IoAttachDevice源码
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IoAttachDevice源码
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IoAttachDevice調(diào)用了IoAttachDeviceToDeviceStackSafe,
IoAttachDevice調(diào)用了IoAttachDeviceToDeviceStack
IoAttachDeviceToDeviceStack調(diào)用了IopAttachDeviceToDeviceStackSafe
IoAttachDeviceToDeviceStackSafe調(diào)用了IopAttachDeviceToDeviceStackSafe
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IopAttachDeviceToDeviceStackSafe的代碼為:
PDEVICE_OBJECT IopAttachDeviceToDeviceStackSafe(IN PDEVICE_OBJECT SourceDevice,IN PDEVICE_OBJECT TargetDevice,OUT PDEVICE_OBJECT *AttachedToDeviceObject OPTIONAL)/*++Routine Description:This routine attaches the source device object to the target deviceobject and returns a pointer to the actual device attached to, ifsuccessful.Arguments:SourceDevice - Specifies the device object that is to be attached tothe target device.TargetDevice - Specifies the device object to which the attachment isto occur.AttachedToDeviceObject - Specifies a pointer where the attached to device objectis stored. Its updated while holding the database lock so that when a filter gets an IRPits attached to device object field is updated correctly.Return Value:If successful, this function returns a pointer to the device object towhich the attachment actually occurred.If unsuccessful, this function returns NULL. (This could happen if thedevice currently at the top of the attachment chain is being unloaded,deleted or initialized.)--*/{PDEVICE_OBJECT deviceObject;PDEVOBJ_EXTENSION sourceExtension;KIRQL irql;//// Retrieve a pointer to the source device object's extension outside// of the IopDatabaseLock, since it isn't protected by that.// sourceExtension = SourceDevice->DeviceObjectExtension;//// Get a pointer to the topmost device object in the stack of devices,// beginning with the TargetDevice, and attach to it.// irql = KeAcquireQueuedSpinLock( LockQueueIoDatabaseLock );//// Tell the Special IRP code the stack has changed. Code that will reexamine// the stack takes the database lock, so we can place the call here. This// also allows us to assert correct behavior *before* the stack is built up.// IOV_ATTACH_DEVICE_TO_DEVICE_STACK(SourceDevice, TargetDevice);deviceObject = IoGetAttachedDevice( TargetDevice );//// Make sure that the SourceDevice object isn't already attached to// something else, this is now illegal.// ASSERT( sourceExtension->AttachedTo == NULL );//// Now attach to the device, provided that it is not being unloaded,// deleted or initializing.// if (deviceObject->Flags & DO_DEVICE_INITIALIZING ||deviceObject->DeviceObjectExtension->ExtensionFlags &(DOE_UNLOAD_PENDING | DOE_DELETE_PENDING | DOE_REMOVE_PENDING | DOE_REMOVE_PROCESSED)) {//// The device currently at the top of the attachment chain is being// unloaded, deleted or initialized.// deviceObject = (PDEVICE_OBJECT) NULL;} else {//// Perform the attachment. First update the device previously at the// top of the attachment chain.// deviceObject->AttachedDevice = SourceDevice;deviceObject->Spare1++;//// Now update the new top-of-attachment-chain.// SourceDevice->StackSize = (UCHAR) (deviceObject->StackSize + 1);SourceDevice->AlignmentRequirement = deviceObject->AlignmentRequirement;SourceDevice->SectorSize = deviceObject->SectorSize;if (deviceObject->DeviceObjectExtension->ExtensionFlags & DOE_START_PENDING) {SourceDevice->DeviceObjectExtension->ExtensionFlags |= DOE_START_PENDING;}//// Attachment chain is doubly-linked.// sourceExtension->AttachedTo = deviceObject;}//// Atomically update this field inside the lock.// The caller has to ensure that this location is in non-paged pool.// This is required so that a filesystem filter can attach to a device and before it// gets an IRP it can update its lower device object pointer.// if (AttachedToDeviceObject) {*AttachedToDeviceObject = deviceObject;}KeReleaseQueuedSpinLock( LockQueueIoDatabaseLock, irql );return deviceObject; }轉(zhuǎn)載于:https://www.cnblogs.com/stonehat/archive/2012/07/20/2601799.html
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