From e18680bb11371772a7d351384aa17d670a3dbe72 Mon Sep 17 00:00:00 2001
From: Sir Richard <sir_richard@svn.reactos.org>
Date: Sat, 23 Jan 2010 19:28:26 +0000
Subject: [PATCH] [NTOS]: KiDispatchInterrupt crushes EBX, so maybe it should
 preserve it first? This only worked because KiDispatchInterrupt was only
 called by ASM code that already was magically aware of this fact, and
 preserved (or didn't use) EBX before making the call. Yuck!

svn path=/trunk/; revision=45212
---
 reactos/ntoskrnl/ke/i386/trap.s | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/reactos/ntoskrnl/ke/i386/trap.s b/reactos/ntoskrnl/ke/i386/trap.s
index ae72a1ba8be..cc2a202cec1 100644
--- a/reactos/ntoskrnl/ke/i386/trap.s
+++ b/reactos/ntoskrnl/ke/i386/trap.s
@@ -320,6 +320,9 @@ _KeUpdateSystemTime@0:
 .func KiDispatchInterrupt@0
 _KiDispatchInterrupt@0:
 
+    /* Preserve EBX */
+    push ebx
+
     /* Get the PCR  and disable interrupts */
     mov ebx, PCR[KPCR_SELF]
     cli
@@ -418,12 +421,14 @@ GetNext:
 
 Return:
     /* All done */
+    pop ebx
     ret
 
 QuantumEnd:
     /* Disable quantum end and process it */
     mov byte ptr [ebx+KPCR_PRCB_QUANTUM_END], 0
     call _KiQuantumEnd@0
+    pop ebx
     ret
 .endfunc