From 2d5d058d2f10de78d759aba4512d195736a5606d Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Sat, 19 Dec 2020 11:05:24 -0800
Subject: [PATCH] dll: FspFsctlStartService:make thread safe

---
 src/dll/fsctl.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/dll/fsctl.c b/src/dll/fsctl.c
index f666b847..9fad2ae1 100644
--- a/src/dll/fsctl.c
+++ b/src/dll/fsctl.c
@@ -254,6 +254,7 @@ FSP_API NTSTATUS FspFsctlPreflight(PWSTR DevicePath)
 
 static NTSTATUS FspFsctlStartService(VOID)
 {
+    static SRWLOCK Lock = SRWLOCK_INIT;
     PWSTR DriverName = L"" FSP_FSCTL_DRIVER_NAME;
     SC_HANDLE ScmHandle = 0;
     SC_HANDLE SvcHandle = 0;
@@ -261,6 +262,8 @@ static NTSTATUS FspFsctlStartService(VOID)
     DWORD LastError;
     NTSTATUS Result;
 
+    AcquireSRWLockExclusive(&Lock);
+
     /* Determine if we are running inside container.
      *
      * See https://github.com/microsoft/perfview/blob/V1.9.65/src/TraceEvent/TraceEventSession.cs#L525
@@ -331,6 +334,8 @@ exit:
     if (0 != ScmHandle)
         CloseServiceHandle(ScmHandle);
 
+    ReleaseSRWLockExclusive(&Lock);
+
     return Result;
 }