func kevent_trampoline()

//go:nosplit
//go:cgo_unsafe_args
func sigaction(sig uint32, new *sigactiont, old *sigactiont) {
	libcCall(unsafe.Pointer(abi.FuncPCABI0(sigaction_trampoline)), unsafe.Pointer(&sig))
	KeepAlive(new)
	KeepAlive(old)
}
func sigaction_trampoline()

//go:nosplit
//go:cgo_unsafe_args
func sigprocmask(how uint32, new *sigset, old *sigset) {
	// sigprocmask is called from sigsave, which is called from needm.