// Pop BP from the stack to simulate it.
	POPQ	BP
	JMP	DI

bad:
	// Bad: g is not gsignal, not g0, not curg. What is it?
	MOVQ	$runtime·badsystemstack(SB), AX
	CALL	AX
	INT	$3

// func switchToCrashStack0(fn func())
TEXT runtime·switchToCrashStack0<ABIInternal>(SB), NOSPLIT, $0-8
	MOVQ	g_m(R14), BX // curm

	// set g to gcrash
	LEAQ	runtime·gcrash(SB), R14 // g = &gcrash

// morestack would fail).
//
//go:nosplit
//go:nowritebarrierrec
func switchToCrashStack(fn func()) {
	me := getg()
	if crashingG.CompareAndSwapNoWB(nil, me) {
		switchToCrashStack0(fn) // should never return
		abort()
	}
	if crashingG.Load() == me {
		// recursive crashing. too bad.
		writeErrStr("fatal: recursive switchToCrashStack\n")
		abort()
	}