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-rw-r--r--llvm/lib/Fuzzer/CMakeLists.txt2
-rw-r--r--llvm/lib/Fuzzer/FuzzerDriver.cpp3
-rw-r--r--llvm/lib/Fuzzer/FuzzerFlags.def2
-rw-r--r--llvm/lib/Fuzzer/FuzzerInternal.h8
-rw-r--r--llvm/lib/Fuzzer/FuzzerLoop.cpp13
-rw-r--r--llvm/lib/Fuzzer/FuzzerTraceState.cpp70
-rw-r--r--llvm/lib/Fuzzer/FuzzerValueBitMap.h5
-rw-r--r--llvm/lib/Fuzzer/test/CMakeLists.txt3
-rw-r--r--llvm/lib/Fuzzer/test/SingleMemcmpTest.cpp17
-rw-r--r--llvm/lib/Fuzzer/test/SingleStrcmpTest.cpp17
-rw-r--r--llvm/lib/Fuzzer/test/SingleStrncmpTest.cpp17
-rw-r--r--llvm/lib/Fuzzer/test/StrncmpTest.cpp2
-rw-r--r--llvm/lib/Fuzzer/test/value-profile-cmp.test3
-rw-r--r--llvm/lib/Fuzzer/test/value-profile-mem.test4
-rw-r--r--llvm/lib/Fuzzer/test/value-profile-set.test3
15 files changed, 158 insertions, 11 deletions
diff --git a/llvm/lib/Fuzzer/CMakeLists.txt b/llvm/lib/Fuzzer/CMakeLists.txt
index 1829f0586b8..05e05816365 100644
--- a/llvm/lib/Fuzzer/CMakeLists.txt
+++ b/llvm/lib/Fuzzer/CMakeLists.txt
@@ -1,6 +1,6 @@
set(LIBFUZZER_FLAGS_BASE "${CMAKE_CXX_FLAGS}")
# Disable the coverage and sanitizer instrumentation for the fuzzer itself.
-set(CMAKE_CXX_FLAGS "${LIBFUZZER_FLAGS_BASE} -fno-sanitize=all -fno-sanitize-coverage=edge,trace-cmp,indirect-calls,8bit-counters -Werror")
+set(CMAKE_CXX_FLAGS "${LIBFUZZER_FLAGS_BASE} -mpopcnt -fno-sanitize=all -fno-sanitize-coverage=edge,trace-cmp,indirect-calls,8bit-counters -Werror")
if( LLVM_USE_SANITIZE_COVERAGE )
if(NOT "${LLVM_USE_SANITIZER}" STREQUAL "Address")
message(FATAL_ERROR
diff --git a/llvm/lib/Fuzzer/FuzzerDriver.cpp b/llvm/lib/Fuzzer/FuzzerDriver.cpp
index a6db9fa338b..e9913e470fd 100644
--- a/llvm/lib/Fuzzer/FuzzerDriver.cpp
+++ b/llvm/lib/Fuzzer/FuzzerDriver.cpp
@@ -339,6 +339,9 @@ int FuzzerDriver(int *argc, char ***argv, UserCallback Callback) {
Options.TruncateUnits = Flags.truncate_units;
Options.PruneCorpus = Flags.prune_corpus;
+ if (Flags.use_value_profile)
+ EnableValueProfile();
+
unsigned Seed = Flags.seed;
// Initialize Seed.
if (Seed == 0)
diff --git a/llvm/lib/Fuzzer/FuzzerFlags.def b/llvm/lib/Fuzzer/FuzzerFlags.def
index 599ac368634..0b313eb6570 100644
--- a/llvm/lib/Fuzzer/FuzzerFlags.def
+++ b/llvm/lib/Fuzzer/FuzzerFlags.def
@@ -44,6 +44,8 @@ FUZZER_FLAG_INT(use_memcmp, 1,
"Use hints from intercepting memcmp, strcmp, etc")
FUZZER_FLAG_INT(use_memmem, 1,
"Use hints from intercepting memmem, strstr, etc")
+FUZZER_FLAG_INT(use_value_profile, 0,
+ "Experimental. Use value profile to guide fuzzing.")
FUZZER_FLAG_INT(jobs, 0, "Number of jobs to run. If jobs >= 1 we spawn"
" this number of jobs in separate worker processes"
" with stdout/stderr redirected to fuzz-JOB.log.")
diff --git a/llvm/lib/Fuzzer/FuzzerInternal.h b/llvm/lib/Fuzzer/FuzzerInternal.h
index db1e505ac38..940d8365f34 100644
--- a/llvm/lib/Fuzzer/FuzzerInternal.h
+++ b/llvm/lib/Fuzzer/FuzzerInternal.h
@@ -134,6 +134,10 @@ void SleepSeconds(int Seconds);
// See FuzzerTracePC.cpp
size_t PCMapMergeFromCurrent(ValueBitMap &M);
+// See FuzzerTraceState.cpp
+void EnableValueProfile();
+size_t VPMapMergeFromCurrent(ValueBitMap &M);
+
class Random {
public:
Random(unsigned int seed) : R(seed) {}
@@ -356,6 +360,8 @@ public:
CounterBitmap.clear();
PCMap.Reset();
PCMapBits = 0;
+ VPMap.Reset();
+ VPMapBits = 0;
PcBufferPos = 0;
}
@@ -369,6 +375,8 @@ public:
std::vector<uint8_t> CounterBitmap;
ValueBitMap PCMap;
size_t PCMapBits;
+ ValueBitMap VPMap;
+ size_t VPMapBits;
};
Fuzzer(UserCallback CB, MutationDispatcher &MD, FuzzingOptions Options);
diff --git a/llvm/lib/Fuzzer/FuzzerLoop.cpp b/llvm/lib/Fuzzer/FuzzerLoop.cpp
index f90b7092d49..07de3c7c8b9 100644
--- a/llvm/lib/Fuzzer/FuzzerLoop.cpp
+++ b/llvm/lib/Fuzzer/FuzzerLoop.cpp
@@ -122,6 +122,12 @@ class CoverageController {
C->PCMapBits = NewPCMapBits;
}
+ size_t NewVPMapBits = VPMapMergeFromCurrent(C->VPMap);
+ if (NewVPMapBits > C->VPMapBits) {
+ Res = true;
+ C->VPMapBits = NewVPMapBits;
+ }
+
if (EF->__sanitizer_get_coverage_pc_buffer_pos) {
uint64_t NewPcBufferPos = EF->__sanitizer_get_coverage_pc_buffer_pos();
if (NewPcBufferPos > C->PcBufferPos) {
@@ -307,6 +313,8 @@ void Fuzzer::PrintStats(const char *Where, const char *End) {
Printf(" cov: %zd", MaxCoverage.BlockCoverage);
if (MaxCoverage.PCMapBits)
Printf(" path: %zd", MaxCoverage.PCMapBits);
+ if (MaxCoverage.VPMapBits)
+ Printf(" vp: %zd", MaxCoverage.VPMapBits);
if (auto TB = MaxCoverage.CounterBitmapBits)
Printf(" bits: %zd", TB);
if (MaxCoverage.CallerCalleeCoverage)
@@ -520,8 +528,9 @@ std::string Fuzzer::Coverage::DebugString() const {
std::string("Coverage{") + "BlockCoverage=" +
std::to_string(BlockCoverage) + " CallerCalleeCoverage=" +
std::to_string(CallerCalleeCoverage) + " CounterBitmapBits=" +
- std::to_string(CounterBitmapBits) + " PcMapBits=" +
- std::to_string(PCMapBits) + "}";
+ std::to_string(CounterBitmapBits) + " PCMapBits=" +
+ std::to_string(PCMapBits) + " VPMapBits " +
+ std::to_string(VPMapBits) + "}";
return Result;
}
diff --git a/llvm/lib/Fuzzer/FuzzerTraceState.cpp b/llvm/lib/Fuzzer/FuzzerTraceState.cpp
index 6f87fcae5fc..9eae068c354 100644
--- a/llvm/lib/Fuzzer/FuzzerTraceState.cpp
+++ b/llvm/lib/Fuzzer/FuzzerTraceState.cpp
@@ -173,6 +173,7 @@ struct TraceBasedMutation {
static bool RecordingTraces = false;
static bool RecordingMemcmp = false;
static bool RecordingMemmem = false;
+static bool RecordingValueProfile = false;
static bool DoingMyOwnMemmem = false;
struct ScopedDoingMyOwnMemmem {
@@ -529,11 +530,60 @@ static size_t InternalStrnlen(const char *S, size_t MaxLen) {
return Len;
}
+// Value profile.
+// We keep track of various values that affect control flow.
+// These values are inserted into a bit-set-based hash map (ValueBitMap VP).
+// Every new bit in the map is treated as a new coverage.
+//
+// For memcmp/strcmp/etc the interesting value is the length of the common
+// prefix of the parameters.
+// For cmp instructions the interesting value is a XOR of the parameters.
+// The interesting value is mixed up with the PC and is then added to the map.
+static ValueBitMap VP;
+
+void EnableValueProfile() { RecordingValueProfile = true; }
+
+size_t VPMapMergeFromCurrent(ValueBitMap &M) {
+ if (!RecordingValueProfile) return 0;
+ return M.MergeFrom(VP);
+}
+
+static void AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2,
+ size_t n) {
+ if (!n) return;
+ size_t Len = std::min(n, (size_t)32);
+ const char *A1 = reinterpret_cast<const char *>(s1);
+ const char *A2 = reinterpret_cast<const char *>(s2);
+ size_t LastSameByte = 0;
+ for (; LastSameByte < Len; LastSameByte++)
+ if (A1[LastSameByte] != A2[LastSameByte])
+ break;
+ size_t PC = reinterpret_cast<size_t>(caller_pc);
+ VP.AddValue((PC & 4095) | (LastSameByte << 12));
+}
+
+static void AddValueForStrcmp(void *caller_pc, const char *s1, const char *s2,
+ size_t n) {
+ if (!n) return;
+ size_t Len = std::min(n, (size_t)32);
+ size_t LastSameByte = 0;
+ for (; LastSameByte < Len; LastSameByte++)
+ if (s1[LastSameByte] != s2[LastSameByte] || s1[LastSameByte] == 0)
+ break;
+ size_t PC = reinterpret_cast<size_t>(caller_pc);
+ VP.AddValue((PC & 4095) | (LastSameByte << 12));
+}
+
+static void AddValueForCmp(uintptr_t PC, uint64_t Arg1, uint64_t Arg2) {
+ VP.AddValue((PC & 4095) | (__builtin_popcountl(Arg1 ^ Arg2) << 12));
+}
+
} // namespace fuzzer
using fuzzer::TS;
using fuzzer::RecordingTraces;
using fuzzer::RecordingMemcmp;
+using fuzzer::RecordingValueProfile;
extern "C" {
void __dfsw___sanitizer_cov_trace_cmp(uint64_t SizeAndType, uint64_t Arg1,
@@ -597,6 +647,8 @@ void dfsan_weak_hook_strcmp(void *caller_pc, const char *s1, const char *s2,
#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 (RecordingValueProfile)
+ fuzzer::AddValueForMemcmp(caller_pc, s1, s2, n);
if (!RecordingMemcmp) return;
if (result == 0) return; // No reason to mutate.
if (n <= 1) return; // Not interesting.
@@ -606,6 +658,8 @@ void __sanitizer_weak_hook_memcmp(void *caller_pc, const void *s1,
void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1,
const char *s2, size_t n, int result) {
+ if (RecordingValueProfile)
+ fuzzer::AddValueForStrcmp(caller_pc, s1, s2, n);
if (!RecordingMemcmp) return;
if (result == 0) return; // No reason to mutate.
size_t Len1 = fuzzer::InternalStrnlen(s1, n);
@@ -619,6 +673,8 @@ void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1,
void __sanitizer_weak_hook_strcmp(void *caller_pc, const char *s1,
const char *s2, int result) {
+ if (RecordingValueProfile)
+ fuzzer::AddValueForStrcmp(caller_pc, s1, s2, 64);
if (!RecordingMemcmp) return;
if (result == 0) return; // No reason to mutate.
size_t Len1 = strlen(s1);
@@ -656,11 +712,15 @@ void __sanitizer_weak_hook_memmem(void *called_pc, const void *s1, size_t len1,
__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);
+ if (RecordingTraces) {
+ 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);
+ }
+ if (RecordingValueProfile)
+ fuzzer::AddValueForCmp(
+ reinterpret_cast<uintptr_t>(__builtin_return_address(0)), Arg1, Arg2);
}
__attribute__((visibility("default")))
diff --git a/llvm/lib/Fuzzer/FuzzerValueBitMap.h b/llvm/lib/Fuzzer/FuzzerValueBitMap.h
index 41169d66bc0..493afc574cc 100644
--- a/llvm/lib/Fuzzer/FuzzerValueBitMap.h
+++ b/llvm/lib/Fuzzer/FuzzerValueBitMap.h
@@ -32,7 +32,7 @@ struct ValueBitMap {
Map[WordIdx] |= 1UL << BitIdx;
}
- // Merges 'Other' into 'this', clear Other,
+ // Merges 'Other' into 'this', clears 'Other',
// returns the number of set bits in 'this'.
size_t MergeFrom(ValueBitMap &Other) {
uintptr_t Res = 0;
@@ -43,7 +43,8 @@ struct ValueBitMap {
Map[i] = (M |= O);
Other.Map[i] = 0;
}
- Res += __builtin_popcountl(M);
+ if (M)
+ Res += __builtin_popcountl(M);
}
return Res;
}
diff --git a/llvm/lib/Fuzzer/test/CMakeLists.txt b/llvm/lib/Fuzzer/test/CMakeLists.txt
index 2164086b5a7..1d82408d7cb 100644
--- a/llvm/lib/Fuzzer/test/CMakeLists.txt
+++ b/llvm/lib/Fuzzer/test/CMakeLists.txt
@@ -88,6 +88,9 @@ set(Tests
SimpleHashTest
SimpleTest
SimpleThreadedTest
+ SingleMemcmpTest
+ SingleStrcmpTest
+ SingleStrncmpTest
SpamyTest
StrcmpTest
StrncmpTest
diff --git a/llvm/lib/Fuzzer/test/SingleMemcmpTest.cpp b/llvm/lib/Fuzzer/test/SingleMemcmpTest.cpp
new file mode 100644
index 00000000000..c73f68a7ee6
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/SingleMemcmpTest.cpp
@@ -0,0 +1,17 @@
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+
+// Simple test for a fuzzer. The fuzzer must find a particular string.
+#include <cstring>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+ char *S = (char*)Data;
+ if (Size >= 6 && !memcmp(S, "qwerty", 6)) {
+ fprintf(stderr, "BINGO\n");
+ exit(1);
+ }
+ return 0;
+}
diff --git a/llvm/lib/Fuzzer/test/SingleStrcmpTest.cpp b/llvm/lib/Fuzzer/test/SingleStrcmpTest.cpp
new file mode 100644
index 00000000000..73470b527ee
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/SingleStrcmpTest.cpp
@@ -0,0 +1,17 @@
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+
+// Simple test for a fuzzer. The fuzzer must find a particular string.
+#include <cstring>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+ char *S = (char*)Data;
+ if (Size >= 7 && !strcmp(S, "qwerty")) {
+ fprintf(stderr, "BINGO\n");
+ exit(1);
+ }
+ return 0;
+}
diff --git a/llvm/lib/Fuzzer/test/SingleStrncmpTest.cpp b/llvm/lib/Fuzzer/test/SingleStrncmpTest.cpp
new file mode 100644
index 00000000000..dbcc464b0a7
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/SingleStrncmpTest.cpp
@@ -0,0 +1,17 @@
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+
+// Simple test for a fuzzer. The fuzzer must find a particular string.
+#include <cstring>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+ char *S = (char*)Data;
+ if (Size >= 6 && !strncmp(S, "qwerty", 6)) {
+ fprintf(stderr, "BINGO\n");
+ exit(1);
+ }
+ return 0;
+}
diff --git a/llvm/lib/Fuzzer/test/StrncmpTest.cpp b/llvm/lib/Fuzzer/test/StrncmpTest.cpp
index 8575c2682f1..5ffd011dcdf 100644
--- a/llvm/lib/Fuzzer/test/StrncmpTest.cpp
+++ b/llvm/lib/Fuzzer/test/StrncmpTest.cpp
@@ -17,7 +17,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
if (Size >= 8 && strncmp(S, "01234567", 8) == 0) {
if (Size >= 12 && strncmp(S + 8, "ABCD", 4) == 0) {
if (Size >= 14 && strncmp(S + 12, "XY", 2) == 0) {
- if (Size >= 16 && strncmp(S + 14, "KLM", 3) == 0) {
+ if (Size >= 17 && strncmp(S + 14, "KLM", 3) == 0) {
fprintf(stderr, "BINGO\n");
exit(1);
}
diff --git a/llvm/lib/Fuzzer/test/value-profile-cmp.test b/llvm/lib/Fuzzer/test/value-profile-cmp.test
new file mode 100644
index 00000000000..e4059cd82ee
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/value-profile-cmp.test
@@ -0,0 +1,3 @@
+CHECK: BINGO
+RUN: not LLVMFuzzer-SimpleCmpTest -use_value_profile=1 -runs=100000000 2>&1 | FileCheck %s
+
diff --git a/llvm/lib/Fuzzer/test/value-profile-mem.test b/llvm/lib/Fuzzer/test/value-profile-mem.test
new file mode 100644
index 00000000000..2052e879164
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/value-profile-mem.test
@@ -0,0 +1,4 @@
+CHECK: BINGO
+RUN: not LLVMFuzzer-SingleMemcmpTest -use_memcmp=0 -use_value_profile=1 -runs=10000000 2>&1 | FileCheck %s
+RUN: not LLVMFuzzer-SingleStrcmpTest -use_memcmp=0 -use_value_profile=1 -runs=10000000 2>&1 | FileCheck %s
+RUN: not LLVMFuzzer-SingleStrncmpTest -use_memcmp=0 -use_value_profile=1 -runs=10000000 2>&1 | FileCheck %s
diff --git a/llvm/lib/Fuzzer/test/value-profile-set.test b/llvm/lib/Fuzzer/test/value-profile-set.test
new file mode 100644
index 00000000000..300afa9320d
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/value-profile-set.test
@@ -0,0 +1,3 @@
+CHECK: BINGO
+RUN: not LLVMFuzzer-FourIndependentBranchesTest -seed=1 -use_value_profile=1 -runs=100000000 2>&1 | FileCheck %s
+
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