82 lines · 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-exception6//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_UB16#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 for23// the interceptors to work correctly. This complicates deployment, as it24// 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 the26// debuggerd handler, but before the ART handler.27// * Interceptors don't work at all when ubsan runtime is loaded late, ex. when28// it is part of an APK that does not use wrap.sh method.29#if SANITIZER_FUCHSIA || SANITIZER_ANDROID30 31namespace __ubsan {32void InitializeDeadlySignals() {}33}34 35#else36 37namespace __ubsan {38void InitializeDeadlySignals();39} // namespace __ubsan40 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.46void ubsan_GetStackTrace(BufferedStackTrace *stack, uptr max_depth,47 uptr pc, uptr bp, void *context, bool fast);48 49namespace __ubsan {50 51static 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 58static void UBsanOnDeadlySignal(int signo, void *siginfo, void *context) {59 HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);60}61 62static bool is_initialized = false;63 64void InitializeDeadlySignals() {65 if (is_initialized)66 return;67 is_initialized = true;68 InitializeSignalInterceptors();69#if SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION70 // REAL(sigaction_symname) is nullptr in a static link. Bail out.71 if (!REAL(sigaction_symname))72 return;73#endif74 InstallDeadlySignalHandlers(&UBsanOnDeadlySignal);75}76 77} // namespace __ubsan78 79#endif80 81#endif // CAN_SANITIZE_UB82