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[NTOS:PNP] Avoid recursion when walking the device tree.

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Thomas Faber 2023-01-14 17:40:14 -05:00
parent 3dd3d10531
commit c0e7eaf403
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GPG key ID: 076E7C3D44720826
1 changed files with 33 additions and 24 deletions
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57
ntoskrnl/io/pnpmgr/plugplay.c
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@ -18,6 +18,12 @@ typedef struct _PNP_EVENT_ENTRY
PLUGPLAY_EVENT_BLOCK Event; PLUGPLAY_EVENT_BLOCK Event;
} PNP_EVENT_ENTRY, *PPNP_EVENT_ENTRY; } PNP_EVENT_ENTRY, *PPNP_EVENT_ENTRY;
typedef struct _IOP_FIND_DEVICE_INSTANCE_TRAVERSE_CONTEXT
{
PCUNICODE_STRING InstancePath;
PDEVICE_OBJECT DeviceObject;
} IOP_FIND_DEVICE_INSTANCE_TRAVERSE_CONTEXT, *PIOP_FIND_DEVICE_INSTANCE_TRAVERSE_CONTEXT;
/* GLOBALS *******************************************************************/ /* GLOBALS *******************************************************************/
@ -88,39 +94,32 @@ IopQueueTargetDeviceEvent(const GUID *Guid,
return STATUS_SUCCESS; return STATUS_SUCCESS;
} }
NTSTATUS
static PDEVICE_OBJECT IopFindDeviceInstanceTraverse(
IopTraverseDeviceNode(PDEVICE_NODE Node, PUNICODE_STRING DeviceInstance) _In_ PDEVICE_NODE DeviceNode,
_Inout_ PVOID Context)
{ {
PDEVICE_OBJECT DeviceObject; PIOP_FIND_DEVICE_INSTANCE_TRAVERSE_CONTEXT DeviceInstanceContext = Context;
PDEVICE_NODE ChildNode;
if (RtlEqualUnicodeString(&Node->InstancePath, if (RtlEqualUnicodeString(&DeviceNode->InstancePath,
DeviceInstance, TRUE)) DeviceInstanceContext->InstancePath, TRUE))
{ {
ObReferenceObject(Node->PhysicalDeviceObject); ObReferenceObject(DeviceNode->PhysicalDeviceObject);
return Node->PhysicalDeviceObject; DeviceInstanceContext->DeviceObject = DeviceNode->PhysicalDeviceObject;
/* Stop enumeration */
return STATUS_UNSUCCESSFUL;
} }
/* Traversal of all children nodes */ return STATUS_SUCCESS;
for (ChildNode = Node->Child;
ChildNode != NULL;
ChildNode = ChildNode->Sibling)
{
DeviceObject = IopTraverseDeviceNode(ChildNode, DeviceInstance);
if (DeviceObject != NULL)
{
return DeviceObject;
}
}
return NULL;
} }
PDEVICE_OBJECT PDEVICE_OBJECT
IopGetDeviceObjectFromDeviceInstance(PUNICODE_STRING DeviceInstance) IopGetDeviceObjectFromDeviceInstance(PUNICODE_STRING DeviceInstance)
{ {
DEVICETREE_TRAVERSE_CONTEXT Context;
IOP_FIND_DEVICE_INSTANCE_TRAVERSE_CONTEXT DeviceInstanceContext;
if (IopRootDeviceNode == NULL) if (IopRootDeviceNode == NULL)
return NULL; return NULL;
@ -136,7 +135,17 @@ IopGetDeviceObjectFromDeviceInstance(PUNICODE_STRING DeviceInstance)
return NULL; return NULL;
} }
return IopTraverseDeviceNode(IopRootDeviceNode, DeviceInstance); /* Traverse the device tree to find the matching device node */
DeviceInstanceContext.InstancePath = DeviceInstance;
DeviceInstanceContext.DeviceObject = NULL;
IopInitDeviceTreeTraverseContext(&Context,
IopRootDeviceNode,
IopFindDeviceInstanceTraverse,
&DeviceInstanceContext);
(void)IopTraverseDeviceTree(&Context);
/* In case of error or instance not found, this will still be NULL from above. */
return DeviceInstanceContext.DeviceObject;
} }
static NTSTATUS static NTSTATUS