1//===- FuzzerTracePC.cpp - PC tracing--------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8// Trace PCs.
9// This module implements __sanitizer_cov_trace_pc_guard[_init],
10// the callback required for -fsanitize-coverage=trace-pc-guard instrumentation.
11//
12//===----------------------------------------------------------------------===//
13
14#include "FuzzerTracePC.h"
15#include "FuzzerBuiltins.h"
16#include "FuzzerBuiltinsMsvc.h"
17#include "FuzzerCorpus.h"
18#include "FuzzerDefs.h"
19#include "FuzzerDictionary.h"
20#include "FuzzerExtFunctions.h"
21#include "FuzzerIO.h"
22#include "FuzzerPlatform.h"
23#include "FuzzerUtil.h"
24#include "FuzzerValueBitMap.h"
25#include <set>
26
27// Used by -fsanitize-coverage=stack-depth to track stack depth
28ATTRIBUTES_INTERFACE_TLS_INITIAL_EXEC uintptr_t __sancov_lowest_stack;
29
30namespace fuzzer {
31
32TracePC TPC;
33
34size_t TracePC::GetTotalPCCoverage() {
35  return ObservedPCs.size();
36}
37
38
39void TracePC::HandleInline8bitCountersInit(uint8_t *Start, uint8_t *Stop) {
40  if (Start == Stop) return;
41  if (NumModules &&
42      Modules[NumModules - 1].Start() == Start)
43    return;
44  assert(NumModules <
45         sizeof(Modules) / sizeof(Modules[0]));
46  auto &M = Modules[NumModules++];
47  uint8_t *AlignedStart = RoundUpByPage(Start);
48  uint8_t *AlignedStop  = RoundDownByPage(Stop);
49  size_t NumFullPages = AlignedStop > AlignedStart ?
50                        (AlignedStop - AlignedStart) / PageSize() : 0;
51  bool NeedFirst = Start < AlignedStart || !NumFullPages;
52  bool NeedLast  = Stop > AlignedStop && AlignedStop >= AlignedStart;
53  M.NumRegions = NumFullPages + NeedFirst + NeedLast;;
54  assert(M.NumRegions > 0);
55  M.Regions = new Module::Region[M.NumRegions];
56  assert(M.Regions);
57  size_t R = 0;
58  if (NeedFirst)
59    M.Regions[R++] = {Start, std::min(Stop, AlignedStart), true, false};
60  for (uint8_t *P = AlignedStart; P < AlignedStop; P += PageSize())
61    M.Regions[R++] = {P, P + PageSize(), true, true};
62  if (NeedLast)
63    M.Regions[R++] = {AlignedStop, Stop, true, false};
64  assert(R == M.NumRegions);
65  assert(M.Size() == (size_t)(Stop - Start));
66  assert(M.Stop() == Stop);
67  assert(M.Start() == Start);
68  NumInline8bitCounters += M.Size();
69}
70
71void TracePC::HandlePCsInit(const uintptr_t *Start, const uintptr_t *Stop) {
72  const PCTableEntry *B = reinterpret_cast<const PCTableEntry *>(Start);
73  const PCTableEntry *E = reinterpret_cast<const PCTableEntry *>(Stop);
74  if (NumPCTables && ModulePCTable[NumPCTables - 1].Start == B) return;
75  assert(NumPCTables < sizeof(ModulePCTable) / sizeof(ModulePCTable[0]));
76  ModulePCTable[NumPCTables++] = {B, E};
77  NumPCsInPCTables += E - B;
78}
79
80void TracePC::PrintModuleInfo() {
81  if (NumModules) {
82    Printf("INFO: Loaded %zd modules   (%zd inline 8-bit counters): ",
83           NumModules, NumInline8bitCounters);
84    for (size_t i = 0; i < NumModules; i++)
85      Printf("%zd [%p, %p), ", Modules[i].Size(), Modules[i].Start(),
86             Modules[i].Stop());
87    Printf("\n");
88  }
89  if (NumPCTables) {
90    Printf("INFO: Loaded %zd PC tables (%zd PCs): ", NumPCTables,
91           NumPCsInPCTables);
92    for (size_t i = 0; i < NumPCTables; i++) {
93      Printf("%zd [%p,%p), ", ModulePCTable[i].Stop - ModulePCTable[i].Start,
94             ModulePCTable[i].Start, ModulePCTable[i].Stop);
95    }
96    Printf("\n");
97
98    if (NumInline8bitCounters && NumInline8bitCounters != NumPCsInPCTables) {
99      Printf("ERROR: The size of coverage PC tables does not match the\n"
100             "number of instrumented PCs. This might be a compiler bug,\n"
101             "please contact the libFuzzer developers.\n"
102             "Also check https://bugs.llvm.org/show_bug.cgi?id=34636\n"
103             "for possible workarounds (tl;dr: don't use the old GNU ld)\n");
104      _Exit(1);
105    }
106  }
107  if (size_t NumExtraCounters = ExtraCountersEnd() - ExtraCountersBegin())
108    Printf("INFO: %zd Extra Counters\n", NumExtraCounters);
109
110  size_t MaxFeatures = CollectFeatures([](uint32_t) {});
111  if (MaxFeatures > std::numeric_limits<uint32_t>::max())
112    Printf("WARNING: The coverage PC tables may produce up to %zu features.\n"
113           "This exceeds the maximum 32-bit value. Some features may be\n"
114           "ignored, and fuzzing may become less precise. If possible,\n"
115           "consider refactoring the fuzzer into several smaller fuzzers\n"
116           "linked against only a portion of the current target.\n",
117           MaxFeatures);
118}
119
120ATTRIBUTE_NO_SANITIZE_ALL
121void TracePC::HandleCallerCallee(uintptr_t Caller, uintptr_t Callee) {
122  const uintptr_t kBits = 12;
123  const uintptr_t kMask = (1 << kBits) - 1;
124  uintptr_t Idx = (Caller & kMask) | ((Callee & kMask) << kBits);
125  ValueProfileMap.AddValueModPrime(Idx);
126}
127
128/// \return the address of the previous instruction.
129/// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.h`
130inline ALWAYS_INLINE uintptr_t GetPreviousInstructionPc(uintptr_t PC) {
131#if defined(__arm__)
132  // T32 (Thumb) branch instructions might be 16 or 32 bit long,
133  // so we return (pc-2) in that case in order to be safe.
134  // For A32 mode we return (pc-4) because all instructions are 32 bit long.
135  return (PC - 3) & (~1);
136#elif defined(__sparc__) || defined(__mips__)
137  return PC - 8;
138#elif defined(__riscv__)
139  return PC - 2;
140#elif defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64)
141  return PC - 1;
142#else
143  return PC - 4;
144#endif
145}
146
147/// \return the address of the next instruction.
148/// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.cpp`
149ALWAYS_INLINE uintptr_t TracePC::GetNextInstructionPc(uintptr_t PC) {
150#if defined(__mips__)
151  return PC + 8;
152#elif defined(__powerpc__) || defined(__sparc__) || defined(__arm__) ||        \
153    defined(__aarch64__) || defined(__loongarch__)
154  return PC + 4;
155#else
156  return PC + 1;
157#endif
158}
159
160void TracePC::UpdateObservedPCs() {
161  std::vector<uintptr_t> CoveredFuncs;
162  auto ObservePC = [&](const PCTableEntry *TE) {
163    if (ObservedPCs.insert(TE).second && DoPrintNewPCs) {
164      PrintPC("\tNEW_PC: %p %F %L", "\tNEW_PC: %p",
165              GetNextInstructionPc(TE->PC));
166      Printf("\n");
167    }
168  };
169
170  auto Observe = [&](const PCTableEntry *TE) {
171    if (PcIsFuncEntry(TE))
172      if (++ObservedFuncs[TE->PC] == 1 && NumPrintNewFuncs)
173        CoveredFuncs.push_back(TE->PC);
174    ObservePC(TE);
175  };
176
177  if (NumPCsInPCTables) {
178    if (NumInline8bitCounters == NumPCsInPCTables) {
179      for (size_t i = 0; i < NumModules; i++) {
180        auto &M = Modules[i];
181        assert(M.Size() ==
182               (size_t)(ModulePCTable[i].Stop - ModulePCTable[i].Start));
183        for (size_t r = 0; r < M.NumRegions; r++) {
184          auto &R = M.Regions[r];
185          if (!R.Enabled) continue;
186          for (uint8_t *P = R.Start; P < R.Stop; P++)
187            if (*P)
188              Observe(&ModulePCTable[i].Start[M.Idx(P)]);
189        }
190      }
191    }
192  }
193
194  for (size_t i = 0, N = Min(CoveredFuncs.size(), NumPrintNewFuncs); i < N;
195       i++) {
196    Printf("\tNEW_FUNC[%zd/%zd]: ", i + 1, CoveredFuncs.size());
197    PrintPC("%p %F %L", "%p", GetNextInstructionPc(CoveredFuncs[i]));
198    Printf("\n");
199  }
200}
201
202uintptr_t TracePC::PCTableEntryIdx(const PCTableEntry *TE) {
203  size_t TotalTEs = 0;
204  for (size_t i = 0; i < NumPCTables; i++) {
205    auto &M = ModulePCTable[i];
206    if (TE >= M.Start && TE < M.Stop)
207      return TotalTEs + TE - M.Start;
208    TotalTEs += M.Stop - M.Start;
209  }
210  assert(0);
211  return 0;
212}
213
214const TracePC::PCTableEntry *TracePC::PCTableEntryByIdx(uintptr_t Idx) {
215  for (size_t i = 0; i < NumPCTables; i++) {
216    auto &M = ModulePCTable[i];
217    size_t Size = M.Stop - M.Start;
218    if (Idx < Size) return &M.Start[Idx];
219    Idx -= Size;
220  }
221  return nullptr;
222}
223
224static std::string GetModuleName(uintptr_t PC) {
225  char ModulePathRaw[4096] = "";  // What's PATH_MAX in portable C++?
226  void *OffsetRaw = nullptr;
227  if (!EF->__sanitizer_get_module_and_offset_for_pc(
228      reinterpret_cast<void *>(PC), ModulePathRaw,
229      sizeof(ModulePathRaw), &OffsetRaw))
230    return "";
231  return ModulePathRaw;
232}
233
234template<class CallBack>
235void TracePC::IterateCoveredFunctions(CallBack CB) {
236  for (size_t i = 0; i < NumPCTables; i++) {
237    auto &M = ModulePCTable[i];
238    assert(M.Start < M.Stop);
239    auto ModuleName = GetModuleName(M.Start->PC);
240    for (auto NextFE = M.Start; NextFE < M.Stop; ) {
241      auto FE = NextFE;
242      assert(PcIsFuncEntry(FE) && "Not a function entry point");
243      do {
244        NextFE++;
245      } while (NextFE < M.Stop && !(PcIsFuncEntry(NextFE)));
246      CB(FE, NextFE, ObservedFuncs[FE->PC]);
247    }
248  }
249}
250
251void TracePC::SetFocusFunction(const std::string &FuncName) {
252  // This function should be called once.
253  assert(!FocusFunctionCounterPtr);
254  // "auto" is not a valid function name. If this function is called with "auto"
255  // that means the auto focus functionality failed.
256  if (FuncName.empty() || FuncName == "auto")
257    return;
258  for (size_t M = 0; M < NumModules; M++) {
259    auto &PCTE = ModulePCTable[M];
260    size_t N = PCTE.Stop - PCTE.Start;
261    for (size_t I = 0; I < N; I++) {
262      if (!(PcIsFuncEntry(&PCTE.Start[I]))) continue;  // not a function entry.
263      auto Name = DescribePC("%F", GetNextInstructionPc(PCTE.Start[I].PC));
264      if (Name[0] == 'i' && Name[1] == 'n' && Name[2] == ' ')
265        Name = Name.substr(3, std::string::npos);
266      if (FuncName != Name) continue;
267      Printf("INFO: Focus function is set to '%s'\n", Name.c_str());
268      FocusFunctionCounterPtr = Modules[M].Start() + I;
269      return;
270    }
271  }
272
273  Printf("ERROR: Failed to set focus function. Make sure the function name is "
274         "valid (%s) and symbolization is enabled.\n", FuncName.c_str());
275  exit(1);
276}
277
278bool TracePC::ObservedFocusFunction() {
279  return FocusFunctionCounterPtr && *FocusFunctionCounterPtr;
280}
281
282void TracePC::PrintCoverage(bool PrintAllCounters) {
283  if (!EF->__sanitizer_symbolize_pc ||
284      !EF->__sanitizer_get_module_and_offset_for_pc) {
285    Printf("INFO: __sanitizer_symbolize_pc or "
286           "__sanitizer_get_module_and_offset_for_pc is not available,"
287           " not printing coverage\n");
288    return;
289  }
290  Printf(PrintAllCounters ? "FULL COVERAGE:\n" : "COVERAGE:\n");
291  auto CoveredFunctionCallback = [&](const PCTableEntry *First,
292                                     const PCTableEntry *Last,
293                                     uintptr_t Counter) {
294    assert(First < Last);
295    auto VisualizePC = GetNextInstructionPc(First->PC);
296    std::string FileStr = DescribePC("%s", VisualizePC);
297    if (!IsInterestingCoverageFile(FileStr))
298      return;
299    std::string FunctionStr = DescribePC("%F", VisualizePC);
300    if (FunctionStr.find("in ") == 0)
301      FunctionStr = FunctionStr.substr(3);
302    std::string LineStr = DescribePC("%l", VisualizePC);
303    size_t NumEdges = Last - First;
304    std::vector<uintptr_t> UncoveredPCs;
305    std::vector<uintptr_t> CoveredPCs;
306    for (auto TE = First; TE < Last; TE++)
307      if (!ObservedPCs.count(TE))
308        UncoveredPCs.push_back(TE->PC);
309      else
310        CoveredPCs.push_back(TE->PC);
311
312    if (PrintAllCounters) {
313      Printf("U");
314      for (auto PC : UncoveredPCs)
315        Printf(DescribePC(" %l", GetNextInstructionPc(PC)).c_str());
316      Printf("\n");
317
318      Printf("C");
319      for (auto PC : CoveredPCs)
320        Printf(DescribePC(" %l", GetNextInstructionPc(PC)).c_str());
321      Printf("\n");
322    } else {
323      Printf("%sCOVERED_FUNC: hits: %zd", Counter ? "" : "UN", Counter);
324      Printf(" edges: %zd/%zd", NumEdges - UncoveredPCs.size(), NumEdges);
325      Printf(" %s %s:%s\n", FunctionStr.c_str(), FileStr.c_str(),
326             LineStr.c_str());
327      if (Counter)
328        for (auto PC : UncoveredPCs)
329          Printf("  UNCOVERED_PC: %s\n",
330                 DescribePC("%s:%l", GetNextInstructionPc(PC)).c_str());
331    }
332  };
333
334  IterateCoveredFunctions(CoveredFunctionCallback);
335}
336
337// Value profile.
338// We keep track of various values that affect control flow.
339// These values are inserted into a bit-set-based hash map.
340// Every new bit in the map is treated as a new coverage.
341//
342// For memcmp/strcmp/etc the interesting value is the length of the common
343// prefix of the parameters.
344// For cmp instructions the interesting value is a XOR of the parameters.
345// The interesting value is mixed up with the PC and is then added to the map.
346
347ATTRIBUTE_NO_SANITIZE_ALL
348void TracePC::AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2,
349                                size_t n, bool StopAtZero) {
350  if (!n) return;
351  size_t Len = std::min(n, Word::GetMaxSize());
352  const uint8_t *A1 = reinterpret_cast<const uint8_t *>(s1);
353  const uint8_t *A2 = reinterpret_cast<const uint8_t *>(s2);
354  uint8_t B1[Word::kMaxSize];
355  uint8_t B2[Word::kMaxSize];
356  // Copy the data into locals in this non-msan-instrumented function
357  // to avoid msan complaining further.
358  size_t Hash = 0;  // Compute some simple hash of both strings.
359  for (size_t i = 0; i < Len; i++) {
360    B1[i] = A1[i];
361    B2[i] = A2[i];
362    size_t T = B1[i];
363    Hash ^= (T << 8) | B2[i];
364  }
365  size_t I = 0;
366  uint8_t HammingDistance = 0;
367  for (; I < Len; I++) {
368    if (B1[I] != B2[I] || (StopAtZero && B1[I] == 0)) {
369      HammingDistance = static_cast<uint8_t>(Popcountll(B1[I] ^ B2[I]));
370      break;
371    }
372  }
373  size_t PC = reinterpret_cast<size_t>(caller_pc);
374  size_t Idx = (PC & 4095) | (I << 12);
375  Idx += HammingDistance;
376  ValueProfileMap.AddValue(Idx);
377  TORCW.Insert(Idx ^ Hash, Word(B1, Len), Word(B2, Len));
378}
379
380template <class T>
381ATTRIBUTE_TARGET_POPCNT ALWAYS_INLINE
382ATTRIBUTE_NO_SANITIZE_ALL
383void TracePC::HandleCmp(uintptr_t PC, T Arg1, T Arg2) {
384  uint64_t ArgXor = Arg1 ^ Arg2;
385  if (sizeof(T) == 4)
386      TORC4.Insert(ArgXor, Arg1, Arg2);
387  else if (sizeof(T) == 8)
388      TORC8.Insert(ArgXor, Arg1, Arg2);
389  uint64_t HammingDistance = Popcountll(ArgXor);  // [0,64]
390  uint64_t AbsoluteDistance = (Arg1 == Arg2 ? 0 : Clzll(Arg1 - Arg2) + 1);
391  ValueProfileMap.AddValue(PC * 128 + HammingDistance);
392  ValueProfileMap.AddValue(PC * 128 + 64 + AbsoluteDistance);
393}
394
395ATTRIBUTE_NO_SANITIZE_MEMORY
396static size_t InternalStrnlen(const char *S, size_t MaxLen) {
397  size_t Len = 0;
398  for (; Len < MaxLen && S[Len]; Len++) {}
399  return Len;
400}
401
402// Finds min of (strlen(S1), strlen(S2)).
403// Needed because one of these strings may actually be non-zero terminated.
404ATTRIBUTE_NO_SANITIZE_MEMORY
405static size_t InternalStrnlen2(const char *S1, const char *S2) {
406  size_t Len = 0;
407  for (; S1[Len] && S2[Len]; Len++)  {}
408  return Len;
409}
410
411void TracePC::ClearInlineCounters() {
412  IterateCounterRegions([](const Module::Region &R){
413    if (R.Enabled)
414      memset(R.Start, 0, R.Stop - R.Start);
415  });
416}
417
418ATTRIBUTE_NO_SANITIZE_ALL
419void TracePC::RecordInitialStack() {
420  int stack;
421  __sancov_lowest_stack = InitialStack = reinterpret_cast<uintptr_t>(&stack);
422}
423
424uintptr_t TracePC::GetMaxStackOffset() const {
425  return InitialStack - __sancov_lowest_stack;  // Stack grows down
426}
427
428void WarnAboutDeprecatedInstrumentation(const char *flag) {
429  // Use RawPrint because Printf cannot be used on Windows before OutputFile is
430  // initialized.
431  RawPrint(flag);
432  RawPrint(
433      " is no longer supported by libFuzzer.\n"
434      "Please either migrate to a compiler that supports -fsanitize=fuzzer\n"
435      "or use an older version of libFuzzer\n");
436  exit(1);
437}
438
439} // namespace fuzzer
440
441extern "C" {
442ATTRIBUTE_INTERFACE
443ATTRIBUTE_NO_SANITIZE_ALL
444void __sanitizer_cov_trace_pc_guard(uint32_t *Guard) {
445  fuzzer::WarnAboutDeprecatedInstrumentation(
446      "-fsanitize-coverage=trace-pc-guard");
447}
448
449// Best-effort support for -fsanitize-coverage=trace-pc, which is available
450// in both Clang and GCC.
451ATTRIBUTE_INTERFACE
452ATTRIBUTE_NO_SANITIZE_ALL
453void __sanitizer_cov_trace_pc() {
454  fuzzer::WarnAboutDeprecatedInstrumentation("-fsanitize-coverage=trace-pc");
455}
456
457ATTRIBUTE_INTERFACE
458void __sanitizer_cov_trace_pc_guard_init(uint32_t *Start, uint32_t *Stop) {
459  fuzzer::WarnAboutDeprecatedInstrumentation(
460      "-fsanitize-coverage=trace-pc-guard");
461}
462
463ATTRIBUTE_INTERFACE
464void __sanitizer_cov_8bit_counters_init(uint8_t *Start, uint8_t *Stop) {
465  fuzzer::TPC.HandleInline8bitCountersInit(Start, Stop);
466}
467
468ATTRIBUTE_INTERFACE
469void __sanitizer_cov_pcs_init(const uintptr_t *pcs_beg,
470                              const uintptr_t *pcs_end) {
471  fuzzer::TPC.HandlePCsInit(pcs_beg, pcs_end);
472}
473
474ATTRIBUTE_INTERFACE
475ATTRIBUTE_NO_SANITIZE_ALL
476void __sanitizer_cov_trace_pc_indir(uintptr_t Callee) {
477  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
478  fuzzer::TPC.HandleCallerCallee(PC, Callee);
479}
480
481ATTRIBUTE_INTERFACE
482ATTRIBUTE_NO_SANITIZE_ALL
483ATTRIBUTE_TARGET_POPCNT
484void __sanitizer_cov_trace_cmp8(uint64_t Arg1, uint64_t Arg2) {
485  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
486  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
487}
488
489ATTRIBUTE_INTERFACE
490ATTRIBUTE_NO_SANITIZE_ALL
491ATTRIBUTE_TARGET_POPCNT
492// Now the __sanitizer_cov_trace_const_cmp[1248] callbacks just mimic
493// the behaviour of __sanitizer_cov_trace_cmp[1248] ones. This, however,
494// should be changed later to make full use of instrumentation.
495void __sanitizer_cov_trace_const_cmp8(uint64_t Arg1, uint64_t Arg2) {
496  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
497  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
498}
499
500ATTRIBUTE_INTERFACE
501ATTRIBUTE_NO_SANITIZE_ALL
502ATTRIBUTE_TARGET_POPCNT
503void __sanitizer_cov_trace_cmp4(uint32_t Arg1, uint32_t Arg2) {
504  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
505  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
506}
507
508ATTRIBUTE_INTERFACE
509ATTRIBUTE_NO_SANITIZE_ALL
510ATTRIBUTE_TARGET_POPCNT
511void __sanitizer_cov_trace_const_cmp4(uint32_t Arg1, uint32_t Arg2) {
512  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
513  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
514}
515
516ATTRIBUTE_INTERFACE
517ATTRIBUTE_NO_SANITIZE_ALL
518ATTRIBUTE_TARGET_POPCNT
519void __sanitizer_cov_trace_cmp2(uint16_t Arg1, uint16_t Arg2) {
520  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
521  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
522}
523
524ATTRIBUTE_INTERFACE
525ATTRIBUTE_NO_SANITIZE_ALL
526ATTRIBUTE_TARGET_POPCNT
527void __sanitizer_cov_trace_const_cmp2(uint16_t Arg1, uint16_t Arg2) {
528  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
529  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
530}
531
532ATTRIBUTE_INTERFACE
533ATTRIBUTE_NO_SANITIZE_ALL
534ATTRIBUTE_TARGET_POPCNT
535void __sanitizer_cov_trace_cmp1(uint8_t Arg1, uint8_t Arg2) {
536  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
537  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
538}
539
540ATTRIBUTE_INTERFACE
541ATTRIBUTE_NO_SANITIZE_ALL
542ATTRIBUTE_TARGET_POPCNT
543void __sanitizer_cov_trace_const_cmp1(uint8_t Arg1, uint8_t Arg2) {
544  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
545  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
546}
547
548ATTRIBUTE_INTERFACE
549ATTRIBUTE_NO_SANITIZE_ALL
550ATTRIBUTE_TARGET_POPCNT
551void __sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases) {
552  uint64_t N = Cases[0];
553  uint64_t ValSizeInBits = Cases[1];
554  uint64_t *Vals = Cases + 2;
555  // Skip the most common and the most boring case: all switch values are small.
556  // We may want to skip this at compile-time, but it will make the
557  // instrumentation less general.
558  if (Vals[N - 1]  < 256)
559    return;
560  // Also skip small inputs values, they won't give good signal.
561  if (Val < 256)
562    return;
563  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
564  size_t i;
565  uint64_t Smaller = 0;
566  uint64_t Larger = ~(uint64_t)0;
567  // Find two switch values such that Smaller < Val < Larger.
568  // Use 0 and 0xfff..f as the defaults.
569  for (i = 0; i < N; i++) {
570    if (Val < Vals[i]) {
571      Larger = Vals[i];
572      break;
573    }
574    if (Val > Vals[i]) Smaller = Vals[i];
575  }
576
577  // Apply HandleCmp to {Val,Smaller} and {Val, Larger},
578  // use i as the PC modifier for HandleCmp.
579  if (ValSizeInBits == 16) {
580    fuzzer::TPC.HandleCmp(PC + 2 * i, static_cast<uint16_t>(Val),
581                          (uint16_t)(Smaller));
582    fuzzer::TPC.HandleCmp(PC + 2 * i + 1, static_cast<uint16_t>(Val),
583                          (uint16_t)(Larger));
584  } else if (ValSizeInBits == 32) {
585    fuzzer::TPC.HandleCmp(PC + 2 * i, static_cast<uint32_t>(Val),
586                          (uint32_t)(Smaller));
587    fuzzer::TPC.HandleCmp(PC + 2 * i + 1, static_cast<uint32_t>(Val),
588                          (uint32_t)(Larger));
589  } else {
590    fuzzer::TPC.HandleCmp(PC + 2*i, Val, Smaller);
591    fuzzer::TPC.HandleCmp(PC + 2*i + 1, Val, Larger);
592  }
593}
594
595ATTRIBUTE_INTERFACE
596ATTRIBUTE_NO_SANITIZE_ALL
597ATTRIBUTE_TARGET_POPCNT
598void __sanitizer_cov_trace_div4(uint32_t Val) {
599  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
600  fuzzer::TPC.HandleCmp(PC, Val, (uint32_t)0);
601}
602
603ATTRIBUTE_INTERFACE
604ATTRIBUTE_NO_SANITIZE_ALL
605ATTRIBUTE_TARGET_POPCNT
606void __sanitizer_cov_trace_div8(uint64_t Val) {
607  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
608  fuzzer::TPC.HandleCmp(PC, Val, (uint64_t)0);
609}
610
611ATTRIBUTE_INTERFACE
612ATTRIBUTE_NO_SANITIZE_ALL
613ATTRIBUTE_TARGET_POPCNT
614void __sanitizer_cov_trace_gep(uintptr_t Idx) {
615  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
616  fuzzer::TPC.HandleCmp(PC, Idx, (uintptr_t)0);
617}
618
619ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
620void __sanitizer_weak_hook_memcmp(void *caller_pc, const void *s1,
621                                  const void *s2, size_t n, int result) {
622  if (!fuzzer::RunningUserCallback) return;
623  if (result == 0) return;  // No reason to mutate.
624  if (n <= 1) return;  // Not interesting.
625  fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n, /*StopAtZero*/false);
626}
627
628ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
629void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1,
630                                   const char *s2, size_t n, int result) {
631  if (!fuzzer::RunningUserCallback) return;
632  if (result == 0) return;  // No reason to mutate.
633  size_t Len1 = fuzzer::InternalStrnlen(s1, n);
634  size_t Len2 = fuzzer::InternalStrnlen(s2, n);
635  n = std::min(n, Len1);
636  n = std::min(n, Len2);
637  if (n <= 1) return;  // Not interesting.
638  fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n, /*StopAtZero*/true);
639}
640
641ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
642void __sanitizer_weak_hook_strcmp(void *caller_pc, const char *s1,
643                                   const char *s2, int result) {
644  if (!fuzzer::RunningUserCallback) return;
645  if (result == 0) return;  // No reason to mutate.
646  size_t N = fuzzer::InternalStrnlen2(s1, s2);
647  if (N <= 1) return;  // Not interesting.
648  fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, N, /*StopAtZero*/true);
649}
650
651ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
652void __sanitizer_weak_hook_strncasecmp(void *called_pc, const char *s1,
653                                       const char *s2, size_t n, int result) {
654  if (!fuzzer::RunningUserCallback) return;
655  return __sanitizer_weak_hook_strncmp(called_pc, s1, s2, n, result);
656}
657
658ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
659void __sanitizer_weak_hook_strcasecmp(void *called_pc, const char *s1,
660                                      const char *s2, int result) {
661  if (!fuzzer::RunningUserCallback) return;
662  return __sanitizer_weak_hook_strcmp(called_pc, s1, s2, result);
663}
664
665ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
666void __sanitizer_weak_hook_strstr(void *called_pc, const char *s1,
667                                  const char *s2, char *result) {
668  if (!fuzzer::RunningUserCallback) return;
669  fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), strlen(s2));
670}
671
672ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
673void __sanitizer_weak_hook_strcasestr(void *called_pc, const char *s1,
674                                      const char *s2, char *result) {
675  if (!fuzzer::RunningUserCallback) return;
676  fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), strlen(s2));
677}
678
679ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
680void __sanitizer_weak_hook_memmem(void *called_pc, const void *s1, size_t len1,
681                                  const void *s2, size_t len2, void *result) {
682  if (!fuzzer::RunningUserCallback) return;
683  fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), len2);
684}
685}  // extern "C"
686