How to get thread stack information on Windows?
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. B开发者_开发问答asically 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?
(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
.
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;
__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;
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
Here's an easy way for the current thread (portable Win32 x86/x64 version):
#include <intrin.h>
NT_TIB* getTIB() {
#ifdef _M_IX86
return (NT_TIB*)__readfsdword(0x18);
#elif _M_AMD64
return (NT_TIB*)__readgsqword(0x30);
#else
#error unsupported architecture
#endif
}
NT_TIB* tib = getTIB();
void* stackBase = tib->StackBase;
void* stackLimit = tib->StackLimit;
Note: stackLimit
< stackBase
(as stack grows downwards).
For more details refer to Win32 TIB.
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