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(P: Start);
48 uint8_t *AlignedStop = RoundDownByPage(P: 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: Start, .Stop: std::min(a: Stop, b: AlignedStart), .Enabled: true, .OneFullPage: false};
60 for (uint8_t *P = AlignedStart; P < AlignedStop; P += PageSize())
61 M.Regions[R++] = {.Start: P, .Stop: P + PageSize(), .Enabled: true, .OneFullPage: true};
62 if (NeedLast)
63 M.Regions[R++] = {.Start: AlignedStop, .Stop: Stop, .Enabled: true, .OneFullPage: 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 if (Start == Stop) {
73 return;
74 }
75 const PCTableEntry *B = reinterpret_cast<const PCTableEntry *>(Start);
76 const PCTableEntry *E = reinterpret_cast<const PCTableEntry *>(Stop);
77 if (NumPCTables && ModulePCTable[NumPCTables - 1].Start == B) return;
78 assert(NumPCTables < sizeof(ModulePCTable) / sizeof(ModulePCTable[0]));
79 ModulePCTable[NumPCTables++] = {.Start: B, .Stop: E};
80 NumPCsInPCTables += E - B;
81}
82
83void TracePC::PrintModuleInfo() {
84 if (NumModules) {
85 Printf(Fmt: "INFO: Loaded %zd modules (%zd inline 8-bit counters): ",
86 NumModules, NumInline8bitCounters);
87 for (size_t i = 0; i < NumModules; i++)
88 Printf(Fmt: "%zd [%p, %p), ", Modules[i].Size(), Modules[i].Start(),
89 Modules[i].Stop());
90 Printf(Fmt: "\n");
91 }
92 if (NumPCTables) {
93 Printf(Fmt: "INFO: Loaded %zd PC tables (%zd PCs): ", NumPCTables,
94 NumPCsInPCTables);
95 for (size_t i = 0; i < NumPCTables; i++) {
96 Printf(Fmt: "%zd [%p,%p), ", ModulePCTable[i].Stop - ModulePCTable[i].Start,
97 ModulePCTable[i].Start, ModulePCTable[i].Stop);
98 }
99 Printf(Fmt: "\n");
100
101 if (NumInline8bitCounters && NumInline8bitCounters != NumPCsInPCTables) {
102 Printf(Fmt: "ERROR: The size of coverage PC tables does not match the\n"
103 "number of instrumented PCs. This might be a compiler bug,\n"
104 "please contact the libFuzzer developers.\n"
105 "Also check https://bugs.llvm.org/show_bug.cgi?id=34636\n"
106 "for possible workarounds (tl;dr: don't use the old GNU ld)\n");
107 _Exit(status: 1);
108 }
109 }
110 if (size_t NumExtraCounters = ExtraCountersEnd() - ExtraCountersBegin())
111 Printf(Fmt: "INFO: %zd Extra Counters\n", NumExtraCounters);
112
113 size_t MaxFeatures = CollectFeatures(HandleFeature: [](uint32_t) {});
114 if (MaxFeatures > std::numeric_limits<uint32_t>::max())
115 Printf(Fmt: "WARNING: The coverage PC tables may produce up to %zu features.\n"
116 "This exceeds the maximum 32-bit value. Some features may be\n"
117 "ignored, and fuzzing may become less precise. If possible,\n"
118 "consider refactoring the fuzzer into several smaller fuzzers\n"
119 "linked against only a portion of the current target.\n",
120 MaxFeatures);
121}
122
123ATTRIBUTE_NO_SANITIZE_ALL
124void TracePC::HandleCallerCallee(uintptr_t Caller, uintptr_t Callee) {
125 const uintptr_t kBits = 12;
126 const uintptr_t kMask = (1 << kBits) - 1;
127 uintptr_t Idx = (Caller & kMask) | ((Callee & kMask) << kBits);
128 ValueProfileMap.AddValueModPrime(Value: Idx);
129}
130
131/// \return the address of the previous instruction.
132/// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.h`
133inline ALWAYS_INLINE uintptr_t GetPreviousInstructionPc(uintptr_t PC) {
134#if defined(__arm__)
135 // T32 (Thumb) branch instructions might be 16 or 32 bit long,
136 // so we return (pc-2) in that case in order to be safe.
137 // For A32 mode we return (pc-4) because all instructions are 32 bit long.
138 return (PC - 3) & (~1);
139#elif defined(__sparc__) || defined(__mips__)
140 return PC - 8;
141#elif defined(__riscv__)
142 return PC - 2;
143#elif defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64)
144 return PC - 1;
145#else
146 return PC - 4;
147#endif
148}
149
150/// \return the address of the next instruction.
151/// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.cpp`
152ALWAYS_INLINE uintptr_t TracePC::GetNextInstructionPc(uintptr_t PC) {
153#if defined(__mips__)
154 return PC + 8;
155#elif defined(__powerpc__) || defined(__sparc__) || defined(__arm__) || \
156 defined(__aarch64__) || defined(__loongarch__)
157 return PC + 4;
158#else
159 return PC + 1;
160#endif
161}
162
163void TracePC::UpdateObservedPCs() {
164 std::vector<uintptr_t> CoveredFuncs;
165 auto ObservePC = [&](const PCTableEntry *TE) {
166 if (ObservedPCs.insert(v: TE).second && DoPrintNewPCs) {
167 PrintPC(SymbolizedFMT: "\tNEW_PC: %p %F %L", FallbackFMT: "\tNEW_PC: %p",
168 PC: GetNextInstructionPc(PC: TE->PC));
169 Printf(Fmt: "\n");
170 }
171 };
172
173 auto Observe = [&](const PCTableEntry *TE) {
174 if (PcIsFuncEntry(TE))
175 if (++ObservedFuncs[TE->PC] == 1 && NumPrintNewFuncs)
176 CoveredFuncs.push_back(x: TE->PC);
177 ObservePC(TE);
178 };
179
180 if (NumPCsInPCTables) {
181 if (NumInline8bitCounters == NumPCsInPCTables) {
182 for (size_t i = 0; i < NumModules; i++) {
183 auto &M = Modules[i];
184 assert(M.Size() ==
185 (size_t)(ModulePCTable[i].Stop - ModulePCTable[i].Start));
186 for (size_t r = 0; r < M.NumRegions; r++) {
187 auto &R = M.Regions[r];
188 if (!R.Enabled) continue;
189 for (uint8_t *P = R.Start; P < R.Stop; P++)
190 if (*P)
191 Observe(&ModulePCTable[i].Start[M.Idx(P)]);
192 }
193 }
194 }
195 }
196
197 for (size_t i = 0, N = Min(a: CoveredFuncs.size(), b: NumPrintNewFuncs); i < N;
198 i++) {
199 Printf(Fmt: "\tNEW_FUNC[%zd/%zd]: ", i + 1, CoveredFuncs.size());
200 PrintPC(SymbolizedFMT: "%p %F %L", FallbackFMT: "%p", PC: GetNextInstructionPc(PC: CoveredFuncs[i]));
201 Printf(Fmt: "\n");
202 }
203}
204
205uintptr_t TracePC::PCTableEntryIdx(const PCTableEntry *TE) {
206 size_t TotalTEs = 0;
207 for (size_t i = 0; i < NumPCTables; i++) {
208 auto &M = ModulePCTable[i];
209 if (TE >= M.Start && TE < M.Stop)
210 return TotalTEs + TE - M.Start;
211 TotalTEs += M.Stop - M.Start;
212 }
213 assert(0);
214 return 0;
215}
216
217const TracePC::PCTableEntry *TracePC::PCTableEntryByIdx(uintptr_t Idx) {
218 for (size_t i = 0; i < NumPCTables; i++) {
219 auto &M = ModulePCTable[i];
220 size_t Size = M.Stop - M.Start;
221 if (Idx < Size) return &M.Start[Idx];
222 Idx -= Size;
223 }
224 return nullptr;
225}
226
227static std::string GetModuleName(uintptr_t PC) {
228 char ModulePathRaw[4096] = ""; // What's PATH_MAX in portable C++?
229 void *OffsetRaw = nullptr;
230 if (!EF->__sanitizer_get_module_and_offset_for_pc(
231 reinterpret_cast<void *>(PC), ModulePathRaw,
232 sizeof(ModulePathRaw), &OffsetRaw))
233 return "";
234 return ModulePathRaw;
235}
236
237template<class CallBack>
238void TracePC::IterateCoveredFunctions(CallBack CB) {
239 for (size_t i = 0; i < NumPCTables; i++) {
240 auto &M = ModulePCTable[i];
241 assert(M.Start < M.Stop);
242 auto ModuleName = GetModuleName(PC: M.Start->PC);
243 for (auto NextFE = M.Start; NextFE < M.Stop; ) {
244 auto FE = NextFE;
245 assert(PcIsFuncEntry(FE) && "Not a function entry point");
246 do {
247 NextFE++;
248 } while (NextFE < M.Stop && !(PcIsFuncEntry(TE: NextFE)));
249 CB(FE, NextFE, ObservedFuncs[FE->PC]);
250 }
251 }
252}
253
254void TracePC::SetFocusFunction(const std::string &FuncName) {
255 // This function should be called once.
256 assert(!FocusFunctionCounterPtr);
257 // "auto" is not a valid function name. If this function is called with "auto"
258 // that means the auto focus functionality failed.
259 if (FuncName.empty() || FuncName == "auto")
260 return;
261 for (size_t M = 0; M < NumModules; M++) {
262 auto &PCTE = ModulePCTable[M];
263 size_t N = PCTE.Stop - PCTE.Start;
264 for (size_t I = 0; I < N; I++) {
265 if (!(PcIsFuncEntry(TE: &PCTE.Start[I]))) continue; // not a function entry.
266 auto Name = DescribePC(SymbolizedFMT: "%F", PC: GetNextInstructionPc(PC: PCTE.Start[I].PC));
267 if (Name[0] == 'i' && Name[1] == 'n' && Name[2] == ' ')
268 Name = Name.substr(pos: 3, n: std::string::npos);
269 if (FuncName != Name) continue;
270 Printf(Fmt: "INFO: Focus function is set to '%s'\n", Name.c_str());
271 FocusFunctionCounterPtr = Modules[M].Start() + I;
272 return;
273 }
274 }
275
276 Printf(Fmt: "ERROR: Failed to set focus function. Make sure the function name is "
277 "valid (%s) and symbolization is enabled.\n", FuncName.c_str());
278 exit(status: 1);
279}
280
281bool TracePC::ObservedFocusFunction() {
282 return FocusFunctionCounterPtr && *FocusFunctionCounterPtr;
283}
284
285void TracePC::PrintCoverage(bool PrintAllCounters) {
286 if (!EF->__sanitizer_symbolize_pc ||
287 !EF->__sanitizer_get_module_and_offset_for_pc) {
288 Printf(Fmt: "INFO: __sanitizer_symbolize_pc or "
289 "__sanitizer_get_module_and_offset_for_pc is not available,"
290 " not printing coverage\n");
291 return;
292 }
293 Printf(Fmt: PrintAllCounters ? "FULL COVERAGE:\n" : "COVERAGE:\n");
294 auto CoveredFunctionCallback = [&](const PCTableEntry *First,
295 const PCTableEntry *Last,
296 uintptr_t Counter) {
297 assert(First < Last);
298 auto VisualizePC = GetNextInstructionPc(PC: First->PC);
299 std::string FileStr = DescribePC(SymbolizedFMT: "%s", PC: VisualizePC);
300 if (!IsInterestingCoverageFile(FileName: FileStr))
301 return;
302 std::string FunctionStr = DescribePC(SymbolizedFMT: "%F", PC: VisualizePC);
303 if (FunctionStr.find(s: "in ") == 0)
304 FunctionStr = FunctionStr.substr(pos: 3);
305 std::string LineStr = DescribePC(SymbolizedFMT: "%l", PC: VisualizePC);
306 size_t NumEdges = Last - First;
307 std::vector<uintptr_t> UncoveredPCs;
308 std::vector<uintptr_t> CoveredPCs;
309 for (auto TE = First; TE < Last; TE++)
310 if (!ObservedPCs.count(k: TE))
311 UncoveredPCs.push_back(x: TE->PC);
312 else
313 CoveredPCs.push_back(x: TE->PC);
314
315 if (PrintAllCounters) {
316 Printf(Fmt: "U");
317 for (auto PC : UncoveredPCs)
318 Printf(Fmt: DescribePC(SymbolizedFMT: " %l", PC: GetNextInstructionPc(PC)).c_str());
319 Printf(Fmt: "\n");
320
321 Printf(Fmt: "C");
322 for (auto PC : CoveredPCs)
323 Printf(Fmt: DescribePC(SymbolizedFMT: " %l", PC: GetNextInstructionPc(PC)).c_str());
324 Printf(Fmt: "\n");
325 } else {
326 Printf(Fmt: "%sCOVERED_FUNC: hits: %zd", Counter ? "" : "UN", Counter);
327 Printf(Fmt: " edges: %zd/%zd", NumEdges - UncoveredPCs.size(), NumEdges);
328 Printf(Fmt: " %s %s:%s\n", FunctionStr.c_str(), FileStr.c_str(),
329 LineStr.c_str());
330 if (Counter)
331 for (auto PC : UncoveredPCs)
332 Printf(Fmt: " UNCOVERED_PC: %s\n",
333 DescribePC(SymbolizedFMT: "%s:%l", PC: GetNextInstructionPc(PC)).c_str());
334 }
335 };
336
337 IterateCoveredFunctions(CB: CoveredFunctionCallback);
338}
339
340// Value profile.
341// We keep track of various values that affect control flow.
342// These values are inserted into a bit-set-based hash map.
343// Every new bit in the map is treated as a new coverage.
344//
345// For memcmp/strcmp/etc the interesting value is the length of the common
346// prefix of the parameters.
347// For cmp instructions the interesting value is a XOR of the parameters.
348// The interesting value is mixed up with the PC and is then added to the map.
349
350ATTRIBUTE_NO_SANITIZE_ALL
351void TracePC::AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2,
352 size_t n, bool StopAtZero) {
353 if (!n) return;
354 size_t Len = std::min(a: n, b: Word::GetMaxSize());
355 const uint8_t *A1 = reinterpret_cast<const uint8_t *>(s1);
356 const uint8_t *A2 = reinterpret_cast<const uint8_t *>(s2);
357 uint8_t B1[Word::kMaxSize];
358 uint8_t B2[Word::kMaxSize];
359 // Copy the data into locals in this non-msan-instrumented function
360 // to avoid msan complaining further.
361 size_t Hash = 0; // Compute some simple hash of both strings.
362 for (size_t i = 0; i < Len; i++) {
363 B1[i] = A1[i];
364 B2[i] = A2[i];
365 size_t T = B1[i];
366 Hash ^= (T << 8) | B2[i];
367 }
368 size_t I = 0;
369 uint8_t HammingDistance = 0;
370 for (; I < Len; I++) {
371 if (B1[I] != B2[I] || (StopAtZero && B1[I] == 0)) {
372 HammingDistance = static_cast<uint8_t>(Popcountll(X: B1[I] ^ B2[I]));
373 break;
374 }
375 }
376 size_t PC = reinterpret_cast<size_t>(caller_pc);
377 size_t Idx = (PC & 4095) | (I << 12);
378 Idx += HammingDistance;
379 ValueProfileMap.AddValue(Value: Idx);
380 TORCW.Insert(Idx: Idx ^ Hash, Arg1: Word(B1, Len), Arg2: Word(B2, Len));
381}
382
383template <class T>
384ATTRIBUTE_TARGET_POPCNT ALWAYS_INLINE
385ATTRIBUTE_NO_SANITIZE_ALL
386void TracePC::HandleCmp(uintptr_t PC, T Arg1, T Arg2) {
387 uint64_t ArgXor = Arg1 ^ Arg2;
388 if (sizeof(T) == 4)
389 TORC4.Insert(Idx: ArgXor, Arg1, Arg2);
390 else if (sizeof(T) == 8)
391 TORC8.Insert(Idx: ArgXor, Arg1, Arg2);
392 uint64_t HammingDistance = Popcountll(X: ArgXor); // [0,64]
393 uint64_t AbsoluteDistance = (Arg1 == Arg2 ? 0 : Clzll(Arg1 - Arg2) + 1);
394 ValueProfileMap.AddValue(Value: PC * 128 + HammingDistance);
395 ValueProfileMap.AddValue(Value: PC * 128 + 64 + AbsoluteDistance);
396}
397
398ATTRIBUTE_NO_SANITIZE_MEMORY
399static size_t InternalStrnlen(const char *S, size_t MaxLen) {
400 size_t Len = 0;
401 for (; Len < MaxLen && S[Len]; Len++) {}
402 return Len;
403}
404
405// Finds min of (strlen(S1), strlen(S2)).
406// Needed because one of these strings may actually be non-zero terminated.
407ATTRIBUTE_NO_SANITIZE_MEMORY
408static size_t InternalStrnlen2(const char *S1, const char *S2) {
409 size_t Len = 0;
410 for (; S1[Len] && S2[Len]; Len++) {}
411 return Len;
412}
413
414void TracePC::ClearInlineCounters() {
415 IterateCounterRegions(CB: [](const Module::Region &R){
416 if (R.Enabled)
417 memset(s: R.Start, c: 0, n: R.Stop - R.Start);
418 });
419}
420
421ATTRIBUTE_NO_SANITIZE_ALL
422void TracePC::RecordInitialStack() {
423 int stack;
424 __sancov_lowest_stack = InitialStack = reinterpret_cast<uintptr_t>(&stack);
425}
426
427uintptr_t TracePC::GetMaxStackOffset() const {
428 return InitialStack - __sancov_lowest_stack; // Stack grows down
429}
430
431void WarnAboutDeprecatedInstrumentation(const char *flag) {
432 // Use RawPrint because Printf cannot be used on Windows before OutputFile is
433 // initialized.
434 RawPrint(Str: flag);
435 RawPrint(
436 Str: " is no longer supported by libFuzzer.\n"
437 "Please either migrate to a compiler that supports -fsanitize=fuzzer\n"
438 "or use an older version of libFuzzer\n");
439 exit(status: 1);
440}
441
442} // namespace fuzzer
443
444extern "C" {
445ATTRIBUTE_INTERFACE
446ATTRIBUTE_NO_SANITIZE_ALL
447void __sanitizer_cov_trace_pc_guard(uint32_t *Guard) {
448 fuzzer::WarnAboutDeprecatedInstrumentation(
449 flag: "-fsanitize-coverage=trace-pc-guard");
450}
451
452// Best-effort support for -fsanitize-coverage=trace-pc, which is available
453// in both Clang and GCC.
454ATTRIBUTE_INTERFACE
455ATTRIBUTE_NO_SANITIZE_ALL
456void __sanitizer_cov_trace_pc() {
457 fuzzer::WarnAboutDeprecatedInstrumentation(flag: "-fsanitize-coverage=trace-pc");
458}
459
460ATTRIBUTE_INTERFACE
461void __sanitizer_cov_trace_pc_guard_init(uint32_t *Start, uint32_t *Stop) {
462 fuzzer::WarnAboutDeprecatedInstrumentation(
463 flag: "-fsanitize-coverage=trace-pc-guard");
464}
465
466ATTRIBUTE_INTERFACE
467void __sanitizer_cov_8bit_counters_init(uint8_t *Start, uint8_t *Stop) {
468 fuzzer::TPC.HandleInline8bitCountersInit(Start, Stop);
469}
470
471ATTRIBUTE_INTERFACE
472void __sanitizer_cov_pcs_init(const uintptr_t *pcs_beg,
473 const uintptr_t *pcs_end) {
474 fuzzer::TPC.HandlePCsInit(Start: pcs_beg, Stop: pcs_end);
475}
476
477ATTRIBUTE_INTERFACE
478ATTRIBUTE_NO_SANITIZE_ALL
479void __sanitizer_cov_trace_pc_indir(uintptr_t Callee) {
480 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
481 fuzzer::TPC.HandleCallerCallee(Caller: PC, Callee);
482}
483
484ATTRIBUTE_INTERFACE
485ATTRIBUTE_NO_SANITIZE_ALL
486ATTRIBUTE_TARGET_POPCNT
487void __sanitizer_cov_trace_cmp8(uint64_t Arg1, uint64_t Arg2) {
488 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
489 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
490}
491
492ATTRIBUTE_INTERFACE
493ATTRIBUTE_NO_SANITIZE_ALL
494ATTRIBUTE_TARGET_POPCNT
495// Now the __sanitizer_cov_trace_const_cmp[1248] callbacks just mimic
496// the behaviour of __sanitizer_cov_trace_cmp[1248] ones. This, however,
497// should be changed later to make full use of instrumentation.
498void __sanitizer_cov_trace_const_cmp8(uint64_t Arg1, uint64_t Arg2) {
499 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
500 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
501}
502
503ATTRIBUTE_INTERFACE
504ATTRIBUTE_NO_SANITIZE_ALL
505ATTRIBUTE_TARGET_POPCNT
506void __sanitizer_cov_trace_cmp4(uint32_t Arg1, uint32_t Arg2) {
507 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
508 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
509}
510
511ATTRIBUTE_INTERFACE
512ATTRIBUTE_NO_SANITIZE_ALL
513ATTRIBUTE_TARGET_POPCNT
514void __sanitizer_cov_trace_const_cmp4(uint32_t Arg1, uint32_t Arg2) {
515 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
516 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
517}
518
519ATTRIBUTE_INTERFACE
520ATTRIBUTE_NO_SANITIZE_ALL
521ATTRIBUTE_TARGET_POPCNT
522void __sanitizer_cov_trace_cmp2(uint16_t Arg1, uint16_t Arg2) {
523 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
524 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
525}
526
527ATTRIBUTE_INTERFACE
528ATTRIBUTE_NO_SANITIZE_ALL
529ATTRIBUTE_TARGET_POPCNT
530void __sanitizer_cov_trace_const_cmp2(uint16_t Arg1, uint16_t Arg2) {
531 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
532 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
533}
534
535ATTRIBUTE_INTERFACE
536ATTRIBUTE_NO_SANITIZE_ALL
537ATTRIBUTE_TARGET_POPCNT
538void __sanitizer_cov_trace_cmp1(uint8_t Arg1, uint8_t Arg2) {
539 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
540 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
541}
542
543ATTRIBUTE_INTERFACE
544ATTRIBUTE_NO_SANITIZE_ALL
545ATTRIBUTE_TARGET_POPCNT
546void __sanitizer_cov_trace_const_cmp1(uint8_t Arg1, uint8_t Arg2) {
547 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
548 fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
549}
550
551ATTRIBUTE_INTERFACE
552ATTRIBUTE_NO_SANITIZE_ALL
553ATTRIBUTE_TARGET_POPCNT
554void __sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases) {
555 uint64_t N = Cases[0];
556 uint64_t ValSizeInBits = Cases[1];
557 uint64_t *Vals = Cases + 2;
558 // Skip the most common and the most boring case: all switch values are small.
559 // We may want to skip this at compile-time, but it will make the
560 // instrumentation less general.
561 if (Vals[N - 1] < 256)
562 return;
563 // Also skip small inputs values, they won't give good signal.
564 if (Val < 256)
565 return;
566 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
567 size_t i;
568 uint64_t Smaller = 0;
569 uint64_t Larger = ~(uint64_t)0;
570 // Find two switch values such that Smaller < Val < Larger.
571 // Use 0 and 0xfff..f as the defaults.
572 for (i = 0; i < N; i++) {
573 if (Val < Vals[i]) {
574 Larger = Vals[i];
575 break;
576 }
577 if (Val > Vals[i]) Smaller = Vals[i];
578 }
579
580 // Apply HandleCmp to {Val,Smaller} and {Val, Larger},
581 // use i as the PC modifier for HandleCmp.
582 if (ValSizeInBits == 16) {
583 fuzzer::TPC.HandleCmp(PC: PC + 2 * i, Arg1: static_cast<uint16_t>(Val),
584 Arg2: (uint16_t)(Smaller));
585 fuzzer::TPC.HandleCmp(PC: PC + 2 * i + 1, Arg1: static_cast<uint16_t>(Val),
586 Arg2: (uint16_t)(Larger));
587 } else if (ValSizeInBits == 32) {
588 fuzzer::TPC.HandleCmp(PC: PC + 2 * i, Arg1: static_cast<uint32_t>(Val),
589 Arg2: (uint32_t)(Smaller));
590 fuzzer::TPC.HandleCmp(PC: PC + 2 * i + 1, Arg1: static_cast<uint32_t>(Val),
591 Arg2: (uint32_t)(Larger));
592 } else {
593 fuzzer::TPC.HandleCmp(PC: PC + 2*i, Arg1: Val, Arg2: Smaller);
594 fuzzer::TPC.HandleCmp(PC: PC + 2*i + 1, Arg1: Val, Arg2: Larger);
595 }
596}
597
598ATTRIBUTE_INTERFACE
599ATTRIBUTE_NO_SANITIZE_ALL
600ATTRIBUTE_TARGET_POPCNT
601void __sanitizer_cov_trace_div4(uint32_t Val) {
602 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
603 fuzzer::TPC.HandleCmp(PC, Arg1: Val, Arg2: (uint32_t)0);
604}
605
606ATTRIBUTE_INTERFACE
607ATTRIBUTE_NO_SANITIZE_ALL
608ATTRIBUTE_TARGET_POPCNT
609void __sanitizer_cov_trace_div8(uint64_t Val) {
610 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
611 fuzzer::TPC.HandleCmp(PC, Arg1: Val, Arg2: (uint64_t)0);
612}
613
614ATTRIBUTE_INTERFACE
615ATTRIBUTE_NO_SANITIZE_ALL
616ATTRIBUTE_TARGET_POPCNT
617void __sanitizer_cov_trace_gep(uintptr_t Idx) {
618 uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
619 fuzzer::TPC.HandleCmp(PC, Arg1: Idx, Arg2: (uintptr_t)0);
620}
621
622ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
623void __sanitizer_weak_hook_memcmp(void *caller_pc, const void *s1,
624 const void *s2, size_t n, int result) {
625 if (!fuzzer::RunningUserCallback) return;
626 if (result == 0) return; // No reason to mutate.
627 if (n <= 1) return; // Not interesting.
628 fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n, /*StopAtZero*/false);
629}
630
631ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
632void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1,
633 const char *s2, size_t n, int result) {
634 if (!fuzzer::RunningUserCallback) return;
635 if (result == 0) return; // No reason to mutate.
636 size_t Len1 = fuzzer::InternalStrnlen(S: s1, MaxLen: n);
637 size_t Len2 = fuzzer::InternalStrnlen(S: s2, MaxLen: n);
638 n = std::min(a: n, b: Len1);
639 n = std::min(a: n, b: Len2);
640 if (n <= 1) return; // Not interesting.
641 fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n, /*StopAtZero*/true);
642}
643
644ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
645void __sanitizer_weak_hook_strcmp(void *caller_pc, const char *s1,
646 const char *s2, int result) {
647 if (!fuzzer::RunningUserCallback) return;
648 if (result == 0) return; // No reason to mutate.
649 size_t N = fuzzer::InternalStrnlen2(S1: s1, S2: s2);
650 if (N <= 1) return; // Not interesting.
651 fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n: N, /*StopAtZero*/true);
652}
653
654ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
655void __sanitizer_weak_hook_strncasecmp(void *called_pc, const char *s1,
656 const char *s2, size_t n, int result) {
657 if (!fuzzer::RunningUserCallback) return;
658 return __sanitizer_weak_hook_strncmp(caller_pc: called_pc, s1, s2, n, result);
659}
660
661ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
662void __sanitizer_weak_hook_strcasecmp(void *called_pc, const char *s1,
663 const char *s2, int result) {
664 if (!fuzzer::RunningUserCallback) return;
665 return __sanitizer_weak_hook_strcmp(caller_pc: called_pc, s1, s2, result);
666}
667
668ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
669void __sanitizer_weak_hook_strstr(void *called_pc, const char *s1,
670 const char *s2, char *result) {
671 if (!fuzzer::RunningUserCallback) return;
672 fuzzer::TPC.MMT.Add(Data: reinterpret_cast<const uint8_t *>(s2), Size: strlen(s: s2));
673}
674
675ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
676void __sanitizer_weak_hook_strcasestr(void *called_pc, const char *s1,
677 const char *s2, char *result) {
678 if (!fuzzer::RunningUserCallback) return;
679 fuzzer::TPC.MMT.Add(Data: reinterpret_cast<const uint8_t *>(s2), Size: strlen(s: s2));
680}
681
682ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
683void __sanitizer_weak_hook_memmem(void *called_pc, const void *s1, size_t len1,
684 const void *s2, size_t len2, void *result) {
685 if (!fuzzer::RunningUserCallback) return;
686 fuzzer::TPC.MMT.Add(Data: reinterpret_cast<const uint8_t *>(s2), Size: len2);
687}
688} // extern "C"
689