forked from OSchip/llvm-project
617 lines
23 KiB
C++
617 lines
23 KiB
C++
//===- FuzzerTraceState.cpp - Trace-based fuzzer mutator ------------------===//
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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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// This file implements a mutation algorithm based on instruction traces and
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// on taint analysis feedback from DFSan.
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//
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// Instruction traces are special hooks inserted by the compiler around
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// interesting instructions. Currently supported traces:
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// * __sanitizer_cov_trace_cmp -- inserted before every ICMP instruction,
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// receives the type, size and arguments of ICMP.
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//
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// Every time a traced event is intercepted we analyse the data involved
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// in the event and suggest a mutation for future executions.
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// For example if 4 bytes of data that derive from input bytes {4,5,6,7}
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// are compared with a constant 12345,
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// we try to insert 12345, 12344, 12346 into bytes
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// {4,5,6,7} of the next fuzzed inputs.
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//
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// The fuzzer can work only with the traces, or with both traces and DFSan.
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//
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// DataFlowSanitizer (DFSan) is a tool for
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// generalised dynamic data flow (taint) analysis:
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// http://clang.llvm.org/docs/DataFlowSanitizer.html .
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//
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// The approach with DFSan-based fuzzing has some similarity to
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// "Taint-based Directed Whitebox Fuzzing"
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// by Vijay Ganesh & Tim Leek & Martin Rinard:
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// http://dspace.mit.edu/openaccess-disseminate/1721.1/59320,
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// but it uses a full blown LLVM IR taint analysis and separate instrumentation
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// to analyze all of the "attack points" at once.
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//
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// Workflow with DFSan:
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// * lib/Fuzzer/Fuzzer*.cpp is compiled w/o any instrumentation.
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// * The code under test is compiled with DFSan *and* with instruction traces.
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// * Every call to HOOK(a,b) is replaced by DFSan with
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// __dfsw_HOOK(a, b, label(a), label(b)) so that __dfsw_HOOK
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// gets all the taint labels for the arguments.
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// * At the Fuzzer startup we assign a unique DFSan label
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// to every byte of the input string (Fuzzer::CurrentUnitData) so that
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// for any chunk of data we know which input bytes it has derived from.
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// * The __dfsw_* functions (implemented in this file) record the
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// parameters (i.e. the application data and the corresponding taint labels)
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// in a global state.
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//
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// Parts of this code will not function when DFSan is not linked in.
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// Instead of using ifdefs and thus requiring a separate build of lib/Fuzzer
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// we redeclare the dfsan_* interface functions as weak and check if they
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// are nullptr before calling.
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// If this approach proves to be useful we may add attribute(weak) to the
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// dfsan declarations in dfsan_interface.h
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//
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// This module is in the "proof of concept" stage.
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// It is capable of solving only the simplest puzzles
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// like test/dfsan/DFSanSimpleCmpTest.cpp.
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//===----------------------------------------------------------------------===//
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/* Example of manual usage (-fsanitize=dataflow is optional):
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(
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cd $LLVM/lib/Fuzzer/
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clang -fPIC -c -g -O2 -std=c++11 Fuzzer*.cpp
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clang++ -O0 -std=c++11 -fsanitize-coverage=edge,trace-cmp \
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-fsanitize=dataflow \
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test/SimpleCmpTest.cpp Fuzzer*.o
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./a.out -use_traces=1
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)
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*/
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#include "FuzzerDFSan.h"
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#include "FuzzerInternal.h"
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#include <algorithm>
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#include <cstring>
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#include <thread>
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#include <map>
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#if !LLVM_FUZZER_SUPPORTS_DFSAN
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// Stubs for dfsan for platforms where dfsan does not exist and weak
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// functions don't work.
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extern "C" {
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dfsan_label dfsan_create_label(const char *desc, void *userdata) { return 0; }
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void dfsan_set_label(dfsan_label label, void *addr, size_t size) {}
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void dfsan_add_label(dfsan_label label, void *addr, size_t size) {}
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const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label) {
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return nullptr;
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}
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dfsan_label dfsan_read_label(const void *addr, size_t size) { return 0; }
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} // extern "C"
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#endif // !LLVM_FUZZER_SUPPORTS_DFSAN
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namespace fuzzer {
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// These values are copied from include/llvm/IR/InstrTypes.h.
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// We do not include the LLVM headers here to remain independent.
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// If these values ever change, an assertion in ComputeCmp will fail.
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enum Predicate {
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ICMP_EQ = 32, ///< equal
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ICMP_NE = 33, ///< not equal
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ICMP_UGT = 34, ///< unsigned greater than
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ICMP_UGE = 35, ///< unsigned greater or equal
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ICMP_ULT = 36, ///< unsigned less than
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ICMP_ULE = 37, ///< unsigned less or equal
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ICMP_SGT = 38, ///< signed greater than
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ICMP_SGE = 39, ///< signed greater or equal
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ICMP_SLT = 40, ///< signed less than
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ICMP_SLE = 41, ///< signed less or equal
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};
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template <class U, class S>
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bool ComputeCmp(size_t CmpType, U Arg1, U Arg2) {
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switch(CmpType) {
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case ICMP_EQ : return Arg1 == Arg2;
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case ICMP_NE : return Arg1 != Arg2;
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case ICMP_UGT: return Arg1 > Arg2;
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case ICMP_UGE: return Arg1 >= Arg2;
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case ICMP_ULT: return Arg1 < Arg2;
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case ICMP_ULE: return Arg1 <= Arg2;
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case ICMP_SGT: return (S)Arg1 > (S)Arg2;
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case ICMP_SGE: return (S)Arg1 >= (S)Arg2;
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case ICMP_SLT: return (S)Arg1 < (S)Arg2;
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case ICMP_SLE: return (S)Arg1 <= (S)Arg2;
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default: assert(0 && "unsupported CmpType");
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}
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return false;
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}
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static bool ComputeCmp(size_t CmpSize, size_t CmpType, uint64_t Arg1,
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uint64_t Arg2) {
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if (CmpSize == 8) return ComputeCmp<uint64_t, int64_t>(CmpType, Arg1, Arg2);
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if (CmpSize == 4) return ComputeCmp<uint32_t, int32_t>(CmpType, Arg1, Arg2);
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if (CmpSize == 2) return ComputeCmp<uint16_t, int16_t>(CmpType, Arg1, Arg2);
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if (CmpSize == 1) return ComputeCmp<uint8_t, int8_t>(CmpType, Arg1, Arg2);
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// Other size, ==
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if (CmpType == ICMP_EQ) return Arg1 == Arg2;
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// assert(0 && "unsupported cmp and type size combination");
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return true;
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}
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// As a simplification we use the range of input bytes instead of a set of input
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// bytes.
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struct LabelRange {
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uint16_t Beg, End; // Range is [Beg, End), thus Beg==End is an empty range.
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LabelRange(uint16_t Beg = 0, uint16_t End = 0) : Beg(Beg), End(End) {}
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static LabelRange Join(LabelRange LR1, LabelRange LR2) {
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if (LR1.Beg == LR1.End) return LR2;
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if (LR2.Beg == LR2.End) return LR1;
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return {std::min(LR1.Beg, LR2.Beg), std::max(LR1.End, LR2.End)};
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}
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LabelRange &Join(LabelRange LR) {
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return *this = Join(*this, LR);
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}
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static LabelRange Singleton(const dfsan_label_info *LI) {
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uint16_t Idx = (uint16_t)(uintptr_t)LI->userdata;
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assert(Idx > 0);
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return {(uint16_t)(Idx - 1), Idx};
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}
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};
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// For now, very simple: put Size bytes of Data at position Pos.
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struct TraceBasedMutation {
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static const size_t kMaxSize = 28;
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uint32_t Pos : 24;
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uint32_t Size : 8;
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uint8_t Data[kMaxSize];
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};
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const size_t TraceBasedMutation::kMaxSize;
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// Declared as static globals for faster checks inside the hooks.
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static bool RecordingTraces = false;
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static bool RecordingMemcmp = false;
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class TraceState {
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public:
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TraceState(UserSuppliedFuzzer &USF, const Fuzzer::FuzzingOptions &Options,
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uint8_t **CurrentUnitData, size_t *CurrentUnitSize)
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: USF(USF), Options(Options), CurrentUnitData(CurrentUnitData),
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CurrentUnitSize(CurrentUnitSize) {
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// Current trace collection is not thread-friendly and it probably
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// does not have to be such, but at least we should not crash in presence
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// of threads. So, just ignore all traces coming from all threads but one.
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IsMyThread = true;
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}
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LabelRange GetLabelRange(dfsan_label L);
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void DFSanCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
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uint64_t Arg1, uint64_t Arg2, dfsan_label L1,
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dfsan_label L2);
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void DFSanMemcmpCallback(size_t CmpSize, const uint8_t *Data1,
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const uint8_t *Data2, dfsan_label L1,
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dfsan_label L2);
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void DFSanSwitchCallback(uint64_t PC, size_t ValSizeInBits, uint64_t Val,
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size_t NumCases, uint64_t *Cases, dfsan_label L);
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void TraceCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
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uint64_t Arg1, uint64_t Arg2);
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void TraceMemcmpCallback(size_t CmpSize, const uint8_t *Data1,
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const uint8_t *Data2);
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void TraceSwitchCallback(uintptr_t PC, size_t ValSizeInBits, uint64_t Val,
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size_t NumCases, uint64_t *Cases);
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int TryToAddDesiredData(uint64_t PresentData, uint64_t DesiredData,
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size_t DataSize);
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int TryToAddDesiredData(const uint8_t *PresentData,
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const uint8_t *DesiredData, size_t DataSize);
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void StartTraceRecording() {
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if (!Options.UseTraces && !Options.UseMemcmp) return;
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RecordingTraces = Options.UseTraces;
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RecordingMemcmp = Options.UseMemcmp;
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NumMutations = 0;
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USF.GetMD().ClearAutoDictionary();
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}
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void StopTraceRecording() {
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if (!RecordingTraces && !RecordingMemcmp) return;
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RecordingTraces = false;
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RecordingMemcmp = false;
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for (size_t i = 0; i < NumMutations; i++) {
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auto &M = Mutations[i];
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Unit U(M.Data, M.Data + M.Size);
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if (Options.Verbosity >= 2) {
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AutoDictUnitCounts[U]++;
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AutoDictAdds++;
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if ((AutoDictAdds & (AutoDictAdds - 1)) == 0) {
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typedef std::pair<size_t, Unit> CU;
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std::vector<CU> CountedUnits;
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for (auto &I : AutoDictUnitCounts)
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CountedUnits.push_back(std::make_pair(I.second, I.first));
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std::sort(CountedUnits.begin(), CountedUnits.end(),
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[](const CU &a, const CU &b) { return a.first > b.first; });
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Printf("AutoDict:\n");
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for (auto &I : CountedUnits) {
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Printf(" %zd ", I.first);
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PrintASCII(I.second);
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Printf("\n");
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}
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}
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}
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USF.GetMD().AddWordToAutoDictionary(U, M.Pos);
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}
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}
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void AddMutation(uint32_t Pos, uint32_t Size, const uint8_t *Data) {
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if (NumMutations >= kMaxMutations) return;
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assert(Size <= TraceBasedMutation::kMaxSize);
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auto &M = Mutations[NumMutations++];
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M.Pos = Pos;
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M.Size = Size;
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memcpy(M.Data, Data, Size);
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}
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void AddMutation(uint32_t Pos, uint32_t Size, uint64_t Data) {
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assert(Size <= sizeof(Data));
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AddMutation(Pos, Size, reinterpret_cast<uint8_t*>(&Data));
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}
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private:
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bool IsTwoByteData(uint64_t Data) {
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int64_t Signed = static_cast<int64_t>(Data);
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Signed >>= 16;
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return Signed == 0 || Signed == -1L;
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}
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static const size_t kMaxMutations = 1 << 16;
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size_t NumMutations;
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TraceBasedMutation Mutations[kMaxMutations];
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LabelRange LabelRanges[1 << (sizeof(dfsan_label) * 8)];
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UserSuppliedFuzzer &USF;
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const Fuzzer::FuzzingOptions &Options;
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uint8_t **CurrentUnitData;
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size_t *CurrentUnitSize;
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std::map<Unit, size_t> AutoDictUnitCounts;
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size_t AutoDictAdds = 0;
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static thread_local bool IsMyThread;
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};
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thread_local bool TraceState::IsMyThread;
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LabelRange TraceState::GetLabelRange(dfsan_label L) {
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LabelRange &LR = LabelRanges[L];
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if (LR.Beg < LR.End || L == 0)
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return LR;
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const dfsan_label_info *LI = dfsan_get_label_info(L);
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if (LI->l1 || LI->l2)
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return LR = LabelRange::Join(GetLabelRange(LI->l1), GetLabelRange(LI->l2));
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return LR = LabelRange::Singleton(LI);
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}
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void TraceState::DFSanCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
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uint64_t Arg1, uint64_t Arg2, dfsan_label L1,
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dfsan_label L2) {
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assert(ReallyHaveDFSan());
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if (!RecordingTraces || !IsMyThread) return;
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if (L1 == 0 && L2 == 0)
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return; // Not actionable.
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if (L1 != 0 && L2 != 0)
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return; // Probably still actionable.
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bool Res = ComputeCmp(CmpSize, CmpType, Arg1, Arg2);
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uint64_t Data = L1 ? Arg2 : Arg1;
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LabelRange LR = L1 ? GetLabelRange(L1) : GetLabelRange(L2);
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for (size_t Pos = LR.Beg; Pos + CmpSize <= LR.End; Pos++) {
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AddMutation(Pos, CmpSize, Data);
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AddMutation(Pos, CmpSize, Data + 1);
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AddMutation(Pos, CmpSize, Data - 1);
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}
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if (CmpSize > LR.End - LR.Beg)
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AddMutation(LR.Beg, (unsigned)(LR.End - LR.Beg), Data);
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if (Options.Verbosity >= 3)
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Printf("DFSanCmpCallback: PC %lx S %zd T %zd A1 %llx A2 %llx R %d L1 %d L2 "
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"%d MU %zd\n",
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PC, CmpSize, CmpType, Arg1, Arg2, Res, L1, L2, NumMutations);
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}
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void TraceState::DFSanMemcmpCallback(size_t CmpSize, const uint8_t *Data1,
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const uint8_t *Data2, dfsan_label L1,
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dfsan_label L2) {
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assert(ReallyHaveDFSan());
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if (!RecordingMemcmp || !IsMyThread) return;
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if (L1 == 0 && L2 == 0)
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return; // Not actionable.
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if (L1 != 0 && L2 != 0)
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return; // Probably still actionable.
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const uint8_t *Data = L1 ? Data2 : Data1;
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LabelRange LR = L1 ? GetLabelRange(L1) : GetLabelRange(L2);
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for (size_t Pos = LR.Beg; Pos + CmpSize <= LR.End; Pos++) {
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AddMutation(Pos, CmpSize, Data);
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if (Options.Verbosity >= 3)
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Printf("DFSanMemcmpCallback: Pos %d Size %d\n", Pos, CmpSize);
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}
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}
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void TraceState::DFSanSwitchCallback(uint64_t PC, size_t ValSizeInBits,
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uint64_t Val, size_t NumCases,
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uint64_t *Cases, dfsan_label L) {
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assert(ReallyHaveDFSan());
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if (!RecordingTraces || !IsMyThread) return;
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if (!L) return; // Not actionable.
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LabelRange LR = GetLabelRange(L);
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size_t ValSize = ValSizeInBits / 8;
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bool TryShort = IsTwoByteData(Val);
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for (size_t i = 0; i < NumCases; i++)
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TryShort &= IsTwoByteData(Cases[i]);
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for (size_t Pos = LR.Beg; Pos + ValSize <= LR.End; Pos++)
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for (size_t i = 0; i < NumCases; i++)
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AddMutation(Pos, ValSize, Cases[i]);
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if (TryShort)
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for (size_t Pos = LR.Beg; Pos + 2 <= LR.End; Pos++)
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for (size_t i = 0; i < NumCases; i++)
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AddMutation(Pos, 2, Cases[i]);
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if (Options.Verbosity >= 3)
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Printf("DFSanSwitchCallback: PC %lx Val %zd SZ %zd # %zd L %d: {%d, %d} "
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"TryShort %d\n",
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PC, Val, ValSize, NumCases, L, LR.Beg, LR.End, TryShort);
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}
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int TraceState::TryToAddDesiredData(uint64_t PresentData, uint64_t DesiredData,
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size_t DataSize) {
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int Res = 0;
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const uint8_t *Beg = *CurrentUnitData;
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const uint8_t *End = Beg + *CurrentUnitSize;
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for (const uint8_t *Cur = Beg; Cur < End; Cur++) {
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Cur = (uint8_t *)memmem(Cur, End - Cur, &PresentData, DataSize);
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if (!Cur)
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break;
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size_t Pos = Cur - Beg;
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assert(Pos < *CurrentUnitSize);
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AddMutation(Pos, DataSize, DesiredData);
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AddMutation(Pos, DataSize, DesiredData + 1);
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AddMutation(Pos, DataSize, DesiredData - 1);
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Res++;
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}
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return Res;
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}
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int TraceState::TryToAddDesiredData(const uint8_t *PresentData,
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const uint8_t *DesiredData,
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size_t DataSize) {
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int Res = 0;
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const uint8_t *Beg = *CurrentUnitData;
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const uint8_t *End = Beg + *CurrentUnitSize;
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for (const uint8_t *Cur = Beg; Cur < End; Cur++) {
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Cur = (uint8_t *)memmem(Cur, End - Cur, PresentData, DataSize);
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if (!Cur)
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break;
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size_t Pos = Cur - Beg;
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assert(Pos < *CurrentUnitSize);
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AddMutation(Pos, DataSize, DesiredData);
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Res++;
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}
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return Res;
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}
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void TraceState::TraceCmpCallback(uintptr_t PC, size_t CmpSize, size_t CmpType,
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uint64_t Arg1, uint64_t Arg2) {
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if (!RecordingTraces || !IsMyThread) return;
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if ((CmpType == ICMP_EQ || CmpType == ICMP_NE) && Arg1 == Arg2)
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return; // No reason to mutate.
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int Added = 0;
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Added += TryToAddDesiredData(Arg1, Arg2, CmpSize);
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Added += TryToAddDesiredData(Arg2, Arg1, CmpSize);
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if (!Added && CmpSize == 4 && IsTwoByteData(Arg1) && IsTwoByteData(Arg2)) {
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Added += TryToAddDesiredData(Arg1, Arg2, 2);
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Added += TryToAddDesiredData(Arg2, Arg1, 2);
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}
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if (Options.Verbosity >= 3 && Added)
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Printf("TraceCmp %zd/%zd: %p %zd %zd\n", CmpSize, CmpType, PC, Arg1, Arg2);
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}
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void TraceState::TraceMemcmpCallback(size_t CmpSize, const uint8_t *Data1,
|
|
const uint8_t *Data2) {
|
|
if (!RecordingMemcmp || !IsMyThread) return;
|
|
CmpSize = std::min(CmpSize, TraceBasedMutation::kMaxSize);
|
|
int Added2 = TryToAddDesiredData(Data1, Data2, CmpSize);
|
|
int Added1 = TryToAddDesiredData(Data2, Data1, CmpSize);
|
|
if ((Added1 || Added2) && Options.Verbosity >= 3) {
|
|
Printf("MemCmp Added %d%d: ", Added1, Added2);
|
|
if (Added1) PrintASCII(Data1, CmpSize);
|
|
if (Added2) PrintASCII(Data2, CmpSize);
|
|
Printf("\n");
|
|
}
|
|
}
|
|
|
|
void TraceState::TraceSwitchCallback(uintptr_t PC, size_t ValSizeInBits,
|
|
uint64_t Val, size_t NumCases,
|
|
uint64_t *Cases) {
|
|
if (!RecordingTraces || !IsMyThread) return;
|
|
size_t ValSize = ValSizeInBits / 8;
|
|
bool TryShort = IsTwoByteData(Val);
|
|
for (size_t i = 0; i < NumCases; i++)
|
|
TryShort &= IsTwoByteData(Cases[i]);
|
|
|
|
if (Options.Verbosity >= 3)
|
|
Printf("TraceSwitch: %p %zd # %zd; TryShort %d\n", PC, Val, NumCases,
|
|
TryShort);
|
|
|
|
for (size_t i = 0; i < NumCases; i++) {
|
|
TryToAddDesiredData(Val, Cases[i], ValSize);
|
|
if (TryShort)
|
|
TryToAddDesiredData(Val, Cases[i], 2);
|
|
}
|
|
}
|
|
|
|
static TraceState *TS;
|
|
|
|
void Fuzzer::StartTraceRecording() {
|
|
if (!TS) return;
|
|
TS->StartTraceRecording();
|
|
}
|
|
|
|
void Fuzzer::StopTraceRecording() {
|
|
if (!TS) return;
|
|
TS->StopTraceRecording();
|
|
}
|
|
|
|
void Fuzzer::AssignTaintLabels(uint8_t *Data, size_t Size) {
|
|
if (!Options.UseTraces && !Options.UseMemcmp) return;
|
|
if (!ReallyHaveDFSan()) return;
|
|
for (size_t i = 0; i < Size; i++)
|
|
dfsan_set_label(i + 1, &Data[i], 1);
|
|
}
|
|
|
|
void Fuzzer::InitializeTraceState() {
|
|
if (!Options.UseTraces && !Options.UseMemcmp) return;
|
|
TS = new TraceState(USF, Options, &CurrentUnitData, &CurrentUnitSize);
|
|
if (ReallyHaveDFSan()) {
|
|
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.
|
|
if (L != i + 1) {
|
|
Printf("DFSan labels are not starting from 1, exiting\n");
|
|
exit(1);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static size_t InternalStrnlen(const char *S, size_t MaxLen) {
|
|
size_t Len = 0;
|
|
for (; Len < MaxLen && S[Len]; Len++) {}
|
|
return Len;
|
|
}
|
|
|
|
} // namespace fuzzer
|
|
|
|
using fuzzer::TS;
|
|
using fuzzer::RecordingTraces;
|
|
using fuzzer::RecordingMemcmp;
|
|
|
|
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) {
|
|
if (!RecordingTraces) return;
|
|
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 __dfsw___sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases,
|
|
dfsan_label L1, dfsan_label L2) {
|
|
if (!RecordingTraces) return;
|
|
uintptr_t PC = reinterpret_cast<uintptr_t>(__builtin_return_address(0));
|
|
TS->DFSanSwitchCallback(PC, Cases[1], Val, Cases[0], Cases+2, L1);
|
|
}
|
|
|
|
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) {
|
|
if (!RecordingMemcmp) return;
|
|
dfsan_label L1 = dfsan_read_label(s1, n);
|
|
dfsan_label L2 = dfsan_read_label(s2, n);
|
|
TS->DFSanMemcmpCallback(n, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2), L1, L2);
|
|
}
|
|
|
|
void dfsan_weak_hook_strncmp(void *caller_pc, const char *s1, const char *s2,
|
|
size_t n, dfsan_label s1_label,
|
|
dfsan_label s2_label, dfsan_label n_label) {
|
|
if (!RecordingMemcmp) return;
|
|
n = std::min(n, fuzzer::InternalStrnlen(s1, n));
|
|
n = std::min(n, fuzzer::InternalStrnlen(s2, n));
|
|
dfsan_label L1 = dfsan_read_label(s1, n);
|
|
dfsan_label L2 = dfsan_read_label(s2, n);
|
|
TS->DFSanMemcmpCallback(n, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2), L1, L2);
|
|
}
|
|
|
|
void dfsan_weak_hook_strcmp(void *caller_pc, const char *s1, const char *s2,
|
|
dfsan_label s1_label, dfsan_label s2_label) {
|
|
if (!RecordingMemcmp) return;
|
|
size_t Len1 = strlen(s1);
|
|
size_t Len2 = strlen(s2);
|
|
size_t N = std::min(Len1, Len2);
|
|
if (N <= 1) return; // Not interesting.
|
|
dfsan_label L1 = dfsan_read_label(s1, Len1);
|
|
dfsan_label L2 = dfsan_read_label(s2, Len2);
|
|
TS->DFSanMemcmpCallback(N, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2), L1, L2);
|
|
}
|
|
|
|
// We may need to avoid defining weak hooks to stay compatible with older clang.
|
|
#ifndef LLVM_FUZZER_DEFINES_SANITIZER_WEAK_HOOOKS
|
|
# define LLVM_FUZZER_DEFINES_SANITIZER_WEAK_HOOOKS 1
|
|
#endif
|
|
|
|
#if LLVM_FUZZER_DEFINES_SANITIZER_WEAK_HOOOKS
|
|
void __sanitizer_weak_hook_memcmp(void *caller_pc, const void *s1,
|
|
const void *s2, size_t n, int result) {
|
|
if (!RecordingMemcmp) return;
|
|
if (result == 0) return; // No reason to mutate.
|
|
if (n <= 1) return; // Not interesting.
|
|
TS->TraceMemcmpCallback(n, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2));
|
|
}
|
|
|
|
void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1,
|
|
const char *s2, size_t n, int result) {
|
|
if (!RecordingMemcmp) return;
|
|
if (result == 0) return; // No reason to mutate.
|
|
size_t Len1 = fuzzer::InternalStrnlen(s1, n);
|
|
size_t Len2 = fuzzer::InternalStrnlen(s2, n);
|
|
n = std::min(n, Len1);
|
|
n = std::min(n, Len2);
|
|
if (n <= 1) return; // Not interesting.
|
|
TS->TraceMemcmpCallback(n, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2));
|
|
}
|
|
|
|
void __sanitizer_weak_hook_strcmp(void *caller_pc, const char *s1,
|
|
const char *s2, int result) {
|
|
if (!RecordingMemcmp) return;
|
|
if (result == 0) return; // No reason to mutate.
|
|
size_t Len1 = strlen(s1);
|
|
size_t Len2 = strlen(s2);
|
|
size_t N = std::min(Len1, Len2);
|
|
if (N <= 1) return; // Not interesting.
|
|
TS->TraceMemcmpCallback(N, reinterpret_cast<const uint8_t *>(s1),
|
|
reinterpret_cast<const uint8_t *>(s2));
|
|
}
|
|
|
|
#endif // LLVM_FUZZER_DEFINES_SANITIZER_WEAK_HOOOKS
|
|
|
|
__attribute__((visibility("default")))
|
|
void __sanitizer_cov_trace_cmp(uint64_t SizeAndType, uint64_t Arg1,
|
|
uint64_t Arg2) {
|
|
if (!RecordingTraces) return;
|
|
uintptr_t PC = reinterpret_cast<uintptr_t>(__builtin_return_address(0));
|
|
uint64_t CmpSize = (SizeAndType >> 32) / 8;
|
|
uint64_t Type = (SizeAndType << 32) >> 32;
|
|
TS->TraceCmpCallback(PC, CmpSize, Type, Arg1, Arg2);
|
|
}
|
|
|
|
__attribute__((visibility("default")))
|
|
void __sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases) {
|
|
if (!RecordingTraces) return;
|
|
uintptr_t PC = reinterpret_cast<uintptr_t>(__builtin_return_address(0));
|
|
TS->TraceSwitchCallback(PC, Cases[1], Val, Cases[0], Cases + 2);
|
|
}
|
|
|
|
} // extern "C"
|