NtContinue fixed to return failure on invalid params ( not checking for access violations yet ), but not clobber EAX on success. This patch was made possiblel by the collaborative efforts of myself, kjk_hyperion, Art Yerkes, and Skywing.

reactos/ntoskrnl/ps/i386

diff -N continue.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ continue.c	2 Jul 2004 00:47:57 -0000	1.1
@@ -0,0 +1,99 @@

+/* $Id: continue.c,v 1.1 2004/07/02 00:47:57 royce Exp $
+ *
+ * COPYRIGHT:              See COPYING in the top level directory
+ * PROJECT:                ReactOS kernel
+ * FILE:                   ntoskrnl/ps/i386/continue.c
+ * PURPOSE:                i386 implementation of NtContinue()
+ * PROGRAMMER:             Royce Mitchell III, kjk_hyperion
+ * REVISION HISTORY:
+ *               29/06/04: Created
+ */
+
+/* INCLUDES ****************************************************************/
+
+#include <ddk/ntddk.h>
+#include <internal/ke.h>
+#include <internal/ob.h>
+#include <internal/ps.h>
+#include <internal/ob.h>
+#include <internal/pool.h>
+#include <ntos/minmax.h>
+#include <internal/ldr.h>
+#include <rosrtl/string.h>
+
+#define NDEBUG
+#include <internal/debug.h>
+
+#if 1
+VOID
+FASTCALL
+KeRosTrapReturn ( PKTRAP_FRAME TrapFrame, PKTRAP_FRAME PrevTrapFrame );
+
+VOID STDCALL
+KeRosDumpStackFrames ( PULONG Frame, ULONG FrameCount );
+
+/*
+ * @implemented
+ */
+NTSTATUS STDCALL
+NtContinue (
+	IN PCONTEXT Context,
+	IN BOOLEAN TestAlert)
+{
+	PKTRAP_FRAME TrapFrame = KeGetCurrentThread()->TrapFrame;
+	PKTRAP_FRAME PrevTrapFrame = (PKTRAP_FRAME)TrapFrame->Edx;
+
+	DPRINT1("NtContinue: Context: Eip=0x%x, Esp=0x%x\n", Context->Eip, Context->Esp );
+	PULONG Frame = 0;
+	__asm__("mov %%ebp, %%ebx" : "=b" (Frame) : );
+	DbgPrint ( "NtContinue(): Ebp=%x, prev/TF=%x/%x\n", Frame, Frame[0], TrapFrame );
+	KeRosDumpStackFrames(NULL,5);
+
+	if ( Context == NULL )
+	{
+		DPRINT1("NtContinue called with NULL Context\n");
+		return STATUS_INVALID_PARAMETER;
+	}
+
+	if ( TrapFrame == NULL )
+	{
+		CPRINT("NtContinue called but TrapFrame was NULL\n");
+		KEBUGCHECK(0);
+	}
+
+	/*
+	* Copy the supplied context over the register information that was saved
+	* on entry to kernel mode, it will then be restored on exit
+	* FIXME: Validate the context
+	*/
+	KeContextToTrapFrame ( Context, TrapFrame );
+
+	KeRosTrapReturn ( TrapFrame, PrevTrapFrame );
+
+	return STATUS_SUCCESS; /* this doesn't actually happen b/c KeRosTrapReturn() won't return */
+}
+#else
+NTSTATUS STDCALL
+NtContinue (
+	IN PCONTEXT Context,
+	IN BOOLEAN TestAlert)
+{
+	PKTRAP_FRAME TrapFrame = KeGetCurrentThread()->TrapFrame;
+	PULONG Frame = 0;
+	__asm__("mov %%ebp, %%ebx" : "=b" (Frame) : );
+	DbgPrint ( "NtContinue(): Ebp=%x, prev/TF=%x/%x\n", Frame, Frame[0], TrapFrame );
+
+	/*
+	 * Copy the supplied context over the register information that was saved
+	 * on entry to kernel mode, it will then be restored on exit
+	 * FIXME: Validate the context
+	 */
+	if ( TrapFrame == NULL )
+	{
+		CPRINT("NtContinue called but TrapFrame was NULL\n");
+		KEBUGCHECK(0);
+	}
+	KeContextToTrapFrame ( Context, TrapFrame );
+	return(STATUS_SUCCESS);
+}
+#endif