func main() {
	if len(os.Args) > 1 {
		// Generate a SIGILL.
		sigill()
		return
	}
	// Run ourselves with an extra argument. That process should SIGILL.
	out, _ := exec.Command(os.Args[0], "foo").CombinedOutput()
	want := "instruction bytes: 0xf 0xb 0xc3"
	if !bytes.Contains(out, []byte(want)) {
		fmt.Printf("got:\n%s\nwant:\n%s\n", string(out), want)
	}
}

// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

TEXT ·sigill(SB),0,$0-0
	UD2	// generates a SIGILL

	// The strategy here is to call some EABI syscall to see if
	// SIGILL is received.
	// If you get a SIGILL here, you have the wrong kernel.

	// Save argc and argv (syscall will clobber at least R0).
	MOVM.DB.W [R0-R1], (R13)

	// do an EABI syscall
	MOVW	$20, R7 // sys_getpid
	SWI	$0 // this will trigger SIGILL on OABI systems

	MOVM.IA.W (R13), [R0-R1]

	ARM64.HasCPUID = isSet(HWCap, hwcap_CPUID)
	ARM64.HasSHA512 = isSet(HWCap, hwcap_SHA512)

	// The Samsung S9+ kernel reports support for atomics, but not all cores
	// actually support them, resulting in SIGILL. See issue #28431.
	// TODO(elias.naur): Only disable the optimization on bad chipsets on android.
	ARM64.HasATOMICS = isSet(HWCap, hwcap_ATOMICS) && os != "android"

	MADV_FREE     = C.MADV_FREE

	SA_SIGINFO = C.SA_SIGINFO
	SA_RESTART = C.SA_RESTART
	SA_ONSTACK = C.SA_ONSTACK

	SIGHUP    = C.SIGHUP
	SIGINT    = C.SIGINT
	SIGQUIT   = C.SIGQUIT
	SIGILL    = C.SIGILL
	SIGTRAP   = C.SIGTRAP
	SIGABRT   = C.SIGABRT
	SIGEMT    = C.SIGEMT
	SIGFPE    = C.SIGFPE
	SIGKILL   = C.SIGKILL
	SIGBUS    = C.SIGBUS
	SIGSEGV   = C.SIGSEGV
	SIGSYS    = C.SIGSYS
	SIGPIPE   = C.SIGPIPE

	SA_RESTART = C.SA_RESTART
	SA_ONSTACK = C.SA_ONSTACK
	SA_SIGINFO = C.SA_SIGINFO

	SI_KERNEL = C.SI_KERNEL
	SI_TIMER  = C.SI_TIMER

	SIGHUP    = C.SIGHUP
	SIGINT    = C.SIGINT
	SIGQUIT   = C.SIGQUIT
	SIGILL    = C.SIGILL
	SIGTRAP   = C.SIGTRAP
	SIGABRT   = C.SIGABRT
	SIGBUS    = C.SIGBUS
	SIGFPE    = C.SIGFPE
	SIGKILL   = C.SIGKILL
	SIGUSR1   = C.SIGUSR1
	SIGSEGV   = C.SIGSEGV
	SIGUSR2   = C.SIGUSR2

	SA_RESTART  = C.SA_RESTART
	SA_ONSTACK  = C.SA_ONSTACK
	SA_RESTORER = C.SA_RESTORER
	SA_SIGINFO  = C.SA_SIGINFO

	SIGHUP    = C.SIGHUP
	SIGINT    = C.SIGINT
	SIGQUIT   = C.SIGQUIT
	SIGILL    = C.SIGILL
	SIGTRAP   = C.SIGTRAP
	SIGABRT   = C.SIGABRT
	SIGBUS    = C.SIGBUS
	SIGFPE    = C.SIGFPE
	SIGKILL   = C.SIGKILL
	SIGUSR1   = C.SIGUSR1
	SIGSEGV   = C.SIGSEGV
	SIGUSR2   = C.SIGUSR2

	MADV_FREE     = C.MADV_FREE

	SA_SIGINFO = C.SA_SIGINFO
	SA_RESTART = C.SA_RESTART
	SA_ONSTACK = C.SA_ONSTACK

	SIGHUP    = C.SIGHUP
	SIGINT    = C.SIGINT
	SIGQUIT   = C.SIGQUIT
	SIGILL    = C.SIGILL
	SIGTRAP   = C.SIGTRAP
	SIGABRT   = C.SIGABRT
	SIGEMT    = C.SIGEMT
	SIGFPE    = C.SIGFPE
	SIGKILL   = C.SIGKILL
	SIGBUS    = C.SIGBUS
	SIGSEGV   = C.SIGSEGV
	SIGSYS    = C.SIGSYS
	SIGPIPE   = C.SIGPIPE

	SA_RESTART  = C.SA_RESTART
	SA_ONSTACK  = C.SA_ONSTACK
	SA_RESTORER = C.SA_RESTORER
	SA_SIGINFO  = C.SA_SIGINFO

	SIGHUP    = C.SIGHUP
	SIGINT    = C.SIGINT
	SIGQUIT   = C.SIGQUIT
	SIGILL    = C.SIGILL
	SIGTRAP   = C.SIGTRAP
	SIGABRT   = C.SIGABRT
	SIGBUS    = C.SIGBUS
	SIGFPE    = C.SIGFPE
	SIGKILL   = C.SIGKILL
	SIGUSR1   = C.SIGUSR1
	SIGSEGV   = C.SIGSEGV
	SIGUSR2   = C.SIGUSR2

	SA_SIGINFO = C.SA_SIGINFO
	SA_RESTART = C.SA_RESTART
	SA_ONSTACK = C.SA_ONSTACK

	PTHREAD_CREATE_DETACHED = C.PTHREAD_CREATE_DETACHED

	SIGHUP    = C.SIGHUP
	SIGINT    = C.SIGINT
	SIGQUIT   = C.SIGQUIT
	SIGILL    = C.SIGILL
	SIGTRAP   = C.SIGTRAP
	SIGABRT   = C.SIGABRT
	SIGEMT    = C.SIGEMT
	SIGFPE    = C.SIGFPE
	SIGKILL   = C.SIGKILL
	SIGBUS    = C.SIGBUS
	SIGSEGV   = C.SIGSEGV
	SIGSYS    = C.SIGSYS
	SIGPIPE   = C.SIGPIPE