[aandrejevic] 60903: [NTVDM] Make the emulator callbacks non-static. In BiosPrintCallback, use EmulatorWriteMemory instead of VgaWriteMemory, because VgaWriteMemory does not do any input validation...

Author: aandrejevic
Date: Sat Nov  9 17:16:04 2013
New Revision: 60903

URL: http://svn.reactos.org/svn/reactos?rev=60903&view=rev
Log:
[NTVDM]
Make the emulator callbacks non-static.
In BiosPrintCallback, use EmulatorWriteMemory instead of VgaWriteMemory, because
VgaWriteMemory does not do any input validation.
Improve EmulatorWriteMemory input validation and bound checking.


Modified:
    branches/ntvdm/subsystems/ntvdm/bios.c
    branches/ntvdm/subsystems/ntvdm/emulator.c
    branches/ntvdm/subsystems/ntvdm/emulator.h

Modified: branches/ntvdm/subsystems/ntvdm/bios.c
URL:
http://svn.reactos.org/svn/reactos/branches/ntvdm/subsystems/ntvdm/bios.c?r…
==============================================================================
--- branches/ntvdm/subsystems/ntvdm/bios.c	[iso-8859-1] (original)
+++ branches/ntvdm/subsystems/ntvdm/bios.c	[iso-8859-1] Sat Nov  9 17:16:04 2013
@@ -760,11 +760,12 @@
         /* Default character */
 
         /* Write the character */
-        VgaWriteMemory(TO_LINEAR(TEXT_VIDEO_SEG,
-                       Page * Bda->VideoPageSize
-                       + (Row * Bda->ScreenColumns + Column) * sizeof(WORD)),
-                       (LPVOID)&CharData,
-                       sizeof(WORD));
+        EmulatorWriteMemory(&EmulatorContext,
+                            TO_LINEAR(TEXT_VIDEO_SEG,
+                            Page * Bda->VideoPageSize
+                            + (Row * Bda->ScreenColumns + Column) * sizeof(WORD)),
+                            (LPVOID)&CharData,
+                            sizeof(WORD));
 
         /* Advance the cursor */
         Column++;
@@ -789,6 +790,8 @@
                          Rectangle,
                          Page,
                          DEFAULT_ATTRIBUTE);
+
+        Row--;
     }
 
     /* Set the cursor position */

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] Sat Nov  9 17:16:04 2013
@@ -29,7 +29,7 @@
 
 /* PRIVATE FUNCTIONS **********************************************************/
 
-static VOID WINAPI EmulatorReadMemory(PFAST486_STATE State, ULONG Address, PVOID Buffer,
ULONG Size)
+VOID WINAPI EmulatorReadMemory(PFAST486_STATE State, ULONG Address, PVOID Buffer, ULONG
Size)
 {
     UNREFERENCED_PARAMETER(State);
 
@@ -47,14 +47,16 @@
         && (Address < VgaGetVideoLimitAddress()))
     {
         DWORD VgaAddress = max(Address, VgaGetVideoBaseAddress());
+        DWORD ActualSize = min(Address + Size - 1, VgaGetVideoLimitAddress())
+                           - VgaAddress + 1;
         LPBYTE VgaBuffer = (LPBYTE)((ULONG_PTR)Buffer + VgaAddress - Address);
 
         /* Read from the VGA memory */
-        VgaReadMemory(VgaAddress, VgaBuffer, Size);
-    }
-}
-
-static VOID WINAPI EmulatorWriteMemory(PFAST486_STATE State, ULONG Address, PVOID Buffer,
ULONG Size)
+        VgaReadMemory(VgaAddress, VgaBuffer, ActualSize);
+    }
+}
+
+VOID WINAPI EmulatorWriteMemory(PFAST486_STATE State, ULONG Address, PVOID Buffer, ULONG
Size)
 {
     UNREFERENCED_PARAMETER(State);
 
@@ -75,14 +77,16 @@
         && (Address < VgaGetVideoLimitAddress()))
     {
         DWORD VgaAddress = max(Address, VgaGetVideoBaseAddress());
+        DWORD ActualSize = min(Address + Size - 1, VgaGetVideoLimitAddress())
+                           - VgaAddress + 1;
         LPBYTE VgaBuffer = (LPBYTE)((ULONG_PTR)Buffer + VgaAddress - Address);
 
         /* Write to the VGA memory */
-        VgaWriteMemory(VgaAddress, VgaBuffer, Size);
-    }
-}
-
-static VOID WINAPI EmulatorReadIo(PFAST486_STATE State, ULONG Port, PVOID Buffer, ULONG
DataCount, UCHAR DataSize)
+        VgaWriteMemory(VgaAddress, VgaBuffer, ActualSize);
+    }
+}
+
+VOID WINAPI EmulatorReadIo(PFAST486_STATE State, ULONG Port, PVOID Buffer, ULONG
DataCount, UCHAR DataSize)
 {
     INT i, j;
     LPBYTE Address = (LPBYTE)Buffer;
@@ -169,7 +173,7 @@
     }
 }
 
-static VOID WINAPI EmulatorWriteIo(PFAST486_STATE State, ULONG Port, PVOID Buffer, ULONG
DataCount, UCHAR DataSize)
+VOID WINAPI EmulatorWriteIo(PFAST486_STATE State, ULONG Port, PVOID Buffer, ULONG
DataCount, UCHAR DataSize)
 {
     INT i, j;
     LPBYTE Address = (LPBYTE)Buffer;
@@ -268,7 +272,7 @@
     }
 }
 
-static VOID WINAPI EmulatorBiosOperation(PFAST486_STATE State, UCHAR BopCode)
+VOID WINAPI EmulatorBiosOperation(PFAST486_STATE State, UCHAR BopCode)
 {
     WORD StackSegment, StackPointer;
     LPWORD Stack;
@@ -286,7 +290,7 @@
         DPRINT1("Invalid BOP code %u\n", BopCode);
 }
 
-static UCHAR WINAPI EmulatorIntAcknowledge(PFAST486_STATE State)
+UCHAR WINAPI EmulatorIntAcknowledge(PFAST486_STATE State)
 {
     UNREFERENCED_PARAMETER(State);
 

Modified: branches/ntvdm/subsystems/ntvdm/emulator.h
URL:
http://svn.reactos.org/svn/reactos/branches/ntvdm/subsystems/ntvdm/emulator…
==============================================================================
--- branches/ntvdm/subsystems/ntvdm/emulator.h	[iso-8859-1] (original)
+++ branches/ntvdm/subsystems/ntvdm/emulator.h	[iso-8859-1] Sat Nov  9 17:16:04 2013
@@ -86,6 +86,51 @@
 
 /* FUNCTIONS ******************************************************************/
 
+VOID WINAPI EmulatorReadMemory
+(
+    PFAST486_STATE State,
+    ULONG Address,
+    PVOID Buffer,
+    ULONG Size
+);
+
+VOID WINAPI EmulatorWriteMemory
+(
+    PFAST486_STATE State,
+    ULONG Address,
+    PVOID Buffer,
+    ULONG Size
+);
+
+VOID WINAPI EmulatorReadIo
+(
+    PFAST486_STATE State,
+    ULONG Port,
+    PVOID Buffer,
+    ULONG DataCount,
+    UCHAR DataSize
+);
+
+VOID WINAPI EmulatorWriteIo
+(
+    PFAST486_STATE State,
+    ULONG Port,
+    PVOID Buffer,
+    ULONG DataCount,
+    UCHAR DataSize
+);
+
+VOID WINAPI EmulatorBiosOperation
+(
+    PFAST486_STATE State,
+    UCHAR BopCode
+);
+
+UCHAR WINAPI EmulatorIntAcknowledge
+(
+    PFAST486_STATE State
+);
+
 BOOLEAN EmulatorInitialize(VOID);
 VOID EmulatorSetStack(WORD Segment, DWORD Offset);
 VOID EmulatorExecute(WORD Segment, WORD Offset);