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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 /// KernelMemorySanitizer (KMSAN) implementation.
94 ///
95 /// The major differences between KMSAN and MSan instrumentation are:
96 /// - KMSAN always tracks the origins and implies msan-keep-going=true;
97 /// - KMSAN allocates shadow and origin memory for each page separately, so
98 /// there are no explicit accesses to shadow and origin in the
99 /// instrumentation.
100 /// Shadow and origin values for a particular X-byte memory location
101 /// (X=1,2,4,8) are accessed through pointers obtained via the
102 /// __msan_metadata_ptr_for_load_X(ptr)
103 /// __msan_metadata_ptr_for_store_X(ptr)
104 /// functions. The corresponding functions check that the X-byte accesses
105 /// are possible and returns the pointers to shadow and origin memory.
106 /// Arbitrary sized accesses are handled with:
107 /// __msan_metadata_ptr_for_load_n(ptr, size)
108 /// __msan_metadata_ptr_for_store_n(ptr, size);
109 /// - TLS variables are stored in a single per-task struct. A call to a
110 /// function __msan_get_context_state() returning a pointer to that struct
111 /// is inserted into every instrumented function before the entry block;
112 /// - __msan_warning() takes a 32-bit origin parameter;
113 /// - local variables are poisoned with __msan_poison_alloca() upon function
114 /// entry and unpoisoned with __msan_unpoison_alloca() before leaving the
115 /// function;
116 /// - the pass doesn't declare any global variables or add global constructors
117 /// to the translation unit.
118 ///
119 /// Also, KMSAN currently ignores uninitialized memory passed into inline asm
120 /// calls, making sure we're on the safe side wrt. possible false positives.
121 ///
122 /// KernelMemorySanitizer only supports X86_64 at the moment.
123 ///
124 //===----------------------------------------------------------------------===//
125 
126 #include "llvm/ADT/APInt.h"
127 #include "llvm/ADT/ArrayRef.h"
129 #include "llvm/ADT/SmallString.h"
130 #include "llvm/ADT/SmallVector.h"
131 #include "llvm/ADT/StringExtras.h"
132 #include "llvm/ADT/StringRef.h"
133 #include "llvm/ADT/Triple.h"
136 #include "llvm/IR/Argument.h"
137 #include "llvm/IR/Attributes.h"
138 #include "llvm/IR/BasicBlock.h"
139 #include "llvm/IR/CallSite.h"
140 #include "llvm/IR/CallingConv.h"
141 #include "llvm/IR/Constant.h"
142 #include "llvm/IR/Constants.h"
143 #include "llvm/IR/DataLayout.h"
144 #include "llvm/IR/DerivedTypes.h"
145 #include "llvm/IR/Function.h"
146 #include "llvm/IR/GlobalValue.h"
147 #include "llvm/IR/GlobalVariable.h"
148 #include "llvm/IR/IRBuilder.h"
149 #include "llvm/IR/InlineAsm.h"
150 #include "llvm/IR/InstVisitor.h"
151 #include "llvm/IR/InstrTypes.h"
152 #include "llvm/IR/Instruction.h"
153 #include "llvm/IR/Instructions.h"
154 #include "llvm/IR/IntrinsicInst.h"
155 #include "llvm/IR/Intrinsics.h"
156 #include "llvm/IR/LLVMContext.h"
157 #include "llvm/IR/MDBuilder.h"
158 #include "llvm/IR/Module.h"
159 #include "llvm/IR/Type.h"
160 #include "llvm/IR/Value.h"
161 #include "llvm/IR/ValueMap.h"
162 #include "llvm/Pass.h"
164 #include "llvm/Support/Casting.h"
166 #include "llvm/Support/Compiler.h"
167 #include "llvm/Support/Debug.h"
169 #include "llvm/Support/MathExtras.h"
174 #include <algorithm>
175 #include <cassert>
176 #include <cstddef>
177 #include <cstdint>
178 #include <memory>
179 #include <string>
180 #include <tuple>
181 
182 using namespace llvm;
183 
184 #define DEBUG_TYPE "msan"
185 
186 static const unsigned kOriginSize = 4;
187 static const unsigned kMinOriginAlignment = 4;
188 static const unsigned kShadowTLSAlignment = 8;
189 
190 // These constants must be kept in sync with the ones in msan.h.
191 static const unsigned kParamTLSSize = 800;
192 static const unsigned kRetvalTLSSize = 800;
193 
194 // Accesses sizes are powers of two: 1, 2, 4, 8.
195 static const size_t kNumberOfAccessSizes = 4;
196 
197 /// Track origins of uninitialized values.
198 ///
199 /// Adds a section to MemorySanitizer report that points to the allocation
200 /// (stack or heap) the uninitialized bits came from originally.
201 static cl::opt<int> ClTrackOrigins("msan-track-origins",
202  cl::desc("Track origins (allocation sites) of poisoned memory"),
203  cl::Hidden, cl::init(0));
204 
205 static cl::opt<bool> ClKeepGoing("msan-keep-going",
206  cl::desc("keep going after reporting a UMR"),
207  cl::Hidden, cl::init(false));
208 
209 static cl::opt<bool> ClPoisonStack("msan-poison-stack",
210  cl::desc("poison uninitialized stack variables"),
211  cl::Hidden, cl::init(true));
212 
213 static cl::opt<bool> ClPoisonStackWithCall("msan-poison-stack-with-call",
214  cl::desc("poison uninitialized stack variables with a call"),
215  cl::Hidden, cl::init(false));
216 
217 static cl::opt<int> ClPoisonStackPattern("msan-poison-stack-pattern",
218  cl::desc("poison uninitialized stack variables with the given pattern"),
219  cl::Hidden, cl::init(0xff));
220 
221 static cl::opt<bool> ClPoisonUndef("msan-poison-undef",
222  cl::desc("poison undef temps"),
223  cl::Hidden, cl::init(true));
224 
225 static cl::opt<bool> ClHandleICmp("msan-handle-icmp",
226  cl::desc("propagate shadow through ICmpEQ and ICmpNE"),
227  cl::Hidden, cl::init(true));
228 
229 static cl::opt<bool> ClHandleICmpExact("msan-handle-icmp-exact",
230  cl::desc("exact handling of relational integer ICmp"),
231  cl::Hidden, cl::init(false));
232 
233 // When compiling the Linux kernel, we sometimes see false positives related to
234 // MSan being unable to understand that inline assembly calls may initialize
235 // local variables.
236 // This flag makes the compiler conservatively unpoison every memory location
237 // passed into an assembly call. Note that this may cause false positives.
238 // Because it's impossible to figure out the array sizes, we can only unpoison
239 // the first sizeof(type) bytes for each type* pointer.
241  "msan-handle-asm-conservative",
242  cl::desc("conservative handling of inline assembly"), cl::Hidden,
243  cl::init(false));
244 
245 // This flag controls whether we check the shadow of the address
246 // operand of load or store. Such bugs are very rare, since load from
247 // a garbage address typically results in SEGV, but still happen
248 // (e.g. only lower bits of address are garbage, or the access happens
249 // early at program startup where malloc-ed memory is more likely to
250 // be zeroed. As of 2012-08-28 this flag adds 20% slowdown.
251 static cl::opt<bool> ClCheckAccessAddress("msan-check-access-address",
252  cl::desc("report accesses through a pointer which has poisoned shadow"),
253  cl::Hidden, cl::init(true));
254 
255 static cl::opt<bool> ClDumpStrictInstructions("msan-dump-strict-instructions",
256  cl::desc("print out instructions with default strict semantics"),
257  cl::Hidden, cl::init(false));
258 
260  "msan-instrumentation-with-call-threshold",
261  cl::desc(
262  "If the function being instrumented requires more than "
263  "this number of checks and origin stores, use callbacks instead of "
264  "inline checks (-1 means never use callbacks)."),
265  cl::Hidden, cl::init(3500));
266 
267 static cl::opt<bool>
268  ClEnableKmsan("msan-kernel",
269  cl::desc("Enable KernelMemorySanitizer instrumentation"),
270  cl::Hidden, cl::init(false));
271 
272 // This is an experiment to enable handling of cases where shadow is a non-zero
273 // compile-time constant. For some unexplainable reason they were silently
274 // ignored in the instrumentation.
275 static cl::opt<bool> ClCheckConstantShadow("msan-check-constant-shadow",
276  cl::desc("Insert checks for constant shadow values"),
277  cl::Hidden, cl::init(false));
278 
279 // This is off by default because of a bug in gold:
280 // https://sourceware.org/bugzilla/show_bug.cgi?id=19002
281 static cl::opt<bool> ClWithComdat("msan-with-comdat",
282  cl::desc("Place MSan constructors in comdat sections"),
283  cl::Hidden, cl::init(false));
284 
285 // These options allow to specify custom memory map parameters
286 // See MemoryMapParams for details.
287 static cl::opt<unsigned long long> ClAndMask("msan-and-mask",
288  cl::desc("Define custom MSan AndMask"),
289  cl::Hidden, cl::init(0));
290 
291 static cl::opt<unsigned long long> ClXorMask("msan-xor-mask",
292  cl::desc("Define custom MSan XorMask"),
293  cl::Hidden, cl::init(0));
294 
295 static cl::opt<unsigned long long> ClShadowBase("msan-shadow-base",
296  cl::desc("Define custom MSan ShadowBase"),
297  cl::Hidden, cl::init(0));
298 
299 static cl::opt<unsigned long long> ClOriginBase("msan-origin-base",
300  cl::desc("Define custom MSan OriginBase"),
301  cl::Hidden, cl::init(0));
302 
303 static const char *const kMsanModuleCtorName = "msan.module_ctor";
304 static const char *const kMsanInitName = "__msan_init";
305 
306 namespace {
307 
308 // Memory map parameters used in application-to-shadow address calculation.
309 // Offset = (Addr & ~AndMask) ^ XorMask
310 // Shadow = ShadowBase + Offset
311 // Origin = OriginBase + Offset
312 struct MemoryMapParams {
313  uint64_t AndMask;
314  uint64_t XorMask;
315  uint64_t ShadowBase;
316  uint64_t OriginBase;
317 };
318 
319 struct PlatformMemoryMapParams {
320  const MemoryMapParams *bits32;
321  const MemoryMapParams *bits64;
322 };
323 
324 } // end anonymous namespace
325 
326 // i386 Linux
327 static const MemoryMapParams Linux_I386_MemoryMapParams = {
328  0x000080000000, // AndMask
329  0, // XorMask (not used)
330  0, // ShadowBase (not used)
331  0x000040000000, // OriginBase
332 };
333 
334 // x86_64 Linux
335 static const MemoryMapParams Linux_X86_64_MemoryMapParams = {
336 #ifdef MSAN_LINUX_X86_64_OLD_MAPPING
337  0x400000000000, // AndMask
338  0, // XorMask (not used)
339  0, // ShadowBase (not used)
340  0x200000000000, // OriginBase
341 #else
342  0, // AndMask (not used)
343  0x500000000000, // XorMask
344  0, // ShadowBase (not used)
345  0x100000000000, // OriginBase
346 #endif
347 };
348 
349 // mips64 Linux
350 static const MemoryMapParams Linux_MIPS64_MemoryMapParams = {
351  0, // AndMask (not used)
352  0x008000000000, // XorMask
353  0, // ShadowBase (not used)
354  0x002000000000, // OriginBase
355 };
356 
357 // ppc64 Linux
358 static const MemoryMapParams Linux_PowerPC64_MemoryMapParams = {
359  0xE00000000000, // AndMask
360  0x100000000000, // XorMask
361  0x080000000000, // ShadowBase
362  0x1C0000000000, // OriginBase
363 };
364 
365 // aarch64 Linux
366 static const MemoryMapParams Linux_AArch64_MemoryMapParams = {
367  0, // AndMask (not used)
368  0x06000000000, // XorMask
369  0, // ShadowBase (not used)
370  0x01000000000, // OriginBase
371 };
372 
373 // i386 FreeBSD
374 static const MemoryMapParams FreeBSD_I386_MemoryMapParams = {
375  0x000180000000, // AndMask
376  0x000040000000, // XorMask
377  0x000020000000, // ShadowBase
378  0x000700000000, // OriginBase
379 };
380 
381 // x86_64 FreeBSD
382 static const MemoryMapParams FreeBSD_X86_64_MemoryMapParams = {
383  0xc00000000000, // AndMask
384  0x200000000000, // XorMask
385  0x100000000000, // ShadowBase
386  0x380000000000, // OriginBase
387 };
388 
389 // x86_64 NetBSD
390 static const MemoryMapParams NetBSD_X86_64_MemoryMapParams = {
391  0, // AndMask
392  0x500000000000, // XorMask
393  0, // ShadowBase
394  0x100000000000, // OriginBase
395 };
396 
397 static const PlatformMemoryMapParams Linux_X86_MemoryMapParams = {
400 };
401 
402 static const PlatformMemoryMapParams Linux_MIPS_MemoryMapParams = {
403  nullptr,
405 };
406 
407 static const PlatformMemoryMapParams Linux_PowerPC_MemoryMapParams = {
408  nullptr,
410 };
411 
412 static const PlatformMemoryMapParams Linux_ARM_MemoryMapParams = {
413  nullptr,
415 };
416 
417 static const PlatformMemoryMapParams FreeBSD_X86_MemoryMapParams = {
420 };
421 
422 static const PlatformMemoryMapParams NetBSD_X86_MemoryMapParams = {
423  nullptr,
425 };
426 
427 namespace {
428 
429 /// An instrumentation pass implementing detection of uninitialized
430 /// reads.
431 ///
432 /// MemorySanitizer: instrument the code in module to find
433 /// uninitialized reads.
434 class MemorySanitizer : public FunctionPass {
435 public:
436  // Pass identification, replacement for typeid.
437  static char ID;
438 
439  MemorySanitizer(int TrackOrigins = 0, bool Recover = false,
440  bool EnableKmsan = false)
441  : FunctionPass(ID) {
442  this->CompileKernel =
443  ClEnableKmsan.getNumOccurrences() > 0 ? ClEnableKmsan : EnableKmsan;
444  if (ClTrackOrigins.getNumOccurrences() > 0)
445  this->TrackOrigins = ClTrackOrigins;
446  else
447  this->TrackOrigins = this->CompileKernel ? 2 : TrackOrigins;
448  this->Recover = ClKeepGoing.getNumOccurrences() > 0
449  ? ClKeepGoing
450  : (this->CompileKernel | Recover);
451  }
452  StringRef getPassName() const override { return "MemorySanitizer"; }
453 
454  void getAnalysisUsage(AnalysisUsage &AU) const override {
456  }
457 
458  bool runOnFunction(Function &F) override;
459  bool doInitialization(Module &M) override;
460 
461 private:
462  friend struct MemorySanitizerVisitor;
463  friend struct VarArgAMD64Helper;
464  friend struct VarArgMIPS64Helper;
465  friend struct VarArgAArch64Helper;
466  friend struct VarArgPowerPC64Helper;
467 
468  void initializeCallbacks(Module &M);
469  void createKernelApi(Module &M);
470  void createUserspaceApi(Module &M);
471 
472  /// True if we're compiling the Linux kernel.
473  bool CompileKernel;
474 
475  /// Track origins (allocation points) of uninitialized values.
476  int TrackOrigins;
477  bool Recover;
478 
479  LLVMContext *C;
480  Type *IntptrTy;
481  Type *OriginTy;
482 
483  // XxxTLS variables represent the per-thread state in MSan and per-task state
484  // in KMSAN.
485  // For the userspace these point to thread-local globals. In the kernel land
486  // they point to the members of a per-task struct obtained via a call to
487  // __msan_get_context_state().
488 
489  /// Thread-local shadow storage for function parameters.
490  Value *ParamTLS;
491 
492  /// Thread-local origin storage for function parameters.
493  Value *ParamOriginTLS;
494 
495  /// Thread-local shadow storage for function return value.
496  Value *RetvalTLS;
497 
498  /// Thread-local origin storage for function return value.
499  Value *RetvalOriginTLS;
500 
501  /// Thread-local shadow storage for in-register va_arg function
502  /// parameters (x86_64-specific).
503  Value *VAArgTLS;
504 
505  /// Thread-local shadow storage for in-register va_arg function
506  /// parameters (x86_64-specific).
507  Value *VAArgOriginTLS;
508 
509  /// Thread-local shadow storage for va_arg overflow area
510  /// (x86_64-specific).
511  Value *VAArgOverflowSizeTLS;
512 
513  /// Thread-local space used to pass origin value to the UMR reporting
514  /// function.
515  Value *OriginTLS;
516 
517  /// Are the instrumentation callbacks set up?
518  bool CallbacksInitialized = false;
519 
520  /// The run-time callback to print a warning.
521  Value *WarningFn;
522 
523  // These arrays are indexed by log2(AccessSize).
524  Value *MaybeWarningFn[kNumberOfAccessSizes];
525  Value *MaybeStoreOriginFn[kNumberOfAccessSizes];
526 
527  /// Run-time helper that generates a new origin value for a stack
528  /// allocation.
529  Value *MsanSetAllocaOrigin4Fn;
530 
531  /// Run-time helper that poisons stack on function entry.
532  Value *MsanPoisonStackFn;
533 
534  /// Run-time helper that records a store (or any event) of an
535  /// uninitialized value and returns an updated origin id encoding this info.
536  Value *MsanChainOriginFn;
537 
538  /// MSan runtime replacements for memmove, memcpy and memset.
539  Value *MemmoveFn, *MemcpyFn, *MemsetFn;
540 
541  /// KMSAN callback for task-local function argument shadow.
542  Value *MsanGetContextStateFn;
543 
544  /// Functions for poisoning/unpoisoning local variables
545  Value *MsanPoisonAllocaFn, *MsanUnpoisonAllocaFn;
546 
547  /// Each of the MsanMetadataPtrXxx functions returns a pair of shadow/origin
548  /// pointers.
549  Value *MsanMetadataPtrForLoadN, *MsanMetadataPtrForStoreN;
550  Value *MsanMetadataPtrForLoad_1_8[4];
551  Value *MsanMetadataPtrForStore_1_8[4];
552 
553  /// Helper to choose between different MsanMetadataPtrXxx().
554  Value *getKmsanShadowOriginAccessFn(bool isStore, int size);
555 
556  /// Memory map parameters used in application-to-shadow calculation.
557  const MemoryMapParams *MapParams;
558 
559  /// Custom memory map parameters used when -msan-shadow-base or
560  // -msan-origin-base is provided.
561  MemoryMapParams CustomMapParams;
562 
563  MDNode *ColdCallWeights;
564 
565  /// Branch weights for origin store.
566  MDNode *OriginStoreWeights;
567 
568  /// An empty volatile inline asm that prevents callback merge.
569  InlineAsm *EmptyAsm;
570 
571  Function *MsanCtorFunction;
572 };
573 
574 } // end anonymous namespace
575 
576 char MemorySanitizer::ID = 0;
577 
579  MemorySanitizer, "msan",
580  "MemorySanitizer: detects uninitialized reads.", false, false)
583  MemorySanitizer, "msan",
584  "MemorySanitizer: detects uninitialized reads.", false, false)
585 
586 FunctionPass *llvm::createMemorySanitizerPass(int TrackOrigins, bool Recover,
587  bool CompileKernel) {
588  return new MemorySanitizer(TrackOrigins, Recover, CompileKernel);
589 }
590 
591 /// Create a non-const global initialized with the given string.
592 ///
593 /// Creates a writable global for Str so that we can pass it to the
594 /// run-time lib. Runtime uses first 4 bytes of the string to store the
595 /// frame ID, so the string needs to be mutable.
597  StringRef Str) {
598  Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
599  return new GlobalVariable(M, StrConst->getType(), /*isConstant=*/false,
600  GlobalValue::PrivateLinkage, StrConst, "");
601 }
602 
603 /// Create KMSAN API callbacks.
604 void MemorySanitizer::createKernelApi(Module &M) {
605  IRBuilder<> IRB(*C);
606 
607  // These will be initialized in insertKmsanPrologue().
608  RetvalTLS = nullptr;
609  RetvalOriginTLS = nullptr;
610  ParamTLS = nullptr;
611  ParamOriginTLS = nullptr;
612  VAArgTLS = nullptr;
613  VAArgOriginTLS = nullptr;
614  VAArgOverflowSizeTLS = nullptr;
615  // OriginTLS is unused in the kernel.
616  OriginTLS = nullptr;
617 
618  // __msan_warning() in the kernel takes an origin.
619  WarningFn = M.getOrInsertFunction("__msan_warning", IRB.getVoidTy(),
620  IRB.getInt32Ty());
621  // Requests the per-task context state (kmsan_context_state*) from the
622  // runtime library.
623  MsanGetContextStateFn = M.getOrInsertFunction(
624  "__msan_get_context_state",
626  StructType::get(ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8),
627  ArrayType::get(IRB.getInt64Ty(), kRetvalTLSSize / 8),
628  ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8),
630  kParamTLSSize / 8), /* va_arg_origin */
631  IRB.getInt64Ty(),
632  ArrayType::get(OriginTy, kParamTLSSize / 4), OriginTy,
633  OriginTy),
634  0));
635 
636  Type *RetTy = StructType::get(PointerType::get(IRB.getInt8Ty(), 0),
637  PointerType::get(IRB.getInt32Ty(), 0));
638 
639  for (int ind = 0, size = 1; ind < 4; ind++, size <<= 1) {
640  std::string name_load =
641  "__msan_metadata_ptr_for_load_" + std::to_string(size);
642  std::string name_store =
643  "__msan_metadata_ptr_for_store_" + std::to_string(size);
644  MsanMetadataPtrForLoad_1_8[ind] = M.getOrInsertFunction(
645  name_load, RetTy, PointerType::get(IRB.getInt8Ty(), 0));
646  MsanMetadataPtrForStore_1_8[ind] = M.getOrInsertFunction(
647  name_store, RetTy, PointerType::get(IRB.getInt8Ty(), 0));
648  }
649 
650  MsanMetadataPtrForLoadN = M.getOrInsertFunction(
651  "__msan_metadata_ptr_for_load_n", RetTy,
652  PointerType::get(IRB.getInt8Ty(), 0), IRB.getInt64Ty());
653  MsanMetadataPtrForStoreN = M.getOrInsertFunction(
654  "__msan_metadata_ptr_for_store_n", RetTy,
655  PointerType::get(IRB.getInt8Ty(), 0), IRB.getInt64Ty());
656 
657  // Functions for poisoning and unpoisoning memory.
658  MsanPoisonAllocaFn =
659  M.getOrInsertFunction("__msan_poison_alloca", IRB.getVoidTy(),
660  IRB.getInt8PtrTy(), IntptrTy, IRB.getInt8PtrTy());
661  MsanUnpoisonAllocaFn = M.getOrInsertFunction(
662  "__msan_unpoison_alloca", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy);
663 }
664 
665 /// Insert declarations for userspace-specific functions and globals.
666 void MemorySanitizer::createUserspaceApi(Module &M) {
667  IRBuilder<> IRB(*C);
668  // Create the callback.
669  // FIXME: this function should have "Cold" calling conv,
670  // which is not yet implemented.
671  StringRef WarningFnName = Recover ? "__msan_warning"
672  : "__msan_warning_noreturn";
673  WarningFn = M.getOrInsertFunction(WarningFnName, IRB.getVoidTy());
674 
675  // Create the global TLS variables.
676  RetvalTLS = new GlobalVariable(
677  M, ArrayType::get(IRB.getInt64Ty(), kRetvalTLSSize / 8), false,
678  GlobalVariable::ExternalLinkage, nullptr, "__msan_retval_tls", nullptr,
680 
681  RetvalOriginTLS = new GlobalVariable(
682  M, OriginTy, false, GlobalVariable::ExternalLinkage, nullptr,
683  "__msan_retval_origin_tls", nullptr, GlobalVariable::InitialExecTLSModel);
684 
685  ParamTLS = new GlobalVariable(
686  M, ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), false,
687  GlobalVariable::ExternalLinkage, nullptr, "__msan_param_tls", nullptr,
689 
690  ParamOriginTLS = new GlobalVariable(
691  M, ArrayType::get(OriginTy, kParamTLSSize / 4), false,
692  GlobalVariable::ExternalLinkage, nullptr, "__msan_param_origin_tls",
694 
695  VAArgTLS = new GlobalVariable(
696  M, ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), false,
697  GlobalVariable::ExternalLinkage, nullptr, "__msan_va_arg_tls", nullptr,
699 
700  VAArgOriginTLS = new GlobalVariable(
701  M, ArrayType::get(OriginTy, kParamTLSSize / 4), false,
702  GlobalVariable::ExternalLinkage, nullptr, "__msan_va_arg_origin_tls",
704 
705  VAArgOverflowSizeTLS = new GlobalVariable(
706  M, IRB.getInt64Ty(), false, GlobalVariable::ExternalLinkage, nullptr,
707  "__msan_va_arg_overflow_size_tls", nullptr,
709  OriginTLS = new GlobalVariable(
710  M, IRB.getInt32Ty(), false, GlobalVariable::ExternalLinkage, nullptr,
711  "__msan_origin_tls", nullptr, GlobalVariable::InitialExecTLSModel);
712 
713  for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
714  AccessSizeIndex++) {
715  unsigned AccessSize = 1 << AccessSizeIndex;
716  std::string FunctionName = "__msan_maybe_warning_" + itostr(AccessSize);
717  MaybeWarningFn[AccessSizeIndex] = M.getOrInsertFunction(
718  FunctionName, IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8),
719  IRB.getInt32Ty());
720 
721  FunctionName = "__msan_maybe_store_origin_" + itostr(AccessSize);
722  MaybeStoreOriginFn[AccessSizeIndex] = M.getOrInsertFunction(
723  FunctionName, IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8),
724  IRB.getInt8PtrTy(), IRB.getInt32Ty());
725  }
726 
727  MsanSetAllocaOrigin4Fn = M.getOrInsertFunction(
728  "__msan_set_alloca_origin4", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy,
729  IRB.getInt8PtrTy(), IntptrTy);
730  MsanPoisonStackFn =
731  M.getOrInsertFunction("__msan_poison_stack", IRB.getVoidTy(),
732  IRB.getInt8PtrTy(), IntptrTy);
733 }
734 
735 /// Insert extern declaration of runtime-provided functions and globals.
736 void MemorySanitizer::initializeCallbacks(Module &M) {
737  // Only do this once.
738  if (CallbacksInitialized)
739  return;
740 
741  IRBuilder<> IRB(*C);
742  // Initialize callbacks that are common for kernel and userspace
743  // instrumentation.
744  MsanChainOriginFn = M.getOrInsertFunction(
745  "__msan_chain_origin", IRB.getInt32Ty(), IRB.getInt32Ty());
746  MemmoveFn = M.getOrInsertFunction(
747  "__msan_memmove", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
748  IRB.getInt8PtrTy(), IntptrTy);
749  MemcpyFn = M.getOrInsertFunction(
750  "__msan_memcpy", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
751  IntptrTy);
752  MemsetFn = M.getOrInsertFunction(
753  "__msan_memset", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt32Ty(),
754  IntptrTy);
755  // We insert an empty inline asm after __msan_report* to avoid callback merge.
756  EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
757  StringRef(""), StringRef(""),
758  /*hasSideEffects=*/true);
759 
760  if (CompileKernel) {
761  createKernelApi(M);
762  } else {
763  createUserspaceApi(M);
764  }
765  CallbacksInitialized = true;
766 }
767 
768 Value *MemorySanitizer::getKmsanShadowOriginAccessFn(bool isStore, int size) {
769  Value **Fns =
770  isStore ? MsanMetadataPtrForStore_1_8 : MsanMetadataPtrForLoad_1_8;
771  switch (size) {
772  case 1:
773  return Fns[0];
774  case 2:
775  return Fns[1];
776  case 4:
777  return Fns[2];
778  case 8:
779  return Fns[3];
780  default:
781  return nullptr;
782  }
783 }
784 
785 /// Module-level initialization.
786 ///
787 /// inserts a call to __msan_init to the module's constructor list.
788 bool MemorySanitizer::doInitialization(Module &M) {
789  auto &DL = M.getDataLayout();
790 
791  bool ShadowPassed = ClShadowBase.getNumOccurrences() > 0;
792  bool OriginPassed = ClOriginBase.getNumOccurrences() > 0;
793  // Check the overrides first
794  if (ShadowPassed || OriginPassed) {
795  CustomMapParams.AndMask = ClAndMask;
796  CustomMapParams.XorMask = ClXorMask;
797  CustomMapParams.ShadowBase = ClShadowBase;
798  CustomMapParams.OriginBase = ClOriginBase;
799  MapParams = &CustomMapParams;
800  } else {
801  Triple TargetTriple(M.getTargetTriple());
802  switch (TargetTriple.getOS()) {
803  case Triple::FreeBSD:
804  switch (TargetTriple.getArch()) {
805  case Triple::x86_64:
806  MapParams = FreeBSD_X86_MemoryMapParams.bits64;
807  break;
808  case Triple::x86:
809  MapParams = FreeBSD_X86_MemoryMapParams.bits32;
810  break;
811  default:
812  report_fatal_error("unsupported architecture");
813  }
814  break;
815  case Triple::NetBSD:
816  switch (TargetTriple.getArch()) {
817  case Triple::x86_64:
818  MapParams = NetBSD_X86_MemoryMapParams.bits64;
819  break;
820  default:
821  report_fatal_error("unsupported architecture");
822  }
823  break;
824  case Triple::Linux:
825  switch (TargetTriple.getArch()) {
826  case Triple::x86_64:
827  MapParams = Linux_X86_MemoryMapParams.bits64;
828  break;
829  case Triple::x86:
830  MapParams = Linux_X86_MemoryMapParams.bits32;
831  break;
832  case Triple::mips64:
833  case Triple::mips64el:
834  MapParams = Linux_MIPS_MemoryMapParams.bits64;
835  break;
836  case Triple::ppc64:
837  case Triple::ppc64le:
838  MapParams = Linux_PowerPC_MemoryMapParams.bits64;
839  break;
840  case Triple::aarch64:
841  case Triple::aarch64_be:
842  MapParams = Linux_ARM_MemoryMapParams.bits64;
843  break;
844  default:
845  report_fatal_error("unsupported architecture");
846  }
847  break;
848  default:
849  report_fatal_error("unsupported operating system");
850  }
851  }
852 
853  C = &(M.getContext());
854  IRBuilder<> IRB(*C);
855  IntptrTy = IRB.getIntPtrTy(DL);
856  OriginTy = IRB.getInt32Ty();
857 
858  ColdCallWeights = MDBuilder(*C).createBranchWeights(1, 1000);
859  OriginStoreWeights = MDBuilder(*C).createBranchWeights(1, 1000);
860 
861  if (!CompileKernel) {
862  std::tie(MsanCtorFunction, std::ignore) =
865  /*InitArgTypes=*/{},
866  /*InitArgs=*/{});
867  if (ClWithComdat) {
868  Comdat *MsanCtorComdat = M.getOrInsertComdat(kMsanModuleCtorName);
869  MsanCtorFunction->setComdat(MsanCtorComdat);
870  appendToGlobalCtors(M, MsanCtorFunction, 0, MsanCtorFunction);
871  } else {
872  appendToGlobalCtors(M, MsanCtorFunction, 0);
873  }
874 
875  if (TrackOrigins)
877  IRB.getInt32(TrackOrigins), "__msan_track_origins");
878 
879  if (Recover)
881  IRB.getInt32(Recover), "__msan_keep_going");
882  }
883  return true;
884 }
885 
886 namespace {
887 
888 /// A helper class that handles instrumentation of VarArg
889 /// functions on a particular platform.
890 ///
891 /// Implementations are expected to insert the instrumentation
892 /// necessary to propagate argument shadow through VarArg function
893 /// calls. Visit* methods are called during an InstVisitor pass over
894 /// the function, and should avoid creating new basic blocks. A new
895 /// instance of this class is created for each instrumented function.
896 struct VarArgHelper {
897  virtual ~VarArgHelper() = default;
898 
899  /// Visit a CallSite.
900  virtual void visitCallSite(CallSite &CS, IRBuilder<> &IRB) = 0;
901 
902  /// Visit a va_start call.
903  virtual void visitVAStartInst(VAStartInst &I) = 0;
904 
905  /// Visit a va_copy call.
906  virtual void visitVACopyInst(VACopyInst &I) = 0;
907 
908  /// Finalize function instrumentation.
909  ///
910  /// This method is called after visiting all interesting (see above)
911  /// instructions in a function.
912  virtual void finalizeInstrumentation() = 0;
913 };
914 
915 struct MemorySanitizerVisitor;
916 
917 } // end anonymous namespace
918 
919 static VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
920  MemorySanitizerVisitor &Visitor);
921 
922 static unsigned TypeSizeToSizeIndex(unsigned TypeSize) {
923  if (TypeSize <= 8) return 0;
924  return Log2_32_Ceil((TypeSize + 7) / 8);
925 }
926 
927 namespace {
928 
929 /// This class does all the work for a given function. Store and Load
930 /// instructions store and load corresponding shadow and origin
931 /// values. Most instructions propagate shadow from arguments to their
932 /// return values. Certain instructions (most importantly, BranchInst)
933 /// test their argument shadow and print reports (with a runtime call) if it's
934 /// non-zero.
935 struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
936  Function &F;
937  MemorySanitizer &MS;
938  SmallVector<PHINode *, 16> ShadowPHINodes, OriginPHINodes;
939  ValueMap<Value*, Value*> ShadowMap, OriginMap;
940  std::unique_ptr<VarArgHelper> VAHelper;
941  const TargetLibraryInfo *TLI;
942  BasicBlock *ActualFnStart;
943 
944  // The following flags disable parts of MSan instrumentation based on
945  // blacklist contents and command-line options.
946  bool InsertChecks;
947  bool PropagateShadow;
948  bool PoisonStack;
949  bool PoisonUndef;
950  bool CheckReturnValue;
951 
952  struct ShadowOriginAndInsertPoint {
953  Value *Shadow;
954  Value *Origin;
955  Instruction *OrigIns;
956 
957  ShadowOriginAndInsertPoint(Value *S, Value *O, Instruction *I)
958  : Shadow(S), Origin(O), OrigIns(I) {}
959  };
962 
963  MemorySanitizerVisitor(Function &F, MemorySanitizer &MS)
964  : F(F), MS(MS), VAHelper(CreateVarArgHelper(F, MS, *this)) {
965  bool SanitizeFunction = F.hasFnAttribute(Attribute::SanitizeMemory);
966  InsertChecks = SanitizeFunction;
967  PropagateShadow = SanitizeFunction;
968  PoisonStack = SanitizeFunction && ClPoisonStack;
969  PoisonUndef = SanitizeFunction && ClPoisonUndef;
970  // FIXME: Consider using SpecialCaseList to specify a list of functions that
971  // must always return fully initialized values. For now, we hardcode "main".
972  CheckReturnValue = SanitizeFunction && (F.getName() == "main");
973  TLI = &MS.getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
974 
975  MS.initializeCallbacks(*F.getParent());
976  if (MS.CompileKernel)
977  ActualFnStart = insertKmsanPrologue(F);
978  else
979  ActualFnStart = &F.getEntryBlock();
980 
981  LLVM_DEBUG(if (!InsertChecks) dbgs()
982  << "MemorySanitizer is not inserting checks into '"
983  << F.getName() << "'\n");
984  }
985 
986  Value *updateOrigin(Value *V, IRBuilder<> &IRB) {
987  if (MS.TrackOrigins <= 1) return V;
988  return IRB.CreateCall(MS.MsanChainOriginFn, V);
989  }
990 
991  Value *originToIntptr(IRBuilder<> &IRB, Value *Origin) {
992  const DataLayout &DL = F.getParent()->getDataLayout();
993  unsigned IntptrSize = DL.getTypeStoreSize(MS.IntptrTy);
994  if (IntptrSize == kOriginSize) return Origin;
995  assert(IntptrSize == kOriginSize * 2);
996  Origin = IRB.CreateIntCast(Origin, MS.IntptrTy, /* isSigned */ false);
997  return IRB.CreateOr(Origin, IRB.CreateShl(Origin, kOriginSize * 8));
998  }
999 
1000  /// Fill memory range with the given origin value.
1001  void paintOrigin(IRBuilder<> &IRB, Value *Origin, Value *OriginPtr,
1002  unsigned Size, unsigned Alignment) {
1003  const DataLayout &DL = F.getParent()->getDataLayout();
1004  unsigned IntptrAlignment = DL.getABITypeAlignment(MS.IntptrTy);
1005  unsigned IntptrSize = DL.getTypeStoreSize(MS.IntptrTy);
1006  assert(IntptrAlignment >= kMinOriginAlignment);
1007  assert(IntptrSize >= kOriginSize);
1008 
1009  unsigned Ofs = 0;
1010  unsigned CurrentAlignment = Alignment;
1011  if (Alignment >= IntptrAlignment && IntptrSize > kOriginSize) {
1012  Value *IntptrOrigin = originToIntptr(IRB, Origin);
1013  Value *IntptrOriginPtr =
1014  IRB.CreatePointerCast(OriginPtr, PointerType::get(MS.IntptrTy, 0));
1015  for (unsigned i = 0; i < Size / IntptrSize; ++i) {
1016  Value *Ptr = i ? IRB.CreateConstGEP1_32(MS.IntptrTy, IntptrOriginPtr, i)
1017  : IntptrOriginPtr;
1018  IRB.CreateAlignedStore(IntptrOrigin, Ptr, CurrentAlignment);
1019  Ofs += IntptrSize / kOriginSize;
1020  CurrentAlignment = IntptrAlignment;
1021  }
1022  }
1023 
1024  for (unsigned i = Ofs; i < (Size + kOriginSize - 1) / kOriginSize; ++i) {
1025  Value *GEP =
1026  i ? IRB.CreateConstGEP1_32(nullptr, OriginPtr, i) : OriginPtr;
1027  IRB.CreateAlignedStore(Origin, GEP, CurrentAlignment);
1028  CurrentAlignment = kMinOriginAlignment;
1029  }
1030  }
1031 
1032  void storeOrigin(IRBuilder<> &IRB, Value *Addr, Value *Shadow, Value *Origin,
1033  Value *OriginPtr, unsigned Alignment, bool AsCall) {
1034  const DataLayout &DL = F.getParent()->getDataLayout();
1035  unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment);
1036  unsigned StoreSize = DL.getTypeStoreSize(Shadow->getType());
1037  if (Shadow->getType()->isAggregateType()) {
1038  paintOrigin(IRB, updateOrigin(Origin, IRB), OriginPtr, StoreSize,
1039  OriginAlignment);
1040  } else {
1041  Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
1042  Constant *ConstantShadow = dyn_cast_or_null<Constant>(ConvertedShadow);
1043  if (ConstantShadow) {
1044  if (ClCheckConstantShadow && !ConstantShadow->isZeroValue())
1045  paintOrigin(IRB, updateOrigin(Origin, IRB), OriginPtr, StoreSize,
1046  OriginAlignment);
1047  return;
1048  }
1049 
1050  unsigned TypeSizeInBits =
1051  DL.getTypeSizeInBits(ConvertedShadow->getType());
1052  unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits);
1053  if (AsCall && SizeIndex < kNumberOfAccessSizes && !MS.CompileKernel) {
1054  Value *Fn = MS.MaybeStoreOriginFn[SizeIndex];
1055  Value *ConvertedShadow2 = IRB.CreateZExt(
1056  ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
1057  IRB.CreateCall(Fn, {ConvertedShadow2,
1058  IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),
1059  Origin});
1060  } else {
1061  Value *Cmp = IRB.CreateICmpNE(
1062  ConvertedShadow, getCleanShadow(ConvertedShadow), "_mscmp");
1064  Cmp, &*IRB.GetInsertPoint(), false, MS.OriginStoreWeights);
1065  IRBuilder<> IRBNew(CheckTerm);
1066  paintOrigin(IRBNew, updateOrigin(Origin, IRBNew), OriginPtr, StoreSize,
1067  OriginAlignment);
1068  }
1069  }
1070  }
1071 
1072  void materializeStores(bool InstrumentWithCalls) {
1073  for (StoreInst *SI : StoreList) {
1074  IRBuilder<> IRB(SI);
1075  Value *Val = SI->getValueOperand();
1076  Value *Addr = SI->getPointerOperand();
1077  Value *Shadow = SI->isAtomic() ? getCleanShadow(Val) : getShadow(Val);
1078  Value *ShadowPtr, *OriginPtr;
1079  Type *ShadowTy = Shadow->getType();
1080  unsigned Alignment = SI->getAlignment();
1081  unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment);
1082  std::tie(ShadowPtr, OriginPtr) =
1083  getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ true);
1084 
1085  StoreInst *NewSI = IRB.CreateAlignedStore(Shadow, ShadowPtr, Alignment);
1086  LLVM_DEBUG(dbgs() << " STORE: " << *NewSI << "\n");
1087  (void)NewSI;
1088 
1089  if (SI->isAtomic())
1090  SI->setOrdering(addReleaseOrdering(SI->getOrdering()));
1091 
1092  if (MS.TrackOrigins && !SI->isAtomic())
1093  storeOrigin(IRB, Addr, Shadow, getOrigin(Val), OriginPtr,
1094  OriginAlignment, InstrumentWithCalls);
1095  }
1096  }
1097 
1098  /// Helper function to insert a warning at IRB's current insert point.
1099  void insertWarningFn(IRBuilder<> &IRB, Value *Origin) {
1100  if (!Origin)
1101  Origin = (Value *)IRB.getInt32(0);
1102  if (MS.CompileKernel) {
1103  IRB.CreateCall(MS.WarningFn, Origin);
1104  } else {
1105  if (MS.TrackOrigins) {
1106  IRB.CreateStore(Origin, MS.OriginTLS);
1107  }
1108  IRB.CreateCall(MS.WarningFn, {});
1109  }
1110  IRB.CreateCall(MS.EmptyAsm, {});
1111  // FIXME: Insert UnreachableInst if !MS.Recover?
1112  // This may invalidate some of the following checks and needs to be done
1113  // at the very end.
1114  }
1115 
1116  void materializeOneCheck(Instruction *OrigIns, Value *Shadow, Value *Origin,
1117  bool AsCall) {
1118  IRBuilder<> IRB(OrigIns);
1119  LLVM_DEBUG(dbgs() << " SHAD0 : " << *Shadow << "\n");
1120  Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
1121  LLVM_DEBUG(dbgs() << " SHAD1 : " << *ConvertedShadow << "\n");
1122 
1123  Constant *ConstantShadow = dyn_cast_or_null<Constant>(ConvertedShadow);
1124  if (ConstantShadow) {
1125  if (ClCheckConstantShadow && !ConstantShadow->isZeroValue()) {
1126  insertWarningFn(IRB, Origin);
1127  }
1128  return;
1129  }
1130 
1131  const DataLayout &DL = OrigIns->getModule()->getDataLayout();
1132 
1133  unsigned TypeSizeInBits = DL.getTypeSizeInBits(ConvertedShadow->getType());
1134  unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits);
1135  if (AsCall && SizeIndex < kNumberOfAccessSizes && !MS.CompileKernel) {
1136  Value *Fn = MS.MaybeWarningFn[SizeIndex];
1137  Value *ConvertedShadow2 =
1138  IRB.CreateZExt(ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
1139  IRB.CreateCall(Fn, {ConvertedShadow2, MS.TrackOrigins && Origin
1140  ? Origin
1141  : (Value *)IRB.getInt32(0)});
1142  } else {
1143  Value *Cmp = IRB.CreateICmpNE(ConvertedShadow,
1144  getCleanShadow(ConvertedShadow), "_mscmp");
1146  Cmp, OrigIns,
1147  /* Unreachable */ !MS.Recover, MS.ColdCallWeights);
1148 
1149  IRB.SetInsertPoint(CheckTerm);
1150  insertWarningFn(IRB, Origin);
1151  LLVM_DEBUG(dbgs() << " CHECK: " << *Cmp << "\n");
1152  }
1153  }
1154 
1155  void materializeChecks(bool InstrumentWithCalls) {
1156  for (const auto &ShadowData : InstrumentationList) {
1157  Instruction *OrigIns = ShadowData.OrigIns;
1158  Value *Shadow = ShadowData.Shadow;
1159  Value *Origin = ShadowData.Origin;
1160  materializeOneCheck(OrigIns, Shadow, Origin, InstrumentWithCalls);
1161  }
1162  LLVM_DEBUG(dbgs() << "DONE:\n" << F);
1163  }
1164 
1165  BasicBlock *insertKmsanPrologue(Function &F) {
1166  BasicBlock *ret =
1169  Value *ContextState = IRB.CreateCall(MS.MsanGetContextStateFn, {});
1170  Constant *Zero = IRB.getInt32(0);
1171  MS.ParamTLS =
1172  IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(0)}, "param_shadow");
1173  MS.RetvalTLS =
1174  IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(1)}, "retval_shadow");
1175  MS.VAArgTLS =
1176  IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(2)}, "va_arg_shadow");
1177  MS.VAArgOriginTLS =
1178  IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(3)}, "va_arg_origin");
1179  MS.VAArgOverflowSizeTLS = IRB.CreateGEP(
1180  ContextState, {Zero, IRB.getInt32(4)}, "va_arg_overflow_size");
1181  MS.ParamOriginTLS =
1182  IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(5)}, "param_origin");
1183  MS.RetvalOriginTLS =
1184  IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(6)}, "retval_origin");
1185  return ret;
1186  }
1187 
1188  /// Add MemorySanitizer instrumentation to a function.
1189  bool runOnFunction() {
1190  // In the presence of unreachable blocks, we may see Phi nodes with
1191  // incoming nodes from such blocks. Since InstVisitor skips unreachable
1192  // blocks, such nodes will not have any shadow value associated with them.
1193  // It's easier to remove unreachable blocks than deal with missing shadow.
1195 
1196  // Iterate all BBs in depth-first order and create shadow instructions
1197  // for all instructions (where applicable).
1198  // For PHI nodes we create dummy shadow PHIs which will be finalized later.
1199  for (BasicBlock *BB : depth_first(ActualFnStart))
1200  visit(*BB);
1201 
1202  // Finalize PHI nodes.
1203  for (PHINode *PN : ShadowPHINodes) {
1204  PHINode *PNS = cast<PHINode>(getShadow(PN));
1205  PHINode *PNO = MS.TrackOrigins ? cast<PHINode>(getOrigin(PN)) : nullptr;
1206  size_t NumValues = PN->getNumIncomingValues();
1207  for (size_t v = 0; v < NumValues; v++) {
1208  PNS->addIncoming(getShadow(PN, v), PN->getIncomingBlock(v));
1209  if (PNO) PNO->addIncoming(getOrigin(PN, v), PN->getIncomingBlock(v));
1210  }
1211  }
1212 
1213  VAHelper->finalizeInstrumentation();
1214 
1215  bool InstrumentWithCalls = ClInstrumentationWithCallThreshold >= 0 &&
1216  InstrumentationList.size() + StoreList.size() >
1218 
1219  // Insert shadow value checks.
1220  materializeChecks(InstrumentWithCalls);
1221 
1222  // Delayed instrumentation of StoreInst.
1223  // This may not add new address checks.
1224  materializeStores(InstrumentWithCalls);
1225 
1226  return true;
1227  }
1228 
1229  /// Compute the shadow type that corresponds to a given Value.
1230  Type *getShadowTy(Value *V) {
1231  return getShadowTy(V->getType());
1232  }
1233 
1234  /// Compute the shadow type that corresponds to a given Type.
1235  Type *getShadowTy(Type *OrigTy) {
1236  if (!OrigTy->isSized()) {
1237  return nullptr;
1238  }
1239  // For integer type, shadow is the same as the original type.
1240  // This may return weird-sized types like i1.
1241  if (IntegerType *IT = dyn_cast<IntegerType>(OrigTy))
1242  return IT;
1243  const DataLayout &DL = F.getParent()->getDataLayout();
1244  if (VectorType *VT = dyn_cast<VectorType>(OrigTy)) {
1245  uint32_t EltSize = DL.getTypeSizeInBits(VT->getElementType());
1246  return VectorType::get(IntegerType::get(*MS.C, EltSize),
1247  VT->getNumElements());
1248  }
1249  if (ArrayType *AT = dyn_cast<ArrayType>(OrigTy)) {
1250  return ArrayType::get(getShadowTy(AT->getElementType()),
1251  AT->getNumElements());
1252  }
1253  if (StructType *ST = dyn_cast<StructType>(OrigTy)) {
1254  SmallVector<Type*, 4> Elements;
1255  for (unsigned i = 0, n = ST->getNumElements(); i < n; i++)
1256  Elements.push_back(getShadowTy(ST->getElementType(i)));
1257  StructType *Res = StructType::get(*MS.C, Elements, ST->isPacked());
1258  LLVM_DEBUG(dbgs() << "getShadowTy: " << *ST << " ===> " << *Res << "\n");
1259  return Res;
1260  }
1261  uint32_t TypeSize = DL.getTypeSizeInBits(OrigTy);
1262  return IntegerType::get(*MS.C, TypeSize);
1263  }
1264 
1265  /// Flatten a vector type.
1266  Type *getShadowTyNoVec(Type *ty) {
1267  if (VectorType *vt = dyn_cast<VectorType>(ty))
1268  return IntegerType::get(*MS.C, vt->getBitWidth());
1269  return ty;
1270  }
1271 
1272  /// Convert a shadow value to it's flattened variant.
1273  Value *convertToShadowTyNoVec(Value *V, IRBuilder<> &IRB) {
1274  Type *Ty = V->getType();
1275  Type *NoVecTy = getShadowTyNoVec(Ty);
1276  if (Ty == NoVecTy) return V;
1277  return IRB.CreateBitCast(V, NoVecTy);
1278  }
1279 
1280  /// Compute the integer shadow offset that corresponds to a given
1281  /// application address.
1282  ///
1283  /// Offset = (Addr & ~AndMask) ^ XorMask
1284  Value *getShadowPtrOffset(Value *Addr, IRBuilder<> &IRB) {
1285  Value *OffsetLong = IRB.CreatePointerCast(Addr, MS.IntptrTy);
1286 
1287  uint64_t AndMask = MS.MapParams->AndMask;
1288  if (AndMask)
1289  OffsetLong =
1290  IRB.CreateAnd(OffsetLong, ConstantInt::get(MS.IntptrTy, ~AndMask));
1291 
1292  uint64_t XorMask = MS.MapParams->XorMask;
1293  if (XorMask)
1294  OffsetLong =
1295  IRB.CreateXor(OffsetLong, ConstantInt::get(MS.IntptrTy, XorMask));
1296  return OffsetLong;
1297  }
1298 
1299  /// Compute the shadow and origin addresses corresponding to a given
1300  /// application address.
1301  ///
1302  /// Shadow = ShadowBase + Offset
1303  /// Origin = (OriginBase + Offset) & ~3ULL
1304  std::pair<Value *, Value *> getShadowOriginPtrUserspace(Value *Addr,
1305  IRBuilder<> &IRB,
1306  Type *ShadowTy,
1307  unsigned Alignment) {
1308  Value *ShadowOffset = getShadowPtrOffset(Addr, IRB);
1309  Value *ShadowLong = ShadowOffset;
1310  uint64_t ShadowBase = MS.MapParams->ShadowBase;
1311  if (ShadowBase != 0) {
1312  ShadowLong =
1313  IRB.CreateAdd(ShadowLong,
1314  ConstantInt::get(MS.IntptrTy, ShadowBase));
1315  }
1316  Value *ShadowPtr =
1317  IRB.CreateIntToPtr(ShadowLong, PointerType::get(ShadowTy, 0));
1318  Value *OriginPtr = nullptr;
1319  if (MS.TrackOrigins) {
1320  Value *OriginLong = ShadowOffset;
1321  uint64_t OriginBase = MS.MapParams->OriginBase;
1322  if (OriginBase != 0)
1323  OriginLong = IRB.CreateAdd(OriginLong,
1324  ConstantInt::get(MS.IntptrTy, OriginBase));
1325  if (Alignment < kMinOriginAlignment) {
1326  uint64_t Mask = kMinOriginAlignment - 1;
1327  OriginLong =
1328  IRB.CreateAnd(OriginLong, ConstantInt::get(MS.IntptrTy, ~Mask));
1329  }
1330  OriginPtr =
1331  IRB.CreateIntToPtr(OriginLong, PointerType::get(IRB.getInt32Ty(), 0));
1332  }
1333  return std::make_pair(ShadowPtr, OriginPtr);
1334  }
1335 
1336  std::pair<Value *, Value *>
1337  getShadowOriginPtrKernel(Value *Addr, IRBuilder<> &IRB, Type *ShadowTy,
1338  unsigned Alignment, bool isStore) {
1339  Value *ShadowOriginPtrs;
1340  const DataLayout &DL = F.getParent()->getDataLayout();
1341  int Size = DL.getTypeStoreSize(ShadowTy);
1342 
1343  Value *Getter = MS.getKmsanShadowOriginAccessFn(isStore, Size);
1344  Value *AddrCast =
1345  IRB.CreatePointerCast(Addr, PointerType::get(IRB.getInt8Ty(), 0));
1346  if (Getter) {
1347  ShadowOriginPtrs = IRB.CreateCall(Getter, AddrCast);
1348  } else {
1349  Value *SizeVal = ConstantInt::get(MS.IntptrTy, Size);
1350  ShadowOriginPtrs = IRB.CreateCall(isStore ? MS.MsanMetadataPtrForStoreN
1351  : MS.MsanMetadataPtrForLoadN,
1352  {AddrCast, SizeVal});
1353  }
1354  Value *ShadowPtr = IRB.CreateExtractValue(ShadowOriginPtrs, 0);
1355  ShadowPtr = IRB.CreatePointerCast(ShadowPtr, PointerType::get(ShadowTy, 0));
1356  Value *OriginPtr = IRB.CreateExtractValue(ShadowOriginPtrs, 1);
1357 
1358  return std::make_pair(ShadowPtr, OriginPtr);
1359  }
1360 
1361  std::pair<Value *, Value *> getShadowOriginPtr(Value *Addr, IRBuilder<> &IRB,
1362  Type *ShadowTy,
1363  unsigned Alignment,
1364  bool isStore) {
1365  std::pair<Value *, Value *> ret;
1366  if (MS.CompileKernel)
1367  ret = getShadowOriginPtrKernel(Addr, IRB, ShadowTy, Alignment, isStore);
1368  else
1369  ret = getShadowOriginPtrUserspace(Addr, IRB, ShadowTy, Alignment);
1370  return ret;
1371  }
1372 
1373  /// Compute the shadow address for a given function argument.
1374  ///
1375  /// Shadow = ParamTLS+ArgOffset.
1376  Value *getShadowPtrForArgument(Value *A, IRBuilder<> &IRB,
1377  int ArgOffset) {
1378  Value *Base = IRB.CreatePointerCast(MS.ParamTLS, MS.IntptrTy);
1379  if (ArgOffset)
1380  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
1381  return IRB.CreateIntToPtr(Base, PointerType::get(getShadowTy(A), 0),
1382  "_msarg");
1383  }
1384 
1385  /// Compute the origin address for a given function argument.
1386  Value *getOriginPtrForArgument(Value *A, IRBuilder<> &IRB,
1387  int ArgOffset) {
1388  if (!MS.TrackOrigins)
1389  return nullptr;
1390  Value *Base = IRB.CreatePointerCast(MS.ParamOriginTLS, MS.IntptrTy);
1391  if (ArgOffset)
1392  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
1393  return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0),
1394  "_msarg_o");
1395  }
1396 
1397  /// Compute the shadow address for a retval.
1398  Value *getShadowPtrForRetval(Value *A, IRBuilder<> &IRB) {
1399  return IRB.CreatePointerCast(MS.RetvalTLS,
1400  PointerType::get(getShadowTy(A), 0),
1401  "_msret");
1402  }
1403 
1404  /// Compute the origin address for a retval.
1405  Value *getOriginPtrForRetval(IRBuilder<> &IRB) {
1406  // We keep a single origin for the entire retval. Might be too optimistic.
1407  return MS.RetvalOriginTLS;
1408  }
1409 
1410  /// Set SV to be the shadow value for V.
1411  void setShadow(Value *V, Value *SV) {
1412  assert(!ShadowMap.count(V) && "Values may only have one shadow");
1413  ShadowMap[V] = PropagateShadow ? SV : getCleanShadow(V);
1414  }
1415 
1416  /// Set Origin to be the origin value for V.
1417  void setOrigin(Value *V, Value *Origin) {
1418  if (!MS.TrackOrigins) return;
1419  assert(!OriginMap.count(V) && "Values may only have one origin");
1420  LLVM_DEBUG(dbgs() << "ORIGIN: " << *V << " ==> " << *Origin << "\n");
1421  OriginMap[V] = Origin;
1422  }
1423 
1424  Constant *getCleanShadow(Type *OrigTy) {
1425  Type *ShadowTy = getShadowTy(OrigTy);
1426  if (!ShadowTy)
1427  return nullptr;
1428  return Constant::getNullValue(ShadowTy);
1429  }
1430 
1431  /// Create a clean shadow value for a given value.
1432  ///
1433  /// Clean shadow (all zeroes) means all bits of the value are defined
1434  /// (initialized).
1435  Constant *getCleanShadow(Value *V) {
1436  return getCleanShadow(V->getType());
1437  }
1438 
1439  /// Create a dirty shadow of a given shadow type.
1440  Constant *getPoisonedShadow(Type *ShadowTy) {
1441  assert(ShadowTy);
1442  if (isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy))
1443  return Constant::getAllOnesValue(ShadowTy);
1444  if (ArrayType *AT = dyn_cast<ArrayType>(ShadowTy)) {
1445  SmallVector<Constant *, 4> Vals(AT->getNumElements(),
1446  getPoisonedShadow(AT->getElementType()));
1447  return ConstantArray::get(AT, Vals);
1448  }
1449  if (StructType *ST = dyn_cast<StructType>(ShadowTy)) {
1451  for (unsigned i = 0, n = ST->getNumElements(); i < n; i++)
1452  Vals.push_back(getPoisonedShadow(ST->getElementType(i)));
1453  return ConstantStruct::get(ST, Vals);
1454  }
1455  llvm_unreachable("Unexpected shadow type");
1456  }
1457 
1458  /// Create a dirty shadow for a given value.
1459  Constant *getPoisonedShadow(Value *V) {
1460  Type *ShadowTy = getShadowTy(V);
1461  if (!ShadowTy)
1462  return nullptr;
1463  return getPoisonedShadow(ShadowTy);
1464  }
1465 
1466  /// Create a clean (zero) origin.
1467  Value *getCleanOrigin() {
1468  return Constant::getNullValue(MS.OriginTy);
1469  }
1470 
1471  /// Get the shadow value for a given Value.
1472  ///
1473  /// This function either returns the value set earlier with setShadow,
1474  /// or extracts if from ParamTLS (for function arguments).
1475  Value *getShadow(Value *V) {
1476  if (!PropagateShadow) return getCleanShadow(V);
1477  if (Instruction *I = dyn_cast<Instruction>(V)) {
1478  if (I->getMetadata("nosanitize"))
1479  return getCleanShadow(V);
1480  // For instructions the shadow is already stored in the map.
1481  Value *Shadow = ShadowMap[V];
1482  if (!Shadow) {
1483  LLVM_DEBUG(dbgs() << "No shadow: " << *V << "\n" << *(I->getParent()));
1484  (void)I;
1485  assert(Shadow && "No shadow for a value");
1486  }
1487  return Shadow;
1488  }
1489  if (UndefValue *U = dyn_cast<UndefValue>(V)) {
1490  Value *AllOnes = PoisonUndef ? getPoisonedShadow(V) : getCleanShadow(V);
1491  LLVM_DEBUG(dbgs() << "Undef: " << *U << " ==> " << *AllOnes << "\n");
1492  (void)U;
1493  return AllOnes;
1494  }
1495  if (Argument *A = dyn_cast<Argument>(V)) {
1496  // For arguments we compute the shadow on demand and store it in the map.
1497  Value **ShadowPtr = &ShadowMap[V];
1498  if (*ShadowPtr)
1499  return *ShadowPtr;
1500  Function *F = A->getParent();
1501  IRBuilder<> EntryIRB(ActualFnStart->getFirstNonPHI());
1502  unsigned ArgOffset = 0;
1503  const DataLayout &DL = F->getParent()->getDataLayout();
1504  for (auto &FArg : F->args()) {
1505  if (!FArg.getType()->isSized()) {
1506  LLVM_DEBUG(dbgs() << "Arg is not sized\n");
1507  continue;
1508  }
1509  unsigned Size =
1510  FArg.hasByValAttr()
1511  ? DL.getTypeAllocSize(FArg.getType()->getPointerElementType())
1512  : DL.getTypeAllocSize(FArg.getType());
1513  if (A == &FArg) {
1514  bool Overflow = ArgOffset + Size > kParamTLSSize;
1515  Value *Base = getShadowPtrForArgument(&FArg, EntryIRB, ArgOffset);
1516  if (FArg.hasByValAttr()) {
1517  // ByVal pointer itself has clean shadow. We copy the actual
1518  // argument shadow to the underlying memory.
1519  // Figure out maximal valid memcpy alignment.
1520  unsigned ArgAlign = FArg.getParamAlignment();
1521  if (ArgAlign == 0) {
1522  Type *EltType = A->getType()->getPointerElementType();
1523  ArgAlign = DL.getABITypeAlignment(EltType);
1524  }
1525  Value *CpShadowPtr =
1526  getShadowOriginPtr(V, EntryIRB, EntryIRB.getInt8Ty(), ArgAlign,
1527  /*isStore*/ true)
1528  .first;
1529  // TODO(glider): need to copy origins.
1530  if (Overflow) {
1531  // ParamTLS overflow.
1532  EntryIRB.CreateMemSet(
1533  CpShadowPtr, Constant::getNullValue(EntryIRB.getInt8Ty()),
1534  Size, ArgAlign);
1535  } else {
1536  unsigned CopyAlign = std::min(ArgAlign, kShadowTLSAlignment);
1537  Value *Cpy = EntryIRB.CreateMemCpy(CpShadowPtr, CopyAlign, Base,
1538  CopyAlign, Size);
1539  LLVM_DEBUG(dbgs() << " ByValCpy: " << *Cpy << "\n");
1540  (void)Cpy;
1541  }
1542  *ShadowPtr = getCleanShadow(V);
1543  } else {
1544  if (Overflow) {
1545  // ParamTLS overflow.
1546  *ShadowPtr = getCleanShadow(V);
1547  } else {
1548  *ShadowPtr =
1549  EntryIRB.CreateAlignedLoad(Base, kShadowTLSAlignment);
1550  }
1551  }
1552  LLVM_DEBUG(dbgs()
1553  << " ARG: " << FArg << " ==> " << **ShadowPtr << "\n");
1554  if (MS.TrackOrigins && !Overflow) {
1555  Value *OriginPtr =
1556  getOriginPtrForArgument(&FArg, EntryIRB, ArgOffset);
1557  setOrigin(A, EntryIRB.CreateLoad(OriginPtr));
1558  } else {
1559  setOrigin(A, getCleanOrigin());
1560  }
1561  }
1562  ArgOffset += alignTo(Size, kShadowTLSAlignment);
1563  }
1564  assert(*ShadowPtr && "Could not find shadow for an argument");
1565  return *ShadowPtr;
1566  }
1567  // For everything else the shadow is zero.
1568  return getCleanShadow(V);
1569  }
1570 
1571  /// Get the shadow for i-th argument of the instruction I.
1572  Value *getShadow(Instruction *I, int i) {
1573  return getShadow(I->getOperand(i));
1574  }
1575 
1576  /// Get the origin for a value.
1577  Value *getOrigin(Value *V) {
1578  if (!MS.TrackOrigins) return nullptr;
1579  if (!PropagateShadow) return getCleanOrigin();
1580  if (isa<Constant>(V)) return getCleanOrigin();
1581  assert((isa<Instruction>(V) || isa<Argument>(V)) &&
1582  "Unexpected value type in getOrigin()");
1583  if (Instruction *I = dyn_cast<Instruction>(V)) {
1584  if (I->getMetadata("nosanitize"))
1585  return getCleanOrigin();
1586  }
1587  Value *Origin = OriginMap[V];
1588  assert(Origin && "Missing origin");
1589  return Origin;
1590  }
1591 
1592  /// Get the origin for i-th argument of the instruction I.
1593  Value *getOrigin(Instruction *I, int i) {
1594  return getOrigin(I->getOperand(i));
1595  }
1596 
1597  /// Remember the place where a shadow check should be inserted.
1598  ///
1599  /// This location will be later instrumented with a check that will print a
1600  /// UMR warning in runtime if the shadow value is not 0.
1601  void insertShadowCheck(Value *Shadow, Value *Origin, Instruction *OrigIns) {
1602  assert(Shadow);
1603  if (!InsertChecks) return;
1604 #ifndef NDEBUG
1605  Type *ShadowTy = Shadow->getType();
1606  assert((isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) &&
1607  "Can only insert checks for integer and vector shadow types");
1608 #endif
1609  InstrumentationList.push_back(
1610  ShadowOriginAndInsertPoint(Shadow, Origin, OrigIns));
1611  }
1612 
1613  /// Remember the place where a shadow check should be inserted.
1614  ///
1615  /// This location will be later instrumented with a check that will print a
1616  /// UMR warning in runtime if the value is not fully defined.
1617  void insertShadowCheck(Value *Val, Instruction *OrigIns) {
1618  assert(Val);
1619  Value *Shadow, *Origin;
1620  if (ClCheckConstantShadow) {
1621  Shadow = getShadow(Val);
1622  if (!Shadow) return;
1623  Origin = getOrigin(Val);
1624  } else {
1625  Shadow = dyn_cast_or_null<Instruction>(getShadow(Val));
1626  if (!Shadow) return;
1627  Origin = dyn_cast_or_null<Instruction>(getOrigin(Val));
1628  }
1629  insertShadowCheck(Shadow, Origin, OrigIns);
1630  }
1631 
1632  AtomicOrdering addReleaseOrdering(AtomicOrdering a) {
1633  switch (a) {
1639  return AtomicOrdering::Release;
1645  }
1646  llvm_unreachable("Unknown ordering");
1647  }
1648 
1649  AtomicOrdering addAcquireOrdering(AtomicOrdering a) {
1650  switch (a) {
1656  return AtomicOrdering::Acquire;
1662  }
1663  llvm_unreachable("Unknown ordering");
1664  }
1665 
1666  // ------------------- Visitors.
1668  void visit(Instruction &I) {
1669  if (!I.getMetadata("nosanitize"))
1671  }
1672 
1673  /// Instrument LoadInst
1674  ///
1675  /// Loads the corresponding shadow and (optionally) origin.
1676  /// Optionally, checks that the load address is fully defined.
1677  void visitLoadInst(LoadInst &I) {
1678  assert(I.getType()->isSized() && "Load type must have size");
1679  assert(!I.getMetadata("nosanitize"));
1680  IRBuilder<> IRB(I.getNextNode());
1681  Type *ShadowTy = getShadowTy(&I);
1682  Value *Addr = I.getPointerOperand();
1683  Value *ShadowPtr, *OriginPtr;
1684  unsigned Alignment = I.getAlignment();
1685  if (PropagateShadow) {
1686  std::tie(ShadowPtr, OriginPtr) =
1687  getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false);
1688  setShadow(&I, IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_msld"));
1689  } else {
1690  setShadow(&I, getCleanShadow(&I));
1691  }
1692 
1694  insertShadowCheck(I.getPointerOperand(), &I);
1695 
1696  if (I.isAtomic())
1697  I.setOrdering(addAcquireOrdering(I.getOrdering()));
1698 
1699  if (MS.TrackOrigins) {
1700  if (PropagateShadow) {
1701  unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment);
1702  setOrigin(&I, IRB.CreateAlignedLoad(OriginPtr, OriginAlignment));
1703  } else {
1704  setOrigin(&I, getCleanOrigin());
1705  }
1706  }
1707  }
1708 
1709  /// Instrument StoreInst
1710  ///
1711  /// Stores the corresponding shadow and (optionally) origin.
1712  /// Optionally, checks that the store address is fully defined.
1713  void visitStoreInst(StoreInst &I) {
1714  StoreList.push_back(&I);
1716  insertShadowCheck(I.getPointerOperand(), &I);
1717  }
1718 
1719  void handleCASOrRMW(Instruction &I) {
1720  assert(isa<AtomicRMWInst>(I) || isa<AtomicCmpXchgInst>(I));
1721 
1722  IRBuilder<> IRB(&I);
1723  Value *Addr = I.getOperand(0);
1724  Value *ShadowPtr = getShadowOriginPtr(Addr, IRB, I.getType(),
1725  /*Alignment*/ 1, /*isStore*/ true)
1726  .first;
1727 
1729  insertShadowCheck(Addr, &I);
1730 
1731  // Only test the conditional argument of cmpxchg instruction.
1732  // The other argument can potentially be uninitialized, but we can not
1733  // detect this situation reliably without possible false positives.
1734  if (isa<AtomicCmpXchgInst>(I))
1735  insertShadowCheck(I.getOperand(1), &I);
1736 
1737  IRB.CreateStore(getCleanShadow(&I), ShadowPtr);
1738 
1739  setShadow(&I, getCleanShadow(&I));
1740  setOrigin(&I, getCleanOrigin());
1741  }
1742 
1743  void visitAtomicRMWInst(AtomicRMWInst &I) {
1744  handleCASOrRMW(I);
1745  I.setOrdering(addReleaseOrdering(I.getOrdering()));
1746  }
1747 
1748  void visitAtomicCmpXchgInst(AtomicCmpXchgInst &I) {
1749  handleCASOrRMW(I);
1750  I.setSuccessOrdering(addReleaseOrdering(I.getSuccessOrdering()));
1751  }
1752 
1753  // Vector manipulation.
1754  void visitExtractElementInst(ExtractElementInst &I) {
1755  insertShadowCheck(I.getOperand(1), &I);
1756  IRBuilder<> IRB(&I);
1757  setShadow(&I, IRB.CreateExtractElement(getShadow(&I, 0), I.getOperand(1),
1758  "_msprop"));
1759  setOrigin(&I, getOrigin(&I, 0));
1760  }
1761 
1762  void visitInsertElementInst(InsertElementInst &I) {
1763  insertShadowCheck(I.getOperand(2), &I);
1764  IRBuilder<> IRB(&I);
1765  setShadow(&I, IRB.CreateInsertElement(getShadow(&I, 0), getShadow(&I, 1),
1766  I.getOperand(2), "_msprop"));
1767  setOriginForNaryOp(I);
1768  }
1769 
1770  void visitShuffleVectorInst(ShuffleVectorInst &I) {
1771  insertShadowCheck(I.getOperand(2), &I);
1772  IRBuilder<> IRB(&I);
1773  setShadow(&I, IRB.CreateShuffleVector(getShadow(&I, 0), getShadow(&I, 1),
1774  I.getOperand(2), "_msprop"));
1775  setOriginForNaryOp(I);
1776  }
1777 
1778  // Casts.
1779  void visitSExtInst(SExtInst &I) {
1780  IRBuilder<> IRB(&I);
1781  setShadow(&I, IRB.CreateSExt(getShadow(&I, 0), I.getType(), "_msprop"));
1782  setOrigin(&I, getOrigin(&I, 0));
1783  }
1784 
1785  void visitZExtInst(ZExtInst &I) {
1786  IRBuilder<> IRB(&I);
1787  setShadow(&I, IRB.CreateZExt(getShadow(&I, 0), I.getType(), "_msprop"));
1788  setOrigin(&I, getOrigin(&I, 0));
1789  }
1790 
1791  void visitTruncInst(TruncInst &I) {
1792  IRBuilder<> IRB(&I);
1793  setShadow(&I, IRB.CreateTrunc(getShadow(&I, 0), I.getType(), "_msprop"));
1794  setOrigin(&I, getOrigin(&I, 0));
1795  }
1796 
1797  void visitBitCastInst(BitCastInst &I) {
1798  // Special case: if this is the bitcast (there is exactly 1 allowed) between
1799  // a musttail call and a ret, don't instrument. New instructions are not
1800  // allowed after a musttail call.
1801  if (auto *CI = dyn_cast<CallInst>(I.getOperand(0)))
1802  if (CI->isMustTailCall())
1803  return;
1804  IRBuilder<> IRB(&I);
1805  setShadow(&I, IRB.CreateBitCast(getShadow(&I, 0), getShadowTy(&I)));
1806  setOrigin(&I, getOrigin(&I, 0));
1807  }
1808 
1809  void visitPtrToIntInst(PtrToIntInst &I) {
1810  IRBuilder<> IRB(&I);
1811  setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false,
1812  "_msprop_ptrtoint"));
1813  setOrigin(&I, getOrigin(&I, 0));
1814  }
1815 
1816  void visitIntToPtrInst(IntToPtrInst &I) {
1817  IRBuilder<> IRB(&I);
1818  setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false,
1819  "_msprop_inttoptr"));
1820  setOrigin(&I, getOrigin(&I, 0));
1821  }
1822 
1823  void visitFPToSIInst(CastInst& I) { handleShadowOr(I); }
1824  void visitFPToUIInst(CastInst& I) { handleShadowOr(I); }
1825  void visitSIToFPInst(CastInst& I) { handleShadowOr(I); }
1826  void visitUIToFPInst(CastInst& I) { handleShadowOr(I); }
1827  void visitFPExtInst(CastInst& I) { handleShadowOr(I); }
1828  void visitFPTruncInst(CastInst& I) { handleShadowOr(I); }
1829 
1830  /// Propagate shadow for bitwise AND.
1831  ///
1832  /// This code is exact, i.e. if, for example, a bit in the left argument
1833  /// is defined and 0, then neither the value not definedness of the
1834  /// corresponding bit in B don't affect the resulting shadow.
1835  void visitAnd(BinaryOperator &I) {
1836  IRBuilder<> IRB(&I);
1837  // "And" of 0 and a poisoned value results in unpoisoned value.
1838  // 1&1 => 1; 0&1 => 0; p&1 => p;
1839  // 1&0 => 0; 0&0 => 0; p&0 => 0;
1840  // 1&p => p; 0&p => 0; p&p => p;
1841  // S = (S1 & S2) | (V1 & S2) | (S1 & V2)
1842  Value *S1 = getShadow(&I, 0);
1843  Value *S2 = getShadow(&I, 1);
1844  Value *V1 = I.getOperand(0);
1845  Value *V2 = I.getOperand(1);
1846  if (V1->getType() != S1->getType()) {
1847  V1 = IRB.CreateIntCast(V1, S1->getType(), false);
1848  V2 = IRB.CreateIntCast(V2, S2->getType(), false);
1849  }
1850  Value *S1S2 = IRB.CreateAnd(S1, S2);
1851  Value *V1S2 = IRB.CreateAnd(V1, S2);
1852  Value *S1V2 = IRB.CreateAnd(S1, V2);
1853  setShadow(&I, IRB.CreateOr(S1S2, IRB.CreateOr(V1S2, S1V2)));
1854  setOriginForNaryOp(I);
1855  }
1856 
1857  void visitOr(BinaryOperator &I) {
1858  IRBuilder<> IRB(&I);
1859  // "Or" of 1 and a poisoned value results in unpoisoned value.
1860  // 1|1 => 1; 0|1 => 1; p|1 => 1;
1861  // 1|0 => 1; 0|0 => 0; p|0 => p;
1862  // 1|p => 1; 0|p => p; p|p => p;
1863  // S = (S1 & S2) | (~V1 & S2) | (S1 & ~V2)
1864  Value *S1 = getShadow(&I, 0);
1865  Value *S2 = getShadow(&I, 1);
1866  Value *V1 = IRB.CreateNot(I.getOperand(0));
1867  Value *V2 = IRB.CreateNot(I.getOperand(1));
1868  if (V1->getType() != S1->getType()) {
1869  V1 = IRB.CreateIntCast(V1, S1->getType(), false);
1870  V2 = IRB.CreateIntCast(V2, S2->getType(), false);
1871  }
1872  Value *S1S2 = IRB.CreateAnd(S1, S2);
1873  Value *V1S2 = IRB.CreateAnd(V1, S2);
1874  Value *S1V2 = IRB.CreateAnd(S1, V2);
1875  setShadow(&I, IRB.CreateOr(S1S2, IRB.CreateOr(V1S2, S1V2)));
1876  setOriginForNaryOp(I);
1877  }
1878 
1879  /// Default propagation of shadow and/or origin.
1880  ///
1881  /// This class implements the general case of shadow propagation, used in all
1882  /// cases where we don't know and/or don't care about what the operation
1883  /// actually does. It converts all input shadow values to a common type
1884  /// (extending or truncating as necessary), and bitwise OR's them.
1885  ///
1886  /// This is much cheaper than inserting checks (i.e. requiring inputs to be
1887  /// fully initialized), and less prone to false positives.
1888  ///
1889  /// This class also implements the general case of origin propagation. For a
1890  /// Nary operation, result origin is set to the origin of an argument that is
1891  /// not entirely initialized. If there is more than one such arguments, the
1892  /// rightmost of them is picked. It does not matter which one is picked if all
1893  /// arguments are initialized.
1894  template <bool CombineShadow>
1895  class Combiner {
1896  Value *Shadow = nullptr;
1897  Value *Origin = nullptr;
1898  IRBuilder<> &IRB;
1899  MemorySanitizerVisitor *MSV;
1900 
1901  public:
1902  Combiner(MemorySanitizerVisitor *MSV, IRBuilder<> &IRB)
1903  : IRB(IRB), MSV(MSV) {}
1904 
1905  /// Add a pair of shadow and origin values to the mix.
1906  Combiner &Add(Value *OpShadow, Value *OpOrigin) {
1907  if (CombineShadow) {
1908  assert(OpShadow);
1909  if (!Shadow)
1910  Shadow = OpShadow;
1911  else {
1912  OpShadow = MSV->CreateShadowCast(IRB, OpShadow, Shadow->getType());
1913  Shadow = IRB.CreateOr(Shadow, OpShadow, "_msprop");
1914  }
1915  }
1916 
1917  if (MSV->MS.TrackOrigins) {
1918  assert(OpOrigin);
1919  if (!Origin) {
1920  Origin = OpOrigin;
1921  } else {
1922  Constant *ConstOrigin = dyn_cast<Constant>(OpOrigin);
1923  // No point in adding something that might result in 0 origin value.
1924  if (!ConstOrigin || !ConstOrigin->isNullValue()) {
1925  Value *FlatShadow = MSV->convertToShadowTyNoVec(OpShadow, IRB);
1926  Value *Cond =
1927  IRB.CreateICmpNE(FlatShadow, MSV->getCleanShadow(FlatShadow));
1928  Origin = IRB.CreateSelect(Cond, OpOrigin, Origin);
1929  }
1930  }
1931  }
1932  return *this;
1933  }
1934 
1935  /// Add an application value to the mix.
1936  Combiner &Add(Value *V) {
1937  Value *OpShadow = MSV->getShadow(V);
1938  Value *OpOrigin = MSV->MS.TrackOrigins ? MSV->getOrigin(V) : nullptr;
1939  return Add(OpShadow, OpOrigin);
1940  }
1941 
1942  /// Set the current combined values as the given instruction's shadow
1943  /// and origin.
1944  void Done(Instruction *I) {
1945  if (CombineShadow) {
1946  assert(Shadow);
1947  Shadow = MSV->CreateShadowCast(IRB, Shadow, MSV->getShadowTy(I));
1948  MSV->setShadow(I, Shadow);
1949  }
1950  if (MSV->MS.TrackOrigins) {
1951  assert(Origin);
1952  MSV->setOrigin(I, Origin);
1953  }
1954  }
1955  };
1956 
1957  using ShadowAndOriginCombiner = Combiner<true>;
1958  using OriginCombiner = Combiner<false>;
1959 
1960  /// Propagate origin for arbitrary operation.
1961  void setOriginForNaryOp(Instruction &I) {
1962  if (!MS.TrackOrigins) return;
1963  IRBuilder<> IRB(&I);
1964  OriginCombiner OC(this, IRB);
1965  for (Instruction::op_iterator OI = I.op_begin(); OI != I.op_end(); ++OI)
1966  OC.Add(OI->get());
1967  OC.Done(&I);
1968  }
1969 
1970  size_t VectorOrPrimitiveTypeSizeInBits(Type *Ty) {
1971  assert(!(Ty->isVectorTy() && Ty->getScalarType()->isPointerTy()) &&
1972  "Vector of pointers is not a valid shadow type");
1973  return Ty->isVectorTy() ?
1975  Ty->getPrimitiveSizeInBits();
1976  }
1977 
1978  /// Cast between two shadow types, extending or truncating as
1979  /// necessary.
1980  Value *CreateShadowCast(IRBuilder<> &IRB, Value *V, Type *dstTy,
1981  bool Signed = false) {
1982  Type *srcTy = V->getType();
1983  size_t srcSizeInBits = VectorOrPrimitiveTypeSizeInBits(srcTy);
1984  size_t dstSizeInBits = VectorOrPrimitiveTypeSizeInBits(dstTy);
1985  if (srcSizeInBits > 1 && dstSizeInBits == 1)
1986  return IRB.CreateICmpNE(V, getCleanShadow(V));
1987 
1988  if (dstTy->isIntegerTy() && srcTy->isIntegerTy())
1989  return IRB.CreateIntCast(V, dstTy, Signed);
1990  if (dstTy->isVectorTy() && srcTy->isVectorTy() &&
1991  dstTy->getVectorNumElements() == srcTy->getVectorNumElements())
1992  return IRB.CreateIntCast(V, dstTy, Signed);
1993  Value *V1 = IRB.CreateBitCast(V, Type::getIntNTy(*MS.C, srcSizeInBits));
1994  Value *V2 =
1995  IRB.CreateIntCast(V1, Type::getIntNTy(*MS.C, dstSizeInBits), Signed);
1996  return IRB.CreateBitCast(V2, dstTy);
1997  // TODO: handle struct types.
1998  }
1999 
2000  /// Cast an application value to the type of its own shadow.
2001  Value *CreateAppToShadowCast(IRBuilder<> &IRB, Value *V) {
2002  Type *ShadowTy = getShadowTy(V);
2003  if (V->getType() == ShadowTy)
2004  return V;
2005  if (V->getType()->isPtrOrPtrVectorTy())
2006  return IRB.CreatePtrToInt(V, ShadowTy);
2007  else
2008  return IRB.CreateBitCast(V, ShadowTy);
2009  }
2010 
2011  /// Propagate shadow for arbitrary operation.
2012  void handleShadowOr(Instruction &I) {
2013  IRBuilder<> IRB(&I);
2014  ShadowAndOriginCombiner SC(this, IRB);
2015  for (Instruction::op_iterator OI = I.op_begin(); OI != I.op_end(); ++OI)
2016  SC.Add(OI->get());
2017  SC.Done(&I);
2018  }
2019 
2020  // Handle multiplication by constant.
2021  //
2022  // Handle a special case of multiplication by constant that may have one or
2023  // more zeros in the lower bits. This makes corresponding number of lower bits
2024  // of the result zero as well. We model it by shifting the other operand
2025  // shadow left by the required number of bits. Effectively, we transform
2026  // (X * (A * 2**B)) to ((X << B) * A) and instrument (X << B) as (Sx << B).
2027  // We use multiplication by 2**N instead of shift to cover the case of
2028  // multiplication by 0, which may occur in some elements of a vector operand.
2029  void handleMulByConstant(BinaryOperator &I, Constant *ConstArg,
2030  Value *OtherArg) {
2031  Constant *ShadowMul;
2032  Type *Ty = ConstArg->getType();
2033  if (Ty->isVectorTy()) {
2034  unsigned NumElements = Ty->getVectorNumElements();
2035  Type *EltTy = Ty->getSequentialElementType();
2036  SmallVector<Constant *, 16> Elements;
2037  for (unsigned Idx = 0; Idx < NumElements; ++Idx) {
2038  if (ConstantInt *Elt =
2039  dyn_cast<ConstantInt>(ConstArg->getAggregateElement(Idx))) {
2040  const APInt &V = Elt->getValue();
2041  APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
2042  Elements.push_back(ConstantInt::get(EltTy, V2));
2043  } else {
2044  Elements.push_back(ConstantInt::get(EltTy, 1));
2045  }
2046  }
2047  ShadowMul = ConstantVector::get(Elements);
2048  } else {
2049  if (ConstantInt *Elt = dyn_cast<ConstantInt>(ConstArg)) {
2050  const APInt &V = Elt->getValue();
2051  APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
2052  ShadowMul = ConstantInt::get(Ty, V2);
2053  } else {
2054  ShadowMul = ConstantInt::get(Ty, 1);
2055  }
2056  }
2057 
2058  IRBuilder<> IRB(&I);
2059  setShadow(&I,
2060  IRB.CreateMul(getShadow(OtherArg), ShadowMul, "msprop_mul_cst"));
2061  setOrigin(&I, getOrigin(OtherArg));
2062  }
2063 
2064  void visitMul(BinaryOperator &I) {
2065  Constant *constOp0 = dyn_cast<Constant>(I.getOperand(0));
2066  Constant *constOp1 = dyn_cast<Constant>(I.getOperand(1));
2067  if (constOp0 && !constOp1)
2068  handleMulByConstant(I, constOp0, I.getOperand(1));
2069  else if (constOp1 && !constOp0)
2070  handleMulByConstant(I, constOp1, I.getOperand(0));
2071  else
2072  handleShadowOr(I);
2073  }
2074 
2075  void visitFAdd(BinaryOperator &I) { handleShadowOr(I); }
2076  void visitFSub(BinaryOperator &I) { handleShadowOr(I); }
2077  void visitFMul(BinaryOperator &I) { handleShadowOr(I); }
2078  void visitAdd(BinaryOperator &I) { handleShadowOr(I); }
2079  void visitSub(BinaryOperator &I) { handleShadowOr(I); }
2080  void visitXor(BinaryOperator &I) { handleShadowOr(I); }
2081 
2082  void handleIntegerDiv(Instruction &I) {
2083  IRBuilder<> IRB(&I);
2084  // Strict on the second argument.
2085  insertShadowCheck(I.getOperand(1), &I);
2086  setShadow(&I, getShadow(&I, 0));
2087  setOrigin(&I, getOrigin(&I, 0));
2088  }
2089 
2090  void visitUDiv(BinaryOperator &I) { handleIntegerDiv(I); }
2091  void visitSDiv(BinaryOperator &I) { handleIntegerDiv(I); }
2092  void visitURem(BinaryOperator &I) { handleIntegerDiv(I); }
2093  void visitSRem(BinaryOperator &I) { handleIntegerDiv(I); }
2094 
2095  // Floating point division is side-effect free. We can not require that the
2096  // divisor is fully initialized and must propagate shadow. See PR37523.
2097  void visitFDiv(BinaryOperator &I) { handleShadowOr(I); }
2098  void visitFRem(BinaryOperator &I) { handleShadowOr(I); }
2099 
2100  /// Instrument == and != comparisons.
2101  ///
2102  /// Sometimes the comparison result is known even if some of the bits of the
2103  /// arguments are not.
2104  void handleEqualityComparison(ICmpInst &I) {
2105  IRBuilder<> IRB(&I);
2106  Value *A = I.getOperand(0);
2107  Value *B = I.getOperand(1);
2108  Value *Sa = getShadow(A);
2109  Value *Sb = getShadow(B);
2110 
2111  // Get rid of pointers and vectors of pointers.
2112  // For ints (and vectors of ints), types of A and Sa match,
2113  // and this is a no-op.
2114  A = IRB.CreatePointerCast(A, Sa->getType());
2115  B = IRB.CreatePointerCast(B, Sb->getType());
2116 
2117  // A == B <==> (C = A^B) == 0
2118  // A != B <==> (C = A^B) != 0
2119  // Sc = Sa | Sb
2120  Value *C = IRB.CreateXor(A, B);
2121  Value *Sc = IRB.CreateOr(Sa, Sb);
2122  // Now dealing with i = (C == 0) comparison (or C != 0, does not matter now)
2123  // Result is defined if one of the following is true
2124  // * there is a defined 1 bit in C
2125  // * C is fully defined
2126  // Si = !(C & ~Sc) && Sc
2127  Value *Zero = Constant::getNullValue(Sc->getType());
2128  Value *MinusOne = Constant::getAllOnesValue(Sc->getType());
2129  Value *Si =
2130  IRB.CreateAnd(IRB.CreateICmpNE(Sc, Zero),
2131  IRB.CreateICmpEQ(
2132  IRB.CreateAnd(IRB.CreateXor(Sc, MinusOne), C), Zero));
2133  Si->setName("_msprop_icmp");
2134  setShadow(&I, Si);
2135  setOriginForNaryOp(I);
2136  }
2137 
2138  /// Build the lowest possible value of V, taking into account V's
2139  /// uninitialized bits.
2140  Value *getLowestPossibleValue(IRBuilder<> &IRB, Value *A, Value *Sa,
2141  bool isSigned) {
2142  if (isSigned) {
2143  // Split shadow into sign bit and other bits.
2144  Value *SaOtherBits = IRB.CreateLShr(IRB.CreateShl(Sa, 1), 1);
2145  Value *SaSignBit = IRB.CreateXor(Sa, SaOtherBits);
2146  // Maximise the undefined shadow bit, minimize other undefined bits.
2147  return
2148  IRB.CreateOr(IRB.CreateAnd(A, IRB.CreateNot(SaOtherBits)), SaSignBit);
2149  } else {
2150  // Minimize undefined bits.
2151  return IRB.CreateAnd(A, IRB.CreateNot(Sa));
2152  }
2153  }
2154 
2155  /// Build the highest possible value of V, taking into account V's
2156  /// uninitialized bits.
2157  Value *getHighestPossibleValue(IRBuilder<> &IRB, Value *A, Value *Sa,
2158  bool isSigned) {
2159  if (isSigned) {
2160  // Split shadow into sign bit and other bits.
2161  Value *SaOtherBits = IRB.CreateLShr(IRB.CreateShl(Sa, 1), 1);
2162  Value *SaSignBit = IRB.CreateXor(Sa, SaOtherBits);
2163  // Minimise the undefined shadow bit, maximise other undefined bits.
2164  return
2165  IRB.CreateOr(IRB.CreateAnd(A, IRB.CreateNot(SaSignBit)), SaOtherBits);
2166  } else {
2167  // Maximize undefined bits.
2168  return IRB.CreateOr(A, Sa);
2169  }
2170  }
2171 
2172  /// Instrument relational comparisons.
2173  ///
2174  /// This function does exact shadow propagation for all relational
2175  /// comparisons of integers, pointers and vectors of those.
2176  /// FIXME: output seems suboptimal when one of the operands is a constant
2177  void handleRelationalComparisonExact(ICmpInst &I) {
2178  IRBuilder<> IRB(&I);
2179  Value *A = I.getOperand(0);
2180  Value *B = I.getOperand(1);
2181  Value *Sa = getShadow(A);
2182  Value *Sb = getShadow(B);
2183 
2184  // Get rid of pointers and vectors of pointers.
2185  // For ints (and vectors of ints), types of A and Sa match,
2186  // and this is a no-op.
2187  A = IRB.CreatePointerCast(A, Sa->getType());
2188  B = IRB.CreatePointerCast(B, Sb->getType());
2189 
2190  // Let [a0, a1] be the interval of possible values of A, taking into account
2191  // its undefined bits. Let [b0, b1] be the interval of possible values of B.
2192  // Then (A cmp B) is defined iff (a0 cmp b1) == (a1 cmp b0).
2193  bool IsSigned = I.isSigned();
2194  Value *S1 = IRB.CreateICmp(I.getPredicate(),
2195  getLowestPossibleValue(IRB, A, Sa, IsSigned),
2196  getHighestPossibleValue(IRB, B, Sb, IsSigned));
2197  Value *S2 = IRB.CreateICmp(I.getPredicate(),
2198  getHighestPossibleValue(IRB, A, Sa, IsSigned),
2199  getLowestPossibleValue(IRB, B, Sb, IsSigned));
2200  Value *Si = IRB.CreateXor(S1, S2);
2201  setShadow(&I, Si);
2202  setOriginForNaryOp(I);
2203  }
2204 
2205  /// Instrument signed relational comparisons.
2206  ///
2207  /// Handle sign bit tests: x<0, x>=0, x<=-1, x>-1 by propagating the highest
2208  /// bit of the shadow. Everything else is delegated to handleShadowOr().
2209  void handleSignedRelationalComparison(ICmpInst &I) {
2210  Constant *constOp;
2211  Value *op = nullptr;
2212  CmpInst::Predicate pre;
2213  if ((constOp = dyn_cast<Constant>(I.getOperand(1)))) {
2214  op = I.getOperand(0);
2215  pre = I.getPredicate();
2216  } else if ((constOp = dyn_cast<Constant>(I.getOperand(0)))) {
2217  op = I.getOperand(1);
2218  pre = I.getSwappedPredicate();
2219  } else {
2220  handleShadowOr(I);
2221  return;
2222  }
2223 
2224  if ((constOp->isNullValue() &&
2225  (pre == CmpInst::ICMP_SLT || pre == CmpInst::ICMP_SGE)) ||
2226  (constOp->isAllOnesValue() &&
2227  (pre == CmpInst::ICMP_SGT || pre == CmpInst::ICMP_SLE))) {
2228  IRBuilder<> IRB(&I);
2229  Value *Shadow = IRB.CreateICmpSLT(getShadow(op), getCleanShadow(op),
2230  "_msprop_icmp_s");
2231  setShadow(&I, Shadow);
2232  setOrigin(&I, getOrigin(op));
2233  } else {
2234  handleShadowOr(I);
2235  }
2236  }
2237 
2238  void visitICmpInst(ICmpInst &I) {
2239  if (!ClHandleICmp) {
2240  handleShadowOr(I);
2241  return;
2242  }
2243  if (I.isEquality()) {
2244  handleEqualityComparison(I);
2245  return;
2246  }
2247 
2248  assert(I.isRelational());
2249  if (ClHandleICmpExact) {
2250  handleRelationalComparisonExact(I);
2251  return;
2252  }
2253  if (I.isSigned()) {
2254  handleSignedRelationalComparison(I);
2255  return;
2256  }
2257 
2258  assert(I.isUnsigned());
2259  if ((isa<Constant>(I.getOperand(0)) || isa<Constant>(I.getOperand(1)))) {
2260  handleRelationalComparisonExact(I);
2261  return;
2262  }
2263 
2264  handleShadowOr(I);
2265  }
2266 
2267  void visitFCmpInst(FCmpInst &I) {
2268  handleShadowOr(I);
2269  }
2270 
2271  void handleShift(BinaryOperator &I) {
2272  IRBuilder<> IRB(&I);
2273  // If any of the S2 bits are poisoned, the whole thing is poisoned.
2274  // Otherwise perform the same shift on S1.
2275  Value *S1 = getShadow(&I, 0);
2276  Value *S2 = getShadow(&I, 1);
2277  Value *S2Conv = IRB.CreateSExt(IRB.CreateICmpNE(S2, getCleanShadow(S2)),
2278  S2->getType());
2279  Value *V2 = I.getOperand(1);
2280  Value *Shift = IRB.CreateBinOp(I.getOpcode(), S1, V2);
2281  setShadow(&I, IRB.CreateOr(Shift, S2Conv));
2282  setOriginForNaryOp(I);
2283  }
2284 
2285  void visitShl(BinaryOperator &I) { handleShift(I); }
2286  void visitAShr(BinaryOperator &I) { handleShift(I); }
2287  void visitLShr(BinaryOperator &I) { handleShift(I); }
2288 
2289  /// Instrument llvm.memmove
2290  ///
2291  /// At this point we don't know if llvm.memmove will be inlined or not.
2292  /// If we don't instrument it and it gets inlined,
2293  /// our interceptor will not kick in and we will lose the memmove.
2294  /// If we instrument the call here, but it does not get inlined,
2295  /// we will memove the shadow twice: which is bad in case
2296  /// of overlapping regions. So, we simply lower the intrinsic to a call.
2297  ///
2298  /// Similar situation exists for memcpy and memset.
2299  void visitMemMoveInst(MemMoveInst &I) {
2300  IRBuilder<> IRB(&I);
2301  IRB.CreateCall(
2302  MS.MemmoveFn,
2303  {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()),
2304  IRB.CreatePointerCast(I.getArgOperand(1), IRB.getInt8PtrTy()),
2305  IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)});
2306  I.eraseFromParent();
2307  }
2308 
2309  // Similar to memmove: avoid copying shadow twice.
2310  // This is somewhat unfortunate as it may slowdown small constant memcpys.
2311  // FIXME: consider doing manual inline for small constant sizes and proper
2312  // alignment.
2313  void visitMemCpyInst(MemCpyInst &I) {
2314  IRBuilder<> IRB(&I);
2315  IRB.CreateCall(
2316  MS.MemcpyFn,
2317  {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()),
2318  IRB.CreatePointerCast(I.getArgOperand(1), IRB.getInt8PtrTy()),
2319  IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)});
2320  I.eraseFromParent();
2321  }
2322 
2323  // Same as memcpy.
2324  void visitMemSetInst(MemSetInst &I) {
2325  IRBuilder<> IRB(&I);
2326  IRB.CreateCall(
2327  MS.MemsetFn,
2328  {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()),
2329  IRB.CreateIntCast(I.getArgOperand(1), IRB.getInt32Ty(), false),
2330  IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)});
2331  I.eraseFromParent();
2332  }
2333 
2334  void visitVAStartInst(VAStartInst &I) {
2335  VAHelper->visitVAStartInst(I);
2336  }
2337 
2338  void visitVACopyInst(VACopyInst &I) {
2339  VAHelper->visitVACopyInst(I);
2340  }
2341 
2342  /// Handle vector store-like intrinsics.
2343  ///
2344  /// Instrument intrinsics that look like a simple SIMD store: writes memory,
2345  /// has 1 pointer argument and 1 vector argument, returns void.
2346  bool handleVectorStoreIntrinsic(IntrinsicInst &I) {
2347  IRBuilder<> IRB(&I);
2348  Value* Addr = I.getArgOperand(0);
2349  Value *Shadow = getShadow(&I, 1);
2350  Value *ShadowPtr, *OriginPtr;
2351 
2352  // We don't know the pointer alignment (could be unaligned SSE store!).
2353  // Have to assume to worst case.
2354  std::tie(ShadowPtr, OriginPtr) = getShadowOriginPtr(
2355  Addr, IRB, Shadow->getType(), /*Alignment*/ 1, /*isStore*/ true);
2356  IRB.CreateAlignedStore(Shadow, ShadowPtr, 1);
2357 
2359  insertShadowCheck(Addr, &I);
2360 
2361  // FIXME: factor out common code from materializeStores
2362  if (MS.TrackOrigins) IRB.CreateStore(getOrigin(&I, 1), OriginPtr);
2363  return true;
2364  }
2365 
2366  /// Handle vector load-like intrinsics.
2367  ///
2368  /// Instrument intrinsics that look like a simple SIMD load: reads memory,
2369  /// has 1 pointer argument, returns a vector.
2370  bool handleVectorLoadIntrinsic(IntrinsicInst &I) {
2371  IRBuilder<> IRB(&I);
2372  Value *Addr = I.getArgOperand(0);
2373 
2374  Type *ShadowTy = getShadowTy(&I);
2375  Value *ShadowPtr, *OriginPtr;
2376  if (PropagateShadow) {
2377  // We don't know the pointer alignment (could be unaligned SSE load!).
2378  // Have to assume to worst case.
2379  unsigned Alignment = 1;
2380  std::tie(ShadowPtr, OriginPtr) =
2381  getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false);
2382  setShadow(&I, IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_msld"));
2383  } else {
2384  setShadow(&I, getCleanShadow(&I));
2385  }
2386 
2388  insertShadowCheck(Addr, &I);
2389 
2390  if (MS.TrackOrigins) {
2391  if (PropagateShadow)
2392  setOrigin(&I, IRB.CreateLoad(OriginPtr));
2393  else
2394  setOrigin(&I, getCleanOrigin());
2395  }
2396  return true;
2397  }
2398 
2399  /// Handle (SIMD arithmetic)-like intrinsics.
2400  ///
2401  /// Instrument intrinsics with any number of arguments of the same type,
2402  /// equal to the return type. The type should be simple (no aggregates or
2403  /// pointers; vectors are fine).
2404  /// Caller guarantees that this intrinsic does not access memory.
2405  bool maybeHandleSimpleNomemIntrinsic(IntrinsicInst &I) {
2406  Type *RetTy = I.getType();
2407  if (!(RetTy->isIntOrIntVectorTy() ||
2408  RetTy->isFPOrFPVectorTy() ||
2409  RetTy->isX86_MMXTy()))
2410  return false;
2411 
2412  unsigned NumArgOperands = I.getNumArgOperands();
2413 
2414  for (unsigned i = 0; i < NumArgOperands; ++i) {
2415  Type *Ty = I.getArgOperand(i)->getType();
2416  if (Ty != RetTy)
2417  return false;
2418  }
2419 
2420  IRBuilder<> IRB(&I);
2421  ShadowAndOriginCombiner SC(this, IRB);
2422  for (unsigned i = 0; i < NumArgOperands; ++i)
2423  SC.Add(I.getArgOperand(i));
2424  SC.Done(&I);
2425 
2426  return true;
2427  }
2428 
2429  /// Heuristically instrument unknown intrinsics.
2430  ///
2431  /// The main purpose of this code is to do something reasonable with all
2432  /// random intrinsics we might encounter, most importantly - SIMD intrinsics.
2433  /// We recognize several classes of intrinsics by their argument types and
2434  /// ModRefBehaviour and apply special intrumentation when we are reasonably
2435  /// sure that we know what the intrinsic does.
2436  ///
2437  /// We special-case intrinsics where this approach fails. See llvm.bswap
2438  /// handling as an example of that.
2439  bool handleUnknownIntrinsic(IntrinsicInst &I) {
2440  unsigned NumArgOperands = I.getNumArgOperands();
2441  if (NumArgOperands == 0)
2442  return false;
2443 
2444  if (NumArgOperands == 2 &&
2445  I.getArgOperand(0)->getType()->isPointerTy() &&
2446  I.getArgOperand(1)->getType()->isVectorTy() &&
2447  I.getType()->isVoidTy() &&
2448  !I.onlyReadsMemory()) {
2449  // This looks like a vector store.
2450  return handleVectorStoreIntrinsic(I);
2451  }
2452 
2453  if (NumArgOperands == 1 &&
2454  I.getArgOperand(0)->getType()->isPointerTy() &&
2455  I.getType()->isVectorTy() &&
2456  I.onlyReadsMemory()) {
2457  // This looks like a vector load.
2458  return handleVectorLoadIntrinsic(I);
2459  }
2460 
2461  if (I.doesNotAccessMemory())
2462  if (maybeHandleSimpleNomemIntrinsic(I))
2463  return true;
2464 
2465  // FIXME: detect and handle SSE maskstore/maskload
2466  return false;
2467  }
2468 
2469  void handleBswap(IntrinsicInst &I) {
2470  IRBuilder<> IRB(&I);
2471  Value *Op = I.getArgOperand(0);
2472  Type *OpType = Op->getType();
2473  Function *BswapFunc = Intrinsic::getDeclaration(
2474  F.getParent(), Intrinsic::bswap, makeArrayRef(&OpType, 1));
2475  setShadow(&I, IRB.CreateCall(BswapFunc, getShadow(Op)));
2476  setOrigin(&I, getOrigin(Op));
2477  }
2478 
2479  // Instrument vector convert instrinsic.
2480  //
2481  // This function instruments intrinsics like cvtsi2ss:
2482  // %Out = int_xxx_cvtyyy(%ConvertOp)
2483  // or
2484  // %Out = int_xxx_cvtyyy(%CopyOp, %ConvertOp)
2485  // Intrinsic converts \p NumUsedElements elements of \p ConvertOp to the same
2486  // number \p Out elements, and (if has 2 arguments) copies the rest of the
2487  // elements from \p CopyOp.
2488  // In most cases conversion involves floating-point value which may trigger a
2489  // hardware exception when not fully initialized. For this reason we require
2490  // \p ConvertOp[0:NumUsedElements] to be fully initialized and trap otherwise.
2491  // We copy the shadow of \p CopyOp[NumUsedElements:] to \p
2492  // Out[NumUsedElements:]. This means that intrinsics without \p CopyOp always
2493  // return a fully initialized value.
2494  void handleVectorConvertIntrinsic(IntrinsicInst &I, int NumUsedElements) {
2495  IRBuilder<> IRB(&I);
2496  Value *CopyOp, *ConvertOp;
2497 
2498  switch (I.getNumArgOperands()) {
2499  case 3:
2500  assert(isa<ConstantInt>(I.getArgOperand(2)) && "Invalid rounding mode");
2502  case 2:
2503  CopyOp = I.getArgOperand(0);
2504  ConvertOp = I.getArgOperand(1);
2505  break;
2506  case 1:
2507  ConvertOp = I.getArgOperand(0);
2508  CopyOp = nullptr;
2509  break;
2510  default:
2511  llvm_unreachable("Cvt intrinsic with unsupported number of arguments.");
2512  }
2513 
2514  // The first *NumUsedElements* elements of ConvertOp are converted to the
2515  // same number of output elements. The rest of the output is copied from
2516  // CopyOp, or (if not available) filled with zeroes.
2517  // Combine shadow for elements of ConvertOp that are used in this operation,
2518  // and insert a check.
2519  // FIXME: consider propagating shadow of ConvertOp, at least in the case of
2520  // int->any conversion.
2521  Value *ConvertShadow = getShadow(ConvertOp);
2522  Value *AggShadow = nullptr;
2523  if (ConvertOp->getType()->isVectorTy()) {
2524  AggShadow = IRB.CreateExtractElement(
2525  ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), 0));
2526  for (int i = 1; i < NumUsedElements; ++i) {
2527  Value *MoreShadow = IRB.CreateExtractElement(
2528  ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), i));
2529  AggShadow = IRB.CreateOr(AggShadow, MoreShadow);
2530  }
2531  } else {
2532  AggShadow = ConvertShadow;
2533  }
2534  assert(AggShadow->getType()->isIntegerTy());
2535  insertShadowCheck(AggShadow, getOrigin(ConvertOp), &I);
2536 
2537  // Build result shadow by zero-filling parts of CopyOp shadow that come from
2538  // ConvertOp.
2539  if (CopyOp) {
2540  assert(CopyOp->getType() == I.getType());
2541  assert(CopyOp->getType()->isVectorTy());
2542  Value *ResultShadow = getShadow(CopyOp);
2543  Type *EltTy = ResultShadow->getType()->getVectorElementType();
2544  for (int i = 0; i < NumUsedElements; ++i) {
2545  ResultShadow = IRB.CreateInsertElement(
2546  ResultShadow, ConstantInt::getNullValue(EltTy),
2547  ConstantInt::get(IRB.getInt32Ty(), i));
2548  }
2549  setShadow(&I, ResultShadow);
2550  setOrigin(&I, getOrigin(CopyOp));
2551  } else {
2552  setShadow(&I, getCleanShadow(&I));
2553  setOrigin(&I, getCleanOrigin());
2554  }
2555  }
2556 
2557  // Given a scalar or vector, extract lower 64 bits (or less), and return all
2558  // zeroes if it is zero, and all ones otherwise.
2559  Value *Lower64ShadowExtend(IRBuilder<> &IRB, Value *S, Type *T) {
2560  if (S->getType()->isVectorTy())
2561  S = CreateShadowCast(IRB, S, IRB.getInt64Ty(), /* Signed */ true);
2562  assert(S->getType()->getPrimitiveSizeInBits() <= 64);
2563  Value *S2 = IRB.CreateICmpNE(S, getCleanShadow(S));
2564  return CreateShadowCast(IRB, S2, T, /* Signed */ true);
2565  }
2566 
2567  // Given a vector, extract its first element, and return all
2568  // zeroes if it is zero, and all ones otherwise.
2569  Value *LowerElementShadowExtend(IRBuilder<> &IRB, Value *S, Type *T) {
2570  Value *S1 = IRB.CreateExtractElement(S, (uint64_t)0);
2571  Value *S2 = IRB.CreateICmpNE(S1, getCleanShadow(S1));
2572  return CreateShadowCast(IRB, S2, T, /* Signed */ true);
2573  }
2574 
2575  Value *VariableShadowExtend(IRBuilder<> &IRB, Value *S) {
2576  Type *T = S->getType();
2577  assert(T->isVectorTy());
2578  Value *S2 = IRB.CreateICmpNE(S, getCleanShadow(S));
2579  return IRB.CreateSExt(S2, T);
2580  }
2581 
2582  // Instrument vector shift instrinsic.
2583  //
2584  // This function instruments intrinsics like int_x86_avx2_psll_w.
2585  // Intrinsic shifts %In by %ShiftSize bits.
2586  // %ShiftSize may be a vector. In that case the lower 64 bits determine shift
2587  // size, and the rest is ignored. Behavior is defined even if shift size is
2588  // greater than register (or field) width.
2589  void handleVectorShiftIntrinsic(IntrinsicInst &I, bool Variable) {
2590  assert(I.getNumArgOperands() == 2);
2591  IRBuilder<> IRB(&I);
2592  // If any of the S2 bits are poisoned, the whole thing is poisoned.
2593  // Otherwise perform the same shift on S1.
2594  Value *S1 = getShadow(&I, 0);
2595  Value *S2 = getShadow(&I, 1);
2596  Value *S2Conv = Variable ? VariableShadowExtend(IRB, S2)
2597  : Lower64ShadowExtend(IRB, S2, getShadowTy(&I));
2598  Value *V1 = I.getOperand(0);
2599  Value *V2 = I.getOperand(1);
2600  Value *Shift = IRB.CreateCall(I.getCalledValue(),
2601  {IRB.CreateBitCast(S1, V1->getType()), V2});
2602  Shift = IRB.CreateBitCast(Shift, getShadowTy(&I));
2603  setShadow(&I, IRB.CreateOr(Shift, S2Conv));
2604  setOriginForNaryOp(I);
2605  }
2606 
2607  // Get an X86_MMX-sized vector type.
2608  Type *getMMXVectorTy(unsigned EltSizeInBits) {
2609  const unsigned X86_MMXSizeInBits = 64;
2610  return VectorType::get(IntegerType::get(*MS.C, EltSizeInBits),
2611  X86_MMXSizeInBits / EltSizeInBits);
2612  }
2613 
2614  // Returns a signed counterpart for an (un)signed-saturate-and-pack
2615  // intrinsic.
2616  Intrinsic::ID getSignedPackIntrinsic(Intrinsic::ID id) {
2617  switch (id) {
2618  case Intrinsic::x86_sse2_packsswb_128:
2619  case Intrinsic::x86_sse2_packuswb_128:
2620  return Intrinsic::x86_sse2_packsswb_128;
2621 
2622  case Intrinsic::x86_sse2_packssdw_128:
2623  case Intrinsic::x86_sse41_packusdw:
2624  return Intrinsic::x86_sse2_packssdw_128;
2625 
2626  case Intrinsic::x86_avx2_packsswb:
2627  case Intrinsic::x86_avx2_packuswb:
2628  return Intrinsic::x86_avx2_packsswb;
2629 
2630  case Intrinsic::x86_avx2_packssdw:
2631  case Intrinsic::x86_avx2_packusdw:
2632  return Intrinsic::x86_avx2_packssdw;
2633 
2634  case Intrinsic::x86_mmx_packsswb:
2635  case Intrinsic::x86_mmx_packuswb:
2636  return Intrinsic::x86_mmx_packsswb;
2637 
2638  case Intrinsic::x86_mmx_packssdw:
2639  return Intrinsic::x86_mmx_packssdw;
2640  default:
2641  llvm_unreachable("unexpected intrinsic id");
2642  }
2643  }
2644 
2645  // Instrument vector pack instrinsic.
2646  //
2647  // This function instruments intrinsics like x86_mmx_packsswb, that
2648  // packs elements of 2 input vectors into half as many bits with saturation.
2649  // Shadow is propagated with the signed variant of the same intrinsic applied
2650  // to sext(Sa != zeroinitializer), sext(Sb != zeroinitializer).
2651  // EltSizeInBits is used only for x86mmx arguments.
2652  void handleVectorPackIntrinsic(IntrinsicInst &I, unsigned EltSizeInBits = 0) {
2653  assert(I.getNumArgOperands() == 2);
2654  bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
2655  IRBuilder<> IRB(&I);
2656  Value *S1 = getShadow(&I, 0);
2657  Value *S2 = getShadow(&I, 1);
2658  assert(isX86_MMX || S1->getType()->isVectorTy());
2659 
2660  // SExt and ICmpNE below must apply to individual elements of input vectors.
2661  // In case of x86mmx arguments, cast them to appropriate vector types and
2662  // back.
2663  Type *T = isX86_MMX ? getMMXVectorTy(EltSizeInBits) : S1->getType();
2664  if (isX86_MMX) {
2665  S1 = IRB.CreateBitCast(S1, T);
2666  S2 = IRB.CreateBitCast(S2, T);
2667  }
2668  Value *S1_ext = IRB.CreateSExt(
2669  IRB.CreateICmpNE(S1, Constant::getNullValue(T)), T);
2670  Value *S2_ext = IRB.CreateSExt(
2671  IRB.CreateICmpNE(S2, Constant::getNullValue(T)), T);
2672  if (isX86_MMX) {
2673  Type *X86_MMXTy = Type::getX86_MMXTy(*MS.C);
2674  S1_ext = IRB.CreateBitCast(S1_ext, X86_MMXTy);
2675  S2_ext = IRB.CreateBitCast(S2_ext, X86_MMXTy);
2676  }
2677 
2678  Function *ShadowFn = Intrinsic::getDeclaration(
2679  F.getParent(), getSignedPackIntrinsic(I.getIntrinsicID()));
2680 
2681  Value *S =
2682  IRB.CreateCall(ShadowFn, {S1_ext, S2_ext}, "_msprop_vector_pack");
2683  if (isX86_MMX) S = IRB.CreateBitCast(S, getShadowTy(&I));
2684  setShadow(&I, S);
2685  setOriginForNaryOp(I);
2686  }
2687 
2688  // Instrument sum-of-absolute-differencies intrinsic.
2689  void handleVectorSadIntrinsic(IntrinsicInst &I) {
2690  const unsigned SignificantBitsPerResultElement = 16;
2691  bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
2692  Type *ResTy = isX86_MMX ? IntegerType::get(*MS.C, 64) : I.getType();
2693  unsigned ZeroBitsPerResultElement =
2694  ResTy->getScalarSizeInBits() - SignificantBitsPerResultElement;
2695 
2696  IRBuilder<> IRB(&I);
2697  Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2698  S = IRB.CreateBitCast(S, ResTy);
2699  S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)),
2700  ResTy);
2701  S = IRB.CreateLShr(S, ZeroBitsPerResultElement);
2702  S = IRB.CreateBitCast(S, getShadowTy(&I));
2703  setShadow(&I, S);
2704  setOriginForNaryOp(I);
2705  }
2706 
2707  // Instrument multiply-add intrinsic.
2708  void handleVectorPmaddIntrinsic(IntrinsicInst &I,
2709  unsigned EltSizeInBits = 0) {
2710  bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
2711  Type *ResTy = isX86_MMX ? getMMXVectorTy(EltSizeInBits * 2) : I.getType();
2712  IRBuilder<> IRB(&I);
2713  Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2714  S = IRB.CreateBitCast(S, ResTy);
2715  S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)),
2716  ResTy);
2717  S = IRB.CreateBitCast(S, getShadowTy(&I));
2718  setShadow(&I, S);
2719  setOriginForNaryOp(I);
2720  }
2721 
2722  // Instrument compare-packed intrinsic.
2723  // Basically, an or followed by sext(icmp ne 0) to end up with all-zeros or
2724  // all-ones shadow.
2725  void handleVectorComparePackedIntrinsic(IntrinsicInst &I) {
2726  IRBuilder<> IRB(&I);
2727  Type *ResTy = getShadowTy(&I);
2728  Value *S0 = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2729  Value *S = IRB.CreateSExt(
2730  IRB.CreateICmpNE(S0, Constant::getNullValue(ResTy)), ResTy);
2731  setShadow(&I, S);
2732  setOriginForNaryOp(I);
2733  }
2734 
2735  // Instrument compare-scalar intrinsic.
2736  // This handles both cmp* intrinsics which return the result in the first
2737  // element of a vector, and comi* which return the result as i32.
2738  void handleVectorCompareScalarIntrinsic(IntrinsicInst &I) {
2739  IRBuilder<> IRB(&I);
2740  Value *S0 = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2741  Value *S = LowerElementShadowExtend(IRB, S0, getShadowTy(&I));
2742  setShadow(&I, S);
2743  setOriginForNaryOp(I);
2744  }
2745 
2746  void handleStmxcsr(IntrinsicInst &I) {
2747  IRBuilder<> IRB(&I);
2748  Value* Addr = I.getArgOperand(0);
2749  Type *Ty = IRB.getInt32Ty();
2750  Value *ShadowPtr =
2751  getShadowOriginPtr(Addr, IRB, Ty, /*Alignment*/ 1, /*isStore*/ true)
2752  .first;
2753 
2754  IRB.CreateStore(getCleanShadow(Ty),
2755  IRB.CreatePointerCast(ShadowPtr, Ty->getPointerTo()));
2756 
2758  insertShadowCheck(Addr, &I);
2759  }
2760 
2761  void handleLdmxcsr(IntrinsicInst &I) {
2762  if (!InsertChecks) return;
2763 
2764  IRBuilder<> IRB(&I);
2765  Value *Addr = I.getArgOperand(0);
2766  Type *Ty = IRB.getInt32Ty();
2767  unsigned Alignment = 1;
2768  Value *ShadowPtr, *OriginPtr;
2769  std::tie(ShadowPtr, OriginPtr) =
2770  getShadowOriginPtr(Addr, IRB, Ty, Alignment, /*isStore*/ false);
2771 
2773  insertShadowCheck(Addr, &I);
2774 
2775  Value *Shadow = IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_ldmxcsr");
2776  Value *Origin =
2777  MS.TrackOrigins ? IRB.CreateLoad(OriginPtr) : getCleanOrigin();
2778  insertShadowCheck(Shadow, Origin, &I);
2779  }
2780 
2781  void handleMaskedStore(IntrinsicInst &I) {
2782  IRBuilder<> IRB(&I);
2783  Value *V = I.getArgOperand(0);
2784  Value *Addr = I.getArgOperand(1);
2785  unsigned Align = cast<ConstantInt>(I.getArgOperand(2))->getZExtValue();
2786  Value *Mask = I.getArgOperand(3);
2787  Value *Shadow = getShadow(V);
2788 
2789  Value *ShadowPtr;
2790  Value *OriginPtr;
2791  std::tie(ShadowPtr, OriginPtr) = getShadowOriginPtr(
2792  Addr, IRB, Shadow->getType(), Align, /*isStore*/ true);
2793 
2794  if (ClCheckAccessAddress) {
2795  insertShadowCheck(Addr, &I);
2796  // Uninitialized mask is kind of like uninitialized address, but not as
2797  // scary.
2798  insertShadowCheck(Mask, &I);
2799  }
2800 
2801  IRB.CreateMaskedStore(Shadow, ShadowPtr, Align, Mask);
2802 
2803  if (MS.TrackOrigins) {
2804  auto &DL = F.getParent()->getDataLayout();
2805  paintOrigin(IRB, getOrigin(V), OriginPtr,
2806  DL.getTypeStoreSize(Shadow->getType()),
2807  std::max(Align, kMinOriginAlignment));
2808  }
2809  }
2810 
2811  bool handleMaskedLoad(IntrinsicInst &I) {
2812  IRBuilder<> IRB(&I);
2813  Value *Addr = I.getArgOperand(0);
2814  unsigned Align = cast<ConstantInt>(I.getArgOperand(1))->getZExtValue();
2815  Value *Mask = I.getArgOperand(2);
2816  Value *PassThru = I.getArgOperand(3);
2817 
2818  Type *ShadowTy = getShadowTy(&I);
2819  Value *ShadowPtr, *OriginPtr;
2820  if (PropagateShadow) {
2821  std::tie(ShadowPtr, OriginPtr) =
2822  getShadowOriginPtr(Addr, IRB, ShadowTy, Align, /*isStore*/ false);
2823  setShadow(&I, IRB.CreateMaskedLoad(ShadowPtr, Align, Mask,
2824  getShadow(PassThru), "_msmaskedld"));
2825  } else {
2826  setShadow(&I, getCleanShadow(&I));
2827  }
2828 
2829  if (ClCheckAccessAddress) {
2830  insertShadowCheck(Addr, &I);
2831  insertShadowCheck(Mask, &I);
2832  }
2833 
2834  if (MS.TrackOrigins) {
2835  if (PropagateShadow) {
2836  // Choose between PassThru's and the loaded value's origins.
2837  Value *MaskedPassThruShadow = IRB.CreateAnd(
2838  getShadow(PassThru), IRB.CreateSExt(IRB.CreateNeg(Mask), ShadowTy));
2839 
2840  Value *Acc = IRB.CreateExtractElement(
2841  MaskedPassThruShadow, ConstantInt::get(IRB.getInt32Ty(), 0));
2842  for (int i = 1, N = PassThru->getType()->getVectorNumElements(); i < N;
2843  ++i) {
2844  Value *More = IRB.CreateExtractElement(
2845  MaskedPassThruShadow, ConstantInt::get(IRB.getInt32Ty(), i));
2846  Acc = IRB.CreateOr(Acc, More);
2847  }
2848 
2849  Value *Origin = IRB.CreateSelect(
2850  IRB.CreateICmpNE(Acc, Constant::getNullValue(Acc->getType())),
2851  getOrigin(PassThru), IRB.CreateLoad(OriginPtr));
2852 
2853  setOrigin(&I, Origin);
2854  } else {
2855  setOrigin(&I, getCleanOrigin());
2856  }
2857  }
2858  return true;
2859  }
2860 
2861 
2862  void visitIntrinsicInst(IntrinsicInst &I) {
2863  switch (I.getIntrinsicID()) {
2864  case Intrinsic::bswap:
2865  handleBswap(I);
2866  break;
2867  case Intrinsic::masked_store:
2868  handleMaskedStore(I);
2869  break;
2870  case Intrinsic::masked_load:
2871  handleMaskedLoad(I);
2872  break;
2873  case Intrinsic::x86_sse_stmxcsr:
2874  handleStmxcsr(I);
2875  break;
2876  case Intrinsic::x86_sse_ldmxcsr:
2877  handleLdmxcsr(I);
2878  break;
2879  case Intrinsic::x86_avx512_vcvtsd2usi64:
2880  case Intrinsic::x86_avx512_vcvtsd2usi32:
2881  case Intrinsic::x86_avx512_vcvtss2usi64:
2882  case Intrinsic::x86_avx512_vcvtss2usi32:
2883  case Intrinsic::x86_avx512_cvttss2usi64:
2884  case Intrinsic::x86_avx512_cvttss2usi:
2885  case Intrinsic::x86_avx512_cvttsd2usi64:
2886  case Intrinsic::x86_avx512_cvttsd2usi:
2887  case Intrinsic::x86_avx512_cvtusi2ss:
2888  case Intrinsic::x86_avx512_cvtusi642sd:
2889  case Intrinsic::x86_avx512_cvtusi642ss:
2890  case Intrinsic::x86_sse2_cvtsd2si64:
2891  case Intrinsic::x86_sse2_cvtsd2si:
2892  case Intrinsic::x86_sse2_cvtsd2ss:
2893  case Intrinsic::x86_sse2_cvttsd2si64:
2894  case Intrinsic::x86_sse2_cvttsd2si:
2895  case Intrinsic::x86_sse_cvtss2si64:
2896  case Intrinsic::x86_sse_cvtss2si:
2897  case Intrinsic::x86_sse_cvttss2si64:
2898  case Intrinsic::x86_sse_cvttss2si:
2899  handleVectorConvertIntrinsic(I, 1);
2900  break;
2901  case Intrinsic::x86_sse_cvtps2pi:
2902  case Intrinsic::x86_sse_cvttps2pi:
2903  handleVectorConvertIntrinsic(I, 2);
2904  break;
2905 
2906  case Intrinsic::x86_avx512_psll_w_512:
2907  case Intrinsic::x86_avx512_psll_d_512:
2908  case Intrinsic::x86_avx512_psll_q_512:
2909  case Intrinsic::x86_avx512_pslli_w_512:
2910  case Intrinsic::x86_avx512_pslli_d_512:
2911  case Intrinsic::x86_avx512_pslli_q_512:
2912  case Intrinsic::x86_avx512_psrl_w_512:
2913  case Intrinsic::x86_avx512_psrl_d_512:
2914  case Intrinsic::x86_avx512_psrl_q_512:
2915  case Intrinsic::x86_avx512_psra_w_512:
2916  case Intrinsic::x86_avx512_psra_d_512:
2917  case Intrinsic::x86_avx512_psra_q_512:
2918  case Intrinsic::x86_avx512_psrli_w_512:
2919  case Intrinsic::x86_avx512_psrli_d_512:
2920  case Intrinsic::x86_avx512_psrli_q_512:
2921  case Intrinsic::x86_avx512_psrai_w_512:
2922  case Intrinsic::x86_avx512_psrai_d_512:
2923  case Intrinsic::x86_avx512_psrai_q_512:
2924  case Intrinsic::x86_avx512_psra_q_256:
2925  case Intrinsic::x86_avx512_psra_q_128:
2926  case Intrinsic::x86_avx512_psrai_q_256:
2927  case Intrinsic::x86_avx512_psrai_q_128:
2928  case Intrinsic::x86_avx2_psll_w:
2929  case Intrinsic::x86_avx2_psll_d:
2930  case Intrinsic::x86_avx2_psll_q:
2931  case Intrinsic::x86_avx2_pslli_w:
2932  case Intrinsic::x86_avx2_pslli_d:
2933  case Intrinsic::x86_avx2_pslli_q:
2934  case Intrinsic::x86_avx2_psrl_w:
2935  case Intrinsic::x86_avx2_psrl_d:
2936  case Intrinsic::x86_avx2_psrl_q:
2937  case Intrinsic::x86_avx2_psra_w:
2938  case Intrinsic::x86_avx2_psra_d:
2939  case Intrinsic::x86_avx2_psrli_w:
2940  case Intrinsic::x86_avx2_psrli_d:
2941  case Intrinsic::x86_avx2_psrli_q:
2942  case Intrinsic::x86_avx2_psrai_w:
2943  case Intrinsic::x86_avx2_psrai_d:
2944  case Intrinsic::x86_sse2_psll_w:
2945  case Intrinsic::x86_sse2_psll_d:
2946  case Intrinsic::x86_sse2_psll_q:
2947  case Intrinsic::x86_sse2_pslli_w:
2948  case Intrinsic::x86_sse2_pslli_d:
2949  case Intrinsic::x86_sse2_pslli_q:
2950  case Intrinsic::x86_sse2_psrl_w:
2951  case Intrinsic::x86_sse2_psrl_d:
2952  case Intrinsic::x86_sse2_psrl_q:
2953  case Intrinsic::x86_sse2_psra_w:
2954  case Intrinsic::x86_sse2_psra_d:
2955  case Intrinsic::x86_sse2_psrli_w:
2956  case Intrinsic::x86_sse2_psrli_d:
2957  case Intrinsic::x86_sse2_psrli_q:
2958  case Intrinsic::x86_sse2_psrai_w:
2959  case Intrinsic::x86_sse2_psrai_d:
2960  case Intrinsic::x86_mmx_psll_w:
2961  case Intrinsic::x86_mmx_psll_d:
2962  case Intrinsic::x86_mmx_psll_q:
2963  case Intrinsic::x86_mmx_pslli_w:
2964  case Intrinsic::x86_mmx_pslli_d:
2965  case Intrinsic::x86_mmx_pslli_q:
2966  case Intrinsic::x86_mmx_psrl_w:
2967  case Intrinsic::x86_mmx_psrl_d:
2968  case Intrinsic::x86_mmx_psrl_q:
2969  case Intrinsic::x86_mmx_psra_w:
2970  case Intrinsic::x86_mmx_psra_d:
2971  case Intrinsic::x86_mmx_psrli_w:
2972  case Intrinsic::x86_mmx_psrli_d:
2973  case Intrinsic::x86_mmx_psrli_q:
2974  case Intrinsic::x86_mmx_psrai_w:
2975  case Intrinsic::x86_mmx_psrai_d:
2976  handleVectorShiftIntrinsic(I, /* Variable */ false);
2977  break;
2978  case Intrinsic::x86_avx2_psllv_d:
2979  case Intrinsic::x86_avx2_psllv_d_256:
2980  case Intrinsic::x86_avx512_psllv_d_512:
2981  case Intrinsic::x86_avx2_psllv_q:
2982  case Intrinsic::x86_avx2_psllv_q_256:
2983  case Intrinsic::x86_avx512_psllv_q_512:
2984  case Intrinsic::x86_avx2_psrlv_d:
2985  case Intrinsic::x86_avx2_psrlv_d_256:
2986  case Intrinsic::x86_avx512_psrlv_d_512:
2987  case Intrinsic::x86_avx2_psrlv_q:
2988  case Intrinsic::x86_avx2_psrlv_q_256:
2989  case Intrinsic::x86_avx512_psrlv_q_512:
2990  case Intrinsic::x86_avx2_psrav_d:
2991  case Intrinsic::x86_avx2_psrav_d_256:
2992  case Intrinsic::x86_avx512_psrav_d_512:
2993  case Intrinsic::x86_avx512_psrav_q_128:
2994  case Intrinsic::x86_avx512_psrav_q_256:
2995  case Intrinsic::x86_avx512_psrav_q_512:
2996  handleVectorShiftIntrinsic(I, /* Variable */ true);
2997  break;
2998 
2999  case Intrinsic::x86_sse2_packsswb_128:
3000  case Intrinsic::x86_sse2_packssdw_128:
3001  case Intrinsic::x86_sse2_packuswb_128:
3002  case Intrinsic::x86_sse41_packusdw:
3003  case Intrinsic::x86_avx2_packsswb:
3004  case Intrinsic::x86_avx2_packssdw:
3005  case Intrinsic::x86_avx2_packuswb:
3006  case Intrinsic::x86_avx2_packusdw:
3007  handleVectorPackIntrinsic(I);
3008  break;
3009 
3010  case Intrinsic::x86_mmx_packsswb:
3011  case Intrinsic::x86_mmx_packuswb:
3012  handleVectorPackIntrinsic(I, 16);
3013  break;
3014 
3015  case Intrinsic::x86_mmx_packssdw:
3016  handleVectorPackIntrinsic(I, 32);
3017  break;
3018 
3019  case Intrinsic::x86_mmx_psad_bw:
3020  case Intrinsic::x86_sse2_psad_bw:
3021  case Intrinsic::x86_avx2_psad_bw:
3022  handleVectorSadIntrinsic(I);
3023  break;
3024 
3025  case Intrinsic::x86_sse2_pmadd_wd:
3026  case Intrinsic::x86_avx2_pmadd_wd:
3027  case Intrinsic::x86_ssse3_pmadd_ub_sw_128:
3028  case Intrinsic::x86_avx2_pmadd_ub_sw:
3029  handleVectorPmaddIntrinsic(I);
3030  break;
3031 
3032  case Intrinsic::x86_ssse3_pmadd_ub_sw:
3033  handleVectorPmaddIntrinsic(I, 8);
3034  break;
3035 
3036  case Intrinsic::x86_mmx_pmadd_wd:
3037  handleVectorPmaddIntrinsic(I, 16);
3038  break;
3039 
3040  case Intrinsic::x86_sse_cmp_ss:
3041  case Intrinsic::x86_sse2_cmp_sd:
3042  case Intrinsic::x86_sse_comieq_ss:
3043  case Intrinsic::x86_sse_comilt_ss:
3044  case Intrinsic::x86_sse_comile_ss:
3045  case Intrinsic::x86_sse_comigt_ss:
3046  case Intrinsic::x86_sse_comige_ss:
3047  case Intrinsic::x86_sse_comineq_ss:
3048  case Intrinsic::x86_sse_ucomieq_ss:
3049  case Intrinsic::x86_sse_ucomilt_ss:
3050  case Intrinsic::x86_sse_ucomile_ss:
3051  case Intrinsic::x86_sse_ucomigt_ss:
3052  case Intrinsic::x86_sse_ucomige_ss:
3053  case Intrinsic::x86_sse_ucomineq_ss:
3054  case Intrinsic::x86_sse2_comieq_sd:
3055  case Intrinsic::x86_sse2_comilt_sd:
3056  case Intrinsic::x86_sse2_comile_sd:
3057  case Intrinsic::x86_sse2_comigt_sd:
3058  case Intrinsic::x86_sse2_comige_sd:
3059  case Intrinsic::x86_sse2_comineq_sd:
3060  case Intrinsic::x86_sse2_ucomieq_sd:
3061  case Intrinsic::x86_sse2_ucomilt_sd:
3062  case Intrinsic::x86_sse2_ucomile_sd:
3063  case Intrinsic::x86_sse2_ucomigt_sd:
3064  case Intrinsic::x86_sse2_ucomige_sd:
3065  case Intrinsic::x86_sse2_ucomineq_sd:
3066  handleVectorCompareScalarIntrinsic(I);
3067  break;
3068 
3069  case Intrinsic::x86_sse_cmp_ps:
3070  case Intrinsic::x86_sse2_cmp_pd:
3071  // FIXME: For x86_avx_cmp_pd_256 and x86_avx_cmp_ps_256 this function
3072  // generates reasonably looking IR that fails in the backend with "Do not
3073  // know how to split the result of this operator!".
3074  handleVectorComparePackedIntrinsic(I);
3075  break;
3076 
3077  default:
3078  if (!handleUnknownIntrinsic(I))
3079  visitInstruction(I);
3080  break;
3081  }
3082  }
3083 
3084  void visitCallSite(CallSite CS) {
3085  Instruction &I = *CS.getInstruction();
3086  assert(!I.getMetadata("nosanitize"));
3087  assert((CS.isCall() || CS.isInvoke()) && "Unknown type of CallSite");
3088  if (CS.isCall()) {
3089  CallInst *Call = cast<CallInst>(&I);
3090 
3091  // For inline asm, do the usual thing: check argument shadow and mark all
3092  // outputs as clean. Note that any side effects of the inline asm that are
3093  // not immediately visible in its constraints are not handled.
3094  if (Call->isInlineAsm()) {
3096  visitAsmInstruction(I);
3097  else
3098  visitInstruction(I);
3099  return;
3100  }
3101 
3102  assert(!isa<IntrinsicInst>(&I) && "intrinsics are handled elsewhere");
3103 
3104  // We are going to insert code that relies on the fact that the callee
3105  // will become a non-readonly function after it is instrumented by us. To
3106  // prevent this code from being optimized out, mark that function
3107  // non-readonly in advance.
3108  if (Function *Func = Call->getCalledFunction()) {
3109  // Clear out readonly/readnone attributes.
3110  AttrBuilder B;
3111  B.addAttribute(Attribute::ReadOnly)
3112  .addAttribute(Attribute::ReadNone);
3114  }
3115 
3117  }
3118  IRBuilder<> IRB(&I);
3119 
3120  unsigned ArgOffset = 0;
3121  LLVM_DEBUG(dbgs() << " CallSite: " << I << "\n");
3122  for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
3123  ArgIt != End; ++ArgIt) {
3124  Value *A = *ArgIt;
3125  unsigned i = ArgIt - CS.arg_begin();
3126  if (!A->getType()->isSized()) {
3127  LLVM_DEBUG(dbgs() << "Arg " << i << " is not sized: " << I << "\n");
3128  continue;
3129  }
3130  unsigned Size = 0;
3131  Value *Store = nullptr;
3132  // Compute the Shadow for arg even if it is ByVal, because
3133  // in that case getShadow() will copy the actual arg shadow to
3134  // __msan_param_tls.
3135  Value *ArgShadow = getShadow(A);
3136  Value *ArgShadowBase = getShadowPtrForArgument(A, IRB, ArgOffset);
3137  LLVM_DEBUG(dbgs() << " Arg#" << i << ": " << *A
3138  << " Shadow: " << *ArgShadow << "\n");
3139  bool ArgIsInitialized = false;
3140  const DataLayout &DL = F.getParent()->getDataLayout();
3141  if (CS.paramHasAttr(i, Attribute::ByVal)) {
3142  assert(A->getType()->isPointerTy() &&
3143  "ByVal argument is not a pointer!");
3144  Size = DL.getTypeAllocSize(A->getType()->getPointerElementType());
3145  if (ArgOffset + Size > kParamTLSSize) break;
3146  unsigned ParamAlignment = CS.getParamAlignment(i);
3147  unsigned Alignment = std::min(ParamAlignment, kShadowTLSAlignment);
3148  Value *AShadowPtr =
3149  getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), Alignment,
3150  /*isStore*/ false)
3151  .first;
3152 
3153  Store = IRB.CreateMemCpy(ArgShadowBase, Alignment, AShadowPtr,
3154  Alignment, Size);
3155  // TODO(glider): need to copy origins.
3156  } else {
3157  Size = DL.getTypeAllocSize(A->getType());
3158  if (ArgOffset + Size > kParamTLSSize) break;
3159  Store = IRB.CreateAlignedStore(ArgShadow, ArgShadowBase,
3160  kShadowTLSAlignment);
3161  Constant *Cst = dyn_cast<Constant>(ArgShadow);
3162  if (Cst && Cst->isNullValue()) ArgIsInitialized = true;
3163  }
3164  if (MS.TrackOrigins && !ArgIsInitialized)
3165  IRB.CreateStore(getOrigin(A),
3166  getOriginPtrForArgument(A, IRB, ArgOffset));
3167  (void)Store;
3168  assert(Size != 0 && Store != nullptr);
3169  LLVM_DEBUG(dbgs() << " Param:" << *Store << "\n");
3170  ArgOffset += alignTo(Size, 8);
3171  }
3172  LLVM_DEBUG(dbgs() << " done with call args\n");
3173 
3174  FunctionType *FT =
3175  cast<FunctionType>(CS.getCalledValue()->getType()->getContainedType(0));
3176  if (FT->isVarArg()) {
3177  VAHelper->visitCallSite(CS, IRB);
3178  }
3179 
3180  // Now, get the shadow for the RetVal.
3181  if (!I.getType()->isSized()) return;
3182  // Don't emit the epilogue for musttail call returns.
3183  if (CS.isCall() && cast<CallInst>(&I)->isMustTailCall()) return;
3184  IRBuilder<> IRBBefore(&I);
3185  // Until we have full dynamic coverage, make sure the retval shadow is 0.
3186  Value *Base = getShadowPtrForRetval(&I, IRBBefore);
3187  IRBBefore.CreateAlignedStore(getCleanShadow(&I), Base, kShadowTLSAlignment);
3188  BasicBlock::iterator NextInsn;
3189  if (CS.isCall()) {
3190  NextInsn = ++I.getIterator();
3191  assert(NextInsn != I.getParent()->end());
3192  } else {
3193  BasicBlock *NormalDest = cast<InvokeInst>(&I)->getNormalDest();
3194  if (!NormalDest->getSinglePredecessor()) {
3195  // FIXME: this case is tricky, so we are just conservative here.
3196  // Perhaps we need to split the edge between this BB and NormalDest,
3197  // but a naive attempt to use SplitEdge leads to a crash.
3198  setShadow(&I, getCleanShadow(&I));
3199  setOrigin(&I, getCleanOrigin());
3200  return;
3201  }
3202  // FIXME: NextInsn is likely in a basic block that has not been visited yet.
3203  // Anything inserted there will be instrumented by MSan later!
3204  NextInsn = NormalDest->getFirstInsertionPt();
3205  assert(NextInsn != NormalDest->end() &&
3206  "Could not find insertion point for retval shadow load");
3207  }
3208  IRBuilder<> IRBAfter(&*NextInsn);
3209  Value *RetvalShadow =
3210  IRBAfter.CreateAlignedLoad(getShadowPtrForRetval(&I, IRBAfter),
3211  kShadowTLSAlignment, "_msret");
3212  setShadow(&I, RetvalShadow);
3213  if (MS.TrackOrigins)
3214  setOrigin(&I, IRBAfter.CreateLoad(getOriginPtrForRetval(IRBAfter)));
3215  }
3216 
3217  bool isAMustTailRetVal(Value *RetVal) {
3218  if (auto *I = dyn_cast<BitCastInst>(RetVal)) {
3219  RetVal = I->getOperand(0);
3220  }
3221  if (auto *I = dyn_cast<CallInst>(RetVal)) {
3222  return I->isMustTailCall();
3223  }
3224  return false;
3225  }
3226 
3227  void visitReturnInst(ReturnInst &I) {
3228  IRBuilder<> IRB(&I);
3229  Value *RetVal = I.getReturnValue();
3230  if (!RetVal) return;
3231  // Don't emit the epilogue for musttail call returns.
3232  if (isAMustTailRetVal(RetVal)) return;
3233  Value *ShadowPtr = getShadowPtrForRetval(RetVal, IRB);
3234  if (CheckReturnValue) {
3235  insertShadowCheck(RetVal, &I);
3236  Value *Shadow = getCleanShadow(RetVal);
3237  IRB.CreateAlignedStore(Shadow, ShadowPtr, kShadowTLSAlignment);
3238  } else {
3239  Value *Shadow = getShadow(RetVal);
3240  IRB.CreateAlignedStore(Shadow, ShadowPtr, kShadowTLSAlignment);
3241  if (MS.TrackOrigins)
3242  IRB.CreateStore(getOrigin(RetVal), getOriginPtrForRetval(IRB));
3243  }
3244  }
3245 
3246  void visitPHINode(PHINode &I) {
3247  IRBuilder<> IRB(&I);
3248  if (!PropagateShadow) {
3249  setShadow(&I, getCleanShadow(&I));
3250  setOrigin(&I, getCleanOrigin());
3251  return;
3252  }
3253 
3254  ShadowPHINodes.push_back(&I);
3255  setShadow(&I, IRB.CreatePHI(getShadowTy(&I), I.getNumIncomingValues(),
3256  "_msphi_s"));
3257  if (MS.TrackOrigins)
3258  setOrigin(&I, IRB.CreatePHI(MS.OriginTy, I.getNumIncomingValues(),
3259  "_msphi_o"));
3260  }
3261 
3262  Value *getLocalVarDescription(AllocaInst &I) {
3263  SmallString<2048> StackDescriptionStorage;
3264  raw_svector_ostream StackDescription(StackDescriptionStorage);
3265  // We create a string with a description of the stack allocation and
3266  // pass it into __msan_set_alloca_origin.
3267  // It will be printed by the run-time if stack-originated UMR is found.
3268  // The first 4 bytes of the string are set to '----' and will be replaced
3269  // by __msan_va_arg_overflow_size_tls at the first call.
3270  StackDescription << "----" << I.getName() << "@" << F.getName();
3272  StackDescription.str());
3273  }
3274 
3275  void instrumentAllocaUserspace(AllocaInst &I, IRBuilder<> &IRB, Value *Len) {
3276  if (PoisonStack && ClPoisonStackWithCall) {
3277  IRB.CreateCall(MS.MsanPoisonStackFn,
3278  {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len});
3279  } else {
3280  Value *ShadowBase, *OriginBase;
3281  std::tie(ShadowBase, OriginBase) =
3282  getShadowOriginPtr(&I, IRB, IRB.getInt8Ty(), 1, /*isStore*/ true);
3283 
3284  Value *PoisonValue = IRB.getInt8(PoisonStack ? ClPoisonStackPattern : 0);
3285  IRB.CreateMemSet(ShadowBase, PoisonValue, Len, I.getAlignment());
3286  }
3287 
3288  if (PoisonStack && MS.TrackOrigins) {
3289  Value *Descr = getLocalVarDescription(I);
3290  IRB.CreateCall(MS.MsanSetAllocaOrigin4Fn,
3291  {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len,
3292  IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy()),
3293  IRB.CreatePointerCast(&F, MS.IntptrTy)});
3294  }
3295  }
3296 
3297  void instrumentAllocaKmsan(AllocaInst &I, IRBuilder<> &IRB, Value *Len) {
3298  Value *Descr = getLocalVarDescription(I);
3299  if (PoisonStack) {
3300  IRB.CreateCall(MS.MsanPoisonAllocaFn,
3301  {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len,
3302  IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy())});
3303  } else {
3304  IRB.CreateCall(MS.MsanUnpoisonAllocaFn,
3305  {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len});
3306  }
3307  }
3308 
3309  void visitAllocaInst(AllocaInst &I) {
3310  setShadow(&I, getCleanShadow(&I));
3311  setOrigin(&I, getCleanOrigin());
3312  IRBuilder<> IRB(I.getNextNode());
3313  const DataLayout &DL = F.getParent()->getDataLayout();
3314  uint64_t TypeSize = DL.getTypeAllocSize(I.getAllocatedType());
3315  Value *Len = ConstantInt::get(MS.IntptrTy, TypeSize);
3316  if (I.isArrayAllocation())
3317  Len = IRB.CreateMul(Len, I.getArraySize());
3318 
3319  if (MS.CompileKernel)
3320  instrumentAllocaKmsan(I, IRB, Len);
3321  else
3322  instrumentAllocaUserspace(I, IRB, Len);
3323  }
3324 
3325  void visitSelectInst(SelectInst& I) {
3326  IRBuilder<> IRB(&I);
3327  // a = select b, c, d
3328  Value *B = I.getCondition();
3329  Value *C = I.getTrueValue();
3330  Value *D = I.getFalseValue();
3331  Value *Sb = getShadow(B);
3332  Value *Sc = getShadow(C);
3333  Value *Sd = getShadow(D);
3334 
3335  // Result shadow if condition shadow is 0.
3336  Value *Sa0 = IRB.CreateSelect(B, Sc, Sd);
3337  Value *Sa1;
3338  if (I.getType()->isAggregateType()) {
3339  // To avoid "sign extending" i1 to an arbitrary aggregate type, we just do
3340  // an extra "select". This results in much more compact IR.
3341  // Sa = select Sb, poisoned, (select b, Sc, Sd)
3342  Sa1 = getPoisonedShadow(getShadowTy(I.getType()));
3343  } else {
3344  // Sa = select Sb, [ (c^d) | Sc | Sd ], [ b ? Sc : Sd ]
3345  // If Sb (condition is poisoned), look for bits in c and d that are equal
3346  // and both unpoisoned.
3347  // If !Sb (condition is unpoisoned), simply pick one of Sc and Sd.
3348 
3349  // Cast arguments to shadow-compatible type.
3350  C = CreateAppToShadowCast(IRB, C);
3351  D = CreateAppToShadowCast(IRB, D);
3352 
3353  // Result shadow if condition shadow is 1.
3354  Sa1 = IRB.CreateOr(IRB.CreateXor(C, D), IRB.CreateOr(Sc, Sd));
3355  }
3356  Value *Sa = IRB.CreateSelect(Sb, Sa1, Sa0, "_msprop_select");
3357  setShadow(&I, Sa);
3358  if (MS.TrackOrigins) {
3359  // Origins are always i32, so any vector conditions must be flattened.
3360  // FIXME: consider tracking vector origins for app vectors?
3361  if (B->getType()->isVectorTy()) {
3362  Type *FlatTy = getShadowTyNoVec(B->getType());
3363  B = IRB.CreateICmpNE(IRB.CreateBitCast(B, FlatTy),
3364  ConstantInt::getNullValue(FlatTy));
3365  Sb = IRB.CreateICmpNE(IRB.CreateBitCast(Sb, FlatTy),
3366  ConstantInt::getNullValue(FlatTy));
3367  }
3368  // a = select b, c, d
3369  // Oa = Sb ? Ob : (b ? Oc : Od)
3370  setOrigin(
3371  &I, IRB.CreateSelect(Sb, getOrigin(I.getCondition()),
3372  IRB.CreateSelect(B, getOrigin(I.getTrueValue()),
3373  getOrigin(I.getFalseValue()))));
3374  }
3375  }
3376 
3377  void visitLandingPadInst(LandingPadInst &I) {
3378  // Do nothing.
3379  // See https://github.com/google/sanitizers/issues/504
3380  setShadow(&I, getCleanShadow(&I));
3381  setOrigin(&I, getCleanOrigin());
3382  }
3383 
3384  void visitCatchSwitchInst(CatchSwitchInst &I) {
3385  setShadow(&I, getCleanShadow(&I));
3386  setOrigin(&I, getCleanOrigin());
3387  }
3388 
3389  void visitFuncletPadInst(FuncletPadInst &I) {
3390  setShadow(&I, getCleanShadow(&I));
3391  setOrigin(&I, getCleanOrigin());
3392  }
3393 
3394  void visitGetElementPtrInst(GetElementPtrInst &I) {
3395  handleShadowOr(I);
3396  }
3397 
3398  void visitExtractValueInst(ExtractValueInst &I) {
3399  IRBuilder<> IRB(&I);
3400  Value *Agg = I.getAggregateOperand();
3401  LLVM_DEBUG(dbgs() << "ExtractValue: " << I << "\n");
3402  Value *AggShadow = getShadow(Agg);
3403  LLVM_DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n");
3404  Value *ResShadow = IRB.CreateExtractValue(AggShadow, I.getIndices());
3405  LLVM_DEBUG(dbgs() << " ResShadow: " << *ResShadow << "\n");
3406  setShadow(&I, ResShadow);
3407  setOriginForNaryOp(I);
3408  }
3409 
3410  void visitInsertValueInst(InsertValueInst &I) {
3411  IRBuilder<> IRB(&I);
3412  LLVM_DEBUG(dbgs() << "InsertValue: " << I << "\n");
3413  Value *AggShadow = getShadow(I.getAggregateOperand());
3414  Value *InsShadow = getShadow(I.getInsertedValueOperand());
3415  LLVM_DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n");
3416  LLVM_DEBUG(dbgs() << " InsShadow: " << *InsShadow << "\n");
3417  Value *Res = IRB.CreateInsertValue(AggShadow, InsShadow, I.getIndices());
3418  LLVM_DEBUG(dbgs() << " Res: " << *Res << "\n");
3419  setShadow(&I, Res);
3420  setOriginForNaryOp(I);
3421  }
3422 
3423  void dumpInst(Instruction &I) {
3424  if (CallInst *CI = dyn_cast<CallInst>(&I)) {
3425  errs() << "ZZZ call " << CI->getCalledFunction()->getName() << "\n";
3426  } else {
3427  errs() << "ZZZ " << I.getOpcodeName() << "\n";
3428  }
3429  errs() << "QQQ " << I << "\n";
3430  }
3431 
3432  void visitResumeInst(ResumeInst &I) {
3433  LLVM_DEBUG(dbgs() << "Resume: " << I << "\n");
3434  // Nothing to do here.
3435  }
3436 
3437  void visitCleanupReturnInst(CleanupReturnInst &CRI) {
3438  LLVM_DEBUG(dbgs() << "CleanupReturn: " << CRI << "\n");
3439  // Nothing to do here.
3440  }
3441 
3442  void visitCatchReturnInst(CatchReturnInst &CRI) {
3443  LLVM_DEBUG(dbgs() << "CatchReturn: " << CRI << "\n");
3444  // Nothing to do here.
3445  }
3446 
3447  void visitAsmInstruction(Instruction &I) {
3448  // Conservative inline assembly handling: check for poisoned shadow of
3449  // asm() arguments, then unpoison the result and all the memory locations
3450  // pointed to by those arguments.
3451  CallInst *CI = dyn_cast<CallInst>(&I);
3452 
3453  for (size_t i = 0, n = CI->getNumOperands(); i < n; i++) {
3454  Value *Operand = CI->getOperand(i);
3455  if (Operand->getType()->isSized())
3456  insertShadowCheck(Operand, &I);
3457  }
3458  setShadow(&I, getCleanShadow(&I));
3459  setOrigin(&I, getCleanOrigin());
3460  IRBuilder<> IRB(&I);
3461  IRB.SetInsertPoint(I.getNextNode());
3462  for (size_t i = 0, n = CI->getNumOperands(); i < n; i++) {
3463  Value *Operand = CI->getOperand(i);
3464  Type *OpType = Operand->getType();
3465  if (!OpType->isPointerTy())
3466  continue;
3467  Type *ElType = OpType->getPointerElementType();
3468  if (!ElType->isSized())
3469  continue;
3470  Value *ShadowPtr, *OriginPtr;
3471  std::tie(ShadowPtr, OriginPtr) = getShadowOriginPtr(
3472  Operand, IRB, ElType, /*Alignment*/ 1, /*isStore*/ true);
3473  Value *CShadow = getCleanShadow(ElType);
3474  IRB.CreateStore(
3475  CShadow,
3476  IRB.CreatePointerCast(ShadowPtr, CShadow->getType()->getPointerTo()));
3477  }
3478  }
3479 
3480  void visitInstruction(Instruction &I) {
3481  // Everything else: stop propagating and check for poisoned shadow.
3483  dumpInst(I);
3484  LLVM_DEBUG(dbgs() << "DEFAULT: " << I << "\n");
3485  for (size_t i = 0, n = I.getNumOperands(); i < n; i++) {
3486  Value *Operand = I.getOperand(i);
3487  if (Operand->getType()->isSized())
3488  insertShadowCheck(Operand, &I);
3489  }
3490  setShadow(&I, getCleanShadow(&I));
3491  setOrigin(&I, getCleanOrigin());
3492  }
3493 };
3494 
3495 /// AMD64-specific implementation of VarArgHelper.
3496 struct VarArgAMD64Helper : public VarArgHelper {
3497  // An unfortunate workaround for asymmetric lowering of va_arg stuff.
3498  // See a comment in visitCallSite for more details.
3499  static const unsigned AMD64GpEndOffset = 48; // AMD64 ABI Draft 0.99.6 p3.5.7
3500  static const unsigned AMD64FpEndOffsetSSE = 176;
3501  // If SSE is disabled, fp_offset in va_list is zero.
3502  static const unsigned AMD64FpEndOffsetNoSSE = AMD64GpEndOffset;
3503 
3504  unsigned AMD64FpEndOffset;
3505  Function &F;
3506  MemorySanitizer &MS;
3507  MemorySanitizerVisitor &MSV;
3508  Value *VAArgTLSCopy = nullptr;
3509  Value *VAArgTLSOriginCopy = nullptr;
3510  Value *VAArgOverflowSize = nullptr;
3511 
3512  SmallVector<CallInst*, 16> VAStartInstrumentationList;
3513 
3514  enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory };
3515 
3516  VarArgAMD64Helper(Function &F, MemorySanitizer &MS,
3517  MemorySanitizerVisitor &MSV)
3518  : F(F), MS(MS), MSV(MSV) {
3519  AMD64FpEndOffset = AMD64FpEndOffsetSSE;
3520  for (const auto &Attr : F.getAttributes().getFnAttributes()) {
3521  if (Attr.isStringAttribute() &&
3522  (Attr.getKindAsString() == "target-features")) {
3523  if (Attr.getValueAsString().contains("-sse"))
3524  AMD64FpEndOffset = AMD64FpEndOffsetNoSSE;
3525  break;
3526  }
3527  }
3528  }
3529 
3530  ArgKind classifyArgument(Value* arg) {
3531  // A very rough approximation of X86_64 argument classification rules.
3532  Type *T = arg->getType();
3533  if (T->isFPOrFPVectorTy() || T->isX86_MMXTy())
3534  return AK_FloatingPoint;
3535  if (T->isIntegerTy() && T->getPrimitiveSizeInBits() <= 64)
3536  return AK_GeneralPurpose;
3537  if (T->isPointerTy())
3538  return AK_GeneralPurpose;
3539  return AK_Memory;
3540  }
3541 
3542  // For VarArg functions, store the argument shadow in an ABI-specific format
3543  // that corresponds to va_list layout.
3544  // We do this because Clang lowers va_arg in the frontend, and this pass
3545  // only sees the low level code that deals with va_list internals.
3546  // A much easier alternative (provided that Clang emits va_arg instructions)
3547  // would have been to associate each live instance of va_list with a copy of
3548  // MSanParamTLS, and extract shadow on va_arg() call in the argument list
3549  // order.
3550  void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
3551  unsigned GpOffset = 0;
3552  unsigned FpOffset = AMD64GpEndOffset;
3553  unsigned OverflowOffset = AMD64FpEndOffset;
3554  const DataLayout &DL = F.getParent()->getDataLayout();
3555  for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
3556  ArgIt != End; ++ArgIt) {
3557  Value *A = *ArgIt;
3558  unsigned ArgNo = CS.getArgumentNo(ArgIt);
3559  bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams();
3560  bool IsByVal = CS.paramHasAttr(ArgNo, Attribute::ByVal);
3561  if (IsByVal) {
3562  // ByVal arguments always go to the overflow area.
3563  // Fixed arguments passed through the overflow area will be stepped
3564  // over by va_start, so don't count them towards the offset.
3565  if (IsFixed)
3566  continue;
3567  assert(A->getType()->isPointerTy());
3568  Type *RealTy = A->getType()->getPointerElementType();
3569  uint64_t ArgSize = DL.getTypeAllocSize(RealTy);
3570  Value *ShadowBase = getShadowPtrForVAArgument(
3571  RealTy, IRB, OverflowOffset, alignTo(ArgSize, 8));
3572  Value *OriginBase = nullptr;
3573  if (MS.TrackOrigins)
3574  OriginBase = getOriginPtrForVAArgument(RealTy, IRB, OverflowOffset);
3575  OverflowOffset += alignTo(ArgSize, 8);
3576  if (!ShadowBase)
3577  continue;
3578  Value *ShadowPtr, *OriginPtr;
3579  std::tie(ShadowPtr, OriginPtr) =
3580  MSV.getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), kShadowTLSAlignment,
3581  /*isStore*/ false);
3582 
3583  IRB.CreateMemCpy(ShadowBase, kShadowTLSAlignment, ShadowPtr,
3584  kShadowTLSAlignment, ArgSize);
3585  if (MS.TrackOrigins)
3586  IRB.CreateMemCpy(OriginBase, kShadowTLSAlignment, OriginPtr,
3587  kShadowTLSAlignment, ArgSize);
3588  } else {
3589  ArgKind AK = classifyArgument(A);
3590  if (AK == AK_GeneralPurpose && GpOffset >= AMD64GpEndOffset)
3591  AK = AK_Memory;
3592  if (AK == AK_FloatingPoint && FpOffset >= AMD64FpEndOffset)
3593  AK = AK_Memory;
3594  Value *ShadowBase, *OriginBase = nullptr;
3595  switch (AK) {
3596  case AK_GeneralPurpose:
3597  ShadowBase =
3598  getShadowPtrForVAArgument(A->getType(), IRB, GpOffset, 8);
3599  if (MS.TrackOrigins)
3600  OriginBase =
3601  getOriginPtrForVAArgument(A->getType(), IRB, GpOffset);
3602  GpOffset += 8;
3603  break;
3604  case AK_FloatingPoint:
3605  ShadowBase =
3606  getShadowPtrForVAArgument(A->getType(), IRB, FpOffset, 16);
3607  if (MS.TrackOrigins)
3608  OriginBase =
3609  getOriginPtrForVAArgument(A->getType(), IRB, FpOffset);
3610  FpOffset += 16;
3611  break;
3612  case AK_Memory:
3613  if (IsFixed)
3614  continue;
3615  uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
3616  ShadowBase =
3617  getShadowPtrForVAArgument(A->getType(), IRB, OverflowOffset, 8);
3618  if (MS.TrackOrigins)
3619  OriginBase =
3620  getOriginPtrForVAArgument(A->getType(), IRB, OverflowOffset);
3621  OverflowOffset += alignTo(ArgSize, 8);
3622  }
3623  // Take fixed arguments into account for GpOffset and FpOffset,
3624  // but don't actually store shadows for them.
3625  // TODO(glider): don't call get*PtrForVAArgument() for them.
3626  if (IsFixed)
3627  continue;
3628  if (!ShadowBase)
3629  continue;
3630  Value *Shadow = MSV.getShadow(A);
3631  IRB.CreateAlignedStore(Shadow, ShadowBase, kShadowTLSAlignment);
3632  if (MS.TrackOrigins) {
3633  Value *Origin = MSV.getOrigin(A);
3634  unsigned StoreSize = DL.getTypeStoreSize(Shadow->getType());
3635  MSV.paintOrigin(IRB, Origin, OriginBase, StoreSize,
3636  std::max(kShadowTLSAlignment, kMinOriginAlignment));
3637  }
3638  }
3639  }
3640  Constant *OverflowSize =
3641  ConstantInt::get(IRB.getInt64Ty(), OverflowOffset - AMD64FpEndOffset);
3642  IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS);
3643  }
3644 
3645  /// Compute the shadow address for a given va_arg.
3646  Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
3647  unsigned ArgOffset, unsigned ArgSize) {
3648  // Make sure we don't overflow __msan_va_arg_tls.
3649  if (ArgOffset + ArgSize > kParamTLSSize)
3650  return nullptr;
3651  Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
3652  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
3653  return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
3654  "_msarg_va_s");
3655  }
3656 
3657  /// Compute the origin address for a given va_arg.
3658  Value *getOriginPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, int ArgOffset) {
3659  Value *Base = IRB.CreatePointerCast(MS.VAArgOriginTLS, MS.IntptrTy);
3660  // getOriginPtrForVAArgument() is always called after
3661  // getShadowPtrForVAArgument(), so __msan_va_arg_origin_tls can never
3662  // overflow.
3663  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
3664  return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0),
3665  "_msarg_va_o");
3666  }
3667 
3668  void unpoisonVAListTagForInst(IntrinsicInst &I) {
3669  IRBuilder<> IRB(&I);
3670  Value *VAListTag = I.getArgOperand(0);
3671  Value *ShadowPtr, *OriginPtr;
3672  unsigned Alignment = 8;
3673  std::tie(ShadowPtr, OriginPtr) =
3674  MSV.getShadowOriginPtr(VAListTag, IRB, IRB.getInt8Ty(), Alignment,
3675  /*isStore*/ true);
3676 
3677  // Unpoison the whole __va_list_tag.
3678  // FIXME: magic ABI constants.
3679  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3680  /* size */ 24, Alignment, false);
3681  // We shouldn't need to zero out the origins, as they're only checked for
3682  // nonzero shadow.
3683  }
3684 
3685  void visitVAStartInst(VAStartInst &I) override {
3687  return;
3688  VAStartInstrumentationList.push_back(&I);
3689  unpoisonVAListTagForInst(I);
3690  }
3691 
3692  void visitVACopyInst(VACopyInst &I) override {
3693  if (F.getCallingConv() == CallingConv::Win64) return;
3694  unpoisonVAListTagForInst(I);
3695  }
3696 
3697  void finalizeInstrumentation() override {
3698  assert(!VAArgOverflowSize && !VAArgTLSCopy &&
3699  "finalizeInstrumentation called twice");
3700  if (!VAStartInstrumentationList.empty()) {
3701  // If there is a va_start in this function, make a backup copy of
3702  // va_arg_tls somewhere in the function entry block.
3703  IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI());
3704  VAArgOverflowSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
3705  Value *CopySize =
3706  IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, AMD64FpEndOffset),
3707  VAArgOverflowSize);
3708  VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
3709  IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize);
3710  if (MS.TrackOrigins) {
3711  VAArgTLSOriginCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
3712  IRB.CreateMemCpy(VAArgTLSOriginCopy, 8, MS.VAArgOriginTLS, 8, CopySize);
3713  }
3714  }
3715 
3716  // Instrument va_start.
3717  // Copy va_list shadow from the backup copy of the TLS contents.
3718  for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
3719  CallInst *OrigInst = VAStartInstrumentationList[i];
3720  IRBuilder<> IRB(OrigInst->getNextNode());
3721  Value *VAListTag = OrigInst->getArgOperand(0);
3722 
3723  Value *RegSaveAreaPtrPtr = IRB.CreateIntToPtr(
3724  IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
3725  ConstantInt::get(MS.IntptrTy, 16)),
3727  Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
3728  Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
3729  unsigned Alignment = 16;
3730  std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) =
3731  MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(),
3732  Alignment, /*isStore*/ true);
3733  IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment,
3734  AMD64FpEndOffset);
3735  if (MS.TrackOrigins)
3736  IRB.CreateMemCpy(RegSaveAreaOriginPtr, Alignment, VAArgTLSOriginCopy,
3737  Alignment, AMD64FpEndOffset);
3738  Value *OverflowArgAreaPtrPtr = IRB.CreateIntToPtr(
3739  IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
3740  ConstantInt::get(MS.IntptrTy, 8)),
3742  Value *OverflowArgAreaPtr = IRB.CreateLoad(OverflowArgAreaPtrPtr);
3743  Value *OverflowArgAreaShadowPtr, *OverflowArgAreaOriginPtr;
3744  std::tie(OverflowArgAreaShadowPtr, OverflowArgAreaOriginPtr) =
3745  MSV.getShadowOriginPtr(OverflowArgAreaPtr, IRB, IRB.getInt8Ty(),
3746  Alignment, /*isStore*/ true);
3747  Value *SrcPtr = IRB.CreateConstGEP1_32(IRB.getInt8Ty(), VAArgTLSCopy,
3748  AMD64FpEndOffset);
3749  IRB.CreateMemCpy(OverflowArgAreaShadowPtr, Alignment, SrcPtr, Alignment,
3750  VAArgOverflowSize);
3751  if (MS.TrackOrigins) {
3752  SrcPtr = IRB.CreateConstGEP1_32(IRB.getInt8Ty(), VAArgTLSOriginCopy,
3753  AMD64FpEndOffset);
3754  IRB.CreateMemCpy(OverflowArgAreaOriginPtr, Alignment, SrcPtr, Alignment,
3755  VAArgOverflowSize);
3756  }
3757  }
3758  }
3759 };
3760 
3761 /// MIPS64-specific implementation of VarArgHelper.
3762 struct VarArgMIPS64Helper : public VarArgHelper {
3763  Function &F;
3764  MemorySanitizer &MS;
3765  MemorySanitizerVisitor &MSV;
3766  Value *VAArgTLSCopy = nullptr;
3767  Value *VAArgSize = nullptr;
3768 
3769  SmallVector<CallInst*, 16> VAStartInstrumentationList;
3770 
3771  VarArgMIPS64Helper(Function &F, MemorySanitizer &MS,
3772  MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {}
3773 
3774  void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
3775  unsigned VAArgOffset = 0;
3776  const DataLayout &DL = F.getParent()->getDataLayout();
3777  for (CallSite::arg_iterator ArgIt = CS.arg_begin() +
3778  CS.getFunctionType()->getNumParams(), End = CS.arg_end();
3779  ArgIt != End; ++ArgIt) {
3780  Triple TargetTriple(F.getParent()->getTargetTriple());
3781  Value *A = *ArgIt;
3782  Value *Base;
3783  uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
3784  if (TargetTriple.getArch() == Triple::mips64) {
3785  // Adjusting the shadow for argument with size < 8 to match the placement
3786  // of bits in big endian system
3787  if (ArgSize < 8)
3788  VAArgOffset += (8 - ArgSize);
3789  }
3790  Base = getShadowPtrForVAArgument(A->getType(), IRB, VAArgOffset, ArgSize);
3791  VAArgOffset += ArgSize;
3792  VAArgOffset = alignTo(VAArgOffset, 8);
3793  if (!Base)
3794  continue;
3795  IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment);
3796  }
3797 
3798  Constant *TotalVAArgSize = ConstantInt::get(IRB.getInt64Ty(), VAArgOffset);
3799  // Here using VAArgOverflowSizeTLS as VAArgSizeTLS to avoid creation of
3800  // a new class member i.e. it is the total size of all VarArgs.
3801  IRB.CreateStore(TotalVAArgSize, MS.VAArgOverflowSizeTLS);
3802  }
3803 
3804  /// Compute the shadow address for a given va_arg.
3805  Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
3806  unsigned ArgOffset, unsigned ArgSize) {
3807  // Make sure we don't overflow __msan_va_arg_tls.
3808  if (ArgOffset + ArgSize > kParamTLSSize)
3809  return nullptr;
3810  Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
3811  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
3812  return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
3813  "_msarg");
3814  }
3815 
3816  void visitVAStartInst(VAStartInst &I) override {
3817  IRBuilder<> IRB(&I);
3818  VAStartInstrumentationList.push_back(&I);
3819  Value *VAListTag = I.getArgOperand(0);
3820  Value *ShadowPtr, *OriginPtr;
3821  unsigned Alignment = 8;
3822  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
3823  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
3824  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3825  /* size */ 8, Alignment, false);
3826  }
3827 
3828  void visitVACopyInst(VACopyInst &I) override {
3829  IRBuilder<> IRB(&I);
3830  VAStartInstrumentationList.push_back(&I);
3831  Value *VAListTag = I.getArgOperand(0);
3832  Value *ShadowPtr, *OriginPtr;
3833  unsigned Alignment = 8;
3834  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
3835  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
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 /// AArch64-specific implementation of VarArgHelper.
3877 struct VarArgAArch64Helper : public VarArgHelper {
3878  static const unsigned kAArch64GrArgSize = 64;
3879  static const unsigned kAArch64VrArgSize = 128;
3880 
3881  static const unsigned AArch64GrBegOffset = 0;
3882  static const unsigned AArch64GrEndOffset = kAArch64GrArgSize;
3883  // Make VR space aligned to 16 bytes.
3884  static const unsigned AArch64VrBegOffset = AArch64GrEndOffset;
3885  static const unsigned AArch64VrEndOffset = AArch64VrBegOffset
3886  + kAArch64VrArgSize;
3887  static const unsigned AArch64VAEndOffset = AArch64VrEndOffset;
3888 
3889  Function &F;
3890  MemorySanitizer &MS;
3891  MemorySanitizerVisitor &MSV;
3892  Value *VAArgTLSCopy = nullptr;
3893  Value *VAArgOverflowSize = nullptr;
3894 
3895  SmallVector<CallInst*, 16> VAStartInstrumentationList;
3896 
3897  enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory };
3898 
3899  VarArgAArch64Helper(Function &F, MemorySanitizer &MS,
3900  MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {}
3901 
3902  ArgKind classifyArgument(Value* arg) {
3903  Type *T = arg->getType();
3904  if (T->isFPOrFPVectorTy())
3905  return AK_FloatingPoint;
3906  if ((T->isIntegerTy() && T->getPrimitiveSizeInBits() <= 64)
3907  || (T->isPointerTy()))
3908  return AK_GeneralPurpose;
3909  return AK_Memory;
3910  }
3911 
3912  // The instrumentation stores the argument shadow in a non ABI-specific
3913  // format because it does not know which argument is named (since Clang,
3914  // like x86_64 case, lowers the va_args in the frontend and this pass only
3915  // sees the low level code that deals with va_list internals).
3916  // The first seven GR registers are saved in the first 56 bytes of the
3917  // va_arg tls arra, followers by the first 8 FP/SIMD registers, and then
3918  // the remaining arguments.
3919  // Using constant offset within the va_arg TLS array allows fast copy
3920  // in the finalize instrumentation.
3921  void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
3922  unsigned GrOffset = AArch64GrBegOffset;
3923  unsigned VrOffset = AArch64VrBegOffset;
3924  unsigned OverflowOffset = AArch64VAEndOffset;
3925 
3926  const DataLayout &DL = F.getParent()->getDataLayout();
3927  for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
3928  ArgIt != End; ++ArgIt) {
3929  Value *A = *ArgIt;
3930  unsigned ArgNo = CS.getArgumentNo(ArgIt);
3931  bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams();
3932  ArgKind AK = classifyArgument(A);
3933  if (AK == AK_GeneralPurpose && GrOffset >= AArch64GrEndOffset)
3934  AK = AK_Memory;
3935  if (AK == AK_FloatingPoint && VrOffset >= AArch64VrEndOffset)
3936  AK = AK_Memory;
3937  Value *Base;
3938  switch (AK) {
3939  case AK_GeneralPurpose:
3940  Base = getShadowPtrForVAArgument(A->getType(), IRB, GrOffset, 8);
3941  GrOffset += 8;
3942  break;
3943  case AK_FloatingPoint:
3944  Base = getShadowPtrForVAArgument(A->getType(), IRB, VrOffset, 8);
3945  VrOffset += 16;
3946  break;
3947  case AK_Memory:
3948  // Don't count fixed arguments in the overflow area - va_start will
3949  // skip right over them.
3950  if (IsFixed)
3951  continue;
3952  uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
3953  Base = getShadowPtrForVAArgument(A->getType(), IRB, OverflowOffset,
3954  alignTo(ArgSize, 8));
3955  OverflowOffset += alignTo(ArgSize, 8);
3956  break;
3957  }
3958  // Count Gp/Vr fixed arguments to their respective offsets, but don't
3959  // bother to actually store a shadow.
3960  if (IsFixed)
3961  continue;
3962  if (!Base)
3963  continue;
3964  IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment);
3965  }
3966  Constant *OverflowSize =
3967  ConstantInt::get(IRB.getInt64Ty(), OverflowOffset - AArch64VAEndOffset);
3968  IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS);
3969  }
3970 
3971  /// Compute the shadow address for a given va_arg.
3972  Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
3973  unsigned ArgOffset, unsigned ArgSize) {
3974  // Make sure we don't overflow __msan_va_arg_tls.
3975  if (ArgOffset + ArgSize > kParamTLSSize)
3976  return nullptr;
3977  Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
3978  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
3979  return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
3980  "_msarg");
3981  }
3982 
3983  void visitVAStartInst(VAStartInst &I) override {
3984  IRBuilder<> IRB(&I);
3985  VAStartInstrumentationList.push_back(&I);
3986  Value *VAListTag = I.getArgOperand(0);
3987  Value *ShadowPtr, *OriginPtr;
3988  unsigned Alignment = 8;
3989  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
3990  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
3991  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3992  /* size */ 32, Alignment, false);
3993  }
3994 
3995  void visitVACopyInst(VACopyInst &I) override {
3996  IRBuilder<> IRB(&I);
3997  VAStartInstrumentationList.push_back(&I);
3998  Value *VAListTag = I.getArgOperand(0);
3999  Value *ShadowPtr, *OriginPtr;
4000  unsigned Alignment = 8;
4001  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
4002  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
4003  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
4004  /* size */ 32, Alignment, false);
4005  }
4006 
4007  // Retrieve a va_list field of 'void*' size.
4008  Value* getVAField64(IRBuilder<> &IRB, Value *VAListTag, int offset) {
4009  Value *SaveAreaPtrPtr =
4010  IRB.CreateIntToPtr(
4011  IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
4012  ConstantInt::get(MS.IntptrTy, offset)),
4013  Type::getInt64PtrTy(*MS.C));
4014  return IRB.CreateLoad(SaveAreaPtrPtr);
4015  }
4016 
4017  // Retrieve a va_list field of 'int' size.
4018  Value* getVAField32(IRBuilder<> &IRB, Value *VAListTag, int offset) {
4019  Value *SaveAreaPtr =
4020  IRB.CreateIntToPtr(
4021  IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
4022  ConstantInt::get(MS.IntptrTy, offset)),
4023  Type::getInt32PtrTy(*MS.C));
4024  Value *SaveArea32 = IRB.CreateLoad(SaveAreaPtr);
4025  return IRB.CreateSExt(SaveArea32, MS.IntptrTy);
4026  }
4027 
4028  void finalizeInstrumentation() override {
4029  assert(!VAArgOverflowSize && !VAArgTLSCopy &&
4030  "finalizeInstrumentation called twice");
4031  if (!VAStartInstrumentationList.empty()) {
4032  // If there is a va_start in this function, make a backup copy of
4033  // va_arg_tls somewhere in the function entry block.
4034  IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI());
4035  VAArgOverflowSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
4036  Value *CopySize =
4037  IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, AArch64VAEndOffset),
4038  VAArgOverflowSize);
4039  VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
4040  IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize);
4041  }
4042 
4043  Value *GrArgSize = ConstantInt::get(MS.IntptrTy, kAArch64GrArgSize);
4044  Value *VrArgSize = ConstantInt::get(MS.IntptrTy, kAArch64VrArgSize);
4045 
4046  // Instrument va_start, copy va_list shadow from the backup copy of
4047  // the TLS contents.
4048  for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
4049  CallInst *OrigInst = VAStartInstrumentationList[i];
4050  IRBuilder<> IRB(OrigInst->getNextNode());
4051 
4052  Value *VAListTag = OrigInst->getArgOperand(0);
4053 
4054  // The variadic ABI for AArch64 creates two areas to save the incoming
4055  // argument registers (one for 64-bit general register xn-x7 and another
4056  // for 128-bit FP/SIMD vn-v7).
4057  // We need then to propagate the shadow arguments on both regions
4058  // 'va::__gr_top + va::__gr_offs' and 'va::__vr_top + va::__vr_offs'.
4059  // The remaning arguments are saved on shadow for 'va::stack'.
4060  // One caveat is it requires only to propagate the non-named arguments,
4061  // however on the call site instrumentation 'all' the arguments are
4062  // saved. So to copy the shadow values from the va_arg TLS array
4063  // we need to adjust the offset for both GR and VR fields based on
4064  // the __{gr,vr}_offs value (since they are stores based on incoming
4065  // named arguments).
4066 
4067  // Read the stack pointer from the va_list.
4068  Value *StackSaveAreaPtr = getVAField64(IRB, VAListTag, 0);
4069 
4070  // Read both the __gr_top and __gr_off and add them up.
4071  Value *GrTopSaveAreaPtr = getVAField64(IRB, VAListTag, 8);
4072  Value *GrOffSaveArea = getVAField32(IRB, VAListTag, 24);
4073 
4074  Value *GrRegSaveAreaPtr = IRB.CreateAdd(GrTopSaveAreaPtr, GrOffSaveArea);
4075 
4076  // Read both the __vr_top and __vr_off and add them up.
4077  Value *VrTopSaveAreaPtr = getVAField64(IRB, VAListTag, 16);
4078  Value *VrOffSaveArea = getVAField32(IRB, VAListTag, 28);
4079 
4080  Value *VrRegSaveAreaPtr = IRB.CreateAdd(VrTopSaveAreaPtr, VrOffSaveArea);
4081 
4082  // It does not know how many named arguments is being used and, on the
4083  // callsite all the arguments were saved. Since __gr_off is defined as
4084  // '0 - ((8 - named_gr) * 8)', the idea is to just propagate the variadic
4085  // argument by ignoring the bytes of shadow from named arguments.
4086  Value *GrRegSaveAreaShadowPtrOff =
4087  IRB.CreateAdd(GrArgSize, GrOffSaveArea);
4088 
4089  Value *GrRegSaveAreaShadowPtr =
4090  MSV.getShadowOriginPtr(GrRegSaveAreaPtr, IRB, IRB.getInt8Ty(),
4091  /*Alignment*/ 8, /*isStore*/ true)
4092  .first;
4093 
4094  Value *GrSrcPtr = IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy,
4095  GrRegSaveAreaShadowPtrOff);
4096  Value *GrCopySize = IRB.CreateSub(GrArgSize, GrRegSaveAreaShadowPtrOff);
4097 
4098  IRB.CreateMemCpy(GrRegSaveAreaShadowPtr, 8, GrSrcPtr, 8, GrCopySize);
4099 
4100  // Again, but for FP/SIMD values.
4101  Value *VrRegSaveAreaShadowPtrOff =
4102  IRB.CreateAdd(VrArgSize, VrOffSaveArea);
4103 
4104  Value *VrRegSaveAreaShadowPtr =
4105  MSV.getShadowOriginPtr(VrRegSaveAreaPtr, IRB, IRB.getInt8Ty(),
4106  /*Alignment*/ 8, /*isStore*/ true)
4107  .first;
4108 
4109  Value *VrSrcPtr = IRB.CreateInBoundsGEP(
4110  IRB.getInt8Ty(),
4111  IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy,
4112  IRB.getInt32(AArch64VrBegOffset)),
4113  VrRegSaveAreaShadowPtrOff);
4114  Value *VrCopySize = IRB.CreateSub(VrArgSize, VrRegSaveAreaShadowPtrOff);
4115 
4116  IRB.CreateMemCpy(VrRegSaveAreaShadowPtr, 8, VrSrcPtr, 8, VrCopySize);
4117 
4118  // And finally for remaining arguments.
4119  Value *StackSaveAreaShadowPtr =
4120  MSV.getShadowOriginPtr(StackSaveAreaPtr, IRB, IRB.getInt8Ty(),
4121  /*Alignment*/ 16, /*isStore*/ true)
4122  .first;
4123 
4124  Value *StackSrcPtr =
4125  IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy,
4126  IRB.getInt32(AArch64VAEndOffset));
4127 
4128  IRB.CreateMemCpy(StackSaveAreaShadowPtr, 16, StackSrcPtr, 16,
4129  VAArgOverflowSize);
4130  }
4131  }
4132 };
4133 
4134 /// PowerPC64-specific implementation of VarArgHelper.
4135 struct VarArgPowerPC64Helper : public VarArgHelper {
4136  Function &F;
4137  MemorySanitizer &MS;
4138  MemorySanitizerVisitor &MSV;
4139  Value *VAArgTLSCopy = nullptr;
4140  Value *VAArgSize = nullptr;
4141 
4142  SmallVector<CallInst*, 16> VAStartInstrumentationList;
4143 
4144  VarArgPowerPC64Helper(Function &F, MemorySanitizer &MS,
4145  MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {}
4146 
4147  void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
4148  // For PowerPC, we need to deal with alignment of stack arguments -
4149  // they are mostly aligned to 8 bytes, but vectors and i128 arrays
4150  // are aligned to 16 bytes, byvals can be aligned to 8 or 16 bytes,
4151  // and QPX vectors are aligned to 32 bytes. For that reason, we
4152  // compute current offset from stack pointer (which is always properly
4153  // aligned), and offset for the first vararg, then subtract them.
4154  unsigned VAArgBase;
4155  Triple TargetTriple(F.getParent()->getTargetTriple());
4156  // Parameter save area starts at 48 bytes from frame pointer for ABIv1,
4157  // and 32 bytes for ABIv2. This is usually determined by target
4158  // endianness, but in theory could be overriden by function attribute.
4159  // For simplicity, we ignore it here (it'd only matter for QPX vectors).
4160  if (TargetTriple.getArch() == Triple::ppc64)
4161  VAArgBase = 48;
4162  else
4163  VAArgBase = 32;
4164  unsigned VAArgOffset = VAArgBase;
4165  const DataLayout &DL = F.getParent()->getDataLayout();
4166  for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
4167  ArgIt != End; ++ArgIt) {
4168  Value *A = *ArgIt;
4169  unsigned ArgNo = CS.getArgumentNo(ArgIt);
4170  bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams();
4171  bool IsByVal = CS.paramHasAttr(ArgNo, Attribute::ByVal);
4172  if (IsByVal) {
4173  assert(A->getType()->isPointerTy());
4174  Type *RealTy = A->getType()->getPointerElementType();
4175  uint64_t ArgSize = DL.getTypeAllocSize(RealTy);
4176  uint64_t ArgAlign = CS.getParamAlignment(ArgNo);
4177  if (ArgAlign < 8)
4178  ArgAlign = 8;
4179  VAArgOffset = alignTo(VAArgOffset, ArgAlign);
4180  if (!IsFixed) {
4181  Value *Base = getShadowPtrForVAArgument(
4182  RealTy, IRB, VAArgOffset - VAArgBase, ArgSize);
4183  if (Base) {
4184  Value *AShadowPtr, *AOriginPtr;
4185  std::tie(AShadowPtr, AOriginPtr) =
4186  MSV.getShadowOriginPtr(A, IRB, IRB.getInt8Ty(),
4187  kShadowTLSAlignment, /*isStore*/ false);
4188 
4189  IRB.CreateMemCpy(Base, kShadowTLSAlignment, AShadowPtr,
4190  kShadowTLSAlignment, ArgSize);
4191  }
4192  }
4193  VAArgOffset += alignTo(ArgSize, 8);
4194  } else {
4195  Value *Base;
4196  uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
4197  uint64_t ArgAlign = 8;
4198  if (A->getType()->isArrayTy()) {
4199  // Arrays are aligned to element size, except for long double
4200  // arrays, which are aligned to 8 bytes.
4201  Type *ElementTy = A->getType()->getArrayElementType();
4202  if (!ElementTy->isPPC_FP128Ty())
4203  ArgAlign = DL.getTypeAllocSize(ElementTy);
4204  } else if (A->getType()->isVectorTy()) {
4205  // Vectors are naturally aligned.
4206  ArgAlign = DL.getTypeAllocSize(A->getType());
4207  }
4208  if (ArgAlign < 8)
4209  ArgAlign = 8;
4210  VAArgOffset = alignTo(VAArgOffset, ArgAlign);
4211  if (DL.isBigEndian()) {
4212  // Adjusting the shadow for argument with size < 8 to match the placement
4213  // of bits in big endian system
4214  if (ArgSize < 8)
4215  VAArgOffset += (8 - ArgSize);
4216  }
4217  if (!IsFixed) {
4218  Base = getShadowPtrForVAArgument(A->getType(), IRB,
4219  VAArgOffset - VAArgBase, ArgSize);
4220  if (Base)
4221  IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment);
4222  }
4223  VAArgOffset += ArgSize;
4224  VAArgOffset = alignTo(VAArgOffset, 8);
4225  }
4226  if (IsFixed)
4227  VAArgBase = VAArgOffset;
4228  }
4229 
4230  Constant *TotalVAArgSize = ConstantInt::get(IRB.getInt64Ty(),
4231  VAArgOffset - VAArgBase);
4232  // Here using VAArgOverflowSizeTLS as VAArgSizeTLS to avoid creation of
4233  // a new class member i.e. it is the total size of all VarArgs.
4234  IRB.CreateStore(TotalVAArgSize, MS.VAArgOverflowSizeTLS);
4235  }
4236 
4237  /// Compute the shadow address for a given va_arg.
4238  Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
4239  unsigned ArgOffset, unsigned ArgSize) {
4240  // Make sure we don't overflow __msan_va_arg_tls.
4241  if (ArgOffset + ArgSize > kParamTLSSize)
4242  return nullptr;
4243  Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
4244  Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
4245  return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
4246  "_msarg");
4247  }
4248 
4249  void visitVAStartInst(VAStartInst &I) override {
4250  IRBuilder<> IRB(&I);
4251  VAStartInstrumentationList.push_back(&I);
4252  Value *VAListTag = I.getArgOperand(0);
4253  Value *ShadowPtr, *OriginPtr;
4254  unsigned Alignment = 8;
4255  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
4256  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
4257  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
4258  /* size */ 8, Alignment, false);
4259  }
4260 
4261  void visitVACopyInst(VACopyInst &I) override {
4262  IRBuilder<> IRB(&I);
4263  Value *VAListTag = I.getArgOperand(0);
4264  Value *ShadowPtr, *OriginPtr;
4265  unsigned Alignment = 8;
4266  std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
4267  VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
4268  // Unpoison the whole __va_list_tag.
4269  // FIXME: magic ABI constants.
4270  IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
4271  /* size */ 8, Alignment, false);
4272  }
4273 
4274  void finalizeInstrumentation() override {
4275  assert(!VAArgSize && !VAArgTLSCopy &&
4276  "finalizeInstrumentation called twice");
4277  IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI());
4278  VAArgSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
4279  Value *CopySize = IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, 0),
4280  VAArgSize);
4281 
4282  if (!VAStartInstrumentationList.empty()) {
4283  // If there is a va_start in this function, make a backup copy of
4284  // va_arg_tls somewhere in the function entry block.
4285  VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
4286  IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize);
4287  }
4288 
4289  // Instrument va_start.
4290  // Copy va_list shadow from the backup copy of the TLS contents.
4291  for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
4292  CallInst *OrigInst = VAStartInstrumentationList[i];
4293  IRBuilder<> IRB(OrigInst->getNextNode());
4294  Value *VAListTag = OrigInst->getArgOperand(0);
4295  Value *RegSaveAreaPtrPtr =
4296  IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
4298  Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
4299  Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
4300  unsigned Alignment = 8;
4301  std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) =
4302  MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(),
4303  Alignment, /*isStore*/ true);
4304  IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment,
4305  CopySize);
4306  }
4307  }
4308 };
4309 
4310 /// A no-op implementation of VarArgHelper.
4311 struct VarArgNoOpHelper : public VarArgHelper {
4312  VarArgNoOpHelper(Function &F, MemorySanitizer &MS,
4313  MemorySanitizerVisitor &MSV) {}
4314 
4315  void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {}
4316 
4317  void visitVAStartInst(VAStartInst &I) override {}
4318 
4319  void visitVACopyInst(VACopyInst &I) override {}
4320 
4321  void finalizeInstrumentation() override {}
4322 };
4323 
4324 } // end anonymous namespace
4325 
4326 static VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
4327  MemorySanitizerVisitor &Visitor) {
4328  // VarArg handling is only implemented on AMD64. False positives are possible
4329  // on other platforms.
4330  Triple TargetTriple(Func.getParent()->getTargetTriple());
4331  if (TargetTriple.getArch() == Triple::x86_64)
4332  return new VarArgAMD64Helper(Func, Msan, Visitor);
4333  else if (TargetTriple.isMIPS64())
4334  return new VarArgMIPS64Helper(Func, Msan, Visitor);
4335  else if (TargetTriple.getArch() == Triple::aarch64)
4336  return new VarArgAArch64Helper(Func, Msan, Visitor);
4337  else if (TargetTriple.getArch() == Triple::ppc64 ||
4338  TargetTriple.getArch() == Triple::ppc64le)
4339  return new VarArgPowerPC64Helper(Func, Msan, Visitor);
4340  else
4341  return new VarArgNoOpHelper(Func, Msan, Visitor);
4342 }
4343 
4345  if (!CompileKernel && (&F == MsanCtorFunction))
4346  return false;
4347  MemorySanitizerVisitor Visitor(F, *this);
4348 
4349  // Clear out readonly/readnone attributes.
4350  AttrBuilder B;
4351  B.addAttribute(Attribute::ReadOnly)
4352  .addAttribute(Attribute::ReadNone);
4354 
4355  return Visitor.runOnFunction();
4356 }
Value * CreateInBoundsGEP(Value *Ptr, ArrayRef< Value *> IdxList, const Twine &Name="")
Definition: IRBuilder.h:1393
Type * getVectorElementType() const
Definition: Type.h:371
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:68
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:552
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:111
constexpr char Align[]
Key for Kernel::Arg::Metadata::mAlign.
const std::string & getTargetTriple() const
Get the target triple which is a string describing the target host.
Definition: Module.h:239
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:1846
Value * CreateConstGEP1_32(Value *Ptr, unsigned Idx0, const Twine &Name="")
Definition: IRBuilder.h:1432
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:2515
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:1246
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:1292
Base class for instruction visitors.
Definition: InstVisitor.h:81
Value * getAggregateOperand()
Value * CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1740
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:139
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
BinaryOps getOpcode() const
Definition: InstrTypes.h:355
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:143
Value * CreateXor(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1148
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:64
bool isSized(SmallPtrSetImpl< Type *> *Visited=nullptr) const
Return true if it makes sense to take the size of this type.
Definition: Type.h:265
#define LLVM_FALLTHROUGH
Definition: Compiler.h:86
void setOrdering(AtomicOrdering Ordering)
Sets the ordering constraint of this rmw instruction.
Definition: Instructions.h:766
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:518
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
bool removeUnreachableBlocks(Function &F, LazyValueInfo *LVI=nullptr, DomTreeUpdater *DTU=nullptr, MemorySSAUpdater *MSSAU=nullptr)
Remove all blocks that can not be reached from the function&#39;s entry.
Definition: Local.cpp:2218
Value * CreateICmpSLT(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1768
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:243
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:237
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:321
A raw_ostream that writes to an SmallVector or SmallString.
Definition: raw_ostream.h:510
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:1560
Metadata node.
Definition: Metadata.h:864
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:685
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:168
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:681
Hexagon Common GEP
bool isVectorTy() const
True if this is an instance of VectorType.
Definition: Type.h:230
#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:960
unsigned getBitWidth() const
Return the number of bits in the APInt.
Definition: APInt.h:1503
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:268
Value * CreateNot(Value *V, const Twine &Name="")
Definition: IRBuilder.h:1282
StoreInst * CreateAlignedStore(Value *Val, Value *Ptr, unsigned Align, bool isVolatile=false)
Definition: IRBuilder.h:1346
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:1626
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
Definition: InstrTypes.h:854
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:376
const DataLayout & getDataLayout() const
Get the data layout for the module&#39;s target platform.
Definition: Module.cpp:364
unsigned getAlignment() const
Return the alignment of the memory that is being allocated by the instruction.
Definition: Instructions.h:113
IntegerType * getInt64Ty()
Fetch the type representing a 64-bit integer.
Definition: IRBuilder.h:352
This is the base class for all instructions that perform data casts.
Definition: InstrTypes.h:392
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:1275
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:243
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
Definition: InstrTypes.h:860
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:731
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:962
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:1321
Value * CreateIntToPtr(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1624
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:1629
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:239
AtomicOrdering getSuccessOrdering() const
Returns the success ordering constraint of this cmpxchg instruction.
Definition: Instructions.h:572
#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:217
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:979
AttributeList getAttributes() const
Return the attribute list for this Function.
Definition: Function.h:224
An instruction for storing to memory.
Definition: Instructions.h:310
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:1556
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:1021
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:1130
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:338
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:304
Value * getOperand(unsigned i_nocapture) const
bool isZeroValue() const
Return true if the value is negative zero or null value.
Definition: Constants.cpp:65
The C convention as implemented on Windows/x86-64 and AArch64.
Definition: CallingConv.h:154
bool isVoidTy() const
Return true if this is &#39;void&#39;.
Definition: Type.h:141
const BasicBlock & getEntryBlock() const
Definition: Function.h:640
an instruction for type-safe pointer arithmetic to access elements of arrays and structs ...
Definition: Instructions.h:841
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:1305
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:410
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:189
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:218
const BasicBlock * getSinglePredecessor() const
Return the predecessor of this block if it has a single predecessor block.
Definition: BasicBlock.cpp:235
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:1901
bool isPointerTy() const
True if this is an instance of PointerType.
Definition: Type.h:224
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
Value * CreateNeg(Value *V, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1256
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:685
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:1021
Value * getPointerOperand()
Definition: Instructions.h:274
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:1736
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:1921
This class represents a cast from an integer to a pointer.
const Value * getCondition() const
static Constant * getAllOnesValue(Type *Ty)
Definition: Constants.cpp:322
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:477
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:1963
size_t size() const
Definition: SmallVector.h:53
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:761
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:996
Value * CreateTrunc(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1552
Type * getAllocatedType() const
Return the type that is being allocated by the instruction.
Definition: Instructions.h:106
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:44
signed greater than
Definition: InstrTypes.h:712
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:1866
Value * CreateGEP(Value *Ptr, ArrayRef< Value *> IdxList, const Twine &Name="")
Definition: IRBuilder.h:1374
bool isPtrOrPtrVectorTy() const
Return true if this is a pointer type or a vector of pointer types.
Definition: Type.h:227
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:358
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
auto size(R &&Range, typename std::enable_if< std::is_same< typename std::iterator_traits< decltype(Range.begin())>::iterator_category, std::random_access_iterator_tag >::value, void >::type *=nullptr) -> decltype(std::distance(Range.begin(), Range.end()))
Get the size of a range.
Definition: STLExtras.h:1023
iterator end()
Definition: BasicBlock.h:266
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:213
IterTy arg_begin() const
Definition: CallSite.h:571
Value * CreateIntCast(Value *V, Type *DestTy, bool isSigned, const Twine &Name="")
Definition: IRBuilder.h:1698
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:847
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:1934
Provides information about what library functions are available for the current target.
unsigned getABITypeAlignment(Type *Ty) const
Returns the minimum ABI-required alignment for the specified type.
Definition: DataLayout.cpp:722
bool isAggregateType() const
Return true if the type is an aggregate type.
Definition: Type.h:258
signed less than
Definition: InstrTypes.h:714
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 ...
CallInst * CreateMaskedStore(Value *Val, Value *Ptr, unsigned Align, Value *Mask)
Create a call to Masked Store intrinsic.
Definition: IRBuilder.cpp:492
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:535
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
CallInst * CreateMemCpy(Value *Dst, unsigned DstAlign, Value *Src, unsigned SrcAlign, uint64_t Size, bool isVolatile=false, MDNode *TBAATag=nullptr, MDNode *TBAAStructTag=nullptr, MDNode *ScopeTag=nullptr, MDNode *NoAliasTag=nullptr)
Create and insert a memcpy between the specified pointers.
Definition: IRBuilder.h:446
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:621
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
CallInst * CreateMaskedLoad(Value *Ptr, unsigned Align, Value *Mask, Value *PassThru=nullptr, const Twine &Name="")
Create a call to Masked Load intrinsic.
Definition: IRBuilder.cpp:471
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:133
unsigned getVectorNumElements() const
Definition: DerivedTypes.h:462
signed less or equal
Definition: InstrTypes.h:715
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:56
Class for arbitrary precision integers.
Definition: APInt.h:70
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:1051
const Value * getFalseValue() const
Value * CreatePointerCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1675
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:417
Predicate getPredicate() const
Return the predicate for this instruction.
Definition: InstrTypes.h:759
static cl::opt< bool > ClEnableKmsan("msan-kernel", cl::desc("Enable KernelMemorySanitizer instrumentation"), cl::Hidden, cl::init(false))
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:230
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:56
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
#define N
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.
uint32_t Size
Definition: Profile.cpp:47
void maybeMarkSanitizerLibraryCallNoBuiltin(CallInst *CI, const TargetLibraryInfo *TLI)
Given a CallInst, check if it calls a string function known to CodeGen, and mark it with NoBuiltin if...
Definition: Local.cpp:2785
static 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:1112
Value * CreatePtrToInt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1619
static const unsigned kOriginSize
const std::string to_string(const T &Value)
Definition: ScopedPrinter.h:62
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:1328
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:577
ArrayRef< unsigned > getIndices() const
Module * getParent()
Get the module that this global value is contained inside of...
Definition: GlobalValue.h:566
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
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
AttributeSet getFnAttributes() const
The function attributes are returned.
BasicBlock::iterator GetInsertPoint() const
Definition: IRBuilder.h:122
BasicBlock * SplitBlock(BasicBlock *Old, Instruction *SplitPt, DominatorTree *DT=nullptr, LoopInfo *LI=nullptr, MemorySSAUpdater *MSSAU=nullptr)
Split the specified block at the specified instruction - everything before SplitPt stays in Old and e...
Value * CreateLShr(Value *LHS, Value *RHS, const Twine &Name="", bool isExact=false)
Definition: IRBuilder.h:1072
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))
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:799
static const PlatformMemoryMapParams FreeBSD_X86_MemoryMapParams
Type * getArrayElementType() const
Definition: Type.h:365
FunctionPass * createMemorySanitizerPass(int TrackOrigins=0, bool Recover=false, bool EnableKmsan=false)
Value * CreateInsertValue(Value *Agg, Value *Val, ArrayRef< unsigned > Idxs, const Twine &Name="")
Definition: IRBuilder.h:1971
bool isBigEndian() const
Definition: DataLayout.h:222
#define LLVM_DEBUG(X)
Definition: Debug.h:123
Value * getPointerOperand()
Definition: Instructions.h:402
static IntegerType * getInt8Ty(LLVMContext &C)
Definition: Type.cpp:174
static const char *const kMsanModuleCtorName
static Constant * get(ArrayRef< Constant *> V)
Definition: Constants.cpp:1056
iterator_range< arg_iterator > args()
Definition: Function.h:689
signed greater or equal
Definition: InstrTypes.h:713
bool isArrayTy() const
True if this is an instance of ArrayType.
Definition: Type.h:221
Type * getContainedType(unsigned i) const
This method is used to implement the type iterator (defined at the end of the file).
Definition: Type.h:333
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:1871