libsanitizer/ubsan/ubsan_signals_standalone.cpp

   1 //=-- ubsan_signals_standalone.cpp ----------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Installs signal handlers and related interceptors for UBSan standalone.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "ubsan_platform.h"
  14 #include "sanitizer_common/sanitizer_platform.h"
  15 #if CAN_SANITIZE_UB
  16 #include "interception/interception.h"
  17 #include "sanitizer_common/sanitizer_stacktrace.h"
  18 #include "ubsan_diag.h"
  19 #include "ubsan_init.h"
  20
  21 // Interception of signals breaks too many things on Android.
  22 // * It requires that ubsan is the first dependency of the main executable for
  23 // the interceptors to work correctly. This complicates deployment, as it
  24 // prevents us from enabling ubsan on random platform modules independently.
  25 // * For this to work with ART VM, ubsan signal handler has to be set after the
  26 // debuggerd handler, but before the ART handler.
  27 // * Interceptors don't work at all when ubsan runtime is loaded late, ex. when
  28 // it is part of an APK that does not use wrap.sh method.
  29 #if SANITIZER_FUCHSIA || SANITIZER_ANDROID
  30
  31 namespace __ubsan {
  32 void InitializeDeadlySignals() {}
  33 }
  34
  35 #else
  36
  37 namespace __ubsan {
  38 void InitializeDeadlySignals();
  39 } // namespace __ubsan
  40
  41 #define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name)
  42 #define SIGNAL_INTERCEPTOR_ENTER() __ubsan::InitializeDeadlySignals()
  43 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
  44
  45 // TODO(yln): Temporary workaround. Will be removed.
  46 void ubsan_GetStackTrace(BufferedStackTrace *stack, uptr max_depth,
  47                          uptr pc, uptr bp, void *context, bool fast);
  48
  49 namespace __ubsan {
  50
  51 static void OnStackUnwind(const SignalContext &sig, const void *,
  52                           BufferedStackTrace *stack) {
  53   ubsan_GetStackTrace(stack, kStackTraceMax,
  54                       StackTrace::GetNextInstructionPc(sig.pc), sig.bp,
  55                       sig.context, common_flags()->fast_unwind_on_fatal);
  56 }
  57
  58 static void UBsanOnDeadlySignal(int signo, void *siginfo, void *context) {
  59   HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
  60 }
  61
  62 static bool is_initialized = false;
  63
  64 void InitializeDeadlySignals() {
  65   if (is_initialized)
  66     return;
  67   is_initialized = true;
  68   InitializeSignalInterceptors();
  69   InstallDeadlySignalHandlers(&UBsanOnDeadlySignal);
  70 }
  71
  72 } // namespace __ubsan
  73
  74 #endif
  75
  76 #endif // CAN_SANITIZE_UB