[PATCH v6 1/2] ntoskrnl.exe: Implement KeAcquireGuardedMutex.

[Etaash Mathamsetty]

From: Etaash Mathamsetty

---
 dlls/ntoskrnl.exe/ntoskrnl.exe.spec |  2 ++
 dlls/ntoskrnl.exe/sync.c            | 23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
index 2447d01458d..8a67ebdf4c8 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
+++ b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
@@ -50,6 +50,8 @@
 @ stdcall -fastcall IofCompleteRequest(ptr long)
 @ stdcall -arch=!i386 KeAcquireInStackQueuedSpinLock(ptr ptr)
 @ stdcall -fastcall KeAcquireInStackQueuedSpinLockAtDpcLevel(ptr ptr)
+@ stdcall KeAcquireGuardedMutexUnsafe(ptr)
+@ stdcall KeAcquireGuardedMutex(ptr)
 @ stdcall KeEnterGuardedRegion()
 @ stdcall KeExpandKernelStackAndCallout(ptr ptr long)
 @ stdcall KeExpandKernelStackAndCalloutEx(ptr ptr long long ptr)
diff --git a/dlls/ntoskrnl.exe/sync.c b/dlls/ntoskrnl.exe/sync.c
index d9b5726b920..2c227974cd7 100644
--- a/dlls/ntoskrnl.exe/sync.c
+++ b/dlls/ntoskrnl.exe/sync.c
@@ -439,6 +439,29 @@ void WINAPI KeInitializeGuardedMutex(PKGUARDED_MUTEX mutex)
     KeInitializeEvent(&mutex->Event, SynchronizationEvent, FALSE);
 }

+/***********************************************************************
+ *           KeAcquireGuardedMutexUnsafe   (NTOSKRNL.EXE.@)
+ */
+void WINAPI KeAcquireGuardedMutexUnsafe(PKGUARDED_MUTEX mutex)
+{
+    LONG count; 
+
+    TRACE("mutex %p.\n", mutex);
+
+    count = InterlockedDecrement( &mutex->Count );
+    if (count < 0)
+        KeWaitForSingleObject( &mutex->Event, Executive, KernelMode, FALSE, NULL );
+}
+
+/***********************************************************************
+ *           KeAcquireGuardedMutex   (NTOSKRNL.EXE.@)
+ */
+void WINAPI KeAcquireGuardedMutex(PKGUARDED_MUTEX mutex)
+{
+    /* FIXME: Enter Guarded Region */
+    KeAcquireGuardedMutexUnsafe(mutex);
+}
+
 static void CALLBACK ke_timer_complete_proc(PTP_CALLBACK_INSTANCE instance, void *timer_, PTP_TIMER tp_timer)
 {
     KTIMER *timer = timer_;