From 4a3ce7bcb92e58113805e8104c92315ccad82c92 Mon Sep 17 00:00:00 2001
From: Rajat Dua <radua@microsoft.com>
Date: Thu, 26 Jul 2018 12:14:36 -0700
Subject: [PATCH] Don't allocate in pre-reserved section if we had failed to
 reserve it on jit server init time. OS#15209418

---
 lib/Backend/ServerThreadContext.cpp | 6 ++++++
 lib/Backend/ServerThreadContext.h   | 2 +-
 lib/JITServer/JITServer.cpp         | 1 +
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/lib/Backend/ServerThreadContext.cpp b/lib/Backend/ServerThreadContext.cpp
index 37093123181..be1827b63a8 100644
--- a/lib/Backend/ServerThreadContext.cpp
+++ b/lib/Backend/ServerThreadContext.cpp
@@ -169,6 +169,12 @@ ServerThreadContext::CanCreatePreReservedSegment() const
     return m_canCreatePreReservedSegment;
 }
 
+void
+ServerThreadContext::SetCanCreatePreReservedSegment(bool value)
+{
+    m_canCreatePreReservedSegment = value;
+}
+
 bool
 ServerThreadContext::IsNumericProperty(Js::PropertyId propertyId)
 {
diff --git a/lib/Backend/ServerThreadContext.h b/lib/Backend/ServerThreadContext.h
index 7aa1d258415..26e2a9de649 100644
--- a/lib/Backend/ServerThreadContext.h
+++ b/lib/Backend/ServerThreadContext.h
@@ -72,7 +72,7 @@ class ServerThreadContext : public ThreadContextInfo
     intptr_t GetRuntimeChakraBaseAddress() const;
     intptr_t GetRuntimeCRTBaseAddress() const;
     bool CanCreatePreReservedSegment() const;
-
+    void SetCanCreatePreReservedSegment(bool value);
     static intptr_t GetJITCRTBaseAddress();
 
 private:
diff --git a/lib/JITServer/JITServer.cpp b/lib/JITServer/JITServer.cpp
index 5712447bcef..b86fd3d5841 100644
--- a/lib/JITServer/JITServer.cpp
+++ b/lib/JITServer/JITServer.cpp
@@ -221,6 +221,7 @@ ServerInitializeThreadContext(
         if (!PHASE_OFF1(Js::PreReservedHeapAllocPhase))
         {
             *prereservedRegionAddr = (intptr_t)contextInfo->GetPreReservedSectionAllocator()->EnsurePreReservedRegion();
+            contextInfo->SetCanCreatePreReservedSegment(*prereservedRegionAddr != 0);
         }
 #if !defined(_M_ARM)
         *jitThunkAddr = (intptr_t)contextInfo->GetJITThunkEmitter()->EnsureInitialized();