mirror of https://github.com/tongzx/nt5src
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
826 lines
17 KiB
826 lines
17 KiB
/*++
|
|
|
|
Copyright (c) 2000 Microsoft Corporation
|
|
|
|
Module Name:
|
|
|
|
watchdog.c
|
|
|
|
Abstract:
|
|
|
|
This is the NT Watchdog driver implementation.
|
|
|
|
Author:
|
|
|
|
Michael Maciesowicz (mmacie) 05-May-2000
|
|
|
|
Environment:
|
|
|
|
Kernel mode only.
|
|
|
|
Notes:
|
|
|
|
Revision History:
|
|
|
|
--*/
|
|
|
|
#include "wd.h"
|
|
|
|
#ifdef ALLOC_PRAGMA
|
|
#pragma alloc_text (INIT, DriverEntry)
|
|
#pragma alloc_text (PAGE, WdAllocateWatchdog)
|
|
#endif
|
|
|
|
|
|
NTSTATUS
|
|
DriverEntry(
|
|
IN PDRIVER_OBJECT pDriverObject,
|
|
IN PUNICODE_STRING wszRegistryPath
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
Temporary entry point needed to initialize the watchdog driver.
|
|
This function is never called because we are loaded as a DLL
|
|
by other drivers.
|
|
|
|
Arguments:
|
|
|
|
pDriverObject - Not used.
|
|
wszRegistryPath - Not used.
|
|
|
|
Return Value:
|
|
|
|
STATUS_SUCCESS
|
|
|
|
--*/
|
|
|
|
{
|
|
UNREFERENCED_PARAMETER(pDriverObject);
|
|
UNREFERENCED_PARAMETER(wszRegistryPath);
|
|
ASSERT(FALSE);
|
|
|
|
return STATUS_SUCCESS;
|
|
} // DriverEntry()
|
|
|
|
WATCHDOGAPI
|
|
PWATCHDOG
|
|
WdAllocateWatchdog(
|
|
IN PDEVICE_OBJECT pDeviceObject,
|
|
IN WD_TIME_TYPE timeType,
|
|
IN ULONG ulTag
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This function allocates storage and initializes
|
|
a watchdog object.
|
|
|
|
Arguments:
|
|
|
|
pDeviceObject - Points to DEVICE_OBJECT associated with watchdog.
|
|
|
|
timeType - Kernel, User, Both thread time to monitor.
|
|
|
|
ulTag - A tag identifying owner.
|
|
|
|
Return Value:
|
|
|
|
Pointer to allocated watchdog object or NULL.
|
|
|
|
--*/
|
|
|
|
{
|
|
PWATCHDOG pWatch;
|
|
|
|
PAGED_CODE();
|
|
ASSERT((timeType >= WdKernelTime) && (timeType <= WdFullTime));
|
|
|
|
//
|
|
// Allocate storage for watchdog object from non-paged pool.
|
|
//
|
|
|
|
pWatch = (PWATCHDOG)ExAllocatePoolWithTag(NonPagedPool, sizeof (WATCHDOG), ulTag);
|
|
|
|
//
|
|
// Set initial state of watchdog object.
|
|
//
|
|
|
|
if (NULL != pWatch)
|
|
{
|
|
//
|
|
// Set initial state of watchdog.
|
|
//
|
|
|
|
WdInitializeObject(pWatch,
|
|
pDeviceObject,
|
|
WdStandardWatchdog,
|
|
timeType,
|
|
ulTag);
|
|
|
|
pWatch->StartCount = 0;
|
|
pWatch->SuspendCount = 0;
|
|
pWatch->LastKernelTime = 0;
|
|
pWatch->LastUserTime = 0;
|
|
pWatch->TimeIncrement = KeQueryTimeIncrement();
|
|
pWatch->DueTime.QuadPart = 0;
|
|
pWatch->InitialDueTime.QuadPart = 0;
|
|
pWatch->Thread = NULL;
|
|
pWatch->ClientDpc = NULL;
|
|
|
|
//
|
|
// Initialize encapsulated timer object.
|
|
//
|
|
|
|
KeInitializeTimerEx(&(pWatch->Timer), NotificationTimer);
|
|
|
|
//
|
|
// Initialize encapsulated DPC object.
|
|
//
|
|
|
|
KeInitializeDpc(&(pWatch->TimerDpc), WdWatchdogDpcCallback, pWatch);
|
|
}
|
|
|
|
return pWatch;
|
|
} // WdAllocateWatchdog()
|
|
|
|
WATCHDOGAPI
|
|
VOID
|
|
WdFreeWatchdog(
|
|
PWATCHDOG pWatch
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This function deallocates storage for watchdog object.
|
|
It will also stop started watchdog if needed.
|
|
|
|
Arguments:
|
|
|
|
pWatch - Supplies a pointer to a watchdog object.
|
|
|
|
Return Value:
|
|
|
|
None.
|
|
|
|
--*/
|
|
|
|
{
|
|
ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
|
|
ASSERT(NULL != pWatch);
|
|
ASSERT(pWatch->Header.ReferenceCount > 0);
|
|
|
|
//
|
|
// Stop watch just in case somebody forgot.
|
|
// If the watch is stopped already then this is a no-op.
|
|
//
|
|
|
|
WdStopWatch(pWatch, FALSE);
|
|
|
|
if (InterlockedDecrement(&(pWatch->Header.ReferenceCount)) == 0)
|
|
{
|
|
WdRemoveObject(pWatch);
|
|
}
|
|
|
|
return;
|
|
} // WdFreeWatchdog()
|
|
|
|
WATCHDOGAPI
|
|
VOID
|
|
WdStartWatch(
|
|
IN PWATCHDOG pWatch,
|
|
IN LARGE_INTEGER liDueTime,
|
|
IN PKDPC pDpc
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This function sets a watchdog to expire at a specified time. This
|
|
function also increments start count of the watchdog object, to allow
|
|
nested calls to Set / Cancel functions.
|
|
|
|
Note: To minimize an overhead it is caller's resposibility to make
|
|
sure thread remains valid when we are in the monitored section.
|
|
|
|
Arguments:
|
|
|
|
pWatch - Supplies a pointer to a watchdog object.
|
|
|
|
liDueTime - Supplies relative time at which the timer is to expire.
|
|
This time is in the 100ns units.
|
|
|
|
pDpc - Supplies a pointer to a control object of type DPC.
|
|
|
|
Return Value:
|
|
|
|
None.
|
|
|
|
--*/
|
|
|
|
{
|
|
PKTHREAD pThread;
|
|
KIRQL oldIrql;
|
|
|
|
ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
|
|
ASSERT(NULL != pWatch);
|
|
ASSERT(NULL != pDpc);
|
|
|
|
//
|
|
// Make sure we use a relative DueTime.
|
|
//
|
|
|
|
if (liDueTime.QuadPart > 0)
|
|
{
|
|
liDueTime.QuadPart = -liDueTime.QuadPart;
|
|
}
|
|
|
|
//
|
|
// Raise IRQL to dispatcher level and lock dispatcher database.
|
|
//
|
|
|
|
KeAcquireSpinLock(&(pWatch->Header.SpinLock), &oldIrql);
|
|
|
|
WD_DBG_SUSPENDED_WARNING(pWatch, "WdStartWatch");
|
|
|
|
if (pWatch->StartCount < (ULONG)(-1))
|
|
{
|
|
pWatch->StartCount++;
|
|
}
|
|
else
|
|
{
|
|
ASSERT(FALSE);
|
|
}
|
|
|
|
//
|
|
// We shouldn't hot swap DPCs without stopping first.
|
|
//
|
|
|
|
ASSERT((NULL == pWatch->ClientDpc) || (pDpc == pWatch->ClientDpc));
|
|
|
|
pThread = KeGetCurrentThread();
|
|
|
|
//
|
|
// We shouldn't swap threads in the monitored section.
|
|
//
|
|
|
|
ASSERT((pWatch->StartCount == 1) || (pThread == pWatch->Thread));
|
|
|
|
pWatch->Thread = pThread;
|
|
pWatch->ClientDpc = pDpc;
|
|
pWatch->DueTime.QuadPart = liDueTime.QuadPart;
|
|
pWatch->InitialDueTime.QuadPart = liDueTime.QuadPart;
|
|
pWatch->LastKernelTime = KeQueryRuntimeThread(pThread, &(pWatch->LastUserTime));
|
|
|
|
//
|
|
// Make sure ULONG counters won't overflow.
|
|
//
|
|
|
|
if (liDueTime.QuadPart < -WD_MAX_WAIT)
|
|
{
|
|
liDueTime.QuadPart = -WD_MAX_WAIT;
|
|
}
|
|
|
|
if (0 == pWatch->SuspendCount)
|
|
{
|
|
KeSetTimerEx(&(pWatch->Timer), liDueTime, 0, &(pWatch->TimerDpc));
|
|
}
|
|
|
|
//
|
|
// Unlock the dispatcher database and lower IRQL to its previous value.
|
|
//
|
|
|
|
KeReleaseSpinLock(&(pWatch->Header.SpinLock), oldIrql);
|
|
|
|
return;
|
|
} // WdStartWatch()
|
|
|
|
WATCHDOGAPI
|
|
VOID
|
|
WdStopWatch(
|
|
IN PWATCHDOG pWatch,
|
|
IN BOOLEAN bIncremental
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This function cancels a watchdog that was previously set to expire
|
|
at a specified time. If the watchdog is not currently set, then
|
|
no operation is performed.
|
|
|
|
Arguments:
|
|
|
|
pWatch - Supplies a pointer to a watchdog object.
|
|
|
|
bIncremental - If TRUE the watchdog will be cancelled only when
|
|
ReferenceCounter reaches 0, if FALSE watchdog is cancelled
|
|
immediately and ReferenceCounter is forced to 0.
|
|
|
|
Return Value:
|
|
|
|
None.
|
|
|
|
--*/
|
|
|
|
{
|
|
KIRQL oldIrql;
|
|
|
|
ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
|
|
ASSERT(NULL != pWatch);
|
|
|
|
//
|
|
// Raise IRQL to dispatcher level and lock dispatcher database.
|
|
//
|
|
|
|
KeAcquireSpinLock(&(pWatch->Header.SpinLock), &oldIrql);
|
|
|
|
WD_DBG_SUSPENDED_WARNING(pWatch, "WdStopWatch");
|
|
|
|
if (pWatch->StartCount > 0)
|
|
{
|
|
if (TRUE == bIncremental)
|
|
{
|
|
pWatch->StartCount--;
|
|
}
|
|
else
|
|
{
|
|
pWatch->StartCount = 0;
|
|
}
|
|
|
|
if (0 == pWatch->StartCount)
|
|
{
|
|
//
|
|
// Cancel encapsulated timer object.
|
|
//
|
|
|
|
KeCancelTimer(&(pWatch->Timer));
|
|
|
|
//
|
|
// Make sure we don't have client's DPC pending.
|
|
//
|
|
|
|
if (NULL != pWatch->ClientDpc)
|
|
{
|
|
if (KeRemoveQueueDpc(pWatch->ClientDpc) == TRUE)
|
|
{
|
|
//
|
|
// Was in queue - call WdCompleteEvent() here since DPC won't be delivered.
|
|
//
|
|
|
|
WdCompleteEvent(pWatch, pWatch->Header.LastQueuedThread);
|
|
}
|
|
}
|
|
|
|
//
|
|
// Set initial state of timer per thread.
|
|
//
|
|
|
|
pWatch->LastKernelTime = 0;
|
|
pWatch->LastUserTime = 0;
|
|
pWatch->DueTime.QuadPart = 0;
|
|
pWatch->InitialDueTime.QuadPart = 0;
|
|
pWatch->Thread = NULL;
|
|
pWatch->ClientDpc = NULL;
|
|
pWatch->Header.LastEvent = WdNoEvent;
|
|
pWatch->Header.LastQueuedThread = NULL;
|
|
}
|
|
}
|
|
|
|
//
|
|
// Unlock the dispatcher database and lower IRQL to its previous value.
|
|
//
|
|
|
|
KeReleaseSpinLock(&(pWatch->Header.SpinLock), oldIrql);
|
|
|
|
return;
|
|
} // WdStopWatch()
|
|
|
|
WATCHDOGAPI
|
|
VOID
|
|
WdSuspendWatch(
|
|
IN PWATCHDOG pWatch
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This function suspends watchdog.
|
|
|
|
Arguments:
|
|
|
|
pWatch - Supplies a pointer to a watchdog object.
|
|
|
|
Return Value:
|
|
|
|
None.
|
|
|
|
--*/
|
|
|
|
{
|
|
KIRQL oldIrql;
|
|
|
|
ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
|
|
ASSERT(NULL != pWatch);
|
|
|
|
//
|
|
// Raise IRQL to dispatcher level and lock dispatcher database.
|
|
//
|
|
|
|
KeAcquireSpinLock(&(pWatch->Header.SpinLock), &oldIrql);
|
|
|
|
ASSERT(pWatch->SuspendCount < (ULONG)(-1));
|
|
|
|
//
|
|
// If we are suspended for the first time and we have timer running
|
|
// we havo to stop a timer.
|
|
//
|
|
|
|
if ((0 == pWatch->SuspendCount) && pWatch->StartCount)
|
|
{
|
|
KeCancelTimer(&(pWatch->Timer));
|
|
}
|
|
|
|
pWatch->SuspendCount++;
|
|
|
|
//
|
|
// Unlock the dispatcher database and lower IRQL to its previous value.
|
|
//
|
|
|
|
KeReleaseSpinLock(&(pWatch->Header.SpinLock), oldIrql);
|
|
|
|
return;
|
|
} // WdSuspendWatch()
|
|
|
|
WATCHDOGAPI
|
|
VOID
|
|
WdResumeWatch(
|
|
IN PWATCHDOG pWatch,
|
|
IN BOOLEAN bIncremental
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This function resumes watchdog.
|
|
|
|
Arguments:
|
|
|
|
pWatch - Supplies a pointer to a watchdog object.
|
|
|
|
bIncremental - If TRUE the watchdog will resume only when
|
|
SuspendCount reaches 0, if FALSE watchdog resumes
|
|
immediately and SuspendCount is forced to 0.
|
|
|
|
Return Value:
|
|
|
|
None.
|
|
|
|
--*/
|
|
|
|
{
|
|
KIRQL oldIrql;
|
|
BOOLEAN bResumed = FALSE;
|
|
|
|
ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
|
|
ASSERT(NULL != pWatch);
|
|
|
|
//
|
|
// Raise IRQL to dispatcher level and lock dispatcher database.
|
|
//
|
|
|
|
KeAcquireSpinLock(&(pWatch->Header.SpinLock), &oldIrql);
|
|
|
|
if (TRUE == bIncremental)
|
|
{
|
|
if (pWatch->SuspendCount)
|
|
{
|
|
pWatch->SuspendCount--;
|
|
|
|
if (0 == pWatch->SuspendCount)
|
|
{
|
|
bResumed = TRUE;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (pWatch->SuspendCount)
|
|
{
|
|
pWatch->SuspendCount = 0;
|
|
bResumed = TRUE;
|
|
}
|
|
}
|
|
|
|
//
|
|
// If we had a timer running, and we are resuming for the first time,
|
|
// and still have some due time left, we'll have to restart timer.
|
|
//
|
|
|
|
if (pWatch->StartCount && (TRUE == bResumed) && (0 != pWatch->DueTime.QuadPart))
|
|
{
|
|
LARGE_INTEGER liDueTime;
|
|
|
|
//
|
|
// Refresh currect time.
|
|
//
|
|
|
|
pWatch->LastKernelTime = KeQueryRuntimeThread(pWatch->Thread, &(pWatch->LastUserTime));
|
|
|
|
//
|
|
// Make sure ULONG counters won't overflow.
|
|
//
|
|
|
|
liDueTime.QuadPart = pWatch->DueTime.QuadPart;
|
|
|
|
if (liDueTime.QuadPart < -WD_MAX_WAIT)
|
|
{
|
|
liDueTime.QuadPart = -WD_MAX_WAIT;
|
|
}
|
|
|
|
KeSetTimerEx(&(pWatch->Timer), liDueTime, 0, &(pWatch->TimerDpc));
|
|
}
|
|
|
|
//
|
|
// Unlock the dispatcher database and lower IRQL to its previous value.
|
|
//
|
|
|
|
KeReleaseSpinLock(&(pWatch->Header.SpinLock), oldIrql);
|
|
|
|
return;
|
|
} // WdSuspendWatch()
|
|
|
|
WATCHDOGAPI
|
|
VOID
|
|
WdResetWatch(
|
|
IN PWATCHDOG pWatch
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This function resets a started watchdog, i.e. it restarts timeout
|
|
measurement from the scratch.
|
|
Note: If the watchdog is suspened it will remain suspended.
|
|
|
|
Arguments:
|
|
|
|
pWatch - Supplies a pointer to a watchdog object.
|
|
|
|
Return Value:
|
|
|
|
None.
|
|
|
|
--*/
|
|
|
|
{
|
|
KIRQL oldIrql;
|
|
|
|
ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
|
|
ASSERT(NULL != pWatch);
|
|
|
|
//
|
|
// Raise IRQL to dispatcher level and lock dispatcher database.
|
|
//
|
|
|
|
KeAcquireSpinLock(&(pWatch->Header.SpinLock), &oldIrql);
|
|
|
|
if (pWatch->StartCount)
|
|
{
|
|
LARGE_INTEGER liDueTime;
|
|
|
|
pWatch->DueTime.QuadPart = pWatch->InitialDueTime.QuadPart;
|
|
pWatch->LastKernelTime = KeQueryRuntimeThread(pWatch->Thread, &(pWatch->LastUserTime));
|
|
|
|
//
|
|
// Make sure ULONG counters won't overflow.
|
|
//
|
|
|
|
liDueTime.QuadPart = pWatch->DueTime.QuadPart;
|
|
|
|
if (liDueTime.QuadPart < -WD_MAX_WAIT)
|
|
{
|
|
liDueTime.QuadPart = -WD_MAX_WAIT;
|
|
}
|
|
|
|
if (0 == pWatch->SuspendCount)
|
|
{
|
|
KeSetTimerEx(&(pWatch->Timer), liDueTime, 0, &(pWatch->TimerDpc));
|
|
}
|
|
}
|
|
|
|
//
|
|
// Unlock the dispatcher database and lower IRQL to its previous value.
|
|
//
|
|
|
|
KeReleaseSpinLock(&(pWatch->Header.SpinLock), oldIrql);
|
|
|
|
return;
|
|
} // WdResetWatch()
|
|
|
|
VOID
|
|
WdWatchdogDpcCallback(
|
|
IN PKDPC pDpc,
|
|
IN PVOID pContext,
|
|
IN PVOID pSystemArgument1,
|
|
IN PVOID pSystemArgument2
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This function is a DPC callback routine for timer object embedded in the
|
|
watchdog object. It checks thread time and if the wait condition is
|
|
satisfied it queues original (client) DPC. In case if the wait condition
|
|
is not yet satisfied it call KeSetTimerEx().
|
|
|
|
Arguments:
|
|
|
|
pDpc - Supplies a pointer to a DPC object.
|
|
|
|
pContext - Supplies a pointer to a watchdog object.
|
|
|
|
pSystemArgument1/2 - Supply time when embedded KTIMER expired.
|
|
|
|
Return Value:
|
|
|
|
None.
|
|
|
|
--*/
|
|
|
|
{
|
|
PWATCHDOG pWatch;
|
|
ULARGE_INTEGER uliThreadTime;
|
|
LARGE_INTEGER liDelta;
|
|
ULONG ulKernelTime;
|
|
ULONG ulUserTime;
|
|
|
|
ASSERT(KeGetCurrentIrql() == DISPATCH_LEVEL);
|
|
ASSERT(NULL != pContext);
|
|
|
|
pWatch = (PWATCHDOG)pContext;
|
|
|
|
KeAcquireSpinLockAtDpcLevel(&(pWatch->Header.SpinLock));
|
|
|
|
ASSERT(0 == pWatch->SuspendCount);
|
|
|
|
//
|
|
// Get thread's current time stamps.
|
|
//
|
|
|
|
ulKernelTime = KeQueryRuntimeThread(pWatch->Thread, &ulUserTime);
|
|
|
|
switch (pWatch->Header.TimeType)
|
|
{
|
|
case WdKernelTime:
|
|
|
|
uliThreadTime.QuadPart = ulKernelTime;
|
|
|
|
//
|
|
// Handle counter rollovers.
|
|
//
|
|
|
|
if (ulKernelTime < pWatch->LastKernelTime)
|
|
{
|
|
uliThreadTime.QuadPart += (ULONG)(-1) - pWatch->LastKernelTime + 1;
|
|
}
|
|
|
|
liDelta.QuadPart = uliThreadTime.QuadPart - pWatch->LastKernelTime;
|
|
|
|
break;
|
|
|
|
case WdUserTime:
|
|
|
|
uliThreadTime.QuadPart = ulUserTime;
|
|
|
|
//
|
|
// Handle counter rollovers.
|
|
//
|
|
|
|
if (ulUserTime < pWatch->LastUserTime)
|
|
{
|
|
uliThreadTime.QuadPart += (ULONG)(-1) - pWatch->LastUserTime + 1;
|
|
}
|
|
|
|
liDelta.QuadPart = uliThreadTime.QuadPart - pWatch->LastUserTime;
|
|
|
|
break;
|
|
|
|
case WdFullTime:
|
|
|
|
uliThreadTime.QuadPart = ulKernelTime + ulUserTime;
|
|
|
|
//
|
|
// Handle counter rollovers.
|
|
//
|
|
|
|
if (ulKernelTime < pWatch->LastKernelTime)
|
|
{
|
|
uliThreadTime.QuadPart += (ULONG)(-1) - pWatch->LastKernelTime + 1;
|
|
}
|
|
|
|
if (ulUserTime < pWatch->LastUserTime)
|
|
{
|
|
uliThreadTime.QuadPart += (ULONG)(-1) - pWatch->LastUserTime + 1;
|
|
}
|
|
|
|
liDelta.QuadPart = uliThreadTime.QuadPart - (pWatch->LastKernelTime +
|
|
pWatch->LastUserTime);
|
|
|
|
break;
|
|
|
|
default:
|
|
|
|
ASSERT(FALSE);
|
|
liDelta.QuadPart = 0;
|
|
break;
|
|
}
|
|
|
|
liDelta.QuadPart *= pWatch->TimeIncrement;
|
|
|
|
//
|
|
// Update time values stored in timer per thread object to current values.
|
|
//
|
|
|
|
pWatch->LastKernelTime = ulKernelTime;
|
|
pWatch->LastUserTime = ulUserTime;
|
|
pWatch->DueTime.QuadPart += liDelta.QuadPart;
|
|
|
|
if (pWatch->DueTime.QuadPart >= 0)
|
|
{
|
|
//
|
|
// We're done waiting - update event type and queue client DPC if defined.
|
|
//
|
|
|
|
pWatch->Header.LastEvent = WdTimeoutEvent;
|
|
|
|
if (NULL != pWatch->ClientDpc)
|
|
{
|
|
//
|
|
// Bump up references to objects we're going to touch in client DPC.
|
|
//
|
|
|
|
ObReferenceObject(pWatch->Thread);
|
|
WdReferenceObject(pWatch);
|
|
|
|
if (KeInsertQueueDpc(pWatch->ClientDpc, pWatch->Thread, pWatch) == FALSE)
|
|
{
|
|
//
|
|
// Already in queue, drop references.
|
|
//
|
|
|
|
ObDereferenceObject(pWatch->Thread);
|
|
WdDereferenceObject(pWatch);
|
|
}
|
|
else
|
|
{
|
|
//
|
|
// Keep track of qeueued thread in case we cancel this DPC.
|
|
//
|
|
|
|
pWatch->Header.LastQueuedThread = pWatch->Thread;
|
|
}
|
|
}
|
|
|
|
//
|
|
// Make sure due time is zero (in case of suspend / resume).
|
|
//
|
|
|
|
pWatch->DueTime.QuadPart = 0;
|
|
}
|
|
else
|
|
{
|
|
//
|
|
// Not there yet - wait some more.
|
|
//
|
|
|
|
liDelta.QuadPart = pWatch->DueTime.QuadPart;
|
|
|
|
//
|
|
// Make sure ULONG counters won't overflow.
|
|
//
|
|
|
|
if (liDelta.QuadPart < -WD_MAX_WAIT)
|
|
{
|
|
liDelta.QuadPart = -WD_MAX_WAIT;
|
|
}
|
|
|
|
KeSetTimerEx(&(pWatch->Timer), liDelta, 0, &(pWatch->TimerDpc));
|
|
}
|
|
|
|
KeReleaseSpinLockFromDpcLevel(&(pWatch->Header.SpinLock));
|
|
|
|
return;
|
|
} // WdWatchdogDpcCallback()
|