[llvm] r299167 - [libFuzzer] make sure we don't execute libFuzzer's mem* and str* hooks while calling mem*/str* inside libFuzzer itself

[Kostya Serebryany via llvm-commits]

Author: kcc
Date: Thu Mar 30 21:21:28 2017
New Revision: 299167

URL: http://llvm.org/viewvc/llvm-project?rev=299167&view=rev
Log:
[libFuzzer] make sure we don't execute libFuzzer's mem* and str* hooks while calling mem*/str* inside libFuzzer itself

Modified:
    llvm/trunk/lib/Fuzzer/FuzzerDefs.h
    llvm/trunk/lib/Fuzzer/FuzzerDictionary.h
    llvm/trunk/lib/Fuzzer/FuzzerMutate.cpp
    llvm/trunk/lib/Fuzzer/FuzzerTracePC.h
    llvm/trunk/lib/Fuzzer/FuzzerTraceState.cpp

Modified: llvm/trunk/lib/Fuzzer/FuzzerDefs.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Fuzzer/FuzzerDefs.h?rev=299167&r1=299166&r2=299167&view=diff
==============================================================================
--- llvm/trunk/lib/Fuzzer/FuzzerDefs.h (original)
+++ llvm/trunk/lib/Fuzzer/FuzzerDefs.h Thu Mar 30 21:21:28 2017
@@ -96,9 +96,10 @@ typedef int (*UserCallback)(const uint8_
 
 int FuzzerDriver(int *argc, char ***argv, UserCallback Callback);
 
-struct ScopedDoingMyOwnMemmem {
-  ScopedDoingMyOwnMemmem();
-  ~ScopedDoingMyOwnMemmem();
+struct ScopedDoingMyOwnMemOrStr {
+  ScopedDoingMyOwnMemOrStr() { DoingMyOwnMemOrStr++; }
+  ~ScopedDoingMyOwnMemOrStr() { DoingMyOwnMemOrStr--; }
+  static int DoingMyOwnMemOrStr;
 };
 
 inline uint8_t  Bswap(uint8_t x)  { return x; }

Modified: llvm/trunk/lib/Fuzzer/FuzzerDictionary.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Fuzzer/FuzzerDictionary.h?rev=299167&r1=299166&r2=299167&view=diff
==============================================================================
--- llvm/trunk/lib/Fuzzer/FuzzerDictionary.h (original)
+++ llvm/trunk/lib/Fuzzer/FuzzerDictionary.h Thu Mar 30 21:21:28 2017
@@ -33,10 +33,12 @@ public:
   }
 
   bool operator==(const FixedWord<kMaxSize> &w) const {
+    ScopedDoingMyOwnMemOrStr scoped_doing_my_own_mem_os_str;
     return Size == w.Size && 0 == memcmp(Data, w.Data, Size);
   }
 
   bool operator<(const FixedWord<kMaxSize> &w) const {
+    ScopedDoingMyOwnMemOrStr scoped_doing_my_own_mem_os_str;
     if (Size != w.Size)
       return Size < w.Size;
     return memcmp(Data, w.Data, Size) < 0;

Modified: llvm/trunk/lib/Fuzzer/FuzzerMutate.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Fuzzer/FuzzerMutate.cpp?rev=299167&r1=299166&r2=299167&view=diff
==============================================================================
--- llvm/trunk/lib/Fuzzer/FuzzerMutate.cpp (original)
+++ llvm/trunk/lib/Fuzzer/FuzzerMutate.cpp Thu Mar 30 21:21:28 2017
@@ -202,7 +202,7 @@ DictionaryEntry MutationDispatcher::Make
     const void *Arg1Mutation, const void *Arg2Mutation,
     size_t ArgSize, const uint8_t *Data,
     size_t Size) {
-  ScopedDoingMyOwnMemmem scoped_doing_my_own_memmem;
+  ScopedDoingMyOwnMemOrStr scoped_doing_my_own_mem_os_str;
   bool HandleFirst = Rand.RandBool();
   const void *ExistingBytes, *DesiredBytes;
   Word W;

Modified: llvm/trunk/lib/Fuzzer/FuzzerTracePC.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Fuzzer/FuzzerTracePC.h?rev=299167&r1=299166&r2=299167&view=diff
==============================================================================
--- llvm/trunk/lib/Fuzzer/FuzzerTracePC.h (original)
+++ llvm/trunk/lib/Fuzzer/FuzzerTracePC.h Thu Mar 30 21:21:28 2017
@@ -34,7 +34,7 @@ struct TableOfRecentCompares {
     T A, B;
   };
   ATTRIBUTE_NO_SANITIZE_ALL
-  void Insert(size_t Idx, T Arg1, T Arg2) {
+  void Insert(size_t Idx, const T &Arg1, const T &Arg2) {
     Idx = Idx % kSize;
     Table[Idx].A = Arg1;
     Table[Idx].B = Arg2;

Modified: llvm/trunk/lib/Fuzzer/FuzzerTraceState.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Fuzzer/FuzzerTraceState.cpp?rev=299167&r1=299166&r2=299167&view=diff
==============================================================================
--- llvm/trunk/lib/Fuzzer/FuzzerTraceState.cpp (original)
+++ llvm/trunk/lib/Fuzzer/FuzzerTraceState.cpp Thu Mar 30 21:21:28 2017
@@ -24,10 +24,8 @@ namespace fuzzer {
 
 // Declared as static globals for faster checks inside the hooks.
 static bool RecordingMemmem = false;
-static bool DoingMyOwnMemmem = false;
 
-ScopedDoingMyOwnMemmem::ScopedDoingMyOwnMemmem() { DoingMyOwnMemmem = true; }
-ScopedDoingMyOwnMemmem::~ScopedDoingMyOwnMemmem() { DoingMyOwnMemmem = false; }
+int ScopedDoingMyOwnMemOrStr::DoingMyOwnMemOrStr;
 
 class TraceState {
 public:
@@ -114,6 +112,7 @@ extern "C" {
 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
 void __sanitizer_weak_hook_memcmp(void *caller_pc, const void *s1,
                                   const void *s2, size_t n, int result) {
+  if (fuzzer::ScopedDoingMyOwnMemOrStr::DoingMyOwnMemOrStr) return;
   if (result == 0) return;  // No reason to mutate.
   if (n <= 1) return;  // Not interesting.
   fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n, /*StopAtZero*/false);
@@ -122,6 +121,7 @@ void __sanitizer_weak_hook_memcmp(void *
 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
 void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1,
                                    const char *s2, size_t n, int result) {
+  if (fuzzer::ScopedDoingMyOwnMemOrStr::DoingMyOwnMemOrStr) return;
   if (result == 0) return;  // No reason to mutate.
   size_t Len1 = fuzzer::InternalStrnlen(s1, n);
   size_t Len2 = fuzzer::InternalStrnlen(s2, n);
@@ -135,6 +135,7 @@ void __sanitizer_weak_hook_strncmp(void
 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
 void __sanitizer_weak_hook_strcmp(void *caller_pc, const char *s1,
                                    const char *s2, int result) {
+  if (fuzzer::ScopedDoingMyOwnMemOrStr::DoingMyOwnMemOrStr) return;
   if (result == 0) return;  // No reason to mutate.
   size_t N = fuzzer::InternalStrnlen2(s1, s2);
   if (N <= 1) return;  // Not interesting.
@@ -144,31 +145,35 @@ void __sanitizer_weak_hook_strcmp(void *
 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
 void __sanitizer_weak_hook_strncasecmp(void *called_pc, const char *s1,
                                        const char *s2, size_t n, int result) {
+  if (fuzzer::ScopedDoingMyOwnMemOrStr::DoingMyOwnMemOrStr) return;
   return __sanitizer_weak_hook_strncmp(called_pc, s1, s2, n, result);
 }
 
 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
 void __sanitizer_weak_hook_strcasecmp(void *called_pc, const char *s1,
                                       const char *s2, int result) {
+  if (fuzzer::ScopedDoingMyOwnMemOrStr::DoingMyOwnMemOrStr) return;
   return __sanitizer_weak_hook_strcmp(called_pc, s1, s2, result);
 }
 
 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
 void __sanitizer_weak_hook_strstr(void *called_pc, const char *s1,
                                   const char *s2, char *result) {
+  if (fuzzer::ScopedDoingMyOwnMemOrStr::DoingMyOwnMemOrStr) return;
   TS->AddInterestingWord(reinterpret_cast<const uint8_t *>(s2), strlen(s2));
 }
 
 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
 void __sanitizer_weak_hook_strcasestr(void *called_pc, const char *s1,
                                       const char *s2, char *result) {
+  if (fuzzer::ScopedDoingMyOwnMemOrStr::DoingMyOwnMemOrStr) return;
   TS->AddInterestingWord(reinterpret_cast<const uint8_t *>(s2), strlen(s2));
 }
 
 ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
 void __sanitizer_weak_hook_memmem(void *called_pc, const void *s1, size_t len1,
                                   const void *s2, size_t len2, void *result) {
-  if (fuzzer::DoingMyOwnMemmem) return;
+  if (fuzzer::ScopedDoingMyOwnMemOrStr::DoingMyOwnMemOrStr) return;
   TS->AddInterestingWord(reinterpret_cast<const uint8_t *>(s2), len2);
 }