[ros-diffs] [hbelusca] 62305: [NTVDM]: Limit the number of CPU recursion calls (not more than 32).

Author: hbelusca
Date: Sun Feb 23 15:54:20 2014
New Revision: 62305

URL: http://svn.reactos.org/svn/reactos?rev=62305&view=rev
Log:
[NTVDM]: Limit the number of CPU recursion calls (not more than 32).

Modified:
    branches/ntvdm/subsystems/ntvdm/callback.c
    branches/ntvdm/subsystems/ntvdm/clock.c
    branches/ntvdm/subsystems/ntvdm/emulator.c

Modified: branches/ntvdm/subsystems/ntvdm/callback.c
URL: http://svn.reactos.org/svn/reactos/branches/ntvdm/subsystems/ntvdm/callback....
==============================================================================
--- branches/ntvdm/subsystems/ntvdm/callback.c	[iso-8859-1] (original)
+++ branches/ntvdm/subsystems/ntvdm/callback.c	[iso-8859-1] Sun Feb 23 15:54:20 2014
@@ -102,7 +102,7 @@

DPRINT("Call16(0x%04X, 0x%04X)\n", Segment, Offset);

-    /* Start simulation */
+    /* Start CPU simulation */
     EmulatorSimulate();

/* Restore CS:IP */

Modified: branches/ntvdm/subsystems/ntvdm/clock.c
URL: http://svn.reactos.org/svn/reactos/branches/ntvdm/subsystems/ntvdm/clock.c?r...
==============================================================================
--- branches/ntvdm/subsystems/ntvdm/clock.c	[iso-8859-1] (original)
+++ branches/ntvdm/subsystems/ntvdm/clock.c	[iso-8859-1] Sun Feb 23 15:54:20 2014
@@ -59,6 +59,7 @@

VOID ClockUpdate(VOID)
 {
+    extern BOOLEAN CpuSimulate;
     UINT i;

#ifdef WORKING_TIMER
@@ -127,7 +128,7 @@
     VgaHorizontalRetrace();

/* Continue CPU emulation */
-    for (i = 0; (i < STEPS_PER_CYCLE) && VdmRunning; i++)
+    for (i = 0; VdmRunning && CpuSimulate && (i < STEPS_PER_CYCLE); i++)
     {
         EmulatorStep();
 #ifdef IPS_DISPLAY

Modified: branches/ntvdm/subsystems/ntvdm/emulator.c
URL: http://svn.reactos.org/svn/reactos/branches/ntvdm/subsystems/ntvdm/emulator....
==============================================================================
--- branches/ntvdm/subsystems/ntvdm/emulator.c	[iso-8859-1] (original)
+++ branches/ntvdm/subsystems/ntvdm/emulator.c	[iso-8859-1] Sun Feb 23 15:54:20 2014
@@ -30,6 +30,12 @@
 /* PRIVATE VARIABLES **********************************************************/

FAST486_STATE EmulatorContext;
+BOOLEAN CpuSimulate = FALSE;
+
+/* No more than 'MaxCpuCallLevel' recursive CPU calls are allowed */
+const static INT MaxCpuCallLevel = 32;
+static INT CpuCallLevel = 0;
+
 LPVOID  BaseAddress = NULL;
 BOOLEAN VdmRunning  = TRUE;

@@ -177,18 +183,31 @@

VOID EmulatorSimulate(VOID)
 {
-    // FIXME: Do not mix VdmRunning (i.e. ntvdm running) and CpuSimulate!!
-    while (VdmRunning) ClockUpdate();
+    if (CpuCallLevel > MaxCpuCallLevel)
+    {
+        DisplayMessage(L"Too many CPU levels of recursion (%d, expected maximum %d)",
+                       CpuCallLevel, MaxCpuCallLevel);
+
+        /* Stop the VDM */
+        VdmRunning = FALSE;
+        return;
+    }
+    CpuCallLevel++;
+
+    CpuSimulate = TRUE;
+    while (VdmRunning && CpuSimulate) ClockUpdate();
+
+    CpuCallLevel--;
+    if (CpuCallLevel < 0) CpuCallLevel = 0;

/* This takes into account for reentrance */
-    VdmRunning = TRUE;
+    CpuSimulate = TRUE;
 }

VOID EmulatorUnsimulate(VOID)
 {
     /* Stop simulation */
-    // FIXME: Do not mix VdmRunning (i.e. ntvdm running) and CpuSimulate!!
-    VdmRunning = FALSE;
+    CpuSimulate = FALSE;
 }

VOID EmulatorInterrupt(BYTE Number)