PCHAR MiProtectionToString[] = {
"MM_ZERO_ACCESS", // 0 // this value is not used.
"MM_READONLY", // 1
"MM_EXECUTE", // 2
"MM_EXECUTE_READ", // 3
"MM_READWRITE", // 4 // bit 2 is set if this is writable.
"MM_WRITECOPY", // 5
"MM_EXECUTE_READWRITE", // 6
"MM_EXECUTE_WRITECOPY", // 7
"MM_NOCACHE" // 8
};

#if 1
#undef MmPrint
#define MmPrint(x)
#endif

VALIDITY_CHECK_STATUS
MmIsAddressValidExNotPae(
IN PVOID Pointer
)
{
VALIDITY_CHECK_STATUS Return = VCS_INVALID;


MMPTE* Pde = MiGetPdeAddress(Pointer);

MmPrint(("PDE is 0x%08x\n", Pde));
if( Pde->u.Hard.Valid )
{
MmPrint(("PDE entry is valid, PTE PFN=%08x\n", Pde->u.Hard.PageFrameNumber));

MMPTE* Pte = MiGetPteAddress(Pointer);

MmPrint(("PTE is 0x%08x\n", Pte));
if( Pte->u.Hard.Valid )
{
MmPrint(("PTE entry is valid, PFN=%08x\n", Pte->u.Hard.PageFrameNumber));
Return = VCS_VALID;
}
else
{
//
// PTE is not valid
//

MMPTE pte = *Pte;

MmPrint(("Got invalid PTE [%08x]: Proto=%d,Transition=%d,Protection=0x%x,PageFilePFN=0x%x\n",
pte.u.Long,
pte.u.Soft.Prototype,
pte.u.Soft.Transition,
pte.u.Soft.Protection,
pte.u.Soft.PageFileHigh));

if( pte.u.Long )
{
if( pte.u.Soft.Prototype == 1 )
{
MmPrint(("PTE entry is not valid, points to prototype PTE.\n"));

// more accurate check should be performed here for pointed prototype PTE!

Return = VCS_PROTOTYPE;
}
else // not a prototype PTE
{
if( pte.u.Soft.Transition != 0 )
{
//
// This is a transition page. Consider it invalid.
//

MmPrint(("PTE entry is not valid, points to transition page.\n"));

Return = VCS_TRANSITION;
}
else if (pte.u.Soft.PageFileHigh == 0)
{
//
// Demand zero page
//

MmPrint(("PTE entry is not valid, points to demand-zero page.\n"));

Return = VCS_DEMANDZERO;
}
else
{
//
// Pagefile PTE
//

if( pte.u.Soft.Transition == 0 )
{
MmPrint(("PTE entry is not valid, VA is paged out (PageFile offset=%08x)\n",
pte.u.Soft.PageFileHigh));

Return = VCS_PAGEDOUT;
}
else
{
MmPrint(("PTE entry is not valid, Refault\n"));
}
}
}
}
else
{
MmPrint(("PTE entry is completely invalid\n"));
}
}
}
else
{
MmPrint(("PDE entry is not valid\n"));
}

return Return;
}


VALIDITY_CHECK_STATUS
MmIsAddressValidExPae(
IN PVOID Pointer
)
{
VALIDITY_CHECK_STATUS Return = VCS_INVALID;

MMPTE_PAE* Pde = MiGetPdeAddressPae(Pointer);

MmPrint(("PDE is at 0x%08x\n", Pde));
if( Pde->u.Hard.Valid )
{
MmPrint(("PDE entry is valid, PTE PFN=%08x\n", Pde->u.Hard.PageFrameNumber));

MMPTE_PAE* Pte;

if( Pde->u.Hard.LargePage != 0 )
{
//
// This is a large 2M page
//

MmPrint(("! PDE points to large 2M page\n"));

Pte = Pde;
}
else
{
//
// Small 4K page
//

// Get its PTE
Pte = MiGetPteAddressPae(Pointer);
}

MmPrint(("PTE is at 0x%08x\n", Pte));
if( Pte->u.Hard.Valid )
{
MmPrint(("PTE entry is valid, PFN=%08x\n", Pte->u.Hard.PageFrameNumber));

Return = VCS_VALID;
}
else
{
//
// PTE is not valid
//

MMPTE_PAE pte = *Pte;

MmPrint(("Got invalid PTE [%08x%08x]\n", pte.u.Long.HighPart, pte.u.Long.LowPart));

if( pte.u.Long.LowPart == 0 )
{
MmPrint(("PTE entry is completely invalid (page is not committed or is within VAD tree)\n"));
}
else
{
if( pte.u.Soft.Prototype == 1 )
{
MmPrint(("PTE entry is not valid, points to prototype PTE. Protection=%x[%s], ProtoAddress=%x\n",
(ULONG)pte.u.Proto.Protection,
MiPageProtectionString((UCHAR)pte.u.Proto.Protection),
(ULONG)pte.u.Proto.ProtoAddress));

// more accurate check should be performed here for pointed prototype PTE!

Return = VCS_PROTOTYPE;
}
else // not a prototype PTE
{
if( pte.u.Soft.Transition != 0 )
{
//
// This is a transition page.
//

MmPrint(("PTE entry is not valid, points to transition page. PFN=%x, Protection=%x[%s]\n",
(ULONG)pte.u.Trans.PageFrameNumber,
(ULONG)pte.u.Trans.Protection,
MiPageProtectionString((UCHAR)pte.u.Trans.Protection)));

Return = VCS_TRANSITION;
}
else if (pte.u.Soft.PageFileHigh == 0)
{
//
// Demand zero page
//

MmPrint(("PTE entry is not valid, points to demand-zero page. Protection=%x[%s]\n",
(ULONG)pte.u.Soft.Protection,
MiPageProtectionString((UCHAR)pte.u.Soft.Protection)));

Return = VCS_DEMANDZERO;
}
else
{
//
// Pagefile PTE
//

if( pte.u.Soft.Transition == 0 )
{
MmPrint(("PTE entry is not valid, VA is paged out. PageFile Offset=%08x, Protection=%x[%s]\n",
(ULONG)pte.u.Soft.PageFileHigh,
(ULONG)pte.u.Soft.Protection,
MiPageProtectionString((UCHAR)pte.u.Soft.Protection)));

Return = VCS_PAGEDOUT;
}
else
{
MmPrint(("PTE entry is not valid, Refault\n"));
}
}
}
}
}
}
else
{
MmPrint(("PDE entry is not valid\n"));
}

return Return;
}

VALIDITY_CHECK_STATUS
MmIsAddressValidEx(
IN PVOID Pointer
)
{
if( CR4() & PAE_ON ) {
return MmIsAddressValidExPae(Pointer);
}
else {
return MmIsAddressValidExNotPae(Pointer);
}
}


BOOLEAN
MmIsAddressRangeValid(
IN PVOID Address,
IN ULONG Size
)
{
Address = ALIGN_DOWN_POINTER(Address, PAGE_SIZE);
Size = ALIGN_UP(Size, PAGE_SIZE);

for( PVOID Ptr = Address; (ULONG)Ptr < (ULONG)Address + Size; *(ULONG*)&Ptr += PAGE_SIZE )
{
if( MmIsAddressValidEx(Ptr) == VCS_INVALID ) {
return FALSE;
}
}

return TRUE;
}