#ifndef _NTPEBTEB_H

/**
 * Thread Environment Block (TEB) structure.
 *
 * \sa https://learn.microsoft.com/en-us/windows/win32/api/winternl/ns-winternl-teb
 */
typedef struct _TEB
{
    //
    // Thread Information Block (TIB) contains the thread's stack, base and limit addresses, the current stack pointer, and the exception list.
    //
    NT_TIB NtTib;

    //
    // Reserved.
    //
    PVOID EnvironmentPointer;

    //
    // Client ID for this thread.
    //
    CLIENT_ID ClientId;

    //
    // A handle to an active Remote Procedure Call (RPC) if the thread is currently involved in an RPC operation.
    //
    PVOID ActiveRpcHandle;

    //
    // A pointer to the __declspec(thread) local storage array.
    //
    PVOID ThreadLocalStoragePointer;

    //
    // A pointer to the Process Environment Block (PEB), which contains information about the process.
    //
    PPEB ProcessEnvironmentBlock;

    //
    // The previous Win32 error value for this thread.
    //
    ULONG LastErrorValue;

    //
    // The number of critical sections currently owned by this thread.
    //
    ULONG CountOfOwnedCriticalSections;

    //
    // Reserved.
    //
    PVOID CsrClientThread;

    //
    // Reserved for win32k.sys
    //
    PVOID Win32ThreadInfo;
 
    //
    // Reserved for user32.dll
    //
    ULONG User32Reserved[26];

    //
    // Reserved for winsrv.dll
    //
    ULONG UserReserved[5];

    //
    // Reserved.
    //
    PVOID WOW32Reserved;

    //
    // The LCID of the current thread. (Kernel32!GetThreadLocale)
    //
    LCID CurrentLocale;

    //
    // Reserved.
    //
    ULONG FpSoftwareStatusRegister;

    //
    // Reserved.
    //
    PVOID ReservedForDebuggerInstrumentation[16];

#ifdef _WIN64
    //
    // Reserved for floating-point emulation.
    //
    PVOID SystemReserved1[25];

    //
    // Per-thread fiber local storage. (Teb->HasFiberData)
    //
    PVOID HeapFlsData;

    //
    // Reserved.
    //
    ULONG_PTR RngState[4];
#else
    //
    // Reserved.
    //
    PVOID SystemReserved1[26];
#endif

    //
    // Placeholder compatibility mode. (ProjFs and Cloud Files)
    //
    CHAR PlaceholderCompatibilityMode;

    //
    // Indicates whether placeholder hydration is always explicit.
    //
    BOOLEAN PlaceholderHydrationAlwaysExplicit;

    //
    // ProjFs and Cloud Files (reparse point) file virtualization.
    //
    CHAR PlaceholderReserved[10];

    //
    // The process ID (PID) that the current COM server thread is acting on behalf of.
    //
    ULONG ProxiedProcessId;

    //
    // Pointer to the activation context stack for the current thread.
    //
    ACTIVATION_CONTEXT_STACK ActivationStack;

    //
    // Opaque operation on behalf of another user or process.
    //
    UCHAR WorkingOnBehalfTicket[8];

    //
    // The last exception status for the current thread.
    //
    NTSTATUS ExceptionCode;

    //
    // Pointer to the activation context stack for the current thread.
    //
    PACTIVATION_CONTEXT_STACK ActivationContextStackPointer;

    //
    // The stack pointer (SP) of the current system call or exception during instrumentation.
    //
    ULONG_PTR InstrumentationCallbackSp;

    //
    // The program counter (PC) of the previous system call or exception during instrumentation.
    //
    ULONG_PTR InstrumentationCallbackPreviousPc;

    //
    // The stack pointer (SP) of the previous system call or exception during instrumentation.
    //
    ULONG_PTR InstrumentationCallbackPreviousSp;

#ifdef _WIN64
    //
    // The miniversion ID of the current transacted file operation.
    //
    ULONG TxFsContext;
#endif

    //
    // Indicates the state of the system call or exception instrumentation callback.
    //
    BOOLEAN InstrumentationCallbackDisabled;

#ifdef _WIN64
    //
    // Indicates the state of alignment exceptions for unaligned load/store operations.
    //
    BOOLEAN UnalignedLoadStoreExceptions;
#endif

#ifndef _WIN64
    //
    // SpareBytes.
    //
    UCHAR SpareBytes[23];

    //
    // The miniversion ID of the current transacted file operation.
    //
    ULONG TxFsContext;
#endif

    //
    // Reserved for GDI (Win32k).
    //
    GDI_TEB_BATCH GdiTebBatch;
    CLIENT_ID RealClientId;
    HANDLE GdiCachedProcessHandle;
    ULONG GdiClientPID;
    ULONG GdiClientTID;
    PVOID GdiThreadLocalInfo;

    //
    // Reserved for User32 (Win32k).
    //
    ULONG_PTR Win32ClientInfo[WIN32_CLIENT_INFO_LENGTH];

    //
    // Reserved for opengl32.dll
    //
    PVOID glDispatchTable[233];
    ULONG_PTR glReserved1[29];
    PVOID glReserved2;
    PVOID glSectionInfo;
    PVOID glSection;
    PVOID glTable;
    PVOID glCurrentRC;
    PVOID glContext;

    //
    // The previous status value for this thread.
    //
    NTSTATUS LastStatusValue;

    //
    // A static string for use by the application.
    //
    UNICODE_STRING StaticUnicodeString;

    //
    // A static buffer for use by the application.
    //
    WCHAR StaticUnicodeBuffer[STATIC_UNICODE_BUFFER_LENGTH];

    //
    // The maximum stack size and indicates the base of the stack.
    //
    PVOID DeallocationStack;

    //
    // Data for Thread Local Storage. (TlsGetValue)
    //
    PVOID TlsSlots[TLS_MINIMUM_AVAILABLE];

    //
    // Reserved for TLS.
    //
    LIST_ENTRY TlsLinks;

    //
    // Reserved for NTVDM.
    //
    PVOID Vdm;

    //
    // Reserved for RPC. The pointer is XOR'ed with RPC_THREAD_POINTER_KEY.
    //
    PVOID ReservedForNtRpc;

    //
    // Reserved for Debugging (DebugActiveProcess).
    //
    PVOID DbgSsReserved[2];

    //
    // The error mode for the current thread. (GetThreadErrorMode)
    //
    ULONG HardErrorMode;

    //
    // Reserved.
    //
#ifdef _WIN64
    PVOID Instrumentation[11];
#else
    PVOID Instrumentation[9];
#endif

    //
    // Reserved.
    //
    GUID ActivityId;

    //
    // The identifier of the service that created the thread. (svchost)
    //
    PVOID SubProcessTag;

    //
    // Reserved.
    //
    PVOID PerflibData;

    //
    // Reserved.
    //
    PVOID EtwTraceData;

    //
    // The address of a socket handle during a blocking socket operation. (WSAStartup)
    //
    HANDLE WinSockData;

    //
    // The number of function calls accumulated in the current GDI batch. (GdiSetBatchLimit)
    //
    ULONG GdiBatchCount;

    //
    // The preferred processor for the current thread. (SetThreadIdealProcessor/SetThreadIdealProcessorEx)
    //
    union
    {
        PROCESSOR_NUMBER CurrentIdealProcessor;
        ULONG IdealProcessorValue;
        struct
        {
            UCHAR ReservedPad0;
            UCHAR ReservedPad1;
            UCHAR ReservedPad2;
            UCHAR IdealProcessor;
        };
    };

    //
    // The minimum size of the stack available during any stack overflow exceptions. (SetThreadStackGuarantee)
    //
    ULONG GuaranteedStackBytes;

    //
    // Reserved.
    //
    PVOID ReservedForPerf;

    //
    // Reserved for Object Linking and Embedding (OLE)
    //
    PSOleTlsData ReservedForOle;

    //
    // Indicates whether the thread is waiting on the loader lock.
    //
    ULONG WaitingOnLoaderLock;

    //
    // The saved priority state for the thread.
    //
    PVOID SavedPriorityState;

    //
    // Reserved.
    //
    ULONG_PTR ReservedForCodeCoverage;

    //
    // Reserved.
    //
    PVOID ThreadPoolData;

    //
    // Pointer to the TLS (Thread Local Storage) expansion slots for the thread.
    //
    PVOID *TlsExpansionSlots;

#ifdef _WIN64
    PVOID ChpeV2CpuAreaInfo; // CHPEV2_CPUAREA_INFO // previously DeallocationBStore
    PVOID Unused; // previously BStoreLimit
#endif

    //
    // The generation of the MUI (Multilingual User Interface) data.
    //
    ULONG MuiGeneration;

    //
    // Indicates whether the thread is impersonating another security context.
    //
    ULONG IsImpersonating;

    //
    // Pointer to the NLS (National Language Support) cache.
    //
    PVOID NlsCache;

    //
    // Pointer to the AppCompat/Shim Engine data.
    //
    PVOID pShimData;

    //
    // Reserved.
    //
    ULONG HeapData;

    //
    // Handle to the current transaction associated with the thread.
    //
    HANDLE CurrentTransactionHandle;

    //
    // Pointer to the active frame for the thread.
    //
    PTEB_ACTIVE_FRAME ActiveFrame;

    //
    // Reserved for FLS (RtlProcessFlsData).
    //
    PVOID FlsData;

    //
    // Pointer to the preferred languages for the current thread. (GetThreadPreferredUILanguages)
    //
    PVOID PreferredLanguages;

    //
    // Pointer to the user-preferred languages for the current thread. (GetUserPreferredUILanguages)
    //
    PVOID UserPrefLanguages;

    //
    // Pointer to the merged preferred languages for the current thread. (MUI_MERGE_USER_FALLBACK)
    //
    PVOID MergedPrefLanguages;

    //
    // Indicates whether the thread is impersonating another user's language settings.
    //
    ULONG MuiImpersonation;

    //
    // Reserved.
    //
    union
    {
        USHORT CrossTebFlags;
        USHORT SpareCrossTebBits : 16;
    };

    //
    // SameTebFlags modify the state and behavior of the current thread.
    //
    union
    {
        USHORT SameTebFlags;
        struct
        {
            USHORT SafeThunkCall : 1;
            USHORT InDebugPrint : 1;            // Indicates if the thread is currently in a debug print routine.
            USHORT HasFiberData : 1;            // Indicates if the thread has local fiber-local storage (FLS).
            USHORT SkipThreadAttach : 1;        // Indicates if the thread should suppress DLL_THREAD_ATTACH notifications.
            USHORT WerInShipAssertCode : 1;
            USHORT RanProcessInit : 1;          // Indicates if the thread has run process initialization code.
            USHORT ClonedThread : 1;            // Indicates if the thread is a clone of a different thread.
            USHORT SuppressDebugMsg : 1;        // Indicates if the thread should suppress LOAD_DLL_DEBUG_INFO notifications.
            USHORT DisableUserStackWalk : 1;
            USHORT RtlExceptionAttached : 1;
            USHORT InitialThread : 1;           // Indicates if the thread is the initial thread of the process.
            USHORT SessionAware : 1;
            USHORT LoadOwner : 1;               // Indicates if the thread is the owner of the process loader lock.
            USHORT LoaderWorker : 1;
            USHORT SkipLoaderInit : 1;
            USHORT SkipFileAPIBrokering : 1;
        };
    };

    //
    // Pointer to the callback function that is called when a KTM transaction scope is entered.
    //
    PVOID TxnScopeEnterCallback;

    //
    // Pointer to the callback function that is called when a KTM transaction scope is exited.
    ///
    PVOID TxnScopeExitCallback;

    //
    // Pointer to optional context data for use by the application when a KTM transaction scope callback is called.
    //
    PVOID TxnScopeContext;

    //
    // The lock count of critical sections for the current thread.
    //
    ULONG LockCount;

    //
    // The offset to the WOW64 (Windows on Windows) TEB for the current thread.
    //
    LONG WowTebOffset;

    //
    // Pointer to the DLL containing the resource (valid after LdrFindResource_U/LdrResFindResource/etc... returns).
    //
    PLDR_RESLOADER_RET ResourceRetValue;

    //
    // Reserved for Windows Driver Framework (WDF).
    //
    PVOID ReservedForWdf;

    //
    // Reserved for the Microsoft C runtime (CRT).
    //
    ULONGLONG ReservedForCrt;

    //
    // The Host Compute Service (HCS) container identifier.
    //
    GUID EffectiveContainerId;

    //
    // Reserved for Kernel32!Sleep (SpinWait).
    //
    ULONGLONG LastSleepCounter; // since Win11

    //
    // Reserved for Kernel32!Sleep (SpinWait).
    //
    ULONG SpinCallCount;

    //
    // Extended feature disable mask (AVX).
    //
    ULONGLONG ExtendedFeatureDisableMask;

    //
    // Reserved.
    //
    PVOID SchedulerSharedDataSlot; // since 24H2

    //
    // Reserved.
    //
    PVOID HeapWalkContext;

    //
    // The primary processor group affinity of the thread.
    //
    GROUP_AFFINITY PrimaryGroupAffinity;

    //
    // Read-copy-update (RCU) synchronization context.
    //
    ULONG Rcu[2];
} TEB, *PTEB;

#endif
View code on GitHub

// winternl.h

typedef struct _TEB {
  PVOID Reserved1[12];
  PPEB  ProcessEnvironmentBlock;
  PVOID Reserved2[399];
  BYTE  Reserved3[1952];
  PVOID TlsSlots[64];
  BYTE  Reserved4[8];
  PVOID Reserved5[26];
  PVOID ReservedForOle;
  PVOID Reserved6[4];
  PVOID TlsExpansionSlots;
} TEB, *PTEB;
View the official Win32 API reference