698 lines
20 KiB
C
698 lines
20 KiB
C
/*++
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Copyright (c) 2001 Microsoft Corporation
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Module Name:
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keyedevent.c
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Abstract:
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This module houses routines that do keyed event processing.
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Author:
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Neill Clift (NeillC) 25-Apr-2001
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Revision History:
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--*/
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#include "exp.h"
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#pragma hdrstop
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#ifdef ALLOC_PRAGMA
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#pragma alloc_text(INIT, ExpKeyedEventInitialization)
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#pragma alloc_text(PAGE, NtCreateKeyedEvent)
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#pragma alloc_text(PAGE, NtOpenKeyedEvent)
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#pragma alloc_text(PAGE, NtReleaseKeyedEvent)
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#pragma alloc_text(PAGE, NtWaitForKeyedEvent)
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#endif
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//
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// Define the keyed event object type
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//
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typedef struct _KEYED_EVENT_OBJECT {
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EX_PUSH_LOCK Lock;
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LIST_ENTRY WaitQueue;
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} KEYED_EVENT_OBJECT, *PKEYED_EVENT_OBJECT;
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POBJECT_TYPE ExpKeyedEventObjectType;
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//
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// The low bit of the keyvalue signifies that we are a release thread waiting
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// for the wait thread to enter the keyed event code.
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//
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#define KEYVALUE_RELEASE 1
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#define LOCK_KEYED_EVENT_EXCLUSIVE(xxxKeyedEventObject,xxxCurrentThread) { \
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KeEnterCriticalRegionThread (&(xxxCurrentThread)->Tcb); \
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ExAcquirePushLockExclusive (&(xxxKeyedEventObject)->Lock); \
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}
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#define UNLOCK_KEYED_EVENT_EXCLUSIVE(xxxKeyedEventObject,xxxCurrentThread) { \
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ExReleasePushLockExclusive (&(xxxKeyedEventObject)->Lock); \
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KeLeaveCriticalRegionThread (&(xxxCurrentThread)->Tcb); \
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}
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#define UNLOCK_KEYED_EVENT_EXCLUSIVE_UNSAFE(xxxKeyedEventObject) { \
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ExReleasePushLockExclusive (&(xxxKeyedEventObject)->Lock); \
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}
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NTSTATUS
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ExpKeyedEventInitialization (
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VOID
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)
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/*++
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Routine Description:
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Initialize the keyed event objects and globals.
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Arguments:
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None.
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Return Value:
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NTSTATUS - Status of call
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--*/
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{
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NTSTATUS Status;
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UNICODE_STRING Name;
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OBJECT_TYPE_INITIALIZER oti = {0};
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OBJECT_ATTRIBUTES oa;
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SECURITY_DESCRIPTOR SecurityDescriptor;
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PACL Dacl;
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ULONG DaclLength;
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HANDLE KeyedEventHandle;
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GENERIC_MAPPING GenericMapping = {STANDARD_RIGHTS_READ | KEYEDEVENT_WAIT,
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STANDARD_RIGHTS_WRITE | KEYEDEVENT_WAKE,
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STANDARD_RIGHTS_EXECUTE,
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KEYEDEVENT_ALL_ACCESS};
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PAGED_CODE ();
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RtlInitUnicodeString (&Name, L"KeyedEvent");
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oti.Length = sizeof (oti);
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oti.InvalidAttributes = 0;
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oti.PoolType = PagedPool;
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oti.ValidAccessMask = KEYEDEVENT_ALL_ACCESS;
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oti.GenericMapping = GenericMapping;
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oti.DefaultPagedPoolCharge = 0;
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oti.DefaultNonPagedPoolCharge = 0;
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oti.UseDefaultObject = TRUE;
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Status = ObCreateObjectType (&Name, &oti, NULL, &ExpKeyedEventObjectType);
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if (!NT_SUCCESS (Status)) {
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return Status;
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}
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//
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// Create a global object for processes that are out of memory
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//
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Status = RtlCreateSecurityDescriptor (&SecurityDescriptor,
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SECURITY_DESCRIPTOR_REVISION);
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if (!NT_SUCCESS (Status)) {
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return Status;
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}
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DaclLength = sizeof (ACL) + sizeof (ACCESS_ALLOWED_ACE) * 3 +
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RtlLengthSid (SeLocalSystemSid) +
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RtlLengthSid (SeAliasAdminsSid) +
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RtlLengthSid (SeWorldSid);
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Dacl = ExAllocatePoolWithTag (PagedPool, DaclLength, 'lcaD');
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if (Dacl == NULL) {
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return STATUS_INSUFFICIENT_RESOURCES;
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}
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Status = RtlCreateAcl (Dacl, DaclLength, ACL_REVISION);
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if (!NT_SUCCESS (Status)) {
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ExFreePool (Dacl);
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return Status;
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}
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Status = RtlAddAccessAllowedAce (Dacl,
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ACL_REVISION,
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KEYEDEVENT_ALL_ACCESS,
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SeAliasAdminsSid);
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if (!NT_SUCCESS (Status)) {
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ExFreePool (Dacl);
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return Status;
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}
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Status = RtlAddAccessAllowedAce (Dacl,
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ACL_REVISION,
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KEYEDEVENT_ALL_ACCESS,
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SeLocalSystemSid);
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if (!NT_SUCCESS (Status)) {
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ExFreePool (Dacl);
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return Status;
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}
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Status = RtlAddAccessAllowedAce (Dacl,
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ACL_REVISION,
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KEYEDEVENT_WAIT|KEYEDEVENT_WAKE|READ_CONTROL,
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SeWorldSid);
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if (!NT_SUCCESS (Status)) {
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ExFreePool (Dacl);
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return Status;
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}
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Status = RtlSetDaclSecurityDescriptor (&SecurityDescriptor,
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TRUE,
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Dacl,
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FALSE);
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if (!NT_SUCCESS (Status)) {
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ExFreePool (Dacl);
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return Status;
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}
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RtlInitUnicodeString (&Name, L"\\KernelObjects\\CritSecOutOfMemoryEvent");
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InitializeObjectAttributes (&oa, &Name, OBJ_PERMANENT, NULL, &SecurityDescriptor);
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Status = ZwCreateKeyedEvent (&KeyedEventHandle,
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KEYEDEVENT_ALL_ACCESS,
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&oa,
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0);
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ExFreePool (Dacl);
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if (NT_SUCCESS (Status)) {
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Status = ZwClose (KeyedEventHandle);
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}
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return Status;
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}
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NTSTATUS
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NtCreateKeyedEvent (
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OUT PHANDLE KeyedEventHandle,
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IN ACCESS_MASK DesiredAccess,
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IN POBJECT_ATTRIBUTES ObjectAttributes OPTIONAL,
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IN ULONG Flags
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)
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/*++
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Routine Description:
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Create a keyed event object and return its handle
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Arguments:
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KeyedEventHandle - Address to store returned handle in
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DesiredAccess - Access required to keyed event
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ObjectAttributes - Object attributes block to describe parent
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handle and name of event
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Return Value:
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NTSTATUS - Status of call
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--*/
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{
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NTSTATUS Status;
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PKEYED_EVENT_OBJECT KeyedEventObject;
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HANDLE Handle;
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KPROCESSOR_MODE PreviousMode;
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//
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// Get previous processor mode and probe output arguments if necessary.
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// Zero the handle for error paths.
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//
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PreviousMode = KeGetPreviousMode();
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try {
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if (PreviousMode != KernelMode) {
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ProbeForReadSmallStructure (KeyedEventHandle,
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sizeof (*KeyedEventHandle),
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sizeof (*KeyedEventHandle));
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}
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*KeyedEventHandle = NULL;
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} except (ExSystemExceptionFilter ()) {
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return GetExceptionCode ();
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}
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if (Flags != 0) {
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return STATUS_INVALID_PARAMETER_4;
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}
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//
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// Create a new keyed event object and initialize it.
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//
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Status = ObCreateObject (PreviousMode,
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ExpKeyedEventObjectType,
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ObjectAttributes,
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PreviousMode,
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NULL,
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sizeof (KEYED_EVENT_OBJECT),
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0,
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0,
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&KeyedEventObject);
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if (!NT_SUCCESS (Status)) {
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return Status;
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}
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//
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// Initialize the lock and wait queue
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//
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ExInitializePushLock (&KeyedEventObject->Lock);
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InitializeListHead (&KeyedEventObject->WaitQueue);
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//
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// Insert the object into the handle table
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//
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Status = ObInsertObject (KeyedEventObject,
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NULL,
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DesiredAccess,
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0,
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NULL,
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&Handle);
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if (!NT_SUCCESS (Status)) {
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return Status;
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}
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try {
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*KeyedEventHandle = Handle;
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} except (ExSystemExceptionFilter ()) {
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//
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// The caller changed the page protection or deleted the momory for the handle.
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// No point closing the handle as process rundown will do that and we don't
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// know its still the same handle
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//
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Status = GetExceptionCode ();
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}
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return Status;
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}
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NTSTATUS
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NtOpenKeyedEvent (
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OUT PHANDLE KeyedEventHandle,
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IN ACCESS_MASK DesiredAccess,
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IN POBJECT_ATTRIBUTES ObjectAttributes
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)
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/*++
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Routine Description:
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Open a keyed event object and return its handle
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Arguments:
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KeyedEventHandle - Address to store returned handle in
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DesiredAccess - Access required to keyed event
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ObjectAttributes - Object attributes block to describe parent
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handle and name of event
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Return Value:
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NTSTATUS - Status of call
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--*/
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{
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HANDLE Handle;
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KPROCESSOR_MODE PreviousMode;
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NTSTATUS Status;
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//
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// Get previous processor mode and probe output handle address
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// if necessary.
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//
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PreviousMode = KeGetPreviousMode();
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try {
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if (PreviousMode != KernelMode) {
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ProbeForReadSmallStructure (KeyedEventHandle,
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sizeof (*KeyedEventHandle),
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sizeof (*KeyedEventHandle));
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}
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*KeyedEventHandle = NULL;
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} except (ExSystemExceptionFilter ()) {
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return GetExceptionCode ();
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}
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//
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// Open handle to the keyed event object with the specified desired access.
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//
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Status = ObOpenObjectByName (ObjectAttributes,
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ExpKeyedEventObjectType,
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PreviousMode,
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NULL,
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DesiredAccess,
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NULL,
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&Handle);
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if (NT_SUCCESS (Status)) {
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try {
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*KeyedEventHandle = Handle;
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} except (ExSystemExceptionFilter ()) {
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Status = GetExceptionCode ();
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}
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}
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return Status;
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}
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NTSTATUS
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NtReleaseKeyedEvent (
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IN HANDLE KeyedEventHandle,
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IN PVOID KeyValue,
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IN BOOLEAN Alertable,
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IN PLARGE_INTEGER Timeout OPTIONAL
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)
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/*++
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Routine Description:
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Release a previous or soon to be waiter with a matching key
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Arguments:
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KeyedEventHandle - Handle to a keyed event
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KeyValue - Value to be used to match the waiter against
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Alertable - Should the wait be alertable, we rarely should have to wait
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Timeout - Timout value for the wait, waits should be rare
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Return Value:
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NTSTATUS - Status of call
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--*/
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{
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NTSTATUS Status;
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KPROCESSOR_MODE PreviousMode;
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PKEYED_EVENT_OBJECT KeyedEventObject;
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PETHREAD CurrentThread, TargetThread;
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PEPROCESS CurrentProcess;
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PLIST_ENTRY ListHead, ListEntry;
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LARGE_INTEGER TimeoutValue;
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PVOID OldKeyValue = NULL;
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if ((((ULONG_PTR)KeyValue) & KEYVALUE_RELEASE) != 0) {
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return STATUS_INVALID_PARAMETER_1;
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}
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CurrentThread = PsGetCurrentThread ();
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PreviousMode = KeGetPreviousModeByThread (&CurrentThread->Tcb);
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if (Timeout != NULL) {
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try {
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if (PreviousMode != KernelMode) {
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ProbeForRead (Timeout, sizeof (*Timeout), sizeof (UCHAR));
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}
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TimeoutValue = *Timeout;
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Timeout = &TimeoutValue;
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} except(ExSystemExceptionFilter ()) {
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return GetExceptionCode ();
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}
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}
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Status = ObReferenceObjectByHandle (KeyedEventHandle,
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KEYEDEVENT_WAKE,
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ExpKeyedEventObjectType,
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PreviousMode,
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&KeyedEventObject,
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NULL);
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if (!NT_SUCCESS (Status)) {
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return Status;
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}
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CurrentProcess = PsGetCurrentProcessByThread (CurrentThread);
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ListHead = &KeyedEventObject->WaitQueue;
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LOCK_KEYED_EVENT_EXCLUSIVE (KeyedEventObject, CurrentThread);
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ListEntry = ListHead->Flink;
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while (1) {
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if (ListEntry == ListHead) {
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//
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// We could not find a key matching ours in the list.
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// Either somebody called us with wrong values or the waiter
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// has not managed to get queued yet. We wait ourselves
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// to be released by the waiter.
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//
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OldKeyValue = CurrentThread->KeyedWaitValue;
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CurrentThread->KeyedWaitValue = (PVOID) (((ULONG_PTR)KeyValue)|KEYVALUE_RELEASE);
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//
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// Insert the thread at the head of the list. We establish an invariant
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// were release waiters are always at the front of the queue to improve
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// the wait code since it only has to search as far as the first non-release
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// waiter.
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//
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InsertHeadList (ListHead, &CurrentThread->KeyedWaitChain);
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TargetThread = NULL;
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break;
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} else {
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TargetThread = CONTAINING_RECORD (ListEntry, ETHREAD, KeyedWaitChain);
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if (TargetThread->KeyedWaitValue == KeyValue &&
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THREAD_TO_PROCESS (TargetThread) == CurrentProcess) {
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RemoveEntryList (ListEntry);
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InitializeListHead (ListEntry);
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break;
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}
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}
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ListEntry = ListEntry->Flink;
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}
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//
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// Release the lock but leave APC's disabled.
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// This prevents us from being suspended and holding up the target.
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//
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UNLOCK_KEYED_EVENT_EXCLUSIVE_UNSAFE (KeyedEventObject);
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if (TargetThread != NULL) {
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KeReleaseSemaphore (&TargetThread->KeyedWaitSemaphore,
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SEMAPHORE_INCREMENT,
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1,
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FALSE);
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KeLeaveCriticalRegionThread (&CurrentThread->Tcb);
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} else {
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KeLeaveCriticalRegionThread (&CurrentThread->Tcb);
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Status = KeWaitForSingleObject (&CurrentThread->KeyedWaitSemaphore,
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Executive,
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PreviousMode,
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Alertable,
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Timeout);
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//
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// If we were woken by termination then we must manualy remove
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// ourselves from the queue
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//
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if (Status != STATUS_SUCCESS) {
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BOOLEAN Wait = TRUE;
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LOCK_KEYED_EVENT_EXCLUSIVE (KeyedEventObject, CurrentThread);
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if (!IsListEmpty (&CurrentThread->KeyedWaitChain)) {
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RemoveEntryList (&CurrentThread->KeyedWaitChain);
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InitializeListHead (&CurrentThread->KeyedWaitChain);
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Wait = FALSE;
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}
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UNLOCK_KEYED_EVENT_EXCLUSIVE (KeyedEventObject, CurrentThread);
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//
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// If this thread was no longer in the queue then another thread
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// must be about to wake us up. Wait for that wake.
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//
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if (Wait) {
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KeWaitForSingleObject (&CurrentThread->KeyedWaitSemaphore,
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Executive,
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KernelMode,
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FALSE,
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NULL);
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}
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}
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CurrentThread->KeyedWaitValue = OldKeyValue;
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}
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ObDereferenceObject (KeyedEventObject);
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return Status;
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}
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NTSTATUS
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NtWaitForKeyedEvent (
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IN HANDLE KeyedEventHandle,
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IN PVOID KeyValue,
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IN BOOLEAN Alertable,
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IN PLARGE_INTEGER Timeout OPTIONAL
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)
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/*++
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Routine Description:
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Wait on the keyed event for a specific release
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Arguments:
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KeyedEventHandle - Handle to a keyed event
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KeyValue - Value to be used to match the release thread against
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Alertable - Makes the wait alertable or not
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Timeout - Timeout value for wait
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Return Value:
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NTSTATUS - Status of call
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--*/
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{
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NTSTATUS Status;
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KPROCESSOR_MODE PreviousMode;
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PKEYED_EVENT_OBJECT KeyedEventObject;
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PETHREAD CurrentThread, TargetThread;
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PEPROCESS CurrentProcess;
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PLIST_ENTRY ListHead, ListEntry;
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LARGE_INTEGER TimeoutValue;
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PVOID OldKeyValue=NULL;
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if ((((ULONG_PTR)KeyValue) & KEYVALUE_RELEASE) != 0) {
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return STATUS_INVALID_PARAMETER_1;
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}
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CurrentThread = PsGetCurrentThread ();
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PreviousMode = KeGetPreviousModeByThread (&CurrentThread->Tcb);
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if (Timeout != NULL) {
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try {
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if (PreviousMode != KernelMode) {
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ProbeForRead (Timeout, sizeof (*Timeout), sizeof (UCHAR));
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}
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TimeoutValue = *Timeout;
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Timeout = &TimeoutValue;
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} except(ExSystemExceptionFilter ()) {
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return GetExceptionCode ();
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}
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}
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Status = ObReferenceObjectByHandle (KeyedEventHandle,
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KEYEDEVENT_WAIT,
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ExpKeyedEventObjectType,
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PreviousMode,
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&KeyedEventObject,
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NULL);
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if (!NT_SUCCESS (Status)) {
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return Status;
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}
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CurrentProcess = PsGetCurrentProcessByThread (CurrentThread);
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ListHead = &KeyedEventObject->WaitQueue;
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LOCK_KEYED_EVENT_EXCLUSIVE (KeyedEventObject, CurrentThread);
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ListEntry = ListHead->Flink;
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while (1) {
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TargetThread = CONTAINING_RECORD (ListEntry, ETHREAD, KeyedWaitChain);
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if (ListEntry == ListHead ||
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|
(((ULONG_PTR)(TargetThread->KeyedWaitValue))&KEYVALUE_RELEASE) == 0) {
|
|
//
|
|
// We could not find a key matching ours in the list so we must wait
|
|
//
|
|
OldKeyValue = CurrentThread->KeyedWaitValue;
|
|
CurrentThread->KeyedWaitValue = KeyValue;
|
|
|
|
//
|
|
// Insert the thread at the tail of the list. We establish an invariant
|
|
// were waiters are always at the back of the queue behind releasers to improve
|
|
// the wait code since it only has to search as far as the first non-release
|
|
// waiter.
|
|
//
|
|
InsertTailList (ListHead, &CurrentThread->KeyedWaitChain);
|
|
TargetThread = NULL;
|
|
break;
|
|
} else {
|
|
if (TargetThread->KeyedWaitValue == (PVOID)(((ULONG_PTR)KeyValue)|KEYVALUE_RELEASE) &&
|
|
THREAD_TO_PROCESS (TargetThread) == CurrentProcess) {
|
|
RemoveEntryList (ListEntry);
|
|
InitializeListHead (ListEntry);
|
|
break;
|
|
}
|
|
}
|
|
ListEntry = ListEntry->Flink;
|
|
}
|
|
//
|
|
// Release the lock but leave APC's disabled.
|
|
// This prevents us from being suspended and holding up the target.
|
|
//
|
|
UNLOCK_KEYED_EVENT_EXCLUSIVE_UNSAFE (KeyedEventObject);
|
|
|
|
if (TargetThread == NULL) {
|
|
KeLeaveCriticalRegionThread (&CurrentThread->Tcb);
|
|
Status = KeWaitForSingleObject (&CurrentThread->KeyedWaitSemaphore,
|
|
Executive,
|
|
PreviousMode,
|
|
Alertable,
|
|
Timeout);
|
|
//
|
|
// If we were woken by termination then we must manualy remove
|
|
// ourselves from the queue
|
|
//
|
|
if (Status != STATUS_SUCCESS) {
|
|
BOOLEAN Wait = TRUE;
|
|
|
|
LOCK_KEYED_EVENT_EXCLUSIVE (KeyedEventObject, CurrentThread);
|
|
if (!IsListEmpty (&CurrentThread->KeyedWaitChain)) {
|
|
RemoveEntryList (&CurrentThread->KeyedWaitChain);
|
|
InitializeListHead (&CurrentThread->KeyedWaitChain);
|
|
Wait = FALSE;
|
|
}
|
|
UNLOCK_KEYED_EVENT_EXCLUSIVE (KeyedEventObject, CurrentThread);
|
|
//
|
|
// If this thread was no longer in the queue then another thread
|
|
// must be about to wake us up. Wait for that wake.
|
|
//
|
|
if (Wait) {
|
|
KeWaitForSingleObject (&CurrentThread->KeyedWaitSemaphore,
|
|
Executive,
|
|
KernelMode,
|
|
FALSE,
|
|
NULL);
|
|
}
|
|
}
|
|
CurrentThread->KeyedWaitValue = OldKeyValue;
|
|
} else {
|
|
KeReleaseSemaphore (&TargetThread->KeyedWaitSemaphore,
|
|
SEMAPHORE_INCREMENT,
|
|
1,
|
|
FALSE);
|
|
KeLeaveCriticalRegionThread (&CurrentThread->Tcb);
|
|
}
|
|
|
|
ObDereferenceObject (KeyedEventObject);
|
|
|
|
return Status;
|
|
}
|