r1100 - trunk/code/qcommon

[DONOTREPLY at icculus.org]

Author: ludwig
Date: 2007-06-25 05:45:18 -0400 (Mon, 25 Jun 2007)
New Revision: 1100

Modified:
   trunk/code/qcommon/vm_interpreted.c
Log:
check program counter on OP_CALL and OP_LEAVE


Modified: trunk/code/qcommon/vm_interpreted.c
===================================================================
--- trunk/code/qcommon/vm_interpreted.c	2007-06-13 20:41:06 UTC (rev 1099)
+++ trunk/code/qcommon/vm_interpreted.c	2007-06-25 09:45:18 UTC (rev 1100)
@@ -394,9 +394,8 @@
 		r0 = ((int *)opStack)[0];
 		r1 = ((int *)opStack)[-1];
 nextInstruction2:
-		opcode = codeImage[ programCounter++ ];
 #ifdef DEBUG_VM
-		if ( (unsigned)programCounter > vm->codeLength ) {
+		if ( (unsigned)programCounter >= vm->codeLength ) {
 			Com_Error( ERR_DROP, "VM pc out of range" );
 		}
 
@@ -420,6 +419,7 @@
 		}
 		profileSymbol->profileCount++;
 #endif
+		opcode = codeImage[ programCounter++ ];
 
 		switch ( opcode ) {
 #ifdef DEBUG_VM
@@ -564,6 +564,8 @@
 					Com_Printf( "%s<--- %s\n", DEBUGSTR, VM_ValueToSymbol( vm, programCounter ) );
 				}
 #endif
+			} else if ( (unsigned)programCounter >= vm->codeLength ) {
+				Com_Error( ERR_DROP, "VM program counter out of range in OP_CALL" );
 			} else {
 				programCounter = vm->instructionPointers[ programCounter ];
 			}
@@ -619,6 +621,8 @@
 			// check for leaving the VM
 			if ( programCounter == -1 ) {
 				goto done;
+			} else if ( (unsigned)programCounter >= vm->codeLength ) {
+				Com_Error( ERR_DROP, "VM program counter out of range in OP_LEAVE" );
 			}
 			goto nextInstruction;