/* GLOBALS *******************************************************************/
/* Boot and double-fault/NMI/DPC stack */
-UCHAR DECLSPEC_ALIGN(16) P0BootStackData[KERNEL_STACK_SIZE] = {0};
-UCHAR DECLSPEC_ALIGN(16) KiDoubleFaultStackData[KERNEL_STACK_SIZE] = {0};
+UCHAR DECLSPEC_ALIGN(PAGE_SIZE) P0BootStackData[KERNEL_STACK_SIZE] = {0};
+UCHAR DECLSPEC_ALIGN(PAGE_SIZE) KiDoubleFaultStackData[KERNEL_STACK_SIZE] = {0};
ULONG_PTR P0BootStack = (ULONG_PTR)&P0BootStackData[KERNEL_STACK_SIZE];
ULONG_PTR KiDoubleFaultStack = (ULONG_PTR)&KiDoubleFaultStackData[KERNEL_STACK_SIZE];
KiIdleLoop();
}
+static
+VOID
+KiMarkPageAsReadOnly(
+ PVOID Address)
+{
+ PHARDWARE_PTE PointerPte;
+
+ /* Make sure the address is page aligned */
+ ASSERT(ALIGN_DOWN_POINTER_BY(Address, PAGE_SIZE) == Address);
+
+ /* Get the PTE address */
+ PointerPte = ((PHARDWARE_PTE)PTE_BASE) + ((ULONG_PTR)Address / PAGE_SIZE);
+ ASSERT(PointerPte->Valid);
+ ASSERT(PointerPte->Write);
+
+ /* Set as read-only */
+ PointerPte->Write = 0;
+
+ /* Flush the TLB entry */
+ __invlpg(Address);
+}
+
VOID
NTAPI
INIT_FUNCTION
/* Check for break-in */
if (KdPollBreakIn()) DbgBreakPointWithStatus(DBG_STATUS_CONTROL_C);
+
+ /* Make the lowest page of the boot and double fault stack read-only */
+ KiMarkPageAsReadOnly(P0BootStackData);
+ KiMarkPageAsReadOnly(KiDoubleFaultStackData);
}
/* Raise to HIGH_LEVEL */