throw("runtime: wrong goroutine in newstack")
	}

	gp := thisg.m.curg

	if thisg.m.curg.throwsplit {
		// Update syscallsp, syscallpc in case traceback uses them.
		morebuf := thisg.m.morebuf
		gp.syscallsp = morebuf.sp
		gp.syscallpc = morebuf.pc
		pcname, pcoff := "(unknown)", uintptr(0)
		f := findfunc(gp.sched.pc)
		if f.valid() {
			pcname = funcname(f)

	_panic    *_panic // innermost panic - offset known to liblink
	_defer    *_defer // innermost defer
	m         *m      // current m; offset known to arm liblink
	sched     gobuf
	syscallsp uintptr // if status==Gsyscall, syscallsp = sched.sp to use during gc
	syscallpc uintptr // if status==Gsyscall, syscallpc = sched.pc to use during gc
	syscallbp uintptr // if status==Gsyscall, syscallbp = sched.bp to use in fpTraceback

		throw("can't scan our own stack")
	}

	// scannedSize is the amount of work we'll be reporting.
	//
	// It is less than the allocated size (which is hi-lo).
	var sp uintptr
	if gp.syscallsp != 0 {
		sp = gp.syscallsp // If in a system call this is the stack pointer (gp.sched.sp can be 0 in this case on Windows).
	} else {
		sp = gp.sched.sp
	}
	scannedSize := gp.stack.hi - sp

	// stack. However, since we're returning to an earlier stack frame and
	// need to pair with the entersyscall() call made by cgocall, we must
	// save syscall* and let reentersyscall restore them.
	savedsp := unsafe.Pointer(gp.syscallsp)
	savedpc := gp.syscallpc
	savedbp := gp.syscallbp
	exitsyscall() // coming out of cgo call
	gp.m.incgo = false
	if gp.m.isextra {
		gp.m.isExtraInC = false
	}

	osPreemptExtExit(gp.m)

	if mp.locks != 1 || mp.mallocing != 0 || mp.throwing != throwTypeNone || mp.preemptoff != "" || mp.dying != 0 {
		releasem(mp)
		return false
	}
	status := readgstatus(gp)
	if status&^_Gscan != _Grunning || gp.syscallsp != 0 {
		releasem(mp)
		return false
	}
	if GOOS == "windows" && mp.libcallsp != 0 {
		releasem(mp)
		return false
	}
	releasem(mp)
	return true
}