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 "FuzzerUtil.h"
23 #include "FuzzerValueBitMap.h"
24 #include <set>
25
26 // Used by -fsanitize-coverage=stack-depth to track stack depth
27 ATTRIBUTES_INTERFACE_TLS_INITIAL_EXEC uintptr_t __sancov_lowest_stack;
28
29 namespace fuzzer {
30
31 TracePC TPC;
32
GetTotalPCCoverage()33 size_t TracePC::GetTotalPCCoverage() {
34 return ObservedPCs.size();
35 }
36
37
HandleInline8bitCountersInit(uint8_t * Start,uint8_t * Stop)38 void TracePC::HandleInline8bitCountersInit(uint8_t *Start, uint8_t *Stop) {
39 if (Start == Stop) return;
40 if (NumModules &&
41 Modules[NumModules - 1].Start() == Start)
42 return;
43 assert(NumModules <
44 sizeof(Modules) / sizeof(Modules[0]));
45 auto &M = Modules[NumModules++];
46 uint8_t *AlignedStart = RoundUpByPage(Start);
47 uint8_t *AlignedStop = RoundDownByPage(Stop);
48 size_t NumFullPages = AlignedStop > AlignedStart ?
49 (AlignedStop - AlignedStart) / PageSize() : 0;
50 bool NeedFirst = Start < AlignedStart || !NumFullPages;
51 bool NeedLast = Stop > AlignedStop && AlignedStop >= AlignedStart;
52 M.NumRegions = NumFullPages + NeedFirst + NeedLast;;
53 assert(M.NumRegions > 0);
54 M.Regions = new Module::Region[M.NumRegions];
55 assert(M.Regions);
56 size_t R = 0;
57 if (NeedFirst)
58 M.Regions[R++] = {Start, std::min(Stop, AlignedStart), true, false};
59 for (uint8_t *P = AlignedStart; P < AlignedStop; P += PageSize())
60 M.Regions[R++] = {P, P + PageSize(), true, true};
61 if (NeedLast)
62 M.Regions[R++] = {AlignedStop, Stop, true, false};
63 assert(R == M.NumRegions);
64 assert(M.Size() == (size_t)(Stop - Start));
65 assert(M.Stop() == Stop);
66 assert(M.Start() == Start);
67 NumInline8bitCounters += M.Size();
68 }
69
HandlePCsInit(const uintptr_t * Start,const uintptr_t * Stop)70 void TracePC::HandlePCsInit(const uintptr_t *Start, const uintptr_t *Stop) {
71 const PCTableEntry *B = reinterpret_cast<const PCTableEntry *>(Start);
72 const PCTableEntry *E = reinterpret_cast<const PCTableEntry *>(Stop);
73 if (NumPCTables && ModulePCTable[NumPCTables - 1].Start == B) return;
74 assert(NumPCTables < sizeof(ModulePCTable) / sizeof(ModulePCTable[0]));
75 ModulePCTable[NumPCTables++] = {B, E};
76 NumPCsInPCTables += E - B;
77 }
78
PrintModuleInfo()79 void TracePC::PrintModuleInfo() {
80 if (NumModules) {
81 Printf("INFO: Loaded %zd modules (%zd inline 8-bit counters): ",
82 NumModules, NumInline8bitCounters);
83 for (size_t i = 0; i < NumModules; i++)
84 Printf("%zd [%p, %p), ", Modules[i].Size(), Modules[i].Start(),
85 Modules[i].Stop());
86 Printf("\n");
87 }
88 if (NumPCTables) {
89 Printf("INFO: Loaded %zd PC tables (%zd PCs): ", NumPCTables,
90 NumPCsInPCTables);
91 for (size_t i = 0; i < NumPCTables; i++) {
92 Printf("%zd [%p,%p), ", ModulePCTable[i].Stop - ModulePCTable[i].Start,
93 ModulePCTable[i].Start, ModulePCTable[i].Stop);
94 }
95 Printf("\n");
96
97 if (NumInline8bitCounters && NumInline8bitCounters != NumPCsInPCTables) {
98 Printf("ERROR: The size of coverage PC tables does not match the\n"
99 "number of instrumented PCs. This might be a compiler bug,\n"
100 "please contact the libFuzzer developers.\n"
101 "Also check https://bugs.llvm.org/show_bug.cgi?id=34636\n"
102 "for possible workarounds (tl;dr: don't use the old GNU ld)\n");
103 _Exit(1);
104 }
105 }
106 if (size_t NumExtraCounters = ExtraCountersEnd() - ExtraCountersBegin())
107 Printf("INFO: %zd Extra Counters\n", NumExtraCounters);
108 }
109
110 ATTRIBUTE_NO_SANITIZE_ALL
HandleCallerCallee(uintptr_t Caller,uintptr_t Callee)111 void TracePC::HandleCallerCallee(uintptr_t Caller, uintptr_t Callee) {
112 const uintptr_t kBits = 12;
113 const uintptr_t kMask = (1 << kBits) - 1;
114 uintptr_t Idx = (Caller & kMask) | ((Callee & kMask) << kBits);
115 ValueProfileMap.AddValueModPrime(Idx);
116 }
117
118 /// \return the address of the previous instruction.
119 /// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.h`
GetPreviousInstructionPc(uintptr_t PC)120 inline ALWAYS_INLINE uintptr_t GetPreviousInstructionPc(uintptr_t PC) {
121 #if defined(__arm__)
122 // T32 (Thumb) branch instructions might be 16 or 32 bit long,
123 // so we return (pc-2) in that case in order to be safe.
124 // For A32 mode we return (pc-4) because all instructions are 32 bit long.
125 return (PC - 3) & (~1);
126 #elif defined(__powerpc__) || defined(__powerpc64__) || defined(__aarch64__)
127 // PCs are always 4 byte aligned.
128 return PC - 4;
129 #elif defined(__sparc__) || defined(__mips__)
130 return PC - 8;
131 #else
132 return PC - 1;
133 #endif
134 }
135
136 /// \return the address of the next instruction.
137 /// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.cpp`
GetNextInstructionPc(uintptr_t PC)138 ALWAYS_INLINE uintptr_t TracePC::GetNextInstructionPc(uintptr_t PC) {
139 #if defined(__mips__)
140 return PC + 8;
141 #elif defined(__powerpc__) || defined(__sparc__) || defined(__arm__) || \
142 defined(__aarch64__)
143 return PC + 4;
144 #else
145 return PC + 1;
146 #endif
147 }
148
UpdateObservedPCs()149 void TracePC::UpdateObservedPCs() {
150 Vector<uintptr_t> CoveredFuncs;
151 auto ObservePC = [&](const PCTableEntry *TE) {
152 if (ObservedPCs.insert(TE).second && DoPrintNewPCs) {
153 PrintPC("\tNEW_PC: %p %F %L", "\tNEW_PC: %p",
154 GetNextInstructionPc(TE->PC));
155 Printf("\n");
156 }
157 };
158
159 auto Observe = [&](const PCTableEntry *TE) {
160 if (PcIsFuncEntry(TE))
161 if (++ObservedFuncs[TE->PC] == 1 && NumPrintNewFuncs)
162 CoveredFuncs.push_back(TE->PC);
163 ObservePC(TE);
164 };
165
166 if (NumPCsInPCTables) {
167 if (NumInline8bitCounters == NumPCsInPCTables) {
168 for (size_t i = 0; i < NumModules; i++) {
169 auto &M = Modules[i];
170 assert(M.Size() ==
171 (size_t)(ModulePCTable[i].Stop - ModulePCTable[i].Start));
172 for (size_t r = 0; r < M.NumRegions; r++) {
173 auto &R = M.Regions[r];
174 if (!R.Enabled) continue;
175 for (uint8_t *P = R.Start; P < R.Stop; P++)
176 if (*P)
177 Observe(&ModulePCTable[i].Start[M.Idx(P)]);
178 }
179 }
180 }
181 }
182
183 for (size_t i = 0, N = Min(CoveredFuncs.size(), NumPrintNewFuncs); i < N;
184 i++) {
185 Printf("\tNEW_FUNC[%zd/%zd]: ", i + 1, CoveredFuncs.size());
186 PrintPC("%p %F %L", "%p", GetNextInstructionPc(CoveredFuncs[i]));
187 Printf("\n");
188 }
189 }
190
PCTableEntryIdx(const PCTableEntry * TE)191 uintptr_t TracePC::PCTableEntryIdx(const PCTableEntry *TE) {
192 size_t TotalTEs = 0;
193 for (size_t i = 0; i < NumPCTables; i++) {
194 auto &M = ModulePCTable[i];
195 if (TE >= M.Start && TE < M.Stop)
196 return TotalTEs + TE - M.Start;
197 TotalTEs += M.Stop - M.Start;
198 }
199 assert(0);
200 return 0;
201 }
202
PCTableEntryByIdx(uintptr_t Idx)203 const TracePC::PCTableEntry *TracePC::PCTableEntryByIdx(uintptr_t Idx) {
204 for (size_t i = 0; i < NumPCTables; i++) {
205 auto &M = ModulePCTable[i];
206 size_t Size = M.Stop - M.Start;
207 if (Idx < Size) return &M.Start[Idx];
208 Idx -= Size;
209 }
210 return nullptr;
211 }
212
GetModuleName(uintptr_t PC)213 static std::string GetModuleName(uintptr_t PC) {
214 char ModulePathRaw[4096] = ""; // What's PATH_MAX in portable C++?
215 void *OffsetRaw = nullptr;
216 if (!EF->__sanitizer_get_module_and_offset_for_pc(
217 reinterpret_cast<void *>(PC), ModulePathRaw,
218 sizeof(ModulePathRaw), &OffsetRaw))
219 return "";
220 return ModulePathRaw;
221 }
222
223 template<class CallBack>
IterateCoveredFunctions(CallBack CB)224 void TracePC::IterateCoveredFunctions(CallBack CB) {
225 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
SetFocusFunction(const std::string & FuncName)240 void 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
ObservedFocusFunction()261 bool TracePC::ObservedFocusFunction() {
262 return FocusFunctionCounterPtr && *FocusFunctionCounterPtr;
263 }
264
PrintCoverage()265 void 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
314 ATTRIBUTE_NO_SANITIZE_ALL
AddValueForMemcmp(void * caller_pc,const void * s1,const void * s2,size_t n,bool StopAtZero)315 void 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
347 template <class T>
348 ATTRIBUTE_TARGET_POPCNT ALWAYS_INLINE
349 ATTRIBUTE_NO_SANITIZE_ALL
HandleCmp(uintptr_t PC,T Arg1,T Arg2)350 void 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
InternalStrnlen(const char * S,size_t MaxLen)362 static 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.
InternalStrnlen2(const char * S1,const char * S2)370 static 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
ClearInlineCounters()376 void TracePC::ClearInlineCounters() {
377 IterateCounterRegions([](const Module::Region &R){
378 if (R.Enabled)
379 memset(R.Start, 0, R.Stop - R.Start);
380 });
381 }
382
383 ATTRIBUTE_NO_SANITIZE_ALL
RecordInitialStack()384 void TracePC::RecordInitialStack() {
385 int stack;
386 __sancov_lowest_stack = InitialStack = reinterpret_cast<uintptr_t>(&stack);
387 }
388
GetMaxStackOffset() const389 uintptr_t TracePC::GetMaxStackOffset() const {
390 return InitialStack - __sancov_lowest_stack; // Stack grows down
391 }
392
WarnAboutDeprecatedInstrumentation(const char * flag)393 void 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
406 extern "C" {
407 ATTRIBUTE_INTERFACE
408 ATTRIBUTE_NO_SANITIZE_ALL
__sanitizer_cov_trace_pc_guard(uint32_t * Guard)409 void __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.
416 ATTRIBUTE_INTERFACE
417 ATTRIBUTE_NO_SANITIZE_ALL
__sanitizer_cov_trace_pc()418 void __sanitizer_cov_trace_pc() {
419 fuzzer::WarnAboutDeprecatedInstrumentation("-fsanitize-coverage=trace-pc");
420 }
421
422 ATTRIBUTE_INTERFACE
__sanitizer_cov_trace_pc_guard_init(uint32_t * Start,uint32_t * Stop)423 void __sanitizer_cov_trace_pc_guard_init(uint32_t *Start, uint32_t *Stop) {
424 fuzzer::WarnAboutDeprecatedInstrumentation(
425 "-fsanitize-coverage=trace-pc-guard");
426 }
427
428 ATTRIBUTE_INTERFACE
__sanitizer_cov_8bit_counters_init(uint8_t * Start,uint8_t * Stop)429 void __sanitizer_cov_8bit_counters_init(uint8_t *Start, uint8_t *Stop) {
430 fuzzer::TPC.HandleInline8bitCountersInit(Start, Stop);
431 }
432
433 ATTRIBUTE_INTERFACE
__sanitizer_cov_pcs_init(const uintptr_t * pcs_beg,const uintptr_t * pcs_end)434 void __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
439 ATTRIBUTE_INTERFACE
440 ATTRIBUTE_NO_SANITIZE_ALL
__sanitizer_cov_trace_pc_indir(uintptr_t Callee)441 void __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
446 ATTRIBUTE_INTERFACE
447 ATTRIBUTE_NO_SANITIZE_ALL
448 ATTRIBUTE_TARGET_POPCNT
__sanitizer_cov_trace_cmp8(uint64_t Arg1,uint64_t Arg2)449 void __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
454 ATTRIBUTE_INTERFACE
455 ATTRIBUTE_NO_SANITIZE_ALL
456 ATTRIBUTE_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.
__sanitizer_cov_trace_const_cmp8(uint64_t Arg1,uint64_t Arg2)460 void __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
465 ATTRIBUTE_INTERFACE
466 ATTRIBUTE_NO_SANITIZE_ALL
467 ATTRIBUTE_TARGET_POPCNT
__sanitizer_cov_trace_cmp4(uint32_t Arg1,uint32_t Arg2)468 void __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
473 ATTRIBUTE_INTERFACE
474 ATTRIBUTE_NO_SANITIZE_ALL
475 ATTRIBUTE_TARGET_POPCNT
__sanitizer_cov_trace_const_cmp4(uint32_t Arg1,uint32_t Arg2)476 void __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
481 ATTRIBUTE_INTERFACE
482 ATTRIBUTE_NO_SANITIZE_ALL
483 ATTRIBUTE_TARGET_POPCNT
__sanitizer_cov_trace_cmp2(uint16_t Arg1,uint16_t Arg2)484 void __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
489 ATTRIBUTE_INTERFACE
490 ATTRIBUTE_NO_SANITIZE_ALL
491 ATTRIBUTE_TARGET_POPCNT
__sanitizer_cov_trace_const_cmp2(uint16_t Arg1,uint16_t Arg2)492 void __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
497 ATTRIBUTE_INTERFACE
498 ATTRIBUTE_NO_SANITIZE_ALL
499 ATTRIBUTE_TARGET_POPCNT
__sanitizer_cov_trace_cmp1(uint8_t Arg1,uint8_t Arg2)500 void __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
505 ATTRIBUTE_INTERFACE
506 ATTRIBUTE_NO_SANITIZE_ALL
507 ATTRIBUTE_TARGET_POPCNT
__sanitizer_cov_trace_const_cmp1(uint8_t Arg1,uint8_t Arg2)508 void __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
513 ATTRIBUTE_INTERFACE
514 ATTRIBUTE_NO_SANITIZE_ALL
515 ATTRIBUTE_TARGET_POPCNT
__sanitizer_cov_trace_switch(uint64_t Val,uint64_t * Cases)516 void __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
560 ATTRIBUTE_INTERFACE
561 ATTRIBUTE_NO_SANITIZE_ALL
562 ATTRIBUTE_TARGET_POPCNT
__sanitizer_cov_trace_div4(uint32_t Val)563 void __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
568 ATTRIBUTE_INTERFACE
569 ATTRIBUTE_NO_SANITIZE_ALL
570 ATTRIBUTE_TARGET_POPCNT
__sanitizer_cov_trace_div8(uint64_t Val)571 void __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
576 ATTRIBUTE_INTERFACE
577 ATTRIBUTE_NO_SANITIZE_ALL
578 ATTRIBUTE_TARGET_POPCNT
__sanitizer_cov_trace_gep(uintptr_t Idx)579 void __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
584 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
__sanitizer_weak_hook_memcmp(void * caller_pc,const void * s1,const void * s2,size_t n,int result)585 void __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
593 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
__sanitizer_weak_hook_strncmp(void * caller_pc,const char * s1,const char * s2,size_t n,int result)594 void __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
606 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
__sanitizer_weak_hook_strcmp(void * caller_pc,const char * s1,const char * s2,int result)607 void __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
616 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
__sanitizer_weak_hook_strncasecmp(void * called_pc,const char * s1,const char * s2,size_t n,int result)617 void __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
623 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
__sanitizer_weak_hook_strcasecmp(void * called_pc,const char * s1,const char * s2,int result)624 void __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
630 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
__sanitizer_weak_hook_strstr(void * called_pc,const char * s1,const char * s2,char * result)631 void __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
637 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
__sanitizer_weak_hook_strcasestr(void * called_pc,const char * s1,const char * s2,char * result)638 void __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
644 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
__sanitizer_weak_hook_memmem(void * called_pc,const void * s1,size_t len1,const void * s2,size_t len2,void * result)645 void __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