// save that information (m->curg->sched) so we can restore it.
	// We can restore m->curg->sched.sp easily, because calling
	// runtime.cgocallbackg leaves SP unchanged upon return.
	// To save m->curg->sched.pc, we push it onto the curg stack and
	// open a frame the same size as cgocallback's g0 frame.
	// Once we switch to the curg stack, the pushed PC will appear
	// to be the return PC of cgocallback, so that the traceback

	// switch back to m->curg stack.
	// NOTE: unwindm knows that the saved g->sched.sp is at 8(R29) aka savedsp-16(SP).
	MOVV	m_g0(R12), R19
	MOVV	(g_sched+gobuf_sp)(R19), R13
	MOVV	R13, savedsp-24(SP) // must match frame size
	MOVV	R3, (g_sched+gobuf_sp)(R19)

	// Switch to m->curg stack and call runtime.cgocallbackg.
	// Because we are taking over the execution of m->curg

		goroutineheader(gp)
		tracebacktrap(c.sigpc(), c.sigsp(), c.siglr(), gp)
		if crashing.Load() > 0 && gp != mp.curg && mp.curg != nil && readgstatus(mp.curg)&^_Gscan == _Grunning {
			// tracebackothers on original m skipped this one; trace it now.
			goroutineheader(mp.curg)
			traceback(^uintptr(0), ^uintptr(0), 0, mp.curg)
		} else if crashing.Load() == 0 {
			tracebackothers(gp)
			print("\n")
		}
		dumpregs(c)
	}

	// save that information (m->curg->sched) so we can restore it.
	// We can restore m->curg->sched.sp easily, because calling
	// runtime.cgocallbackg leaves SP unchanged upon return.
	// To save m->curg->sched.pc, we push it onto the curg stack and
	// open a frame the same size as cgocallback's g0 frame.
	// Once we switch to the curg stack, the pushed PC will appear
	// to be the return PC of cgocallback, so that the traceback

// the signal case.
//
//go:systemstack
func suspendG(gp *g) suspendGState {
	if mp := getg().m; mp.curg != nil && readgstatus(mp.curg) == _Grunning {
		// Since we're on the system stack of this M, the user
		// G is stuck at an unsafe point. If another goroutine
		// were to try to preempt m.curg, it could deadlock.
		throw("suspendG from non-preemptible goroutine")
	}

func racefree(p unsafe.Pointer, sz uintptr) {
	racecall(&__tsan_free, uintptr(p), sz, 0, 0)
}

//go:nosplit
func racegostart(pc uintptr) uintptr {
	gp := getg()
	var spawng *g
	if gp.m.curg != nil {
		spawng = gp.m.curg
	} else {
		spawng = gp
	}

	var racectx uintptr
	racecall(&__tsan_go_start, spawng.racectx, uintptr(unsafe.Pointer(&racectx)), pc, 0)
	return racectx
}

//go:nosplit

	// but *not* resuming what had been running, we need to
	// save that information (m->curg->sched) so we can restore it.
	// We can restore m->curg->sched.sp easily, because calling
	// runtime.cgocallbackg leaves SP unchanged upon return.
	// To save m->curg->sched.pc, we push it onto the curg stack and
	// open a frame the same size as cgocallback's g0 frame.
	// Once we switch to the curg stack, the pushed PC will appear

	}
	if thisg.m.morebuf.g.ptr() != thisg.m.curg {
		print("runtime: newstack called from g=", hex(thisg.m.morebuf.g), "\n"+"\tm=", thisg.m, " m->curg=", thisg.m.curg, " m->g0=", thisg.m.g0, " m->gsignal=", thisg.m.gsignal, "\n")
		morebuf := thisg.m.morebuf
		traceback(morebuf.pc, morebuf.sp, morebuf.lr, morebuf.g.ptr())
		throw("runtime: wrong goroutine in newstack")
	}

	gp := thisg.m.curg

	if thisg.m.curg.throwsplit {

func traceStack(skip int, gp *g, gen uintptr) uint64 {
	var pcBuf [traceStackSize]uintptr

	// Figure out gp and mp for the backtrace.
	var mp *m
	if gp == nil {
		mp = getg().m
		gp = mp.curg
	}

	// Double-check that we own the stack we're about to trace.
	if debug.traceCheckStackOwnership != 0 && gp != nil {
		status := readgstatus(gp)
		// If the scan bit is set, assume we're the ones that acquired it.

// taken from the frame structure, records the results in the frame,
// and returns to runtime.asmcgocall.
//
// After it regains control, runtime.asmcgocall switches back to the
// original g (m->curg)'s stack and returns to runtime.cgocall.
//
// After it regains control, runtime.cgocall calls exitsyscall, which blocks
// until this m can run Go code without violating the $GOMAXPROCS limit,
// and then unlocks g from m.
//