FuzzerTracePC.cpp revision 360784
1193640Sariff//===- FuzzerTracePC.cpp - PC tracing--------------------------------------===//
2193640Sariff//
3193640Sariff// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4193640Sariff// See https://llvm.org/LICENSE.txt for license information.
5193640Sariff// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6193640Sariff//
7193640Sariff//===----------------------------------------------------------------------===//
8193640Sariff// Trace PCs.
9193640Sariff// This module implements __sanitizer_cov_trace_pc_guard[_init],
10193640Sariff// the callback required for -fsanitize-coverage=trace-pc-guard instrumentation.
11193640Sariff//
12193640Sariff//===----------------------------------------------------------------------===//
13193640Sariff
14193640Sariff#include "FuzzerTracePC.h"
15193640Sariff#include "FuzzerBuiltins.h"
16193640Sariff#include "FuzzerBuiltinsMsvc.h"
17193640Sariff#include "FuzzerCorpus.h"
18193640Sariff#include "FuzzerDefs.h"
19193640Sariff#include "FuzzerDictionary.h"
20193640Sariff#include "FuzzerExtFunctions.h"
21193640Sariff#include "FuzzerIO.h"
22193640Sariff#include "FuzzerUtil.h"
23193640Sariff#include "FuzzerValueBitMap.h"
24193640Sariff#include <set>
25193640Sariff
26193640Sariff// Used by -fsanitize-coverage=stack-depth to track stack depth
27193640SariffATTRIBUTES_INTERFACE_TLS_INITIAL_EXEC uintptr_t __sancov_lowest_stack;
28193640Sariff
29193640Sariffnamespace fuzzer {
30193640Sariff
31193640SariffTracePC TPC;
32193640Sariff
33193640Sariffsize_t TracePC::GetTotalPCCoverage() {
34193640Sariff  return ObservedPCs.size();
35193640Sariff}
36193640Sariff
37193640Sariff
38193640Sariffvoid TracePC::HandleInline8bitCountersInit(uint8_t *Start, uint8_t *Stop) {
39193640Sariff  if (Start == Stop) return;
40193640Sariff  if (NumModules &&
41193640Sariff      Modules[NumModules - 1].Start() == Start)
42193640Sariff    return;
43193640Sariff  assert(NumModules <
44193640Sariff         sizeof(Modules) / sizeof(Modules[0]));
45193640Sariff  auto &M = Modules[NumModules++];
46193640Sariff  uint8_t *AlignedStart = RoundUpByPage(Start);
47193640Sariff  uint8_t *AlignedStop  = RoundDownByPage(Stop);
48193640Sariff  size_t NumFullPages = AlignedStop > AlignedStart ?
49193640Sariff                        (AlignedStop - AlignedStart) / PageSize() : 0;
50193640Sariff  bool NeedFirst = Start < AlignedStart || !NumFullPages;
51193640Sariff  bool NeedLast  = Stop > AlignedStop && AlignedStop >= AlignedStart;
52193640Sariff  M.NumRegions = NumFullPages + NeedFirst + NeedLast;;
53193640Sariff  assert(M.NumRegions > 0);
54193640Sariff  M.Regions = new Module::Region[M.NumRegions];
55193640Sariff  assert(M.Regions);
56193640Sariff  size_t R = 0;
57193640Sariff  if (NeedFirst)
58193640Sariff    M.Regions[R++] = {Start, std::min(Stop, AlignedStart), true, false};
59193640Sariff  for (uint8_t *P = AlignedStart; P < AlignedStop; P += PageSize())
60193640Sariff    M.Regions[R++] = {P, P + PageSize(), true, true};
61193640Sariff  if (NeedLast)
62193640Sariff    M.Regions[R++] = {AlignedStop, Stop, true, false};
63193640Sariff  assert(R == M.NumRegions);
64193640Sariff  assert(M.Size() == (size_t)(Stop - Start));
65193640Sariff  assert(M.Stop() == Stop);
66193640Sariff  assert(M.Start() == Start);
67193640Sariff  NumInline8bitCounters += M.Size();
68193640Sariff}
69193640Sariff
70193640Sariffvoid TracePC::HandlePCsInit(const uintptr_t *Start, const uintptr_t *Stop) {
71193640Sariff  const PCTableEntry *B = reinterpret_cast<const PCTableEntry *>(Start);
72193640Sariff  const PCTableEntry *E = reinterpret_cast<const PCTableEntry *>(Stop);
73193640Sariff  if (NumPCTables && ModulePCTable[NumPCTables - 1].Start == B) return;
74193640Sariff  assert(NumPCTables < sizeof(ModulePCTable) / sizeof(ModulePCTable[0]));
75193640Sariff  ModulePCTable[NumPCTables++] = {B, E};
76193640Sariff  NumPCsInPCTables += E - B;
77193640Sariff}
78193640Sariff
79193640Sariffvoid TracePC::PrintModuleInfo() {
80193640Sariff  if (NumModules) {
81193640Sariff    Printf("INFO: Loaded %zd modules   (%zd inline 8-bit counters): ",
82193640Sariff           NumModules, NumInline8bitCounters);
83193640Sariff    for (size_t i = 0; i < NumModules; i++)
84193640Sariff      Printf("%zd [%p, %p), ", Modules[i].Size(), Modules[i].Start(),
85193640Sariff             Modules[i].Stop());
86193640Sariff    Printf("\n");
87193640Sariff  }
88193640Sariff  if (NumPCTables) {
89193640Sariff    Printf("INFO: Loaded %zd PC tables (%zd PCs): ", NumPCTables,
90193640Sariff           NumPCsInPCTables);
91193640Sariff    for (size_t i = 0; i < NumPCTables; i++) {
92193640Sariff      Printf("%zd [%p,%p), ", ModulePCTable[i].Stop - ModulePCTable[i].Start,
93193640Sariff             ModulePCTable[i].Start, ModulePCTable[i].Stop);
94193640Sariff    }
95193640Sariff    Printf("\n");
96193640Sariff
97193640Sariff    if (NumInline8bitCounters && NumInline8bitCounters != NumPCsInPCTables) {
98193640Sariff      Printf("ERROR: The size of coverage PC tables does not match the\n"
99193640Sariff             "number of instrumented PCs. This might be a compiler bug,\n"
100193640Sariff             "please contact the libFuzzer developers.\n"
101193640Sariff             "Also check https://bugs.llvm.org/show_bug.cgi?id=34636\n"
102193640Sariff             "for possible workarounds (tl;dr: don't use the old GNU ld)\n");
103193640Sariff      _Exit(1);
104193640Sariff    }
105193640Sariff  }
106193640Sariff  if (size_t NumExtraCounters = ExtraCountersEnd() - ExtraCountersBegin())
107193640Sariff    Printf("INFO: %zd Extra Counters\n", NumExtraCounters);
108193640Sariff}
109193640Sariff
110193640SariffATTRIBUTE_NO_SANITIZE_ALL
111193640Sariffvoid TracePC::HandleCallerCallee(uintptr_t Caller, uintptr_t Callee) {
112193640Sariff  const uintptr_t kBits = 12;
113193640Sariff  const uintptr_t kMask = (1 << kBits) - 1;
114193640Sariff  uintptr_t Idx = (Caller & kMask) | ((Callee & kMask) << kBits);
115193640Sariff  ValueProfileMap.AddValueModPrime(Idx);
116193640Sariff}
117193640Sariff
118193640Sariff/// \return the address of the previous instruction.
119193640Sariff/// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.h`
120193640Sariffinline ALWAYS_INLINE uintptr_t GetPreviousInstructionPc(uintptr_t PC) {
121193640Sariff#if defined(__arm__)
122193640Sariff  // T32 (Thumb) branch instructions might be 16 or 32 bit long,
123193640Sariff  // so we return (pc-2) in that case in order to be safe.
124193640Sariff  // For A32 mode we return (pc-4) because all instructions are 32 bit long.
125193640Sariff  return (PC - 3) & (~1);
126193640Sariff#elif defined(__powerpc__) || defined(__powerpc64__) || defined(__aarch64__)
127193640Sariff  // PCs are always 4 byte aligned.
128193640Sariff  return PC - 4;
129193640Sariff#elif defined(__sparc__) || defined(__mips__)
130193640Sariff  return PC - 8;
131193640Sariff#else
132193640Sariff  return PC - 1;
133193640Sariff#endif
134193640Sariff}
135193640Sariff
136193640Sariff/// \return the address of the next instruction.
137193640Sariff/// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.cpp`
138193640SariffALWAYS_INLINE uintptr_t TracePC::GetNextInstructionPc(uintptr_t PC) {
139193640Sariff#if defined(__mips__)
140193640Sariff  return PC + 8;
141193640Sariff#elif defined(__powerpc__) || defined(__sparc__) || defined(__arm__) || \
142193640Sariff    defined(__aarch64__)
143193640Sariff  return PC + 4;
144193640Sariff#else
145193640Sariff  return PC + 1;
146193640Sariff#endif
147193640Sariff}
148193640Sariff
149193640Sariffvoid TracePC::UpdateObservedPCs() {
150193640Sariff  Vector<uintptr_t> CoveredFuncs;
151193640Sariff  auto ObservePC = [&](const PCTableEntry *TE) {
152193640Sariff    if (ObservedPCs.insert(TE).second && DoPrintNewPCs) {
153193640Sariff      PrintPC("\tNEW_PC: %p %F %L", "\tNEW_PC: %p",
154193640Sariff              GetNextInstructionPc(TE->PC));
155193640Sariff      Printf("\n");
156193640Sariff    }
157193640Sariff  };
158193640Sariff
159193640Sariff  auto Observe = [&](const PCTableEntry *TE) {
160193640Sariff    if (PcIsFuncEntry(TE))
161193640Sariff      if (++ObservedFuncs[TE->PC] == 1 && NumPrintNewFuncs)
162193640Sariff        CoveredFuncs.push_back(TE->PC);
163193640Sariff    ObservePC(TE);
164193640Sariff  };
165193640Sariff
166193640Sariff  if (NumPCsInPCTables) {
167193640Sariff    if (NumInline8bitCounters == NumPCsInPCTables) {
168193640Sariff      for (size_t i = 0; i < NumModules; i++) {
169193640Sariff        auto &M = Modules[i];
170193640Sariff        assert(M.Size() ==
171193640Sariff               (size_t)(ModulePCTable[i].Stop - ModulePCTable[i].Start));
172193640Sariff        for (size_t r = 0; r < M.NumRegions; r++) {
173193640Sariff          auto &R = M.Regions[r];
174193640Sariff          if (!R.Enabled) continue;
175193640Sariff          for (uint8_t *P = R.Start; P < R.Stop; P++)
176193640Sariff            if (*P)
177193640Sariff              Observe(&ModulePCTable[i].Start[M.Idx(P)]);
178193640Sariff        }
179193640Sariff      }
180193640Sariff    }
181193640Sariff  }
182193640Sariff
183193640Sariff  for (size_t i = 0, N = Min(CoveredFuncs.size(), NumPrintNewFuncs); i < N;
184193640Sariff       i++) {
185193640Sariff    Printf("\tNEW_FUNC[%zd/%zd]: ", i + 1, CoveredFuncs.size());
186193640Sariff    PrintPC("%p %F %L", "%p", GetNextInstructionPc(CoveredFuncs[i]));
187193640Sariff    Printf("\n");
188193640Sariff  }
189193640Sariff}
190193640Sariff
191193640Sariffuintptr_t TracePC::PCTableEntryIdx(const PCTableEntry *TE) {
192193640Sariff  size_t TotalTEs = 0;
193193640Sariff  for (size_t i = 0; i < NumPCTables; i++) {
194193640Sariff    auto &M = ModulePCTable[i];
195193640Sariff    if (TE >= M.Start && TE < M.Stop)
196193640Sariff      return TotalTEs + TE - M.Start;
197193640Sariff    TotalTEs += M.Stop - M.Start;
198193640Sariff  }
199193640Sariff  assert(0);
200193640Sariff  return 0;
201193640Sariff}
202193640Sariff
203193640Sariffconst TracePC::PCTableEntry *TracePC::PCTableEntryByIdx(uintptr_t Idx) {
204193640Sariff  for (size_t i = 0; i < NumPCTables; i++) {
205193640Sariff    auto &M = ModulePCTable[i];
206193640Sariff    size_t Size = M.Stop - M.Start;
207193640Sariff    if (Idx < Size) return &M.Start[Idx];
208193640Sariff    Idx -= Size;
209193640Sariff  }
210193640Sariff  return nullptr;
211193640Sariff}
212193640Sariff
213193640Sariffstatic std::string GetModuleName(uintptr_t PC) {
214193640Sariff  char ModulePathRaw[4096] = "";  // What's PATH_MAX in portable C++?
215193640Sariff  void *OffsetRaw = nullptr;
216193640Sariff  if (!EF->__sanitizer_get_module_and_offset_for_pc(
217193640Sariff      reinterpret_cast<void *>(PC), ModulePathRaw,
218193640Sariff      sizeof(ModulePathRaw), &OffsetRaw))
219193640Sariff    return "";
220193640Sariff  return ModulePathRaw;
221193640Sariff}
222193640Sariff
223193640Sarifftemplate<class CallBack>
224193640Sariffvoid TracePC::IterateCoveredFunctions(CallBack CB) {
225193640Sariff  for (size_t i = 0; i < NumPCTables; i++) {
226    auto &M = ModulePCTable[i];
227    assert(M.Start < M.Stop);
228    auto ModuleName = GetModuleName(M.Start->PC);
229    for (auto NextFE = M.Start; NextFE < M.Stop; ) {
230      auto FE = NextFE;
231      assert(PcIsFuncEntry(FE) && "Not a function entry point");
232      do {
233        NextFE++;
234      } while (NextFE < M.Stop && !(PcIsFuncEntry(NextFE)));
235      CB(FE, NextFE, ObservedFuncs[FE->PC]);
236    }
237  }
238}
239
240void TracePC::SetFocusFunction(const std::string &FuncName) {
241  // This function should be called once.
242  assert(!FocusFunctionCounterPtr);
243  if (FuncName.empty())
244    return;
245  for (size_t M = 0; M < NumModules; M++) {
246    auto &PCTE = ModulePCTable[M];
247    size_t N = PCTE.Stop - PCTE.Start;
248    for (size_t I = 0; I < N; I++) {
249      if (!(PcIsFuncEntry(&PCTE.Start[I]))) continue;  // not a function entry.
250      auto Name = DescribePC("%F", GetNextInstructionPc(PCTE.Start[I].PC));
251      if (Name[0] == 'i' && Name[1] == 'n' && Name[2] == ' ')
252        Name = Name.substr(3, std::string::npos);
253      if (FuncName != Name) continue;
254      Printf("INFO: Focus function is set to '%s'\n", Name.c_str());
255      FocusFunctionCounterPtr = Modules[M].Start() + I;
256      return;
257    }
258  }
259}
260
261bool TracePC::ObservedFocusFunction() {
262  return FocusFunctionCounterPtr && *FocusFunctionCounterPtr;
263}
264
265void TracePC::PrintCoverage() {
266  if (!EF->__sanitizer_symbolize_pc ||
267      !EF->__sanitizer_get_module_and_offset_for_pc) {
268    Printf("INFO: __sanitizer_symbolize_pc or "
269           "__sanitizer_get_module_and_offset_for_pc is not available,"
270           " not printing coverage\n");
271    return;
272  }
273  Printf("COVERAGE:\n");
274  auto CoveredFunctionCallback = [&](const PCTableEntry *First,
275                                     const PCTableEntry *Last,
276                                     uintptr_t Counter) {
277    assert(First < Last);
278    auto VisualizePC = GetNextInstructionPc(First->PC);
279    std::string FileStr = DescribePC("%s", VisualizePC);
280    if (!IsInterestingCoverageFile(FileStr))
281      return;
282    std::string FunctionStr = DescribePC("%F", VisualizePC);
283    if (FunctionStr.find("in ") == 0)
284      FunctionStr = FunctionStr.substr(3);
285    std::string LineStr = DescribePC("%l", VisualizePC);
286    size_t NumEdges = Last - First;
287    Vector<uintptr_t> UncoveredPCs;
288    for (auto TE = First; TE < Last; TE++)
289      if (!ObservedPCs.count(TE))
290        UncoveredPCs.push_back(TE->PC);
291    Printf("%sCOVERED_FUNC: hits: %zd", Counter ? "" : "UN", Counter);
292    Printf(" edges: %zd/%zd", NumEdges - UncoveredPCs.size(), NumEdges);
293    Printf(" %s %s:%s\n", FunctionStr.c_str(), FileStr.c_str(),
294           LineStr.c_str());
295    if (Counter)
296      for (auto PC : UncoveredPCs)
297        Printf("  UNCOVERED_PC: %s\n",
298               DescribePC("%s:%l", GetNextInstructionPc(PC)).c_str());
299  };
300
301  IterateCoveredFunctions(CoveredFunctionCallback);
302}
303
304// Value profile.
305// We keep track of various values that affect control flow.
306// These values are inserted into a bit-set-based hash map.
307// Every new bit in the map is treated as a new coverage.
308//
309// For memcmp/strcmp/etc the interesting value is the length of the common
310// prefix of the parameters.
311// For cmp instructions the interesting value is a XOR of the parameters.
312// The interesting value is mixed up with the PC and is then added to the map.
313
314ATTRIBUTE_NO_SANITIZE_ALL
315void TracePC::AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2,
316                                size_t n, bool StopAtZero) {
317  if (!n) return;
318  size_t Len = std::min(n, Word::GetMaxSize());
319  const uint8_t *A1 = reinterpret_cast<const uint8_t *>(s1);
320  const uint8_t *A2 = reinterpret_cast<const uint8_t *>(s2);
321  uint8_t B1[Word::kMaxSize];
322  uint8_t B2[Word::kMaxSize];
323  // Copy the data into locals in this non-msan-instrumented function
324  // to avoid msan complaining further.
325  size_t Hash = 0;  // Compute some simple hash of both strings.
326  for (size_t i = 0; i < Len; i++) {
327    B1[i] = A1[i];
328    B2[i] = A2[i];
329    size_t T = B1[i];
330    Hash ^= (T << 8) | B2[i];
331  }
332  size_t I = 0;
333  uint8_t HammingDistance = 0;
334  for (; I < Len; I++) {
335    if (B1[I] != B2[I] || (StopAtZero && B1[I] == 0)) {
336      HammingDistance = Popcountll(B1[I] ^ B2[I]);
337      break;
338    }
339  }
340  size_t PC = reinterpret_cast<size_t>(caller_pc);
341  size_t Idx = (PC & 4095) | (I << 12);
342  Idx += HammingDistance;
343  ValueProfileMap.AddValue(Idx);
344  TORCW.Insert(Idx ^ Hash, Word(B1, Len), Word(B2, Len));
345}
346
347template <class T>
348ATTRIBUTE_TARGET_POPCNT ALWAYS_INLINE
349ATTRIBUTE_NO_SANITIZE_ALL
350void TracePC::HandleCmp(uintptr_t PC, T Arg1, T Arg2) {
351  uint64_t ArgXor = Arg1 ^ Arg2;
352  if (sizeof(T) == 4)
353      TORC4.Insert(ArgXor, Arg1, Arg2);
354  else if (sizeof(T) == 8)
355      TORC8.Insert(ArgXor, Arg1, Arg2);
356  uint64_t HammingDistance = Popcountll(ArgXor);  // [0,64]
357  uint64_t AbsoluteDistance = (Arg1 == Arg2 ? 0 : Clzll(Arg1 - Arg2) + 1);
358  ValueProfileMap.AddValue(PC * 128 + HammingDistance);
359  ValueProfileMap.AddValue(PC * 128 + 64 + AbsoluteDistance);
360}
361
362static size_t InternalStrnlen(const char *S, size_t MaxLen) {
363  size_t Len = 0;
364  for (; Len < MaxLen && S[Len]; Len++) {}
365  return Len;
366}
367
368// Finds min of (strlen(S1), strlen(S2)).
369// Needed bacause one of these strings may actually be non-zero terminated.
370static size_t InternalStrnlen2(const char *S1, const char *S2) {
371  size_t Len = 0;
372  for (; S1[Len] && S2[Len]; Len++)  {}
373  return Len;
374}
375
376void TracePC::ClearInlineCounters() {
377  IterateCounterRegions([](const Module::Region &R){
378    if (R.Enabled)
379      memset(R.Start, 0, R.Stop - R.Start);
380  });
381}
382
383ATTRIBUTE_NO_SANITIZE_ALL
384void TracePC::RecordInitialStack() {
385  int stack;
386  __sancov_lowest_stack = InitialStack = reinterpret_cast<uintptr_t>(&stack);
387}
388
389uintptr_t TracePC::GetMaxStackOffset() const {
390  return InitialStack - __sancov_lowest_stack;  // Stack grows down
391}
392
393void WarnAboutDeprecatedInstrumentation(const char *flag) {
394  // Use RawPrint because Printf cannot be used on Windows before OutputFile is
395  // initialized.
396  RawPrint(flag);
397  RawPrint(
398      " is no longer supported by libFuzzer.\n"
399      "Please either migrate to a compiler that supports -fsanitize=fuzzer\n"
400      "or use an older version of libFuzzer\n");
401  exit(1);
402}
403
404} // namespace fuzzer
405
406extern "C" {
407ATTRIBUTE_INTERFACE
408ATTRIBUTE_NO_SANITIZE_ALL
409void __sanitizer_cov_trace_pc_guard(uint32_t *Guard) {
410  fuzzer::WarnAboutDeprecatedInstrumentation(
411      "-fsanitize-coverage=trace-pc-guard");
412}
413
414// Best-effort support for -fsanitize-coverage=trace-pc, which is available
415// in both Clang and GCC.
416ATTRIBUTE_INTERFACE
417ATTRIBUTE_NO_SANITIZE_ALL
418void __sanitizer_cov_trace_pc() {
419  fuzzer::WarnAboutDeprecatedInstrumentation("-fsanitize-coverage=trace-pc");
420}
421
422ATTRIBUTE_INTERFACE
423void __sanitizer_cov_trace_pc_guard_init(uint32_t *Start, uint32_t *Stop) {
424  fuzzer::WarnAboutDeprecatedInstrumentation(
425      "-fsanitize-coverage=trace-pc-guard");
426}
427
428ATTRIBUTE_INTERFACE
429void __sanitizer_cov_8bit_counters_init(uint8_t *Start, uint8_t *Stop) {
430  fuzzer::TPC.HandleInline8bitCountersInit(Start, Stop);
431}
432
433ATTRIBUTE_INTERFACE
434void __sanitizer_cov_pcs_init(const uintptr_t *pcs_beg,
435                              const uintptr_t *pcs_end) {
436  fuzzer::TPC.HandlePCsInit(pcs_beg, pcs_end);
437}
438
439ATTRIBUTE_INTERFACE
440ATTRIBUTE_NO_SANITIZE_ALL
441void __sanitizer_cov_trace_pc_indir(uintptr_t Callee) {
442  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
443  fuzzer::TPC.HandleCallerCallee(PC, Callee);
444}
445
446ATTRIBUTE_INTERFACE
447ATTRIBUTE_NO_SANITIZE_ALL
448ATTRIBUTE_TARGET_POPCNT
449void __sanitizer_cov_trace_cmp8(uint64_t Arg1, uint64_t Arg2) {
450  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
451  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
452}
453
454ATTRIBUTE_INTERFACE
455ATTRIBUTE_NO_SANITIZE_ALL
456ATTRIBUTE_TARGET_POPCNT
457// Now the __sanitizer_cov_trace_const_cmp[1248] callbacks just mimic
458// the behaviour of __sanitizer_cov_trace_cmp[1248] ones. This, however,
459// should be changed later to make full use of instrumentation.
460void __sanitizer_cov_trace_const_cmp8(uint64_t Arg1, uint64_t Arg2) {
461  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
462  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
463}
464
465ATTRIBUTE_INTERFACE
466ATTRIBUTE_NO_SANITIZE_ALL
467ATTRIBUTE_TARGET_POPCNT
468void __sanitizer_cov_trace_cmp4(uint32_t Arg1, uint32_t Arg2) {
469  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
470  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
471}
472
473ATTRIBUTE_INTERFACE
474ATTRIBUTE_NO_SANITIZE_ALL
475ATTRIBUTE_TARGET_POPCNT
476void __sanitizer_cov_trace_const_cmp4(uint32_t Arg1, uint32_t Arg2) {
477  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
478  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
479}
480
481ATTRIBUTE_INTERFACE
482ATTRIBUTE_NO_SANITIZE_ALL
483ATTRIBUTE_TARGET_POPCNT
484void __sanitizer_cov_trace_cmp2(uint16_t Arg1, uint16_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
492void __sanitizer_cov_trace_const_cmp2(uint16_t Arg1, uint16_t Arg2) {
493  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
494  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
495}
496
497ATTRIBUTE_INTERFACE
498ATTRIBUTE_NO_SANITIZE_ALL
499ATTRIBUTE_TARGET_POPCNT
500void __sanitizer_cov_trace_cmp1(uint8_t Arg1, uint8_t Arg2) {
501  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
502  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
503}
504
505ATTRIBUTE_INTERFACE
506ATTRIBUTE_NO_SANITIZE_ALL
507ATTRIBUTE_TARGET_POPCNT
508void __sanitizer_cov_trace_const_cmp1(uint8_t Arg1, uint8_t Arg2) {
509  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
510  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
511}
512
513ATTRIBUTE_INTERFACE
514ATTRIBUTE_NO_SANITIZE_ALL
515ATTRIBUTE_TARGET_POPCNT
516void __sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases) {
517  uint64_t N = Cases[0];
518  uint64_t ValSizeInBits = Cases[1];
519  uint64_t *Vals = Cases + 2;
520  // Skip the most common and the most boring case: all switch values are small.
521  // We may want to skip this at compile-time, but it will make the
522  // instrumentation less general.
523  if (Vals[N - 1]  < 256)
524    return;
525  // Also skip small inputs values, they won't give good signal.
526  if (Val < 256)
527    return;
528  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
529  size_t i;
530  uint64_t Smaller = 0;
531  uint64_t Larger = ~(uint64_t)0;
532  // Find two switch values such that Smaller < Val < Larger.
533  // Use 0 and 0xfff..f as the defaults.
534  for (i = 0; i < N; i++) {
535    if (Val < Vals[i]) {
536      Larger = Vals[i];
537      break;
538    }
539    if (Val > Vals[i]) Smaller = Vals[i];
540  }
541
542  // Apply HandleCmp to {Val,Smaller} and {Val, Larger},
543  // use i as the PC modifier for HandleCmp.
544  if (ValSizeInBits == 16) {
545    fuzzer::TPC.HandleCmp(PC + 2 * i, static_cast<uint16_t>(Val),
546                          (uint16_t)(Smaller));
547    fuzzer::TPC.HandleCmp(PC + 2 * i + 1, static_cast<uint16_t>(Val),
548                          (uint16_t)(Larger));
549  } else if (ValSizeInBits == 32) {
550    fuzzer::TPC.HandleCmp(PC + 2 * i, static_cast<uint32_t>(Val),
551                          (uint32_t)(Smaller));
552    fuzzer::TPC.HandleCmp(PC + 2 * i + 1, static_cast<uint32_t>(Val),
553                          (uint32_t)(Larger));
554  } else {
555    fuzzer::TPC.HandleCmp(PC + 2*i, Val, Smaller);
556    fuzzer::TPC.HandleCmp(PC + 2*i + 1, Val, Larger);
557  }
558}
559
560ATTRIBUTE_INTERFACE
561ATTRIBUTE_NO_SANITIZE_ALL
562ATTRIBUTE_TARGET_POPCNT
563void __sanitizer_cov_trace_div4(uint32_t Val) {
564  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
565  fuzzer::TPC.HandleCmp(PC, Val, (uint32_t)0);
566}
567
568ATTRIBUTE_INTERFACE
569ATTRIBUTE_NO_SANITIZE_ALL
570ATTRIBUTE_TARGET_POPCNT
571void __sanitizer_cov_trace_div8(uint64_t Val) {
572  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
573  fuzzer::TPC.HandleCmp(PC, Val, (uint64_t)0);
574}
575
576ATTRIBUTE_INTERFACE
577ATTRIBUTE_NO_SANITIZE_ALL
578ATTRIBUTE_TARGET_POPCNT
579void __sanitizer_cov_trace_gep(uintptr_t Idx) {
580  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
581  fuzzer::TPC.HandleCmp(PC, Idx, (uintptr_t)0);
582}
583
584ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
585void __sanitizer_weak_hook_memcmp(void *caller_pc, const void *s1,
586                                  const void *s2, size_t n, int result) {
587  if (!fuzzer::RunningUserCallback) return;
588  if (result == 0) return;  // No reason to mutate.
589  if (n <= 1) return;  // Not interesting.
590  fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n, /*StopAtZero*/false);
591}
592
593ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
594void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1,
595                                   const char *s2, size_t n, int result) {
596  if (!fuzzer::RunningUserCallback) return;
597  if (result == 0) return;  // No reason to mutate.
598  size_t Len1 = fuzzer::InternalStrnlen(s1, n);
599  size_t Len2 = fuzzer::InternalStrnlen(s2, n);
600  n = std::min(n, Len1);
601  n = std::min(n, Len2);
602  if (n <= 1) return;  // Not interesting.
603  fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n, /*StopAtZero*/true);
604}
605
606ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
607void __sanitizer_weak_hook_strcmp(void *caller_pc, const char *s1,
608                                   const char *s2, int result) {
609  if (!fuzzer::RunningUserCallback) return;
610  if (result == 0) return;  // No reason to mutate.
611  size_t N = fuzzer::InternalStrnlen2(s1, s2);
612  if (N <= 1) return;  // Not interesting.
613  fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, N, /*StopAtZero*/true);
614}
615
616ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
617void __sanitizer_weak_hook_strncasecmp(void *called_pc, const char *s1,
618                                       const char *s2, size_t n, int result) {
619  if (!fuzzer::RunningUserCallback) return;
620  return __sanitizer_weak_hook_strncmp(called_pc, s1, s2, n, result);
621}
622
623ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
624void __sanitizer_weak_hook_strcasecmp(void *called_pc, const char *s1,
625                                      const char *s2, int result) {
626  if (!fuzzer::RunningUserCallback) return;
627  return __sanitizer_weak_hook_strcmp(called_pc, s1, s2, result);
628}
629
630ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
631void __sanitizer_weak_hook_strstr(void *called_pc, const char *s1,
632                                  const char *s2, char *result) {
633  if (!fuzzer::RunningUserCallback) return;
634  fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), strlen(s2));
635}
636
637ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
638void __sanitizer_weak_hook_strcasestr(void *called_pc, const char *s1,
639                                      const char *s2, char *result) {
640  if (!fuzzer::RunningUserCallback) return;
641  fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), strlen(s2));
642}
643
644ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
645void __sanitizer_weak_hook_memmem(void *called_pc, const void *s1, size_t len1,
646                                  const void *s2, size_t len2, void *result) {
647  if (!fuzzer::RunningUserCallback) return;
648  fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), len2);
649}
650}  // extern "C"
651