windows: add definitions and functions for ProcThreadAttributeList

The bulk of the documentation for these is in:

https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-updateprocthreadattribute

This allows creating processes from scratch that use advanced options,
such as changing the process parent.

Fixes golang/go#44005.

Change-Id: Id5cc5400541e57710b9e888cd37ef4f925d510fe
Reviewed-on: https://go-review.googlesource.com/c/sys/+/288412
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Trust: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

windows/exec_windows.go

@@ -6,6 +6,11 @@
 
 package windows
 
+import (
+	errorspkg "errors"
+	"unsafe"
+)
+
 // EscapeArg rewrites command line argument s as prescribed
 // in http://msdn.microsoft.com/en-us/library/ms880421.
 // This function returns "" (2 double quotes) if s is empty.
@@ -95,3 +100,31 @@ func FullPath(name string) (path string, err error) {
 		}
 	}
 }
+
+// NewProcThreadAttributeList allocates a new ProcThreadAttributeList, with the requested maximum number of attributes.
+func NewProcThreadAttributeList(maxAttrCount uint32) (*ProcThreadAttributeList, error) {
+	var size uintptr
+	err := initializeProcThreadAttributeList(nil, maxAttrCount, 0, &size)
+	if err != ERROR_INSUFFICIENT_BUFFER {
+		if err == nil {
+			return nil, errorspkg.New("unable to query buffer size from InitializeProcThreadAttributeList")
+		}
+		return nil, err
+	}
+	al := (*ProcThreadAttributeList)(unsafe.Pointer(&make([]byte, size)[0]))
+	err = initializeProcThreadAttributeList(al, maxAttrCount, 0, &size)
+	if err != nil {
+		return nil, err
+	}
+	return al, err
+}
+
+// Update modifies the ProcThreadAttributeList using UpdateProcThreadAttribute.
+func (al *ProcThreadAttributeList) Update(attribute uintptr, flags uint32, value unsafe.Pointer, size uintptr, prevValue uintptr, returnedSize *uintptr) error {
+	return updateProcThreadAttribute(al, flags, attribute, uintptr(value), size, prevValue, returnedSize)
+}
+
+// Delete frees ProcThreadAttributeList's resources.
+func (al *ProcThreadAttributeList) Delete() {
+	deleteProcThreadAttributeList(al)
+}

windows/syscall_windows.go

@@ -214,6 +214,9 @@ func NewCallbackCDecl(fn interface{}) uintptr {
 //sys	CancelIo(s Handle) (err error)
 //sys	CancelIoEx(s Handle, o *Overlapped) (err error)
 //sys	CreateProcess(appName *uint16, commandLine *uint16, procSecurity *SecurityAttributes, threadSecurity *SecurityAttributes, inheritHandles bool, creationFlags uint32, env *uint16, currentDir *uint16, startupInfo *StartupInfo, outProcInfo *ProcessInformation) (err error) = CreateProcessW
+//sys   initializeProcThreadAttributeList(attrlist *ProcThreadAttributeList, attrcount uint32, flags uint32, size *uintptr) (err error) = InitializeProcThreadAttributeList
+//sys   deleteProcThreadAttributeList(attrlist *ProcThreadAttributeList) = DeleteProcThreadAttributeList
+//sys   updateProcThreadAttribute(attrlist *ProcThreadAttributeList, flags uint32, attr uintptr, value uintptr, size uintptr, prevvalue uintptr, returnedsize *uintptr) (err error) = UpdateProcThreadAttribute
 //sys	OpenProcess(desiredAccess uint32, inheritHandle bool, processId uint32) (handle Handle, err error)
 //sys	ShellExecute(hwnd Handle, verb *uint16, file *uint16, args *uint16, cwd *uint16, showCmd int32) (err error) [failretval<=32] = shell32.ShellExecuteW
 //sys	GetWindowThreadProcessId(hwnd HWND, pid *uint32) (tid uint32, err error) = user32.GetWindowThreadProcessId

windows/types_windows.go

@@ -215,6 +215,18 @@ const (
 	INHERIT_PARENT_AFFINITY          = 0x00010000
 )
 
+const (
+	// attributes for ProcThreadAttributeList
+	PROC_THREAD_ATTRIBUTE_PARENT_PROCESS    = 0x00020000
+	PROC_THREAD_ATTRIBUTE_HANDLE_LIST       = 0x00020002
+	PROC_THREAD_ATTRIBUTE_GROUP_AFFINITY    = 0x00030003
+	PROC_THREAD_ATTRIBUTE_PREFERRED_NODE    = 0x00020004
+	PROC_THREAD_ATTRIBUTE_IDEAL_PROCESSOR   = 0x00030005
+	PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY = 0x00020007
+	PROC_THREAD_ATTRIBUTE_UMS_THREAD        = 0x00030006
+	PROC_THREAD_ATTRIBUTE_PROTECTION_LEVEL  = 0x0002000b
+)
+
 const (
 	// flags for CreateToolhelp32Snapshot
 	TH32CS_SNAPHEAPLIST = 0x01
@@ -886,6 +898,19 @@ type StartupInfo struct {
 	StdErr        Handle
 }
 
+type StartupInfoEx struct {
+	StartupInfo
+	ProcThreadAttributeList *ProcThreadAttributeList
+}
+
+// ProcThreadAttributeList is a placeholder type to represent a PROC_THREAD_ATTRIBUTE_LIST.
+//
+// To create a *ProcThreadAttributeList, use NewProcThreadAttributeList, and
+// free its memory using ProcThreadAttributeList.Delete.
+type ProcThreadAttributeList struct {
+	_ [1]byte
+}
+
 type ProcessInformation struct {
 	Process   Handle
 	Thread    Handle

windows/zsyscall_windows.go

@@ -188,6 +188,7 @@ var (
 	procCreateToolhelp32Snapshot                             = modkernel32.NewProc("CreateToolhelp32Snapshot")
 	procDefineDosDeviceW                                     = modkernel32.NewProc("DefineDosDeviceW")
 	procDeleteFileW                                          = modkernel32.NewProc("DeleteFileW")
+	procDeleteProcThreadAttributeList                        = modkernel32.NewProc("DeleteProcThreadAttributeList")
 	procDeleteVolumeMountPointW                              = modkernel32.NewProc("DeleteVolumeMountPointW")
 	procDeviceIoControl                                      = modkernel32.NewProc("DeviceIoControl")
 	procDuplicateHandle                                      = modkernel32.NewProc("DuplicateHandle")
@@ -266,6 +267,7 @@ var (
 	procGetVolumePathNameW                                   = modkernel32.NewProc("GetVolumePathNameW")
 	procGetVolumePathNamesForVolumeNameW                     = modkernel32.NewProc("GetVolumePathNamesForVolumeNameW")
 	procGetWindowsDirectoryW                                 = modkernel32.NewProc("GetWindowsDirectoryW")
+	procInitializeProcThreadAttributeList                    = modkernel32.NewProc("InitializeProcThreadAttributeList")
 	procIsWow64Process                                       = modkernel32.NewProc("IsWow64Process")
 	procIsWow64Process2                                      = modkernel32.NewProc("IsWow64Process2")
 	procLoadLibraryExW                                       = modkernel32.NewProc("LoadLibraryExW")
@@ -324,6 +326,7 @@ var (
 	procThread32Next                                         = modkernel32.NewProc("Thread32Next")
 	procUnlockFileEx                                         = modkernel32.NewProc("UnlockFileEx")
 	procUnmapViewOfFile                                      = modkernel32.NewProc("UnmapViewOfFile")
+	procUpdateProcThreadAttribute                            = modkernel32.NewProc("UpdateProcThreadAttribute")
 	procVirtualAlloc                                         = modkernel32.NewProc("VirtualAlloc")
 	procVirtualFree                                          = modkernel32.NewProc("VirtualFree")
 	procVirtualLock                                          = modkernel32.NewProc("VirtualLock")
@@ -1574,6 +1577,11 @@ func DeleteFile(path *uint16) (err error) {
 	return
 }
 
+func deleteProcThreadAttributeList(attrlist *ProcThreadAttributeList) {
+	syscall.Syscall(procDeleteProcThreadAttributeList.Addr(), 1, uintptr(unsafe.Pointer(attrlist)), 0, 0)
+	return
+}
+
 func DeleteVolumeMountPoint(volumeMountPoint *uint16) (err error) {
 	r1, _, e1 := syscall.Syscall(procDeleteVolumeMountPointW.Addr(), 1, uintptr(unsafe.Pointer(volumeMountPoint)), 0, 0)
 	if r1 == 0 {
@@ -2235,6 +2243,14 @@ func getWindowsDirectory(dir *uint16, dirLen uint32) (len uint32, err error) {
 	return
 }
 
+func initializeProcThreadAttributeList(attrlist *ProcThreadAttributeList, attrcount uint32, flags uint32, size *uintptr) (err error) {
+	r1, _, e1 := syscall.Syscall6(procInitializeProcThreadAttributeList.Addr(), 4, uintptr(unsafe.Pointer(attrlist)), uintptr(attrcount), uintptr(flags), uintptr(unsafe.Pointer(size)), 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
 func IsWow64Process(handle Handle, isWow64 *bool) (err error) {
 	var _p0 uint32
 	if *isWow64 {
@@ -2776,6 +2792,14 @@ func UnmapViewOfFile(addr uintptr) (err error) {
 	return
 }
 
+func updateProcThreadAttribute(attrlist *ProcThreadAttributeList, flags uint32, attr uintptr, value uintptr, size uintptr, prevvalue uintptr, returnedsize *uintptr) (err error) {
+	r1, _, e1 := syscall.Syscall9(procUpdateProcThreadAttribute.Addr(), 7, uintptr(unsafe.Pointer(attrlist)), uintptr(flags), uintptr(attr), uintptr(value), uintptr(size), uintptr(prevvalue), uintptr(unsafe.Pointer(returnedsize)), 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
 func VirtualAlloc(address uintptr, size uintptr, alloctype uint32, protect uint32) (value uintptr, err error) {
 	r0, _, e1 := syscall.Syscall6(procVirtualAlloc.Addr(), 4, uintptr(address), uintptr(size), uintptr(alloctype), uintptr(protect), 0, 0)
 	value = uintptr(r0)