func execve(path *byte, argv **byte, envp **byte) (err error) {
	_, _, e1 := rawSyscall(abi.FuncPCABI0(libc_execve_trampoline), uintptr(unsafe.Pointer(path)), uintptr(unsafe.Pointer(argv)), uintptr(unsafe.Pointer(envp)))
	if e1 != 0 {
		err = errnoErr(e1)
	}
	return
}

func libc_execve_trampoline()

//go:cgo_import_dynamic libc_execve execve "libc.so"

	if err != nil {
		return err
	}
	if nonblocking {
		flag |= O_NONBLOCK
	} else {
		flag &= ^O_NONBLOCK
	}
	_, err = fcntl(fd, F_SETFL, flag)
	return err
}

// Exec calls execve(2), which replaces the calling executable in the process
// tree. argv0 should be the full path to an executable ("/bin/ls") and the
// executable name should also be the first argument in argv (["ls", "-l"]).