cleanup/reformat syscall code, save return value as soon as possible so that eax is freed up, which also simplifies the implementation of KiAfterSystemCallHook(), also removes a couple redundant instructions.

svn path=/trunk/; revision=9955

reactos/ntoskrnl/ke/i386/syscall.S

@@ -16,7 +16,7 @@
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
-/* $Id: syscall.S,v 1.14 2004/04/07 15:35:14 ekohl Exp $
+/* $Id: syscall.S,v 1.15 2004/07/01 01:52:37 royce Exp $
  *
  * FILE:            ntoskrnl/hal/x86/syscall.s
  * PURPOSE:         2E trap handler
@@ -28,6 +28,7 @@
 #include <ddk/status.h>
 #include <internal/i386/segment.h>
 #include <internal/ps.h>
+#include <internal/i386/ke.h>
 #include <roscfg.h>
 
 #define KernelMode  (0)
@@ -116,18 +117,18 @@ L3:
 	 * register.
 	 */
 	movl  KTHREAD_TRAP_FRAME(%esi), %ebx
-	   movl %ebx, 0x3C(%esp)
+	movl  %ebx, KTRAP_FRAME_EDX(%esp)
+
+	/*  Allocate new Kernel stack frame  */
+	movl  %esp,%ebp
 
 	/* Save a pointer to the trap frame in the TCB */
-	   movl	%esp, KTHREAD_TRAP_FRAME(%esi)
+	movl  %ebp, KTHREAD_TRAP_FRAME(%esi)
 
 	/*  Set ES to kernel segment  */
 	movw  $KERNEL_DS,%bx
 	movw  %bx,%es
 
-           /*  Allocate new Kernel stack frame  */
-           movl %esp,%ebp
-
 	/*  Users's current stack frame pointer is source  */
 	movl  %edx,%esi
 
@@ -139,6 +140,7 @@ L3:
 	cmpl  %es:_KeServiceDescriptorTable + 8, %eax
 	jbe   new_serviceInRange
 	movl  $STATUS_INVALID_SYSTEM_SERVICE, %eax
+	movl  %eax, KTRAP_FRAME_EAX(%ebp) /* save our return value in PKTRAP_FRAME->Eax */
 	jmp   KeReturnFromSystemCall
 
 new_serviceInRange:
@@ -174,21 +176,13 @@ new_serviceInRange:
 	movl  %es:_KeServiceDescriptorTable, %ecx
 	movl  %es:(%ecx, %eax, 4), %eax
 	call  *%eax
+	movl  %eax, KTRAP_FRAME_EAX(%ebp) /* save our return value in PKTRAP_FRAME->Eax */
 
 #if CHECKED
 	/*  Bump Service Counter  */
 #endif
 
-           /*  Deallocate the kernel stack frame  */
-           movl %ebp,%esp
-
-	   /* Call the post system call hook and deliver any pending APCs */
-	   pushl %ebp
-	   pushl %eax
-	   call _KiAfterSystemCallHook
-	   addl $8,%esp
-
-           jmp  KeReturnFromSystemCall
+	jmp   KeDeallocateStackAndReturnFromSystemCallWithHook
 
 new_useShadowTable:
 
@@ -198,6 +192,7 @@ new_useShadowTable:
 	cmpl  %es:_KeServiceDescriptorTableShadow + 24, %eax
 	jbe   new_shadowServiceInRange
 	movl  $STATUS_INVALID_SYSTEM_SERVICE, %eax
+	movl  %eax, KTRAP_FRAME_EAX(%ebp) /* save our return value in PKTRAP_FRAME->Eax */
 	jmp   KeReturnFromSystemCall
 
 new_shadowServiceInRange:
@@ -238,20 +233,21 @@ new_shadowServiceInRange:
 	movl  %es:_KeServiceDescriptorTableShadow + 16, %ecx
 	movl  %es:(%ecx, %eax, 4), %eax
 	call  *%eax
+	movl  %eax, KTRAP_FRAME_EAX(%ebp) /* save our return value in PKTRAP_FRAME->Eax */
 
 #if CHECKED
 	/* Bump Service Counter  */
 #endif
 
+KeDeallocateStackAndReturnFromSystemCallWithHook:
 	/* Deallocate the kernel stack frame  */
 	movl %ebp,%esp
 
 KeReturnFromSystemCallWithHook:
 	/* Call the post system call hook and deliver any pending APCs */
 	pushl %esp
-	   pushl %eax
 	call  _KiAfterSystemCallHook
-	   addl $8,%esp
+	addl  $4,%esp
 
 KeReturnFromSystemCall:
 
@@ -260,9 +256,10 @@ KeReturnFromSystemCall:
 	movl  %fs:0x124, %esi
 
 	/* Restore the old trap frame pointer */
-           movl 0x3c(%esp), %ebx
+	movl  KTRAP_FRAME_EDX(%esp), %ebx
 	movl  %ebx, KTHREAD_TRAP_FRAME(%esi)
 
+KiRosTrapReturn:
 	/* Skip debug information and unsaved registers */
 	addl  $0x30, %esp
 	popl  %gs
@@ -270,7 +267,7 @@ KeReturnFromSystemCall:
 	popl  %ds
 	popl  %edx
 	popl  %ecx
-	   addl $0x4, %esp   /* Don't restore eax */
+	popl  %eax
 
 	/* Restore the old previous mode */
 	popl  %ebx
@@ -288,3 +285,23 @@ KeReturnFromSystemCall:
 	addl  $0x4, %esp  /* Ignore error code */
 
 	iret
+
+/* R3: NOTE: This is part of my in-progress attempt at correcting NtContinue
+ *           It is not being called, yet...
+ */
+.globl @KeRosTrapReturn@8
+@KeRosTrapReturn@8:
+	/* Call the post system call hook and deliver any pending APCs */
+	pushl %esp
+	call  _KiAfterSystemCallHook
+	addl  $4,%esp
+
+	/* Restore the user context */
+	/* Get a pointer to the current thread */
+	movl  %fs:0x124, %esi
+	/* Restore the old trap frame pointer */
+	movl  %edx, KTHREAD_TRAP_FRAME(%esi)
+
+	/* point %esp to the trap frame to restore */
+	movl  %ecx, %esp
+	jmp   KiRosTrapReturn;

reactos/ntoskrnl/ke/i386/usercall.c

@@ -1,4 +1,4 @@
-/* $Id: usercall.c,v 1.26 2004/06/23 22:32:24 ion Exp $
+/* $Id: usercall.c,v 1.27 2004/07/01 01:52:37 royce Exp $
  *
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS kernel
@@ -26,7 +26,8 @@
 
 /* FUNCTIONS *****************************************************************/
 
-VOID KiSystemCallHook(ULONG Nr, ...)
+VOID
+KiSystemCallHook(ULONG Nr, ...)
 {
 #if 0
    va_list ap;
@@ -46,7 +47,8 @@ VOID KiSystemCallHook(ULONG Nr, ...)
 #endif
 }
 
-ULONG KiAfterSystemCallHook(ULONG NtStatus, PKTRAP_FRAME TrapFrame)
+VOID
+KiAfterSystemCallHook(PKTRAP_FRAME TrapFrame)
 {
   if (KeGetCurrentThread()->Alerted[1] != 0 && TrapFrame->Cs != KERNEL_CS)
     {
@@ -56,11 +58,11 @@ ULONG KiAfterSystemCallHook(ULONG NtStatus, PKTRAP_FRAME TrapFrame)
     {
       KiDeliverUserApc(TrapFrame);
     }
-  return(NtStatus);
 }
 
 
-VOID KiServiceCheck (ULONG Nr)
+VOID
+KiServiceCheck (ULONG Nr)
 {
   PETHREAD Thread;