proc: replace cgo with syscalls on windows

Unrelated to conversion, I have also changed (*Thread).readMemory
to return only first count bytes of memory just as advised
by ReadProcessMemory.

Fixes #409
Fixes #412
Fixes #416

proc/proc_windows.go

@@ -1,7 +1,5 @@
 package proc
 
-// #include "windows.h"
-import "C"
 import (
 	"debug/gosym"
 	"debug/pe"
@@ -30,7 +28,7 @@ const (
 
 // OSProcessDetails holds Windows specific information.
 type OSProcessDetails struct {
-	hProcess    sys.Handle
+	hProcess    syscall.Handle
 	breakThread int
 }
 
@@ -121,17 +119,13 @@ func (dbp *Process) Kill() error {
 	// TODO: Should not have to ignore failures here,
 	// but some tests appear to Kill twice causing
 	// this to fail on second attempt.
-	_ = C.TerminateProcess(C.HANDLE(dbp.os.hProcess), 1)
+	_ = syscall.TerminateProcess(dbp.os.hProcess, 1)
 	dbp.exited = true
 	return nil
 }
 
 func (dbp *Process) requestManualStop() error {
-	res := C.DebugBreakProcess(C.HANDLE(dbp.os.hProcess))
+	return _DebugBreakProcess(dbp.os.hProcess)
-	if res == C.FALSE {
-		return fmt.Errorf("failed to break process %d", dbp.Pid)
-	}
-	return nil
 }
 
 func (dbp *Process) updateThreadList() error {
@@ -140,7 +134,7 @@ func (dbp *Process) updateThreadList() error {
 	return nil
 }
 
-func (dbp *Process) addThread(hThread sys.Handle, threadID int, attach bool) (*Thread, error) {
+func (dbp *Process) addThread(hThread syscall.Handle, threadID int, attach bool) (*Thread, error) {
 	if thread, ok := dbp.Threads[threadID]; ok {
 		return thread, nil
 	}
@@ -341,76 +335,76 @@ func dwarfFromPE(f *pe.File) (*dwarf.Data, error) {
 }
 
 func (dbp *Process) waitForDebugEvent() (threadID, exitCode int, err error) {
-	var debugEvent C.DEBUG_EVENT
+	var debugEvent _DEBUG_EVENT
 	shouldExit := false
 	for {
 		// Wait for a debug event...
-		res := C.WaitForDebugEvent(&debugEvent, C.INFINITE)
+		err := _WaitForDebugEvent(&debugEvent, syscall.INFINITE)
-		if res == C.FALSE {
+		if err != nil {
-			return 0, 0, fmt.Errorf("could not WaitForDebugEvent")
+			return 0, 0, err
 		}
 
 		// ... handle each event kind ...
-		unionPtr := unsafe.Pointer(&debugEvent.u[0])
+		unionPtr := unsafe.Pointer(&debugEvent.U[0])
-		switch debugEvent.dwDebugEventCode {
+		switch debugEvent.DebugEventCode {
-		case C.CREATE_PROCESS_DEBUG_EVENT:
+		case _CREATE_PROCESS_DEBUG_EVENT:
-			debugInfo := (*C.CREATE_PROCESS_DEBUG_INFO)(unionPtr)
+			debugInfo := (*_CREATE_PROCESS_DEBUG_INFO)(unionPtr)
-			hFile := debugInfo.hFile
+			hFile := debugInfo.File
-			if hFile != C.HANDLE(uintptr(0)) /* NULL */ && hFile != C.HANDLE(uintptr(0xFFFFFFFFFFFFFFFF)) /* INVALID_HANDLE_VALUE */ {
+			if hFile != 0 && hFile != syscall.InvalidHandle {
-				res = C.CloseHandle(hFile)
+				err = syscall.CloseHandle(hFile)
-				if res == C.FALSE {
+				if err != nil {
-					return 0, 0, fmt.Errorf("could not close create process file handle")
+					return 0, 0, err
 				}
 			}
-			dbp.os.hProcess = sys.Handle(debugInfo.hProcess)
+			dbp.os.hProcess = debugInfo.Process
-			_, err = dbp.addThread(sys.Handle(debugInfo.hThread), int(debugEvent.dwThreadId), false)
+			_, err = dbp.addThread(debugInfo.Thread, int(debugEvent.ThreadId), false)
 			if err != nil {
 				return 0, 0, err
 			}
 			break
-		case C.CREATE_THREAD_DEBUG_EVENT:
+		case _CREATE_THREAD_DEBUG_EVENT:
-			debugInfo := (*C.CREATE_THREAD_DEBUG_INFO)(unionPtr)
+			debugInfo := (*_CREATE_THREAD_DEBUG_INFO)(unionPtr)
-			_, err = dbp.addThread(sys.Handle(debugInfo.hThread), int(debugEvent.dwThreadId), false)
+			_, err = dbp.addThread(debugInfo.Thread, int(debugEvent.ThreadId), false)
 			if err != nil {
 				return 0, 0, err
 			}
 			break
-		case C.EXIT_THREAD_DEBUG_EVENT:
+		case _EXIT_THREAD_DEBUG_EVENT:
-			delete(dbp.Threads, int(debugEvent.dwThreadId))
+			delete(dbp.Threads, int(debugEvent.ThreadId))
 			break
-		case C.OUTPUT_DEBUG_STRING_EVENT:
+		case _OUTPUT_DEBUG_STRING_EVENT:
 			//TODO: Handle debug output strings
 			break
-		case C.LOAD_DLL_DEBUG_EVENT:
+		case _LOAD_DLL_DEBUG_EVENT:
-			debugInfo := (*C.LOAD_DLL_DEBUG_INFO)(unionPtr)
+			debugInfo := (*_LOAD_DLL_DEBUG_INFO)(unionPtr)
-			hFile := debugInfo.hFile
+			hFile := debugInfo.File
-			if hFile != C.HANDLE(uintptr(0)) /* NULL */ && hFile != C.HANDLE(uintptr(0xFFFFFFFFFFFFFFFF)) /* INVALID_HANDLE_VALUE */ {
+			if hFile != 0 && hFile != syscall.InvalidHandle {
-				res = C.CloseHandle(hFile)
+				err = syscall.CloseHandle(hFile)
-				if res == C.FALSE {
+				if err != nil {
-					return 0, 0, fmt.Errorf("could not close DLL load file handle")
+					return 0, 0, err
 				}
 			}
 			break
-		case C.UNLOAD_DLL_DEBUG_EVENT:
+		case _UNLOAD_DLL_DEBUG_EVENT:
 			break
-		case C.RIP_EVENT:
+		case _RIP_EVENT:
 			break
-		case C.EXCEPTION_DEBUG_EVENT:
+		case _EXCEPTION_DEBUG_EVENT:
-			tid := int(debugEvent.dwThreadId)
+			tid := int(debugEvent.ThreadId)
 			dbp.os.breakThread = tid
 			return tid, 0, nil
-		case C.EXIT_PROCESS_DEBUG_EVENT:
+		case _EXIT_PROCESS_DEBUG_EVENT:
-			debugInfo := (*C.EXIT_PROCESS_DEBUG_INFO)(unionPtr)
+			debugInfo := (*_EXIT_PROCESS_DEBUG_INFO)(unionPtr)
-			exitCode = int(debugInfo.dwExitCode)
+			exitCode = int(debugInfo.ExitCode)
 			shouldExit = true
 		default:
-			return 0, 0, fmt.Errorf("unknown debug event code: %d", debugEvent.dwDebugEventCode)
+			return 0, 0, fmt.Errorf("unknown debug event code: %d", debugEvent.DebugEventCode)
 		}
 
 		// .. and then continue unless we received an event that indicated we should break into debugger.
-		res = C.ContinueDebugEvent(debugEvent.dwProcessId, debugEvent.dwThreadId, C.DBG_CONTINUE)
+		err = _ContinueDebugEvent(debugEvent.ProcessId, debugEvent.ThreadId, _DBG_CONTINUE)
-		if res == C.WINBOOL(0) {
+		if err != nil {
-			return 0, 0, fmt.Errorf("could not ContinueDebugEvent")
+			return 0, 0, err
 		}
 
 		if shouldExit {

proc/registers_windows_amd64.go

@@ -1,12 +1,9 @@
 package proc
 
-// #include <windows.h>
-import "C"
 import (
 	"bytes"
 	"fmt"
 	"rsc.io/x86/x86asm"
-	"syscall"
 	"unsafe"
 )
 
@@ -97,22 +94,17 @@ func (r *Regs) TLS() uint64 {
 
 // SetPC sets the RIP register to the value specified by `pc`.
 func (r *Regs) SetPC(thread *Thread, pc uint64) error {
-	var context C.CONTEXT
+	context := newCONTEXT()
-	context.ContextFlags = C.CONTEXT_ALL
+	context.ContextFlags = _CONTEXT_ALL
 
-	res := C.GetThreadContext(C.HANDLE(thread.os.hThread), &context)
+	err := _GetThreadContext(thread.os.hThread, context)
-	if res == C.FALSE {
+	if err != nil {
-		return fmt.Errorf("could not GetThreadContext")
+		return err
 	}
 
-	context.Rip = C.DWORD64(pc)
+	context.Rip = pc
 
-	res = C.SetThreadContext(C.HANDLE(thread.os.hThread), &context)
+	return _SetThreadContext(thread.os.hThread, context)
-	if res == C.FALSE {
-		return fmt.Errorf("could not SetThreadContext")
-	}
-
-	return nil
 }
 
 func (r *Regs) Get(n int) (uint64, error) {
@@ -273,18 +265,18 @@ func (r *Regs) Get(n int) (uint64, error) {
 }
 
 func registers(thread *Thread) (Registers, error) {
-	var context C.CONTEXT
+	context := newCONTEXT()
 
-	context.ContextFlags = C.CONTEXT_ALL
+	context.ContextFlags = _CONTEXT_ALL
-	res := C.GetThreadContext(C.HANDLE(thread.os.hThread), &context)
+	err := _GetThreadContext(thread.os.hThread, context)
-	if res == C.FALSE {
+	if err != nil {
-		return nil, fmt.Errorf("failed to read ThreadContext")
+		return nil, err
 	}
 
 	var threadInfo _THREAD_BASIC_INFORMATION
-	status := _NtQueryInformationThread(syscall.Handle(thread.os.hThread), _ThreadBasicInformation, uintptr(unsafe.Pointer(&threadInfo)), uint32(unsafe.Sizeof(threadInfo)), nil)
+	status := _NtQueryInformationThread(thread.os.hThread, _ThreadBasicInformation, uintptr(unsafe.Pointer(&threadInfo)), uint32(unsafe.Sizeof(threadInfo)), nil)
 	if !_NT_SUCCESS(status) {
-		return nil, fmt.Errorf("failed to get thread_basic_information")
+		return nil, fmt.Errorf("NtQueryInformationThread failed: it returns 0x%x", status)
 	}
 
 	regs := &Regs{

proc/syscall_windows.go

@@ -22,8 +22,53 @@ type _THREAD_BASIC_INFORMATION struct {
 	BasePriority   int32
 }
 
+type _CREATE_PROCESS_DEBUG_INFO struct {
+	File                syscall.Handle
+	Process             syscall.Handle
+	Thread              syscall.Handle
+	BaseOfImage         uintptr
+	DebugInfoFileOffset uint32
+	DebugInfoSize       uint32
+	ThreadLocalBase     uintptr
+	StartAddress        uintptr
+	ImageName           uintptr
+	Unicode             uint16
+}
+
+type _CREATE_THREAD_DEBUG_INFO struct {
+	Thread          syscall.Handle
+	ThreadLocalBase uintptr
+	StartAddress    uintptr
+}
+
+type _EXIT_PROCESS_DEBUG_INFO struct {
+	ExitCode uint32
+}
+
+type _LOAD_DLL_DEBUG_INFO struct {
+	File                syscall.Handle
+	BaseOfDll           uintptr
+	DebugInfoFileOffset uint32
+	DebugInfoSize       uint32
+	ImageName           uintptr
+	Unicode             uint16
+}
+
 const (
 	_ThreadBasicInformation = 0
+
+	_DBG_CONTINUE              = 0x00010002
+	_DBG_EXCEPTION_NOT_HANDLED = 0x80010001
+
+	_EXCEPTION_DEBUG_EVENT      = 1
+	_CREATE_THREAD_DEBUG_EVENT  = 2
+	_CREATE_PROCESS_DEBUG_EVENT = 3
+	_EXIT_THREAD_DEBUG_EVENT    = 4
+	_EXIT_PROCESS_DEBUG_EVENT   = 5
+	_LOAD_DLL_DEBUG_EVENT       = 6
+	_UNLOAD_DLL_DEBUG_EVENT     = 7
+	_OUTPUT_DEBUG_STRING_EVENT  = 8
+	_RIP_EVENT                  = 9
 )
 
 func _NT_SUCCESS(x _NTSTATUS) bool {
@@ -31,3 +76,12 @@ func _NT_SUCCESS(x _NTSTATUS) bool {
 }
 
 //sys	_NtQueryInformationThread(threadHandle syscall.Handle, infoclass int32, info uintptr, infolen uint32, retlen *uint32) (status _NTSTATUS) = ntdll.NtQueryInformationThread
+//sys	_GetThreadContext(thread syscall.Handle, context *_CONTEXT) (err error) = kernel32.GetThreadContext
+//sys	_SetThreadContext(thread syscall.Handle, context *_CONTEXT) (err error) = kernel32.SetThreadContext
+//sys	_SuspendThread(threadid syscall.Handle) (prevsuspcount uint32, err error) [failretval==0xffffffff] = kernel32.SuspendThread
+//sys	_ResumeThread(threadid syscall.Handle) (prevsuspcount uint32, err error) [failretval==0xffffffff] = kernel32.ResumeThread
+//sys	_ContinueDebugEvent(processid uint32, threadid uint32, continuestatus uint32) (err error) = kernel32.ContinueDebugEvent
+//sys	_WriteProcessMemory(process syscall.Handle, baseaddr uintptr, buffer *byte, size uintptr, byteswritten *uintptr) (err error) = kernel32.WriteProcessMemory
+//sys	_ReadProcessMemory(process syscall.Handle, baseaddr uintptr, buffer *byte, size uintptr, bytesread *uintptr) (err error) = kernel32.ReadProcessMemory
+//sys	_DebugBreakProcess(process syscall.Handle) (err error) = kernel32.DebugBreakProcess
+//sys	_WaitForDebugEvent(debugevent *_DEBUG_EVENT, milliseconds uint32) (err error) = kernel32.WaitForDebugEvent

proc/syscall_windows_amd64.go

@@ -0,0 +1,95 @@
+package proc
+
+import "unsafe"
+
+const (
+	_CONTEXT_AMD64               = 0x100000
+	_CONTEXT_CONTROL             = (_CONTEXT_AMD64 | 0x1)
+	_CONTEXT_INTEGER             = (_CONTEXT_AMD64 | 0x2)
+	_CONTEXT_SEGMENTS            = (_CONTEXT_AMD64 | 0x4)
+	_CONTEXT_FLOATING_POINT      = (_CONTEXT_AMD64 | 0x8)
+	_CONTEXT_DEBUG_REGISTERS     = (_CONTEXT_AMD64 | 0x10)
+	_CONTEXT_FULL                = (_CONTEXT_CONTROL | _CONTEXT_INTEGER | _CONTEXT_FLOATING_POINT)
+	_CONTEXT_ALL                 = (_CONTEXT_CONTROL | _CONTEXT_INTEGER | _CONTEXT_SEGMENTS | _CONTEXT_FLOATING_POINT | _CONTEXT_DEBUG_REGISTERS)
+	_CONTEXT_EXCEPTION_ACTIVE    = 0x8000000
+	_CONTEXT_SERVICE_ACTIVE      = 0x10000000
+	_CONTEXT_EXCEPTION_REQUEST   = 0x40000000
+	_CONTEXT_EXCEPTION_REPORTING = 0x80000000
+)
+
+type _M128A struct {
+	Low  uint64
+	High int64
+}
+
+type _CONTEXT struct {
+	P1Home uint64
+	P2Home uint64
+	P3Home uint64
+	P4Home uint64
+	P5Home uint64
+	P6Home uint64
+
+	ContextFlags uint32
+	MxCsr        uint32
+
+	SegCs  uint16
+	SegDs  uint16
+	SegEs  uint16
+	SegFs  uint16
+	SegGs  uint16
+	SegSs  uint16
+	EFlags uint32
+
+	Dr0 uint64
+	Dr1 uint64
+	Dr2 uint64
+	Dr3 uint64
+	Dr6 uint64
+	Dr7 uint64
+
+	Rax uint64
+	Rcx uint64
+	Rdx uint64
+	Rbx uint64
+	Rsp uint64
+	Rbp uint64
+	Rsi uint64
+	Rdi uint64
+	R8  uint64
+	R9  uint64
+	R10 uint64
+	R11 uint64
+	R12 uint64
+	R13 uint64
+	R14 uint64
+	R15 uint64
+
+	Rip uint64
+
+	FltSave [512]byte
+
+	VectorRegister [26]_M128A
+	VectorControl  uint64
+
+	DebugControl         uint64
+	LastBranchToRip      uint64
+	LastBranchFromRip    uint64
+	LastExceptionToRip   uint64
+	LastExceptionFromRip uint64
+}
+
+// newCONTEXT allocates Windows CONTEXT structure aligned to 16 bytes.
+func newCONTEXT() *_CONTEXT {
+	var c *_CONTEXT
+	buf := make([]byte, unsafe.Sizeof(*c)+15)
+	return (*_CONTEXT)(unsafe.Pointer((uintptr(unsafe.Pointer(&buf[15]))) &^ 15))
+}
+
+type _DEBUG_EVENT struct {
+	DebugEventCode uint32
+	ProcessId      uint32
+	ThreadId       uint32
+	_              uint32 // to align Union properly
+	U              [160]byte
+}

proc/threads_windows.go

@@ -1,10 +1,8 @@
 package proc
 
-// #include <windows.h>
-import "C"
 import (
 	"fmt"
-	"unsafe"
+	"syscall"
 
 	sys "golang.org/x/sys/windows"
 )
@@ -15,7 +13,7 @@ type WaitStatus sys.WaitStatus
 // OSSpecificDetails holds information specific to the Windows
 // operating system / kernel.
 type OSSpecificDetails struct {
-	hThread sys.Handle
+	hThread syscall.Handle
 }
 
 func (t *Thread) halt() (err error) {
@@ -29,20 +27,20 @@ func (t *Thread) halt() (err error) {
 }
 
 func (t *Thread) singleStep() error {
-	var context C.CONTEXT
+	context := newCONTEXT()
-	context.ContextFlags = C.CONTEXT_ALL
+	context.ContextFlags = _CONTEXT_ALL
 
 	// Set the processor TRAP flag
-	res := C.GetThreadContext(C.HANDLE(t.os.hThread), &context)
+	err := _GetThreadContext(t.os.hThread, context)
-	if res == C.FALSE {
+	if err != nil {
-		return fmt.Errorf("could not GetThreadContext")
+		return err
 	}
 
 	context.EFlags |= 0x100
 
-	res = C.SetThreadContext(C.HANDLE(t.os.hThread), &context)
+	err = _SetThreadContext(t.os.hThread, context)
-	if res == C.FALSE {
+	if err != nil {
-		return fmt.Errorf("could not SetThreadContext")
+		return err
 	}
 
 	// Suspend all threads except this one
@@ -50,20 +48,21 @@ func (t *Thread) singleStep() error {
 		if thread.ID == t.ID {
 			continue
 		}
-		res := C.SuspendThread(C.HANDLE(thread.os.hThread))
+		_, err := _SuspendThread(thread.os.hThread)
-		if res == C.DWORD(0xFFFFFFFF) {
+		if err != nil {
-			return fmt.Errorf("could not suspend thread: %d", thread.ID)
+			return fmt.Errorf("could not suspend thread: %d: %v", thread.ID, err)
 		}
 	}
 
 	// Continue and wait for the step to complete
+	err = nil
 	t.dbp.execPtraceFunc(func() {
-		res = C.ContinueDebugEvent(C.DWORD(t.dbp.Pid), C.DWORD(t.ID), C.DBG_CONTINUE)
+		err = _ContinueDebugEvent(uint32(t.dbp.Pid), uint32(t.ID), _DBG_CONTINUE)
 	})
-	if res == C.FALSE {
+	if err != nil {
-		return fmt.Errorf("could not ContinueDebugEvent.")
+		return err
 	}
-	_, err := t.dbp.trapWait(0)
+	_, err = t.dbp.trapWait(0)
 	if err != nil {
 		return err
 	}
@@ -73,40 +72,32 @@ func (t *Thread) singleStep() error {
 		if thread.ID == t.ID {
 			continue
 		}
-		res := C.ResumeThread(C.HANDLE(thread.os.hThread))
+		_, err := _ResumeThread(thread.os.hThread)
-		if res == C.DWORD(0xFFFFFFFF) {
+		if err != nil {
-			return fmt.Errorf("ould not resume thread: %d", thread.ID)
+			return fmt.Errorf("could not resume thread: %d: %v", thread.ID, err)
 		}
 	}
 
 	// Unset the processor TRAP flag
-	res = C.GetThreadContext(C.HANDLE(t.os.hThread), &context)
+	err = _GetThreadContext(t.os.hThread, context)
-	if res == C.FALSE {
+	if err != nil {
-		return fmt.Errorf("could not GetThreadContext")
+		return err
 	}
 
-	context.EFlags &= ^C.DWORD(0x100)
+	context.EFlags &= ^uint32(0x100)
 
-	res = C.SetThreadContext(C.HANDLE(t.os.hThread), &context)
+	return _SetThreadContext(t.os.hThread, context)
-	if res == C.FALSE {
-		return fmt.Errorf("could not SetThreadContext")
-	}
-
-	return nil
 }
 
 func (t *Thread) resume() error {
 	t.running = true
-	var res C.WINBOOL
+	var err error
 	t.dbp.execPtraceFunc(func() {
 		//TODO: Note that we are ignoring the thread we were asked to continue and are continuing the
 		//thread that we last broke on.
-		res = C.ContinueDebugEvent(C.DWORD(t.dbp.Pid), C.DWORD(t.ID), C.DBG_CONTINUE)
+		err = _ContinueDebugEvent(uint32(t.dbp.Pid), uint32(t.ID), _DBG_CONTINUE)
 	})
-	if res == C.FALSE {
+	return err
-		return fmt.Errorf("could not ContinueDebugEvent.")
-	}
-	return nil
 }
 
 func (t *Thread) blocked() bool {
@@ -135,15 +126,10 @@ func (t *Thread) stopped() bool {
 }
 
 func (t *Thread) writeMemory(addr uintptr, data []byte) (int, error) {
-	var (
+	var count uintptr
-		vmData = C.LPCVOID(unsafe.Pointer(&data[0]))
+	err := _WriteProcessMemory(t.dbp.os.hProcess, addr, &data[0], uintptr(len(data)), &count)
-		vmAddr = C.LPVOID(addr)
+	if err != nil {
-		length = C.SIZE_T(len(data))
+		return 0, err
-		count  C.SIZE_T
-	)
-	ret := C.WriteProcessMemory(C.HANDLE(t.dbp.os.hProcess), vmAddr, vmData, length, &count)
-	if ret == C.FALSE {
-		return int(count), fmt.Errorf("could not write memory")
 	}
 	return int(count), nil
 }
@@ -152,16 +138,11 @@ func (t *Thread) readMemory(addr uintptr, size int) ([]byte, error) {
 	if size == 0 {
 		return nil, nil
 	}
-	var (
+	var count uintptr
-		buf    = make([]byte, size)
+	buf := make([]byte, size)
-		vmData = C.LPVOID(unsafe.Pointer(&buf[0]))
+	err := _ReadProcessMemory(t.dbp.os.hProcess, addr, &buf[0], uintptr(size), &count)
-		vmAddr = C.LPCVOID(addr)
+	if err != nil {
-		length = C.SIZE_T(size)
+		return nil, err
-		count  C.SIZE_T
-	)
-	ret := C.ReadProcessMemory(C.HANDLE(t.dbp.os.hProcess), vmAddr, vmData, length, &count)
-	if ret == C.FALSE {
-		return nil, fmt.Errorf("could not read memory")
 	}
-	return buf, nil
+	return buf[:count], nil
 }

proc/zsyscall_windows.go

@@ -8,9 +8,19 @@ import "syscall"
 var _ unsafe.Pointer
 
 var (
-	modntdll = syscall.NewLazyDLL("ntdll.dll")
+	modntdll    = syscall.NewLazyDLL("ntdll.dll")
+	modkernel32 = syscall.NewLazyDLL("kernel32.dll")
 
 	procNtQueryInformationThread = modntdll.NewProc("NtQueryInformationThread")
+	procGetThreadContext         = modkernel32.NewProc("GetThreadContext")
+	procSetThreadContext         = modkernel32.NewProc("SetThreadContext")
+	procSuspendThread            = modkernel32.NewProc("SuspendThread")
+	procResumeThread             = modkernel32.NewProc("ResumeThread")
+	procContinueDebugEvent       = modkernel32.NewProc("ContinueDebugEvent")
+	procWriteProcessMemory       = modkernel32.NewProc("WriteProcessMemory")
+	procReadProcessMemory        = modkernel32.NewProc("ReadProcessMemory")
+	procDebugBreakProcess        = modkernel32.NewProc("DebugBreakProcess")
+	procWaitForDebugEvent        = modkernel32.NewProc("WaitForDebugEvent")
 )
 
 func _NtQueryInformationThread(threadHandle syscall.Handle, infoclass int32, info uintptr, infolen uint32, retlen *uint32) (status _NTSTATUS) {
@@ -18,3 +28,113 @@ func _NtQueryInformationThread(threadHandle syscall.Handle, infoclass int32, inf
 	status = _NTSTATUS(r0)
 	return
 }
+
+func _GetThreadContext(thread syscall.Handle, context *_CONTEXT) (err error) {
+	r1, _, e1 := syscall.Syscall(procGetThreadContext.Addr(), 2, uintptr(thread), uintptr(unsafe.Pointer(context)), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func _SetThreadContext(thread syscall.Handle, context *_CONTEXT) (err error) {
+	r1, _, e1 := syscall.Syscall(procSetThreadContext.Addr(), 2, uintptr(thread), uintptr(unsafe.Pointer(context)), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func _SuspendThread(threadid syscall.Handle) (prevsuspcount uint32, err error) {
+	r0, _, e1 := syscall.Syscall(procSuspendThread.Addr(), 1, uintptr(threadid), 0, 0)
+	prevsuspcount = uint32(r0)
+	if prevsuspcount == 0xffffffff {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func _ResumeThread(threadid syscall.Handle) (prevsuspcount uint32, err error) {
+	r0, _, e1 := syscall.Syscall(procResumeThread.Addr(), 1, uintptr(threadid), 0, 0)
+	prevsuspcount = uint32(r0)
+	if prevsuspcount == 0xffffffff {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func _ContinueDebugEvent(processid uint32, threadid uint32, continuestatus uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procContinueDebugEvent.Addr(), 3, uintptr(processid), uintptr(threadid), uintptr(continuestatus))
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func _WriteProcessMemory(process syscall.Handle, baseaddr uintptr, buffer *byte, size uintptr, byteswritten *uintptr) (err error) {
+	r1, _, e1 := syscall.Syscall6(procWriteProcessMemory.Addr(), 5, uintptr(process), uintptr(baseaddr), uintptr(unsafe.Pointer(buffer)), uintptr(size), uintptr(unsafe.Pointer(byteswritten)), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func _ReadProcessMemory(process syscall.Handle, baseaddr uintptr, buffer *byte, size uintptr, bytesread *uintptr) (err error) {
+	r1, _, e1 := syscall.Syscall6(procReadProcessMemory.Addr(), 5, uintptr(process), uintptr(baseaddr), uintptr(unsafe.Pointer(buffer)), uintptr(size), uintptr(unsafe.Pointer(bytesread)), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func _DebugBreakProcess(process syscall.Handle) (err error) {
+	r1, _, e1 := syscall.Syscall(procDebugBreakProcess.Addr(), 1, uintptr(process), 0, 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func _WaitForDebugEvent(debugevent *_DEBUG_EVENT, milliseconds uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procWaitForDebugEvent.Addr(), 2, uintptr(unsafe.Pointer(debugevent)), uintptr(milliseconds), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}