if( LLVM_USE_SANITIZE_COVERAGE )
add_library(LLVMFuzzerNoMain OBJECT
FuzzerCrossOver.cpp
- FuzzerDFSan.cpp
+ FuzzerTraceState.cpp
FuzzerDriver.cpp
FuzzerIO.cpp
FuzzerLoop.cpp
+++ /dev/null
-//===- FuzzerDFSan.cpp - DFSan-based fuzzer mutator -----------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-// DataFlowSanitizer (DFSan) is a tool for
-// generalised dynamic data flow (taint) analysis:
-// http://clang.llvm.org/docs/DataFlowSanitizer.html .
-//
-// This file implements a mutation algorithm based on taint
-// analysis feedback from DFSan.
-//
-// The approach has some similarity to "Taint-based Directed Whitebox Fuzzing"
-// by Vijay Ganesh & Tim Leek & Martin Rinard:
-// http://dspace.mit.edu/openaccess-disseminate/1721.1/59320,
-// but it uses a full blown LLVM IR taint analysis and separate instrumentation
-// to analyze all of the "attack points" at once.
-//
-// Workflow:
-// * lib/Fuzzer/Fuzzer*.cpp is compiled w/o any instrumentation.
-// * The code under test is compiled with DFSan *and* with special extra hooks
-// that are inserted before dfsan. Currently supported hooks:
-// - __sanitizer_cov_trace_cmp: inserted before every ICMP instruction,
-// receives the type, size and arguments of ICMP.
-// * Every call to HOOK(a,b) is replaced by DFSan with
-// __dfsw_HOOK(a, b, label(a), label(b)) so that __dfsw_HOOK
-// gets all the taint labels for the arguments.
-// * At the Fuzzer startup we assign a unique DFSan label
-// to every byte of the input string (Fuzzer::CurrentUnit) so that for any
-// chunk of data we know which input bytes it has derived from.
-// * The __dfsw_* functions (implemented in this file) record the
-// parameters (i.e. the application data and the corresponding taint labels)
-// in a global state.
-// * Fuzzer::MutateWithDFSan() tries to use the data recorded by __dfsw_*
-// hooks to guide the fuzzing towards new application states.
-// For example if 4 bytes of data that derive from input bytes {4,5,6,7}
-// are compared with a constant 12345 and the comparison always yields
-// the same result, we try to insert 12345, 12344, 12346 into bytes
-// {4,5,6,7} of the next fuzzed inputs.
-//
-// This code does not function when DFSan is not linked in.
-// Instead of using ifdefs and thus requiring a separate build of lib/Fuzzer
-// we redeclare the dfsan_* interface functions as weak and check if they
-// are nullptr before calling.
-// If this approach proves to be useful we may add attribute(weak) to the
-// dfsan declarations in dfsan_interface.h
-//
-// This module is in the "proof of concept" stage.
-// It is capable of solving only the simplest puzzles
-// like test/dfsan/DFSanSimpleCmpTest.cpp.
-//===----------------------------------------------------------------------===//
-
-/* Example of manual usage:
-(
- cd $LLVM/lib/Fuzzer/
- clang -fPIC -c -g -O2 -std=c++11 Fuzzer*.cpp
- clang++ -O0 -std=c++11 -fsanitize-coverage=edge,trace-cmp \
- -fsanitize=dataflow \
- test/dfsan/DFSanSimpleCmpTest.cpp Fuzzer*.o
- ./a.out
-)
-*/
-
-#include "FuzzerInternal.h"
-#include <sanitizer/dfsan_interface.h>
-
-#include <algorithm>
-#include <cstring>
-#include <iostream>
-#include <unordered_map>
-
-extern "C" {
-__attribute__((weak))
-dfsan_label dfsan_create_label(const char *desc, void *userdata);
-__attribute__((weak))
-void dfsan_set_label(dfsan_label label, void *addr, size_t size);
-__attribute__((weak))
-void dfsan_add_label(dfsan_label label, void *addr, size_t size);
-__attribute__((weak))
-const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label);
-__attribute__((weak))
-dfsan_label dfsan_read_label(const void *addr, size_t size);
-} // extern "C"
-
-namespace fuzzer {
-
-static bool ReallyHaveDFSan() {
- return &dfsan_create_label != nullptr;
-}
-
-// These values are copied from include/llvm/IR/InstrTypes.h.
-// We do not include the LLVM headers here to remain independent.
-// If these values ever change, an assertion in ComputeCmp will fail.
-enum Predicate {
- ICMP_EQ = 32, ///< equal
- ICMP_NE = 33, ///< not equal
- ICMP_UGT = 34, ///< unsigned greater than
- ICMP_UGE = 35, ///< unsigned greater or equal
- ICMP_ULT = 36, ///< unsigned less than
- ICMP_ULE = 37, ///< unsigned less or equal
- ICMP_SGT = 38, ///< signed greater than
- ICMP_SGE = 39, ///< signed greater or equal
- ICMP_SLT = 40, ///< signed less than
- ICMP_SLE = 41, ///< signed less or equal
-};
-
-template <class U, class S>
-bool ComputeCmp(size_t CmpType, U Arg1, U Arg2) {
- switch(CmpType) {
- case ICMP_EQ : return Arg1 == Arg2;
- case ICMP_NE : return Arg1 != Arg2;
- case ICMP_UGT: return Arg1 > Arg2;
- case ICMP_UGE: return Arg1 >= Arg2;
- case ICMP_ULT: return Arg1 < Arg2;
- case ICMP_ULE: return Arg1 <= Arg2;
- case ICMP_SGT: return (S)Arg1 > (S)Arg2;
- case ICMP_SGE: return (S)Arg1 >= (S)Arg2;
- case ICMP_SLT: return (S)Arg1 < (S)Arg2;
- case ICMP_SLE: return (S)Arg1 <= (S)Arg2;
- default: assert(0 && "unsupported CmpType");
- }
- return false;
-}
-
-static bool ComputeCmp(size_t CmpSize, size_t CmpType, uint64_t Arg1,
- uint64_t Arg2) {
- if (CmpSize == 8) return ComputeCmp<uint64_t, int64_t>(CmpType, Arg1, Arg2);
- if (CmpSize == 4) return ComputeCmp<uint32_t, int32_t>(CmpType, Arg1, Arg2);
- if (CmpSize == 2) return ComputeCmp<uint16_t, int16_t>(CmpType, Arg1, Arg2);
- if (CmpSize == 1) return ComputeCmp<uint8_t, int8_t>(CmpType, Arg1, Arg2);
- assert(0 && "unsupported type size");
- return true;
-}
-
-// As a simplification we use the range of input bytes instead of a set of input
-// bytes.
-struct LabelRange {
- uint16_t Beg, End; // Range is [Beg, End), thus Beg==End is an empty range.
-
- LabelRange(uint16_t Beg = 0, uint16_t End = 0) : Beg(Beg), End(End) {}
-
- static LabelRange Join(LabelRange LR1, LabelRange LR2) {
- if (LR1.Beg == LR1.End) return LR2;
- if (LR2.Beg == LR2.End) return LR1;
- return {std::min(LR1.Beg, LR2.Beg), std::max(LR1.End, LR2.End)};
- }
- LabelRange &Join(LabelRange LR) {
- return *this = Join(*this, LR);
- }
- static LabelRange Singleton(const dfsan_label_info *LI) {
- uint16_t Idx = (uint16_t)(uintptr_t)LI->userdata;
- assert(Idx > 0);
- return {(uint16_t)(Idx - 1), Idx};
- }
-};
-
-std::ostream &operator<<(std::ostream &os, const LabelRange &LR) {
- return os << "[" << LR.Beg << "," << LR.End << ")";
-}
-
-// For now, very simple: put Size bytes of Data at position Pos.
-struct TraceBasedMutation {
- size_t Pos;
- size_t Size;
- uint64_t Data;
-};
-
-class DFSanState {
- public:
- DFSanState(const Fuzzer::FuzzingOptions &Options, const Unit &CurrentUnit)
- : Options(Options), CurrentUnit(CurrentUnit) {}
-
- LabelRange GetLabelRange(dfsan_label L);
- void DFSanCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
- uint64_t Arg1, uint64_t Arg2, dfsan_label L1,
- dfsan_label L2);
- void TraceCmpCallback(size_t CmpSize, size_t CmpType, uint64_t Arg1,
- uint64_t Arg2);
- int TryToAddDesiredData(uint64_t PresentData, uint64_t DesiredData,
- size_t DataSize);
-
- void StartTraceRecording() {
- RecordingTraces = true;
- Mutations.clear();
- }
-
- size_t StopTraceRecording() {
- RecordingTraces = false;
- std::random_shuffle(Mutations.begin(), Mutations.end());
- return Mutations.size();
- }
-
- void ApplyTraceBasedMutation(size_t Idx, fuzzer::Unit *U);
-
- private:
- bool IsTwoByteData(uint64_t Data) {
- int64_t Signed = static_cast<int64_t>(Data);
- Signed >>= 16;
- return Signed == 0 || Signed == -1L;
- }
- bool RecordingTraces = false;
- std::vector<TraceBasedMutation> Mutations;
- LabelRange LabelRanges[1 << (sizeof(dfsan_label) * 8)] = {};
- const Fuzzer::FuzzingOptions &Options;
- const Unit &CurrentUnit;
-};
-
-LabelRange DFSanState::GetLabelRange(dfsan_label L) {
- LabelRange &LR = LabelRanges[L];
- if (LR.Beg < LR.End || L == 0)
- return LR;
- const dfsan_label_info *LI = dfsan_get_label_info(L);
- if (LI->l1 || LI->l2)
- return LR = LabelRange::Join(GetLabelRange(LI->l1), GetLabelRange(LI->l2));
- return LR = LabelRange::Singleton(LI);
-}
-
-void DFSanState::ApplyTraceBasedMutation(size_t Idx, fuzzer::Unit *U) {
- assert(Idx < Mutations.size());
- auto &M = Mutations[Idx];
- if (Options.Verbosity >= 3)
- std::cerr << "TBM " << M.Pos << " " << M.Size << " " << M.Data << "\n";
- if (M.Pos + M.Size > U->size()) return;
- memcpy(U->data() + M.Pos, &M.Data, M.Size);
-}
-
-void DFSanState::DFSanCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
- uint64_t Arg1, uint64_t Arg2, dfsan_label L1,
- dfsan_label L2) {
- assert(ReallyHaveDFSan());
- if (!RecordingTraces) return;
- if (L1 == 0 && L2 == 0)
- return; // Not actionable.
- if (L1 != 0 && L2 != 0)
- return; // Probably still actionable.
- bool Res = ComputeCmp(CmpSize, CmpType, Arg1, Arg2);
- uint64_t Data = L1 ? Arg2 : Arg1;
- LabelRange LR = L1 ? GetLabelRange(L1) : GetLabelRange(L2);
-
- for (size_t Pos = LR.Beg; Pos + CmpSize <= LR.End; Pos++) {
- Mutations.push_back({Pos, CmpSize, Data});
- Mutations.push_back({Pos, CmpSize, Data + 1});
- Mutations.push_back({Pos, CmpSize, Data - 1});
- }
-
- if (CmpSize > LR.End - LR.Beg)
- Mutations.push_back({LR.Beg, (unsigned)(LR.End - LR.Beg), Data});
-
-
- if (Options.Verbosity >= 3)
- std::cerr << "DFSAN:"
- << " PC " << std::hex << PC << std::dec
- << " S " << CmpSize
- << " T " << CmpType
- << " A1 " << Arg1 << " A2 " << Arg2 << " R " << Res
- << " L" << L1
- << " L" << L2
- << " R" << LR
- << " MU " << Mutations.size()
- << "\n";
-}
-
-int DFSanState::TryToAddDesiredData(uint64_t PresentData, uint64_t DesiredData,
- size_t DataSize) {
- int Res = 0;
- const uint8_t *Beg = CurrentUnit.data();
- const uint8_t *End = Beg + CurrentUnit.size();
- for (const uint8_t *Cur = Beg; Cur < End; Cur += DataSize) {
- Cur = (uint8_t *)memmem(Cur, End - Cur, &PresentData, DataSize);
- if (!Cur)
- break;
- // std::cerr << "Cur " << (void*)Cur << "\n";
- size_t Pos = Cur - Beg;
- assert(Pos < CurrentUnit.size());
- Mutations.push_back({Pos, DataSize, DesiredData});
- Mutations.push_back({Pos, DataSize, DesiredData + 1});
- Mutations.push_back({Pos, DataSize, DesiredData - 1});
- Cur += DataSize;
- Res++;
- }
- return Res;
-}
-
-void DFSanState::TraceCmpCallback(size_t CmpSize, size_t CmpType, uint64_t Arg1,
- uint64_t Arg2) {
- if (!Options.UseTraces) return;
- int Added = 0;
- if (Options.Verbosity >= 3)
- std::cerr << "TraceCmp: " << Arg1 << " " << Arg2 << "\n";
- Added += TryToAddDesiredData(Arg1, Arg2, CmpSize);
- Added += TryToAddDesiredData(Arg2, Arg1, CmpSize);
- if (!Added && CmpSize == 4 && IsTwoByteData(Arg1) && IsTwoByteData(Arg2)) {
- Added += TryToAddDesiredData(Arg1, Arg2, 2);
- Added += TryToAddDesiredData(Arg2, Arg1, 2);
- }
-}
-
-static DFSanState *DFSan;
-
-void Fuzzer::StartTraceRecording() {
- if (!DFSan) return;
- DFSan->StartTraceRecording();
-}
-
-size_t Fuzzer::StopTraceRecording() {
- if (!DFSan) return 0;
- return DFSan->StopTraceRecording();
-}
-
-void Fuzzer::ApplyTraceBasedMutation(size_t Idx, Unit *U) {
- assert(DFSan);
- DFSan->ApplyTraceBasedMutation(Idx, U);
-}
-
-void Fuzzer::InitializeDFSan() {
- if (!Options.UseDFSan) return;
- DFSan = new DFSanState(Options, CurrentUnit);
- CurrentUnit.resize(Options.MaxLen);
- // The rest really requires DFSan.
- if (!ReallyHaveDFSan()) return;
- for (size_t i = 0; i < static_cast<size_t>(Options.MaxLen); i++) {
- dfsan_label L = dfsan_create_label("input", (void*)(i + 1));
- // We assume that no one else has called dfsan_create_label before.
- assert(L == i + 1);
- dfsan_set_label(L, &CurrentUnit[i], 1);
- }
-}
-
-} // namespace fuzzer
-
-using fuzzer::DFSan;
-
-extern "C" {
-void __dfsw___sanitizer_cov_trace_cmp(uint64_t SizeAndType, uint64_t Arg1,
- uint64_t Arg2, dfsan_label L0,
- dfsan_label L1, dfsan_label L2) {
- assert(L0 == 0);
- uintptr_t PC = reinterpret_cast<uintptr_t>(__builtin_return_address(0));
- uint64_t CmpSize = (SizeAndType >> 32) / 8;
- uint64_t Type = (SizeAndType << 32) >> 32;
- DFSan->DFSanCmpCallback(PC, CmpSize, Type, Arg1, Arg2, L1, L2);
-}
-
-void dfsan_weak_hook_memcmp(void *caller_pc, const void *s1, const void *s2,
- size_t n, dfsan_label s1_label,
- dfsan_label s2_label, dfsan_label n_label) {
- uintptr_t PC = reinterpret_cast<uintptr_t>(caller_pc);
- uint64_t S1 = 0, S2 = 0;
- // Simplification: handle only first 8 bytes.
- memcpy(&S1, s1, std::min(n, sizeof(S1)));
- memcpy(&S2, s2, std::min(n, sizeof(S2)));
- dfsan_label L1 = dfsan_read_label(s1, n);
- dfsan_label L2 = dfsan_read_label(s2, n);
- DFSan->DFSanCmpCallback(PC, n, fuzzer::ICMP_EQ, S1, S2, L1, L2);
-}
-
-void __sanitizer_cov_trace_cmp(uint64_t SizeAndType, uint64_t Arg1,
- uint64_t Arg2) {
- if (!DFSan) return;
- uint64_t CmpSize = (SizeAndType >> 32) / 8;
- uint64_t Type = (SizeAndType << 32) >> 32;
- DFSan->TraceCmpCallback(CmpSize, Type, Arg1, Arg2);
-}
-
-} // extern "C"
void AddToCorpus(const Unit &U) { Corpus.push_back(U); }
void Loop(size_t NumIterations);
void ShuffleAndMinimize();
- void InitializeDFSan();
+ void InitializeTraceState();
size_t CorpusSize() const { return Corpus.size(); }
void ReadDir(const std::string &Path, long *Epoch) {
ReadDirToVectorOfUnits(Path.c_str(), &Corpus, Epoch);
Fuzzer::Fuzzer(UserCallback Callback, FuzzingOptions Options)
: Callback(Callback), Options(Options) {
SetDeathCallback();
- InitializeDFSan();
+ InitializeTraceState();
assert(!F);
F = this;
}
--- /dev/null
+//===- FuzzerTraceState.cpp - Trace-based fuzzer mutator ------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This file implements a mutation algorithm based on instruction traces and
+// on taint analysis feedback from DFSan.
+//
+// Instruction traces are special hooks inserted by the compiler around
+// interesting instructions. Currently supported traces:
+// * __sanitizer_cov_trace_cmp -- inserted before every ICMP instruction,
+// receives the type, size and arguments of ICMP.
+//
+// Every time a traced event is intercepted we analyse the data involved
+// in the event and suggest a mutation for future executions.
+// For example if 4 bytes of data that derive from input bytes {4,5,6,7}
+// are compared with a constant 12345,
+// we try to insert 12345, 12344, 12346 into bytes
+// {4,5,6,7} of the next fuzzed inputs.
+//
+// The fuzzer can work only with the traces, or with both traces and DFSan.
+//
+// DataFlowSanitizer (DFSan) is a tool for
+// generalised dynamic data flow (taint) analysis:
+// http://clang.llvm.org/docs/DataFlowSanitizer.html .
+//
+// The approach with DFSan-based fuzzing has some similarity to
+// "Taint-based Directed Whitebox Fuzzing"
+// by Vijay Ganesh & Tim Leek & Martin Rinard:
+// http://dspace.mit.edu/openaccess-disseminate/1721.1/59320,
+// but it uses a full blown LLVM IR taint analysis and separate instrumentation
+// to analyze all of the "attack points" at once.
+//
+// Workflow with DFSan:
+// * lib/Fuzzer/Fuzzer*.cpp is compiled w/o any instrumentation.
+// * The code under test is compiled with DFSan *and* with instruction traces.
+// * Every call to HOOK(a,b) is replaced by DFSan with
+// __dfsw_HOOK(a, b, label(a), label(b)) so that __dfsw_HOOK
+// gets all the taint labels for the arguments.
+// * At the Fuzzer startup we assign a unique DFSan label
+// to every byte of the input string (Fuzzer::CurrentUnit) so that for any
+// chunk of data we know which input bytes it has derived from.
+// * The __dfsw_* functions (implemented in this file) record the
+// parameters (i.e. the application data and the corresponding taint labels)
+// in a global state.
+// * Fuzzer::ApplyTraceBasedMutation() tries to use the data recorded
+// by __dfsw_* hooks to guide the fuzzing towards new application states.
+//
+// Parts of this code will not function when DFSan is not linked in.
+// Instead of using ifdefs and thus requiring a separate build of lib/Fuzzer
+// we redeclare the dfsan_* interface functions as weak and check if they
+// are nullptr before calling.
+// If this approach proves to be useful we may add attribute(weak) to the
+// dfsan declarations in dfsan_interface.h
+//
+// This module is in the "proof of concept" stage.
+// It is capable of solving only the simplest puzzles
+// like test/dfsan/DFSanSimpleCmpTest.cpp.
+//===----------------------------------------------------------------------===//
+
+/* Example of manual usage (-fsanitize=dataflow is optional):
+(
+ cd $LLVM/lib/Fuzzer/
+ clang -fPIC -c -g -O2 -std=c++11 Fuzzer*.cpp
+ clang++ -O0 -std=c++11 -fsanitize-coverage=edge,trace-cmp \
+ -fsanitize=dataflow \
+ test/dfsan/DFSanSimpleCmpTest.cpp Fuzzer*.o
+ ./a.out
+)
+*/
+
+#include "FuzzerInternal.h"
+#include <sanitizer/dfsan_interface.h>
+
+#include <algorithm>
+#include <cstring>
+#include <iostream>
+#include <unordered_map>
+
+extern "C" {
+__attribute__((weak))
+dfsan_label dfsan_create_label(const char *desc, void *userdata);
+__attribute__((weak))
+void dfsan_set_label(dfsan_label label, void *addr, size_t size);
+__attribute__((weak))
+void dfsan_add_label(dfsan_label label, void *addr, size_t size);
+__attribute__((weak))
+const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label);
+__attribute__((weak))
+dfsan_label dfsan_read_label(const void *addr, size_t size);
+} // extern "C"
+
+namespace fuzzer {
+
+static bool ReallyHaveDFSan() {
+ return &dfsan_create_label != nullptr;
+}
+
+// These values are copied from include/llvm/IR/InstrTypes.h.
+// We do not include the LLVM headers here to remain independent.
+// If these values ever change, an assertion in ComputeCmp will fail.
+enum Predicate {
+ ICMP_EQ = 32, ///< equal
+ ICMP_NE = 33, ///< not equal
+ ICMP_UGT = 34, ///< unsigned greater than
+ ICMP_UGE = 35, ///< unsigned greater or equal
+ ICMP_ULT = 36, ///< unsigned less than
+ ICMP_ULE = 37, ///< unsigned less or equal
+ ICMP_SGT = 38, ///< signed greater than
+ ICMP_SGE = 39, ///< signed greater or equal
+ ICMP_SLT = 40, ///< signed less than
+ ICMP_SLE = 41, ///< signed less or equal
+};
+
+template <class U, class S>
+bool ComputeCmp(size_t CmpType, U Arg1, U Arg2) {
+ switch(CmpType) {
+ case ICMP_EQ : return Arg1 == Arg2;
+ case ICMP_NE : return Arg1 != Arg2;
+ case ICMP_UGT: return Arg1 > Arg2;
+ case ICMP_UGE: return Arg1 >= Arg2;
+ case ICMP_ULT: return Arg1 < Arg2;
+ case ICMP_ULE: return Arg1 <= Arg2;
+ case ICMP_SGT: return (S)Arg1 > (S)Arg2;
+ case ICMP_SGE: return (S)Arg1 >= (S)Arg2;
+ case ICMP_SLT: return (S)Arg1 < (S)Arg2;
+ case ICMP_SLE: return (S)Arg1 <= (S)Arg2;
+ default: assert(0 && "unsupported CmpType");
+ }
+ return false;
+}
+
+static bool ComputeCmp(size_t CmpSize, size_t CmpType, uint64_t Arg1,
+ uint64_t Arg2) {
+ if (CmpSize == 8) return ComputeCmp<uint64_t, int64_t>(CmpType, Arg1, Arg2);
+ if (CmpSize == 4) return ComputeCmp<uint32_t, int32_t>(CmpType, Arg1, Arg2);
+ if (CmpSize == 2) return ComputeCmp<uint16_t, int16_t>(CmpType, Arg1, Arg2);
+ if (CmpSize == 1) return ComputeCmp<uint8_t, int8_t>(CmpType, Arg1, Arg2);
+ assert(0 && "unsupported type size");
+ return true;
+}
+
+// As a simplification we use the range of input bytes instead of a set of input
+// bytes.
+struct LabelRange {
+ uint16_t Beg, End; // Range is [Beg, End), thus Beg==End is an empty range.
+
+ LabelRange(uint16_t Beg = 0, uint16_t End = 0) : Beg(Beg), End(End) {}
+
+ static LabelRange Join(LabelRange LR1, LabelRange LR2) {
+ if (LR1.Beg == LR1.End) return LR2;
+ if (LR2.Beg == LR2.End) return LR1;
+ return {std::min(LR1.Beg, LR2.Beg), std::max(LR1.End, LR2.End)};
+ }
+ LabelRange &Join(LabelRange LR) {
+ return *this = Join(*this, LR);
+ }
+ static LabelRange Singleton(const dfsan_label_info *LI) {
+ uint16_t Idx = (uint16_t)(uintptr_t)LI->userdata;
+ assert(Idx > 0);
+ return {(uint16_t)(Idx - 1), Idx};
+ }
+};
+
+std::ostream &operator<<(std::ostream &os, const LabelRange &LR) {
+ return os << "[" << LR.Beg << "," << LR.End << ")";
+}
+
+// For now, very simple: put Size bytes of Data at position Pos.
+struct TraceBasedMutation {
+ size_t Pos;
+ size_t Size;
+ uint64_t Data;
+};
+
+class TraceState {
+ public:
+ TraceState(const Fuzzer::FuzzingOptions &Options, const Unit &CurrentUnit)
+ : Options(Options), CurrentUnit(CurrentUnit) {}
+
+ LabelRange GetLabelRange(dfsan_label L);
+ void DFSanCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
+ uint64_t Arg1, uint64_t Arg2, dfsan_label L1,
+ dfsan_label L2);
+ void TraceCmpCallback(size_t CmpSize, size_t CmpType, uint64_t Arg1,
+ uint64_t Arg2);
+ int TryToAddDesiredData(uint64_t PresentData, uint64_t DesiredData,
+ size_t DataSize);
+
+ void StartTraceRecording() {
+ RecordingTraces = true;
+ Mutations.clear();
+ }
+
+ size_t StopTraceRecording() {
+ RecordingTraces = false;
+ std::random_shuffle(Mutations.begin(), Mutations.end());
+ return Mutations.size();
+ }
+
+ void ApplyTraceBasedMutation(size_t Idx, fuzzer::Unit *U);
+
+ private:
+ bool IsTwoByteData(uint64_t Data) {
+ int64_t Signed = static_cast<int64_t>(Data);
+ Signed >>= 16;
+ return Signed == 0 || Signed == -1L;
+ }
+ bool RecordingTraces = false;
+ std::vector<TraceBasedMutation> Mutations;
+ LabelRange LabelRanges[1 << (sizeof(dfsan_label) * 8)] = {};
+ const Fuzzer::FuzzingOptions &Options;
+ const Unit &CurrentUnit;
+};
+
+LabelRange TraceState::GetLabelRange(dfsan_label L) {
+ LabelRange &LR = LabelRanges[L];
+ if (LR.Beg < LR.End || L == 0)
+ return LR;
+ const dfsan_label_info *LI = dfsan_get_label_info(L);
+ if (LI->l1 || LI->l2)
+ return LR = LabelRange::Join(GetLabelRange(LI->l1), GetLabelRange(LI->l2));
+ return LR = LabelRange::Singleton(LI);
+}
+
+void TraceState::ApplyTraceBasedMutation(size_t Idx, fuzzer::Unit *U) {
+ assert(Idx < Mutations.size());
+ auto &M = Mutations[Idx];
+ if (Options.Verbosity >= 3)
+ std::cerr << "TBM " << M.Pos << " " << M.Size << " " << M.Data << "\n";
+ if (M.Pos + M.Size > U->size()) return;
+ memcpy(U->data() + M.Pos, &M.Data, M.Size);
+}
+
+void TraceState::DFSanCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
+ uint64_t Arg1, uint64_t Arg2, dfsan_label L1,
+ dfsan_label L2) {
+ assert(ReallyHaveDFSan());
+ if (!RecordingTraces) return;
+ if (L1 == 0 && L2 == 0)
+ return; // Not actionable.
+ if (L1 != 0 && L2 != 0)
+ return; // Probably still actionable.
+ bool Res = ComputeCmp(CmpSize, CmpType, Arg1, Arg2);
+ uint64_t Data = L1 ? Arg2 : Arg1;
+ LabelRange LR = L1 ? GetLabelRange(L1) : GetLabelRange(L2);
+
+ for (size_t Pos = LR.Beg; Pos + CmpSize <= LR.End; Pos++) {
+ Mutations.push_back({Pos, CmpSize, Data});
+ Mutations.push_back({Pos, CmpSize, Data + 1});
+ Mutations.push_back({Pos, CmpSize, Data - 1});
+ }
+
+ if (CmpSize > LR.End - LR.Beg)
+ Mutations.push_back({LR.Beg, (unsigned)(LR.End - LR.Beg), Data});
+
+
+ if (Options.Verbosity >= 3)
+ std::cerr << "DFSAN:"
+ << " PC " << std::hex << PC << std::dec
+ << " S " << CmpSize
+ << " T " << CmpType
+ << " A1 " << Arg1 << " A2 " << Arg2 << " R " << Res
+ << " L" << L1
+ << " L" << L2
+ << " R" << LR
+ << " MU " << Mutations.size()
+ << "\n";
+}
+
+int TraceState::TryToAddDesiredData(uint64_t PresentData, uint64_t DesiredData,
+ size_t DataSize) {
+ int Res = 0;
+ const uint8_t *Beg = CurrentUnit.data();
+ const uint8_t *End = Beg + CurrentUnit.size();
+ for (const uint8_t *Cur = Beg; Cur < End; Cur += DataSize) {
+ Cur = (uint8_t *)memmem(Cur, End - Cur, &PresentData, DataSize);
+ if (!Cur)
+ break;
+ // std::cerr << "Cur " << (void*)Cur << "\n";
+ size_t Pos = Cur - Beg;
+ assert(Pos < CurrentUnit.size());
+ Mutations.push_back({Pos, DataSize, DesiredData});
+ Mutations.push_back({Pos, DataSize, DesiredData + 1});
+ Mutations.push_back({Pos, DataSize, DesiredData - 1});
+ Cur += DataSize;
+ Res++;
+ }
+ return Res;
+}
+
+void TraceState::TraceCmpCallback(size_t CmpSize, size_t CmpType, uint64_t Arg1,
+ uint64_t Arg2) {
+ if (!Options.UseTraces) return;
+ int Added = 0;
+ if (Options.Verbosity >= 3)
+ std::cerr << "TraceCmp: " << Arg1 << " " << Arg2 << "\n";
+ Added += TryToAddDesiredData(Arg1, Arg2, CmpSize);
+ Added += TryToAddDesiredData(Arg2, Arg1, CmpSize);
+ if (!Added && CmpSize == 4 && IsTwoByteData(Arg1) && IsTwoByteData(Arg2)) {
+ Added += TryToAddDesiredData(Arg1, Arg2, 2);
+ Added += TryToAddDesiredData(Arg2, Arg1, 2);
+ }
+}
+
+static TraceState *TS;
+
+void Fuzzer::StartTraceRecording() {
+ if (!TS) return;
+ TS->StartTraceRecording();
+}
+
+size_t Fuzzer::StopTraceRecording() {
+ if (!TS) return 0;
+ return TS->StopTraceRecording();
+}
+
+void Fuzzer::ApplyTraceBasedMutation(size_t Idx, Unit *U) {
+ assert(TS);
+ TS->ApplyTraceBasedMutation(Idx, U);
+}
+
+void Fuzzer::InitializeTraceState() {
+ if (!Options.UseTraces && !Options.UseDFSan) return;
+ TS = new TraceState(Options, CurrentUnit);
+ CurrentUnit.resize(Options.MaxLen);
+ // The rest really requires DFSan.
+ if (!ReallyHaveDFSan() || !Options.UseDFSan) return;
+ for (size_t i = 0; i < static_cast<size_t>(Options.MaxLen); i++) {
+ dfsan_label L = dfsan_create_label("input", (void*)(i + 1));
+ // We assume that no one else has called dfsan_create_label before.
+ assert(L == i + 1);
+ dfsan_set_label(L, &CurrentUnit[i], 1);
+ }
+}
+
+} // namespace fuzzer
+
+using fuzzer::TS;
+
+extern "C" {
+void __dfsw___sanitizer_cov_trace_cmp(uint64_t SizeAndType, uint64_t Arg1,
+ uint64_t Arg2, dfsan_label L0,
+ dfsan_label L1, dfsan_label L2) {
+ assert(TS);
+ assert(L0 == 0);
+ uintptr_t PC = reinterpret_cast<uintptr_t>(__builtin_return_address(0));
+ uint64_t CmpSize = (SizeAndType >> 32) / 8;
+ uint64_t Type = (SizeAndType << 32) >> 32;
+ TS->DFSanCmpCallback(PC, CmpSize, Type, Arg1, Arg2, L1, L2);
+}
+
+void dfsan_weak_hook_memcmp(void *caller_pc, const void *s1, const void *s2,
+ size_t n, dfsan_label s1_label,
+ dfsan_label s2_label, dfsan_label n_label) {
+ assert(TS);
+ uintptr_t PC = reinterpret_cast<uintptr_t>(caller_pc);
+ uint64_t S1 = 0, S2 = 0;
+ // Simplification: handle only first 8 bytes.
+ memcpy(&S1, s1, std::min(n, sizeof(S1)));
+ memcpy(&S2, s2, std::min(n, sizeof(S2)));
+ dfsan_label L1 = dfsan_read_label(s1, n);
+ dfsan_label L2 = dfsan_read_label(s2, n);
+ TS->DFSanCmpCallback(PC, n, fuzzer::ICMP_EQ, S1, S2, L1, L2);
+}
+
+void __sanitizer_cov_trace_cmp(uint64_t SizeAndType, uint64_t Arg1,
+ uint64_t Arg2) {
+ if (!TS) return;
+ uint64_t CmpSize = (SizeAndType >> 32) / 8;
+ uint64_t Type = (SizeAndType << 32) >> 32;
+ TS->TraceCmpCallback(CmpSize, Type, Arg1, Arg2);
+}
+
+} // extern "C"
projects / oota-llvm.git / commitdiff