ubsan_signals_standalone.cpp revision 360784 
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
31namespace __ubsan {
32void InitializeDeadlySignals() {}
33}
34
35#else
36
37#define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name)
38#include "sanitizer_common/sanitizer_signal_interceptors.inc"
39
40// TODO(yln): Temporary workaround. Will be removed.
41void ubsan_GetStackTrace(BufferedStackTrace *stack, uptr max_depth,
42                         uptr pc, uptr bp, void *context, bool fast);
43
44namespace __ubsan {
45
46static void OnStackUnwind(const SignalContext &sig, const void *,
47                          BufferedStackTrace *stack) {
48  ubsan_GetStackTrace(stack, kStackTraceMax,
49                      StackTrace::GetNextInstructionPc(sig.pc), sig.bp,
50                      sig.context, common_flags()->fast_unwind_on_fatal);
51}
52
53static void UBsanOnDeadlySignal(int signo, void *siginfo, void *context) {
54  HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
55}
56
57static bool is_initialized = false;
58
59void InitializeDeadlySignals() {
60  if (is_initialized)
61    return;
62  is_initialized = true;
63  InitializeSignalInterceptors();
64  InstallDeadlySignalHandlers(&UBsanOnDeadlySignal);
65}
66
67} // namespace __ubsan
68
69#endif
70
71#endif // CAN_SANITIZE_UB
72