libsanitizer/ubsan/ubsan_signals_standalone.cc

   1 //=-- ubsan_signals_standalone.cc
   2 //------------------------------------------------===//
   3 //
   4 //                     The LLVM Compiler Infrastructure
   5 //
   6 // This file is distributed under the University of Illinois Open Source
   7 // License. See LICENSE.TXT for details.
   8 //
   9 //===----------------------------------------------------------------------===//
  10 //
  11 // Installs signal handlers and related interceptors for UBSan standalone.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "ubsan_platform.h"
  16 #include "sanitizer_common/sanitizer_platform.h"
  17 #if CAN_SANITIZE_UB
  18 #include "interception/interception.h"
  19 #include "sanitizer_common/sanitizer_stacktrace.h"
  20 #include "ubsan_diag.h"
  21 #include "ubsan_init.h"
  22
  23 // Interception of signals breaks too many things on Android.
  24 // * It requires that ubsan is the first dependency of the main executable for
  25 // the interceptors to work correctly. This complicates deployment, as it
  26 // prevents us from enabling ubsan on random platform modules independently.
  27 // * For this to work with ART VM, ubsan signal handler has to be set after the
  28 // debuggerd handler, but before the ART handler.
  29 // * Interceptors don't work at all when ubsan runtime is loaded late, ex. when
  30 // it is part of an APK that does not use wrap.sh method.
  31 #if SANITIZER_FUCHSIA || SANITIZER_ANDROID
  32
  33 namespace __ubsan {
  34 void InitializeDeadlySignals() {}
  35 }
  36
  37 #else
  38
  39 #define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name)
  40 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
  41
  42 namespace __ubsan {
  43
  44 static void OnStackUnwind(const SignalContext &sig, const void *,
  45                           BufferedStackTrace *stack) {
  46   GetStackTrace(stack, kStackTraceMax, sig.pc, sig.bp, sig.context,
  47                 common_flags()->fast_unwind_on_fatal);
  48 }
  49
  50 static void UBsanOnDeadlySignal(int signo, void *siginfo, void *context) {
  51   HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
  52 }
  53
  54 static bool is_initialized = false;
  55
  56 void InitializeDeadlySignals() {
  57   if (is_initialized)
  58     return;
  59   is_initialized = true;
  60   InitializeSignalInterceptors();
  61   InstallDeadlySignalHandlers(&UBsanOnDeadlySignal);
  62 }
  63
  64 } // namespace __ubsan
  65
  66 #endif
  67
  68 #endif // CAN_SANITIZE_UB