[MSan] Fixup for r206983: MsanThread may be unavailable in signal handler: signals may be raised while thread is being destroyed

llvm-svn: 208250

2 files changed, 10 insertions, 3 deletions

diff --git a/compiler-rt/lib/msan/msan.cc b/compiler-rt/lib/msan/msan.cc
index cb3498ef847..60004a133de 100644
--- a/compiler-rt/lib/msan/msan.cc
+++ b/compiler-rt/lib/msan/msan.cc
@@ -237,7 +237,8 @@ const char *GetOriginDescrIfStack(u32 id, uptr *pc) {
 }
 
 u32 ChainOrigin(u32 id, StackTrace *stack) {
-  if (GetCurrentThread()->InSignalHandler())
+  MsanThread *t = GetCurrentThread();
+  if (t && t->InSignalHandler())
     return id;
   uptr idx = Min(stack->size, kStackTraceMax - 1);
   stack->trace[idx] = TRACE_MAKE_CHAINED(id);
diff --git a/compiler-rt/lib/msan/msan_interceptors.cc b/compiler-rt/lib/msan/msan_interceptors.cc
index e71c4045854..65acf0d3e1c 100644
--- a/compiler-rt/lib/msan/msan_interceptors.cc
+++ b/compiler-rt/lib/msan/msan_interceptors.cc
@@ -982,8 +982,14 @@ INTERCEPTOR(int, getrusage, int who, void *usage) {
 
 class SignalHandlerScope {
  public:
-  SignalHandlerScope() { GetCurrentThread()->EnterSignalHandler(); }
-  ~SignalHandlerScope() { GetCurrentThread()->LeaveSignalHandler(); }
+  SignalHandlerScope() {
+    if (MsanThread *t = GetCurrentThread())
+      t->EnterSignalHandler();
+  }
+  ~SignalHandlerScope() {
+    if (MsanThread *t = GetCurrentThread())
+      t->LeaveSignalHandler();
+  }
 };
 
 // sigactions_mu guarantees atomicity of sigaction() and signal() calls.