KDHELP structure (dbghelp.h)

Information that is used by kernel debuggers to trace through user-mode callbacks in a thread's kernel stack.

Syntax

typedef struct _KDHELP {
  DWORD Thread;
  DWORD ThCallbackStack;
  DWORD NextCallback;
  DWORD FramePointer;
  DWORD KiCallUserMode;
  DWORD KeUserCallbackDispatcher;
  DWORD SystemRangeStart;
  DWORD ThCallbackBStore;
  DWORD KiUserExceptionDispatcher;
  DWORD StackBase;
  DWORD StackLimit;
  DWORD Reserved[5];
} KDHELP, *PKDHELP;

Members

Thread

The address of the kernel thread object, as provided in the WAIT_STATE_CHANGE packet.

ThCallbackStack

The offset in the thread object to the pointer to the current callback frame in the kernel stack.

NextCallback

The address of the next callback frame.

FramePointer

The address of the saved frame pointer, if applicable.

KiCallUserMode

The address of the kernel function that calls out to user mode.

KeUserCallbackDispatcher

The address of the user-mode dispatcher function.

SystemRangeStart

The lowest kernel-mode address.

ThCallbackBStore

Intel Itanium:  The offset in the thread object to a pointer to the current callback backing store frame in the kernel stack.

KiUserExceptionDispatcher

The address of the user-mode exception dispatcher function.

DbgHelp 6.1 and earlier:  This member is not supported.

StackBase

The address of the stack base.

StackLimit

The stack limit.

Reserved[5]

This member is reserved for use by the operating system.

Remarks

This structure supersedes the KDHELP structure. For more information, see Updated Platform Support. KDHELP is defined as follows in Dbghelp.h.

#if !defined(_IMAGEHLP_SOURCE_) && defined(_IMAGEHLP64)
#define KDHELP KDHELP64
#define PKDHELP PKDHELP64
#else
typedef struct _KDHELP {
    DWORD   Thread;
    DWORD   ThCallbackStack;
    DWORD   NextCallback;
    DWORD   FramePointer;
    DWORD   KiCallUserMode;
    DWORD   KeUserCallbackDispatcher;
    DWORD   SystemRangeStart;
    DWORD   ThCallbackBStore;
    DWORD   KiUserExceptionDispatcher;
    DWORD   StackBase;
    DWORD   StackLimit;
    DWORD   Reserved[5];
} KDHELP, *PKDHELP;
#endif

Requirements

Requirement	Value
Header	dbghelp.h
Redistributable	DbgHelp.dll 5.1 or later

See also

STACKFRAME64