// At this point we're about to call unlockOSThread.
	// The following code must not change to a different m.
	// This is enforced by checking incgo in the schedule function.
	gp.m.incgo = true
	unlockOSThread()

	if gp.m.isextra {
		gp.m.isExtraInC = true
	}

	if gp.m != checkm {
		throw("m changed unexpectedly in cgocallbackg")
	}

	osPreemptExtEnter(gp.m)

	print("Exception ", hex(info.exceptioncode), " ", hex(info.exceptioninformation[0]), " ", hex(info.exceptioninformation[1]), " ", hex(r.ip()), "\n")

	print("PC=", hex(r.ip()), "\n")
	if g0.m.incgo && gp == g0.m.g0 && g0.m.curg != nil {
		if iscgo {
			print("signal arrived during external code execution\n")
		}
		gp = g0.m.curg
	}
	print("\n")

	g0.m.throwing = throwTypeRuntime

	if isSecureMode() {
		exit(2)
	}

	print("PC=", hex(c.sigpc()), " m=", mp.id, " sigcode=", c.sigcode())
	if sig == _SIGSEGV || sig == _SIGBUS {
		print(" addr=", hex(c.fault()))
	}
	print("\n")
	if mp.incgo && gp == mp.g0 && mp.curg != nil {
		print("signal arrived during cgo execution\n")
		// Switch to curg so that we get a traceback of the Go code
		// leading up to the cgocall, which switched from curg to g0.
		gp = mp.curg

			if test == "SegvInCgo" && runtime.GOOS == "ios" {
				testenv.SkipFlaky(t, 59947) // Don't even try, in case it times out.
			}

			t.Parallel()
			prog := "testprog"
			if strings.HasSuffix(test, "InCgo") {
				prog = "testprogcgo"
			}
			got := runTestProg(t, prog, test)
			t.Log(got)
			want := "SIGSEGV"
			if !strings.Contains(got, want) {

	profilehz     int32
	spinning      bool // m is out of work and is actively looking for work
	blocked       bool // m is blocked on a note
	newSigstack   bool // minit on C thread called sigaltstack
	printlock     int8
	incgo         bool          // m is executing a cgo call
	isextra       bool          // m is an extra m
	isExtraInC    bool          // m is an extra m that is not executing Go code

	// Go function, so just assume it's good. Otherwise, traceback
	// may try to read a stale LR that looks like a Go code
	// pointer and wander into the woods.
	if gp.m.incgo || findfunc(pc).valid() {
		// This wasn't a bad call, so use PC as sigpanic's
		// return PC.
		return true
	}
	if findfunc(lr).valid() {
		// This was a bad call, but the LR is good, so use the

		// get everything, so crash loudly.
		fail := u.flags&(unwindPrintErrors|unwindSilentErrors) == 0
		doPrint := u.flags&unwindSilentErrors == 0
		if doPrint && gp.m.incgo && f.funcID == abi.FuncID_sigpanic {
			// We can inject sigpanic
			// calls directly into C code,
			// in which case we'll see a C
			// return PC. Don't complain.
			doPrint = false
		}

	// start.
	acquirem()

	mp := allocm(pp, fn, id)
	mp.nextp.set(pp)
	mp.sigmask = initSigmask
	if gp := getg(); gp != nil && gp.m != nil && (gp.m.lockedExt != 0 || gp.m.incgo) && GOOS != "plan9" {
		// We're on a locked M or a thread that may have been
		// started by C. The kernel state of this thread may
		// be strange (the user may have locked it for that