From 47d309b262b302cb86fe72d689a616bbbde3a7d4 Mon Sep 17 00:00:00 2001
From: Pierre Schweitzer <pierre@reactos.org>
Date: Sat, 17 Nov 2018 15:03:43 +0100
Subject: [PATCH] [NTOSKRNL] Implement ExSizeOfRundownProtectionCacheAware()

---
 ntoskrnl/ex/rundown.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/ntoskrnl/ex/rundown.c b/ntoskrnl/ex/rundown.c
index 5b354857e34..ee1dbadb2b8 100644
--- a/ntoskrnl/ex/rundown.c
+++ b/ntoskrnl/ex/rundown.c
@@ -606,13 +606,28 @@ ExInitializeRundownProtectionCacheAware(IN PEX_RUNDOWN_REF_CACHE_AWARE RunRefCac
 }
 
 /*
- * @unimplemented NT5.2
+ * @implemented NT5.2
  */
 SIZE_T
 NTAPI
 ExSizeOfRundownProtectionCacheAware(VOID)
 {
-    UNIMPLEMENTED;
-    return 0;
+    SIZE_T Size;
+
+    PAGED_CODE();
+
+    /* Compute the needed size for runrefs */
+    if (KeNumberProcessors <= 1)
+    {
+        Size = sizeof(EX_RUNDOWN_REF);
+    }
+    else
+    {
+        /* We +1, to have enough room for alignment */
+        Size = (KeNumberProcessors + 1) * KeGetRecommendedSharedDataAlignment();
+    }
+
+    /* Return total size (master structure and runrefs) */
+    return Size + sizeof(EX_RUNDOWN_REF_CACHE_AWARE);
 }