/*
* @implemented
*/
BOOLEAN
NTAPI
MmIsAddressValid(IN PVOID VirtualAddress)
{
#if _MI_PAGING_LEVELS >= 4
/* Check if the PXE is valid */
if (MiAddressToPxe(VirtualAddress)->u.Hard.Valid == 0) return FALSE;
#endif
#if _MI_PAGING_LEVELS >= 3
/* Check if the PPE is valid */
if (MiAddressToPpe(VirtualAddress)->u.Hard.Valid == 0) return FALSE;
#endif
#if _MI_PAGING_LEVELS >= 2
/* Check if the PDE is valid */
if (MiAddressToPde(VirtualAddress)->u.Hard.Valid == 0) return FALSE;
#endif
/* Check if the PTE is valid */
if (MiAddressToPte(VirtualAddress)->u.Hard.Valid == 0) return FALSE;
/* This address is valid now, but it will only stay so if the caller holds
* the PFN lock */
return TRUE;
}
EXTERN_C static
bool Win8pIsAccessibleAddress(
__in void* Address)
{
PAGED_CODE();
const auto pxe = MiAddressToPxe(Address);
const auto ppe = MiAddressToPpe(Address);
const auto pde = MiAddressToPde(Address);
const auto pte = MiAddressToPte(Address);
if ((!pxe->Valid) ||
(!ppe->Valid) ||
(!pde->Valid) ||
(!pde->LargePage && (!pte || !pte->Valid)))
{
return false;
}
return true;
}
/*
* @implemented
*/
VOID
NTAPI
MmProbeAndLockPages(IN PMDL Mdl,
IN KPROCESSOR_MODE AccessMode,
IN LOCK_OPERATION Operation)
{
PPFN_NUMBER MdlPages;
PVOID Base, Address, LastAddress, StartAddress;
ULONG LockPages, TotalPages;
NTSTATUS Status = STATUS_SUCCESS;
PEPROCESS CurrentProcess;
NTSTATUS ProbeStatus;
PMMPTE PointerPte, LastPte;
PMMPDE PointerPde;
#if (_MI_PAGING_LEVELS >= 3)
PMMPDE PointerPpe;
#endif
#if (_MI_PAGING_LEVELS == 4)
PMMPDE PointerPxe;
#endif
PFN_NUMBER PageFrameIndex;
BOOLEAN UsePfnLock;
KIRQL OldIrql;
PMMPFN Pfn1;
DPRINT("Probing MDL: %p\n", Mdl);
//
// Sanity checks
//
ASSERT(Mdl->ByteCount != 0);
ASSERT(((ULONG)Mdl->ByteOffset & ~(PAGE_SIZE - 1)) == 0);
ASSERT(((ULONG_PTR)Mdl->StartVa & (PAGE_SIZE - 1)) == 0);
ASSERT((Mdl->MdlFlags & (MDL_PAGES_LOCKED |
MDL_MAPPED_TO_SYSTEM_VA |
MDL_SOURCE_IS_NONPAGED_POOL |
MDL_PARTIAL |
MDL_IO_SPACE)) == 0);
//
// Get page and base information
//
MdlPages = (PPFN_NUMBER)(Mdl + 1);
Base = Mdl->StartVa;
//
// Get the addresses and how many pages we span (and need to lock)
//
Address = (PVOID)((ULONG_PTR)Base + Mdl->ByteOffset);
LastAddress = (PVOID)((ULONG_PTR)Address + Mdl->ByteCount);
LockPages = ADDRESS_AND_SIZE_TO_SPAN_PAGES(Address, Mdl->ByteCount);
ASSERT(LockPages != 0);
/* Block invalid access */
if ((AccessMode != KernelMode) &&
((LastAddress > (PVOID)MM_USER_PROBE_ADDRESS) || (Address >= LastAddress)))
{
/* Caller should be in SEH, raise the error */
*MdlPages = LIST_HEAD;
ExRaiseStatus(STATUS_ACCESS_VIOLATION);
}
//
// Get the process
//
if (Address <= MM_HIGHEST_USER_ADDRESS)
{
//
// Get the process
//
CurrentProcess = PsGetCurrentProcess();
}
else
{
//
// No process
//
CurrentProcess = NULL;
}
//
// Save the number of pages we'll have to lock, and the start address
//
TotalPages = LockPages;
StartAddress = Address;
/* Large pages not supported */
ASSERT(!MI_IS_PHYSICAL_ADDRESS(Address));
//
// Now probe them
//
ProbeStatus = STATUS_SUCCESS;
_SEH2_TRY
{
//
// Enter probe loop
//
do
{
//
// Assume failure
//
*MdlPages = LIST_HEAD;
//
// Read
//
*(volatile CHAR*)Address;
//
// Check if this is write access (only probe for user-mode)
//
if ((Operation != IoReadAccess) &&
(Address <= MM_HIGHEST_USER_ADDRESS))
{
//
// Probe for write too
//
ProbeForWriteChar(Address);
}
//
// Next address...
//
Address = PAGE_ALIGN((ULONG_PTR)Address + PAGE_SIZE);
//
// Next page...
//
LockPages--;
MdlPages++;
} while (Address < LastAddress);
//
// Reset back to the original page
//
ASSERT(LockPages == 0);
MdlPages = (PPFN_NUMBER)(Mdl + 1);
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
//
// Oops :(
//
ProbeStatus = _SEH2_GetExceptionCode();
}
_SEH2_END;
//
// So how did that go?
//
if (ProbeStatus != STATUS_SUCCESS)
{
//
// Fail
//
DPRINT1("MDL PROBE FAILED!\n");
Mdl->Process = NULL;
ExRaiseStatus(ProbeStatus);
}
//
// Get the PTE and PDE
//
PointerPte = MiAddressToPte(StartAddress);
PointerPde = MiAddressToPde(StartAddress);
#if (_MI_PAGING_LEVELS >= 3)
PointerPpe = MiAddressToPpe(StartAddress);
#endif
#if (_MI_PAGING_LEVELS == 4)
PointerPxe = MiAddressToPxe(StartAddress);
#endif
//
// Sanity check
//
ASSERT(MdlPages == (PPFN_NUMBER)(Mdl + 1));
//
// Check what kind of operation this is
//
if (Operation != IoReadAccess)
{
//
// Set the write flag
//
Mdl->MdlFlags |= MDL_WRITE_OPERATION;
}
else
{
//
// Remove the write flag
//
Mdl->MdlFlags &= ~(MDL_WRITE_OPERATION);
}
//
// Mark the MDL as locked *now*
//
Mdl->MdlFlags |= MDL_PAGES_LOCKED;
//
// Check if this came from kernel mode
//
if (Base > MM_HIGHEST_USER_ADDRESS)
{
//
// We should not have a process
//
ASSERT(CurrentProcess == NULL);
Mdl->Process = NULL;
//
// In kernel mode, we don't need to check for write access
//
Operation = IoReadAccess;
//
// Use the PFN lock
//
UsePfnLock = TRUE;
OldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
}
else
{
//
// Sanity checks
//
ASSERT(TotalPages != 0);
ASSERT(CurrentProcess == PsGetCurrentProcess());
//
// Track locked pages
//
InterlockedExchangeAddSizeT(&CurrentProcess->NumberOfLockedPages,
TotalPages);
//
// Save the process
//
Mdl->Process = CurrentProcess;
/* Lock the process working set */
MiLockProcessWorkingSet(CurrentProcess, PsGetCurrentThread());
UsePfnLock = FALSE;
OldIrql = MM_NOIRQL;
}
//
// Get the last PTE
//
LastPte = MiAddressToPte((PVOID)((ULONG_PTR)LastAddress - 1));
//
// Loop the pages
//
do
{
//
// Assume failure and check for non-mapped pages
//
*MdlPages = LIST_HEAD;
while (
#if (_MI_PAGING_LEVELS == 4)
(PointerPxe->u.Hard.Valid == 0) ||
#endif
#if (_MI_PAGING_LEVELS >= 3)
(PointerPpe->u.Hard.Valid == 0) ||
#endif
(PointerPde->u.Hard.Valid == 0) ||
(PointerPte->u.Hard.Valid == 0))
{
//
// What kind of lock were we using?
//
if (UsePfnLock)
{
//
// Release PFN lock
//
KeReleaseQueuedSpinLock(LockQueuePfnLock, OldIrql);
}
else
{
/* Release process working set */
MiUnlockProcessWorkingSet(CurrentProcess, PsGetCurrentThread());
}
//
// Access the page
//
Address = MiPteToAddress(PointerPte);
//HACK: Pass a placeholder TrapInformation so the fault handler knows we're unlocked
Status = MmAccessFault(FALSE, Address, KernelMode, (PVOID)0xBADBADA3);
if (!NT_SUCCESS(Status))
{
//
// Fail
//
DPRINT1("Access fault failed\n");
goto Cleanup;
}
//
// What lock should we use?
//
if (UsePfnLock)
{
//
// Grab the PFN lock
//
OldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
}
else
{
/* Lock the process working set */
MiLockProcessWorkingSet(CurrentProcess, PsGetCurrentThread());
}
}
//
// Check if this was a write or modify
//
if (Operation != IoReadAccess)
{
//
// Check if the PTE is not writable
//
if (MI_IS_PAGE_WRITEABLE(PointerPte) == FALSE)
{
//
// Check if it's copy on write
//
if (MI_IS_PAGE_COPY_ON_WRITE(PointerPte))
{
//
// Get the base address and allow a change for user-mode
//
Address = MiPteToAddress(PointerPte);
if (Address <= MM_HIGHEST_USER_ADDRESS)
{
//
// What kind of lock were we using?
//
if (UsePfnLock)
{
//
// Release PFN lock
//
KeReleaseQueuedSpinLock(LockQueuePfnLock, OldIrql);
}
else
{
/* Release process working set */
MiUnlockProcessWorkingSet(CurrentProcess, PsGetCurrentThread());
}
//
// Access the page
//
//HACK: Pass a placeholder TrapInformation so the fault handler knows we're unlocked
Status = MmAccessFault(TRUE, Address, KernelMode, (PVOID)0xBADBADA3);
if (!NT_SUCCESS(Status))
{
//
// Fail
//
DPRINT1("Access fault failed\n");
goto Cleanup;
}
//
// Re-acquire the lock
//
if (UsePfnLock)
{
//
// Grab the PFN lock
//
OldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
}
else
{
/* Lock the process working set */
MiLockProcessWorkingSet(CurrentProcess, PsGetCurrentThread());
}
//
// Start over
//
continue;
}
}
//
// Fail, since we won't allow this
//
Status = STATUS_ACCESS_VIOLATION;
goto CleanupWithLock;
}
}
//
// Grab the PFN
//
PageFrameIndex = PFN_FROM_PTE(PointerPte);
Pfn1 = MiGetPfnEntry(PageFrameIndex);
if (Pfn1)
{
/* Either this is for kernel-mode, or the working set is held */
ASSERT((CurrentProcess == NULL) || (UsePfnLock == FALSE));
/* No Physical VADs supported yet */
if (CurrentProcess) ASSERT(CurrentProcess->PhysicalVadRoot == NULL);
/* This address should already exist and be fully valid */
MiReferenceProbedPageAndBumpLockCount(Pfn1);
}
else
{
//
// For I/O addresses, just remember this
//
Mdl->MdlFlags |= MDL_IO_SPACE;
}
//
// Write the page and move on
//
*MdlPages++ = PageFrameIndex;
PointerPte++;
/* Check if we're on a PDE boundary */
if (MiIsPteOnPdeBoundary(PointerPte)) PointerPde++;
#if (_MI_PAGING_LEVELS >= 3)
if (MiIsPteOnPpeBoundary(PointerPte)) PointerPpe++;
#endif
#if (_MI_PAGING_LEVELS == 4)
if (MiIsPteOnPxeBoundary(PointerPte)) PointerPxe++;
#endif
} while (PointerPte <= LastPte);
//
// What kind of lock were we using?
//
if (UsePfnLock)
{
//
// Release PFN lock
//
KeReleaseQueuedSpinLock(LockQueuePfnLock, OldIrql);
}
else
{
/* Release process working set */
MiUnlockProcessWorkingSet(CurrentProcess, PsGetCurrentThread());
}
//
// Sanity check
//
ASSERT((Mdl->MdlFlags & MDL_DESCRIBES_AWE) == 0);
return;
CleanupWithLock:
//
// This is the failure path
//
ASSERT(!NT_SUCCESS(Status));
//
// What kind of lock were we using?
//
if (UsePfnLock)
{
//
// Release PFN lock
//
KeReleaseQueuedSpinLock(LockQueuePfnLock, OldIrql);
}
else
{
/* Release process working set */
MiUnlockProcessWorkingSet(CurrentProcess, PsGetCurrentThread());
}
Cleanup:
//
// Pages must be locked so MmUnlock can work
//
ASSERT(Mdl->MdlFlags & MDL_PAGES_LOCKED);
MmUnlockPages(Mdl);
//
// Raise the error
//
ExRaiseStatus(Status);
}
static
PMMPTE
MiGetPteForProcess(
PEPROCESS Process,
PVOID Address,
BOOLEAN Create)
{
MMPTE TmplPte, *Pte;
/* Check if we need hypersapce mapping */
if (Address < MmSystemRangeStart &&
Process && Process != PsGetCurrentProcess())
{
UNIMPLEMENTED;
__debugbreak();
return NULL;
}
else if (Create)
{
KIRQL OldIrql;
TmplPte.u.Long = 0;
TmplPte.u.Flush.Valid = 1;
TmplPte.u.Flush.Write = 1;
/* All page table levels of user pages are user owned */
TmplPte.u.Flush.Owner = (Address < MmHighestUserAddress) ? 1 : 0;
/* Lock the PFN database */
OldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
/* Get the PXE */
Pte = MiAddressToPxe(Address);
if (!Pte->u.Hard.Valid)
{
TmplPte.u.Hard.PageFrameNumber = MiRemoveZeroPage(0);
MI_WRITE_VALID_PTE(Pte, TmplPte);
}
/* Get the PPE */
Pte = MiAddressToPpe(Address);
if (!Pte->u.Hard.Valid)
{
TmplPte.u.Hard.PageFrameNumber = MiRemoveZeroPage(1);
MI_WRITE_VALID_PTE(Pte, TmplPte);
}
/* Get the PDE */
Pte = MiAddressToPde(Address);
if (!Pte->u.Hard.Valid)
{
TmplPte.u.Hard.PageFrameNumber = MiRemoveZeroPage(2);
MI_WRITE_VALID_PTE(Pte, TmplPte);
}
/* Unlock PFN database */
KeReleaseQueuedSpinLock(LockQueuePfnLock, OldIrql);
}
else
{
/* Get the PXE */
Pte = MiAddressToPxe(Address);
if (!Pte->u.Hard.Valid)
return NULL;
/* Get the PPE */
Pte = MiAddressToPpe(Address);
if (!Pte->u.Hard.Valid)
return NULL;
/* Get the PDE */
Pte = MiAddressToPde(Address);
if (!Pte->u.Hard.Valid)
return NULL;
}
return MiAddressToPte(Address);
}
