From 924a23029120072799b305c8f9607976450ff304 Mon Sep 17 00:00:00 2001
From: Magnus Olsen <magnus@greatlord.com>
Date: Thu, 12 Jul 2007 19:48:27 +0000
Subject: [PATCH] patch from w3seek ------------------ Don't mess with the
 stack in inline assembly because it cannot be assumed that the compiler
 magically knows where the local variables are located after changing the
 stack pointer manually.

See issue #2364 for more details.

svn path=/trunk/; revision=27618
---
 reactos/ntoskrnl/ke/i386/init.S   | 39 +++++++++++++++++++++
 reactos/ntoskrnl/ke/i386/kiinit.c | 56 +++++++++++++++++++------------
 reactos/ntoskrnl/ntoskrnl.rbuild  |  1 +
 3 files changed, 75 insertions(+), 21 deletions(-)
 create mode 100644 reactos/ntoskrnl/ke/i386/init.S

diff --git a/reactos/ntoskrnl/ke/i386/init.S b/reactos/ntoskrnl/ke/i386/init.S
new file mode 100644
index 00000000000..2d84d07f050
--- /dev/null
+++ b/reactos/ntoskrnl/ke/i386/init.S
@@ -0,0 +1,39 @@
+/*
+ * FILE:            ntoskrnl/ke/i386/init.S
+ * COPYRIGHT:       See COPYING in the top level directory
+ * PURPOSE:         Kernel Initialization
+ * PROGRAMMER:      Thomas Weidenmueller <w3seek@reactos.org>
+ */
+
+/* INCLUDES ******************************************************************/
+
+#include <asm.h>
+#include <internal/i386/asmmacro.S>
+.intel_syntax noprefix
+
+/* FUNCTIONS ******************************************************************/
+
+.text
+.globl _KiSetupStackAndInitializeKernel@24
+.func KiSetupStackAndInitializeKernel@24
+_KiSetupStackAndInitializeKernel@24:
+
+    mov esi, esp
+
+    /* Setup the new stack */
+    mov esp, [esp + 12]
+    sub esp, NPX_FRAME_LENGTH + KTRAP_FRAME_ALIGN + KTRAP_FRAME_LENGTH
+    push CR0_EM + CR0_TS + CR0_MP
+
+    /* Copy all parameters to the new stack */
+    push [esi + 24]
+    push [esi + 20]
+    push [esi + 16]
+    push [esi + 12]
+    push [esi + 8]
+    push [esi + 4]
+    xor ebp, ebp
+    call _KiInitializeKernel@24
+
+    jmp _KiSystemStartupFinal@0
+.endfunc
diff --git a/reactos/ntoskrnl/ke/i386/kiinit.c b/reactos/ntoskrnl/ke/i386/kiinit.c
index bff40a36a88..ef1b1b409e7 100644
--- a/reactos/ntoskrnl/ke/i386/kiinit.c
+++ b/reactos/ntoskrnl/ke/i386/kiinit.c
@@ -12,6 +12,16 @@
 #define NDEBUG
 #include <debug.h>
 
+
+VOID
+NTAPI
+KiSetupStackAndInitializeKernel(IN PKPROCESS InitProcess,
+                                IN PKTHREAD InitThread,
+                                IN PVOID IdleStack,
+                                IN PKPRCB Prcb,
+                                IN CCHAR Number,
+                                IN PLOADER_PARAMETER_BLOCK LoaderBlock);
+
 /* GLOBALS *******************************************************************/
 
 /* Spinlocks used only on X86 */
@@ -752,28 +762,32 @@ AppCpuInit:
     KfRaiseIrql(HIGH_LEVEL);
 
     /* Align stack and make space for the trap frame and NPX frame */
-    InitialStack &= -KTRAP_FRAME_ALIGN;
-#ifdef __GNUC__
-    __asm__ __volatile__("xorl %ebp, %ebp");
-    __asm__ __volatile__("movl %0,%%esp" : :"r" (InitialStack));
-    __asm__ __volatile__("subl %0,%%esp" : :"r" (NPX_FRAME_LENGTH +
-                                                 KTRAP_FRAME_LENGTH +
-                                                 KTRAP_FRAME_ALIGN));
-    __asm__ __volatile__("push %0" : :"r" (CR0_EM + CR0_TS + CR0_MP));
-#else
-    __asm xor ebp, ebp;
-    __asm mov esp, InitialStack;
-    __asm sub esp, NPX_FRAME_LENGTH + KTRAP_FRAME_ALIGN + KTRAP_FRAME_LENGTH;
-    __asm push CR0_EM + CR0_TS + CR0_MP;
-#endif
+    InitialStack &= ~(KTRAP_FRAME_ALIGN - 1);
 
-    /* Call main kernel initialization */
-    KiInitializeKernel(&KiInitialProcess.Pcb,
-                       InitialThread,
-                       (PVOID)InitialStack,
-                       (PKPRCB)__readfsdword(KPCR_PRCB),
-                       (CCHAR)Cpu,
-                       KeLoaderBlock);
+    /* NOTE: We cannot setup the stack using inline assembly and then later assume
+             that the compiler is smart enough to figure out how the stack layout
+             changed! This is to avoid generating wrong code. We cannot directly
+             call KiInitializeKernel from here! */
+
+    KiSetupStackAndInitializeKernel(&KiInitialProcess.Pcb,
+                                    InitialThread,
+                                    (PVOID)InitialStack,
+                                    (PKPRCB)__readfsdword(KPCR_PRCB),
+                                    (CCHAR)Cpu,
+                                    KeLoaderBlock);
+
+    /* NOTE: KiSetupStackAndInitializeKernel never returns! Do NOT add any code here! */
+    ASSERT(FALSE);
+}
+
+VOID
+NTAPI
+KiSystemStartupFinal(VOID)
+{
+    /* NOTE: This routine is called after setting up the stack in KiSystemStartup!
+             This code cannot be moved to KiSystemStartup because it cannot be assumed
+             that the compiler can generate working code after modifying ESP/EBP
+             using inline assembly! */
 
     /* Set the priority of this thread to 0 */
     KeGetCurrentThread()->Priority = 0;
diff --git a/reactos/ntoskrnl/ntoskrnl.rbuild b/reactos/ntoskrnl/ntoskrnl.rbuild
index d31e7bf3932..90acbe823a8 100644
--- a/reactos/ntoskrnl/ntoskrnl.rbuild
+++ b/reactos/ntoskrnl/ntoskrnl.rbuild
@@ -36,6 +36,7 @@
                 <file>cpu.c</file>
                 <file>ctxswitch.S</file>
                 <file>exp.c</file>
+                <file>init.S</file>
                 <file>irqobj.c</file>
                 <file>kiinit.c</file>
                 <file>ldt.c</file>