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kernel_thread(kernel_init, NULL, CLONE_FS);1

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static noinline void __init kernel_init_freeable(void)
{
    /*
     * Wait until kthreadd is all set-up.
     */
    wait_for_completion(&kthreadd_done);

    /* Now the scheduler is fully set up and can do blocking allocations */
    gfp_allowed_mask = __GFP_BITS_MASK;

    /*
     * init can allocate pages on any node
     */
    set_mems_allowed(node_states[N_MEMORY]);
    /*
     * init can run on any cpu.
     */
    set_cpus_allowed_ptr(current, cpu_all_mask);

    cad_pid = task_pid(current);

    smp_prepare_cpus(setup_max_cpus);

    do_pre_smp_initcalls();
    lockup_detector_init();

    smp_init();
    sched_init_smp();

    page_alloc_init_late();

    do_basic_setup();

    /* Open the /dev/console on the rootfs, this should never fail */
    if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
            pr_err("Warning: unable to open an initial console.\n");

    (void) sys_dup(0);
    (void) sys_dup(0);
    /*
     * check if there is an early userspace init.  If yes, let it do all
     * the work
     */

    if (!ramdisk_execute_command)
            ramdisk_execute_command = "/init";

    if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
            ramdisk_execute_command = NULL;
            prepare_namespace();
    }

    /*
     * Ok, we have completed the initial bootup, and
     * we're essentially up and running. Get rid of the
     * initmem segments and start the user-mode stuff..
     *
     * rootfs is available now, try loading the public keys
     * and default modules
     */

    integrity_load_keys();
    load_default_modules();
 }

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static int __ref kernel_init(void *unused)
{
    int ret;

    kernel_init_freeable();
    /* need to finish all async __init code before freeing the memory */
    async_synchronize_full();
    free_initmem();
    mark_rodata_ro();
    system_state = SYSTEM_RUNNING;
    numa_default_policy();

    flush_delayed_fput();

    rcu_end_inkernel_boot();

    if (ramdisk_execute_command) {
            ret = run_init_process(ramdisk_execute_command);
            if (!ret)
                    return 0;
            pr_err("Failed to execute %s (error %d)\n",
                   ramdisk_execute_command, ret);
    }

    /*
     * We try each of these until one succeeds.
     *
     * The Bourne shell can be used instead of init if we are
     * trying to recover a really broken machine.
     */
    if (execute_command) {
            ret = run_init_process(execute_command);
            if (!ret)
                    return 0;
            panic("Requested init %s failed (error %d).",
                  execute_command, ret);
    }
    if (!try_to_run_init_process("/sbin/init") ||
        !try_to_run_init_process("/etc/init") ||
        !try_to_run_init_process("/bin/init") ||
        !try_to_run_init_process("/bin/sh"))
            return 0;

    panic("No working init found.  Try passing init= option to kernel. "
          "See Linux Documentation/init.txt for guidance.");
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