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335 lines
12 KiB
335 lines
12 KiB
//===- FuzzerTracePC.cpp - PC tracing--------------------------------------===// |
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// |
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// The LLVM Compiler Infrastructure |
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// |
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// This file is distributed under the University of Illinois Open Source |
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// License. See LICENSE.TXT for details. |
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// |
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//===----------------------------------------------------------------------===// |
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// Trace PCs. |
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// This module implements __sanitizer_cov_trace_pc_guard[_init], |
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// the callback required for -fsanitize-coverage=trace-pc-guard instrumentation. |
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// |
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//===----------------------------------------------------------------------===// |
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#include <map> |
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#include <set> |
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#include <sstream> |
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#include "FuzzerCorpus.h" |
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#include "FuzzerDefs.h" |
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#include "FuzzerDictionary.h" |
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#include "FuzzerExtFunctions.h" |
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#include "FuzzerTracePC.h" |
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#include "FuzzerValueBitMap.h" |
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namespace fuzzer { |
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TracePC TPC; |
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void TracePC::HandleTrace(uint32_t *Guard, uintptr_t PC) { |
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uint32_t Idx = *Guard; |
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if (!Idx) return; |
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PCs[Idx % kNumPCs] = PC; |
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Counters[Idx % kNumCounters]++; |
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} |
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size_t TracePC::GetTotalPCCoverage() { |
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size_t Res = 0; |
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for (size_t i = 1; i < GetNumPCs(); i++) |
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if (PCs[i]) |
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Res++; |
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return Res; |
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} |
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void TracePC::HandleInit(uint32_t *Start, uint32_t *Stop) { |
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if (Start == Stop || *Start) return; |
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assert(NumModules < sizeof(Modules) / sizeof(Modules[0])); |
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for (uint32_t *P = Start; P < Stop; P++) |
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*P = ++NumGuards; |
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Modules[NumModules].Start = Start; |
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Modules[NumModules].Stop = Stop; |
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NumModules++; |
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} |
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void TracePC::PrintModuleInfo() { |
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Printf("INFO: Loaded %zd modules (%zd guards): ", NumModules, NumGuards); |
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for (size_t i = 0; i < NumModules; i++) |
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Printf("[%p, %p), ", Modules[i].Start, Modules[i].Stop); |
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Printf("\n"); |
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} |
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size_t TracePC::FinalizeTrace(InputCorpus *C, size_t InputSize, bool Shrink) { |
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if (!UsingTracePcGuard()) return 0; |
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size_t Res = 0; |
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const size_t Step = 8; |
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assert(reinterpret_cast<uintptr_t>(Counters) % Step == 0); |
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size_t N = Min(kNumCounters, NumGuards + 1); |
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N = (N + Step - 1) & ~(Step - 1); // Round up. |
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for (size_t Idx = 0; Idx < N; Idx += Step) { |
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uint64_t Bundle = *reinterpret_cast<uint64_t*>(&Counters[Idx]); |
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if (!Bundle) continue; |
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for (size_t i = Idx; i < Idx + Step; i++) { |
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uint8_t Counter = (Bundle >> (i * 8)) & 0xff; |
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if (!Counter) continue; |
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Counters[i] = 0; |
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unsigned Bit = 0; |
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/**/ if (Counter >= 128) Bit = 7; |
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else if (Counter >= 32) Bit = 6; |
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else if (Counter >= 16) Bit = 5; |
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else if (Counter >= 8) Bit = 4; |
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else if (Counter >= 4) Bit = 3; |
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else if (Counter >= 3) Bit = 2; |
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else if (Counter >= 2) Bit = 1; |
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size_t Feature = (i * 8 + Bit); |
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if (C->AddFeature(Feature, InputSize, Shrink)) |
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Res++; |
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} |
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} |
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if (UseValueProfile) |
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ValueProfileMap.ForEach([&](size_t Idx) { |
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if (C->AddFeature(NumGuards + Idx, InputSize, Shrink)) |
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Res++; |
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}); |
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return Res; |
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} |
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void TracePC::HandleCallerCallee(uintptr_t Caller, uintptr_t Callee) { |
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const uintptr_t kBits = 12; |
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const uintptr_t kMask = (1 << kBits) - 1; |
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uintptr_t Idx = (Caller & kMask) | ((Callee & kMask) << kBits); |
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HandleValueProfile(Idx); |
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} |
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static bool IsInterestingCoverageFile(std::string &File) { |
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if (File.find("compiler-rt/lib/") != std::string::npos) |
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return false; // sanitizer internal. |
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if (File.find("/usr/lib/") != std::string::npos) |
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return false; |
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if (File.find("/usr/include/") != std::string::npos) |
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return false; |
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if (File == "<null>") |
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return false; |
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return true; |
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} |
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void TracePC::PrintNewPCs() { |
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if (DoPrintNewPCs) { |
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if (!PrintedPCs) |
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PrintedPCs = new std::set<uintptr_t>; |
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for (size_t i = 1; i < GetNumPCs(); i++) |
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if (PCs[i] && PrintedPCs->insert(PCs[i]).second) |
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PrintPC("\tNEW_PC: %p %F %L\n", "\tNEW_PC: %p\n", PCs[i]); |
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} |
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} |
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void TracePC::PrintCoverage() { |
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if (!EF->__sanitizer_symbolize_pc) { |
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Printf("INFO: __sanitizer_symbolize_pc is not available," |
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" not printing coverage\n"); |
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return; |
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} |
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std::map<std::string, std::vector<uintptr_t>> CoveredPCsPerModule; |
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std::map<std::string, uintptr_t> ModuleOffsets; |
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std::set<std::string> CoveredFiles, CoveredFunctions, CoveredLines; |
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Printf("COVERAGE:\n"); |
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for (size_t i = 1; i < GetNumPCs(); i++) { |
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if (!PCs[i]) continue; |
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std::string FileStr = DescribePC("%s", PCs[i]); |
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if (!IsInterestingCoverageFile(FileStr)) continue; |
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std::string FixedPCStr = DescribePC("%p", PCs[i]); |
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std::string FunctionStr = DescribePC("%F", PCs[i]); |
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std::string LineStr = DescribePC("%l", PCs[i]); |
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// TODO(kcc): get the module using some other way since this |
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// does not work with ASAN_OPTIONS=strip_path_prefix=something. |
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std::string Module = DescribePC("%m", PCs[i]); |
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std::string OffsetStr = DescribePC("%o", PCs[i]); |
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uintptr_t FixedPC = std::stol(FixedPCStr, 0, 16); |
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uintptr_t PcOffset = std::stol(OffsetStr, 0, 16); |
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ModuleOffsets[Module] = FixedPC - PcOffset; |
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CoveredPCsPerModule[Module].push_back(PcOffset); |
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CoveredFunctions.insert(FunctionStr); |
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CoveredFiles.insert(FileStr); |
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if (!CoveredLines.insert(FileStr + ":" + LineStr).second) |
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continue; |
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Printf("COVERED: %s %s:%s\n", FunctionStr.c_str(), |
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FileStr.c_str(), LineStr.c_str()); |
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} |
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for (auto &M : CoveredPCsPerModule) { |
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std::set<std::string> UncoveredFiles, UncoveredFunctions; |
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std::map<std::string, std::set<int> > UncoveredLines; // Func+File => lines |
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auto &ModuleName = M.first; |
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auto &CoveredOffsets = M.second; |
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uintptr_t ModuleOffset = ModuleOffsets[ModuleName]; |
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std::sort(CoveredOffsets.begin(), CoveredOffsets.end()); |
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Printf("MODULE_WITH_COVERAGE: %s\n", ModuleName.c_str()); |
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// sancov does not yet fully support DSOs. |
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// std::string Cmd = "sancov -print-coverage-pcs " + ModuleName; |
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std::string Cmd = "objdump -d " + ModuleName + |
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" | grep 'call.*__sanitizer_cov_trace_pc_guard' | awk -F: '{print $1}'"; |
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std::string SanCovOutput; |
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if (!ExecuteCommandAndReadOutput(Cmd, &SanCovOutput)) { |
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Printf("INFO: Command failed: %s\n", Cmd.c_str()); |
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continue; |
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} |
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std::istringstream ISS(SanCovOutput); |
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std::string S; |
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while (std::getline(ISS, S, '\n')) { |
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uintptr_t PcOffset = std::stol(S, 0, 16); |
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if (!std::binary_search(CoveredOffsets.begin(), CoveredOffsets.end(), |
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PcOffset)) { |
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uintptr_t PC = ModuleOffset + PcOffset; |
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auto FileStr = DescribePC("%s", PC); |
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if (!IsInterestingCoverageFile(FileStr)) continue; |
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if (CoveredFiles.count(FileStr) == 0) { |
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UncoveredFiles.insert(FileStr); |
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continue; |
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} |
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auto FunctionStr = DescribePC("%F", PC); |
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if (CoveredFunctions.count(FunctionStr) == 0) { |
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UncoveredFunctions.insert(FunctionStr); |
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continue; |
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} |
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std::string LineStr = DescribePC("%l", PC); |
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uintptr_t Line = std::stoi(LineStr); |
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std::string FileLineStr = FileStr + ":" + LineStr; |
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if (CoveredLines.count(FileLineStr) == 0) |
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UncoveredLines[FunctionStr + " " + FileStr].insert(Line); |
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} |
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} |
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for (auto &FileLine: UncoveredLines) |
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for (int Line : FileLine.second) |
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Printf("UNCOVERED_LINE: %s:%d\n", FileLine.first.c_str(), Line); |
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for (auto &Func : UncoveredFunctions) |
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Printf("UNCOVERED_FUNC: %s\n", Func.c_str()); |
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for (auto &File : UncoveredFiles) |
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Printf("UNCOVERED_FILE: %s\n", File.c_str()); |
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} |
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} |
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// Value profile. |
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// We keep track of various values that affect control flow. |
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// These values are inserted into a bit-set-based hash map. |
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// Every new bit in the map is treated as a new coverage. |
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// |
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// For memcmp/strcmp/etc the interesting value is the length of the common |
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// prefix of the parameters. |
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// For cmp instructions the interesting value is a XOR of the parameters. |
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// The interesting value is mixed up with the PC and is then added to the map. |
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#ifdef __clang__ // avoid gcc warning. |
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__attribute__((no_sanitize("memory"))) |
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#endif |
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void TracePC::AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2, |
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size_t n) { |
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if (!n) return; |
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size_t Len = std::min(n, (size_t)32); |
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const uint8_t *A1 = reinterpret_cast<const uint8_t *>(s1); |
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const uint8_t *A2 = reinterpret_cast<const uint8_t *>(s2); |
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size_t I = 0; |
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for (; I < Len; I++) |
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if (A1[I] != A2[I]) |
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break; |
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size_t PC = reinterpret_cast<size_t>(caller_pc); |
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size_t Idx = I; |
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// if (I < Len) |
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// Idx += __builtin_popcountl((A1[I] ^ A2[I])) - 1; |
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TPC.HandleValueProfile((PC & 4095) | (Idx << 12)); |
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} |
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void TracePC::AddValueForStrcmp(void *caller_pc, const char *s1, const char *s2, |
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size_t n) { |
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if (!n) return; |
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size_t Len = std::min(n, (size_t)32); |
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const uint8_t *A1 = reinterpret_cast<const uint8_t *>(s1); |
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const uint8_t *A2 = reinterpret_cast<const uint8_t *>(s2); |
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size_t I = 0; |
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for (; I < Len; I++) |
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if (A1[I] != A2[I] || A1[I] == 0) |
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break; |
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size_t PC = reinterpret_cast<size_t>(caller_pc); |
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size_t Idx = I; |
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// if (I < Len && A1[I]) |
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// Idx += __builtin_popcountl((A1[I] ^ A2[I])) - 1; |
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TPC.HandleValueProfile((PC & 4095) | (Idx << 12)); |
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} |
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template <class T> |
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ATTRIBUTE_TARGET_POPCNT |
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#ifdef __clang__ // g++ can't handle this __attribute__ here :( |
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__attribute__((always_inline)) |
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#endif // __clang__ |
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void TracePC::HandleCmp(void *PC, T Arg1, T Arg2) { |
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uintptr_t PCuint = reinterpret_cast<uintptr_t>(PC); |
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uint64_t ArgXor = Arg1 ^ Arg2; |
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uint64_t ArgDistance = __builtin_popcountl(ArgXor) + 1; // [1,65] |
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uintptr_t Idx = ((PCuint & 4095) + 1) * ArgDistance; |
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if (sizeof(T) == 4) |
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TORC4.Insert(ArgXor, Arg1, Arg2); |
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else if (sizeof(T) == 8) |
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TORC8.Insert(ArgXor, Arg1, Arg2); |
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HandleValueProfile(Idx); |
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} |
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} // namespace fuzzer |
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extern "C" { |
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__attribute__((visibility("default"))) |
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void __sanitizer_cov_trace_pc_guard(uint32_t *Guard) { |
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uintptr_t PC = (uintptr_t)__builtin_return_address(0); |
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fuzzer::TPC.HandleTrace(Guard, PC); |
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} |
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__attribute__((visibility("default"))) |
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void __sanitizer_cov_trace_pc_guard_init(uint32_t *Start, uint32_t *Stop) { |
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fuzzer::TPC.HandleInit(Start, Stop); |
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} |
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__attribute__((visibility("default"))) |
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void __sanitizer_cov_trace_pc_indir(uintptr_t Callee) { |
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uintptr_t PC = (uintptr_t)__builtin_return_address(0); |
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fuzzer::TPC.HandleCallerCallee(PC, Callee); |
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} |
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__attribute__((visibility("default"))) |
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void __sanitizer_cov_trace_cmp8(uint64_t Arg1, uint64_t Arg2) { |
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fuzzer::TPC.HandleCmp(__builtin_return_address(0), Arg1, Arg2); |
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} |
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__attribute__((visibility("default"))) |
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void __sanitizer_cov_trace_cmp4(uint32_t Arg1, uint32_t Arg2) { |
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fuzzer::TPC.HandleCmp(__builtin_return_address(0), Arg1, Arg2); |
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} |
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__attribute__((visibility("default"))) |
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void __sanitizer_cov_trace_cmp2(uint16_t Arg1, uint16_t Arg2) { |
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fuzzer::TPC.HandleCmp(__builtin_return_address(0), Arg1, Arg2); |
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} |
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__attribute__((visibility("default"))) |
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void __sanitizer_cov_trace_cmp1(uint8_t Arg1, uint8_t Arg2) { |
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fuzzer::TPC.HandleCmp(__builtin_return_address(0), Arg1, Arg2); |
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} |
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__attribute__((visibility("default"))) |
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void __sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases) { |
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uint64_t N = Cases[0]; |
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uint64_t *Vals = Cases + 2; |
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char *PC = (char*)__builtin_return_address(0); |
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for (size_t i = 0; i < N; i++) |
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if (Val != Vals[i]) |
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fuzzer::TPC.HandleCmp(PC + i, Val, Vals[i]); |
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} |
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__attribute__((visibility("default"))) |
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void __sanitizer_cov_trace_div4(uint32_t Val) { |
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fuzzer::TPC.HandleCmp(__builtin_return_address(0), Val, (uint32_t)0); |
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} |
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__attribute__((visibility("default"))) |
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void __sanitizer_cov_trace_div8(uint64_t Val) { |
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fuzzer::TPC.HandleCmp(__builtin_return_address(0), Val, (uint64_t)0); |
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} |
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__attribute__((visibility("default"))) |
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void __sanitizer_cov_trace_gep(uintptr_t Idx) { |
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fuzzer::TPC.HandleCmp(__builtin_return_address(0), Idx, (uintptr_t)0); |
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} |
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} // extern "C"
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