diff --git a/llvm/lib/Support/CrashRecoveryContext.cpp b/llvm/lib/Support/CrashRecoveryContext.cpp
--- a/llvm/lib/Support/CrashRecoveryContext.cpp
+++ b/llvm/lib/Support/CrashRecoveryContext.cpp
@@ -392,7 +392,7 @@
   // Setup the signal handler.
   struct sigaction Handler;
   Handler.sa_handler = CrashRecoverySignalHandler;
-  Handler.sa_flags = 0;
+  Handler.sa_flags = SA_ONSTACK;
   sigemptyset(&Handler.sa_mask);
 
   for (unsigned i = 0; i != NumSignals; ++i) {