Snap for 7447849 from 53c0cb0f22e0149090e719f6a5db7793d7f04346 to sc-v2-release

Change-Id: I9959e8306a91e2ac0b543ab139f2cdc051534871
diff --git a/PtracerThread.cpp b/PtracerThread.cpp
index d2fca49..78d6768 100644
--- a/PtracerThread.cpp
+++ b/PtracerThread.cpp
@@ -68,7 +68,7 @@
 };
 
 PtracerThread::PtracerThread(const std::function<int()>& func) : child_pid_(0) {
-  stack_ = std::make_unique<Stack>(PTHREAD_STACK_MIN);
+  stack_ = std::make_unique<Stack>(128*PAGE_SIZE);
   if (stack_->top() == nullptr) {
     MEM_LOG_ALWAYS_FATAL("failed to mmap child stack: %s", strerror(errno));
   }