From 9f67c346522f7bddb7b3949001c80b324dfd0d5e Mon Sep 17 00:00:00 2001
From: Sir Richard <sir_richard@svn.reactos.org>
Date: Wed, 10 Feb 2010 03:59:17 +0000
Subject: [PATCH] [NTOS]: Allow registry configuration of large kernel stack
 size, with proper checks.

svn path=/trunk/; revision=45548
---
 reactos/ntoskrnl/mm/ARM3/i386/init.c | 22 ++++++++++++++++++++++
 reactos/ntoskrnl/mm/ARM3/mminit.c    |  2 +-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/reactos/ntoskrnl/mm/ARM3/i386/init.c b/reactos/ntoskrnl/mm/ARM3/i386/init.c
index 7c9ca592cf1..41b15734fb2 100644
--- a/reactos/ntoskrnl/mm/ARM3/i386/init.c
+++ b/reactos/ntoskrnl/mm/ARM3/i386/init.c
@@ -74,7 +74,29 @@ MiInitMachineDependent(IN PLOADER_PARAMETER_BLOCK LoaderBlock)
     PVOID NonPagedPoolExpansionVa;
     ULONG OldCount, L2Associativity;
     PFN_NUMBER FreePage, FreePageCount, PagesLeft, BasePage, PageCount;
+
+    /* Check for kernel stack size that's too big */
+    if (MmLargeStackSize > (KERNEL_LARGE_STACK_SIZE / 1024))
+    {
+        /* Sanitize to default value */
+        MmLargeStackSize = KERNEL_LARGE_STACK_SIZE;
+    }
+    else
+    {
+        /* Take the registry setting, and convert it into bytes */
+        MmLargeStackSize *= 1024;
         
+        /* Now align it to a page boundary */
+        MmLargeStackSize = PAGE_ROUND_UP(MmLargeStackSize);
+        
+        /* Sanity checks */
+        ASSERT(MmLargeStackSize <= KERNEL_LARGE_STACK_SIZE);
+        ASSERT((MmLargeStackSize & (PAGE_SIZE - 1)) == 0);
+        
+        /* Make sure it's not too low */
+        if (MmLargeStackSize < KERNEL_STACK_SIZE) MmLargeStackSize = KERNEL_STACK_SIZE;
+    }
+    
     //
     // The large kernel stack is cutomizable, but use default value for now
     //
diff --git a/reactos/ntoskrnl/mm/ARM3/mminit.c b/reactos/ntoskrnl/mm/ARM3/mminit.c
index 9829bb23218..21f666c81c3 100644
--- a/reactos/ntoskrnl/mm/ARM3/mminit.c
+++ b/reactos/ntoskrnl/mm/ARM3/mminit.c
@@ -232,7 +232,7 @@ ULONG MmSecondaryColorMask;
 //
 // Actual (registry-configurable) size of a GUI thread's stack
 //
-ULONG MmLargeStackSize;
+ULONG MmLargeStackSize = KERNEL_LARGE_STACK_SIZE;
 
 /* PRIVATE FUNCTIONS **********************************************************/