depName)
Definition: PassSupport.h:51
bool isSigned() const
Determine if this instruction is using a signed comparison.
Definition: InstrTypes.h:1054
static cl::opt< bool > ClDumpStrictInstructions("msan-dump-strict-instructions", cl::desc("print out instructions with default strict semantics"), cl::Hidden, cl::init(false))
This class represents the LLVM &#39;select&#39; instruction.
Type * getPointerElementType() const
Definition: Type.h:373
const DataLayout & getDataLayout() const
Get the data layout for the module&#39;s target platform.
Definition: Module.cpp:361
unsigned getAlignment() const
Return the alignment of the memory that is being allocated by the instruction.
Definition: Instructions.h:109
IntegerType * getInt64Ty()
Fetch the type representing a 64-bit integer.
Definition: IRBuilder.h:352
This is the base class for all instructions that perform data casts.
Definition: InstrTypes.h:592
ArrayRef< T > makeArrayRef(const T &OneElt)
Construct an ArrayRef from a single element.
Definition: ArrayRef.h:451
&#39;undef&#39; values are things that do not have specified contents.
Definition: Constants.h:1260
This class wraps the llvm.memmove intrinsic.
Class to represent struct types.
Definition: DerivedTypes.h:201
LLVMContext & getContext() const
Get the global data context.
Definition: Module.h:237
static cl::opt< bool > ClCheckAccessAddress("msan-check-access-address", cl::desc("report accesses through a pointer which has poisoned shadow"), cl::Hidden, cl::init(true))
PointerType * getPointerTo(unsigned AddrSpace=0) const
Return a pointer to the current type.
Definition: Type.cpp:639
IterTy arg_end() const
Definition: CallSite.h:575
bool isUnsigned() const
Determine if this instruction is using an unsigned comparison.
Definition: InstrTypes.h:1060
static cl::opt< unsigned long long > ClAndMask("msan-and-mask", cl::desc("Define custom MSan AndMask"), cl::Hidden, cl::init(0))
bool isIntegerTy() const
True if this is an instance of IntegerType.
Definition: Type.h:197
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
Definition: IRBuilder.h:677
IntegerType * getIntPtrTy(const DataLayout &DL, unsigned AddrSpace=0)
Fetch the type representing a pointer to an integer value.
Definition: IRBuilder.h:390
This file contains the simple types necessary to represent the attributes associated with functions a...
static cl::opt< unsigned long long > ClOriginBase("msan-origin-base", cl::desc("Define custom MSan OriginBase"), cl::Hidden, cl::init(0))
InstrTy * getInstruction() const
Definition: CallSite.h:92
Value * CreateAdd(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:908
void setName(const Twine &Name)
Change the name of the value.
Definition: Value.cpp:295
static cl::opt< bool > ClHandleAsmConservative("msan-handle-asm-conservative", cl::desc("conservative handling of inline assembly"), cl::Hidden, cl::init(false))
static StructType * get(LLVMContext &Context, ArrayRef< Type *> Elements, bool isPacked=false)
This static method is the primary way to create a literal StructType.
Definition: Type.cpp:336
This file implements a class to represent arbitrary precision integral constant values and operations...
Type * getVoidTy()
Fetch the type representing void.
Definition: IRBuilder.h:380
This class represents a cast from a pointer to an integer.
AtomicOrdering
Atomic ordering for LLVM&#39;s memory model.
StoreInst * CreateStore(Value *Val, Value *Ptr, bool isVolatile=false)
Definition: IRBuilder.h:1267
Value * CreateIntToPtr(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1565
ValTy * getCalledValue() const
Return the pointer to function that is being called.
Definition: CallSite.h:100
bool isNullValue() const
Return true if this is the value that would be returned by getNullValue.
Definition: Constants.cpp:85
Class to represent function types.
Definition: DerivedTypes.h:103
Value * CreateBitCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1570
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:245
This represents the llvm.va_start intrinsic.
static const char *const kMsanInitName
std::string itostr(int64_t X)
Definition: StringExtras.h:208
AtomicOrdering getSuccessOrdering() const
Returns the success ordering constraint of this cmpxchg instruction.
Definition: Instructions.h:568
#define T
static cl::opt< int > ClTrackOrigins("msan-track-origins", cl::desc("Track origins (allocation sites) of poisoned memory"), cl::Hidden, cl::init(0))
Track origins of uninitialized values.
Class to represent array types.
Definition: DerivedTypes.h:369
This instruction compares its operands according to the predicate given to the constructor.
static bool isStore(int Opcode)
bool isVarArg() const
Definition: DerivedTypes.h:123
This class represents a no-op cast from one type to another.
bool paramHasAttr(unsigned ArgNo, Attribute::AttrKind Kind) const
Return true if the call or the callee has the given attribute.
Definition: CallSite.h:377
MDNode * getMetadata(unsigned KindID) const
Get the metadata of given kind attached to this Instruction.
Definition: Instruction.h:195
Value * getInsertedValueOperand()
SmallString - A SmallString is just a SmallVector with methods and accessors that make it work better...
Definition: SmallString.h:26
Value * CreateSub(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:925
An instruction for storing to memory.
Definition: Instructions.h:306
bool removeUnreachableBlocks(Function &F, LazyValueInfo *LVI=nullptr, DeferredDominance *DDT=nullptr)
Remove all blocks that can not be reached from the function&#39;s entry.
Definition: Local.cpp:1944
bool isIntOrIntVectorTy() const
Return true if this is an integer type or a vector of integer types.
Definition: Type.h:203
static const unsigned kParamTLSSize
Value * CreateZExt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1497
static cl::opt< bool > ClPoisonStack("msan-poison-stack", cl::desc("poison uninitialized stack variables"), cl::Hidden, cl::init(true))
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:993
This class represents a truncation of integer types.
void SetInsertPoint(BasicBlock *TheBB)
This specifies that created instructions should be appended to the end of the specified block...
Definition: IRBuilder.h:127
Value * getOperand(unsigned i) const
Definition: User.h:170
static const PlatformMemoryMapParams Linux_MIPS_MemoryMapParams
bool isRelational() const
Return true if the predicate is relational (not EQ or NE).
bool isCall() const
Return true if a CallInst is enclosed.
Definition: CallSite.h:87
Value * CreateOr(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1076
static const unsigned kMinOriginAlignment
Constant * getAggregateElement(unsigned Elt) const
For aggregates (struct/array/vector) return the constant that corresponds to the specified element if...
Definition: Constants.cpp:328
bool doesNotAccessMemory() const
Determine if the call does not access memory.
Type * getScalarType() const
If this is a vector type, return the element type, otherwise return &#39;this&#39;.
Definition: Type.h:301
Value * getOperand(unsigned i_nocapture) const
bool isZeroValue() const
Return true if the value is negative zero or null value.
Definition: Constants.cpp:65
bool isVoidTy() const
Return true if this is &#39;void&#39;.
Definition: Type.h:141
const BasicBlock & getEntryBlock() const
Definition: Function.h:621
an instruction for type-safe pointer arithmetic to access elements of arrays and structs ...
Definition: Instructions.h:837
LoadInst * CreateLoad(Value *Ptr, const char *Name)
Provided to resolve &#39;CreateLoad(Ptr, "...")&#39; correctly, instead of converting the string to &#39;bool&#39; fo...
Definition: IRBuilder.h:1251
static cl::opt< unsigned long long > ClShadowBase("msan-shadow-base", cl::desc("Define custom MSan ShadowBase"), cl::Hidden, cl::init(0))
static bool runOnFunction(Function &F, bool PostInlining)
initializer< Ty > init(const Ty &Val)
Definition: CommandLine.h:406
unsigned getNumOperands() const
This instruction inserts a single (scalar) element into a VectorType value.
The landingpad instruction holds all of the information necessary to generate correct exception handl...
const Instruction * getFirstNonPHI() const
Returns a pointer to the first instruction in this block that is not a PHINode instruction.
Definition: BasicBlock.cpp:171
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
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:200
const BasicBlock * getSinglePredecessor() const
Return the predecessor of this block if it has a single predecessor block.
Definition: BasicBlock.cpp:217
INITIALIZE_PASS_BEGIN(MemorySanitizer, "msan", "MemorySanitizer: detects uninitialized reads.", false, false) INITIALIZE_PASS_END(MemorySanitizer
LLVM Basic Block Representation.
Definition: BasicBlock.h:59
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
std::pair< Function *, Function * > createSanitizerCtorAndInitFunctions(Module &M, StringRef CtorName, StringRef InitName, ArrayRef< Type *> InitArgTypes, ArrayRef< Value *> InitArgs, StringRef VersionCheckName=StringRef())
Creates sanitizer constructor function, and calls sanitizer&#39;s init function from it.
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:69
const char * getOpcodeName() const
Definition: Instruction.h:128
This is an important base class in LLVM.
Definition: Constant.h:42
Resume the propagation of an exception.
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:1842
bool isPointerTy() const
True if this is an instance of PointerType.
Definition: Type.h:221
unsigned getNumParams() const
Return the number of fixed parameters this function type requires.
Definition: DerivedTypes.h:139
Represent the analysis usage information of a pass.
op_iterator op_end()
Definition: User.h:232
static const PlatformMemoryMapParams Linux_X86_MemoryMapParams
This instruction compares its operands according to the predicate given to the constructor.
Predicate
This enumeration lists the possible predicates for CmpInst subclasses.
Definition: InstrTypes.h:885
static const unsigned End
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:285
static const unsigned kShadowTLSAlignment
static FunctionType * get(Type *Result, ArrayRef< Type *> Params, bool isVarArg)
This static method is the primary way of constructing a FunctionType.
Definition: Type.cpp:297
static Constant * get(StructType *T, ArrayRef< Constant *> V)
Definition: Constants.cpp:1011
Value * getPointerOperand()
Definition: Instructions.h:270
bool isX86_MMXTy() const
Return true if this is X86 MMX.
Definition: Type.h:182
Value * CreateICmpEQ(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1677
self_iterator getIterator()
Definition: ilist_node.h:82
Class to represent integer types.
Definition: DerivedTypes.h:40
IntegerType * getIntNTy(unsigned N)
Fetch the type representing an N-bit integer.
Definition: IRBuilder.h:360
Value * CreateExtractElement(Value *Vec, Value *Idx, const Twine &Name="")
Definition: IRBuilder.h:1862
This class represents a cast from an integer to a pointer.
const Value * getCondition() const
static Constant * getAllOnesValue(Type *Ty)
Get the all ones value.
Definition: Constants.cpp:312
static const PlatformMemoryMapParams Linux_ARM_MemoryMapParams
static const MemoryMapParams FreeBSD_X86_64_MemoryMapParams
Comdat * getOrInsertComdat(StringRef Name)
Return the Comdat in the module with the specified name.
Definition: Module.cpp:467
const Value * getArraySize() const
Get the number of elements allocated.
Definition: Instructions.h:93
Value * CreateExtractValue(Value *Agg, ArrayRef< unsigned > Idxs, const Twine &Name="")
Definition: IRBuilder.h:1904
PointerType * getInt8PtrTy(unsigned AddrSpace=0)
Fetch the type representing a pointer to an 8-bit integer value.
Definition: IRBuilder.h:385
MDNode * createBranchWeights(uint32_t TrueWeight, uint32_t FalseWeight)
Return metadata containing two branch weights.
Definition: MDBuilder.cpp:38
AtomicOrdering getOrdering() const
Returns the ordering constraint of this rmw instruction.
Definition: Instructions.h:757
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:942
Value * CreateTrunc(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1493
Type * getAllocatedType() const
Return the type that is being allocated by the instruction.
Definition: Instructions.h:102
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:44
signed greater than
Definition: InstrTypes.h:912
unsigned first
bool isInvoke() const
Return true if a InvokeInst is enclosed.
Definition: CallSite.h:90
Intrinsic::ID getIntrinsicID() const
Return the intrinsic ID of this intrinsic.
Definition: IntrinsicInst.h:51
PHINode * CreatePHI(Type *Ty, unsigned NumReservedValues, const Twine &Name="")
Definition: IRBuilder.h:1807
bool isPtrOrPtrVectorTy() const
Return true if this is a pointer type or a vector of pointer types.
Definition: Type.h:224
static IntegerType * get(LLVMContext &C, unsigned NumBits)
This static method is the primary way of constructing an IntegerType.
Definition: Type.cpp:240
Type * getSequentialElementType() const
Definition: Type.h:355
Iterator for intrusive lists based on ilist_node.
unsigned getNumOperands() const
Definition: User.h:192
See the file comment.
Definition: ValueMap.h:86
This is the shared class of boolean and integer constants.
Definition: Constants.h:84
iterator end()
Definition: BasicBlock.h:254
unsigned getScalarSizeInBits() const LLVM_READONLY
If this is a vector type, return the getPrimitiveSizeInBits value for the element type...
Definition: Type.cpp:130
CallingConv::ID getCallingConv() const
getCallingConv()/setCallingConv(CC) - These method get and set the calling convention of this functio...
Definition: Function.h:194
IterTy arg_begin() const
Definition: CallSite.h:571
Value * CreateIntCast(Value *V, Type *DestTy, bool isSigned, const Twine &Name="")
Definition: IRBuilder.h:1639
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:862
Module.h This file contains the declarations for the Module class.
Value * CreateInsertElement(Value *Vec, Value *NewElt, Value *Idx, const Twine &Name="")
Definition: IRBuilder.h:1875
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:724
bool isAggregateType() const
Return true if the type is an aggregate type.
Definition: Type.h:255
signed less than
Definition: InstrTypes.h:914
TerminatorInst * SplitBlockAndInsertIfThen(Value *Cond, Instruction *SplitBefore, bool Unreachable, MDNode *BranchWeights=nullptr, DominatorTree *DT=nullptr, LoopInfo *LI=nullptr)
Split the containing block at the specified instruction - everything before SplitBefore stays in the ...
CHAIN = SC CHAIN, Imm128 - System call.
ConstantInt * getInt32(uint32_t C)
Get a constant 32-bit value.
Definition: IRBuilder.h:307
static IntegerType * getIntNTy(LLVMContext &C, unsigned N)
Definition: Type.cpp:180
StringRef str()
Return a StringRef for the vector contents.
Definition: raw_ostream.h:519
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:422
This class wraps the llvm.memcpy intrinsic.
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:611
void appendToGlobalCtors(Module &M, Function *F, int Priority, Constant *Data=nullptr)
Append F to the list of global ctors of module M with the given Priority.
Definition: ModuleUtils.cpp:84
unsigned getNumIncomingValues() const
Return the number of incoming edges.
static const size_t kNumberOfAccessSizes
static GlobalVariable * createPrivateNonConstGlobalForString(Module &M, StringRef Str)
Create a non-const global initialized with the given string.
static cl::opt< bool > ClKeepGoing("msan-keep-going", cl::desc("keep going after reporting a UMR"), cl::Hidden, cl::init(false))
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
unsigned getVectorNumElements() const
Definition: DerivedTypes.h:462
signed less or equal
Definition: InstrTypes.h:915
Class to represent vector types.
Definition: DerivedTypes.h:393
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
Class for arbitrary precision integers.
Definition: APInt.h:69
IntegerType * getInt8Ty()
Fetch the type representing an 8-bit integer.
Definition: IRBuilder.h:337
Value * CreateShl(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:997
const Value * getFalseValue() const
Value * CreatePointerCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1616
uint64_t getTypeSizeInBits(Type *Ty) const
Size examples:
Definition: DataLayout.h:560
static cl::opt< ITMode > IT(cl::desc("IT block support"), cl::Hidden, cl::init(DefaultIT), cl::ZeroOrMore, cl::values(clEnumValN(DefaultIT, "arm-default-it", "Generate IT block based on arch"), clEnumValN(RestrictedIT, "arm-restrict-it", "Disallow deprecated IT based on ARMv8"), clEnumValN(NoRestrictedIT, "arm-no-restrict-it", "Allow IT blocks based on ARMv7")))
uint64_t getTypeAllocSize(Type *Ty) const
Returns the offset in bytes between successive objects of the specified type, including alignment pad...
Definition: DataLayout.h:428
void removeAttributes(unsigned i, const AttrBuilder &Attrs)
removes the attributes from the list of attributes.
Definition: Function.cpp:394
The C convention as implemented on Windows/x86-64 and AArch64.
Definition: CallingConv.h:154
Predicate getPredicate() const
Return the predicate for this instruction.
Definition: InstrTypes.h:959
bool isInlineAsm() const
Check if this call is an inline asm statement.
static cl::opt< bool > ClHandleICmpExact("msan-handle-icmp-exact", cl::desc("exact handling of relational integer ICmp"), cl::Hidden, cl::init(false))
unsigned getAlignment() const
Return the alignment of the access that is being performed.
Definition: Instructions.h:226
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:61
unsigned getNumArgOperands() const
Return the number of call arguments.
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:224
#define I(x, y, z)
Definition: MD5.cpp:58
static const MemoryMapParams Linux_X86_64_MemoryMapParams
static ArrayType * get(Type *ElementType, uint64_t NumElements)
This static method is the primary way to construct an ArrayType.
Definition: Type.cpp:568
LLVM_NODISCARD std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type dyn_cast(const Y &Val)
Definition: Casting.h:323
This instruction extracts a single (scalar) element from a VectorType value.
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:2447
static const PlatformMemoryMapParams NetBSD_X86_MemoryMapParams
Value * getReturnValue() const
Convenience accessor. Returns null if there is no return value.
static InlineAsm * get(FunctionType *Ty, StringRef AsmString, StringRef Constraints, bool hasSideEffects, bool isAlignStack=false, AsmDialect asmDialect=AD_ATT)
InlineAsm::get - Return the specified uniqued inline asm string.
Definition: InlineAsm.cpp:43
static cl::opt< bool > ClCheckConstantShadow("msan-check-constant-shadow", cl::desc("Insert checks for constant shadow values"), cl::Hidden, cl::init(false))
static const MemoryMapParams Linux_MIPS64_MemoryMapParams
Value * CreateAnd(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1058
Value * CreatePtrToInt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1560
static const unsigned kOriginSize
static const MemoryMapParams FreeBSD_I386_MemoryMapParams
bool isFPOrFPVectorTy() const
Return true if this is a FP type or a vector of FP.
Definition: Type.h:185
iterator_range< df_iterator< T > > depth_first(const T &G)
This represents the llvm.va_copy intrinsic.
bool isArrayAllocation() const
Return true if there is an allocation size parameter to the allocation instruction that is not 1...
size_type count(const KeyT &Val) const
Return 1 if the specified key is in the map, 0 otherwise.
Definition: ValueMap.h:158
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Value * getArgOperand(unsigned i) const
getArgOperand/setArgOperand - Return/set the i-th call argument.
LoadInst * CreateAlignedLoad(Value *Ptr, unsigned Align, const char *Name)
Provided to resolve &#39;CreateAlignedLoad(Ptr, Align, "...")&#39; correctly, instead of converting the strin...
Definition: IRBuilder.h:1274
static cl::opt< int > ClInstrumentationWithCallThreshold("msan-instrumentation-with-call-threshold", cl::desc("If the function being instrumented requires more than " "this number of checks and origin stores, use callbacks instead of " "inline checks (-1 means never use callbacks)."), cl::Hidden, cl::init(3500))
unsigned getPrimitiveSizeInBits() const LLVM_READONLY
Return the basic size of this type if it is a primitive type.
Definition: Type.cpp:115
void setSuccessOrdering(AtomicOrdering Ordering)
Sets the success ordering constraint of this cmpxchg instruction.
Definition: Instructions.h:573
ArrayRef< unsigned > getIndices() const
Module * getParent()
Get the module that this global value is contained inside of...
Definition: GlobalValue.h:565
LLVM Value Representation.
Definition: Value.h:73
uint64_t getTypeStoreSize(Type *Ty) const
Returns the maximum number of bytes that may be overwritten by storing the specified type...
Definition: DataLayout.h:411
FunctionType * getFunctionType() const
Definition: CallSite.h:320
constexpr char Size[]
Key for Kernel::Arg::Metadata::mSize.
static VectorType * get(Type *ElementType, unsigned NumElements)
This static method is the primary way to construct an VectorType.
Definition: Type.cpp:593
std::underlying_type< E >::type Mask()
Get a bitmask with 1s in all places up to the high-order bit of E&#39;s largest value.
Definition: BitmaskEnum.h:81
unsigned getArgumentNo(Value::const_user_iterator I) const
Given a value use iterator, returns the argument that corresponds to it.
Definition: CallSite.h:199
BasicBlock::iterator GetInsertPoint() const
Definition: IRBuilder.h:122
FunctionPass * createMemorySanitizerPass(int TrackOrigins=0, bool Recover=false)
Value * CreateLShr(Value *LHS, Value *RHS, const Twine &Name="", bool isExact=false)
Definition: IRBuilder.h:1018
const Value * getCalledValue() const
Get a pointer to the function that is invoked by this instruction.
static cl::opt< bool > ClPoisonUndef("msan-poison-undef", cl::desc("poison undef temps"), cl::Hidden, cl::init(true))
#define DEBUG(X)
Definition: Debug.h:118
ConstantInt * getInt8(uint8_t C)
Get a constant 8-bit value.
Definition: IRBuilder.h:297
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
Predicate getSwappedPredicate() const
For example, EQ->EQ, SLE->SGE, ULT->UGT, OEQ->OEQ, ULE->UGE, OLT->OGT, etc.
Definition: InstrTypes.h:999
static const PlatformMemoryMapParams FreeBSD_X86_MemoryMapParams
Type * getArrayElementType() const
Definition: Type.h:362
Value * CreateInsertValue(Value *Agg, Value *Val, ArrayRef< unsigned > Idxs, const Twine &Name="")
Definition: IRBuilder.h:1912
bool isBigEndian() const
Definition: DataLayout.h:222
static IntegerType * getInt8Ty(LLVMContext &C)
Definition: Type.cpp:174
static const char *const kMsanModuleCtorName
static Constant * get(ArrayRef< Constant *> V)
Definition: Constants.cpp:1046
iterator_range< arg_iterator > args()
Definition: Function.h:670
signed greater or equal
Definition: InstrTypes.h:913
bool isArrayTy() const
True if this is an instance of ArrayType.
Definition: Type.h:218
Type * getContainedType(unsigned i) const
This method is used to implement the type iterator (defined at the end of the file).
Definition: Type.h:330
A wrapper class for inspecting calls to intrinsic functions.
Definition: IntrinsicInst.h:44
const BasicBlock * getParent() const
Definition: Instruction.h:67
an instruction to allocate memory on the stack
Definition: Instructions.h:60
This instruction inserts a struct field of array element value into an aggregate value.
CallInst * CreateCall(Value *Callee, ArrayRef< Value *> Args=None, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:1812