ready(mp)

	// Wait for the signal. We use a pipe rather than a note
	// because write is always async-signal-safe.
	entersyscallblock()
	var b byte
	read(waitForSigusr1.rdpipe, noescape(unsafe.Pointer(&b)), 1)
	exitsyscall()

	gotM := waitForSigusr1.mID
	testSigusr1 = nil

	unlockOSThread()

	if b != 0 {
		// timeout signal from caller
		return -1, -1
	}
	return mp.id, gotM
}

			physPageSize = val
		}
	}
	return i / 2
}

// raise sends a signal to the calling thread.
//
// It must be nosplit because it is used by the signal handler before
// it definitely has a Go stack.
//
//go:nosplit
func raise(sig uint32) {
	lwp_kill(-1, lwp_gettid(), int(sig))
}

func signalM(mp *m, sig int) {
	lwp_kill(-1, int32(mp.procid), sig)
}

		throw("remapping stack memory failed")
	}
}

//go:nosplit
func raise(sig uint32) {
	thrkill(getthrid(), int(sig))
}

func signalM(mp *m, sig int) {
	thrkill(int32(mp.procid), sig)
}

// sigPerThreadSyscall is only used on linux, so we assign a bogus signal
// number.
const sigPerThreadSyscall = 1 << 31

//go:nosplit
func runPerThreadSyscall() {
	throw("runPerThreadSyscall only valid on linux")

func getpid() int
func tgkill(tgid, tid, sig int)

// signalM sends a signal to mp.
func signalM(mp *m, sig int) {
	tgkill(getpid(), int(mp.procid), sig)
}

// validSIGPROF compares this signal delivery's code against the signal sources
// that the profiler uses, returning whether the delivery should be processed.
// To be processed, a signal delivery from a known profiling mechanism should

// created thread. On NetBSD, a new thread inherits the signal stack
// of the creating thread. That confuses minit, so we remove that
// signal stack here before calling the regular mstart. It's a bit
// baroque to remove a signal stack here only to add one in minit, but
// it's a simple change that keeps NetBSD working like other OS's.
// At this point all signals are blocked, so there is no race.
//
//go:nosplit

func mpreinit(mp *m) {
	mp.gsignal = malg(32 * 1024) // OS X wants >= 8K
	mp.gsignal.m = mp
	if GOOS == "darwin" && GOARCH == "arm64" {
		// mlock the signal stack to work around a kernel bug where it may
		// SIGILL when the signal stack is not faulted in while a signal
		// arrives. See issue 42774.
		mlock(unsafe.Pointer(mp.gsignal.stack.hi-physPageSize), physPageSize)
	}
}

			t.Errorf("pipe write failed: %d", n)
		}
	})
	defer timer.Stop()

	wg.Wait()
	if got == -1 {
		t.Fatal("signalM signal not received")
	} else if want != got {
		t.Fatalf("signal sent to M %d, but received on M %d", want, got)
	}

//
//go:noescape
func asmSigaction(sig uintptr, new, old *sigactiont) int32

// raise sends a signal to the calling thread.
//
// It must be nosplit because it is used by the signal handler before
// it definitely has a Go stack.
//
//go:nosplit
func raise(sig uint32) {
	thr_kill(thr_self(), int(sig))
}

func signalM(mp *m, sig int) {
	thr_kill(thread(mp.procid), sig)
}

	}
	mp.g0.stack.lo = mp.g0.stack.hi - uintptr(size)
	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
		throw("pthread_attr_setdetachstate")
	}

	// Disable signals during create, so that the new thread starts
	// with signals disabled. It will enable them in minit.
	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
	ret = retryOnEAGAIN(func() int32 {

}

//go:nosplit
func pthread_self() pthread {
	r, _ := syscall0(&libpthread_self)
	return pthread(r)
}

//go:nosplit
func signalM(mp *m, sig int) {
	syscall2(&libpthread_kill, uintptr(pthread(mp.procid)), uintptr(sig))