How to get thread stack information on Windows?

Question

I enumerate all threads in a process through the CreateToolhelp32Snapshot function. I would like to get some basic stack information for each thread. More specifically I would like to get stack bottom address and if possible I would like to get current stack top address. Basically this is the information displayed with the ~*k command in WinDbg. So how can I obtain the stack information from the thread's ID or HANDLE?

Answer 1

(Definitions can be found here.)

To get stack boundaries:

THREAD_BASIC_INFORMATION basicInfo;
NT_TIB tib;

// Get TEB address
NtQueryInformationThread(YOUR_THREAD_HANDLE, ThreadBasicInformation, &basicInfo, sizeof(THREAD_BASIC_INFORMATION), NULL);
// Read TIB
NtReadVirtualMemory(YOUR_PROCESS_HANDLE, basicInfo.TebBaseAddress, &tib, sizeof(NT_TIB), NULL);
// Check tib.StackBase and tib.StackLimit

To get the value of esp, simply use GetThreadContext.

Answer 2

An easier way without having to involve the Windows Driver Kit is as so:

NT_TIB* tib = (NT_TIB*)__readfsdword(0x18);
size_t* stackBottom = (size_t*)tib->StackLimit;
size_t* stackTop = (size_t*)tib->StackBase;

Answer 3

__readfsdword() works only for the current thread. So, the variant with NtQueryInformationThread() is more flexible.

Added some declarations which are missed in ntdll.h:

typedef enum _THREADINFOCLASS {
    ThreadBasicInformation = 0,
} THREADINFOCLASS;

typedef LONG KPRIORITY;

typedef struct _CLIENT_ID {
    HANDLE UniqueProcess;
    HANDLE UniqueThread;
} CLIENT_ID;
typedef CLIENT_ID *PCLIENT_ID;

typedef struct _THREAD_BASIC_INFORMATION
{
  NTSTATUS                ExitStatus;
  PVOID                   TebBaseAddress;
  CLIENT_ID               ClientId;
  KAFFINITY               AffinityMask;
  KPRIORITY               Priority;
  KPRIORITY               BasePriority;
} THREAD_BASIC_INFORMATION, *PTHREAD_BASIC_INFORMATION;

Answer 4

As fas as I know, Toolhelp works by making a copy of basic information on heaps, modules, processes and threads. This does not include the TEB block that contains the stack bottom address. I think you need to use another API, the debugger engine API, which offers functions to examine the stacks