[libFuzzer] Improve Signal Handler interface.

Add new flags to FuzzingOptions to represent the different conditions
on the signal handling. These options are passed when calling
SetSignalHandler().
This changes simplify the implementation of Windows's exception
handling. Now we can define a unique handler for all the exceptions.

Differential Revision: https://reviews.llvm.org/D27238

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289557 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Fuzzer/FuzzerDriver.cpp

@@ -457,16 +457,14 @@ int FuzzerDriver(int *argc, char ***argv, UserCallback Callback) {
 
   StartRssThread(F, Flags.rss_limit_mb);
 
-  // Timer
-  if (Flags.timeout > 0)
-    SetTimer(Flags.timeout / 2 + 1);
-  if (Flags.handle_segv) SetSigSegvHandler();
-  if (Flags.handle_bus) SetSigBusHandler();
-  if (Flags.handle_abrt) SetSigAbrtHandler();
-  if (Flags.handle_ill) SetSigIllHandler();
-  if (Flags.handle_fpe) SetSigFpeHandler();
-  if (Flags.handle_int) SetSigIntHandler();
-  if (Flags.handle_term) SetSigTermHandler();
+  Options.HandleAbrt = Flags.handle_abrt;
+  Options.HandleBus = Flags.handle_bus;
+  Options.HandleFpe = Flags.handle_fpe;
+  Options.HandleIll = Flags.handle_ill;
+  Options.HandleInt = Flags.handle_int;
+  Options.HandleSegv = Flags.handle_segv;
+  Options.HandleTerm = Flags.handle_term;
+  SetSignalHandler(Options);
 
   if (Flags.minimize_crash_internal_step)
     return MinimizeCrashInputInternalStep(F, Corpus);

lib/Fuzzer/FuzzerOptions.h

@@ -53,6 +53,13 @@ struct FuzzingOptions {
   bool PrintCoverage = false;
   bool DetectLeaks = true;
   int  TraceMalloc = 0;
+  bool HandleAbrt = false;
+  bool HandleBus = false;
+  bool HandleFpe = false;
+  bool HandleIll = false;
+  bool HandleInt = false;
+  bool HandleSegv = false;
+  bool HandleTerm = false;
 };
 
 }  // namespace fuzzer

lib/Fuzzer/FuzzerUtil.h

@@ -43,15 +43,7 @@ int NumberOfCpuCores();
 bool ExecuteCommandAndReadOutput(const std::string &Command, std::string *Out);
 
 // Platform specific functions.
-void SetTimer(int Seconds);
-
-void SetSigSegvHandler();
-void SetSigBusHandler();
-void SetSigAbrtHandler();
-void SetSigIllHandler();
-void SetSigFpeHandler();
-void SetSigIntHandler();
-void SetSigTermHandler();
+void SetSignalHandler(const FuzzingOptions& Options);
 
 void SleepSeconds(int Seconds);
 

lib/Fuzzer/FuzzerUtilPosix.cpp

@@ -64,13 +64,24 @@ void SetTimer(int Seconds) {
   SetSigaction(SIGALRM, AlarmHandler);
 }
 
-void SetSigSegvHandler() { SetSigaction(SIGSEGV, CrashHandler); }
-void SetSigBusHandler() { SetSigaction(SIGBUS, CrashHandler); }
-void SetSigAbrtHandler() { SetSigaction(SIGABRT, CrashHandler); }
-void SetSigIllHandler() { SetSigaction(SIGILL, CrashHandler); }
-void SetSigFpeHandler() { SetSigaction(SIGFPE, CrashHandler); }
-void SetSigIntHandler() { SetSigaction(SIGINT, InterruptHandler); }
-void SetSigTermHandler() { SetSigaction(SIGTERM, InterruptHandler); }
+void SetSignalHandler(const FuzzingOptions& Options) {
+  if (Options.UnitTimeoutSec > 0)
+    SetTimer(Options.UnitTimeoutSec / 2 + 1);
+  if (Options.HandleInt)
+    SetSigaction(SIGINT, InterruptHandler);
+  if (Options.HandleTerm)
+    SetSigaction(SIGTERM, InterruptHandler);
+  if (Options.HandleSegv)
+    SetSigaction(SIGSEGV, CrashHandler);
+  if (Options.HandleBus)
+    SetSigaction(SIGBUS, CrashHandler);
+  if (Options.HandleAbrt)
+    SetSigaction(SIGABRT, CrashHandler);
+  if (Options.HandleIll)
+    SetSigaction(SIGILL, CrashHandler);
+  if (Options.HandleFpe)
+    SetSigaction(SIGFPE, CrashHandler);
+}
 
 void SleepSeconds(int Seconds) {
   sleep(Seconds); // Use C API to avoid coverage from instrumented libc++.

lib/Fuzzer/FuzzerUtilWindows.cpp

@@ -13,7 +13,6 @@
 #if LIBFUZZER_WINDOWS
 #include "FuzzerIO.h"
 #include "FuzzerInternal.h"
-#include <Psapi.h>
 #include <cassert>
 #include <chrono>
 #include <cstring>
@@ -24,75 +23,58 @@
 #include <stdio.h>
 #include <sys/types.h>
 #include <windows.h>
+#include <Psapi.h>
 
 namespace fuzzer {
 
-LONG WINAPI SEGVHandler(PEXCEPTION_POINTERS ExceptionInfo) {
+static const FuzzingOptions* HandlerOpt = nullptr;
+
+LONG CALLBACK ExceptionHandler(PEXCEPTION_POINTERS ExceptionInfo) {
   switch (ExceptionInfo->ExceptionRecord->ExceptionCode) {
-  case EXCEPTION_ACCESS_VIOLATION:
-  case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
-  case EXCEPTION_STACK_OVERFLOW:
-    Fuzzer::StaticCrashSignalCallback();
-    break;
+    case EXCEPTION_ACCESS_VIOLATION:
+    case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
+    case EXCEPTION_STACK_OVERFLOW:
+      if (HandlerOpt->HandleSegv)
+        Fuzzer::StaticCrashSignalCallback();
+      break;
+    case EXCEPTION_DATATYPE_MISALIGNMENT:
+    case EXCEPTION_IN_PAGE_ERROR:
+      if (HandlerOpt->HandleBus)
+        Fuzzer::StaticCrashSignalCallback();
+      break;
+    case EXCEPTION_ILLEGAL_INSTRUCTION:
+    case EXCEPTION_PRIV_INSTRUCTION:
+      if (HandlerOpt->HandleIll)
+        Fuzzer::StaticCrashSignalCallback();
+      break;
+    case EXCEPTION_FLT_DENORMAL_OPERAND:
+    case EXCEPTION_FLT_DIVIDE_BY_ZERO:
+    case EXCEPTION_FLT_INEXACT_RESULT:
+    case EXCEPTION_FLT_INVALID_OPERATION:
+    case EXCEPTION_FLT_OVERFLOW:
+    case EXCEPTION_FLT_STACK_CHECK:
+    case EXCEPTION_FLT_UNDERFLOW:
+    case EXCEPTION_INT_DIVIDE_BY_ZERO:
+    case EXCEPTION_INT_OVERFLOW:
+      if (HandlerOpt->HandleFpe)
+        Fuzzer::StaticCrashSignalCallback();
+      break;
   }
   return EXCEPTION_CONTINUE_SEARCH;
 }
 
-LONG WINAPI BUSHandler(PEXCEPTION_POINTERS ExceptionInfo) {
-  switch (ExceptionInfo->ExceptionRecord->ExceptionCode) {
-  case EXCEPTION_DATATYPE_MISALIGNMENT:
-  case EXCEPTION_IN_PAGE_ERROR:
-    Fuzzer::StaticCrashSignalCallback();
-    break;
-  }
-  return EXCEPTION_CONTINUE_SEARCH;
-}
-
-LONG WINAPI ILLHandler(PEXCEPTION_POINTERS ExceptionInfo) {
-  switch (ExceptionInfo->ExceptionRecord->ExceptionCode) {
-  case EXCEPTION_ILLEGAL_INSTRUCTION:
-  case EXCEPTION_PRIV_INSTRUCTION:
-    Fuzzer::StaticCrashSignalCallback();
-    break;
-  }
-  return EXCEPTION_CONTINUE_SEARCH;
-}
-
-LONG WINAPI FPEHandler(PEXCEPTION_POINTERS ExceptionInfo) {
-  switch (ExceptionInfo->ExceptionRecord->ExceptionCode) {
-  case EXCEPTION_FLT_DENORMAL_OPERAND:
-  case EXCEPTION_FLT_DIVIDE_BY_ZERO:
-  case EXCEPTION_FLT_INEXACT_RESULT:
-  case EXCEPTION_FLT_INVALID_OPERATION:
-  case EXCEPTION_FLT_OVERFLOW:
-  case EXCEPTION_FLT_STACK_CHECK:
-  case EXCEPTION_FLT_UNDERFLOW:
-  case EXCEPTION_INT_DIVIDE_BY_ZERO:
-  case EXCEPTION_INT_OVERFLOW:
-    Fuzzer::StaticCrashSignalCallback();
-    break;
-  }
-  return EXCEPTION_CONTINUE_SEARCH;
-}
-
-BOOL WINAPI INTHandler(DWORD dwCtrlType) {
+BOOL WINAPI CtrlHandler(DWORD dwCtrlType) {
   switch (dwCtrlType) {
-  case CTRL_C_EVENT:
-    Fuzzer::StaticInterruptCallback();
-    return TRUE;
-  default:
-    return FALSE;
-  }
-}
-
-BOOL WINAPI TERMHandler(DWORD dwCtrlType) {
-  switch (dwCtrlType) {
-  case CTRL_BREAK_EVENT:
-    Fuzzer::StaticInterruptCallback();
-    return TRUE;
-  default:
-    return FALSE;
+    case CTRL_C_EVENT:
+      if (HandlerOpt->HandleInt)
+        Fuzzer::StaticInterruptCallback();
+      return TRUE;
+    case CTRL_BREAK_EVENT:
+      if (HandlerOpt->HandleTerm)
+        Fuzzer::StaticInterruptCallback();
+      return TRUE;
   }
+  return FALSE;
 }
 
 void CALLBACK AlarmHandler(PVOID, BOOLEAN) {
@@ -126,59 +108,34 @@ class TimerQ {
 
 static TimerQ Timer;
 
-void SetTimer(int Seconds) {
-  Timer.SetTimer(Seconds);
-  return;
-}
-
-void SetSigSegvHandler() {
-  if (!AddVectoredExceptionHandler(1, SEGVHandler)) {
-    Printf("libFuzzer: AddVectoredExceptionHandler failed.\n");
-    exit(1);
-  }
-}
-
-void SetSigBusHandler() {
-  if (!AddVectoredExceptionHandler(1, BUSHandler)) {
-    Printf("libFuzzer: AddVectoredExceptionHandler failed.\n");
-    exit(1);
-  }
-}
-
 static void CrashHandler(int) { Fuzzer::StaticCrashSignalCallback(); }
 
-void SetSigAbrtHandler() { signal(SIGABRT, CrashHandler); }
+void SetSignalHandler(const FuzzingOptions& Options) {
+  HandlerOpt = &Options;
 
-void SetSigIllHandler() {
-  if (!AddVectoredExceptionHandler(1, ILLHandler)) {
-    Printf("libFuzzer: AddVectoredExceptionHandler failed.\n");
-    exit(1);
-  }
-}
+  if (Options.UnitTimeoutSec > 0)
+    Timer.SetTimer(Options.UnitTimeoutSec / 2 + 1);
 
-void SetSigFpeHandler() {
-  if (!AddVectoredExceptionHandler(1, FPEHandler)) {
-    Printf("libFuzzer: AddVectoredExceptionHandler failed.\n");
-    exit(1);
-  }
-}
+  if (Options.HandleInt || Options.HandleTerm)
+    if (!SetConsoleCtrlHandler(CtrlHandler, TRUE)) {
+      DWORD LastError = GetLastError();
+      Printf("libFuzzer: SetConsoleCtrlHandler failed (Error code: %lu).\n",
+        LastError);
+      exit(1);
+    }
 
-void SetSigIntHandler() {
-  if (!SetConsoleCtrlHandler(INTHandler, TRUE)) {
-    DWORD LastError = GetLastError();
-    Printf("libFuzzer: SetConsoleCtrlHandler failed (Error code: %lu).\n",
-           LastError);
-    exit(1);
-  }
-}
+  if (Options.HandleSegv || Options.HandleBus || Options.HandleIll ||
+      Options.HandleFpe)
+    if (!AddVectoredExceptionHandler(1, ExceptionHandler)) {
+      Printf("libFuzzer: AddVectoredExceptionHandler failed.\n");
+      exit(1);
+    }
 
-void SetSigTermHandler() {
-  if (!SetConsoleCtrlHandler(TERMHandler, TRUE)) {
-    DWORD LastError = GetLastError();
-    Printf("libFuzzer: SetConsoleCtrlHandler failed (Error code: %lu).\n",
-           LastError);
-    exit(1);
-  }
+  if (Options.HandleAbrt)
+    if (SIG_ERR == signal(SIGABRT, CrashHandler)) {
+      Printf("libFuzzer: signal failed with %d\n", errno);
+      exit(1);
+    }
 }
 
 void SleepSeconds(int Seconds) { Sleep(Seconds * 1000); }