https://git.reactos.org/?p=reactos.git;a=commitdiff;h=ae1d272add25af42bd1acd453d41407363f6658a
commit ae1d272add25af42bd1acd453d41407363f6658a Author: Thomas Faber <[email protected]> AuthorDate: Mon Aug 17 04:05:53 2020 +0200 Commit: Thomas Faber <[email protected]> CommitDate: Fri Nov 27 10:31:41 2020 +0100 [NTOS:PNP] Avoid recursion in IopTraverseDeviceTree(Node). CORE-17215 --- ntoskrnl/io/pnpmgr/devnode.c | 87 +++++++++++++++++++++++--------------------- 1 file changed, 46 insertions(+), 41 deletions(-) diff --git a/ntoskrnl/io/pnpmgr/devnode.c b/ntoskrnl/io/pnpmgr/devnode.c index 6f5e029ceff..a068cd71ddb 100644 --- a/ntoskrnl/io/pnpmgr/devnode.c +++ b/ntoskrnl/io/pnpmgr/devnode.c @@ -321,56 +321,36 @@ IopFreeDeviceNode( static NTSTATUS -IopTraverseDeviceTreeNode( +IopFindNextDeviceNodeForTraversal( _In_ PDEVICETREE_TRAVERSE_CONTEXT Context) { - PDEVICE_NODE ParentDeviceNode; - PDEVICE_NODE ChildDeviceNode; - PDEVICE_NODE NextDeviceNode; - NTSTATUS Status; - - /* Copy context data so we don't overwrite it in subsequent calls to this function */ - ParentDeviceNode = Context->DeviceNode; - - /* HACK: Keep a reference to the PDO so we can keep traversing the tree - * if the device is deleted. In a perfect world, children would have to be - * deleted before their parents, and we'd restart the traversal after - * deleting a device node. */ - ObReferenceObject(ParentDeviceNode->PhysicalDeviceObject); - - /* Call the action routine */ - Status = (Context->Action)(ParentDeviceNode, Context->Context); - if (!NT_SUCCESS(Status)) + /* If we have a child, simply go down the tree */ + if (Context->DeviceNode->Child != NULL) { - ObDereferenceObject(ParentDeviceNode->PhysicalDeviceObject); - return Status; + ASSERT(Context->DeviceNode->Child->Parent == Context->DeviceNode); + Context->DeviceNode = Context->DeviceNode->Child; + return STATUS_SUCCESS; } - /* Traversal of all children nodes */ - for (ChildDeviceNode = ParentDeviceNode->Child; - ChildDeviceNode != NULL; - ChildDeviceNode = NextDeviceNode) + while (Context->DeviceNode != Context->FirstDeviceNode) { - /* HACK: We need this reference to ensure we can get Sibling below. */ - ObReferenceObject(ChildDeviceNode->PhysicalDeviceObject); - - /* Pass the current device node to the action routine */ - Context->DeviceNode = ChildDeviceNode; - - Status = IopTraverseDeviceTreeNode(Context); - if (!NT_SUCCESS(Status)) + /* All children processed -- go sideways */ + if (Context->DeviceNode->Sibling != NULL) { - ObDereferenceObject(ChildDeviceNode->PhysicalDeviceObject); - ObDereferenceObject(ParentDeviceNode->PhysicalDeviceObject); - return Status; + ASSERT(Context->DeviceNode->Sibling->Parent == Context->DeviceNode->Parent); + Context->DeviceNode = Context->DeviceNode->Sibling; + return STATUS_SUCCESS; } - NextDeviceNode = ChildDeviceNode->Sibling; - ObDereferenceObject(ChildDeviceNode->PhysicalDeviceObject); + /* We're the last sibling -- go back up */ + ASSERT(Context->DeviceNode->Parent->LastChild == Context->DeviceNode); + Context->DeviceNode = Context->DeviceNode->Parent; + + /* We already visited the parent and all its children, so keep looking */ } - ObDereferenceObject(ParentDeviceNode->PhysicalDeviceObject); - return Status; + /* Done with all children of the start node -- stop enumeration */ + return STATUS_UNSUCCESSFUL; } NTSTATUS @@ -378,6 +358,7 @@ IopTraverseDeviceTree( _In_ PDEVICETREE_TRAVERSE_CONTEXT Context) { NTSTATUS Status; + PDEVICE_NODE DeviceNode; DPRINT("Context 0x%p\n", Context); @@ -387,8 +368,32 @@ IopTraverseDeviceTree( /* Start from the specified device node */ Context->DeviceNode = Context->FirstDeviceNode; - /* Recursively traverse the device tree */ - Status = IopTraverseDeviceTreeNode(Context); + /* Traverse the device tree */ + do + { + DeviceNode = Context->DeviceNode; + + /* HACK: Keep a reference to the PDO so we can keep traversing the tree + * if the device is deleted. In a perfect world, children would have to be + * deleted before their parents, and we'd restart the traversal after + * deleting a device node. */ + ObReferenceObject(DeviceNode->PhysicalDeviceObject); + + /* Call the action routine */ + Status = (Context->Action)(DeviceNode, Context->Context); + if (NT_SUCCESS(Status)) + { + /* Find next device node */ + ASSERT(Context->DeviceNode == DeviceNode); + Status = IopFindNextDeviceNodeForTraversal(Context); + } + + /* We need to either abort or make progress */ + ASSERT(!NT_SUCCESS(Status) || Context->DeviceNode != DeviceNode); + + ObDereferenceObject(DeviceNode->PhysicalDeviceObject); + } while (NT_SUCCESS(Status)); + if (Status == STATUS_UNSUCCESSFUL) { /* The action routine just wanted to terminate the traversal with status
