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 {
InitializeDeadlySignals()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
OnStackUnwind(const SignalContext & sig,const void *,BufferedStackTrace * stack)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
UBsanOnDeadlySignal(int signo,void * siginfo,void * context)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
InitializeDeadlySignals()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
69